drivers: shrm: Add shared memory (shrm) driver

Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>

16 files changed, 6072 insertions, 0 deletions

diff --git a/Documentation/DocBook/shrm.tmpl b/Documentation/DocBook/shrm.tmpl
new file mode 100644
index 00000000000..b35e1bc4e0b
--- /dev/null
+++ b/Documentation/DocBook/shrm.tmpl
@@ -0,0 +1,139 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
+	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
+
+<book id="SHRM">
+ <bookinfo>
+  <title>Shared Memory</title>
+  <authorgroup>
+   <author>
+    <firstname>Biju</firstname>
+    <surname>Das</surname>
+    <affiliation>
+     <address>
+      <email>biju.das@stericsson.com</email>
+     </address>
+    </affiliation>
+   </author>
+   <author>
+    <firstname>Kumar</firstname>
+    <surname>Sanghvi</surname>
+    <affiliation>
+     <address>
+      <email>kumar.sanghvi@stericsson.com</email>
+     </address>
+    </affiliation>
+   </author>
+   <author>
+    <firstname>Arun</firstname>
+    <surname>Murthy</surname>
+    <affiliation>
+     <address>
+      <email>arun.murthy@stericsson.com</email>
+     </address>
+    </affiliation>
+   </author>
+   </authorgroup>
+
+  <copyright>
+   <year>2009-2010</year>
+   <holder>ST-Ericsson</holder>
+  </copyright>
+
+  <subjectset>
+    <subject>
+      <subjectterm>Linux standard functions</subjectterm>
+    </subject>
+  </subjectset>
+
+  <legalnotice>
+   <!-- Do NOT remove the legal notice below -->
+   <para>
+     Licence terms: GNU General Public Licence (GPL) version 2.
+   </para>
+  </legalnotice>
+ </bookinfo>
+
+<toc></toc>
+  <chapter id="intro">
+    <title>Introduction</title>
+    <para>
+	This Documentation describes the ST-Ericsson's adaptation on protocol used for CMT/APE communication when SHaRedMemory is used as IPC link.
+    </para>
+  </chapter>
+
+  <chapter id="design">
+    <title>Design</title>
+    <para>
+	The APE consists Cortex A9 dual core SMP, a multimedia DSP and PRCMU. Modem consists of 2 Cortex R4 ARM processor.
+	The exchange of messages between CMT(Cellular Mobile Terminal) and APE includes copying the data to a shared area DDR. This region is accessible by both CMT and APE. The design includes 2 channels common and audio. Common channel is used for exchanging ISI, RPC and SECURITY messages. Audio channel is used for exchanging AUDIO messages. Each channel consists of 2 FIFO. One FIFO for sending message from CMT to APE and other from APE to CMT. Each of these FIFO have write and read pointer shared between APE and CMT. Writer pointer is updated on copying the message to FIFO and reader will read the messages from the read pointer upto the writer pointer. Writer and reader notifications are used to notify the completion of read/write operation(seperate for APE and CMT). Driver includes 4 queues. Once the messages are sent from CMT to APE it resides in the FIFO and then copied to one of the 4 queues based on the message type(ISI, RPC, AUDIO, SECURITY) and then the net/char device interface fetches this message from the queue and copies to the user space buffer.
+    </para>
+  </chapter>
+
+  <chapter id="concepts">
+    <title>Concepts</title>
+    <para>
+	The user space application sends ISI/RPC/AUDIO/SECURITY messages. ISI is sent through the phonet to shrm driver. For achieving this there are 2 interfaces to the shrm driver. Net interface used for exchanging the ISI message and char interface for RPC, AUDIO and SECURITY messages. On receiving any of these messages from the user space application, it is copied to a memory in kernel space. From here it is then copied to respective FIFO from where the CMT reads the message.
+	CMT(Cellular Mobile Terminal) writes messages to the respective FIFO and thereafter to respective queue. The net/char device copies this message from the queue to the user space buffer.
+    </para>
+  </chapter>
+
+  <chapter id="bugs">
+     <title>Known Bugs And Assumptions</title>
+  <para>
+     <variablelist>
+     <varlistentry>
+       <term>None</term>
+       <listitem>
+         <para>
+		Assumptions
+		1. ApeShmFifo#0 is of 128kB in size. As this is used for transmission except CS audio call data. Expected message size is 1.5kB with a max of 16kB.
+		2. ApeShmFifo#1 is of 4kB in size. This is used for transmission of CS audio call data. Expected message size is 24kb.
+		3. CmtShmFifo#0 is of 128kB in size. As this is used for transmission except CS audio call data. Expected message size is 1.5kB with a max of 16kB.
+		4. CmtShmFifo#1 is of 4kB in size. This is used for transmission of CS audio call data. Expected message size is 24kb.
+		The total size of the FIFO is 264 kB.
+         </para>
+       </listitem>
+     </varlistentry>
+     </variablelist>
+  </para>
+  </chapter>
+
+  <chapter id="pubfunctions">
+     <title>Public Functions Provided</title>
+     <para>
+	This Section lists the API's provided by the SHRM driver to phonet drivers.
+     </para>
+!Edrivers/net/u8500_shrm.c
+     <para>
+	This Section lists the API's provided by the SHRM driver used in transmission of RPC, AUDIO and SECURITY messages.
+     </para>
+!Edrivers/char/shrm_char.c
+  </chapter>
+
+  <chapter id="private">
+    <title>Private Functions</title>
+    <para>
+	This Section lists the functions used internally by the SHRM driver to implement FIFO management. It physically reads/writes data to/from memory.
+    </para>
+!Idrivers/misc/shrm/shrm_fifo.c
+    <para>
+	This Section lists the functions used internally by the SHRM driver to implement the SHM protocol and handle all interrupt callback.
+    </para>
+!Idrivers/misc/shrm/shrm_protocol.c
+    <para>
+	This Section lists the functions used internally by the SHRM driver to implement Modem-Host communication L1 interface specifications.
+    </para>
+!Idrivers/misc/shrm/modem_shrm_driver.c
+  </chapter>
+
+  <chapter id="Other">
+    <title>Other Data Structures</title>
+    <para>
+	This Section lists some of the Data structure used by the SHRM driver.
+    </para>
+!Iarch/arm/mach-ux500/include/mach/shrm.h
+!Iarch/arm/mach-ux500/include/mach/shrm_driver.h
+!Iarch/arm/mach-ux500/include/mach/shrm_private.h
+  </chapter>
+</book>
diff --git a/arch/arm/mach-ux500/include/mach/shrm.h b/arch/arm/mach-ux500/include/mach/shrm.h
new file mode 100644
index 00000000000..6deeeb16ba8
--- /dev/null
+++ b/arch/arm/mach-ux500/include/mach/shrm.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghavi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef __SHM_DRIVER_IF_H__
+#define __SHM_DRIVER_IF_H__
+
+#include <linux/device.h>
+
+/* forward declaration */
+struct shrm_dev;
+
+typedef void (*rx_cb)(void *data, unsigned int length);
+typedef void (*received_msg_handler)(unsigned char l2_header,
+			void *msg_ptr, unsigned int length,
+			struct shrm_dev *shrm);
+
+#endif
diff --git a/arch/arm/mach-ux500/include/mach/shrm_config.h b/arch/arm/mach-ux500/include/mach/shrm_config.h
new file mode 100644
index 00000000000..a82b35ef77b
--- /dev/null
+++ b/arch/arm/mach-ux500/include/mach/shrm_config.h
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghavi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef __SHRM_CONFIG_H
+#define __SHRM_CONFIG_H
+
+
+/*
+Note: modem need to define IPC as a non-cacheable area.
+In Cortex R4 MPU requires that base address of NC area is aligned on a
+region-sized boundary.On modem side, only 1 NC area can be defined, hence
+the whole IPC area must be defined as NC (at least).
+
+*/
+
+/* cache line size = 32bytes*/
+#define SHM_CACHE_LINE 32
+#define SHM_PTR_SIZE 4
+
+/* FIFO 0 address configuration */
+/* ---------------------------- */
+/* 128KB */
+#define SHM_FIFO_0_SIZE (128*1024)
+
+
+/* == APE addresses == */
+#ifdef CONFIG_SHRM_V1_UPDATES_VERSION
+#define SHM_IPC_BASE_AMCU 0x06F80000
+#else
+#define SHM_IPC_BASE_AMCU 0x06000000
+#endif
+
+/* offset pointers */
+#define SHM_ACFIFO_0_WRITE_AMCU SHM_IPC_BASE_AMCU
+#define SHM_ACFIFO_0_READ_AMCU (SHM_ACFIFO_0_WRITE_AMCU + SHM_PTR_SIZE)
+#define SHM_CAFIFO_0_WRITE_AMCU (SHM_ACFIFO_0_WRITE_AMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_0_READ_AMCU (SHM_CAFIFO_0_WRITE_AMCU + SHM_PTR_SIZE)
+/* FIFO start */
+#define SHM_ACFIFO_0_START_AMCU (SHM_CAFIFO_0_WRITE_AMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_0_START_AMCU (SHM_ACFIFO_0_START_AMCU + SHM_FIFO_0_SIZE)
+
+
+/* == CMT addresses ==*/
+#define SHM_IPC_BASE_CMCU (SHM_IPC_BASE_AMCU+0x08000000)
+/* offset pointers */
+#define SHM_ACFIFO_0_WRITE_CMCU SHM_IPC_BASE_CMCU
+#define SHM_ACFIFO_0_READ_CMCU (SHM_ACFIFO_0_WRITE_CMCU + SHM_PTR_SIZE)
+#define SHM_CAFIFO_0_WRITE_CMCU (SHM_ACFIFO_0_WRITE_CMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_0_READ_CMCU (SHM_CAFIFO_0_WRITE_CMCU + SHM_PTR_SIZE)
+/* FIFO*/
+#define SHM_ACFIFO_0_START_CMCU (SHM_CAFIFO_0_WRITE_CMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_0_START_CMCU (SHM_ACFIFO_0_START_CMCU + SHM_FIFO_0_SIZE)
+
+
+/* ADSP addresses*/
+#define SHM_ACFIFO_0_START_ADSP 0x0
+#define SHM_CAFIFO_0_START_ADSP 0x0
+#define SHM_ACFIFO_0_WRITE_ADSP 0x0
+#define SHM_ACFIFO_0_READ_ADSP 0x0
+#define SHM_CAFIFO_0_WRITE_ADSP 0x0
+#define SHM_CAFIFO_0_READ_ADSP 0x0
+
+/* FIFO 1 address configuration */
+/* ---------------------------- */
+
+
+/* FIFO 1 - 4K  */
+#define SHM_FIFO_1_SIZE (4*1024)
+
+
+/* == APE addresses == */
+#define SHM_ACFIFO_1_WRITE_AMCU (SHM_CAFIFO_0_START_AMCU + SHM_FIFO_0_SIZE)
+#define SHM_ACFIFO_1_READ_AMCU (SHM_ACFIFO_1_WRITE_AMCU + SHM_PTR_SIZE)
+#define SHM_CAFIFO_1_WRITE_AMCU (SHM_ACFIFO_1_WRITE_AMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_1_READ_AMCU (SHM_CAFIFO_1_WRITE_AMCU + SHM_PTR_SIZE)
+/* FIFO*/
+#define SHM_ACFIFO_1_START_AMCU (SHM_CAFIFO_1_WRITE_AMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_1_START_AMCU (SHM_ACFIFO_1_START_AMCU + SHM_FIFO_1_SIZE)
+
+
+/* == CMT addresses ==*/
+#define SHM_ACFIFO_1_WRITE_CMCU (SHM_CAFIFO_0_START_CMCU + SHM_FIFO_0_SIZE)
+#define SHM_ACFIFO_1_READ_CMCU (SHM_ACFIFO_1_WRITE_CMCU + SHM_PTR_SIZE)
+#define SHM_CAFIFO_1_WRITE_CMCU (SHM_ACFIFO_1_WRITE_CMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_1_READ_CMCU (SHM_CAFIFO_1_WRITE_CMCU + SHM_PTR_SIZE)
+/* FIFO1 start */
+#define SHM_ACFIFO_1_START_CMCU (SHM_CAFIFO_1_WRITE_CMCU + SHM_CACHE_LINE)
+#define SHM_CAFIFO_1_START_CMCU (SHM_ACFIFO_1_START_CMCU + SHM_FIFO_1_SIZE)
+
+
+/* ADSP addresses*/
+#define SHM_ACFIFO_1_START_ADSP 0x0
+#define SHM_CAFIFO_1_START_ADSP 0x0
+#define SHM_ACFIFO_1_WRITE_ADSP 0x0
+#define SHM_ACFIFO_1_READ_ADSP 0x0
+#define SHM_CAFIFO_1_WRITE_ADSP 0x0
+#define SHM_CAFIFO_1_READ_ADSP 0x0
+
+
+#define U8500_SHM_FIFO_APE_COMMON_BASE  (SHM_ACFIFO_0_START_AMCU)
+#define U8500_SHM_FIFO_CMT_COMMON_BASE  (SHM_CAFIFO_0_START_AMCU)
+#define U8500_SHM_FIFO_APE_AUDIO_BASE   (SHM_ACFIFO_1_START_AMCU)
+#define U8500_SHM_FIFO_CMT_AUDIO_BASE   (SHM_CAFIFO_1_START_AMCU)
+
+#endif /* __SHRM_CONFIG_H */
diff --git a/arch/arm/mach-ux500/include/mach/shrm_driver.h b/arch/arm/mach-ux500/include/mach/shrm_driver.h
new file mode 100644
index 00000000000..41f518238b3
--- /dev/null
+++ b/arch/arm/mach-ux500/include/mach/shrm_driver.h
@@ -0,0 +1,201 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghavi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef __SHRM_DRIVER_H__
+#define __SHRM_DRIVER_H__
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+
+#include <mach/shrm.h>
+
+#include <linux/cdev.h>
+
+#define ISA_DEVICES 6
+
+#define BOOT_INIT  (0)
+#define BOOT_INFO_SYNC  (1)
+#define BOOT_DONE  (2)
+#define BOOT_UNKNOWN (3)
+
+/**
+ * struct shrm_dev - shrm device information
+ * @ca_wake_irq:		CMT wake interrupt number
+ * @ac_read_notif_0_irq:	ape-cmt common channel read notify interrupt
+ * @ac_read_notif_1_irq:	ape-cmt audio channel read notify interrupt
+ * @ca_msg_pending_notif_0_irq:	cmt-ape common channel msg pending interrupt
+ * @ca_msg_pending_notif_1_irq:	cmt-ape audio channel msg pending interrupt
+ * @intr_base:			interrupt base register address
+ * @ape_common_fifo_base:	ape side common channel fifo base addr
+ * @ape_audio_fifo_base:	ape side audio channel fifo base addr
+ * @cmt_common_fifo_base:	cmt side common channel fifo base addr
+ * @cmt_audio_fifo_base:	cmt side audio channel fifo base addr
+ * @ape_common_fifo_base_phy:	physical addr of ape common fifo
+ * @ape_audio_fifo_base_phy:	physical addr of ape audio fifo
+ * @cmt_common_fifo_base_phy:	physical addr of cmt common fifo
+ * @cmt_audio_fifo_base_phy:	physical addr of cmt audio fifo
+ * @ape_common_fifo_size:	ape side common channel fifo size
+ * @ape_audio_fifo_size:	ape side audio channel fifo size
+ * @cmt_common_fifo_size:	cmt side common channel fifo size
+ * @cmt_audio_fifo_size:	cmt side audio channel fifo size
+ * @netdev_flag_up:		flag to indicate up/down of netwok device
+ * @msr_flag:			flag to check on-going MSR sequence
+ * @ac_common_shared_wptr:	ape-cmt common channel write pointer
+ * @ac_common_shared_rptr:	ape-cmt common channel read pointer
+ * @ca_common_shared_wptr:	cmt-ape common channel write pointer
+ * @ca_common_shared_rptr:	cmt-ape common channel read pointer
+ * @ac_audio_shared_wptr:	ape-cmt audio channel write pointer
+ * @ac_audio_shared_rptr:	ape-cmt audio channel read pointer
+ * @ca_audio_shared_wptr:	cmt-ape audio channel write pointer
+ * @ca_audio_shared_rptr:	cmt-ape audio channel read pointer
+ * @dev:			pointer to the driver device
+ * @ndev:			pointer to the network device structure
+ * @isa_context:		pointer to t_isa_driver_sontext dtructure
+ * @shm_common_ch_wr_wq:	work queue for writing to common channel
+ * @shm_audio_ch_wr_wq:		workqueue for writing to audio channel
+ * @shm_ac_wake_wq:		workqueue for receiving ape-cmt wake requests
+ * @shm_ca_wake_wq:		workqueue for receiving cmt-ape wake requests
+ * @shm_ac_sleep_wq:		workqueue for recieving ape-cmt sleep requests
+ * @send_ac_msg_pend_notify_0:	work for handling pending message on common
+ * channel
+ * @send_ac_msg_pend_notify_1:	work for handling pending message on audio
+ * channel
+ * @shm_ac_wake_req:		work to send ape-cmt wake request
+ * @shm_ca_wake_req:		work to send cmt-ape wake request
+ * @shm_ca_sleep_req:		work to send cmt-ape sleep request
+ * @shm_ac_sleep_req:		work to send ape-cmt sleep request
+ */
+struct shrm_dev {
+	u8 ca_wake_irq;
+	u8 ac_read_notif_0_irq;
+	u8 ac_read_notif_1_irq;
+	u8 ca_msg_pending_notif_0_irq;
+	u8 ca_msg_pending_notif_1_irq;
+	void __iomem *intr_base;
+	void __iomem *ape_common_fifo_base;
+	void __iomem *ape_audio_fifo_base;
+	void __iomem *cmt_common_fifo_base;
+	void __iomem *cmt_audio_fifo_base;
+
+	u32 *ape_common_fifo_base_phy;
+	u32 *ape_audio_fifo_base_phy;
+	u32 *cmt_common_fifo_base_phy;
+	u32 *cmt_audio_fifo_base_phy;
+
+	int ape_common_fifo_size;
+	int ape_audio_fifo_size;
+	int cmt_common_fifo_size;
+	int cmt_audio_fifo_size;
+	int netdev_flag_up;
+	int msr_flag;
+
+	void __iomem *ac_common_shared_wptr;
+	void __iomem *ac_common_shared_rptr;
+	void __iomem *ca_common_shared_wptr;
+	void __iomem *ca_common_shared_rptr;
+
+	void __iomem *ac_audio_shared_wptr;
+	void __iomem *ac_audio_shared_rptr;
+	void __iomem *ca_audio_shared_wptr;
+	void __iomem *ca_audio_shared_rptr;
+
+	struct device *dev;
+	struct net_device *ndev;
+	struct isa_driver_context *isa_context;
+	struct workqueue_struct *shm_common_ch_wr_wq;
+	struct workqueue_struct *shm_audio_ch_wr_wq;
+	struct workqueue_struct *shm_ac_wake_wq;
+	struct workqueue_struct *shm_ca_wake_wq;
+	struct workqueue_struct *shm_ac_sleep_wq;
+	struct work_struct send_ac_msg_pend_notify_0;
+	struct work_struct send_ac_msg_pend_notify_1;
+	struct work_struct shm_ac_wake_req;
+	struct work_struct shm_ca_wake_req;
+	struct work_struct shm_ca_sleep_req;
+	struct work_struct shm_ac_sleep_req;
+};
+
+/**
+ * struct queue_element - information to add an element to queue
+ * @entry:	list entry
+ * @offset:	message offset
+ * @size:	message size
+ * @no:		total number of messages
+ */
+struct queue_element {
+	struct list_head entry;
+	u32 offset;
+	u32 size;
+	u32 no;
+};
+
+/**
+ * struct message_queue - ISI, RPC, AUDIO, SECURITY message queue information
+ * @fifo_base:		pointer to the respective fifo base
+ * @size:		size of the data to be read
+ * @readptr:		fifo read pointer
+ * @writeptr:		fifo write pointer
+ * @no:			total number of messages
+ * @update_lock:	spinlock for protecting the queue read operation
+ * @q_rp:		queue write pointer
+ * @wq_readable:	wait queue head
+ * @msg_list:		message list
+ * @shrm:		pointer to shrm device information structure
+ */
+struct message_queue {
+      u8 *fifo_base;
+      u32 size;
+      u32 readptr;
+      u32 writeptr;
+      u32 no;
+      spinlock_t update_lock;
+      atomic_t q_rp;
+      wait_queue_head_t wq_readable;
+      struct list_head msg_list;
+      struct shrm_dev *shrm;
+};
+
+/**
+ * struct isadev_context - shrm char interface context
+ * @dl_queue:	structre to store the queue related info
+ * @device_id:	message id(ISI, RPC, AUDIO, SECURITY)
+ */
+struct isadev_context {
+	struct message_queue dl_queue;
+	u8 device_id;
+	void *addr;
+};
+
+/**
+ * struct isa_driver_context - shrm char interface device information
+ * @is_open:		flag to check the usage of queue
+ * @isadev:		pointer to struct t_isadev_context
+ * @common_tx:		spinlock for protecting common channel
+ * @tx_audio_mutex:	mutex for protecting audio channel
+ * @cdev:		character device structre
+ * @shm_class:		pointer to the class structure
+ */
+struct isa_driver_context {
+	atomic_t is_open[ISA_DEVICES];
+	struct isadev_context *isadev;
+	spinlock_t common_tx;
+	struct mutex tx_audio_mutex;
+	struct cdev cdev;
+	struct class *shm_class;
+};
+
+#endif
diff --git a/arch/arm/mach-ux500/include/mach/shrm_net.h b/arch/arm/mach-ux500/include/mach/shrm_net.h
new file mode 100644
index 00000000000..4e675a98f3d
--- /dev/null
+++ b/arch/arm/mach-ux500/include/mach/shrm_net.h
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2009
+ *
+ * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef __SHRM_NET_H
+#define __SHRM_NET_H
+
+#define SHRM_HLEN 1
+#define PHONET_ALEN 1
+
+#define PN_PIPE		0xD9
+#define PN_DEV_HOST	0x00
+#define PN_LINK_ADDR	0x26
+#define PN_TX_QUEUE_LEN	3
+
+#define RESOURCE_ID_INDEX	3
+#define SRC_OBJ_INDEX		7
+#define MSG_ID_INDEX		9
+#define PIPE_HDL_INDEX		10
+#define NETLINK_SHRM            20
+
+/**
+ * struct shrm_net_iface_priv - shrm net interface device information
+ * @shrm_device:	pointer to the shrm device information structure
+ * @iface_num:		flag used to indicate the up/down of netdev
+ */
+struct shrm_net_iface_priv {
+	struct shrm_dev *shrm_device;
+	unsigned int iface_num;
+};
+
+int shrm_register_netdev(struct shrm_dev *shrm_dev_data);
+int shrm_net_receive(struct net_device *dev, unsigned char *data);
+int shrm_suspend_netdev(struct net_device *dev);
+int shrm_resume_netdev(struct net_device *dev);
+int shrm_stop_netdev(struct net_device *dev);
+int shrm_restart_netdev(struct net_device *dev);
+int shrm_start_netdev(struct net_device *dev);
+void shrm_unregister_netdev(struct shrm_dev *shrm_dev_data);
+
+#endif /* __SHRM_NET_H */
diff --git a/arch/arm/mach-ux500/include/mach/shrm_private.h b/arch/arm/mach-ux500/include/mach/shrm_private.h
new file mode 100644
index 00000000000..33a0e18234b
--- /dev/null
+++ b/arch/arm/mach-ux500/include/mach/shrm_private.h
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghavi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef __SHRM_PRIVATE_INCLUDED
+#define __SHRM_PRIVATE_INCLUDED
+
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <mach/shrm.h>
+
+#define GOP_OUTPUT_REGISTER_BASE (0x0)
+#define GOP_SET_REGISTER_BASE    (0x4)
+#define GOP_CLEAR_REGISTER_BASE  (0x8)
+#define GOP_TOGGLE_REGISTER_BASE (0xc)
+
+
+#define GOP_AUDIO_AC_READ_NOTIFICATION_BIT (0)
+#define GOP_AUDIO_CA_MSG_PENDING_NOTIFICATION_BIT (1)
+#define GOP_COMMON_AC_READ_NOTIFICATION_BIT (2)
+#define GOP_COMMON_CA_MSG_PENDING_NOTIFICATION_BIT (3)
+#define GOP_CA_WAKE_REQ_BIT (7)
+#define GOP_AUDIO_CA_READ_NOTIFICATION_BIT (23)
+#define GOP_AUDIO_AC_MSG_PENDING_NOTIFICATION_BIT (24)
+#define GOP_COMMON_CA_READ_NOTIFICATION_BIT (25)
+#define GOP_COMMON_AC_MSG_PENDING_NOTIFICATION_BIT (26)
+#define GOP_CA_WAKE_ACK_BIT (27)
+
+#define L2_MSG_MAPID_OFFSET (24)
+#define L1_MSG_MAPID_OFFSET (28)
+
+#define SHRM_SLEEP_STATE (0)
+#define SHRM_PTR_FREE (1)
+#define SHRM_PTR_BUSY (2)
+#define SHRM_IDLE (3)
+
+#define ISI_MESSAGING (0)
+#define RPC_MESSAGING (1)
+#define AUDIO_MESSAGING (2)
+#define SECURITY_MESSAGING (3)
+#define COMMON_LOOPBACK_MESSAGING (0xC0)
+#define AUDIO_LOOPBACK_MESSAGING (0x80)
+
+#define COMMON_CHANNEL		0
+#define AUDIO_CHANNEL		1
+
+typedef void (*MSG_PENDING_NOTIF)(const u32 Wptr);
+
+/**
+ * struct fifo_write_params - parameters used for FIFO write operation.
+ * @writer_local_rptr:	pointer to local read buffer
+ * @writer_local_wptr:	pointer to local write buffer
+ * @shared_wptr:	write pointer shared by cmt and ape
+ * @shared_rptr:	read pointer shared by cmt and ape
+ * @availablesize:	available memory in fifo
+ * @end_addr_fifo:	fifo end addr
+ * @fifo_virtual_addr:	fifo virtual addr
+ *
+ * On writting a message to FIFO the same has to be read by the modem before
+ * writing the next message to the FIFO. In oder to over come this a local
+ * write and read pointer is used for internal purpose.
