HSI: omap_ssi: Introducing OMAP SSI driver

Introduces the OMAP SSI driver in the kernel.

The Synchronous Serial Interface (SSI) is a legacy version
of HSI. As in the case of HSI, it is mainly used to connect
Application engines (APE) with cellular modem engines (CMT)
in cellular handsets.

It provides a multichannel, full-duplex, multi-core communication
with no reference clock. The OMAP SSI block is capable of reaching
speeds of 110 Mbit/s.

Change-Id: Iea002a8f321cf66ab439552620af001206626ed6
Signed-off-by: Carlos Chinea <carlos.chinea@nokia.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/20576
Reviewed-by: Pawel SZYSZUK <pawel.szyszuk@stericsson.com>
Tested-by: Pawel SZYSZUK <pawel.szyszuk@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>

2 files changed, 338 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/ssi.c b/arch/arm/mach-omap2/ssi.c
new file mode 100644
index 00000000000..e822a77f5ca
--- /dev/null
+++ b/arch/arm/mach-omap2/ssi.c
@@ -0,0 +1,134 @@
+/*
+ * linux/arch/arm/mach-omap2/ssi.c
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <plat/omap-pm.h>
+#include <plat/ssi.h>
+
+static struct omap_ssi_platform_data ssi_pdata = {
+	.num_ports			= SSI_NUM_PORTS,
+	.get_dev_context_loss_count	= omap_pm_get_dev_context_loss_count,
+};
+
+static struct resource ssi_resources[] = {
+	/* SSI controller */
+	[0] = {
+		.start	= 0x48058000,
+		.end	= 0x48058fff,
+		.name	= "omap_ssi_sys",
+		.flags	= IORESOURCE_MEM,
+	},
+	/* GDD */
+	[1] = {
+		.start	= 0x48059000,
+		.end	= 0x48059fff,
+		.name	= "omap_ssi_gdd",
+		.flags	= IORESOURCE_MEM,
+	},
+	[2] = {
+		.start	= 71,
+		.end	= 71,
+		.name	= "ssi_gdd",
+		.flags	= IORESOURCE_IRQ,
+	},
+	/* SSI port 1 */
+	[3] = {
+		.start	= 0x4805a000,
+		.end	= 0x4805a7ff,
+		.name	= "omap_ssi_sst1",
+		.flags	= IORESOURCE_MEM,
+	},
+	[4] = {
+		.start	= 0x4805a800,
+		.end	= 0x4805afff,
+		.name	= "omap_ssi_ssr1",
+		.flags	= IORESOURCE_MEM,
+	},
+	[5] = {
+		.start	= 67,
+		.end	= 67,
+		.name	= "ssi_p1_mpu_irq0",
+		.flags	= IORESOURCE_IRQ,
+	},
+	[6] = {
+		.start	= 68,
+		.end	= 68,
+		.name	= "ssi_p1_mpu_irq1",
+		.flags	= IORESOURCE_IRQ,
+	},
+	[7] = {
+		.start	= 0,
+		.end	= 0,
+		.name	= "ssi_p1_cawake",
+		.flags	= IORESOURCE_IRQ | IORESOURCE_UNSET,
+	},
+};
+
+static struct platform_device ssi_pdev = {
+	.name		= "omap_ssi",
+	.id		= 0,
+	.num_resources	= ARRAY_SIZE(ssi_resources),
+	.resource	= ssi_resources,
+	.dev		= {
+				.platform_data	= &ssi_pdata,
+	},
+};
+
+int __init omap_ssi_config(struct omap_ssi_board_config *ssi_config)
