u8500: Vibrator: Timed output vibrator driver

ST-Ericsson vibrator driver which registers in Android specific
timed output device class.

Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
Signed-off-by: Jerzy Kasenberg <jerzy.kasenberg@tieto.com>
Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>

Timed output vibrator: New functionality.

This patch allows to form the vibration characteristic
using few parameters defined in the platform data:
- boost level and period for start condition
- on level as moderate speed
- off level and period for brake condition

Detailed information can be found here:
Documentation\DocBook\ste_timed_vibra.html

Signed-off-by: Grzegorz Sygieda <grzegorz.sygieda@tieto.com>
Signed-off-by: Krzysztof Antonowicz <krzysztof.antonowicz@tieto.com>
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>

vibrator: remove board specific control of vibrator

Platform specific control of vibrator should be
present in board file (here board-mop500.c).

So, for example if GPIO pins are used to control
the vibrator, its control function implemenation
should be in board file.

This patch provides the callback function support
in the driver for the same.

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>

android: vibrator: dont directly access ktime_t members

Use ktime helper functions for converting ktime values

Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>

u8500: vibra: linear vibrators using vibra-pwm

Linear vibrators operate on thier required resonance
frequency (for COPAL and AAC its ~150Hz). This can be
provided using AUDIO DA5 path. This software *workaround*
enables linear vibrators using AB8500 vibra-pwm by
generating required resonace frequency using software.

In addition this patch provides support for separate
platform data for Linear and Rotarty vibrators.

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>

u8500: vibra: disable vibrator after vibration

This patch disables vibrator i.e. configures
the PWM duty cycle to zero after vibration
duration is over.

Signed-off-by: Philippe Langlais <philippe.langlais@linaro.org>

u8500: optimize: linear vibra drv using vibra-pwm

This patch optimizes the current implementation
of "linear vibrator driver using vibra-pwm".
Current implementation is CPU intensive and uses
100% of a CPU for the time period vibrator is used.

ST-Ericsson ID: ER 349958

Signed-off-by: Avinash A <Avinash.a@stericsson.com>

u8500: vibra: fix sleeping fn. in atomic context

sleepable call - flush_workqueue called from atomic
context of vibra_enable.

ST-Ericsson ID: ER 351276

Signed-off-by: Avinash A <Avinash.a@stericsson.com>

u8500: vibra: remove race condition in timer operation

In situation described below, vibra driver can hang.

In a scenario where vibra_enable is called and vibrator
is running i.e. vibra_work is scheduled and vibra_timer.
Suppose vibra_timer is started and has not expired yet.
At this moment if vibra_work starts executing and acquires
the vibra_lock and just before hrtimer_cancel is called,
if old timer expires and timer callback starts executing
then it will try to acquire vibra_lock and hence it will
wait for vibra_lock, as it is already acquired by vibra_work.

Now vibra_work->hrtimer_cancel will wait for timer callback
to complete and timer callback will wait for vibra_lock to
be free so that it can complete. This result in recursive
waiting for vibra_lock and hence deadlock.

As timer callback is running in interrupt context so above
deadlock may trigger watchdog.

ST-Ericsson ID: 405366

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>

u8500: vibra: remove race condition in open

In situation described below, vibra driver can hang.
vibra_enable takes the vibra_lock and timer expires then
timer callback will spin for vibra_lock. If vibra_enable
tries to do hrtimer_cancel then it will wait for timer
callback to complete.

In above situation hrtimer_cancel will wait for timer callback
to complete and timer callback will wait for vibra_lock to
be free so that it can complete. This result in recursive
waiting for vibra_lock and hence deadlock.

As timer callback is running in interrupt context so above
deadlock may trigger watchdog.

ST-Ericsson ID: 407253

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>

vibra:Remove unnecessary assignment of dev->parent

Remove unnecessary assignment of dev->parent,
because of this during timed out class unregister
it is trying to free resources of parent which
does not exist

Signed-off-by: Naga Radhesh <naga.radheshy@stericsson.com>

3 files changed, 440 insertions, 0 deletions

diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index eb1dee26bda..7823c2a19ed 100644
--- a/drivers/staging/android/Kconfig
+++ b/drivers/staging/android/Kconfig
@@ -53,6 +53,14 @@ config ANDROID_LOW_MEMORY_KILLER
 	---help---
 	  Register processes to be killed when memory is low
 