+ */
+struct fifo_write_params {
+	u32 writer_local_rptr;
+	u32 writer_local_wptr;
+	u32 shared_wptr;
+	u32 shared_rptr;
+	u32 availablesize;
+	u32 end_addr_fifo;
+	u32 *fifo_virtual_addr;
+	spinlock_t fifo_update_lock;
+} ;
+
+/**
+ * struct fifo_read_params - parameters used for FIFO read operation
+ * @reader_local_rptr:	pointer to local read buffer
+ * @reader_local_wptr:	pointer to local write buffer
+ * @shared_wptr:	write pointer shared by cmt and ape
+ * @shared_rptr:	read pointer shared by cmt and ape
+ * @availablesize:	available memory in fifo
+ * @end_addr_fifo:	fifo end add
+ * @fifo_virtual_addr:	fifo virtual addr
+ */
+struct fifo_read_params{
+	u32 reader_local_rptr;
+	u32 reader_local_wptr;
+	u32 shared_wptr;
+	u32 shared_rptr;
+	u32 availablesize;
+	u32 end_addr_fifo;
+	u32 *fifo_virtual_addr;
+
+} ;
+
+int shrm_protocol_init(struct shrm_dev *shrm,
+			received_msg_handler common_rx_handler,
+			received_msg_handler audio_rx_handler);
+void shrm_protocol_deinit(struct shrm_dev *shrm);
+void shm_fifo_init(struct shrm_dev *shrm);
+int shm_write_msg_to_fifo(struct shrm_dev *shrm, u8 channel,
+				u8 l2header, void *addr, u32 length);
+int shm_write_msg(struct shrm_dev *shrm,
+			u8 l2_header, void *addr, u32 length);
+
+u8 is_the_only_one_unread_message(struct shrm_dev *shrm,
+						u8 channel, u32 length);
+u8 read_remaining_messages_common(void);
+u8 read_remaining_messages_audio(void);
+u8 read_one_l2msg_audio(struct shrm_dev *shrm,
+			u8 *p_l2_msg, u32 *p_len);
+u8 read_one_l2msg_common(struct shrm_dev *shrm,
+				u8 *p_l2_msg, u32 *p_len);
+void receive_messages_common(struct shrm_dev *shrm);
+void receive_messages_audio(struct shrm_dev *shrm);
+
+void update_ac_common_local_rptr(struct shrm_dev *shrm);
+void update_ac_audio_local_rptr(struct shrm_dev *shrm);
+void update_ca_common_local_wptr(struct shrm_dev *shrm);
+void update_ca_audio_local_wptr(struct shrm_dev *shrm);
+void update_ac_common_shared_wptr(struct shrm_dev *shrm);
+void update_ac_audio_shared_wptr(struct shrm_dev *shrm);
+void update_ca_common_shared_rptr(struct shrm_dev *shrm);
+void update_ca_audio_shared_rptr(struct shrm_dev *shrm);
+
+
+void get_writer_pointers(u8 msg_type, u32 *WriterLocalRptr, \
+			u32 *WriterLocalWptr, u32 *SharedWptr);
+void get_reader_pointers(u8 msg_type, u32 *ReaderLocalRptr, \
+			u32 *ReaderLocalWptr, u32 *SharedRptr);
+u8 read_boot_info_req(struct shrm_dev *shrm,
+				u32 *pConfig,
+				u32 *pVersion);
+void write_boot_info_resp(struct shrm_dev *shrm, u32 Config,
+							u32 Version);
+
+void send_ac_msg_pending_notification_0(struct shrm_dev *shrm);
+void send_ac_msg_pending_notification_1(struct shrm_dev *shrm);
+void ca_msg_read_notification_0(struct shrm_dev *shrm);
+void ca_msg_read_notification_1(struct shrm_dev *shrm);
+
+void set_ca_msg_0_read_notif_send(u8 val);
+u8 get_ca_msg_0_read_notif_send(void);
+void set_ca_msg_1_read_notif_send(u8 val);
+u8 get_ca_msg_1_read_notif_send(void);
+
+irqreturn_t ca_wake_irq_handler(int irq, void *ctrlr);
+irqreturn_t ac_read_notif_0_irq_handler(int irq, void *ctrlr);
+irqreturn_t ac_read_notif_1_irq_handler(int irq, void *ctrlr);
+irqreturn_t ca_msg_pending_notif_0_irq_handler(int irq, void *ctrlr);
+irqreturn_t ca_msg_pending_notif_1_irq_handler(int irq, void *ctrlr);
+
+void shm_ca_msgpending_0_tasklet(unsigned long);
+void shm_ca_msgpending_1_tasklet(unsigned long);
+void shm_ac_read_notif_0_tasklet(unsigned long);
+void shm_ac_read_notif_1_tasklet(unsigned long);
+void shm_ca_wake_req_tasklet(unsigned long);
+
+u8 get_boot_state(void);
+
+int get_ca_wake_req_state(void);
+
+/* shrm character interface */
+int isa_init(struct shrm_dev *shrm);
+void isa_exit(struct shrm_dev *shrm);
+int add_msg_to_queue(struct message_queue *q, u32 size);
+ssize_t isa_read(struct file *filp, char __user *buf, size_t len,
+							loff_t *ppos);
+int get_size_of_new_msg(struct message_queue *q);
+int remove_msg_from_queue(struct message_queue *q);
+void shrm_char_reset_queues(struct shrm_dev *shrm);
+int shrm_get_cdev_index(u8 l2_header);
+int shrm_get_cdev_l2header(u8 idx);
+
+#endif
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 0dc5d7ce486..bd155f091c4 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -49,6 +49,10 @@ obj-$(CONFIG_NSC_GPIO)		+= nsc_gpio.o
 obj-$(CONFIG_GPIO_TB0219)	+= tb0219.o
 obj-$(CONFIG_TELCLOCK)		+= tlclk.o
 
+ifdef CONFIG_PHONET
+obj-$(CONFIG_U8500_SHRM)	+= shrm_char.o
+endif
+
 obj-$(CONFIG_MWAVE)		+= mwave/
 obj-$(CONFIG_AGP)		+= agp/
 obj-$(CONFIG_PCMCIA)		+= pcmcia/
diff --git a/drivers/char/shrm_char.c b/drivers/char/shrm_char.c
new file mode 100644
index 00000000000..256add7cdb8
--- /dev/null
+++ b/drivers/char/shrm_char.c
@@ -0,0 +1,858 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghavi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+
+#include <mach/isa_ioctl.h>
+#include <mach/shrm_driver.h>
+#include <mach/shrm_private.h>
+#include <mach/shrm_config.h>
+#include <mach/shrm.h>
+
+
+#define NAME "IPC_ISA"
+/* L2 header for common loopback device is 0xc0 and hence 0xc0+1 = 193*/
+#define MAX_L2_HEADERS 193
+
+#define SIZE_OF_FIFO (512*1024)
+
+static u8 message_fifo[ISA_DEVICES][SIZE_OF_FIFO];
+
+static u8 wr_rpc_msg[10*1024];
+static u8 wr_sec_msg[10*1024];
+static u8 wr_audio_msg[10*1024];
+
+struct map_device {
+	u8 l2_header;
+	u8 idx;
+	char *name;
+};
+
+static struct map_device map_dev[] = {
+	{ISI_MESSAGING, 0, "isi"},
+	{RPC_MESSAGING, 1, "rpc"},
+	{AUDIO_MESSAGING, 2, "modemaudio"},
+	{SECURITY_MESSAGING, 3, "sec"},
+	{COMMON_LOOPBACK_MESSAGING, 4, "common_loopback"},
+	{AUDIO_LOOPBACK_MESSAGING, 5, "audio_loopback"},
+};
+
+/*
+ * int major:This variable is exported to user as module_param to specify
+ * major number at load time
+ */
+static int major;
+module_param(major, int, 0);
+MODULE_PARM_DESC(major, "Major device number");
+/* global fops mutex */
+static DEFINE_MUTEX(isa_lock);
+
+/**
+ * shrm_get_cdev_index() - return the index mapped to l2 header
+ * @l2_header:	L2 header
+ *
+ * struct map_device maps the index(count) with the device L2 header.
+ * This function returns the index for the provided L2 header in case
+ * of success else -ve value.
+ */
+int shrm_get_cdev_index(u8 l2_header)
+{
+	u8 cnt;
+	for (cnt = 0; cnt < ISA_DEVICES; cnt++) {
+		if (map_dev[cnt].l2_header == l2_header)
+			return map_dev[cnt].idx;
+	}
+	return -EINVAL;
+}
+
+/**
+ * shrm_get_cdev_l2header() - return l2_header mapped to the index
+ * @idx:	index
+ *
+ * struct map_device maps the index(count) with the device L2 header.
+ * This function returns the L2 header for the given index in case
+ * of success else -ve value.
+ */
+int shrm_get_cdev_l2header(u8 idx)
+{
+	u8 cnt;
+	for (cnt = 0; cnt < ISA_DEVICES; cnt++) {
+		if (map_dev[cnt].idx == idx)
+			return map_dev[cnt].l2_header;
+	}
+	return -EINVAL;
+}
+
+void shrm_char_reset_queues(struct shrm_dev *shrm)
+{
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context;
+	struct queue_element *cur_msg = NULL;
+	struct list_head *cur_msg_ptr = NULL;
+	struct list_head *msg_ptr;
+	struct message_queue *q;
+	int no_dev;
+
+	dev_info(shrm->dev, "%s: Resetting char device queues\n", __func__);
+	isa_context = shrm->isa_context;
+	for (no_dev = 0 ; no_dev < ISA_DEVICES ; no_dev++) {
+		isadev = &isa_context->isadev[no_dev];
+		q = &isadev->dl_queue;
+
+		/* empty out the msg queue */
+		list_for_each_safe(cur_msg_ptr, msg_ptr, &q->msg_list) {
+			cur_msg = list_entry(cur_msg_ptr,
+					struct queue_element, entry);
+			list_del(cur_msg_ptr);
+			kfree(cur_msg);
+		}
+
+		/* reset the msg queue pointers */
+		q->size = SIZE_OF_FIFO;
+		q->readptr = 0;
+		q->writeptr = 0;
+		q->no = 0;
+
+		/* wake up the blocking read/select */
+		atomic_set(&q->q_rp, 1);
+		wake_up_interruptible(&q->wq_readable);
+	}
+}
+
+/**
+ * create_queue() - To create FIFO for Tx and Rx message buffering.
+ * @q:		message queue.
+ * @devicetype:	device type 0-isi,1-rpc,2-audio,3-security,
+ * 4-common_loopback, 5-audio_loopback.
+ * @shrm:	pointer to the shrm device information structure
+ *
+ * This function creates a FIFO buffer of n_bytes size using
+ * dma_alloc_coherent(). It also initializes all queue handling
+ * locks, queue management pointers. It also initializes message list
+ * which occupies this queue.
+ */
+static int create_queue(struct message_queue *q, u32 devicetype,
+						struct shrm_dev *shrm)
+{
+	q->fifo_base = (u8 *)&message_fifo[devicetype];
+	q->size = SIZE_OF_FIFO;
+	q->readptr = 0;
+	q->writeptr = 0;
+	q->no = 0;
+	q->shrm = shrm;
+	spin_lock_init(&q->update_lock);
+	INIT_LIST_HEAD(&q->msg_list);
+	init_waitqueue_head(&q->wq_readable);
+	atomic_set(&q->q_rp, 0);
+
+	return 0;
+}
+
+static void delete_queue(struct message_queue *q)
+{
+	q->size = 0;
+	q->readptr = 0;
+	q->writeptr = 0;
+}
+
+/**
+ * add_msg_to_queue() - Add a message inside queue
+ * @q:		message queue
+ * @size:	size in bytes
+ *
+ * This function tries to allocate n_bytes of size in FIFO q.
+ * It returns negative number when no memory can be allocated
+ * currently.
+ */
+int add_msg_to_queue(struct message_queue *q, u32 size)
+{
+	struct queue_element *new_msg = NULL;
+	struct shrm_dev *shrm = q->shrm;
+
+	dev_dbg(shrm->dev, "%s IN q->writeptr=%d\n", __func__, q->writeptr);
+	new_msg = kmalloc(sizeof(struct queue_element), GFP_ATOMIC);
+	if (new_msg == NULL) {
+		dev_err(shrm->dev, "unable to allocate memory\n");
+		return -ENOMEM;
+	}
+	new_msg->offset = q->writeptr;
+	new_msg->size = size;
+	new_msg->no = q->no++;
+
+	/* check for overflow condition */
+	if (q->readptr <= q->writeptr) {
+		if (((q->writeptr-q->readptr) + size) >= q->size) {
+			dev_err(shrm->dev, "Buffer overflow !!\n");
+			BUG_ON(((q->writeptr-q->readptr) + size) >= q->size);
+		}
+	} else {
+		if ((q->writeptr + size) >= q->readptr) {
+			dev_err(shrm->dev, "Buffer overflow !!\n");
+			BUG_ON((q->writeptr + size) >= q->readptr);
+		}
+	}
+	q->writeptr = (q->writeptr + size) % q->size;
+	if (list_empty(&q->msg_list)) {
+		list_add_tail(&new_msg->entry, &q->msg_list);
+		/* There can be 2 blocking calls read  and another select */
+		atomic_set(&q->q_rp, 1);
+		wake_up_interruptible(&q->wq_readable);
+	} else
+		list_add_tail(&new_msg->entry, &q->msg_list);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return 0;
+}
+
+/**
+ * remove_msg_from_queue() - To remove a message from the msg queue.
+ * @q:	message queue
+ *
+ * This function delets a message from the message list associated with message
+ * queue q and also updates read ptr.
+ * If the message list is empty, then, event is set to block the select and
+ * read calls of the paricular queue.
+ *
+ * The message list is FIFO style and message is always added to tail and
+ * removed from head.
+ */
+int remove_msg_from_queue(struct message_queue *q)
+{
+	struct queue_element *old_msg = NULL;
+	struct shrm_dev *shrm = q->shrm;
+	struct list_head *msg;
+
+	dev_dbg(shrm->dev, "%s IN q->readptr %d\n", __func__, q->readptr);
+
+	list_for_each(msg, &q->msg_list) {
+		old_msg = list_entry(msg, struct queue_element, entry);
+		if (old_msg == NULL) {
+			dev_err(shrm->dev, "no message found\n");
+			return -EFAULT;
+		}
+		break;
+	}
+	list_del(msg);
+	q->readptr = (q->readptr + old_msg->size)%q->size;
+	if (list_empty(&q->msg_list)) {
+		dev_dbg(shrm->dev, "List is empty setting RP= 0\n");
+		atomic_set(&q->q_rp, 0);
+	}
+	kfree(old_msg);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return 0;
+}
+
+/**
+ * get_size_of_new_msg() - retrieve new message from message list
+ * @q:	message queue
+ *
+ * This function will retrieve most recent message from the corresponding
+ * queue list. New message is always retrieved from head side.
+ * It returns new message no, offset if FIFO and size.
+ */
+int get_size_of_new_msg(struct message_queue *q)
+{
+	struct queue_element *new_msg = NULL;
+	struct list_head *msg_list;
+	struct shrm_dev *shrm = q->shrm;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	spin_lock_bh(&q->update_lock);
+	list_for_each(msg_list, &q->msg_list) {
+		new_msg = list_entry(msg_list, struct queue_element, entry);
+		if (new_msg == NULL) {
+			spin_unlock_bh(&q->update_lock);
+			dev_err(shrm->dev, "no message found\n");
+			return -EFAULT;
+		}
+		break;
+	}
+	spin_unlock_bh(&q->update_lock);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return new_msg->size;
+}
+
+/**
+ * isa_select() - shrm char interface driver select interface
+ * @filp:	file descriptor pointer
+ * @wait:	poll_table_struct pointer
+ *
+ * This function is used to perform non-blocking read operations. It allows
+ * a process to determine whether it can read from one or more open files
+ * without blocking. These calls can also block a process until any of a
+ * given set of file descriptors becomes available for reading.
+ * If a file is ready to read, POLLIN | POLLRDNORM bitmask is returned.
+ * The driver method is called whenever the user-space program performs a select
+ * system call involving a file descriptor associated with the driver.
+ */
+static u32 isa_select(struct file *filp,
+				struct poll_table_struct *wait)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct message_queue *q;
+	u32 mask = 0;
+	u32 m = iminor(filp->f_path.dentry->d_inode);
+	u8 idx = shrm_get_cdev_index(m);
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (shrm->msr_flag)
+		return -ENODEV;
+
+	if (isadev->device_id != idx)
+			return -1;
+
+	q = &isadev->dl_queue;
+	poll_wait(filp, &q->wq_readable, wait);
+	if (atomic_read(&q->q_rp) == 1)
+		mask = POLLIN | POLLRDNORM;
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return mask;
+}
+
+/**
+ * isa_read() - Read from device
+ * @filp:	file descriptor
+ * @buf:	user buffer pointer
+ * @len:	size of requested data transfer
+ * @ppos:	not used
+ *
+ * It reads a oldest message from queue and copies it into user buffer and
+ * returns its size.
+ * If there is no message present in queue, then it blocks until new data is
+ * available.
+ */
+ssize_t isa_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
+{
+	u32 size = 0;
+	int ret;
+	char *psrc;
+	struct isadev_context *isadev = (struct isadev_context *)
+							filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct message_queue *q;
+	u32 msgsize;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (len <= 0)
+		return -EFAULT;
+
+	q = &isadev->dl_queue;
+
+	if (shrm->msr_flag) {
+		atomic_set(&q->q_rp, 0);
+		return -ENODEV;
+	}
+
+	spin_lock_bh(&q->update_lock);
+	if (list_empty(&q->msg_list)) {
+		spin_unlock_bh(&q->update_lock);
+		dev_dbg(shrm->dev, "Waiting for Data\n");
+		if (wait_event_interruptible(q->wq_readable,
+				atomic_read(&q->q_rp) == 1))
+			return -ERESTARTSYS;
+	} else
+		spin_unlock_bh(&q->update_lock);
+
+	if (shrm->msr_flag) {
+		atomic_set(&q->q_rp, 0);
+		return -ENODEV;
+	}
+
+	msgsize = get_size_of_new_msg(q);
+
+	if (len < msgsize)
+		return -EINVAL;
+
+	if ((q->readptr+msgsize) >= q->size) {
+		dev_dbg(shrm->dev, "Inside Loop Back\n");
+		psrc = (char *)buf;
+		size = (q->size-q->readptr);
+		/* Copy First Part of msg */
+		if (copy_to_user(psrc,
+				(u8 *)(q->fifo_base+q->readptr),
+				size)) {
+			dev_err(shrm->dev, "copy_to_user failed\n");
+			return -EFAULT;
+		}
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		if (copy_to_user(psrc,
+				(u8 *)(q->fifo_base),
+				(msgsize-size))) {
+			dev_err(shrm->dev, "copy_to_user failed\n");
+			return -EFAULT;
+		}
+	} else {
+		if (copy_to_user(buf,
+				(u8 *)(q->fifo_base + q->readptr),
+				msgsize)) {
+			dev_err(shrm->dev, "copy_to_user failed\n");
+			return -EFAULT;
+		}
+	}
+	spin_lock_bh(&q->update_lock);
+	ret = remove_msg_from_queue(q);
+	if (ret < 0) {
+		dev_err(shrm->dev,
+				"Remove msg from message queue failed\n");
+		msgsize = ret;
+	}
+	spin_unlock_bh(&q->update_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return msgsize;
+}
+
+/**
+ * isa_write() - Write to shrm char device
+ * @filp:	file descriptor
+ * @buf:	user buffer pointer
+ * @len:	size of requested data transfer
+ * @ppos:	not used
+ *
+ * It checks if there is space available in queue, and copies the message
+ * inside queue. If there is no space, it blocks until space becomes available.
+ * It also schedules transfer thread to transmit the newly added message.
+ */
+ssize_t isa_write(struct file *filp, const char __user *buf,
+				 size_t len, loff_t *ppos)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct message_queue *q;
+	void *addr = 0;
+	int err, l2_header;
+	int ret = 0;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (len <= 0 || buf == NULL)
+		return -EFAULT;
+	q = &isadev->dl_queue;
+	l2_header = shrm_get_cdev_l2header(isadev->device_id);
+	if (l2_header < 0) {
+		dev_err(shrm->dev, "failed to get L2 header\n");
+		return l2_header;
+	}
+
+	switch (l2_header) {
+	case RPC_MESSAGING:
+		dev_dbg(shrm->dev, "RPC\n");
+		addr = (void *)wr_rpc_msg;
+		break;
+	case AUDIO_MESSAGING:
+		dev_dbg(shrm->dev, "Audio\n");
+		addr = (void *)wr_audio_msg;
+		break;
+	case SECURITY_MESSAGING:
+		dev_dbg(shrm->dev, "Security\n");
+		addr = (void *)wr_sec_msg;
+		break;
+	case COMMON_LOOPBACK_MESSAGING:
+		dev_dbg(shrm->dev, "Common loopback\n");
+		addr = isadev->addr;
+		break;
+	case AUDIO_LOOPBACK_MESSAGING:
+		dev_dbg(shrm->dev, "Audio loopback\n");
+		addr = isadev->addr;
+		break;
+	default:
+		dev_dbg(shrm->dev, "Wrong device\n");
+		return -EFAULT;
+	}
+
+	if (copy_from_user(addr, buf, len)) {
+		dev_err(shrm->dev, "copy_from_user failed\n");
+		return -EFAULT;
+	}
+	/* Write msg to Fifo */
+	if ((l2_header == AUDIO_MESSAGING) ||
+			(l2_header == AUDIO_LOOPBACK_MESSAGING)) {
+		mutex_lock(&shrm->isa_context->tx_audio_mutex);
+		err = shm_write_msg(shrm, l2_header, addr, len);
+		if (!err)
+			ret = len;
+		else
+			ret = err;
+		mutex_unlock(&shrm->isa_context->tx_audio_mutex);
+	} else {
+		spin_lock_bh(&shrm->isa_context->common_tx);
+		err = shm_write_msg(shrm, l2_header, addr, len);
+		if (!err)
+			ret = len;
+		else
+			ret = err;
+		spin_unlock_bh(&shrm->isa_context->common_tx);
+	}
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * isa_ioctl() - To handle different ioctl commands supported by driver.
+ * @inode:	structure is used by the kernel internally to represent files
+ * @filp:	file descriptor pointer
+ * @cmd:	ioctl command
+ * @arg:	input param
+ *
+ * Following ioctls are supported by this driver.
+ * DLP_IOCTL_ALLOCATE_BUFFER - To allocate buffer for new uplink message.
+ * This ioctl is called with required message size. It returns offset for
+ * the allocates space in the queue. DLP_IOCTL_PUT_MESSAGE -  To indicate
+ * new uplink message available in queuq for  transmission. Message is copied
+ * from offset location returned by previous ioctl before calling this ioctl.
+ * DLP_IOCTL_GET_MESSAGE - To check if any downlink message is available in
+ * queue. It returns  offset for new message inside queue.
+ * DLP_IOCTL_DEALLOCATE_BUFFER - To deallocate any buffer allocate for
+ * downlink message once the message is copied. Message is copied from offset
+ * location returned by previous ioctl before calling this ioctl.
+ */
+static int isa_ioctl(struct inode *inode, struct file *filp,
+				unsigned cmd, unsigned long arg)
+{
+	int err = 0;
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	u32 m = iminor(inode);
+
+	isadev = (struct isadev_context *)filp->private_data;
+
+	if (isadev->device_id != m)
+		return -EINVAL;
+
+	switch (cmd) {
+	case DLP_IOC_ALLOCATE_BUFFER:
+		dev_dbg(shrm->dev, "DLP_IOC_ALLOCATE_BUFFER\n");
+		break;
+	case DLP_IOC_PUT_MESSAGE:
+		dev_dbg(shrm->dev, "DLP_IOC_PUT_MESSAGE\n");
+		break;
+	case DLP_IOC_GET_MESSAGE:
+		dev_dbg(shrm->dev, "DLP_IOC_GET_MESSAGE\n");
+		break;
+	case DLP_IOC_DEALLOCATE_BUFFER:
+		dev_dbg(shrm->dev, "DLP_IOC_DEALLOCATE_BUFFER\n");
+		break;
+	default:
+		dev_dbg(shrm->dev, "Unknown IOCTL\n");
+		err = -EFAULT;
+		break;
+	}
+	return err;
+}
+/**
+ * isa_mmap() - Maps kernel queue memory to user space.
+ * @filp:	file descriptor pointer
+ * @vma:	virtual area memory structure.
+ *
+ * This function maps kernel FIFO into user space. This function
+ * shall be called twice to map both uplink and downlink buffers.
+ */
+static int isa_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+
+	u32 m = iminor(filp->f_path.dentry->d_inode);
+	dev_dbg(shrm->dev, "%s %d\n", __func__, m);
+
+	return 0;
+}
+
+/**
+ * isa_close() - Close device file
+ * @inode:	structure is used by the kernel internally to represent files
+ * @filp:	device file descriptor
+ *
+ * This function deletes structues associated with this file, deletes
+ * queues, flushes and destroys workqueus and closes this file.
+ * It also unregisters itself from l2mux driver.
+ */
+static int isa_close(struct inode *inode, struct file *filp)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct isa_driver_context *isa_context = shrm->isa_context;
+	u8 m;
+	int idx;
+
+	mutex_lock(&isa_lock);
+	m = iminor(filp->f_path.dentry->d_inode);
+	idx = shrm_get_cdev_index(m);
+	if (idx < 0) {
+		dev_err(shrm->dev, "failed to get index\n");
+		return idx;
+	}
+	dev_dbg(shrm->dev, "isa_close %d", m);
+
+	if (atomic_dec_and_test(&isa_context->is_open[idx])) {
+		atomic_inc(&isa_context->is_open[idx]);
+		dev_err(shrm->dev, "Device not opened yet\n");
+		mutex_unlock(&isa_lock);
+		return -ENODEV;
+	}
+	atomic_set(&isa_context->is_open[idx], 1);
+
+	switch (m) {
+	case RPC_MESSAGING:
+		dev_info(shrm->dev, "Close RPC_MESSAGING Device\n");
+		break;
+	case AUDIO_MESSAGING:
+		dev_info(shrm->dev, "Close AUDIO_MESSAGING Device\n");
+		break;
+	case SECURITY_MESSAGING:
+		dev_info(shrm->dev, "CLose SECURITY_MESSAGING Device\n");
+		break;
+	case COMMON_LOOPBACK_MESSAGING:
+		kfree(isadev->addr);
+		dev_info(shrm->dev, "Close COMMON_LOOPBACK_MESSAGING Device\n");
+		break;
+	case AUDIO_LOOPBACK_MESSAGING:
+		kfree(isadev->addr);
+		dev_info(shrm->dev, "Close AUDIO_LOOPBACK_MESSAGING Device\n");
+		break;
+	default:
+		dev_info(shrm->dev, "No such device present\n");
+		mutex_unlock(&isa_lock);
+		return -ENODEV;
+	};
+	mutex_unlock(&isa_lock);
+	return 0;
+}
+/**
+ * isa_open() -  Open device file
+ * @inode:	structure is used by the kernel internally to represent files
+ * @filp:	device file descriptor
+ *
+ * This function performs initialization tasks needed to open SHM channel.
+ * Following tasks are performed.