+{
+	unsigned int port, offset, cawake_gpio;
+	int err;
+
+	ssi_pdata.num_ports = ssi_config->num_ports;
+	for (port = 0, offset = 7; port < ssi_config->num_ports;
+							port++, offset += 5) {
+		cawake_gpio = ssi_config->cawake_gpio[port];
+		if (!cawake_gpio)
+			continue; /* Nothing to do */
+		err = gpio_request(cawake_gpio, "cawake");
+		if (err < 0)
+			goto rback;
+		gpio_direction_input(cawake_gpio);
+		ssi_resources[offset].start = gpio_to_irq(cawake_gpio);
+		ssi_resources[offset].flags &= ~IORESOURCE_UNSET;
+		ssi_resources[offset].flags |= IORESOURCE_IRQ_HIGHEDGE |
+							IORESOURCE_IRQ_LOWEDGE;
+	}
+
+	return 0;
+rback:
+	dev_err(&ssi_pdev.dev, "Request cawake (gpio%d) failed\n", cawake_gpio);
+	while (port > 0)
+		gpio_free(ssi_config->cawake_gpio[--port]);
+
+	return err;
+}
+
+static int __init ssi_init(void)
+{
+	return platform_device_register(&ssi_pdev);
+}
+subsys_initcall(ssi_init);
diff --git a/arch/arm/plat-omap/include/plat/ssi.h b/arch/arm/plat-omap/include/plat/ssi.h
new file mode 100644
index 00000000000..eb84c3a69f7
--- /dev/null
+++ b/arch/arm/plat-omap/include/plat/ssi.h
@@ -0,0 +1,204 @@
+/*
+ * plat/ssi.h
+ *
+ * Hardware definitions for SSI.
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ *
+ * Contact: Carlos Chinea <carlos.chinea@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __OMAP_SSI_REGS_H__
+#define __OMAP_SSI_REGS_H__
+
+#define SSI_NUM_PORTS	1
+/*
+ * SSI SYS registers
+ */
+#define SSI_REVISION_REG		0
+#	define SSI_REV_MAJOR		0xf0
+#	define SSI_REV_MINOR		0xf
+#define SSI_SYSCONFIG_REG		0x10
+#	define SSI_AUTOIDLE		(1 << 0)
+#	define SSI_SOFTRESET		(1 << 1)
+#	define SSI_SIDLEMODE_FORCE	0
+#	define SSI_SIDLEMODE_NO		(1 << 3)
+#	define SSI_SIDLEMODE_SMART	(1 << 4)
+#	define SSI_SIDLEMODE_MASK	0x18
+#	define SSI_MIDLEMODE_FORCE	0
+#	define SSI_MIDLEMODE_NO		(1 << 12)
+#	define SSI_MIDLEMODE_SMART	(1 << 13)
+#	define SSI_MIDLEMODE_MASK	0x3000
+#define SSI_SYSSTATUS_REG		0x14
+#	define SSI_RESETDONE		1
+#define SSI_MPU_STATUS_REG(port, irq)	(0x808 + ((port) * 0x10) + ((irq) * 2))
+#define SSI_MPU_ENABLE_REG(port, irq)	(0x80c + ((port) * 0x10) + ((irq) * 8))
+#	define SSI_DATAACCEPT(channel)		(1 << (channel))
+#	define SSI_DATAAVAILABLE(channel)	(1 << ((channel) + 8))
+#	define SSI_DATAOVERRUN(channel)		(1 << ((channel) + 16))
+#	define SSI_ERROROCCURED			(1 << 24)
+#	define SSI_BREAKDETECTED		(1 << 25)
+#define SSI_GDD_MPU_IRQ_STATUS_REG	0x0800
+#define SSI_GDD_MPU_IRQ_ENABLE_REG	0x0804