+config ANDROID_STE_TIMED_VIBRA
+	bool "ST-Ericsson Timed Output Vibrator"
+	depends on SND_SOC_AB8500
+	depends on ANDROID_TIMED_OUTPUT
+	default y
+	help
+	  ST-Ericsson's vibrator driver using timed output class device
+
 source "drivers/staging/android/switch/Kconfig"
 
 config ANDROID_INTF_ALARM
diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile
index 9b6c9ed91f6..e529c63da57 100644
--- a/drivers/staging/android/Makefile
+++ b/drivers/staging/android/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_ANDROID_RAM_CONSOLE)	+= ram_console.o
 obj-$(CONFIG_ANDROID_TIMED_OUTPUT)	+= timed_output.o
 obj-$(CONFIG_ANDROID_TIMED_GPIO)	+= timed_gpio.o
 obj-$(CONFIG_ANDROID_LOW_MEMORY_KILLER)	+= lowmemorykiller.o
+obj-$(CONFIG_ANDROID_STE_TIMED_VIBRA)	+= ste_timed_vibra.o
 obj-$(CONFIG_ANDROID_SWITCH)		+= switch/
 obj-$(CONFIG_ANDROID_INTF_ALARM)	+= alarm.o
 obj-$(CONFIG_ANDROID_INTF_ALARM_DEV)	+= alarm-dev.o
diff --git a/drivers/staging/android/ste_timed_vibra.c b/drivers/staging/android/ste_timed_vibra.c
new file mode 100644
index 00000000000..4621b2fb441
--- /dev/null
+++ b/drivers/staging/android/ste_timed_vibra.c
@@ -0,0 +1,431 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ * Author: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
+ *	   for ST-Ericsson
+ * License Terms: GNU General Public License v2
+ */
+
+#include <linux/kernel.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/ste_timed_vibra.h>
+#include <linux/delay.h>
+#include "timed_output.h"
+
+/**
+ * struct vibra_info - Vibrator information structure
+ * @tdev:		Pointer to timed output device structure
+ * @linear_workqueue:   Pointer to linear vibrator workqueue structure
+ * @linear_work:	Linear Vibrator work
+ * @linear_tick:	Linear Vibrator high resolution timer
+ * @vibra_workqueue:    Pointer to vibrator workqueue structure
+ * @vibra_work:		Vibrator work
+ * @vibra_timer:	Vibrator high resolution timer
+ * @vibra_lock:		Vibrator lock
+ * @vibra_state:	Actual vibrator state
+ * @state_force:	Indicates if oppositive state is requested
+ * @timeout:		Indicates how long time the vibrator will be enabled
+ * @time_passed:	Total time passed in states
+ * @pdata:		Local pointer to platform data with vibrator parameters
+ *
+ * Structure vibra_info holds vibrator information
+ **/
+struct vibra_info {
+	struct timed_output_dev			tdev;
+	struct workqueue_struct			*linear_workqueue;
+	struct work_struct			linear_work;
+	struct hrtimer				linear_tick;
+	struct workqueue_struct			*vibra_workqueue;
+	struct work_struct			vibra_work;
+	struct hrtimer				vibra_timer;
+	spinlock_t				vibra_lock;
+	enum ste_timed_vibra_states		vibra_state;
+	bool					state_force;
+	unsigned int				timeout;
+	unsigned int				time_passed;
+	struct ste_timed_vibra_platform_data	*pdata;
+};
+
+/*
+ * Linear vibrator hardware operates on a particular resonance
+ * frequency. The resonance frequency (f) may also vary with h/w.
+ * This define is half time period (t) in micro seconds (us).
+ * For resonance frequency f = 150 Hz
+ * t = T/2 = ((1/150) / 2) = 3333 usec.
+ */
+#define LINEAR_RESONANCE	3333
+
+/**
+ * linear_vibra_work() - Linear Vibrator work, turns on/off vibrator
+ * @work:	Pointer to work structure
+ *
+ * This function is called from workqueue, turns on/off vibrator
+ **/
+static void linear_vibra_work(struct work_struct *work)
+{
+	struct vibra_info *vinfo =
+			container_of(work, struct vibra_info, linear_work);