+ * -return if device is already opened
+ * -create uplink FIFO
+ * -create downlink FIFO
+ * -init delayed workqueue thread
+ * -register to l2mux driver
+ */
+static int isa_open(struct inode *inode, struct file *filp)
+{
+	int err = 0;
+	u8 m;
+	int idx;
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context = container_of(
+						inode->i_cdev,
+						struct isa_driver_context,
+						cdev);
+	struct shrm_dev *shrm = isa_context->isadev->dl_queue.shrm;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (get_boot_state() != BOOT_DONE) {
+		dev_err(shrm->dev, "Boot is not done\n");
+		return -EBUSY;
+	}
+	mutex_lock(&isa_lock);
+	m = iminor(inode);
+
+	if ((m != RPC_MESSAGING) &&
+				(m != AUDIO_LOOPBACK_MESSAGING) &&
+				(m != COMMON_LOOPBACK_MESSAGING) &&
+				(m != AUDIO_MESSAGING) &&
+				(m != SECURITY_MESSAGING)) {
+		dev_err(shrm->dev, "No such device present\n");
+		mutex_unlock(&isa_lock);
+		return -ENODEV;
+	}
+	idx = shrm_get_cdev_index(m);
+	if (idx < 0) {
+		dev_err(shrm->dev, "failed to get index\n");
+		return idx;
+	}
+	if (!atomic_dec_and_test(&isa_context->is_open[idx])) {
+		atomic_inc(&isa_context->is_open[idx]);
+		dev_err(shrm->dev, "Device already opened\n");
+		mutex_unlock(&isa_lock);
+		return -EBUSY;
+	}
+	isadev = &isa_context->isadev[idx];
+	if (filp != NULL)
+		filp->private_data = isadev;
+
+	switch (m) {
+	case RPC_MESSAGING:
+		dev_info(shrm->dev, "Open RPC_MESSAGING Device\n");
+		break;
+	case AUDIO_MESSAGING:
+		dev_info(shrm->dev, "Open AUDIO_MESSAGING Device\n");
+		break;
+	case SECURITY_MESSAGING:
+		dev_info(shrm->dev, "Open SECURITY_MESSAGING Device\n");
+		break;
+	case COMMON_LOOPBACK_MESSAGING:
+		isadev->addr = kzalloc(10 * 1024, GFP_KERNEL);
+		if (!isadev->addr) {
+			mutex_unlock(&isa_lock);
+			return -ENOMEM;
+		}
+		dev_info(shrm->dev, "Open COMMON_LOOPBACK_MESSAGING Device\n");
+		break;
+	case AUDIO_LOOPBACK_MESSAGING:
+		isadev->addr = kzalloc(10 * 1024, GFP_KERNEL);
+		if (!isadev->addr) {
+			mutex_unlock(&isa_lock);
+			return -ENOMEM;
+		}
+		dev_info(shrm->dev, "Open AUDIO_LOOPBACK_MESSAGING Device\n");
+		break;
+	};
+
+	mutex_unlock(&isa_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return err;
+}
+
+const struct file_operations isa_fops = {
+	.owner = THIS_MODULE,
+	.open = isa_open,
+	.release = isa_close,
+	.ioctl = isa_ioctl,
+	.mmap = isa_mmap,
+	.read = isa_read,
+	.write = isa_write,
+	.poll = isa_select,
+};
+
+/**
+ * isa_init() - module insertion function
+ * @shrm:	pointer to the shrm device information structure
+ *
+ * This function registers module as a character driver using
+ * register_chrdev_region() or alloc_chrdev_region. It adds this
+ * driver to system using cdev_add() call. Major number is dynamically
+ * allocated using alloc_chrdev_region() by default or left to user to specify
+ * it during load time. For this variable major is used as module_param
+ * Nodes to be created using
+ * mknod /dev/isi c $major 0
+ * mknod /dev/rpc c $major 1
+ * mknod /dev/audio c $major 2
+ * mknod /dev/sec c $major 3
+ */
+int isa_init(struct shrm_dev *shrm)
+{
+	dev_t	dev_id;
+	int	retval, no_dev;
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context;
+
+	isa_context = kzalloc(sizeof(struct isa_driver_context),
+								GFP_KERNEL);
+	if (isa_context == NULL) {
+		dev_err(shrm->dev, "Failed to alloc memory\n");
+		return -ENOMEM;
+	}
+	shrm->isa_context = isa_context;
+	if (major) {
+		dev_id = MKDEV(major, MAX_L2_HEADERS);
+		retval = register_chrdev_region(dev_id, ISA_DEVICES, NAME);
+	} else {
+		/*
+		 * L2 header of loopback device is 192(0xc0). As per the shrm
+		 * protocol the minor id of the deivce is mapped to the
+		 * L2 header.
+		 */
+		retval = alloc_chrdev_region(&dev_id, 0, MAX_L2_HEADERS, NAME);
+		major = MAJOR(dev_id);
+	}
+	dev_dbg(shrm->dev, " major %d\n", major);
+
+	cdev_init(&isa_context->cdev, &isa_fops);
+	isa_context->cdev.owner = THIS_MODULE;
+	retval = cdev_add(&isa_context->cdev, dev_id, MAX_L2_HEADERS);
+	if (retval) {
+		dev_err(shrm->dev, "Failed to add char device\n");
+		return retval;
+	}
+	/* create class and device */
+	isa_context->shm_class = class_create(THIS_MODULE, NAME);
+	if (IS_ERR(isa_context->shm_class)) {
+		dev_err(shrm->dev, "Error creating shrm class\n");
+		cdev_del(&isa_context->cdev);
+		retval = PTR_ERR(isa_context->shm_class);
+		kfree(isa_context);
+		return retval;
+	}
+
+	for (no_dev = 0; no_dev < ISA_DEVICES; no_dev++) {
+		atomic_set(&isa_context->is_open[no_dev], 1);
+		device_create(isa_context->shm_class, NULL,
+				MKDEV(MAJOR(dev_id),
+				map_dev[no_dev].l2_header), NULL,
+				map_dev[no_dev].name);
+	}
+
+	isa_context->isadev = kzalloc(sizeof
+				(struct isadev_context)*ISA_DEVICES,
+				GFP_KERNEL);
+	if (isa_context->isadev == NULL) {
+		dev_err(shrm->dev, "Failed to alloc memory\n");
+		return -ENOMEM;
+	}
+	for (no_dev = 0 ; no_dev < ISA_DEVICES ; no_dev++) {
+		isadev = &isa_context->isadev[no_dev];
+		isadev->device_id = no_dev;
+		retval = create_queue(&isadev->dl_queue,
+					isadev->device_id, shrm);
+
+		if (retval < 0) {
+			dev_err(shrm->dev, "create dl_queue failed\n");
+			delete_queue(&isadev->dl_queue);
+			kfree(isadev);
+			return retval;
+		}
+	}
+	mutex_init(&isa_context->tx_audio_mutex);
+	spin_lock_init(&isa_context->common_tx);
+	dev_dbg(shrm->dev, " SHM Char Driver added\n");
+	return retval;
+}
+
+void isa_exit(struct shrm_dev *shrm)
+{
+	int no_dev;
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context = shrm->isa_context;
+	dev_t dev_id = MKDEV(major, 0);
+
+	for (no_dev = 0 ; no_dev < ISA_DEVICES ; no_dev++) {
+		device_destroy(isa_context->shm_class,
+				MKDEV(MAJOR(dev_id),
+				map_dev[no_dev].l2_header));
+		isadev = &isa_context->isadev[no_dev];
+		delete_queue(&isadev->dl_queue);
+		kfree(isadev);
+	}
+	class_destroy(isa_context->shm_class);
+	cdev_del(&isa_context->cdev);
+	unregister_chrdev_region(dev_id, ISA_DEVICES);
+	kfree(isa_context);
+	dev_dbg(shrm->dev, " SHM Char Driver removed\n");
+}
diff --git a/drivers/misc/shrm/Kconfig b/drivers/misc/shrm/Kconfig
new file mode 100644
index 00000000000..fffee1c703e
--- /dev/null
+++ b/drivers/misc/shrm/Kconfig
@@ -0,0 +1,49 @@
+#
+# SHM HW kernel configuration
+#
+config U8500_SHRM
+	tristate "U8500 SHRM hardware driver"
+	depends on ARCH_U8500 && PHONET
+	default Y
+	---help---
+	  If you say Y here, you will enable the STN8500 SHM hardware driver.
+
+	  If unsure, say N.
+choice
+	prompt "Modem Image Version"
+	depends on U8500_SHRM
+	default SHRM_V1_UPDATES_VERSION
+
+	config SHRM_ED_V1_VERSION
+	depends on U8500_SHRM
+	bool "SHRM ED / V1 "
+	help
+	 Modem Images with ED/V1 updates
+
+	config SHRM_V1_UPDATES_VERSION
+	depends on U8500_SHRM
+	bool "SHRM V1 UPDATES"
+	help
+	 Modem Images with V1 Updates
+
+endchoice
+
+config U8500_SHRM_LOOP_BACK
+	tristate "U8500 SHRM loopback"
+	depends on U8500_SHRM
+	default n
+	---help---
+	  If you say Y here, you will enable the shm loopback
+
+	  If unsure, say N.
+
+config U8500_SHRM_MODEM_SILENT_RESET
+	bool "U8500 SHRM Modem Silent Reset"
+	depends on U8500_SHRM
+	default n
+	---help---
+	  If you say Y here, you will enable the modem silent reset feature
+
+	  If unsure, say N.
+
+
diff --git a/drivers/misc/shrm/Makefile b/drivers/misc/shrm/Makefile
new file mode 100644
index 00000000000..8115c24920b
--- /dev/null
+++ b/drivers/misc/shrm/Makefile
@@ -0,0 +1,11 @@
+#
+# Makefile for SHRM drivers
+#
+
+ifdef CONFIG_PHONET
+u8500_shrm-objs := 	modem_shrm_driver.o shrm_fifo.o shrm_protocol.o
+else
+u8500_shrm-objs := 	shrm_driver.o shrm_fifo.o shrm_protocol.o
+endif
+
+obj-$(CONFIG_U8500_SHRM)	+= u8500_shrm.o
diff --git a/drivers/misc/shrm/modem_shrm_driver.c b/drivers/misc/shrm/modem_shrm_driver.c
new file mode 100644
index 00000000000..d94c007098b
--- /dev/null
+++ b/drivers/misc/shrm/modem_shrm_driver.c
@@ -0,0 +1,667 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/smp_lock.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <asm/atomic.h>
+#include <linux/io.h>
+
+#include <mach/isa_ioctl.h>
+#include <mach/shrm_driver.h>
+#include <mach/shrm_private.h>
+#include <mach/shrm_config.h>
+#include <mach/shrm_net.h>
+#include <mach/shrm.h>
+
+#include <linux/skbuff.h>
+#ifdef CONFIG_HIGH_RES_TIMERS
+#include <linux/hrtimer.h>
+static struct hrtimer timer;
+#endif
+#include <linux/if_ether.h>
+#include <linux/netdevice.h>
+#include <linux/phonet.h>
+
+/* debug functionality */
+#define ISA_DEBUG 0
+
+#define PHONET_TASKLET
+#define MAX_RCV_LEN	2048
+static u8 ph_recv_buf[MAX_RCV_LEN];
+
+void do_phonet_rcv_tasklet(unsigned long unused);
+struct tasklet_struct phonet_rcv_tasklet;
+
+/**
+ * audio_receive() - Receive audio channel completion callback
+ * @shrm:	pointer to shrm device information structure
+ * @data:	message pointer
+ * @n_bytes:	message size
+ * @l2_header:	L2 header/device ID 2->audio, 5->audio_loopback
+ *
+ * This fucntion is called from the audio receive handler. Copies the audio
+ * message from the FIFO to the AUDIO queue. The message is later copied from
+ * this queue to the user buffer through the char or net interface read
+ * operation.
+ */
+static int audio_receive(struct shrm_dev *shrm, void *data,
+					u32 n_bytes, u8 l2_header)
+{
+	u32 size = 0;
+	int ret = 0;
+	int idx;
+	u8 *psrc;
+	struct message_queue *q;
+	struct isadev_context *audiodev;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	idx = shrm_get_cdev_index(l2_header);
+	if (idx < 0) {
+		dev_err(shrm->dev, "failed to get index\n");
+		return idx;
+	}
+	audiodev = &shrm->isa_context->isadev[idx];
+	q = &audiodev->dl_queue;
+	spin_lock(&q->update_lock);
+	/* Memcopy RX data first */
+	if ((q->writeptr+n_bytes) >= q->size) {
+		psrc = (u8 *)data;
+		size = (q->size-q->writeptr);
+		/* Copy First Part of msg */
+		memcpy((q->fifo_base+q->writeptr), psrc, size);
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		memcpy(q->fifo_base, psrc, (n_bytes-size));
+	} else {
+		memcpy((q->fifo_base+q->writeptr), data, n_bytes);
+	}
+	ret = add_msg_to_queue(q, n_bytes);
+	spin_unlock(&q->update_lock);
+	if (ret < 0)
+		dev_err(shrm->dev, "Adding a msg to message queue failed");
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * common_receive() - Receive common channel completion callback
+ * @shrm:	pointer to the shrm device information structure
+ * @data:	message pointer
+ * @n_bytes:	message size
+ * @l2_header:	L2 header / device ID
+ *
+ * This function is called from the receive handler to copy the respective
+ * ISI, RPC, SECURITY message to its respective queue. The message is then
+ * copied from queue to the user buffer on char net interface read operation.
+ */
+static int common_receive(struct shrm_dev *shrm, void *data,
+					u32 n_bytes, u8 l2_header)
+{
+	u32 size = 0;
+	int ret = 0;
+	int idx;
+	u8 *psrc;
+	struct message_queue *q;
+	struct isadev_context *isa_dev;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	idx = shrm_get_cdev_index(l2_header);
+	if (idx < 0) {
+		dev_err(shrm->dev, "failed to get index\n");
+		return idx;
+	}
+	isa_dev = &shrm->isa_context->isadev[idx];
+	q = &isa_dev->dl_queue;
+	spin_lock(&q->update_lock);
+	/* Memcopy RX data first */
+	if ((q->writeptr+n_bytes) >= q->size) {
+		dev_dbg(shrm->dev, "Inside Loop Back\n");
+		psrc = (u8 *)data;
+		size = (q->size-q->writeptr);
+		/* Copy First Part of msg */
+		memcpy((q->fifo_base+q->writeptr), psrc, size);
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		memcpy(q->fifo_base, psrc, (n_bytes-size));
+	} else {
+		memcpy((q->fifo_base+q->writeptr), data, n_bytes);
+	}
+	ret = add_msg_to_queue(q, n_bytes);
+	spin_unlock(&q->update_lock);
+	if (ret < 0) {
+		dev_err(shrm->dev, "Adding a msg to message queue failed");
+		return ret;
+	}
+
+
+	if (l2_header == ISI_MESSAGING) {
+		if (shrm->netdev_flag_up) {
+			dev_dbg(shrm->dev,
+				"scheduling the phonet tasklet from %s!\n",
+				__func__);
+			tasklet_schedule(&phonet_rcv_tasklet);
+		}
+		dev_dbg(shrm->dev,
+				"Out of phonet tasklet %s!!!\n", __func__);
+	}
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * rx_common_l2msg_handler() - common channel receive handler
+ * @l2_header:		L2 header
+ * @msg:		pointer to the receive buffer
+ * @length:		length of the msg to read
+ * @shrm:		pointer to shrm device information structure
+ *
+ * This function is called to receive the message from CaMsgPendingNotification
+ * interrupt handler.
+ */
+static void rx_common_l2msg_handler(u8 l2_header,
+				 void *msg, u32 length,
+				 struct shrm_dev *shrm)
+{
+	int ret = 0;
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	ret = common_receive(shrm, msg, length, l2_header);
+	if (ret < 0)
+		dev_err(shrm->dev,
+			"common receive with l2 header %d failed\n", l2_header);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+/**
+ * rx_audio_l2msg_handler() - audio channel receive handler
+ * @l2_header:		L2 header
+ * @msg:		pointer to the receive buffer
+ * @length:		length of the msg to read
+ * @shrm:		pointer to shrm device information structure
+ *
+ * This function is called to receive the message from CaMsgPendingNotification
+ * interrupt handler.
+ */
+static void rx_audio_l2msg_handler(u8 l2_header,
+				void *msg, u32 length,
+				struct shrm_dev *shrm)
+{
+	int ret = 0;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	ret = audio_receive(shrm, msg, length, l2_header);
+	if (ret < 0)
+		dev_err(shrm->dev, "audio receive failed\n");
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+static int __init shm_initialise_irq(struct shrm_dev *shrm)
+{
+	int err = 0;
+
+	err  = shrm_protocol_init(shrm,
+			rx_common_l2msg_handler, rx_audio_l2msg_handler);
+	if (err < 0) {
+		dev_err(shrm->dev, "SHM Protocol Init Failure\n");
+		return err;
+	}
+
+	err = request_irq(shrm->ca_wake_irq,
+			ca_wake_irq_handler, IRQF_TRIGGER_RISING,
+				 "ca_wake-up", shrm);
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"Unable to allocate shm tx interrupt line\n");
+		free_irq(shrm->ca_wake_irq, shrm);
+		return err;
+	}
+
+	err = request_irq(shrm->ac_read_notif_0_irq,
+		ac_read_notif_0_irq_handler, 0,
+		"ac_read_notif_0", shrm);
+
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"error ac_read_notif_0_irq interrupt line\n");
+		goto irq_err1;
+	}
+
+	err = request_irq(shrm->ac_read_notif_1_irq,
+		ac_read_notif_1_irq_handler, 0,
+		"ac_read_notif_1", shrm);
+
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"error ac_read_notif_1_irq interrupt line\n");
+		goto irq_err2;
+	}
+
+	err = request_irq(shrm->ca_msg_pending_notif_0_irq,
+		 ca_msg_pending_notif_0_irq_handler, 0,
+		"ca_msg_pending_notif_0", shrm);
+
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"error ca_msg_pending_notif_0_irq line\n");
+		goto irq_err3;
+	}
+
+	err = request_irq(shrm->ca_msg_pending_notif_1_irq,
+		 ca_msg_pending_notif_1_irq_handler, 0,
+		"ca_msg_pending_notif_1", shrm);
+
+	if (err < 0) {
+		dev_err(shrm->dev,
+			"error ca_msg_pending_notif_1_irq interrupt line\n");
+		goto irq_err4;
+	}
+	return err;
+irq_err4:
+	free_irq(shrm->ca_msg_pending_notif_0_irq, shrm);
+irq_err3:
+	free_irq(shrm->ac_read_notif_1_irq, shrm);
+irq_err2:
+	free_irq(shrm->ac_read_notif_0_irq, shrm);
+irq_err1:
+	free_irq(shrm->ca_wake_irq, shrm);
+	return err;
+}
+
+static void free_shm_irq(struct shrm_dev *shrm)
+{
+	free_irq(shrm->ca_wake_irq, shrm);
+	free_irq(shrm->ac_read_notif_0_irq, shrm);
+	free_irq(shrm->ac_read_notif_1_irq, shrm);
+	free_irq(shrm->ca_msg_pending_notif_0_irq, shrm);
+	free_irq(shrm->ca_msg_pending_notif_1_irq, shrm);
+}
+
+
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+static enum hrtimer_restart callback(struct hrtimer *timer)
+{
+	return HRTIMER_NORESTART;
+}
+#endif
+
+void do_phonet_rcv_tasklet(unsigned long unused)
+{
+	ssize_t ret;
+	struct shrm_dev *shrm = (struct shrm_dev *)unused;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	for (;;) {
+		ret = shrm_net_receive(shrm->ndev, ph_recv_buf);
+		if (ret == 0) {
+			dev_dbg(shrm->dev, "len is zero, queue empty\n");
+			break;
+		}
+		if (ret < 0) {
+			dev_err(shrm->dev, "len < 0 !!! error!!!\n");
+			break;
+		}
+	}
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+static int shrm_probe(struct platform_device *pdev)
+{
+	int err = 0;
+	struct resource *res;
+	struct shrm_dev *shrm = NULL;
+
+	shrm = kzalloc(sizeof(struct shrm_dev), GFP_KERNEL);
+	if (shrm == NULL) {
+		dev_err(&pdev->dev,
+			"Could not allocate memory for struct shm_dev\n");
+		return -ENOMEM;
+	}
+
+	shrm->dev = &pdev->dev;
+	/* initialise the SHM */
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(shrm->dev,
+				"Unable to map Ca Wake up interrupt\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ca_wake_irq = res->start;
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map APE_Read_notif_common IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ac_read_notif_0_irq = res->start;
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 2);
+
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map APE_Read_notif_audio IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ac_read_notif_1_irq = res->start;
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 3);
+
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map Cmt_msg_pending_notif_common IRQbase\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ca_msg_pending_notif_0_irq = res->start;
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 4);
+
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map Cmt_msg_pending_notif_audio IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ca_msg_pending_notif_1_irq = res->start;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!res) {
+		dev_err(shrm->dev,
+				"Could not get SHM IO memory information\n");
+		err = -ENODEV;
+		goto rollback_intr;
+	}
+	shrm->intr_base = (void __iomem *)ioremap_nocache(res->start,
+					res->end - res->start + 1);
+	if (!(shrm->intr_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ape_common_fifo_base_phy =
+			(u32 *)U8500_SHM_FIFO_APE_COMMON_BASE;
+	shrm->ape_common_fifo_base =
+		(void __iomem *)ioremap_nocache(
+					U8500_SHM_FIFO_APE_COMMON_BASE,
+					SHM_FIFO_0_SIZE);
+	shrm->ape_common_fifo_size = (SHM_FIFO_0_SIZE)/4;
+
+	if (!(shrm->ape_common_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_ape_common_fifo_base;
+	}
+	shrm->cmt_common_fifo_base_phy =
+		(u32 *)U8500_SHM_FIFO_CMT_COMMON_BASE;
+	shrm->cmt_common_fifo_base =
+		(void __iomem *)ioremap_nocache(
+			U8500_SHM_FIFO_CMT_COMMON_BASE, SHM_FIFO_0_SIZE);
+	shrm->cmt_common_fifo_size = (SHM_FIFO_0_SIZE)/4;
+
+	if (!(shrm->cmt_common_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_cmt_common_fifo_base;
+	}
+	shrm->ape_audio_fifo_base_phy =
+			(u32 *)U8500_SHM_FIFO_APE_AUDIO_BASE;
+	shrm->ape_audio_fifo_base =
+		(void __iomem *)ioremap_nocache(U8500_SHM_FIFO_APE_AUDIO_BASE,
+							SHM_FIFO_1_SIZE);
+	shrm->ape_audio_fifo_size = (SHM_FIFO_1_SIZE)/4;
+
+	if (!(shrm->ape_audio_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_ape_audio_fifo_base;
+	}
+	shrm->cmt_audio_fifo_base_phy =
+			(u32 *)U8500_SHM_FIFO_CMT_AUDIO_BASE;
+	shrm->cmt_audio_fifo_base =
+		(void __iomem *)ioremap_nocache(U8500_SHM_FIFO_CMT_AUDIO_BASE,
+							SHM_FIFO_1_SIZE);
+	shrm->cmt_audio_fifo_size = (SHM_FIFO_1_SIZE)/4;
+
+	if (!(shrm->cmt_audio_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_cmt_audio_fifo_base;
+	}
+	shrm->ac_common_shared_wptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_0_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_common_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_ac_common_shared_wptr;
+	}
+	shrm->ac_common_shared_rptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_0_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_common_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+	shrm->ca_common_shared_wptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_0_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_common_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+	shrm->ca_common_shared_rptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_0_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_common_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+	shrm->ac_audio_shared_wptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_1_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_audio_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+	shrm->ac_audio_shared_rptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_1_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_audio_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+	shrm->ca_audio_shared_wptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_1_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_audio_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+	shrm->ca_audio_shared_rptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_1_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_audio_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+	if (isa_init(shrm) != 0) {
+		dev_err(shrm->dev, "Driver Initialization Error\n");
+		err = -EBUSY;
+	}
+	/* install handlers and tasklets */
+	if (shm_initialise_irq(shrm)) {
+		dev_err(shrm->dev,
+				"shm error in interrupt registration\n");
+		goto rollback_irq;
+	}
+#ifdef CONFIG_HIGH_RES_TIMERS
+	hrtimer_init(&timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	timer.function = callback;
+	hrtimer_start(&timer, ktime_set(0, 2*NSEC_PER_MSEC), HRTIMER_MODE_REL);
+#endif
+	err = shrm_register_netdev(shrm);
+	if (err < 0)
+		goto rollback_irq;
+
+	tasklet_init(&phonet_rcv_tasklet, do_phonet_rcv_tasklet, 0);
+	phonet_rcv_tasklet.data = (unsigned long)shrm;
+
+	platform_set_drvdata(pdev, shrm);
+
+	return err;
+rollback_irq:
+	free_shm_irq(shrm);
+rollback_map:
+	iounmap(shrm->ac_common_shared_wptr);
+	iounmap(shrm->ac_common_shared_rptr);
+	iounmap(shrm->ca_common_shared_wptr);
+	iounmap(shrm->ca_common_shared_rptr);
+	iounmap(shrm->ac_audio_shared_wptr);
+	iounmap(shrm->ac_audio_shared_rptr);
+	iounmap(shrm->ca_audio_shared_wptr);
+	iounmap(shrm->ca_audio_shared_rptr);
+rollback_ac_common_shared_wptr:
+	iounmap(shrm->cmt_audio_fifo_base);
+rollback_cmt_audio_fifo_base:
+	iounmap(shrm->ape_audio_fifo_base);
+rollback_ape_audio_fifo_base:
+	iounmap(shrm->cmt_common_fifo_base);
+rollback_cmt_common_fifo_base:
+	iounmap(shrm->ape_common_fifo_base);
+rollback_ape_common_fifo_base:
+	iounmap(shrm->intr_base);
+rollback_intr:
+	kfree(shrm);
+	return err;
+}
+
+static int __exit shrm_remove(struct platform_device *pdev)
+{
+	struct shrm_dev *shrm = platform_get_drvdata(pdev);
+
+	free_shm_irq(shrm);
+	iounmap(shrm->intr_base);
+	iounmap(shrm->ape_common_fifo_base);
+	iounmap(shrm->cmt_common_fifo_base);
+	iounmap(shrm->ape_audio_fifo_base);
+	iounmap(shrm->cmt_audio_fifo_base);
+	iounmap(shrm->ac_common_shared_wptr);
+	iounmap(shrm->ac_common_shared_rptr);
+	iounmap(shrm->ca_common_shared_wptr);
+	iounmap(shrm->ca_common_shared_rptr);
+	iounmap(shrm->ac_audio_shared_wptr);
+	iounmap(shrm->ac_audio_shared_rptr);
+	iounmap(shrm->ca_audio_shared_wptr);
+	iounmap(shrm->ca_audio_shared_rptr);
+	shrm_unregister_netdev(shrm);
+	isa_exit(shrm);
+	kfree(shrm);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+/**
+ * u8500_shrm_suspend() - This routine puts the SHRM in to sustend state.
+ * @dev:	pointer to device structure.