+#	define SSI_GDD_LCH(channel)	(1 << (channel))
+#define SSI_WAKE_REG(port)		(0xc00 + ((port) * 0x10))
+#define SSI_CLEAR_WAKE_REG(port)	(0xc04 + ((port) * 0x10))
+#define SSI_SET_WAKE_REG(port)		(0xc08 + ((port) * 0x10))
+#	define SSI_WAKE(channel)	(1 << (channel))
+#	define SSI_WAKE_MASK		0xff
+
+/*
+ * SSI SST registers
+ */
+#define SSI_SST_ID_REG			0
+#define SSI_SST_MODE_REG		4
+#	define SSI_MODE_VAL_MASK	3
+#	define SSI_MODE_SLEEP		0
+#	define SSI_MODE_STREAM		1
+#	define SSI_MODE_FRAME		2
+#	define SSI_MODE_MULTIPOINTS	3
+#define SSI_SST_FRAMESIZE_REG		8
+#	define SSI_FRAMESIZE_DEFAULT	31
+#define SSI_SST_TXSTATE_REG		0xc
+#	define	SSI_TXSTATE_IDLE	0
+#define SSI_SST_BUFSTATE_REG		0x10
+#	define	SSI_FULL(channel)	(1 << (channel))
+#define SSI_SST_DIVISOR_REG		0x18
+#	define SSI_MAX_DIVISOR		127
+#define SSI_SST_BREAK_REG		0x20
+#define SSI_SST_CHANNELS_REG		0x24
+#	define SSI_CHANNELS_DEFAULT	4
+#define SSI_SST_ARBMODE_REG		0x28
+#	define SSI_ARBMODE_ROUNDROBIN	0
+#	define SSI_ARBMODE_PRIORITY	1
+#define SSI_SST_BUFFER_CH_REG(channel)	(0x80 + ((channel) * 4))
+#define SSI_SST_SWAPBUF_CH_REG(channel)	(0xc0 + ((channel) * 4))
+
+/*
+ * SSI SSR registers
+ */
+#define SSI_SSR_ID_REG			0
+#define SSI_SSR_MODE_REG		4
+#define SSI_SSR_FRAMESIZE_REG		8
+#define SSI_SSR_RXSTATE_REG		0xc
+#define SSI_SSR_BUFSTATE_REG		0x10
+#	define SSI_NOTEMPTY(channel)	(1 << (channel))
+#define SSI_SSR_BREAK_REG		0x1c
+#define SSI_SSR_ERROR_REG		0x20
+#define SSI_SSR_ERRORACK_REG		0x24
+#define SSI_SSR_OVERRUN_REG		0x2c
+#define SSI_SSR_OVERRUNACK_REG		0x30
+#define SSI_SSR_TIMEOUT_REG		0x34
+#	define SSI_TIMEOUT_DEFAULT	0
+#define SSI_SSR_CHANNELS_REG		0x28
+#define SSI_SSR_BUFFER_CH_REG(channel)	(0x80 + ((channel) * 4))
+#define SSI_SSR_SWAPBUF_CH_REG(channel)	(0xc0 + ((channel) * 4))
+
+/*
+ * SSI GDD registers
+ */
+#define SSI_GDD_HW_ID_REG		0
+#define SSI_GDD_PPORT_ID_REG		0x10
+#define SSI_GDD_MPORT_ID_REG		0x14
+#define SSI_GDD_PPORT_SR_REG		0x20
+#define SSI_GDD_MPORT_SR_REG		0x24
+#	define SSI_ACTIVE_LCH_NUM_MASK	0xff
+#define SSI_GDD_TEST_REG		0x40
+#	define SSI_TEST			1
+#define SSI_GDD_GCR_REG			0x100
+#	define	SSI_CLK_AUTOGATING_ON	(1 << 3)
+#	define	SSI_FREE		(1 << 2)
+#	define	SSI_SWITCH_OFF		(1 << 0)
+#define SSI_GDD_GRST_REG		0x200
+#	define SSI_SWRESET		1
+#define SSI_GDD_CSDP_REG(channel)	(0x800 + ((channel) * 0x40))
+#	define SSI_DST_BURST_EN_MASK	0xc000
+#	define SSI_DST_SINGLE_ACCESS0	0
+#	define SSI_DST_SINGLE_ACCESS	(1 << 14)
+#	define SSI_DST_BURST_4x32_BIT	(2 << 14)
+#	define SSI_DST_BURST_8x32_BIT	(3 << 14)