+	unsigned char speed_pos = 0, speed_neg = 0;
+	ktime_t ktime;
+	static unsigned char toggle;
+
+	if (toggle) {
+		speed_pos = vinfo->pdata->boost_level;
+		speed_neg = 0;
+	} else {
+		speed_neg = vinfo->pdata->boost_level;
+		speed_pos = 0;
+	}
+
+	toggle = !toggle;
+	vinfo->pdata->timed_vibra_control(speed_pos, speed_neg,
+			speed_pos, speed_neg);
+
+	if ((vinfo->vibra_state != STE_VIBRA_IDLE) &&
+		(vinfo->vibra_state != STE_VIBRA_OFF)) {
+		ktime = ktime_set((LINEAR_RESONANCE / USEC_PER_SEC),
+			(LINEAR_RESONANCE % USEC_PER_SEC) * NSEC_PER_USEC);
+		hrtimer_start(&vinfo->linear_tick, ktime, HRTIMER_MODE_REL);
+	}
+}
+
+/**
+ * vibra_control_work() - Vibrator work, turns on/off vibrator
+ * @work:	Pointer to work structure
+ *
+ * This function is called from workqueue, turns on/off vibrator
+ **/
+static void vibra_control_work(struct work_struct *work)
+{
+	struct vibra_info *vinfo =
+			container_of(work, struct vibra_info, vibra_work);
+	unsigned val = 0;
+	unsigned char speed_pos = 0, speed_neg = 0;
+	unsigned long flags;
+
+	/*
+	 * Cancel scheduled timer if it has not started
+	 * else it will wait for timer callback to complete.
+	 * It should be done before taking vibra_lock to
+	 * prevent race condition, as timer callback also
+	 * takes same lock.
+	 */
+	hrtimer_cancel(&vinfo->vibra_timer);
+
+	spin_lock_irqsave(&vinfo->vibra_lock, flags);
+
+	switch (vinfo->vibra_state) {
+	case STE_VIBRA_BOOST:
+		/* Turn on both vibrators with boost speed */
+		speed_pos = vinfo->pdata->boost_level;
+		val = vinfo->pdata->boost_time;
+		break;
+	case STE_VIBRA_ON:
+		/* Turn on both vibrators with speed */
+		speed_pos = vinfo->pdata->on_level;
+		val = vinfo->timeout - vinfo->pdata->boost_time;
+		break;
+	case STE_VIBRA_OFF:
+		/* Turn on both vibrators with reversed speed */
+		speed_neg = vinfo->pdata->off_level;
+		val = vinfo->pdata->off_time;
+		break;
+	case STE_VIBRA_IDLE:
+		vinfo->time_passed = 0;
+		break;
+	default:
+		break;
+	}
+	spin_unlock_irqrestore(&vinfo->vibra_lock, flags);
+
+	/* Send new settings (only for rotary vibrators) */
+	if (!vinfo->pdata->is_linear_vibra)
+		vinfo->pdata->timed_vibra_control(speed_pos, speed_neg,
+				speed_pos, speed_neg);
+
+	if (vinfo->vibra_state != STE_VIBRA_IDLE) {
+		/* Start timer if it's not in IDLE state */
+		ktime_t ktime;
+		ktime = ktime_set((val / MSEC_PER_SEC),
+				(val % MSEC_PER_SEC) * NSEC_PER_MSEC),
+		hrtimer_start(&vinfo->vibra_timer, ktime, HRTIMER_MODE_REL);
+	} else if (vinfo->pdata->is_linear_vibra) {
+		/* Cancel work and timers of linear vibrator in IDLE state */
+		hrtimer_cancel(&vinfo->linear_tick);
+		flush_workqueue(vinfo->linear_workqueue);
+		vinfo->pdata->timed_vibra_control(0, 0, 0, 0);
+	}
+}
+
+/**
+ * vibra_enable() - Enables vibrator
+ * @tdev:      Pointer to timed output device structure
+ * @timeout:	Time indicating how long vibrator will be enabled
+ *
+ * This function enables vibrator
+ **/
+static void vibra_enable(struct timed_output_dev *tdev, int timeout)
+{
+	struct vibra_info *vinfo = dev_get_drvdata(tdev->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vinfo->vibra_lock, flags);
+	switch (vinfo->vibra_state) {
+	case STE_VIBRA_IDLE:
+		if (timeout)
+			vinfo->vibra_state = STE_VIBRA_BOOST;
+		else    /* Already disabled */
+			break;
+
+		vinfo->state_force = false;
+		/* Trim timeout */
+		vinfo->timeout = timeout < vinfo->pdata->boost_time ?
+				vinfo->pdata->boost_time : timeout;