+ *
+ * This routine checks the current ongoing communication with Modem by
+ * examining the ca_wake state and prevents suspend if modem communication
+ * is on-going.
+ * If ca_wake = 1 (high), modem comm. is on-going; don't suspend
+ * If ca_wake = 0 (low), no comm. with modem on-going.Allow suspend
+ */
+int u8500_shrm_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct shrm_dev *shrm = platform_get_drvdata(pdev);
+	int err;
+
+	dev_dbg(&pdev->dev, "%s called...\n", __func__);
+	dev_dbg(&pdev->dev, "ca_wake_req_state = %x\n",
+						get_ca_wake_req_state());
+
+	/* if ca_wake_req is high, prevent system suspend */
+	if (!get_ca_wake_req_state()) {
+		err = shrm_suspend_netdev(shrm->ndev);
+		return err;
+	} else
+		return -EBUSY;
+}
+
+/**
+ * u8500_shrm_resume() - This routine resumes the SHRM from suspend state.
+ * @dev:	pointer to device structure
+ *
+ * This routine restore back the current state of the SHRM
+ */
+int u8500_shrm_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct shrm_dev *shrm = platform_get_drvdata(pdev);
+	int err;
+
+	dev_dbg(&pdev->dev, "%s called...\n", __func__);
+	err = shrm_resume_netdev(shrm->ndev);
+
+	return err;
+}
+
+static const struct dev_pm_ops shrm_dev_pm_ops = {
+	.suspend_noirq = u8500_shrm_suspend,
+	.resume_noirq = u8500_shrm_resume,
+};
+#endif
+
+static struct platform_driver shrm_driver = {
+	.remove = __exit_p(shrm_remove),
+	.driver = {
+		.name = "u8500_shrm",
+		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm = &shrm_dev_pm_ops,
+#endif
+	},
+};
+
+static int __init shrm_driver_init(void)
+{
+	return platform_driver_probe(&shrm_driver, shrm_probe);
+}
+
+static void __exit shrm_driver_exit(void)
+{
+	platform_driver_unregister(&shrm_driver);
+}
+
+module_init(shrm_driver_init);
+module_exit(shrm_driver_exit);
+
+MODULE_AUTHOR("Biju Das, Kumar Sanghvi, Arun Murthy");
+MODULE_DESCRIPTION("Shared Memory Modem Driver Interface");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/misc/shrm/shrm_driver.c b/drivers/misc/shrm/shrm_driver.c
new file mode 100644
index 00000000000..6277794608a
--- /dev/null
+++ b/drivers/misc/shrm/shrm_driver.c
@@ -0,0 +1,1439 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define DEBUG
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/smp_lock.h>
+#include <linux/poll.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <asm/atomic.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include <mach/isa_ioctl.h>
+#include <mach/shrm_driver.h>
+#include <mach/shrm_private.h>
+#include <mach/shrm_config.h>
+#include <mach/shrm.h>
+
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+#include <linux/hrtimer.h>
+static struct hrtimer timer;
+#endif
+
+
+#define NAME "IPC_ISA"
+#define ISA_DEVICES 4
+/**debug functionality*/
+#define ISA_DEBUG 0
+
+#define ISI_MESSAGING (0)
+#define RPC_MESSAGING (1)
+#define AUDIO_MESSAGING (2)
+#define SECURITY_MESSAGING (3)
+
+#define SIZE_OF_FIFO (512*1024)
+
+static u8 message_fifo[4][SIZE_OF_FIFO];
+
+static u8 wr_isi_msg[10*1024];
+static u8 wr_rpc_msg[10*1024];
+static u8 wr_sec_msg[10*1024];
+static u8 wr_audio_msg[10*1024];
+
+/* global data */
+/*
+ * int major:This variable is exported to user as module_param to specify
+ * major number at load time
+ */
+static int major;
+module_param(major, int, 0);
+MODULE_PARM_DESC(major, "Major device number");
+/* global fops mutex */
+static DEFINE_MUTEX(isa_lock);
+rx_cb common_rx;
+rx_cb audio_rx;
+
+
+static int isi_receive(struct shrm_dev *shrm, void *data, u32 n_bytes);
+static int rpc_receive(struct shrm_dev *shrm, void *data, u32 n_bytes);
+static int audio_receive(struct shrm_dev *shrm, void *data, u32 n_bytes);
+static int security_receive(struct shrm_dev *shrm,
+						void *data, u32 n_bytes);
+
+static void rx_common_l2msg_handler(u8 l2_header,
+				 void *msg, u32 length,
+				 struct shrm_dev *shrm)
+{
+	int ret = 0;
+#ifdef CONFIG_U8500_SHRM_LOOP_BACK
+	u8 *pdata;
+#endif
+     dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	switch (l2_header) {
+	case ISI_MESSAGING:
+		ret = isi_receive(shrm, msg, length);
+		if (ret < 0)
+			dev_err(shrm->dev, "isi receive failed\n");
+		break;
+	case RPC_MESSAGING:
+		ret  = rpc_receive(shrm, msg, length);
+		if (ret < 0)
+			dev_err(shrm->dev, "rpc receive failed\n");
+		break;
+	case SECURITY_MESSAGING:
+		ret = security_receive(shrm, msg, length);
+		if (ret < 0)
+			dev_err(shrm->dev,
+					"security receive failed\n");
+		break;
+#ifdef CONFIG_U8500_SHRM_LOOP_BACK
+	case COMMMON_LOOPBACK_MESSAGING:
+		pdata = (u8 *)msg;
+		if ((*pdata == 0x50) || (*pdata == 0xAF)) {
+			ret = isi_receive(shrm, msg, length);
+			if (ret < 0)
+				dev_err(shrm->dev, "isi receive failed\n");
+		} else if ((*pdata == 0x0A) || (*pdata == 0xF5)) {
+			ret = rpc_receive(shrm, msg, length);
+			if (ret < 0)
+				dev_err(shrm->dev, "rpc receive failed\n");
+		} else if ((*pdata == 0xFF) || (*pdata == 0x00)) {
+			ret = security_receive(shrm, msg, length);
+			if (ret < 0)
+				dev_err(shrm->dev,
+						"security receive failed\n");
+		}
+		break;
+#endif
+	default:
+		break;
+	}
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+static void rx_audio_l2msg_handler(u8 l2_header,
+				void *msg, u32 length,
+				struct shrm_dev *shrm)
+{
+	int ret = 0;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	audio_receive(shrm, msg, length);
+	if (ret < 0)
+		dev_err(shrm->dev, "audio receive failed\n");
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+static int __init shm_initialise_irq(struct shrm_dev *shrm)
+{
+	int err = 0;
+
+	shrm_protocol_init(shrm,
+			rx_common_l2msg_handler, rx_audio_l2msg_handler);
+
+	err = request_irq(shrm->ca_wake_irq,
+			ca_wake_irq_handler, IRQF_TRIGGER_RISING,
+				 "ca_wake-up", shrm);
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"Unable to allocate shm tx interrupt line\n");
+		return err;
+	}
+
+	err = request_irq(shrm->ac_read_notif_0_irq,
+			ac_read_notif_0_irq_handler, 0,
+			"ac_read_notif_0", shrm);
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"error ac_read_notif_0_irq interrupt line\n");
+		goto irq_err1;
+	}
+
+	err = request_irq(shrm->ac_read_notif_1_irq,
+			ac_read_notif_1_irq_handler, 0,
+			"ac_read_notif_1", shrm);
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"error ac_read_notif_1_irq interrupt line\n");
+		goto irq_err2;
+	}
+
+	err = request_irq(shrm->ca_msg_pending_notif_0_irq,
+			 ca_msg_pending_notif_0_irq_handler, 0,
+			"ca_msg_pending_notif_0", shrm);
+	if (err < 0) {
+		dev_err(shrm->dev,
+				"error  ca_msg_pending_notif_0_irq line\n");
+		goto irq_err3;
+	}
+
+	err = request_irq(shrm->ca_msg_pending_notif_1_irq,
+			 ca_msg_pending_notif_1_irq_handler, 0,
+			"ca_msg_pending_notif_1", shrm);
+	if (err < 0) {
+		dev_err(shrm->dev,
+			"error ca_msg_pending_notif_1_irq interrupt line\n");
+		goto irq_err4;
+	}
+
+	return err;
+
+irq_err4:
+	free_irq(shrm->ca_msg_pending_notif_0_irq, shrm);
+irq_err3:
+	free_irq(shrm->ac_read_notif_1_irq, shrm);
+irq_err2:
+	free_irq(shrm->ac_read_notif_0_irq, shrm);
+irq_err1:
+	free_irq(shrm->ca_wake_irq, shrm);
+	return err;
+}
+
+static void free_shm_irq(struct shrm_dev *shrm)
+{
+	free_irq(shrm->ca_wake_irq, shrm);
+	free_irq(shrm->ac_read_notif_0_irq, shrm);
+	free_irq(shrm->ac_read_notif_1_irq, shrm);
+	free_irq(shrm->ca_msg_pending_notif_0_irq, shrm);
+	free_irq(shrm->ca_msg_pending_notif_1_irq, shrm);
+}
+
+/**
+ * create_queue() - To create FIFO for Tx and Rx message buffering.
+ * @q: message queue.
+ * @devicetype: device type 0-isi,1-rpc,2-audio,3-security.
+ *
+ * This function creates a FIFO buffer of n_bytes size using
+ * dma_alloc_coherent(). It also initializes all queue handling
+ * locks, queue management pointers. It also initializes message list
+ * which occupies this queue.
+ *
+ * It return -ENOMEM in case of no memory.
+ */
+static int create_queue(struct message_queue *q, u32 devicetype,
+					struct shrm_dev *shrm)
+{
+	q->fifo_base = (u8 *)&message_fifo[devicetype];
+	q->size = SIZE_OF_FIFO;
+	q->readptr = 0;
+	q->writeptr = 0;
+	q->no = 0;
+	q->shrm = shrm;
+	spin_lock_init(&q->update_lock);
+	INIT_LIST_HEAD(&q->msg_list);
+	init_waitqueue_head(&q->wq_readable);
+	atomic_set(&q->q_rp, 0);
+
+	return 0;
+}
+/**
+ * delete_queue() - To delete FIFO and assiciated memory.
+ * @q: message queue
+ *
+ * This function deletes FIFO created using create_queue() function.
+ * It resets queue management pointers.
+ */
+static void delete_queue(struct message_queue *q)
+{
+	q->size = 0;
+	q->readptr = 0;
+	q->writeptr = 0;
+}
+
+/**
+ * add_msg_to_queue() - Add a message inside inside queue
+ *
+ * @q: message queue
+ * @size: size in bytes
+ *
+ * This function tries to allocate n_bytes of size in FIFO q.
+ * It returns negative number when no memory can be allocated
+ * currently.
+ */
+int add_msg_to_queue(struct message_queue *q, u32 size)
+{
+	struct queue_element *new_msg = NULL;
+	struct shrm_dev *shrm = q->shrm;
+
+	dev_dbg(shrm->dev, "%s IN q->writeptr=%d\n",
+						__func__, q->writeptr);
+	new_msg = kmalloc(sizeof(struct queue_element),
+						 GFP_KERNEL|GFP_ATOMIC);
+
+	if (new_msg == NULL) {
+		dev_err(shrm->dev, "memory overflow inside while(1)\n");
+		return -ENOMEM;
+	}
+	new_msg->offset = q->writeptr;
+	new_msg->size = size;
+	new_msg->no = q->no++;
+
+	/* check for overflow condition */
+	if (q->readptr <= q->writeptr) {
+		if (((q->writeptr-q->readptr) + size) >= q->size) {
+			dev_err(shrm->dev, "Buffer overflow !!\n");
+			BUG_ON(((q->writeptr-q->readptr) + size) >= q->size);
+		}
+	} else {
+		if ((q->writeptr + size) >= q->readptr) {
+			dev_err(shrm->dev, "Buffer overflow !!\n");
+			BUG_ON((q->writeptr + size) >= q->readptr);
+		}
+	}
+	q->writeptr = (q->writeptr + size) % q->size;
+	if (list_empty(&q->msg_list)) {
+		list_add_tail(&new_msg->entry, &q->msg_list);
+		/* There can be 2 blocking calls read  and another select */
+
+		atomic_set(&q->q_rp, 1);
+		wake_up_interruptible(&q->wq_readable);
+	} else
+		list_add_tail(&new_msg->entry, &q->msg_list);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return 0;
+}
+
+/**
+ * remove_msg_from_queue() - To remove a message from the msg queue.
+ *
+ * @q: message queue
+ *
+ * This function delets a message from the message list associated with message
+ * queue q and also updates read ptr.
+ * If the message list is empty, then, event is set to block the select and
+ * read calls of the paricular queue.
+ *
+ * The message list is FIFO style and message is always added to tail and
+ * removed from head.
+ */
+
+int remove_msg_from_queue(struct message_queue *q)
+{
+	struct queue_element *old_msg = NULL;
+	struct shrm_dev *shrm = q->shrm;
+	struct list_head *msg;
+
+	dev_dbg(shrm->dev, "%s IN q->readptr %d\n",
+					__func__, q->readptr);
+
+	list_for_each(msg, &q->msg_list) {
+		old_msg = list_entry(msg, struct queue_element, entry);
+		if (old_msg == NULL) {
+			dev_err(shrm->dev, ":no message found\n");
+			return -EFAULT;
+		}
+		break;
+	}
+	list_del(msg);
+	q->readptr = (q->readptr + old_msg->size) % q->size;
+	if (list_empty(&q->msg_list)) {
+		dev_dbg(shrm->dev, "List is empty setting RP= 0\n");
+		atomic_set(&q->q_rp, 0);
+	}
+	kfree(old_msg);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return 0;
+}
+
+/**
+ * get_size_of_new_msg() - retrieve new message from message list
+ *
+ * @q: message queue
+ *
+ * This function will retrieve most recent message from the corresponding
+ * queue list. New message is always retrieved from head side.
+ * It returns new message no, offset if FIFO and size.
+ */
+int get_size_of_new_msg(struct message_queue *q)
+{
+	struct queue_element *new_msg = NULL;
+	struct list_head *msg_list;
+	struct shrm_dev *shrm = q->shrm;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	spin_lock_bh(&q->update_lock);
+	list_for_each(msg_list, &q->msg_list) {
+		new_msg = list_entry(msg_list, struct queue_element, entry);
+		if (new_msg == NULL) {
+			spin_unlock_bh(&q->update_lock);
+			dev_err(shrm->dev, "no message found\n");
+			return -1;
+		}
+		break;
+	}
+	spin_unlock_bh(&q->update_lock);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return new_msg->size;
+}
+
+/**
+ * isi_receive() - Rx Completion callback
+ *
+ * @data:message pointer
+ * @n_bytes:message size
+ *
+ * This function is a callback to indicate ISI message reception is complete.
+ * It updates Writeptr of the Fifo
+ */
+static int isi_receive(struct shrm_dev *shrm,
+					void *data, u32 n_bytes)
+{
+	u32 size = 0;
+	int ret = 0;
+	u8 *psrc;
+	struct message_queue *q;
+	struct isadev_context *isidev = &shrm->isa_context->isadev[0];
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	q = &isidev->dl_queue;
+	spin_lock(&q->update_lock);
+	/* Memcopy RX data first */
+	if ((q->writeptr+n_bytes) >= q->size) {
+		dev_dbg(shrm->dev, "Inside Loop Back\n");
+		psrc = (u8 *)data;
+		size = (q->size-q->writeptr);
+		/* Copy First Part of msg */
+		memcpy((q->fifo_base+q->writeptr), psrc, size);
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		memcpy(q->fifo_base, psrc, (n_bytes-size));
+	} else {
+		memcpy((q->fifo_base+q->writeptr), data, n_bytes);
+	}
+	ret = add_msg_to_queue(q, n_bytes);
+	if (ret < 0)
+		dev_err(shrm->dev, "Adding msg to message queue failed\n");
+	spin_unlock(&q->update_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * rpc_receive() - Rx Completion callback
+ *
+ * @data:message pointer
+ * @n_bytes:message size
+ *
+ * This function is a callback to indicate RPC message reception is complete.
+ * It updates Writeptr of the Fifo
+ */
+static int rpc_receive(struct shrm_dev *shrm,
+					void *data, u32 n_bytes)
+{
+	u32 size = 0;
+	int ret = 0;
+	u8 *psrc;
+	struct message_queue *q;
+	struct isadev_context *rpcdev = &shrm->isa_context->isadev[1];
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	q = &rpcdev->dl_queue;
+	spin_lock(&q->update_lock);
+	/* Memcopy RX data first */
+	if ((q->writeptr+n_bytes) >= q->size) {
+		psrc = (u8 *)data;
+		size = (q->size-q->writeptr);
+		/* Copy First Part of msg */
+		memcpy((q->fifo_base+q->writeptr), psrc, size);
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		memcpy(q->fifo_base, psrc, (n_bytes-size));
+	} else {
+		memcpy((q->fifo_base+q->writeptr), data, n_bytes);
+	}
+
+	ret = add_msg_to_queue(q, n_bytes);
+	if (ret < 0)
+		dev_err(shrm->dev, "Adding msg to message queue failed\n");
+	spin_unlock(&q->update_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * audio_receive() - Rx Completion callback
+ *
+ * @data:message pointer
+ * @n_bytes:message size
+ *
+ * This function is a callback to indicate audio message reception is complete.
+ * It updates Writeptr of the Fifo
+ */
+static int audio_receive(struct shrm_dev *shrm,
+					void *data, u32 n_bytes)
+{
+	u32 size = 0;
+	int ret = 0;
+	u8 *psrc;
+	struct message_queue *q;
+	struct isadev_context *audiodev = &shrm->isa_context->isadev[2];
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	q = &audiodev->dl_queue;
+	spin_lock(&q->update_lock);
+	/* Memcopy RX data first */
+	if ((q->writeptr+n_bytes) >= q->size) {
+		psrc = (u8 *)data;
+		size = (q->size-q->writeptr);
+		/* Copy First Part of msg */
+		memcpy((q->fifo_base+q->writeptr), psrc, size);
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		memcpy(q->fifo_base, psrc, (n_bytes-size));
+	} else {
+		memcpy((q->fifo_base+q->writeptr), data, n_bytes);
+	}
+	ret = add_msg_to_queue(q, n_bytes);
+	if (ret < 0)
+		dev_err(shrm->dev, "Adding msg to message queue failed\n");
+	spin_unlock(&q->update_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * security_receive() - Rx Completion callback
+ *
+ * @data:message pointer
+ * @n_bytes: message size
+ *
+ * This function is a callback to indicate security message reception
+ * is complete.It updates Writeptr of the Fifo
+ */
+static int security_receive(struct shrm_dev *shrm,
+					void *data, u32 n_bytes)
+{
+	u32 size = 0;
+	int ret = 0;
+	u8 *psrc;
+	struct message_queue *q;
+	struct isadev_context *secdev = &shrm->isa_context->isadev[3];
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	q = &secdev->dl_queue;
+	spin_lock(&q->update_lock);
+	/* Memcopy RX data first */
+	if ((q->writeptr+n_bytes) >= q->size) {
+		psrc = (u8 *)data;
+		size = (q->size-q->writeptr);
+		/* Copy First Part of msg */
+		memcpy((q->fifo_base+q->writeptr), psrc, size);
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		memcpy(q->fifo_base, psrc, (n_bytes-size));
+	} else {
+		memcpy((q->fifo_base+q->writeptr), data, n_bytes);
+	}
+	ret = add_msg_to_queue(q, n_bytes);
+	if (ret < 0)
+		dev_err(shrm->dev, "Adding msg to message queue failed\n");
+	spin_unlock(&q->update_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+
+/**
+ * isa_select() - Select Interface
+ *
+ * @filp:file descriptor pointer
+ * @wait:poll_table_struct pointer
+ *
+ * This function is used to perform non-blocking read operations. It allows
+ * a process to determine whether it can read from one or more open files
+ * without blocking. These calls can also block a process until any of a
+ * given set of file descriptors becomes available for reading.
+ * If a file is ready to read, POLLIN | POLLRDNORM bitmask is returned.
+ * The driver method is called whenever the user-space program performs a select
+ * system call involving a file descriptor associated with the driver.
+ */
+static u32 isa_select(struct file *filp,
+				struct poll_table_struct *wait)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct message_queue *q;
+	u32 mask = 0;
+	u32 m = iminor(filp->f_path.dentry->d_inode);
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (isadev->device_id != m)
+			return -1;
+	q = &isadev->dl_queue;
+	poll_wait(filp, &q->wq_readable, wait);
+	if (atomic_read(&q->q_rp) == 1)
+		mask = POLLIN | POLLRDNORM;
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return mask;
+}
+
+/**
+ * isa_read() - Read from device
+ *
+ * @filp:file descriptor
+ * @buf:user buffer pointer
+ * @len:size of requested data transfer
+ * @ppos:not used
+ *
+ * This function is called whenever user calls read() system call.
+ * It reads a oldest message from queue and copies it into user buffer and
+ * returns its size.
+ * If there is no message present in queue, then it blocks until new data is
+ * available.
+ */
+ssize_t isa_read(struct file *filp, char __user *buf,
+				size_t len, loff_t *ppos)
+{
+	struct isadev_context *isadev = (struct isadev_context *)
+							filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct message_queue *q;
+	char *psrc;
+	u32 msgsize;
+	u32 size = 0;
+	int ret = 0;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (len <= 0)
+		return -EFAULT;
+	q = &isadev->dl_queue;
+
+	spin_lock_bh(&q->update_lock);
+	if (list_empty(&q->msg_list)) {
+		spin_unlock_bh(&q->update_lock);
+		if (wait_event_interruptible(q->wq_readable,
+				atomic_read(&q->q_rp) == 1)) {
+			return -ERESTARTSYS;
+		}
+	} else
+		spin_unlock_bh(&q->update_lock);
+
+	msgsize = get_size_of_new_msg(q);
+	if ((q->readptr+msgsize) >= q->size) {
+		dev_dbg(shrm->dev, "Inside Loop Back\n");
+		psrc = (char *)buf;
+		size = (q->size-q->readptr);
+		/* Copy First Part of msg */
+		if (copy_to_user(psrc,
+				(u8 *)(q->fifo_base+q->readptr),
+				size)) {
+			dev_err(shrm->dev, "copy_to_user failed\n");
+			return -EFAULT;
+		}
+		psrc += size;
+		/* Copy Second Part of msg at the top of fifo */
+		if (copy_to_user(psrc,
+				(u8 *)(q->fifo_base),
+				(msgsize-size))) {
+			dev_err(shrm->dev, "copy_to_user failed\n");
+			return -EFAULT;
+		}
+	} else {
+		if (copy_to_user(buf,
+				(u8 *)(q->fifo_base+q->readptr),
+				msgsize)) {
+			dev_err(shrm->dev, "copy_to_user failed\n");
+			return -EFAULT;
+		}
+	}
+
+	spin_lock_bh(&q->update_lock);
+	ret = remove_msg_from_queue(q);
+	if (ret < 0) {
+		dev_err(shrm->dev,
+				"Removing msg from message queue failed\n");
+		msgsize = ret;
+	}
+	spin_unlock_bh(&q->update_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return msgsize;
+}
+/**
+ * isa_write() - Write to device
+ *
+ * @filp:file descriptor
+ * @buf:user buffer pointer
+ * @len:size of requested data transfer
+ * @ppos:not used
+ *
+ * This function is called whenever user calls write() system call.
+ * It checks if there is space available in queue, and copies the message
+ * inside queue. If there is no space, it blocks until space becomes available.
+ * It also schedules transfer thread to transmit the newly added message.
+ */
+static ssize_t isa_write(struct file *filp, const char __user *buf,
+				 size_t len, loff_t *ppos)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct message_queue *q;
+	int err, ret;
+	void *addr = 0;
+	u8 l2_header = 0;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	if (len <= 0)
+		return -EFAULT;
+	q = &isadev->dl_queue;
+
+	switch (isadev->device_id) {
+	case ISI_MESSAGING:
+		dev_dbg(shrm->dev, "ISI\n");
+		addr = (void *)wr_isi_msg;
+#ifdef CONFIG_U8500_SHRM_LOOP_BACK
+		dev_dbg(shrm->dev, "Loopback\n");
+		l2_header = COMMON_LOOPBACK_MESSAGING;
+#else
+		l2_header = isadev->device_id;
+#endif
+		break;
+	case RPC_MESSAGING:
+		dev_dbg(shrm->dev, "RPC\n");
+		addr = (void *)wr_rpc_msg;
+#ifdef CONFIG_U8500_SHRM_LOOP_BACK
+		l2_header = COMMON_LOOPBACK_MESSAGING;
+#else
+		l2_header = isadev->device_id;
+#endif
+		break;
+	case AUDIO_MESSAGING:
+		dev_dbg(shrm->dev, "Audio\n");
+		addr = (void *)wr_audio_msg;
+#ifdef CONFIG_U8500_SHRM_LOOP_BACK
+		l2_header = AUDIO_LOOPBACK_MESSAGING;
+#else
+		l2_header = isadev->device_id;
+#endif
+
+		break;
+	case SECURITY_MESSAGING:
+		dev_dbg(shrm->dev, "Security\n");
+		addr = (void *)wr_sec_msg;
+#ifdef CONFIG_U8500_SHRM_LOOP_BACK
+		l2_header = COMMON_LOOPBACK_MESSAGING;
+#else
+		l2_header = isadev->device_id;
+#endif
+		break;
+	default:
+		dev_dbg(shrm->dev, "Wrong device\n");
+		return -EFAULT;
+	}
+
+	if (copy_from_user(addr, buf, len)) {
+		dev_err(shrm->dev, "copy_from_user failed\n");
+		return -EFAULT;
+	}
+
+	/* Write msg to Fifo */
+	if (isadev->device_id == 2) {
+		mutex_lock(&shrm->isa_context->tx_audio_mutex);
+		err = shm_write_msg(shrm, l2_header, addr, len);
+		if (!err)
+			ret = len;
+		else
+			ret = err;
+		mutex_unlock(&shrm->isa_context->tx_audio_mutex);
+	} else {
+		spin_lock_bh(&shrm->isa_context->common_tx);
+		err = shm_write_msg(shrm, l2_header, addr, len);
+		if (!err)
+			ret = len;
+		else
+			ret = err;
+		spin_unlock_bh(&shrm->isa_context->common_tx);
+	}
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return ret;
+}
+
+/**
+ * isa_ioctl() - To handle different ioctl commands supported by driver.
+ *
+ * @inode: structure is used by the kernel internally to represent files
+ * @filp:file descriptor pointer
+ * @cmd:ioctl command
+ * @arg:input param
+ *
+ * Following ioctls are supported by this driver.
+ * DLP_IOCTL_ALLOCATE_BUFFER - To allocate buffer for new uplink message.
