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Commit 312b00e1 authored by Ashish Jangam's avatar Ashish Jangam Committed by Wim Van Sebroeck
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watchdog: DA9055 Watchdog driver 



This is the Watchdog patch for the DA9055 PMIC. This patch has got dependency on
the DA9055 MFD core.

This patch is functionally tested on SMDK6410

Signed-off-by: default avatarDavid Dajun Chen <dchen@diasemi.com>
Signed-off-by: default avatarAshish Jangam <ashish.jangam@kpitcummins.com>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent 1ba85387

drivers/watchdog/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -76,6 +76,16 @@ config DA9052_WATCHDOG 
          Alternatively say M to compile the driver as a module,

          which will be called da9052_wdt.



config DA9055_WATCHDOG

	tristate "Dialog Semiconductor DA9055 Watchdog"

	depends on MFD_DA9055

	help

	  If you say yes here you get support for watchdog on the Dialog

	  Semiconductor DA9055 PMIC.



	  This driver can also be built as a module.  If so, the module

	  will be called da9055_wdt.



config WM831X_WATCHDOG

	tristate "WM831x watchdog"

	depends on MFD_WM831X

drivers/watchdog/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -164,6 +164,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o 


# Architecture Independent

obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o

obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o

obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o

obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o

obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o

drivers/watchdog/da9055_wdt.c

0 → 100644
+216 −0
Original line number Diff line number Diff line 
/*

 * System monitoring driver for DA9055 PMICs.

 *

 * Copyright(c) 2012 Dialog Semiconductor Ltd.

 *

 * Author: David Dajun Chen <dchen@diasemi.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 */



#include <linux/module.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/slab.h>

#include <linux/platform_device.h>

#include <linux/watchdog.h>

#include <linux/delay.h>



#include <linux/mfd/da9055/core.h>

#include <linux/mfd/da9055/reg.h>



static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout,

		 "Watchdog cannot be stopped once started (default="

		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");



#define DA9055_DEF_TIMEOUT	4

#define DA9055_TWDMIN		256



struct da9055_wdt_data {

	struct watchdog_device wdt;

	struct da9055 *da9055;

	struct kref kref;

};



static const struct {

	u8 reg_val;

	int user_time;  /* In seconds */

} da9055_wdt_maps[] = {

	{ 0, 0 },

	{ 1, 2 },

	{ 2, 4 },

	{ 3, 8 },

	{ 4, 16 },

	{ 5, 32 },

	{ 5, 33 },  /* Actual time  32.768s so included both 32s and 33s */

	{ 6, 65 },

	{ 6, 66 },  /* Actual time 65.536s so include both, 65s and 66s */

	{ 7, 131 },

};



static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev,

				  unsigned int timeout)

{

	struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);

	struct da9055 *da9055 = driver_data->da9055;

	int ret, i;



	for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++)

		if (da9055_wdt_maps[i].user_time == timeout)

			break;



	if (i == ARRAY_SIZE(da9055_wdt_maps))

		ret = -EINVAL;

	else

		ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,

					DA9055_TWDSCALE_MASK,

					da9055_wdt_maps[i].reg_val <<

					DA9055_TWDSCALE_SHIFT);

	if (ret < 0)

		dev_err(da9055->dev,

			"Failed to update timescale bit, %d\n", ret);



	wdt_dev->timeout = timeout;



	return ret;

}



static int da9055_wdt_ping(struct watchdog_device *wdt_dev)

{

	struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);

	struct da9055 *da9055 = driver_data->da9055;

	int ret;



	/*

	 * We have a minimum time for watchdog window called TWDMIN. A write

	 * to the watchdog before this elapsed time will cause an error.

	 */

	mdelay(DA9055_TWDMIN);



	/* Reset the watchdog timer */

	ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_E,

				DA9055_WATCHDOG_MASK, 1);



	return ret;

}



static void da9055_wdt_release_resources(struct kref *r)

{

	struct da9055_wdt_data *driver_data =

		container_of(r, struct da9055_wdt_data, kref);



	kfree(driver_data);

}



static void da9055_wdt_ref(struct watchdog_device *wdt_dev)

{

	struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);



	kref_get(&driver_data->kref);

}



static void da9055_wdt_unref(struct watchdog_device *wdt_dev)

{

	struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);



	kref_put(&driver_data->kref, da9055_wdt_release_resources);

}



static int da9055_wdt_start(struct watchdog_device *wdt_dev)

{

	return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout);

}



static int da9055_wdt_stop(struct watchdog_device *wdt_dev)

{

	return da9055_wdt_set_timeout(wdt_dev, 0);

}



static struct watchdog_info da9055_wdt_info = {

	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,

	.identity	= "DA9055 Watchdog",

};



static const struct watchdog_ops da9055_wdt_ops = {

	.owner = THIS_MODULE,

	.start = da9055_wdt_start,

	.stop = da9055_wdt_stop,

	.ping = da9055_wdt_ping,

	.set_timeout = da9055_wdt_set_timeout,

	.ref = da9055_wdt_ref,

	.unref = da9055_wdt_unref,

};



static int da9055_wdt_probe(struct platform_device *pdev)

{

	struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);

	struct da9055_wdt_data *driver_data;

	struct watchdog_device *da9055_wdt;

	int ret;



	driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),

				   GFP_KERNEL);

	if (!driver_data) {

		dev_err(da9055->dev, "Failed to allocate watchdog device\n");

		return -ENOMEM;

	}



	driver_data->da9055 = da9055;



	da9055_wdt = &driver_data->wdt;



	da9055_wdt->timeout = DA9055_DEF_TIMEOUT;

	da9055_wdt->info = &da9055_wdt_info;

	da9055_wdt->ops = &da9055_wdt_ops;

	watchdog_set_nowayout(da9055_wdt, nowayout);

	watchdog_set_drvdata(da9055_wdt, driver_data);



	kref_init(&driver_data->kref);



	ret = da9055_wdt_stop(da9055_wdt);

	if (ret < 0) {

		dev_err(&pdev->dev, "Failed to stop watchdog, %d\n", ret);

		goto err;

	}



	dev_set_drvdata(&pdev->dev, driver_data);



	ret = watchdog_register_device(&driver_data->wdt);

	if (ret != 0)

		dev_err(da9055->dev, "watchdog_register_device() failed: %d\n",

			ret);



err:

	return ret;

}



static int da9055_wdt_remove(struct platform_device *pdev)

{

	struct da9055_wdt_data *driver_data = dev_get_drvdata(&pdev->dev);



	watchdog_unregister_device(&driver_data->wdt);

	kref_put(&driver_data->kref, da9055_wdt_release_resources);



	return 0;

}



static struct platform_driver da9055_wdt_driver = {

	.probe = da9055_wdt_probe,

	.remove = da9055_wdt_remove,

	.driver = {

		.name	= "da9055-watchdog",

	},

};



module_platform_driver(da9055_wdt_driver);



MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");

MODULE_DESCRIPTION("DA9055 watchdog");

MODULE_LICENSE("GPL");

MODULE_ALIAS("platform:da9055-watchdog");