+
+		if (vinfo->pdata->is_linear_vibra)
+			queue_work(vinfo->linear_workqueue,
+					&vinfo->linear_work);
+		queue_work(vinfo->vibra_workqueue, &vinfo->vibra_work);
+		break;
+	case STE_VIBRA_BOOST:
+		/* Force only when user requested OFF while BOOST */
+		if (!timeout)
+			vinfo->state_force = true;
+		break;
+	case STE_VIBRA_ON:
+		/* If user requested OFF */
+		if (!timeout) {
+			if (vinfo->pdata->is_linear_vibra)
+				hrtimer_cancel(&vinfo->linear_tick);
+			/* Cancel timer if it has not expired yet.
+			 * Else setting the vibra_state to STE_VIBRA_OFF
+			 * will make take care that vibrator will move to
+			 * STE_VIBRA_IDLE in timer callback just after
+			 * this function call.
+			 */
+			hrtimer_try_to_cancel(&vinfo->vibra_timer);
+			vinfo->vibra_state = STE_VIBRA_OFF;
+			queue_work(vinfo->vibra_workqueue, &vinfo->vibra_work);
+		}
+		break;
+	case STE_VIBRA_OFF:
+		/* Force only when user requested ON while OFF */
+		if (timeout)
+			vinfo->state_force = true;
+		break;
+	default:
+		break;
+	}
+	spin_unlock_irqrestore(&vinfo->vibra_lock, flags);
+}
+
+/**
+ * linear_vibra_tick() - Generate resonance frequency waveform
+ * @hrtimer: Pointer to high resolution timer structure
+ *
+ * This function helps in generating the resonance frequency
+ * waveform required for linear vibrators
+ *
+ * Returns:
+ *	Returns value which indicates whether hrtimer should be restarted
+ **/
+static enum hrtimer_restart linear_vibra_tick(struct hrtimer *hrtimer)
+{
+	struct vibra_info *vinfo =
+			container_of(hrtimer, struct vibra_info, linear_tick);
+
+	if ((vinfo->vibra_state != STE_VIBRA_IDLE) &&
+		(vinfo->vibra_state != STE_VIBRA_OFF)) {
+		queue_work(vinfo->linear_workqueue, &vinfo->linear_work);
+	}
+
+	return HRTIMER_NORESTART;
+}
+
+/**
+ * vibra_timer_expired() - Handles vibrator machine state
+ * @hrtimer:      Pointer to high resolution timer structure
+ *
+ * This function handles vibrator machine state
+ *
+ * Returns:
+ *	Returns value which indicates wether hrtimer should be restarted
+ **/
+static enum hrtimer_restart vibra_timer_expired(struct hrtimer *hrtimer)
+{
+	struct vibra_info *vinfo =
+			container_of(hrtimer, struct vibra_info, vibra_timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vinfo->vibra_lock, flags);
+	switch (vinfo->vibra_state) {
+	case STE_VIBRA_BOOST:
+		/* If BOOST finished and force, go to OFF */
+		if (vinfo->state_force)
+			vinfo->vibra_state = STE_VIBRA_OFF;
+		else
+			vinfo->vibra_state = STE_VIBRA_ON;
+		vinfo->time_passed = vinfo->pdata->boost_time;
+		break;
+	case STE_VIBRA_ON:
+		vinfo->vibra_state = STE_VIBRA_OFF;
+		vinfo->time_passed = vinfo->timeout;
+		break;
+	case STE_VIBRA_OFF:
+		/* If OFF finished and force, go to ON */
+		if (vinfo->state_force)
+			vinfo->vibra_state = STE_VIBRA_ON;
+		else
+			vinfo->vibra_state = STE_VIBRA_IDLE;
+		vinfo->time_passed += vinfo->pdata->off_time;
+		break;
+	case STE_VIBRA_IDLE:
+		break;
+	default:
+		break;
+	}
+	vinfo->state_force = false;
+	spin_unlock_irqrestore(&vinfo->vibra_lock, flags);
+
+	queue_work(vinfo->vibra_workqueue, &vinfo->vibra_work);
+
+	return HRTIMER_NORESTART;
+}
+
+/**
+ * vibra_get_time() - Returns remaining time to disabling vibration
+ * @tdev:      Pointer to timed output device structure
+ *
+ * This function returns time remaining to disabling vibration
+ *
+ * Returns:
+ *	Returns remaining time to disabling vibration
+ **/