+ * This ioctl is called with required message size. It returns offset for
+ * the allocates space in the queue. DLP_IOCTL_PUT_MESSAGE -  To indicate
+ * new uplink message available in queuq for  transmission. Message is copied
+ * from offset location returned by previous ioctl before calling this ioctl.
+ * DLP_IOCTL_GET_MESSAGE - To check if any downlink message is available in
+ * queue. It returns  offset for new message inside queue.
+ * DLP_IOCTL_DEALLOCATE_BUFFER - To deallocate any buffer allocate for
+ * downlink message once the message is copied. Message is copied from offset
+ * location returned by previous ioctl before calling this ioctl.
+ */
+static int isa_ioctl(struct inode *inode, struct file *filp,
+				unsigned cmd, unsigned long arg)
+{
+	int err = 0;
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	u32 m = iminor(inode);
+
+	if (isadev->device_id != m)
+		return -1;
+
+	switch (cmd) {
+	case DLP_IOC_ALLOCATE_BUFFER:
+		dev_dbg(shrm->dev, "DLP_IOC_ALLOCATE_BUFFER\n");
+		break;
+	case DLP_IOC_PUT_MESSAGE:
+		dev_dbg(shrm->dev, "DLP_IOC_PUT_MESSAGE\n");
+		break;
+	case DLP_IOC_GET_MESSAGE:
+		dev_dbg(shrm->dev, "DLP_IOC_GET_MESSAGE\n");
+		break;
+	case DLP_IOC_DEALLOCATE_BUFFER:
+		dev_dbg(shrm->dev, "DLP_IOC_DEALLOCATE_BUFFER\n");
+		break;
+	default:
+		dev_dbg(shrm->dev, "Unknown IOCTL\n");
+		err = -1;
+		break;
+	}
+	return err;
+}
+/**
+ * isa_mmap() - Maps kernel queue memory to user space.
+ *
+ * @filp:file descriptor pointer
+ * @vma:virtual area memory structure.
+ *
+ * This function maps kernel FIFO into user space. This function
+ * shall be called twice to map both uplink and downlink buffers.
+ */
+static int isa_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+
+	u32	m = iminor(filp->f_path.dentry->d_inode);
+	dev_dbg(shrm->dev, "%s %dIN\n", __func__, m);
+
+	isadev = (struct isadev_context *)filp->private_data;
+	return 0;
+}
+
+/**
+ * isa_close() - Close device file
+ *
+ * @inode:structure is used by the kernel internally to represent files
+ * @filp:device file descriptor
+ *
+ * This function deletes structues associated with this file, deletes
+ * queues, flushes and destroys workqueus and closes this file.
+ * It also unregisters itself from l2mux driver.
+ */
+static int isa_close(struct inode *inode, struct file *filp)
+{
+	struct isadev_context *isadev = filp->private_data;
+	struct shrm_dev *shrm = isadev->dl_queue.shrm;
+	struct isa_driver_context *isa_context = shrm->isa_context;
+	u8 m;
+
+	mutex_lock(&isa_lock);
+	m = iminor(filp->f_path.dentry->d_inode);
+	dev_dbg(shrm->dev, "%s IN %d", __func__, m);
+
+	if (atomic_dec_and_test(&isa_context->is_open[m])) {
+		atomic_inc(&isa_context->is_open[m]);
+		dev_err(shrm->dev, "Device not opened yet\n");
+		mutex_unlock(&isa_lock);
+		return -ENODEV;
+	}
+	atomic_set(&isa_context->is_open[m], 1);
+
+	dev_dbg(shrm->dev, "isadev->device_id %d", isadev->device_id);
+	dev_dbg(shrm->dev, "Closed %d device\n", m);
+
+	if (m == ISI_MESSAGING)
+		dev_dbg(shrm->dev, "Closed ISI_MESSAGING Device\n");
+	else if (m == RPC_MESSAGING)
+		dev_dbg(shrm->dev, "Closed RPC_MESSAGING Device\n");
+	else if (m == AUDIO_MESSAGING)
+		dev_dbg(shrm->dev, "Closed AUDIO_MESSAGING Device\n");
+	else if (m == SECURITY_MESSAGING)
+		dev_dbg(shrm->dev, "Closed SECURITY_MESSAGING Device\n");
+	else
+		dev_dbg(shrm->dev, NAME ":No such device present\n");
+
+	mutex_unlock(&isa_lock);
+	return 0;
+}
+/**
+ * isa_open() -  Open device file
+ *
+ * @inode: structure is used by the kernel internally to represent files
+ * @filp: device file descriptor
+ *
+ * This function performs initialization tasks needed to open SHM channel.
+ * Following tasks are performed.
+ * -return if device is already opened
+ * -create uplink FIFO
+ * -create downlink FIFO
+ * -init delayed workqueue thread
+ * -register to l2mux driver
+ */
+static int isa_open(struct inode *inode, struct file *filp)
+{
+	int err = 0;
+	u8 m;
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context = container_of(
+			inode->i_cdev,
+			struct isa_driver_context,
+			cdev);
+	struct shrm_dev *shrm = isa_context->isadev->dl_queue.shrm;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (get_boot_state() != BOOT_DONE) {
+		dev_err(shrm->dev, "Boot is not done\n");
+		return -EBUSY;
+	}
+	mutex_lock(&isa_lock);
+	m = iminor(inode);
+
+	if ((m != ISI_MESSAGING) && (m != RPC_MESSAGING) &&
+		(m != AUDIO_MESSAGING) && (m != SECURITY_MESSAGING)) {
+		dev_err(shrm->dev, "No such device present\n");
+		mutex_unlock(&isa_lock);
+		return -ENODEV;
+	}
+	if (!atomic_dec_and_test(&isa_context->is_open[m])) {
+		atomic_inc(&isa_context->is_open[m]);
+		dev_err(shrm->dev, "Device already opened\n");
+		mutex_unlock(&isa_lock);
+		return -EBUSY;
+	}
+
+	if (m == ISI_MESSAGING)
+		dev_dbg(shrm->dev, "Open ISI_MESSAGING Device\n");
+	else if (m == RPC_MESSAGING)
+		dev_dbg(shrm->dev, "Open RPC_MESSAGING Device\n");
+	else if (m == AUDIO_MESSAGING)
+		dev_dbg(shrm->dev, "Open AUDIO_MESSAGING Device\n");
+	else if (m == SECURITY_MESSAGING)
+		dev_dbg(shrm->dev, "Open SECURITY_MESSAGING Device\n");
+	else
+		dev_dbg(shrm->dev, ":No such device present\n");
+
+	isadev = &isa_context->isadev[m];
+	if (filp != NULL)
+		filp->private_data = isadev;
+
+	mutex_unlock(&isa_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return err;
+}
+
+const struct file_operations isa_fops = {
+	.owner	= THIS_MODULE,
+	.open 	= isa_open,
+	.release = isa_close,
+	.ioctl 	= isa_ioctl,
+	.mmap 	= isa_mmap,
+	.read 	= isa_read,
+	.write 	= isa_write,
+	.poll	= isa_select,
+};
+
+/**
+ * isa_init() - module insertion function
+ *
+ * This function registers module as a character driver using
+ * register_chrdev_region() or alloc_chrdev_region. It adds this
+ * driver to system using cdev_add() call. Major number is dynamically
+ * allocated using alloc_chrdev_region() by default or left to user to specify
+ * it during load time. For this variable major is used as module_param
+ * Nodes to be created using
+ * mknod /dev/isi c $major 0
+ * mknod /dev/rpc c $major 1
+ * mknod /dev/audio c $major 2
+ * mknod /dev/sec c $major 3
+ */
+int isa_init(struct shrm_dev *shrm)
+{
+	dev_t	dev_id;
+	int	retval, no_dev;
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context;
+
+	isa_context = kzalloc(sizeof(struct isa_driver_context),
+							GFP_KERNEL);
+	shrm->isa_context = isa_context;
+	if (isa_context == NULL) {
+		dev_err(shrm->dev, "Failed to alloc memory\n");
+		return -ENOMEM;
+	}
+
+	if (major) {
+		dev_id = MKDEV(major, 0);
+		retval = register_chrdev_region(dev_id, ISA_DEVICES, NAME);
+	} else {
+		retval = alloc_chrdev_region(&dev_id, 0, ISA_DEVICES, NAME);
+		major = MAJOR(dev_id);
+	}
+
+	dev_dbg(shrm->dev, "major %d\n", major);
+
+	cdev_init(&isa_context->cdev, &isa_fops);
+	isa_context->cdev.owner = THIS_MODULE;
+	retval = cdev_add(&isa_context->cdev, dev_id, ISA_DEVICES);
+	if (retval) {
+		dev_err(shrm->dev, "Failed to add char device\n");
+		return retval;
+	}
+
+	for (no_dev = 0; no_dev < ISA_DEVICES; no_dev++)
+		atomic_set(&isa_context->is_open[no_dev], 1);
+
+	isa_context->isadev = kzalloc(sizeof
+					(struct isadev_context)*ISA_DEVICES,
+					GFP_KERNEL);
+	if (isa_context->isadev == NULL) {
+		dev_err(shrm->dev, "Failed to alloc memory\n");
+		return -ENOMEM;
+	}
+	for (no_dev = 0; no_dev < ISA_DEVICES; no_dev++) {
+		isadev = &isa_context->isadev[no_dev];
+		isadev->device_id = no_dev;
+		retval = create_queue(&isadev->dl_queue,
+					isadev->device_id, shrm);
+		if (retval < 0) {
+			dev_err(shrm->dev, "create dl_queue failed\n");
+			delete_queue(&isadev->dl_queue);
+			kfree(isadev);
+			return retval;
+		}
+	}
+	mutex_init(&isa_context->tx_audio_mutex);
+	spin_lock_init(&isa_context->common_tx);
+
+	dev_err(shrm->dev, "SHRM char driver added\n");
+
+	return retval;
+}
+
+void isa_exit(struct shrm_dev *shrm)
+{
+	int	no_dev;
+	struct isadev_context *isadev;
+	struct isa_driver_context *isa_context = shrm->isa_context;
+	dev_t dev_id = MKDEV(major, 0);
+
+	for (no_dev = 0; no_dev < ISA_DEVICES; no_dev++) {
+		isadev = &isa_context->isadev[no_dev];
+		delete_queue(&isadev->dl_queue);
+		kfree(isadev);
+	}
+
+	cdev_del(&isa_context->cdev);
+	unregister_chrdev_region(dev_id, ISA_DEVICES);
+	kfree(isa_context);
+
+	dev_err(shrm->dev, "SHRM char driver removed\n");
+}
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+static enum hrtimer_restart callback(struct hrtimer *timer)
+{
+	return HRTIMER_NORESTART;
+}
+#endif
+
+
+static int __init shrm_probe(struct platform_device *pdev)
+{
+	int err = 0;
+	struct resource *res;
+	struct shrm_dev *shrm = NULL;
+
+	if (pdev == NULL)  {
+		dev_err(shrm->dev,
+			"No device/platform_data found on shm device\n");
+		return -ENODEV;
+	}
+
+
+	shrm = kzalloc(sizeof(struct shrm_dev), GFP_KERNEL);
+	if (shrm == NULL) {
+		dev_err(shrm->dev,
+			"Could not allocate memory for struct shm_dev\n");
+		return -ENOMEM;
+	}
+	shrm->dev = &pdev->dev;
+
+	/* initialise the SHM */
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(shrm->dev, "Unable to map Ca Wake up interrupt\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ca_wake_irq = res->start;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map APE_Read_notif_common IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ac_read_notif_0_irq = res->start;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 2);
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map APE_Read_notif_audio IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ac_read_notif_1_irq = res->start;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 3);
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map Cmt_msg_pending_notif_common IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ca_msg_pending_notif_0_irq = res->start;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 4);
+	if (!res) {
+		dev_err(shrm->dev,
+			"Unable to map Cmt_msg_pending_notif_audio IRQ base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+	shrm->ca_msg_pending_notif_1_irq = res->start;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(shrm->dev,
+				"Could not get SHM IO memory information\n");
+		err = -ENODEV;
+		goto rollback_intr;
+	}
+
+	shrm->intr_base = (void __iomem *)ioremap_nocache(res->start,
+					res->end - res->start + 1);
+
+	if (!(shrm->intr_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_intr;
+	}
+
+	shrm->ape_common_fifo_base_phy =
+			(u32 *)U8500_SHM_FIFO_APE_COMMON_BASE;
+	shrm->ape_common_fifo_base =
+		(void __iomem *)ioremap_nocache(
+					U8500_SHM_FIFO_APE_COMMON_BASE,
+					SHM_FIFO_0_SIZE);
+	shrm->ape_common_fifo_size = (SHM_FIFO_0_SIZE)/4;
+
+	if (!(shrm->ape_common_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_ape_common_fifo_base;
+	}
+
+	shrm->cmt_common_fifo_base_phy =
+		(u32 *)U8500_SHM_FIFO_CMT_COMMON_BASE;
+
+	shrm->cmt_common_fifo_base =
+		(void __iomem *)ioremap_nocache(
+			U8500_SHM_FIFO_CMT_COMMON_BASE, SHM_FIFO_0_SIZE);
+	shrm->cmt_common_fifo_size = (SHM_FIFO_0_SIZE)/4;
+
+	if (!(shrm->cmt_common_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_cmt_common_fifo_base;
+	}
+
+	shrm->ape_audio_fifo_base_phy =
+			(u32 *)U8500_SHM_FIFO_APE_AUDIO_BASE;
+	shrm->ape_audio_fifo_base =
+		(void __iomem *)ioremap_nocache(U8500_SHM_FIFO_APE_AUDIO_BASE,
+							SHM_FIFO_1_SIZE);
+	shrm->ape_audio_fifo_size = (SHM_FIFO_1_SIZE)/4;
+
+	if (!(shrm->ape_audio_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_ape_audio_fifo_base;
+	}
+
+	shrm->cmt_audio_fifo_base_phy =
+			(u32 *)U8500_SHM_FIFO_CMT_AUDIO_BASE;
+	shrm->cmt_audio_fifo_base =
+		(void __iomem *)ioremap_nocache(U8500_SHM_FIFO_CMT_AUDIO_BASE,
+							SHM_FIFO_1_SIZE);
+	shrm->cmt_audio_fifo_size = (SHM_FIFO_1_SIZE)/4;
+
+	if (!(shrm->cmt_audio_fifo_base)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_cmt_audio_fifo_base;
+	}
+
+	shrm->ac_common_shared_wptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_0_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_common_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_ac_common_shared_wptr;
+	}
+
+	shrm->ac_common_shared_rptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_0_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_common_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+
+	shrm->ca_common_shared_wptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_0_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_common_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+	shrm->ca_common_shared_rptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_0_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_common_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+
+	shrm->ac_audio_shared_wptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_1_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_audio_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+
+	shrm->ac_audio_shared_rptr =
+		(void __iomem *)ioremap(SHM_ACFIFO_1_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ac_audio_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+
+	shrm->ca_audio_shared_wptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_1_WRITE_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_audio_shared_wptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+
+	shrm->ca_audio_shared_rptr =
+		(void __iomem *)ioremap(SHM_CAFIFO_1_READ_AMCU, SHM_PTR_SIZE);
+
+	if (!(shrm->ca_audio_shared_rptr)) {
+		dev_err(shrm->dev, "Unable to map register base\n");
+		err = -EBUSY;
+		goto rollback_map;
+	}
+
+
+	if (isa_init(shrm) != 0) {
+		dev_err(shrm->dev, "Driver Initialization Error\n");
+		err = -EBUSY;
+	}
+	/* install handlers and tasklets */
+	if (shm_initialise_irq(shrm)) {
+		dev_err(shrm->dev, "shm error in interrupt registration\n");
+		goto rollback_irq;
+	}
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+	hrtimer_init(&timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	timer.function = callback;
+
+	hrtimer_start(&timer, ktime_set(0, 2*NSEC_PER_MSEC), HRTIMER_MODE_REL);
+#endif
+
+	return err;
+
+rollback_irq:
+	free_shm_irq(shrm);
+rollback_map:
+	iounmap(shrm->ac_common_shared_wptr);
+	iounmap(shrm->ac_common_shared_rptr);
+	iounmap(shrm->ca_common_shared_wptr);
+	iounmap(shrm->ca_common_shared_rptr);
+	iounmap(shrm->ac_audio_shared_wptr);
+	iounmap(shrm->ac_audio_shared_rptr);
+	iounmap(shrm->ca_audio_shared_wptr);
+	iounmap(shrm->ca_audio_shared_rptr);
+rollback_ac_common_shared_wptr:
+	iounmap(shrm->cmt_audio_fifo_base);
+rollback_cmt_audio_fifo_base:
+	iounmap(shrm->ape_audio_fifo_base);
+rollback_ape_audio_fifo_base:
+	iounmap(shrm->cmt_common_fifo_base);
+rollback_cmt_common_fifo_base:
+	iounmap(shrm->ape_common_fifo_base);
+rollback_ape_common_fifo_base:
+	iounmap(shrm->intr_base);
+rollback_intr:
+	kfree(shrm);
+	return err;
+}
+
+static int __exit shrm_remove(struct platform_device *pdev)
+{
+	struct shrm_dev *shrm = platform_get_drvdata(pdev);
+
+	free_shm_irq(shrm);
+	iounmap(shrm->intr_base);
+	iounmap(shrm->ape_common_fifo_base);
+	iounmap(shrm->cmt_common_fifo_base);
+	iounmap(shrm->ape_audio_fifo_base);
+	iounmap(shrm->cmt_audio_fifo_base);
+	iounmap(shrm->ac_common_shared_wptr);
+	iounmap(shrm->ac_common_shared_rptr);
+	iounmap(shrm->ca_common_shared_wptr);
+	iounmap(shrm->ca_common_shared_rptr);
+	iounmap(shrm->ac_audio_shared_wptr);
+	iounmap(shrm->ac_audio_shared_rptr);
+	iounmap(shrm->ca_audio_shared_wptr);
+	iounmap(shrm->ca_audio_shared_rptr);
+	kfree(shrm);
+	isa_exit(shrm);
+
+	return 0;
+}
+#ifdef CONFIG_PM
+
+/**
+ * u8500_shrm_suspend() - This routine puts the SHRM in to sustend state.
+ * @pdev: platform device.
+ *
+ * This routine checks the current ongoing communication with Modem by
+ * examining the ca_wake state and prevents suspend if modem communication
+ * is on-going.
+ * If ca_wake = 1 (high), modem comm. is on-going; don't suspend
+ * If ca_wake = 0 (low), no comm. with modem on-going.Allow suspend
+ */
+int u8500_shrm_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct shrm_dev *shrm = platform_get_drvdata(pdev);
+
+	dev_dbg(shrm->dev, "%s called...\n", __func__);
+	dev_dbg(shrm->dev, "\n ca_wake_req_state = %x\n",
+					get_ca_wake_req_state());
+	/* if ca_wake_req is high, prevent system suspend */
+	if (get_ca_wake_req_state())
+		return -EBUSY;
+	else
+		return 0;
+}
+
+/**
+ * u8500_shrm_resume() - This routine resumes the SHRM from sustend state.
+ * @pdev: platform device.
+ *
+ * This routine restore back the current state of the SHRM
+ */
+int u8500_shrm_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct shrm_dev *shrm = platform_get_drvdata(pdev);
+
+	dev_dbg(shrm->dev, "%s called...\n", __func__);
+	/* TODO:
+	 * As of now, no state save takes place in suspend.
+	 * So, nothing to restore in resume.
+	 * Simply return as of now.
+	 * State saved in suspend should be restored here.
+	 */
+
+	return 0;
+}
+
+static const struct dev_pm_ops shrm_dev_pm_ops = {
+	.suspend = u8500_shrm_suspend,
+	.resume = u8500_shrm_resume,
+};
+#endif
+
+static struct platform_driver shrm_driver = {
+	.remove = __exit_p(shrm_remove),
+	.driver = {
+		.name = "u8500_shrm",
+		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm = &shrm_dev_pm_ops,
+#endif
+	},
+};
+
+static int __init shrm_driver_init(void)
+{
+	return platform_driver_probe(&shrm_driver, shrm_probe);
+}
+
+static void __exit shrm_driver_exit(void)
+{
+	platform_driver_unregister(&shrm_driver);
+}
+
+module_init(shrm_driver_init);
+module_exit(shrm_driver_exit);
+
+MODULE_AUTHOR("Biju Das");
+MODULE_DESCRIPTION("Shared Memory Modem Driver Interface");
+MODULE_LICENSE("GPL");
diff --git a/drivers/misc/shrm/shrm_fifo.c b/drivers/misc/shrm/shrm_fifo.c
new file mode 100644
index 00000000000..ecf4b7e4466
--- /dev/null
+++ b/drivers/misc/shrm/shrm_fifo.c
@@ -0,0 +1,829 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghavi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <mach/shrm.h>
+#include <mach/shrm_driver.h>
+#include <mach/shrm_private.h>
+#include <mach/shrm_net.h>
+
+#define L1_BOOT_INFO_REQ	1
+#define L1_BOOT_INFO_RESP	2
+#define L1_NORMAL_MSG		3
+#define L1_HEADER_MASK		28
+#define L1_MAPID_MASK		0xF0000000
+#define CONFIG_OFFSET		8
+#define COUNTER_OFFSET		20
+#define L2_HEADER_SIZE		4
+#define L2_HEADER_OFFSET	24
+#define MASK_0_15_BIT		0xFF
+#define MASK_16_31_BIT		0xFF00
+#define MASK_16_27_BIT		0xFFF0000
+#define MASK_0_39_BIT		0xFFFFF
+#define MASK_40_55_BIT		0xFF00000
+#define MASK_8_16_BIT           0x0000FF00
+#define MSG_LEN_OFFSET          16
+#define SHRM_VER                2
+#define ca_ist_inactivity_timer 100 /*100ms */
+#define ca_csc_inactivity_timer 100 /*100ms */
+
+static u8 msg_audio_counter;
+static u8 msg_common_counter;
+
+struct fifo_write_params ape_shm_fifo_0;
+struct fifo_write_params ape_shm_fifo_1;
+struct fifo_read_params cmt_shm_fifo_0;
+struct fifo_read_params cmt_shm_fifo_1;
+
+
+static u8 cmt_read_notif_0_send;
+static u8 cmt_read_notif_1_send;
+
+void shm_fifo_init(struct shrm_dev *shrm)
+{
+	ape_shm_fifo_0.writer_local_wptr	= 0;
+	ape_shm_fifo_0.writer_local_rptr	= 0;
+	*((u32 *)shrm->ac_common_shared_wptr) = 0;
+	*((u32 *)shrm->ac_common_shared_rptr) = 0;
+	ape_shm_fifo_0.shared_wptr		= 0;
+	ape_shm_fifo_0.shared_rptr		= 0;
+	ape_shm_fifo_0.availablesize = shrm->ape_common_fifo_size;
+	ape_shm_fifo_0.end_addr_fifo    = shrm->ape_common_fifo_size;
+	ape_shm_fifo_0.fifo_virtual_addr = shrm->ape_common_fifo_base;
+	spin_lock_init(&ape_shm_fifo_0.fifo_update_lock);
+
+
+	cmt_shm_fifo_0.reader_local_rptr	= 0;
+	cmt_shm_fifo_0.reader_local_wptr	= 0;
+	cmt_shm_fifo_0.shared_wptr	=
+			*((u32 *)shrm->ca_common_shared_wptr);
+	cmt_shm_fifo_0.shared_rptr	=
+			*((u32 *)shrm->ca_common_shared_rptr);
+	cmt_shm_fifo_0.availablesize	= shrm->cmt_common_fifo_size;
+	cmt_shm_fifo_0.end_addr_fifo	= shrm->cmt_common_fifo_size;
+	cmt_shm_fifo_0.fifo_virtual_addr = shrm->cmt_common_fifo_base;
+
+	ape_shm_fifo_1.writer_local_wptr	= 0;
+	ape_shm_fifo_1.writer_local_rptr	= 0;
+	ape_shm_fifo_1.shared_wptr		= 0;
+	ape_shm_fifo_1.shared_rptr		= 0;
+	*((u32 *)shrm->ac_audio_shared_wptr) = 0;
+	*((u32 *)shrm->ac_audio_shared_rptr) = 0;
+	ape_shm_fifo_1.availablesize = shrm->ape_audio_fifo_size;
+	ape_shm_fifo_1.end_addr_fifo    = shrm->ape_audio_fifo_size;
+	ape_shm_fifo_1.fifo_virtual_addr = shrm->ape_audio_fifo_base;
+	spin_lock_init(&ape_shm_fifo_1.fifo_update_lock);
+
+	cmt_shm_fifo_1.reader_local_rptr	= 0;
+	cmt_shm_fifo_1.reader_local_wptr	= 0;
+	cmt_shm_fifo_1.shared_wptr		=
+			*((u32 *)shrm->ca_audio_shared_wptr);
+	cmt_shm_fifo_1.shared_rptr		=
+			*((u32 *)shrm->ca_audio_shared_rptr);
+	cmt_shm_fifo_1.availablesize	= shrm->cmt_audio_fifo_size;
+	cmt_shm_fifo_1.end_addr_fifo	= shrm->cmt_audio_fifo_size;
+	cmt_shm_fifo_1.fifo_virtual_addr = shrm->cmt_audio_fifo_base;
+	msg_audio_counter = 0;
+	msg_common_counter = 0;
+}
+
+u8 read_boot_info_req(struct shrm_dev *shrm,
+				u32 *config,
+				u32 *version)
+{
+	struct fifo_read_params *fifo = &cmt_shm_fifo_0;
+	u32 *msg;
+	u32 header = 0;
+	u8 msgtype;
+
+	/* Read L1 header read content of reader_local_rptr */
+	msg = (u32 *)
+		(fifo->reader_local_rptr + fifo->fifo_virtual_addr);
+	header = *msg;
+	msgtype = (header & L1_MAPID_MASK) >> L1_MSG_MAPID_OFFSET;
+	if (msgtype != L1_BOOT_INFO_REQ) {
+		dev_err(shrm->dev, "Read_Boot_Info_Req Fatal ERROR\n");
+		BUG();
+	}
+	*config = (header >> CONFIG_OFFSET) & MASK_0_15_BIT;
+	*version = header & MASK_0_15_BIT;
+	fifo->reader_local_rptr += 1;
+
+	return 1;
+}
+
+void write_boot_info_resp(struct shrm_dev *shrm, u32 config,
+							u32 version)
+{
+	struct fifo_write_params *fifo = &ape_shm_fifo_0;
+	u32 *msg;
+	u8 msg_length;
+	version = SHRM_VER;
+
+	/* Read L1 header read content of reader_local_rptr */
+	msg = (u32 *)
+		(fifo->writer_local_wptr+fifo->fifo_virtual_addr);
+	if (version < 1)	{
+		*msg = ((L1_BOOT_INFO_RESP << L1_MSG_MAPID_OFFSET) |
+				((config << CONFIG_OFFSET) & MASK_16_31_BIT)
+				| (version & MASK_0_15_BIT));
+		msg_length = 1;
+	} else {
+		*msg = ((L1_BOOT_INFO_RESP << L1_MSG_MAPID_OFFSET) |
+			((0x8 << MSG_LEN_OFFSET) & MASK_16_27_BIT) |
+			((config << CONFIG_OFFSET) & MASK_8_16_BIT)|
+			version);
+		msg++;
+		*msg = ca_ist_inactivity_timer;
+		msg++;
+		*msg = ca_csc_inactivity_timer;
+		msg_length = L1_NORMAL_MSG;
+	}
+	spin_lock(&fifo->fifo_update_lock);
+	fifo->writer_local_wptr += msg_length;
+	fifo->availablesize -= msg_length;
+	spin_unlock(&fifo->fifo_update_lock);
+}
+
+/**
+ * shm_write_msg_to_fifo() - write message to FIFO
+ * @shrm:	pointer to shrm device information structure
+ * @channel:	audio or common channel
+ * @l2header:	L2 header or device ID
+ * @addr:	pointer to write buffer address
+ * @length:	length of mst to write
+ *
+ * Function Which Writes the data into Fifo in IPC zone
+ * It is called from shm_write_msg. This function will copy the msg
+ * from the kernel buffer to FIFO. There are 4 kernel buffers from where
+ * the data is to copied to FIFO one for each of the messages ISI, RPC,
+ * AUDIO and SECURITY. ISI, RPC and SECURITY messages are pushed to FIFO
+ * in commmon channel and AUDIO message is pushed onto audio channel FIFO.