+#	define SSI_DST_MASK		0x1e00
+#	define SSI_DST_MEMORY_PORT	(8 << 9)
+#	define SSI_DST_PERIPHERAL_PORT	(9 << 9)
+#	define SSI_SRC_BURST_EN_MASK	0x180
+#	define SSI_SRC_SINGLE_ACCESS0	0
+#	define SSI_SRC_SINGLE_ACCESS	(1 << 7)
+#	define SSI_SRC_BURST_4x32_BIT	(2 << 7)
+#	define SSI_SRC_BURST_8x32_BIT	(3 << 7)
+#	define SSI_SRC_MASK		0x3c
+#	define SSI_SRC_MEMORY_PORT	(8 << 2)
+#	define SSI_SRC_PERIPHERAL_PORT	(9 << 2)
+#	define SSI_DATA_TYPE_MASK	3
+#	define SSI_DATA_TYPE_S32	2
+#define SSI_GDD_CCR_REG(channel)	(0x802 + ((channel) * 0x40))
+#	define SSI_DST_AMODE_MASK	(3 << 14)
+#	define SSI_DST_AMODE_CONST	0
+#	define SSI_DST_AMODE_POSTINC	(1 << 12)
+#	define SSI_SRC_AMODE_MASK	(3 << 12)
+#	define SSI_SRC_AMODE_CONST	0
+#	define SSI_SRC_AMODE_POSTINC	(1 << 12)
+#	define SSI_CCR_ENABLE		(1 << 7)
+#	define SSI_CCR_SYNC_MASK	0x1f
+#define SSI_GDD_CICR_REG(channel)	(0x804 + ((channel) * 0x40))
+#	define SSI_BLOCK_IE		(1 << 5)
+#	define SSI_HALF_IE		(1 << 2)
+#	define SSI_TOUT_IE		(1 << 0)
+#define SSI_GDD_CSR_REG(channel)	(0x806 + ((channel) * 0x40))
+#	define SSI_CSR_SYNC		(1 << 6)
+#	define SSI_CSR_BLOCK		(1 << 5)
+#	define SSI_CSR_HALF		(1 << 2)
+#	define SSI_CSR_TOUR		(1 << 0)
+#define SSI_GDD_CSSA_REG(channel)	(0x808 + ((channel) * 0x40))
+#define SSI_GDD_CDSA_REG(channel)	(0x80c + ((channel) * 0x40))
+#define SSI_GDD_CEN_REG(channel)	(0x810 + ((channel) * 0x40))
+#define SSI_GDD_CSAC_REG(channel)	(0x818 + ((channel) * 0x40))
+#define SSI_GDD_CDAC_REG(channel)	(0x81a + ((channel) * 0x40))
+#define SSI_GDD_CLNK_CTRL_REG(channel)	(0x828 + ((channel) * 0x40))
+#	define SSI_ENABLE_LNK		(1 << 15)
+#	define SSI_STOP_LNK		(1 << 14)
+#	define SSI_NEXT_CH_ID_MASK	0xf
+
+/**
+ * struct omap_ssi_platform_data - OMAP SSI platform data
+ * @num_ports: Number of ports on the controller
+ * @ctxt_loss_count: Pointer to omap_pm_get_dev_context_loss_count
+ */
+struct omap_ssi_platform_data {
+	unsigned int	num_ports;
+	int (*get_dev_context_loss_count)(struct device *dev);
+};
+
+/**
+ * struct omap_ssi_config - SSI board configuration
+ * @num_ports: Number of ports in use
+ * @cawake_line: Array of cawake gpio lines
+ */
+struct omap_ssi_board_config {
+	unsigned int num_ports;
+	int cawake_gpio[SSI_NUM_PORTS];
+};
+
+#ifdef CONFIG_OMAP_SSI_CONFIG
+extern int omap_ssi_config(struct omap_ssi_board_config *ssi_config);
+#else
+static inline int omap_ssi_config(struct omap_ssi_board_config *ssi_config)
+{
+	return 0;
+}
+#endif /* CONFIG_OMAP_SSI_CONFIG */
+
+#endif /* __OMAP_SSI_REGS_H__ */