+static int vibra_get_time(struct timed_output_dev *tdev)
+{
+	struct vibra_info *vinfo = dev_get_drvdata(tdev->dev);
+	u32 ms;
+
+	if (hrtimer_active(&vinfo->vibra_timer)) {
+		ktime_t remain = hrtimer_get_remaining(&vinfo->vibra_timer);
+		ms = (u32) ktime_to_ms(remain);
+		return ms + vinfo->time_passed;
+	} else
+		return 0;
+}
+
+static int __devinit ste_timed_vibra_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct vibra_info *vinfo;
+
+	if (!pdev->dev.platform_data) {
+		dev_err(&pdev->dev, "No platform data supplied\n");
+		return -ENODEV;
+	}
+
+	vinfo = kmalloc(sizeof *vinfo, GFP_KERNEL);
+	if (!vinfo) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
+	vinfo->tdev.name = "vibrator";
+	vinfo->tdev.enable = vibra_enable;
+	vinfo->tdev.get_time = vibra_get_time;
+	vinfo->time_passed = 0;
+	vinfo->vibra_state = STE_VIBRA_IDLE;
+	vinfo->state_force = false;
+	vinfo->pdata = pdev->dev.platform_data;
+
+	if (vinfo->pdata->is_linear_vibra)
+		dev_info(&pdev->dev, "Linear Type Vibrators\n");
+	else
+		dev_info(&pdev->dev, "Rotary Type Vibrators\n");
+
+	ret = timed_output_dev_register(&vinfo->tdev);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register timed output device\n");
+		goto exit_free_vinfo;
+	}
+
+	dev_set_drvdata(vinfo->tdev.dev, vinfo);
+
+	vinfo->linear_workqueue =
+		create_singlethread_workqueue("ste-timed-linear-vibra");
+	if (!vinfo->linear_workqueue) {
+		dev_err(&pdev->dev, "failed to allocate workqueue\n");
+		ret = -ENOMEM;
+		goto exit_timed_output_unregister;
+	}
+
+	/* Create workqueue just for timed output vibrator */
+	vinfo->vibra_workqueue =
+		create_singlethread_workqueue("ste-timed-output-vibra");
+	if (!vinfo->vibra_workqueue) {
+		dev_err(&pdev->dev, "failed to allocate workqueue\n");
+		ret = -ENOMEM;
+		goto exit_destroy_workqueue;
+	}
+
+	INIT_WORK(&vinfo->linear_work, linear_vibra_work);
+	INIT_WORK(&vinfo->vibra_work, vibra_control_work);
+	spin_lock_init(&vinfo->vibra_lock);
+	hrtimer_init(&vinfo->linear_tick, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_init(&vinfo->vibra_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	vinfo->linear_tick.function = linear_vibra_tick;
+	vinfo->vibra_timer.function = vibra_timer_expired;
+
+	platform_set_drvdata(pdev, vinfo);
+	return 0;
+
+exit_destroy_workqueue:
+	destroy_workqueue(vinfo->linear_workqueue);
+exit_timed_output_unregister:
+	timed_output_dev_unregister(&vinfo->tdev);
+exit_free_vinfo:
+	kfree(vinfo);
+	return ret;
+}
+
+static int __devexit ste_timed_vibra_remove(struct platform_device *pdev)
+{
+	struct vibra_info *vinfo = platform_get_drvdata(pdev);
+
+	timed_output_dev_unregister(&vinfo->tdev);
+	destroy_workqueue(vinfo->linear_workqueue);
+	destroy_workqueue(vinfo->vibra_workqueue);
+	kfree(vinfo);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver ste_timed_vibra_driver = {
+	.driver = {
+		.name = "ste_timed_output_vibra",
+		.owner = THIS_MODULE,
+	},
+	.probe  = ste_timed_vibra_probe,
+	.remove = __devexit_p(ste_timed_vibra_remove)
+};
+
+static int __init ste_timed_vibra_init(void)
+{
+	return platform_driver_register(&ste_timed_vibra_driver);
+}
+module_init(ste_timed_vibra_init);
+
+static void __exit ste_timed_vibra_exit(void)
+{
+	platform_driver_unregister(&ste_timed_vibra_driver);
+}
+module_exit(ste_timed_vibra_exit);
+
+MODULE_AUTHOR("Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>");
+MODULE_DESCRIPTION("STE Timed Output Vibrator");
+MODULE_LICENSE("GPL v2");