+ */
+int shm_write_msg_to_fifo(struct shrm_dev *shrm, u8 channel,
+				u8 l2header, void *addr, u32 length)
+{
+	struct fifo_write_params *fifo = NULL;
+	u32 l1_header = 0, l2_header = 0;
+	u32 requiredsize;
+	u32 size = 0;
+	u32 *msg;
+	u8 *src;
+
+	if (channel == COMMON_CHANNEL)
+		fifo = &ape_shm_fifo_0;
+	else if (channel == AUDIO_CHANNEL)
+		fifo = &ape_shm_fifo_1;
+	else {
+		dev_err(shrm->dev, "invalid channel\n");
+		return -EINVAL;
+	}
+
+	/* L2 size in 32b */
+	requiredsize = ((length + 3) / 4);
+	/* Add size of L1 & L2 header */
+	requiredsize += 2;
+
+	/* if availablesize = or < requiredsize then error */
+	if (fifo->availablesize <= requiredsize) {
+		/* Fatal ERROR - should never happens */
+		dev_dbg(shrm->dev, "wr_wptr= %x\n",
+					fifo->writer_local_wptr);
+		dev_dbg(shrm->dev, "wr_rptr= %x\n",
+					fifo->writer_local_rptr);
+		dev_dbg(shrm->dev, "shared_wptr= %x\n",
+						fifo->shared_wptr);
+		dev_dbg(shrm->dev, "shared_rptr= %x\n",
+						fifo->shared_rptr);
+		dev_dbg(shrm->dev, "availsize= %x\n",
+						fifo->availablesize);
+		dev_dbg(shrm->dev, "end__fifo= %x\n",
+				fifo->end_addr_fifo);
+		dev_warn(shrm->dev, "Modem is busy, please wait."
+				" c_cnt = %d; a_cnt = %d\n", msg_common_counter,
+				msg_audio_counter);
+		if (channel == COMMON_CHANNEL) {
+			dev_warn(shrm->dev,
+					"Modem is lagging behind in reading."
+					"Stopping n/w dev queue\n");
+			shrm_stop_netdev(shrm->ndev);
+		}
+
+		return -EAGAIN;
+	}
+
+	if (channel == COMMON_CHANNEL) {
+		/* build L1 header */
+		l1_header = ((L1_NORMAL_MSG << L1_MSG_MAPID_OFFSET) |
+				(((msg_common_counter++) << COUNTER_OFFSET)
+				 & MASK_40_55_BIT) |
+				((length + L2_HEADER_SIZE) & MASK_0_39_BIT));
+	} else if (channel == AUDIO_CHANNEL) {
+		/* build L1 header */
+		l1_header = ((L1_NORMAL_MSG << L1_MSG_MAPID_OFFSET) |
+				(((msg_audio_counter++) << COUNTER_OFFSET)
+				 & MASK_40_55_BIT) |
+				((length + L2_HEADER_SIZE) & MASK_0_39_BIT));
+	}
+
+	/*
+	 * Need to take care race condition for fifo->availablesize
+	 * & fifo->writer_local_rptr with Ac_Read_notification interrupt.
+	 * One option could be use stack variable for LocalRptr and recompute
+	 * fifo->availablesize,based on flag enabled in the
+	 * Ac_read_notification
+	 */
+	l2_header = ((l2header << L2_HEADER_OFFSET) |
+					((length) & MASK_0_39_BIT));
+	/* Check Local Rptr is less than or equal to Local WPtr */
+	if (fifo->writer_local_rptr <= fifo->writer_local_wptr) {
+		msg = (u32 *)
+			(fifo->fifo_virtual_addr+fifo->writer_local_wptr);
+
+		/* check enough place bewteen writer_local_wptr & end of FIFO */
+		if ((fifo->end_addr_fifo-fifo->writer_local_wptr) >=
+							requiredsize) {
+			/* Add L1 header and L2 header */
+			*msg = l1_header;
+			msg++;
+			*msg = l2_header;
+			msg++;
+
+			/* copy the l2 message in 1 memcpy */
+			memcpy((void *)msg, addr, length);
+			/* UpdateWptr */
+			spin_lock_bh(&fifo->fifo_update_lock);
+			fifo->writer_local_wptr += requiredsize;
+			fifo->availablesize -= requiredsize;
+			fifo->writer_local_wptr %= fifo->end_addr_fifo;
+			spin_unlock_bh(&fifo->fifo_update_lock);
+		} else {
+			/*
+			 * message is split between and of FIFO and beg of FIFO
+			 * copy first part from writer_local_wptr to end of FIFO
+			 */
+			size = fifo->end_addr_fifo-fifo->writer_local_wptr;
+
+			if (size == 1) {
+				/* Add L1 header */
+				*msg = l1_header;
+				msg++;
+				spin_lock_bh(&fifo->fifo_update_lock);
+				/* UpdateWptr */
+				fifo->writer_local_wptr = 0;
+				fifo->availablesize -= size;
+				/*
+				 * copy second part from beg of FIFO
+				 * with remaining part of msg
+				 */
+				msg =	(u32 *)
+						fifo->fifo_virtual_addr;
+				*msg = l2_header;
+				msg++;
+
+				/* copy the l3 message in 1 memcpy */
+				memcpy((void *)msg, addr, length);
+				/* UpdateWptr */
+				fifo->writer_local_wptr +=
+							requiredsize-size;
+				fifo->availablesize -=
+							(requiredsize-size);
+				spin_unlock_bh(&fifo->fifo_update_lock);
+			} else if (size == 2) {
+				/* Add L1 header and L2 header */
+				*msg = l1_header;
+				msg++;
+				*msg = l2_header;
+				msg++;
+
+				spin_lock_bh(&fifo->fifo_update_lock);
+				/* UpdateWptr */
+				fifo->writer_local_wptr = 0;
+				fifo->availablesize -= size;
+
+				/*
+				 * copy second part from beg of FIFO
+				 * with remaining part of msg
+				 */
+				msg =	(u32 *)
+						fifo->fifo_virtual_addr;
+				/* copy the l3 message in 1 memcpy */
+				memcpy((void *)msg, addr, length);
+
+				/* UpdateWptr */
+				fifo->writer_local_wptr +=
+							requiredsize-size;
+				fifo->availablesize -=
+							(requiredsize-size);
+				spin_unlock_bh(&fifo->fifo_update_lock);
+			} else {
+				/* Add L1 header and L2 header */
+				*msg = l1_header;
+				msg++;
+				*msg = l2_header;
+				msg++;
+
+				/* copy the l2 message in 1 memcpy */
+				memcpy((void *)msg, addr, (size-2)*4);
+
+				spin_lock_bh(&fifo->fifo_update_lock);
+
+				/* UpdateWptr */
+				fifo->writer_local_wptr = 0;
+				fifo->availablesize -= size;
+
+				/*
+				 * copy second part from beg of FIFO
+				 * with remaining part of msg
+				 */
+				msg = (u32 *)fifo->fifo_virtual_addr;
+				src = (u8 *)addr+((size - 2) * 4);
+				memcpy((void *)msg, src,
+						(length-((size - 2) * 4)));
+
+				/* UpdateWptr */
+				fifo->writer_local_wptr +=
+							requiredsize-size;
+				fifo->availablesize -=
+							(requiredsize-size);
+				spin_unlock_bh(&fifo->fifo_update_lock);
+			}
+
+		}
+	} else {
+		/* writer_local_rptr > writer_local_wptr */
+		msg = (u32 *)
+			(fifo->fifo_virtual_addr+fifo->writer_local_wptr);
+		/* Add L1 header and L2 header */
+		*msg = l1_header;
+		msg++;
+		*msg = l2_header;
+		msg++;
+		/*
+		 * copy message possbile between writer_local_wptr up
+		 * to writer_local_rptr copy the l3 message in 1 memcpy
+		 */
+		memcpy((void *)msg, addr, length);
+
+		spin_lock_bh(&fifo->fifo_update_lock);
+		/* UpdateWptr */
+		fifo->writer_local_wptr += requiredsize;
+		fifo->availablesize -= requiredsize;
+		spin_unlock_bh(&fifo->fifo_update_lock);
+
+	}
+	return length;
+}
+
+/**
+ * read_one_l2msg_common() - read message from common channel
+ * @shrm:	pointer to shrm device information structure
+ * @l2_msg:	pointer to the read L2 message buffer
+ * @len:	message length
+ *
+ * This function read one message from the FIFO  and returns l2 header type
+ */
+u8 read_one_l2msg_common(struct shrm_dev *shrm,
+			u8 *l2_msg, u32 *len)
+{
+	struct fifo_read_params *fifo = &cmt_shm_fifo_0;
+
+	u32 *msg;
+	u32 l1_header = 0;
+	u32 l2_header = 0;
+	u32 length;
+	u8 msgtype;
+	u32 msg_size;
+	u32 size = 0;
+
+	/* Read L1 header read content of reader_local_rptr */
+	msg = (u32 *)
+		(fifo->reader_local_rptr+fifo->fifo_virtual_addr);
+	l1_header = *msg++;
+	msgtype = (l1_header & 0xF0000000) >> L1_HEADER_MASK;
+
+	if (msgtype != L1_NORMAL_MSG) {
+		/* Fatal ERROR - should never happens */
+		dev_dbg(shrm->dev, "wr_wptr= %x\n",
+						fifo->reader_local_wptr);
+		dev_dbg(shrm->dev, "wr_rptr= %x\n",
+						fifo->reader_local_rptr);
+		dev_dbg(shrm->dev, "shared_wptr= %x\n",
+						fifo->shared_wptr);
+		dev_dbg(shrm->dev, "shared_rptr= %x\n",
+						fifo->shared_rptr);
+		dev_dbg(shrm->dev, "availsize= %x\n",
+						fifo->availablesize);
+		dev_dbg(shrm->dev, "end_fifo= %x\n",
+						fifo->end_addr_fifo);
+		/* Fatal ERROR - should never happens */
+		dev_crit(shrm->dev, "Fatal ERROR - should never happen\n");
+		BUG();
+	 }
+	if (fifo->reader_local_rptr == (fifo->end_addr_fifo-1)) {
+		l2_header = (*((u32 *)fifo->fifo_virtual_addr));
+		length = l2_header & MASK_0_39_BIT;
+	} else {
+		/* Read L2 header,Msg size & content of reader_local_rptr */
+		l2_header = *msg;
+		length = l2_header & MASK_0_39_BIT;
+	}
+
+	*len = length;
+	msg_size = ((length + 3) / 4);
+	msg_size += 2;
+
+	if (fifo->reader_local_rptr + msg_size <=
+						fifo->end_addr_fifo) {
+		/* Skip L2 header */
+		msg++;
+
+		/* read msg between reader_local_rptr and end of FIFO */
+		memcpy((void *)l2_msg, (void *)msg, length);
+		/* UpdateLocalRptr */
+		fifo->reader_local_rptr += msg_size;
+		fifo->reader_local_rptr %= fifo->end_addr_fifo;
+	} else {
+		/*
+		 * msg split between end of FIFO and beg copy first
+		 * part of msg read msg between reader_local_rptr
+		 * and end of FIFO
+		 */
+		size = fifo->end_addr_fifo-fifo->reader_local_rptr;
+		if (size == 1) {
+			msg = (u32 *)(fifo->fifo_virtual_addr);
+			/* Skip L2 header */
+			msg++;
+			memcpy((void *)l2_msg, (void *)(msg), length);
+		} else if (size == 2) {
+			/* Skip L2 header */
+			msg++;
+			msg = (u32 *)(fifo->fifo_virtual_addr);
+			memcpy((void *)l2_msg,
+						(void *)(msg), length);
+		} else {
+			/* Skip L2 header */
+			msg++;
+			memcpy((void *)l2_msg, (void *)msg, ((size - 2) * 4));
+			/* copy second part of msg */
+			l2_msg += ((size - 2) * 4);
+			msg = (u32 *)(fifo->fifo_virtual_addr);
+			memcpy((void *)l2_msg, (void *)(msg),
+						(length-((size - 2) * 4)));
+		}
+		fifo->reader_local_rptr =
+			(fifo->reader_local_rptr+msg_size) %
+				fifo->end_addr_fifo;
+	}
+	return (l2_header>>L2_HEADER_OFFSET) & MASK_0_15_BIT;
+ }
+
+u8 read_remaining_messages_common()
+{
+	struct fifo_read_params *fifo = &cmt_shm_fifo_0;
+	/*
+	 * There won't be any Race condition reader_local_rptr &
+	 * fifo->reader_local_wptr with CaMsgpending Notification Interrupt
+	 */
+	return ((fifo->reader_local_rptr != fifo->reader_local_wptr) ? 1 : 0);
+}
+
+u8 read_one_l2msg_audio(struct shrm_dev *shrm,
+				u8 *l2_msg, u32 *len)
+{
+	struct fifo_read_params *fifo = &cmt_shm_fifo_1;
+
+	u32 *msg;
+	u32 l1_header = 0;
+	u32 l2_header = 0;
+	u32 length;
+	u8 msgtype;
+	u32 msg_size;
+	u32 size = 0;
+
+	/* Read L1 header read content of reader_local_rptr */
+	 msg = (u32 *)
+			(fifo->reader_local_rptr+fifo->fifo_virtual_addr);
+	 l1_header = *msg++;
+	 msgtype = (l1_header & 0xF0000000) >> L1_HEADER_MASK;
+
+	if (msgtype != L1_NORMAL_MSG) {
+		/* Fatal ERROR - should never happens */
+		dev_dbg(shrm->dev, "wr_local_wptr= %x\n",
+						fifo->reader_local_wptr);
+		dev_dbg(shrm->dev, "wr_local_rptr= %x\n",
+						fifo->reader_local_rptr);
+		dev_dbg(shrm->dev, "shared_wptr= %x\n",
+						fifo->shared_wptr);
+		dev_dbg(shrm->dev, "shared_rptr= %x\n",
+						fifo->shared_rptr);
+		dev_dbg(shrm->dev, "availsize=%x\n",
+						fifo->availablesize);
+		dev_dbg(shrm->dev, "end_fifo= %x\n",
+						fifo->end_addr_fifo);
+		/* Fatal ERROR - should never happens */
+		dev_crit(shrm->dev, "Fatal ERROR - should never happen\n");
+		BUG();
+	 }
+	if (fifo->reader_local_rptr == (fifo->end_addr_fifo-1)) {
+		l2_header = (*((u32 *)fifo->fifo_virtual_addr));
+		length = l2_header & MASK_0_39_BIT;
+	} else {
+		/* Read L2 header,Msg size & content of reader_local_rptr */
+		l2_header = *msg;
+		length = l2_header & MASK_0_39_BIT;
+	}
+
+	*len = length;
+	msg_size = ((length + 3) / 4);
+	msg_size += 2;
+
+	if (fifo->reader_local_rptr + msg_size <=
+						fifo->end_addr_fifo) {
+		/* Skip L2 header */
+		msg++;
+		/* read msg between reader_local_rptr and end of FIFO */
+		memcpy((void *)l2_msg, (void *)msg, length);
+		/* UpdateLocalRptr */
+		fifo->reader_local_rptr += msg_size;
+		fifo->reader_local_rptr %= fifo->end_addr_fifo;
+	} else {
+
+		/*
+		 * msg split between end of FIFO and beg
+		 * copy first part of msg
+		 * read msg between reader_local_rptr and end of FIFO
+		 */
+		size = fifo->end_addr_fifo-fifo->reader_local_rptr;
+		if (size == 1) {
+			msg = (u32 *)(fifo->fifo_virtual_addr);
+			/* Skip L2 header */
+			msg++;
+			memcpy((void *)l2_msg, (void *)(msg), length);
+		} else if (size == 2) {
+			/* Skip L2 header */
+			msg++;
+			msg = (u32 *)(fifo->fifo_virtual_addr);
+			memcpy((void *)l2_msg, (void *)(msg), length);
+		} else {
+			/* Skip L2 header */
+			msg++;
+			memcpy((void *)l2_msg, (void *)msg, ((size - 2) * 4));
+			/* copy second part of msg */
+			l2_msg += ((size - 2) * 4);
+			msg = (u32 *)(fifo->fifo_virtual_addr);
+			memcpy((void *)l2_msg, (void *)(msg),
+						(length-((size - 2) * 4)));
+		}
+		fifo->reader_local_rptr =
+			(fifo->reader_local_rptr+msg_size) %
+			fifo->end_addr_fifo;
+
+	}
+	return (l2_header>>L2_HEADER_OFFSET) & MASK_0_15_BIT;
+ }
+
+u8 read_remaining_messages_audio()
+{
+	struct fifo_read_params *fifo = &cmt_shm_fifo_1;
+
+	return ((fifo->reader_local_rptr != fifo->reader_local_wptr) ?
+									1 : 0);
+}
+
+u8 is_the_only_one_unread_message(struct shrm_dev *shrm,
+						u8 channel, u32 length)
+{
+	struct fifo_write_params *fifo = NULL;
+	u32 messagesize = 0;
+	u8 is_only_one_unread_msg = 0;
+
+	if (channel == COMMON_CHANNEL)
+		fifo = &ape_shm_fifo_0;
+	else /* channel = AUDIO_CHANNEL */
+		fifo = &ape_shm_fifo_1;
+
+	/* L3 size in 32b */
+	messagesize = ((length + 3) / 4);
+	/* Add size of L1 & L2 header */
+	messagesize += 2;
+	/*
+	 * possibility of race condition with Ac Read notification interrupt.
+	 * need to check ?
+	 */
+	if (fifo->writer_local_wptr > fifo->writer_local_rptr)
+		is_only_one_unread_msg =
+			((fifo->writer_local_rptr + messagesize) ==
+			fifo->writer_local_wptr) ? 1 : 0;
+	else
+		/* Msg split between end of fifo and starting of Fifo */
+		is_only_one_unread_msg =
+			(((fifo->writer_local_rptr + messagesize) %
+			fifo->end_addr_fifo) == fifo->writer_local_wptr) ?
+									1 : 0;
+
+	return is_only_one_unread_msg;
+}
+
+void update_ca_common_local_wptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update CA common reader local write pointer with the
+	 * shared write pointer
+	 */
+	struct fifo_read_params *fifo = &cmt_shm_fifo_0;
+
+	fifo->shared_wptr =
+		(*((u32 *)shrm->ca_common_shared_wptr));
+	fifo->reader_local_wptr = fifo->shared_wptr;
+}
+
+void update_ca_audio_local_wptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update CA audio reader local write pointer with the
+	 * shared write pointer
+	 */
+	struct fifo_read_params *fifo = &cmt_shm_fifo_1;
+
+	fifo->shared_wptr =
+		(*((u32 *)shrm->ca_audio_shared_wptr));
+	fifo->reader_local_wptr = fifo->shared_wptr;
+}
+
+void update_ac_common_local_rptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update AC common writer local read pointer with the
+	 * shared read pointer
+	 */
+	struct fifo_write_params *fifo;
+	u32 free_space = 0;
+
+	fifo = &ape_shm_fifo_0;
+
+	fifo->shared_rptr =
+		(*((u32 *)shrm->ac_common_shared_rptr));
+
+	if (fifo->shared_rptr >= fifo->writer_local_rptr)
+		free_space =
+			(fifo->shared_rptr-fifo->writer_local_rptr);
+	else {
+		free_space =
+			(fifo->end_addr_fifo-fifo->writer_local_rptr);
+		free_space += fifo->shared_rptr;
+	}
+
+	/* Chance of race condition of below variables with write_msg */
+	spin_lock(&fifo->fifo_update_lock);
+	fifo->availablesize += free_space;
+	fifo->writer_local_rptr = fifo->shared_rptr;
+	spin_unlock(&fifo->fifo_update_lock);
+}
+
+void update_ac_audio_local_rptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update AC audio writer local read pointer with the
+	 * shared read pointer
+	 */
+	struct fifo_write_params *fifo;
+	u32 free_space = 0;
+
+	fifo = &ape_shm_fifo_1;
+	fifo->shared_rptr =
+		(*((u32 *)shrm->ac_audio_shared_rptr));
+
+	if (fifo->shared_rptr >= fifo->writer_local_rptr)
+		free_space =
+			(fifo->shared_rptr-fifo->writer_local_rptr);
+	else {
+		free_space =
+			(fifo->end_addr_fifo-fifo->writer_local_rptr);
+		free_space += fifo->shared_rptr;
+	}
+
+	/* Chance of race condition of below variables with write_msg */
+	spin_lock(&fifo->fifo_update_lock);
+	fifo->availablesize += free_space;
+	fifo->writer_local_rptr = fifo->shared_rptr;
+	spin_unlock(&fifo->fifo_update_lock);
+}
+
+void update_ac_common_shared_wptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update AC common shared write pointer with the
+	 * local write pointer
+	 */
+	struct fifo_write_params *fifo;
+
+	fifo = &ape_shm_fifo_0;
+	/* Update shared pointer fifo offset of the IPC zone */
+	(*((u32 *)shrm->ac_common_shared_wptr)) =
+						fifo->writer_local_wptr;
+
+	fifo->shared_wptr = fifo->writer_local_wptr;
+}
+
+void update_ac_audio_shared_wptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update AC audio shared write pointer with the
+	 * local write pointer
+	 */
+	struct fifo_write_params *fifo;
+
+	fifo = &ape_shm_fifo_1;
+	/* Update shared pointer fifo offset of the IPC zone */
+	(*((u32 *)shrm->ac_audio_shared_wptr)) =
+						fifo->writer_local_wptr;
+	fifo->shared_wptr = fifo->writer_local_wptr;
+}
+
+void update_ca_common_shared_rptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update CA common shared read pointer with the
+	 * local read pointer
+	 */
+	struct fifo_read_params *fifo;
+
+	fifo = &cmt_shm_fifo_0;
+
+	/* Update shared pointer fifo offset of the IPC zone */
+	(*((u32 *)shrm->ca_common_shared_rptr)) =
+						fifo->reader_local_rptr;
+	fifo->shared_rptr = fifo->reader_local_rptr;
+}
+
+void update_ca_audio_shared_rptr(struct shrm_dev *shrm)
+{
+	/*
+	 * update CA audio shared read pointer with the
+	 * local read pointer
+	 */
+	struct fifo_read_params *fifo;
+
+	fifo = &cmt_shm_fifo_1;
+
+	/* Update shared pointer fifo offset of the IPC zone */
+	(*((u32 *)shrm->ca_audio_shared_rptr)) =
+						fifo->reader_local_rptr;
+	fifo->shared_rptr = fifo->reader_local_rptr;
+}
+
+void get_reader_pointers(u8 channel_type, u32 *reader_local_rptr,
+				u32 *reader_local_wptr, u32 *shared_rptr)
+{
+	struct fifo_read_params *fifo = NULL;
+
+	if (channel_type == COMMON_CHANNEL)
+		fifo = &cmt_shm_fifo_0;
+	else /* channel_type = AUDIO_CHANNEL */
+		fifo = &cmt_shm_fifo_1;
+
+	*reader_local_rptr = fifo->reader_local_rptr;
+	*reader_local_wptr = fifo->reader_local_wptr;
+	*shared_rptr = fifo->shared_rptr;
+}
+
+void get_writer_pointers(u8 channel_type, u32 *writer_local_rptr,
+			 u32 *writer_local_wptr, u32 *shared_wptr)
+{
+	struct fifo_write_params *fifo = NULL;
+
+	if (channel_type == COMMON_CHANNEL)
+		fifo = &ape_shm_fifo_0;
+	else /* channel_type = AUDIO_CHANNEL */
+		fifo = &ape_shm_fifo_1;
+
+	*writer_local_rptr = fifo->writer_local_rptr;
+	*writer_local_wptr = fifo->writer_local_wptr;
+	*shared_wptr = fifo->shared_wptr;
+}
+
+void set_ca_msg_0_read_notif_send(u8 val)
+{
+	cmt_read_notif_0_send = val;
+}
+
+u8 get_ca_msg_0_read_notif_send(void)
+{
+	return cmt_read_notif_0_send;
+}
+
+void set_ca_msg_1_read_notif_send(u8 val)
+{
+	cmt_read_notif_1_send = val;
+}
+
+u8 get_ca_msg_1_read_notif_send(void)
+{
+	return cmt_read_notif_1_send;
+}
diff --git a/drivers/misc/shrm/shrm_protocol.c b/drivers/misc/shrm/shrm_protocol.c
new file mode 100644
index 00000000000..dd52f9e20ea
--- /dev/null
+++ b/drivers/misc/shrm/shrm_protocol.c
@@ -0,0 +1,1177 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/hrtimer.h>
+#include <linux/delay.h>
+#include <linux/netlink.h>
+#include <linux/workqueue.h>
+
+#include <mach/shrm.h>
+#include <mach/shrm_driver.h>
+#include <mach/shrm_private.h>
+#include <mach/shrm_net.h>
+#include <mach/prcmu-fw-api.h>
+#include <mach/prcmu-regs.h>
+#include <mach/suspend.h>
+
+#define L2_HEADER_ISI		0x0
+#define L2_HEADER_RPC		0x1
+#define L2_HEADER_AUDIO		0x2
+#define L2_HEADER_SECURITY	0x3
+#define L2_HEADER_COMMON_SIMPLE_LOOPBACK	0xC0
+#define L2_HEADER_COMMON_ADVANCED_LOOPBACK	0xC1
+#define L2_HEADER_AUDIO_SIMPLE_LOOPBACK		0x80
+#define L2_HEADER_AUDIO_ADVANCED_LOOPBACK	0x81
+#define MAX_PAYLOAD 1024
+
+static u8 boot_state = BOOT_INIT;
+static u8 recieve_common_msg[8*1024];
+static u8 recieve_audio_msg[8*1024];
+static received_msg_handler rx_common_handler;
+static received_msg_handler rx_audio_handler;
+static struct hrtimer timer;
+static char is_earlydrop;
+struct sock *shrm_nl_sk;
+
+static char shrm_common_tx_state = SHRM_SLEEP_STATE;
+static char shrm_common_rx_state = SHRM_SLEEP_STATE;
+static char shrm_audio_tx_state = SHRM_SLEEP_STATE;
+static char shrm_audio_rx_state = SHRM_SLEEP_STATE;
+
+static atomic_t ac_sleep_disable_count = ATOMIC_INIT(0);
+static struct shrm_dev *shm_dev;
+
+/* Spin lock and tasklet declaration */
+DECLARE_TASKLET(shm_ca_0_tasklet, shm_ca_msgpending_0_tasklet, 0);
+DECLARE_TASKLET(shm_ca_1_tasklet, shm_ca_msgpending_1_tasklet, 0);
+DECLARE_TASKLET(shm_ac_read_0_tasklet, shm_ac_read_notif_0_tasklet, 0);
+DECLARE_TASKLET(shm_ac_read_1_tasklet, shm_ac_read_notif_1_tasklet, 0);
+
+static DEFINE_MUTEX(ac_state_mutex);
+
+static DEFINE_SPINLOCK(ca_common_lock);
+static DEFINE_SPINLOCK(ca_audio_lock);
+static DEFINE_SPINLOCK(ca_wake_req_lock);
+static DEFINE_SPINLOCK(boot_lock);
+
+enum shrm_nl {
+	SHRM_NL_MOD_RESET = 1,
+	SHRM_NL_MOD_QUERY_STATE,
+	SHRM_NL_USER_MOD_RESET,
+	SHRM_NL_STATUS_MOD_ONLINE,
+	SHRM_NL_STATUS_MOD_OFFLINE,
+};
+
+static void shm_ac_sleep_req_work(struct work_struct *work)
+{
+	mutex_lock(&ac_state_mutex);
+	if (atomic_read(&ac_sleep_disable_count) == 0)
+		prcmu_ac_sleep_req();
+	mutex_unlock(&ac_state_mutex);
+}
+
+static u32 get_host_accessport_val(void)
+{
+	u32 prcm_hostaccess;
+
+	prcm_hostaccess = readl(PRCM_HOSTACCESS_REQ);
+	wmb();
+	prcm_hostaccess = prcm_hostaccess & 0x01;
+
+	return prcm_hostaccess;
+}
+static enum hrtimer_restart callback(struct hrtimer *timer)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ca_wake_req_lock, flags);
+	if (((shrm_common_rx_state == SHRM_IDLE) ||
+				(shrm_common_rx_state == SHRM_SLEEP_STATE))
+			&& ((shrm_common_tx_state == SHRM_IDLE) ||
+				(shrm_common_tx_state == SHRM_SLEEP_STATE))
+			&& ((shrm_audio_rx_state == SHRM_IDLE)  ||
+				(shrm_audio_rx_state == SHRM_SLEEP_STATE))
+			&& ((shrm_audio_tx_state == SHRM_IDLE)  ||
+				(shrm_audio_tx_state == SHRM_SLEEP_STATE))) {
+
+		shrm_common_rx_state = SHRM_SLEEP_STATE;
+		shrm_audio_rx_state = SHRM_SLEEP_STATE;
+		shrm_common_tx_state = SHRM_SLEEP_STATE;
+		shrm_audio_tx_state = SHRM_SLEEP_STATE;
+
+		queue_work(shm_dev->shm_ac_sleep_wq,
+				&shm_dev->shm_ac_sleep_req);
+
+	}
+	spin_unlock_irqrestore(&ca_wake_req_lock, flags);
+
+	return HRTIMER_NORESTART;
+}
+
+int nl_send_multicast_message(int msg, gfp_t gfp_mask)
+{
+	struct sk_buff *skb = NULL;
+	struct nlmsghdr *nlh = NULL;
+	int err;
+
+	/* prepare netlink message */
+	skb = alloc_skb(NLMSG_SPACE(MAX_PAYLOAD), gfp_mask);
+	if (!skb) {
+		dev_err(shm_dev->dev, "%s:alloc_skb failed\n", __func__);
+		err = -ENOMEM;
+		goto out;
+	}
+
+	nlh = (struct nlmsghdr *)skb->data;
+	nlh->nlmsg_len = NLMSG_SPACE(MAX_PAYLOAD);
+	dev_dbg(shm_dev->dev, "nlh->nlmsg_len = %d\n", nlh->nlmsg_len);
+
+	nlh->nlmsg_pid = 0;  /* from kernel */
+	nlh->nlmsg_flags = 0;
+	*(int *)NLMSG_DATA(nlh) = msg;
+	skb_put(skb, MAX_PAYLOAD);
+	/* sender is in group 1<<0 */
+	NETLINK_CB(skb).pid = 0;  /* from kernel */
+	/* to mcast group 1<<0 */
+	NETLINK_CB(skb).dst_group = 1;
+
+	/*multicast the message to all listening processes*/
+	err = netlink_broadcast(shrm_nl_sk, skb, 0, 1, gfp_mask);
+	dev_dbg(shm_dev->dev, "ret val from nl-multicast = %d\n", err);
+
+out:
+	return err;
+}
+
+static void nl_send_unicast_message(int dst_pid)
+{
+	struct sk_buff *skb = NULL;
+	struct nlmsghdr *nlh = NULL;
+	int err;
+	int bt_state;
+	unsigned long flags;
+
+	dev_info(shm_dev->dev, "Sending unicast message\n");
+
+	/* prepare the NL message for unicast */
+	skb = alloc_skb(NLMSG_SPACE(MAX_PAYLOAD), GFP_KERNEL);
+	if (!skb) {
+		dev_err(shm_dev->dev, "%s:alloc_skb failed\n", __func__);
+		return;
+	}
+
+	nlh = (struct nlmsghdr *)skb->data;
+	nlh->nlmsg_len = NLMSG_SPACE(MAX_PAYLOAD);
+	dev_dbg(shm_dev->dev, "nlh->nlmsg_len = %d\n", nlh->nlmsg_len);
+
+	nlh->nlmsg_pid = 0;  /* from kernel */
+	nlh->nlmsg_flags = 0;
+
+	spin_lock_irqsave(&boot_lock, flags);
+	bt_state = boot_state;
+	spin_unlock_irqrestore(&boot_lock, flags);
+
+	if (bt_state == BOOT_DONE)
+		*(int *)NLMSG_DATA(nlh) = SHRM_NL_STATUS_MOD_ONLINE;
+	else
+		*(int *)NLMSG_DATA(nlh) = SHRM_NL_STATUS_MOD_OFFLINE;
+
+	skb_put(skb, MAX_PAYLOAD);
+	/* sender is in group 1<<0 */
+	NETLINK_CB(skb).pid = 0;  /* from kernel */
+	NETLINK_CB(skb).dst_group = 0;
+
+	/*unicast the message to the querying processes*/
+	err = netlink_unicast(shrm_nl_sk, skb, dst_pid, MSG_DONTWAIT);
+	dev_dbg(shm_dev->dev, "ret val from nl-unicast = %d\n", err);
+}
+
+
+static int check_modem_in_reset(void)
+{
+	u8 bt_state;
+	unsigned long flags;
+
+	spin_lock_irqsave(&boot_lock, flags);
+	bt_state = boot_state;
+	spin_unlock_irqrestore(&boot_lock, flags);
+
+#ifdef CONFIG_U8500_SHRM_MODEM_SILENT_RESET
+	if (bt_state != BOOT_UNKNOWN)
+		return 0;
+	else
+		return -ENODEV;
+#else
+	/*
+	 * this check won't be applicable and won't work correctly
+	 * if modem-silent-feature is not enabled
+	 * so, simply return 0
+	 */
+	return 0;
+#endif
+}
+
+void shm_ca_msgpending_0_tasklet(unsigned long tasklet_data)
+{
+	struct shrm_dev *shrm = (struct shrm_dev *)tasklet_data;
+	u32 reader_local_rptr;
+	u32 reader_local_wptr;
+	u32 shared_rptr;
+	u32 config = 0, version = 0;
+	unsigned long flags;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	/* Interprocess locking */
+	spin_lock(&ca_common_lock);
+
+	/* Update_reader_local_wptr with shared_wptr */
+	update_ca_common_local_wptr(shrm);
+	get_reader_pointers(COMMON_CHANNEL, &reader_local_rptr,
+				&reader_local_wptr, &shared_rptr);
+
+	set_ca_msg_0_read_notif_send(0);
+
+	if (boot_state == BOOT_DONE) {
+		shrm_common_rx_state = SHRM_PTR_FREE;
+
+		if (reader_local_rptr != shared_rptr)
+			ca_msg_read_notification_0(shrm);
+		if (reader_local_rptr != reader_local_wptr)
+			receive_messages_common(shrm);
+		get_reader_pointers(COMMON_CHANNEL, &reader_local_rptr,
+				&reader_local_wptr, &shared_rptr);
+		if (reader_local_rptr == reader_local_wptr)
+			shrm_common_rx_state = SHRM_IDLE;
+	} else {
+		/* BOOT phase.only a BOOT_RESP should be in FIFO */
+		if (boot_state != BOOT_INFO_SYNC) {
+			if (!read_boot_info_req(shrm, &config, &version)) {
+				dev_err(shrm->dev,
+						"Unable to read boot state\n");
+				BUG();
+			}
+			/* SendReadNotification */
+			ca_msg_read_notification_0(shrm);
+			/*
+			 * Check the version number before
+			 * sending Boot info response
+			 */
+
+			/* send MsgPending notification */
+			write_boot_info_resp(shrm, config, version);
+			spin_lock_irqsave(&boot_lock, flags);
+			boot_state = BOOT_INFO_SYNC;
+			spin_unlock_irqrestore(&boot_lock, flags);
+			dev_info(shrm->dev, "BOOT_INFO_SYNC\n");
+			queue_work(shrm->shm_common_ch_wr_wq,
+					&shrm->send_ac_msg_pend_notify_0);
+		} else {
+			ca_msg_read_notification_0(shrm);
+			dev_info(shrm->dev,
+				"BOOT_INFO_SYNC\n");
+		}
+	}
+	/* Interprocess locking */
+	spin_unlock(&ca_common_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+void shm_ca_msgpending_1_tasklet(unsigned long tasklet_data)
+{
+	struct shrm_dev *shrm = (struct shrm_dev *)tasklet_data;
+	u32 reader_local_rptr;
+	u32 reader_local_wptr;
+	u32 shared_rptr;
+
+	/*
+	 * This function is called when CaMsgPendingNotification Trigerred
+	 * by CMU. It means that CMU has wrote a message into Ca Audio FIFO
+	 */
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown\n",
+				__func__);
+		return;
+	}
+
+	/* Interprocess locking */
+	spin_lock(&ca_audio_lock);
+
+	/* Update_reader_local_wptr(with shared_wptr) */
+	update_ca_audio_local_wptr(shrm);
+	get_reader_pointers(AUDIO_CHANNEL, &reader_local_rptr,
+					&reader_local_wptr, &shared_rptr);
+
+	set_ca_msg_1_read_notif_send(0);
+
+	if (boot_state != BOOT_DONE) {
+		dev_err(shrm->dev, "Boot Error\n");
+		return;
+	}
+	shrm_audio_rx_state = SHRM_PTR_FREE;
+	/* Check we already read the message */
+	if (reader_local_rptr != shared_rptr)
+		ca_msg_read_notification_1(shrm);
+	if (reader_local_rptr != reader_local_wptr)
+		receive_messages_audio(shrm);
+
+	get_reader_pointers(AUDIO_CHANNEL, &reader_local_rptr,
+			&reader_local_wptr, &shared_rptr);
+	if (reader_local_rptr == reader_local_wptr)
+		shrm_audio_rx_state = SHRM_IDLE;
+
+	 /* Interprocess locking */
+	spin_unlock(&ca_audio_lock);
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+void shm_ac_read_notif_0_tasklet(unsigned long tasklet_data)
+{
+	struct shrm_dev *shrm = (struct shrm_dev *)tasklet_data;
+	u32 writer_local_rptr;
+	u32 writer_local_wptr;
+	u32 shared_wptr;
+	unsigned long flags;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	/* Update writer_local_rptrwith shared_rptr */
+	update_ac_common_local_rptr(shrm);
+	get_writer_pointers(COMMON_CHANNEL, &writer_local_rptr,
+				&writer_local_wptr, &shared_wptr);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown\n",
+				__func__);
+		return;
+	}
+
+	if (boot_state == BOOT_INFO_SYNC) {
+		/* BOOT_RESP sent by APE has been received by CMT */
+		spin_lock_irqsave(&boot_lock, flags);
+		boot_state = BOOT_DONE;
+		spin_unlock_irqrestore(&boot_lock, flags);
+		dev_info(shrm->dev, "IPC_ISA BOOT_DONE\n");
+
+		if (shrm->msr_flag) {
+			shrm_start_netdev(shrm->ndev);
+			shrm->msr_flag = 0;
+
+			/* multicast that modem is online */
+			nl_send_multicast_message(SHRM_NL_STATUS_MOD_ONLINE, GFP_ATOMIC);
+		}
+
+	} else if (boot_state == BOOT_DONE) {
+		if (writer_local_rptr != writer_local_wptr) {
+			shrm_common_tx_state = SHRM_PTR_FREE;
+			queue_work(shrm->shm_common_ch_wr_wq,
+					&shrm->send_ac_msg_pend_notify_0);
+		} else {
+			shrm_common_tx_state = SHRM_IDLE;
+			shrm_restart_netdev(shrm->ndev);
+		}
+	} else {
+		dev_err(shrm->dev, "Invalid boot state\n");
+	}
+	/* start timer here */
+	hrtimer_start(&timer, ktime_set(0, 10*NSEC_PER_MSEC),
+			HRTIMER_MODE_REL);
+	atomic_dec(&ac_sleep_disable_count);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+void shm_ac_read_notif_1_tasklet(unsigned long tasklet_data)
+{
+	struct shrm_dev *shrm = (struct shrm_dev *)tasklet_data;
+	u32 writer_local_rptr;
+	u32 writer_local_wptr;
+	u32 shared_wptr;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown\n",
+				__func__);
+		return;
+	}
+
+	/* Update writer_local_rptr(with shared_rptr) */
+	update_ac_audio_local_rptr(shrm);
+	get_writer_pointers(AUDIO_CHANNEL, &writer_local_rptr,
+				&writer_local_wptr, &shared_wptr);
+	if (boot_state != BOOT_DONE) {
+		dev_err(shrm->dev, "Error Case in boot state\n");
+		return;
+	}
+	if (writer_local_rptr != writer_local_wptr) {
+		shrm_audio_tx_state = SHRM_PTR_FREE;
+		queue_work(shrm->shm_audio_ch_wr_wq,
+				&shrm->send_ac_msg_pend_notify_1);
+	} else {
+		shrm_audio_tx_state = SHRM_IDLE;
+	}
+	/* start timer here */
+	hrtimer_start(&timer, ktime_set(0, 10*NSEC_PER_MSEC),
+			HRTIMER_MODE_REL);
+	atomic_dec(&ac_sleep_disable_count);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+void shm_ca_sleep_req_work(struct work_struct *work)
+{
+	dev_dbg(shm_dev->dev, "%s:IRQ_PRCMU_CA_SLEEP\n", __func__);
+
+	shrm_common_rx_state = SHRM_IDLE;
+	shrm_audio_rx_state =  SHRM_IDLE;
+
+	writel((1<<GOP_CA_WAKE_ACK_BIT),
+		shm_dev->intr_base + GOP_SET_REGISTER_BASE);
+
+	hrtimer_start(&timer, ktime_set(0, 10*NSEC_PER_MSEC),
+			HRTIMER_MODE_REL);
+#ifdef CONFIG_UX500_SUSPEND
+	suspend_unblock_sleep();
+#endif
+	atomic_dec(&ac_sleep_disable_count);
+}
+
+void shm_ca_wake_req_work(struct work_struct *work)
+{
+	struct shrm_dev *shrm = container_of(work,
+			struct shrm_dev, shm_ca_wake_req);
+
+	/* initialize the FIFO Variables */
+	if (boot_state == BOOT_INIT)
+		shm_fifo_init(shrm);
+
+	mutex_lock(&ac_state_mutex);
+	prcmu_ac_wake_req();
+	mutex_unlock(&ac_state_mutex);
+
+	/* send ca_wake_ack_interrupt to CMU */
+	if (!get_host_accessport_val())
+		BUG();
+	writel((1<<GOP_CA_WAKE_ACK_BIT),
+			shm_dev->intr_base + GOP_SET_REGISTER_BASE);
+}
+
+static int shrm_modem_reset_sequence(void)
+{
+	int err;
+	unsigned long flags;
+
+	/*
+	 * disable irqs
+	 * very much needed for user-space initiated
+	 * modem-reset
+	 */
+	disable_irq_nosync(shm_dev->ac_read_notif_0_irq);
+	disable_irq_nosync(shm_dev->ac_read_notif_1_irq);
+	disable_irq_nosync(shm_dev->ca_msg_pending_notif_0_irq);
+	disable_irq_nosync(shm_dev->ca_msg_pending_notif_1_irq);
+	disable_irq_nosync(IRQ_PRCMU_CA_WAKE);
+	disable_irq_nosync(IRQ_PRCMU_CA_SLEEP);
+
+
+	/* update the boot_state */
+	spin_lock_irqsave(&boot_lock, flags);
+	boot_state = BOOT_UNKNOWN;
+
+	/*
+	 * put a barrier over here to make sure boot_state is updated
+	 * else, it is seen that some of already executing modem
+	 * irqs or tasklets fail the protocol checks and will ultimately
+	 * try to acces the modem causing system to hang.
+	 * This is particularly seen with user-space initiated modem reset
+	 */
+	wmb();
+	spin_unlock_irqrestore(&boot_lock, flags);
+
+	hrtimer_cancel(&timer);
+
+	/* reset the state for ac-wake LOW logic */
+	atomic_set(&ac_sleep_disable_count, 0);
+
+	/* stop network queue */
+	shrm_stop_netdev(shm_dev->ndev);
+
+	/* reset char device queues */
+	shrm_char_reset_queues(shm_dev);
+
+	/* reset protocol states */
+	shrm_common_tx_state = SHRM_SLEEP_STATE;
+	shrm_common_rx_state = SHRM_SLEEP_STATE;
+	shrm_audio_tx_state = SHRM_SLEEP_STATE;
+	shrm_audio_rx_state = SHRM_SLEEP_STATE;
+
+	/* set the msr flag */
+	shm_dev->msr_flag = 1;
+
+	/* multicast that modem is going to reset */
+	err = nl_send_multicast_message(SHRM_NL_MOD_RESET, GFP_ATOMIC);
+
+	/* reset the boot state */
+	spin_lock_irqsave(&boot_lock, flags);
+	boot_state = BOOT_INIT;
+	spin_unlock_irqrestore(&boot_lock, flags);
+
+	/* re-enable irqs */
+	enable_irq(shm_dev->ac_read_notif_0_irq);
+	enable_irq(shm_dev->ac_read_notif_1_irq);
+	enable_irq(shm_dev->ca_msg_pending_notif_0_irq);
+	enable_irq(shm_dev->ca_msg_pending_notif_1_irq);
+	enable_irq(IRQ_PRCMU_CA_WAKE);
+	enable_irq(IRQ_PRCMU_CA_SLEEP);
+
+	/* reset counter for ac-wake/ac-sleep logic */
+	atomic_set(&ac_sleep_disable_count, 0);
+
+	return err;
+}
+
+static void shrm_modem_reset_callback(unsigned long irq)
+{
+	dev_err(shm_dev->dev, "Received mod_reset_req interrupt\n");
+
+#ifdef CONFIG_U8500_SHRM_MODEM_SILENT_RESET
+	{
+		int err;
+		dev_info(shm_dev->dev, "Initiating Modem silent reset\n");
+
+		err = shrm_modem_reset_sequence();
+		if (err)
+			dev_err(shm_dev->dev,
+				"Failed multicast of modem reset\n");
+	}
+#else
+	dev_info(shm_dev->dev, "Modem in reset loop, doing System reset\n");
+	/* Call the PRCMU reset API */
+	prcmu_system_reset();
+#endif
+}
+
+DECLARE_TASKLET(shrm_sw_reset_callback, shrm_modem_reset_callback,
+		IRQ_PRCMU_MODEM_SW_RESET_REQ);
+
+static irqreturn_t shrm_prcmu_irq_handler(int irq, void *data)
+{
+	struct shrm_dev *shrm = data;
+
+	switch (irq) {
+	case IRQ_PRCMU_CA_WAKE:
+#ifdef CONFIG_UX500_SUSPEND
+		suspend_block_sleep();
+#endif
+		atomic_inc(&ac_sleep_disable_count);
+		queue_work(shrm->shm_ca_wake_wq, &shrm->shm_ca_wake_req);
+		break;
+	case IRQ_PRCMU_CA_SLEEP:
+		queue_work(shrm->shm_ca_wake_wq, &shrm->shm_ca_sleep_req);
+		break;
+	case IRQ_PRCMU_MODEM_SW_RESET_REQ:
+		tasklet_schedule(&shrm_sw_reset_callback);
+		break;
+	default:
+		dev_err(shrm->dev, "%s: => IRQ %d\n", __func__, irq);
+		return IRQ_NONE;
+	}
+	return IRQ_HANDLED;
+}
+
+static void send_ac_msg_pend_notify_0_work(struct work_struct *work)
+{
+	struct shrm_dev *shrm = container_of(work, struct shrm_dev,
+			send_ac_msg_pend_notify_0);
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	update_ac_common_shared_wptr(shrm);
+
+	mutex_lock(&ac_state_mutex);
+	atomic_inc(&ac_sleep_disable_count);
+	prcmu_ac_wake_req();
+	mutex_unlock(&ac_state_mutex);
+
+	if (!get_host_accessport_val())
+		BUG();
+
+	/* Trigger AcMsgPendingNotification to CMU */
+	writel((1<<GOP_COMMON_AC_MSG_PENDING_NOTIFICATION_BIT),
+			shrm->intr_base + GOP_SET_REGISTER_BASE);
+
+	if (shrm_common_tx_state == SHRM_PTR_FREE)
+		shrm_common_tx_state = SHRM_PTR_BUSY;
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+static void send_ac_msg_pend_notify_1_work(struct work_struct *work)
+{
+	struct shrm_dev *shrm = container_of(work, struct shrm_dev,
+			send_ac_msg_pend_notify_1);
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	/* Update shared_wptr with writer_local_wptr) */
+	update_ac_audio_shared_wptr(shrm);
+
+	mutex_lock(&ac_state_mutex);
+	atomic_inc(&ac_sleep_disable_count);
+	prcmu_ac_wake_req();
+	mutex_unlock(&ac_state_mutex);
+
+	if (!get_host_accessport_val())
+		BUG();
+
+	/* Trigger AcMsgPendingNotification to CMU */
+	writel((1<<GOP_AUDIO_AC_MSG_PENDING_NOTIFICATION_BIT),
+			shrm->intr_base + GOP_SET_REGISTER_BASE);
+
+	if (shrm_audio_tx_state == SHRM_PTR_FREE)
+		shrm_audio_tx_state = SHRM_PTR_BUSY;
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+void shm_nl_receive(struct sk_buff *skb)
+{
+	struct nlmsghdr *nlh = NULL;
+	int msg;
+
+	dev_dbg(shm_dev->dev, "Received NL msg from user-space\n");
+
+	nlh = (struct nlmsghdr *)skb->data;
+	msg = *((int *)(NLMSG_DATA(nlh)));
+	switch (msg) {
+	case SHRM_NL_MOD_QUERY_STATE:
+		dev_info(shm_dev->dev, "mod-query-state from user-space\n");
+		nl_send_unicast_message(nlh->nlmsg_pid);
+		break;
+
+	case SHRM_NL_USER_MOD_RESET:
+		dev_info(shm_dev->dev, "user-space inited mod-reset-req\n");
+		dev_info(shm_dev->dev, "PCRMU resets modem\n");
+		prcmu_modem_reset();
+		break;
+
+	default:
+		dev_err(shm_dev->dev, "Invalid NL msg from user-space\n");
+		break;
+	};
+}
+
+int shrm_protocol_init(struct shrm_dev *shrm,
+			received_msg_handler common_rx_handler,
+			received_msg_handler audio_rx_handler)
+{
+	int err;
+
+	shm_dev = shrm;
+	boot_state = BOOT_INIT;
+	dev_info(shrm->dev, "IPC_ISA BOOT_INIT\n");
+	rx_common_handler = common_rx_handler;
+	rx_audio_handler = audio_rx_handler;
+	atomic_set(&ac_sleep_disable_count, 0);
+
+	is_earlydrop = cpu_is_u8500ed();
+	if (is_earlydrop != 0x01) {
+		hrtimer_init(&timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+		timer.function = callback;
+	}
+
+	shrm->shm_common_ch_wr_wq = create_singlethread_workqueue
+		("shm_common_channel_irq");
+	if (!shrm->shm_common_ch_wr_wq) {
+		dev_err(shrm->dev, "failed to create work queue\n");
+		return -ENOMEM;
+	}
+	shrm->shm_audio_ch_wr_wq = create_singlethread_workqueue
+		("shm_audio_channel_irq");
+	if (!shrm->shm_audio_ch_wr_wq) {
+		dev_err(shrm->dev, "failed to create work queue\n");
+		err = -ENOMEM;
+		goto free_wq1;
+	}
+	shrm->shm_ac_wake_wq = create_singlethread_workqueue("shm_ac_wake_req");
+	if (!shrm->shm_ac_wake_wq) {
+		dev_err(shrm->dev, "failed to create work queue\n");
+		err = -ENOMEM;
+		goto free_wq2;
+	}
+	shrm->shm_ca_wake_wq = create_singlethread_workqueue("shm_ca_wake_req");
+	if (!shrm->shm_ac_wake_wq) {
+		dev_err(shrm->dev, "failed to create work queue\n");
+		err = -ENOMEM;
+		goto free_wq3;
+	}
+	shrm->shm_ac_sleep_wq = create_singlethread_workqueue
+						("shm_ac_sleep_req");
+	if (!shrm->shm_ac_sleep_wq) {
+		dev_err(shrm->dev, "failed to create work queue\n");
+		err = -ENOMEM;
+		goto free_wq4;
+	}
+	INIT_WORK(&shrm->send_ac_msg_pend_notify_0,
+			send_ac_msg_pend_notify_0_work);
+	INIT_WORK(&shrm->send_ac_msg_pend_notify_1,
+			send_ac_msg_pend_notify_1_work);
+	INIT_WORK(&shrm->shm_ca_wake_req, shm_ca_wake_req_work);
+	INIT_WORK(&shrm->shm_ca_sleep_req, shm_ca_sleep_req_work);
+	INIT_WORK(&shrm->shm_ac_sleep_req, shm_ac_sleep_req_work);
+
+	/* set tasklet data */
+	shm_ca_0_tasklet.data = (unsigned long)shrm;
+	shm_ca_1_tasklet.data = (unsigned long)shrm;
+
+	err = request_irq(IRQ_PRCMU_CA_SLEEP, shrm_prcmu_irq_handler,
+			IRQF_NO_SUSPEND, "ca-sleep", shrm);
+	if (err < 0) {
+		dev_err(shm_dev->dev, "Failed alloc IRQ_PRCMU_CA_SLEEP.\n");
+		goto free_wq5;
+	}
+
+	err = request_irq(IRQ_PRCMU_CA_WAKE, shrm_prcmu_irq_handler,
+		IRQF_NO_SUSPEND, "ca-wake", shrm);
+	if (err < 0) {
+		dev_err(shm_dev->dev, "Failed alloc IRQ_PRCMU_CA_WAKE.\n");
+		goto drop2;
+	}
+
+	err = request_irq(IRQ_PRCMU_MODEM_SW_RESET_REQ, shrm_prcmu_irq_handler,
+			IRQF_NO_SUSPEND, "modem-sw-reset-req", shrm);
+	if (err < 0) {
+		dev_err(shm_dev->dev,
+				"Failed alloc IRQ_PRCMU_MODEM_SW_RESET_REQ.\n");
+		goto drop1;
+	}
+
+#ifdef CONFIG_U8500_SHRM_MODEM_SILENT_RESET
+	/* init netlink socket for user-space communication */
+	shrm_nl_sk = netlink_kernel_create(NULL, NETLINK_SHRM, 1,
+			shm_nl_receive, NULL, THIS_MODULE);
+
+	if (!shrm_nl_sk) {
+		dev_err(shm_dev->dev, "netlink socket creation failed\n");
+		goto drop;
+	}
+#endif
+
+	return 0;
+
+#ifdef CONFIG_U8500_SHRM_MODEM_SILENT_RESET
+drop:
+	free_irq(IRQ_PRCMU_MODEM_SW_RESET_REQ, NULL);
+#endif
+drop1:
+	free_irq(IRQ_PRCMU_CA_WAKE, NULL);
+drop2:
+	free_irq(IRQ_PRCMU_CA_SLEEP, NULL);
+free_wq5:
+	destroy_workqueue(shrm->shm_ac_sleep_wq);
+free_wq4:
+	destroy_workqueue(shrm->shm_ca_wake_wq);
+free_wq3:
+	destroy_workqueue(shrm->shm_ac_wake_wq);
+free_wq2:
+	destroy_workqueue(shrm->shm_audio_ch_wr_wq);
+free_wq1:
+	destroy_workqueue(shrm->shm_common_ch_wr_wq);
+	return err;
+}
+
+void shrm_protocol_deinit(struct shrm_dev *shrm)
+{
+	free_irq(IRQ_PRCMU_CA_SLEEP, NULL);
+	free_irq(IRQ_PRCMU_CA_WAKE, NULL);
+	free_irq(IRQ_PRCMU_MODEM_SW_RESET_REQ, NULL);
+	flush_scheduled_work();
+	destroy_workqueue(shrm->shm_common_ch_wr_wq);
+	destroy_workqueue(shrm->shm_audio_ch_wr_wq);
+	destroy_workqueue(shrm->shm_ac_wake_wq);
+	destroy_workqueue(shrm->shm_ca_wake_wq);
+	destroy_workqueue(shrm->shm_ac_sleep_wq);
+}
+
+int get_ca_wake_req_state(void)
+{
+	return ((atomic_read(&ac_sleep_disable_count) > 0) ||
+			prcmu_is_ac_wake_requested());
+}
+
+irqreturn_t ca_wake_irq_handler(int irq, void *ctrlr)
+{
+	struct shrm_dev *shrm = ctrlr;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+	/* initialize the FIFO Variables */
+	if (boot_state == BOOT_INIT)
+		shm_fifo_init(shrm);
+
+	dev_dbg(shrm->dev, "Inside ca_wake_irq_handler\n");
+
+	/* Clear the interrupt */
+	writel((1 << GOP_CA_WAKE_REQ_BIT),
+				shrm->intr_base + GOP_CLEAR_REGISTER_BASE);
+
+	/* send ca_wake_ack_interrupt to CMU */
+	writel((1 << GOP_CA_WAKE_ACK_BIT),
+		shrm->intr_base + GOP_SET_REGISTER_BASE);
+
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return IRQ_HANDLED;
+}
+
+
+irqreturn_t ac_read_notif_0_irq_handler(int irq, void *ctrlr)
+{
+	struct shrm_dev *shrm = ctrlr;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	shm_ac_read_0_tasklet.data = (unsigned long)shrm;
+	tasklet_schedule(&shm_ac_read_0_tasklet);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	/* Clear the interrupt */
+	writel((1 << GOP_COMMON_AC_READ_NOTIFICATION_BIT),
+			shrm->intr_base + GOP_CLEAR_REGISTER_BASE);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return IRQ_HANDLED;
+}
+
+irqreturn_t ac_read_notif_1_irq_handler(int irq, void *ctrlr)
+{
+	struct shrm_dev *shrm = ctrlr;
+
+	dev_dbg(shrm->dev, "%s IN+\n", __func__);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	shm_ac_read_1_tasklet.data = (unsigned long)shrm;
+	tasklet_schedule(&shm_ac_read_1_tasklet);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	/* Clear the interrupt */
+	writel((1 << GOP_AUDIO_AC_READ_NOTIFICATION_BIT),
+			shrm->intr_base + GOP_CLEAR_REGISTER_BASE);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return IRQ_HANDLED;
+}
+
+irqreturn_t ca_msg_pending_notif_0_irq_handler(int irq, void *ctrlr)
+{
+	struct shrm_dev *shrm = ctrlr;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	tasklet_schedule(&shm_ca_0_tasklet);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	/* Clear the interrupt */
+	writel((1 << GOP_COMMON_CA_MSG_PENDING_NOTIFICATION_BIT),
+			shrm->intr_base + GOP_CLEAR_REGISTER_BASE);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return IRQ_HANDLED;
+}
+
+irqreturn_t ca_msg_pending_notif_1_irq_handler(int irq, void *ctrlr)
+{
+	struct shrm_dev *shrm = ctrlr;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	tasklet_schedule(&shm_ca_1_tasklet);
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return IRQ_HANDLED;
+	}
+
+	/* Clear the interrupt */
+	writel((1<<GOP_AUDIO_CA_MSG_PENDING_NOTIFICATION_BIT),
+			shrm->intr_base+GOP_CLEAR_REGISTER_BASE);
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return IRQ_HANDLED;
+
+}
+
+/**
+ * shm_write_msg() - write message to shared memory
+ * @shrm:	pointer to the shrm device information structure
+ * @l2_header:	L2 header
+ * @addr:	pointer to the message
+ * @length:	length of the message to be written
+ *
+ * This function is called from net or char interface driver write operation.
+ * Prior to calling this function the message is copied from the user space
+ * buffer to the kernel buffer. This function based on the l2 header routes
+ * the message to the respective channel and FIFO. Then makes a call to the
+ * fifo write function where the message is written to the physical device.
+ */
+int shm_write_msg(struct shrm_dev *shrm, u8 l2_header,
+					void *addr, u32 length)
+{
+	u8 channel = 0;
+	int ret;
+
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (boot_state != BOOT_DONE) {
+		dev_err(shrm->dev,
+				"error after boot done  call this fn\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if ((l2_header == L2_HEADER_ISI) ||
+			(l2_header == L2_HEADER_RPC) ||
+			(l2_header == L2_HEADER_SECURITY) ||
+			(l2_header == L2_HEADER_COMMON_SIMPLE_LOOPBACK) ||
+			(l2_header == L2_HEADER_COMMON_ADVANCED_LOOPBACK)) {
+		channel = 0;
+		if (shrm_common_tx_state == SHRM_SLEEP_STATE)
+			shrm_common_tx_state = SHRM_PTR_FREE;
+		else if (shrm_common_tx_state == SHRM_IDLE)
+			shrm_common_tx_state = SHRM_PTR_FREE;
+
+	} else if ((l2_header == L2_HEADER_AUDIO) ||
+			(l2_header == L2_HEADER_AUDIO_SIMPLE_LOOPBACK) ||
+			(l2_header == L2_HEADER_AUDIO_ADVANCED_LOOPBACK)) {
+		if (shrm_audio_tx_state == SHRM_SLEEP_STATE)
+			shrm_audio_tx_state = SHRM_PTR_FREE;
+		else if (shrm_audio_tx_state == SHRM_IDLE)
+			shrm_audio_tx_state = SHRM_PTR_FREE;
+
+		channel = 1;
+	} else {
+		ret = -ENODEV;
+		goto out;
+	}
+	ret = shm_write_msg_to_fifo(shrm, channel, l2_header, addr, length);
+	if (ret < 0) {
+		dev_err(shrm->dev, "write message to fifo failed\n");
+		return ret;
+	}
+	/*
+	 * notify only if new msg copied is the only unread one
+	 * otherwise it means that reading process is ongoing
+	 */
+	if (is_the_only_one_unread_message(shrm, channel, length)) {
+
+		/* Send Message Pending Noitication to CMT */
+		if (channel == 0)
+			queue_work(shrm->shm_common_ch_wr_wq,
+					&shrm->send_ac_msg_pend_notify_0);
+		else
+			queue_work(shrm->shm_audio_ch_wr_wq,
+					&shrm->send_ac_msg_pend_notify_1);
+
+	}
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+	return 0;
+
+out:
+	return ret;
+}
+
+void ca_msg_read_notification_0(struct shrm_dev *shrm)
+{
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (get_ca_msg_0_read_notif_send() == 0) {
+		update_ca_common_shared_rptr(shrm);
+
+		if (check_modem_in_reset()) {
+			dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+					__func__);
+			return;
+		}
+
+		/* Trigger CaMsgReadNotification to CMU */
+		writel((1 << GOP_COMMON_CA_READ_NOTIFICATION_BIT),
+			shrm->intr_base + GOP_SET_REGISTER_BASE);
+		set_ca_msg_0_read_notif_send(1);
+		shrm_common_rx_state = SHRM_PTR_BUSY;
+	}
+
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+void ca_msg_read_notification_1(struct shrm_dev *shrm)
+{
+	dev_dbg(shrm->dev, "%s IN\n", __func__);
+
+	if (get_ca_msg_1_read_notif_send() == 0) {
+		update_ca_audio_shared_rptr(shrm);
+
+		if (check_modem_in_reset()) {
+			dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+					__func__);
+			return;
+		}
+
+		/* Trigger CaMsgReadNotification to CMU */
+		writel((1<<GOP_AUDIO_CA_READ_NOTIFICATION_BIT),
+			shrm->intr_base+GOP_SET_REGISTER_BASE);
+		set_ca_msg_1_read_notif_send(1);
+		shrm_audio_rx_state = SHRM_PTR_BUSY;
+	}
+	dev_dbg(shrm->dev, "%s OUT\n", __func__);
+}
+
+/**
+ * receive_messages_common - receive common channnel msg from
+ * CMT(Cellular Mobile Terminal)
+ * @shrm:	pointer to shrm device information structure
+ *
+ * The messages sent from CMT to APE are written to the respective FIFO
+ * and an interrupt is triggered by the CMT. This ca message pending
+ * interrupt calls this function. This function sends a read notification
+ * acknowledgement to the CMT and calls the common channel receive handler
+ * where the messsage is copied to the respective(ISI, RPC, SECURIT) queue
+ * based on the message l2 header.
+ */
+void receive_messages_common(struct shrm_dev *shrm)
+{
+	u8 l2_header;
+	u32 len;
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return;
+	}
+
+	l2_header = read_one_l2msg_common(shrm, recieve_common_msg, &len);
+	/* Send Recieve_Call_back to Upper Layer */
+	if (!rx_common_handler) {
+		dev_err(shrm->dev, "common_rx_handler is Null\n");
+		BUG();
+	}
+	(*rx_common_handler)(l2_header, &recieve_common_msg, len,
+					shrm);
+	/* SendReadNotification */
+	ca_msg_read_notification_0(shrm);
+
+	while (read_remaining_messages_common()) {
+		if (check_modem_in_reset()) {
+			dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+					__func__);
+			return;
+		}
+
+		l2_header = read_one_l2msg_common(shrm, recieve_common_msg,
+								&len);
+		/* Send Recieve_Call_back to Upper Layer */
+		(*rx_common_handler)(l2_header,
+					&recieve_common_msg, len,
+					shrm);
+	}
+}
+
+/**
+ * receive_messages_audio() - receive audio message from CMT
+ * @shrm:	pointer to shrm device information structure
+ *
+ * The messages sent from CMT to APE are written to the respective FIFO
+ * and an interrupt is triggered by the CMT. This ca message pending
+ * interrupt calls this function. This function sends a read notification
+ * acknowledgement to the CMT and calls the common channel receive handler
+ * where the messsage is copied to the audio queue.
+ */
+void receive_messages_audio(struct shrm_dev *shrm)
+{
+	u8 l2_header;
+	u32 len;
+
+	if (check_modem_in_reset()) {
+		dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+				__func__);
+		return;
+	}
+
+	l2_header = read_one_l2msg_audio(shrm, recieve_audio_msg, &len);
+	/* Send Recieve_Call_back to Upper Layer */
+
+	if (!rx_audio_handler) {
+		dev_crit(shrm->dev, "audio_rx_handler is Null\n");
+		BUG();
+	}
+	(*rx_audio_handler)(l2_header, &recieve_audio_msg,
+					len, shrm);
+
+	/* SendReadNotification */
+	ca_msg_read_notification_1(shrm);
+	while (read_remaining_messages_audio())	{
+		if (check_modem_in_reset()) {
+			dev_err(shrm->dev, "%s:Modem state reset or unknown.\n",
+					__func__);
+			return;
+		}
+
+		l2_header = read_one_l2msg_audio(shrm,
+						recieve_audio_msg, &len);
+		/* Send Recieve_Call_back to Upper Layer */
+		(*rx_audio_handler)(l2_header,
+					&recieve_audio_msg, len,
+					shrm);
+	}
+}
+
+u8 get_boot_state()
+{
+	return boot_state;
+}
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index a6b8ce11a22..c1d8099a34e 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -70,3 +70,7 @@ obj-$(CONFIG_USB_IPHETH)        += usb/
 obj-$(CONFIG_USB_CDC_PHONET)   += usb/
 
 obj-$(CONFIG_HYPERV_NET) += hyperv/
+
+ifdef CONFIG_PHONET
+obj-$(CONFIG_U8500_SHRM) += u8500_shrm.o
+endif
diff --git a/drivers/net/u8500_shrm.c b/drivers/net/u8500_shrm.c
new file mode 100644
index 00000000000..55983a59761
--- /dev/null
+++ b/drivers/net/u8500_shrm.c
@@ -0,0 +1,336 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2009
+ *
+ * Author: Biju Das <biju.das@stericsson.com> for ST-Ericsson
+ * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com> for ST-Ericsson
+ * Author: Arun Murthy <arun.murthy@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/if_ether.h>
+#include <linux/netdevice.h>
+#include <linux/phonet.h>
+#include <linux/if_phonet.h>
+#include <linux/if_arp.h>
+#include <net/sock.h>
+#include <net/phonet/phonet.h>
+#include <net/phonet/pep.h>
+
+#include <mach/shrm_driver.h>
+#include <mach/shrm_private.h>
+#include <mach/shrm_config.h>
+#include <mach/shrm_net.h>
+#include <mach/shrm.h>
+
+static u8 wr_isi_msg[10*1024];
+
+/**
+ * shrm_net_receive() - receive data and copy to user space buffer
+ * @dev:	pointer to the network device structure
+ * @data:	pointer to the receive buffer
+ *
+ * Copy data from ISI queue to the user space buffer.
+ */
+int shrm_net_receive(struct net_device *dev, u8 *data)
+{
+	struct sk_buff *skb;
+	struct isadev_context *isadev;
+	struct message_queue *q;
+	u32 msgsize;
+	u32 size = 0;
+	struct shrm_net_iface_priv *net_iface_priv =
+		(struct shrm_net_iface_priv *)netdev_priv(dev);
+	struct shrm_dev *shrm = net_iface_priv->shrm_device;
+
+	if (data == NULL)
+		goto out;
+
+	isadev = &shrm->isa_context->isadev[ISI_MESSAGING];
+	q = &isadev->dl_queue;
+
+	spin_lock_bh(&q->update_lock);
+	if (list_empty(&q->msg_list)) {
+		spin_unlock_bh(&q->update_lock);
+		dev_dbg(shrm->dev, "Empty Shrm queue\n");
+		return 0;
+	}
+	spin_unlock_bh(&q->update_lock);
+
+	msgsize = get_size_of_new_msg(q);
+	if (msgsize <= 0)
+		return msgsize;
+
+	if ((q->readptr+msgsize) >= q->size) {
+		size = (q->size-q->readptr);
+		/*Copy First Part of msg*/
+		memcpy(data,
+			(u8 *)(q->fifo_base + q->readptr), size);
+		/*Copy Second Part of msg at the top of fifo*/
+		memcpy(data+size,
+			(u8 *)(q->fifo_base), (msgsize - size));
+	} else {
+		memcpy(data,
+			(u8 *)(q->fifo_base+q->readptr), msgsize);
+	}
+
+	spin_lock_bh(&q->update_lock);
+	remove_msg_from_queue(q);
+	spin_unlock_bh(&q->update_lock);
+
+	dev_dbg(shrm->dev, "Data len at shrm_net_receive: %d\n", msgsize);
+
+	/*
+	 * The packet has been retrieved from the transmission
+	 * medium. Build an skb around it, so upper layers can handle it
+	 */
+
+	skb = dev_alloc_skb(msgsize);
+	if (!skb) {
+		if (printk_ratelimit())
+			dev_notice(shrm->dev,
+			"isa rx: low on mem - packet dropped\n");
+		dev->stats.rx_dropped++;
+		goto out;
+	}
+	skb_copy_to_linear_data(skb, data, msgsize);
+	skb_put(skb, msgsize);
+	skb_reset_mac_header(skb);
+	__skb_pull(skb, dev->hard_header_len);
+	/*Write metadata, and then pass to the receive level*/
+	skb->dev = dev;/*kmalloc(sizeof(struct net_device), GFP_ATOMIC);*/
+	skb->protocol = htons(ETH_P_PHONET);
+	skb->priority = 0;
+	skb->ip_summed = CHECKSUM_UNNECESSARY; /* don't check it */
+	if (likely(netif_rx_ni(skb) == NET_RX_SUCCESS)) {
+		dev->stats.rx_packets++;
+		dev->stats.rx_bytes += msgsize;
+	} else
+		dev->stats.rx_dropped++;
+
+	return msgsize;
+out:
+	return -ENOMEM;
+}
+
+static int netdev_isa_open(struct net_device *dev)
+{
+	struct shrm_net_iface_priv *net_iface_priv =
+			(struct shrm_net_iface_priv *)netdev_priv(dev);
+	struct shrm_dev *shrm = net_iface_priv->shrm_device;
+
+	shrm->netdev_flag_up = 1;
+	if (!netif_carrier_ok(dev))
+		netif_carrier_on(dev);
+	netif_wake_queue(dev);
+	return 0;
+}
+
+static int netdev_isa_close(struct net_device *dev)
+{
+	struct shrm_net_iface_priv *net_iface_priv =
+			(struct shrm_net_iface_priv *)netdev_priv(dev);
+	struct shrm_dev *shrm = net_iface_priv->shrm_device;
+
+	shrm->netdev_flag_up = 0;
+	netif_stop_queue(dev);
+	netif_carrier_off(dev);
+	return 0;
+}
+
+static int netdev_isa_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	struct if_phonet_req *req = (struct if_phonet_req *)ifr;
+
+	switch (cmd) {
+	case SIOCPNGAUTOCONF:
+		req->ifr_phonet_autoconf.device = PN_DEV_HOST;
+		return 0;
+	}
+	return -ENOIOCTLCMD;
+}
+
+static struct net_device_stats *netdev_isa_stats(struct net_device *dev)
+{
+	return &dev->stats;
+}
+
+/**
+ * netdev_isa_write() - write through the net interface
+ * @skb:	pointer to the socket buffer
+ * @dev:	pointer to the network device structure
+ *
+ * Copies data(ISI message) from the user buffer to the kernel buffer and
+ * schedule transfer thread to transmit the message to the modem via FIFO.
+ */
+static netdev_tx_t netdev_isa_write(struct sk_buff *skb, struct net_device *dev)
+{
+	int err;
+	int retval = 0;
+	struct shrm_net_iface_priv *net_iface_priv =
+			(struct shrm_net_iface_priv *)netdev_priv(dev);
+	struct shrm_dev *shrm = net_iface_priv->shrm_device;
+
+	/*
+	 * FIXME:
+	 * U8500 modem requires that Pipe created/enabled Indication should
+	 * be sent from the port corresponding to GPRS socket.
+	 * Also, the U8500 modem does not implement Pipe controller
+	 * which takes care of port manipulations for GPRS traffic.
+	 *
+	 * Now, APE has GPRS socket and the socket for sending
+	 * Indication msgs bound to different ports.
+	 * Phonet stack does not allow an indication msg to be sent
+	 * from GPRS socket, since Phonet stack assumes the presence
+	 * of Pipe controller in modem.
+	 *
+	 * So, due to lack of Pipe controller implementation in the
+	 * U8500 modem, carry out the port manipulation related to
+	 * GPRS traffic here.
+	 * Ideally, it should be done either by Pipe controller in
+	 * modem OR some implementation of Pipe controller on APE side
+	 */
+	if (skb->data[RESOURCE_ID_INDEX] == PN_PIPE) {
+		if ((skb->data[MSG_ID_INDEX] == PNS_PIPE_CREATED_IND) ||
+			(skb->data[MSG_ID_INDEX] == PNS_PIPE_ENABLED_IND) ||
+			(skb->data[MSG_ID_INDEX] == PNS_PIPE_DISABLED_IND))
+			skb->data[SRC_OBJ_INDEX] = skb->data[PIPE_HDL_INDEX];
+	}
+
+	if ((void *)wr_isi_msg !=
+			memcpy((void *)wr_isi_msg, skb->data, skb->len)) {
+		dev_err(shrm->dev, "memcpy failed\n");
+		dev_kfree_skb(skb);
+		return -EFAULT;
+	}
+
+	spin_lock_bh(&shrm->isa_context->common_tx);
+	err = shm_write_msg(shrm, ISI_MESSAGING, (void *)wr_isi_msg,
+			skb->len);
+	if (!err) {
+		dev->stats.tx_packets++;
+		dev->stats.tx_bytes += skb->len;
+		retval = NETDEV_TX_OK;
+		dev_kfree_skb(skb);
+	} else {
+		dev->stats.tx_dropped++;
+		retval = NETDEV_TX_BUSY;
+	}
+	spin_unlock_bh(&shrm->isa_context->common_tx);
+
+	return retval;
+}
+
+static const struct net_device_ops shrm_netdev_ops = {
+	.ndo_open = netdev_isa_open,
+	.ndo_stop = netdev_isa_close,
+	.ndo_do_ioctl = netdev_isa_ioctl,
+	.ndo_start_xmit = netdev_isa_write,
+	.ndo_get_stats = netdev_isa_stats,
+};
+
+static void shm_net_init(struct net_device *dev)
+{
+	struct shrm_net_iface_priv *net_iface_priv;
+
+	dev->netdev_ops = &shrm_netdev_ops;
+	dev->header_ops = &phonet_header_ops;
+	dev->type = ARPHRD_PHONET;
+	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+	dev->mtu = PHONET_MAX_MTU;
+	dev->hard_header_len = SHRM_HLEN;
+	dev->addr_len = PHONET_ALEN;
+	dev->tx_queue_len = PN_TX_QUEUE_LEN;
+	dev->destructor = free_netdev;
+	dev->dev_addr[0] = PN_LINK_ADDR;
+	net_iface_priv = netdev_priv(dev);
+	memset(net_iface_priv, 0 , sizeof(struct shrm_net_iface_priv));
+}
+
+int shrm_register_netdev(struct shrm_dev *shrm)
+{
+	struct net_device *nw_device;
+	struct shrm_net_iface_priv *net_iface_priv;
+	char *devname = "shrm%d";
+	int err;
+
+	/* allocate the net device */
+	nw_device = shrm->ndev = alloc_netdev(
+			sizeof(struct shrm_net_iface_priv),
+			devname, shm_net_init);
+	if (nw_device == NULL) {
+		dev_err(shrm->dev, "Failed to allocate SHRM Netdev\n");
+		return -ENOMEM;
+	}
+	err = register_netdev(shrm->ndev);
+	if (err) {
+		dev_err(shrm->dev, "Err %i in reg shrm-netdev\n", err);
+		free_netdev(shrm->ndev);
+		return -ENODEV;
+	}
+	dev_info(shrm->dev, "Registered shrm netdev\n");
+
+	net_iface_priv = (struct shrm_net_iface_priv *)netdev_priv(nw_device);
+	net_iface_priv->shrm_device = shrm;
+	net_iface_priv->iface_num = 0;
+
+	return err;
+}
+
+int shrm_stop_netdev(struct net_device *dev)
+{
+	struct shrm_net_iface_priv *net_iface_priv =
+			(struct shrm_net_iface_priv *)netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	return 0;
+}
+
+int shrm_restart_netdev(struct net_device *dev)
+{
+	struct shrm_net_iface_priv *net_iface_priv =
+			(struct shrm_net_iface_priv *)netdev_priv(dev);
+
+	if (netif_queue_stopped(dev))
+		netif_wake_queue(dev);
+	return 0;
+}
+
+int shrm_start_netdev(struct net_device *dev)
+{
+	struct shrm_net_iface_priv *net_iface_priv =
+			(struct shrm_net_iface_priv *)netdev_priv(dev);
+	struct shrm_dev *shrm = net_iface_priv->shrm_device;
+
+	if (!netif_carrier_ok(dev))
+		netif_carrier_on(dev);
+	netif_start_queue(dev);
+	shrm->netdev_flag_up = 1;
+	return 0;
+}
+
+int shrm_suspend_netdev(struct net_device *dev)
+{
+	if (netif_running(dev)) {
+		netif_stop_queue(dev);
+		netif_carrier_off(dev);
+	}
+	netif_device_detach(dev);
+
+	return 0;
+}
+
+int shrm_resume_netdev(struct net_device *dev)
+{
+	netif_device_attach(dev);
+	if (netif_running(dev)) {
+		netif_carrier_on(dev);
+		netif_wake_queue(dev);
+	}
+
+	return 0;
+}
+
+void shrm_unregister_netdev(struct shrm_dev *shrm)
+{
+	unregister_netdev(shrm->ndev);
+}