drivers/watchdog/palmas_wdt.c - kernel/tegra - Git at Google

 /*
  * palmas_wdt.c -- Palmas Watchdog Timer.
  *
  * Watchdog timer for Palmas PMIC.
  *
  * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
  *
  * Author: Laxman Dewangan <ldewangan@nvidia.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 version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  * whether express or implied; 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., 59 Temple Place, Suite 330, Boston, MA
  * 02111-1307, USA
  */

 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/mfd/palmas.h>
 #include <linux/platform_device.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/watchdog.h>

 static bool nowayout = WATCHDOG_NOWAYOUT;

 struct palmas_wdt {
 	struct watchdog_device wdt_dev;
 	struct device *dev;
 	struct palmas *palmas;
 	int timeout;
 	int irq;
 	int locked;
 };

 static irqreturn_t palmas_wdt_irq(int irq, void *data)
 {
 	struct palmas_wdt *wdt = data;

 	dev_info(wdt->dev, "WDT interrupt occur\n");
 	return IRQ_HANDLED;
 }

 static int palmas_wdt_start(struct watchdog_device *wdt_dev)
 {
 	struct palmas_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	int ret;

 	if (wdt->locked) {
 		dev_err(wdt->dev,
 			"Watchdog timer is locked, can not control\n");
 		return -EBUSY;
 	}

 	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
 			PALMAS_WATCHDOG, PALMAS_WATCHDOG_ENABLE,
 			PALMAS_WATCHDOG_ENABLE);
 	if (ret < 0) {
 		dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
 		return ret;
 	}

 	dev_info(wdt->dev, "WDT Started\n");
 	return 0;
 }

 static int palmas_wdt_stop(struct watchdog_device *wdt_dev)
 {
 	struct palmas_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	int ret;

 	if (wdt->locked) {
 		dev_err(wdt->dev,
 			"Watchdog timer is locked, can not control\n");
 		return -EBUSY;
 	}

 	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
 			PALMAS_WATCHDOG, PALMAS_WATCHDOG_ENABLE, 0);
 	if (ret < 0) {
 		dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
 		return ret;
 	}
 	dev_info(wdt->dev, "WDT Stopped\n");
 	return 0;
 }

 static int palmas_wdt_set_timeout(struct watchdog_device *wdt_dev,
 		unsigned int timeout)
 {
 	struct palmas_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	int i;
 	int ret;
 	unsigned int bit = 1;

 	for (i = 0; i < 7; ++i) {
 		if (timeout <= bit)
 			break;

 		bit <<= 1;
 	}

 	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
 			PALMAS_WATCHDOG, PALMAS_WATCHDOG_TIMER_MASK, i);
 	if (ret < 0) {
 		dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
 		return ret;
 	}
 	wdt->timeout = timeout;
 	dev_info(wdt->dev, "WDT Timeout %d\n", timeout);
 	return 0;
 }

 static const struct watchdog_info palmas_wdt_info = {
 	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 	.identity = "Palmas Watchdog",
 };

 static const struct watchdog_ops palmas_wdt_ops = {
 	.owner = THIS_MODULE,
 	.start = palmas_wdt_start,
 	.stop = palmas_wdt_stop,
 	.set_timeout = palmas_wdt_set_timeout,
 };

 static int palmas_wdt_probe(struct platform_device *pdev)
 {
 	struct palmas_platform_data *pdata;
 	struct palmas_wdt *wdt;
 	struct watchdog_device *wdt_dev;
 	unsigned int regval;
 	u32 pval;
 	int wdt_timer_period = 0;
 	int ret;

 	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
 	if (!wdt)
 		return -ENOMEM;

 	pdata = dev_get_platdata(pdev->dev.parent);
 	if (pdata)
 		wdt_timer_period = pdata->watchdog_timer_initial_period;
 	if (!wdt_timer_period && pdev->dev.of_node) {
 		ret = of_property_read_u32(pdev->dev.of_node,
 				"ti,system-watchdog-timer-period", &pval);
 		if (!ret)
 			wdt_timer_period = pval;
 	}

 	wdt->dev = &pdev->dev;
 	wdt->palmas = dev_get_drvdata(pdev->dev.parent);
 	wdt->irq = palmas_irq_get_virq(wdt->palmas, PALMAS_WDT_IRQ);
 	wdt_dev = &wdt->wdt_dev;

 	wdt_dev->info = &palmas_wdt_info;
 	wdt_dev->ops = &palmas_wdt_ops;
 	wdt_dev->timeout = 128;
 	wdt_dev->min_timeout = 1;
 	wdt_dev->max_timeout = 128;
 	watchdog_set_nowayout(wdt_dev, nowayout);
 	watchdog_set_drvdata(wdt_dev, wdt);
 	platform_set_drvdata(pdev, wdt);

 	ret = request_threaded_irq(wdt->irq, NULL, palmas_wdt_irq,
 			IRQF_ONESHOT | IRQF_EARLY_RESUME,
 			dev_name(&pdev->dev), wdt);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
 			 wdt->irq, ret);
 		return ret;
 	}

 	ret = watchdog_register_device(wdt_dev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
 		return ret;
 	}

 	ret = palmas_read(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
 			PALMAS_WATCHDOG, &regval);
 	if (ret < 0) {
 		dev_err(wdt->dev, "WATCHDOG read failed: %d\n", ret);
 		goto scrub;
 	}

 	if (regval & PALMAS_WATCHDOG_LOCK) {
 		dev_info(wdt->dev, "watchdog timer Locked\n");
 		wdt->locked = true;
 	} else {
 		dev_info(wdt->dev, "watchdog timer unlocked\n");
 		wdt->locked = false;
 	}

 	if (!wdt->locked) {
 		ret = palmas_wdt_stop(wdt_dev);
 		if (ret < 0) {
 			dev_err(wdt->dev, "wdt stop failed: %d\n", ret);
 			goto scrub;
 		}
 	}

 	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
 			PALMAS_WATCHDOG, PALMAS_WATCHDOG_MODE, 0);
 	if (ret < 0) {
 		dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
 		goto scrub;
 	}

 	if (wdt_timer_period) {
 		ret = palmas_wdt_set_timeout(wdt_dev, wdt_timer_period);
 		if (ret < 0) {
 			dev_err(wdt->dev, "wdt set timeout failed: %d\n", ret);
 			goto scrub;
 		}
 		if (!wdt->locked) {
 			ret = palmas_wdt_start(wdt_dev);
 			if (ret < 0) {
 				dev_err(wdt->dev,
 					"wdt start failed: %d\n", ret);
 				goto scrub;
 			}
 		}
 	}

 	device_set_wakeup_capable(&pdev->dev, 1);
 	return 0;
 scrub:
 	free_irq(wdt->irq, wdt);
 	watchdog_unregister_device(&wdt->wdt_dev);
 	return ret;
 }

 static int palmas_wdt_remove(struct platform_device *pdev)
 {
 	struct palmas_wdt *wdt = platform_get_drvdata(pdev);

 	palmas_wdt_stop(&wdt->wdt_dev);
 	watchdog_unregister_device(&wdt->wdt_dev);
 	free_irq(wdt->irq, wdt);
 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int palmas_wdt_suspend(struct device *dev)
 {
 	struct palmas_wdt *wdt = dev_get_drvdata(dev);
 	int ret;

 	if (device_may_wakeup(dev)) {
 		enable_irq_wake(wdt->irq);
 	} else if (wdt->timeout > 0) {
 		ret = palmas_wdt_stop(&wdt->wdt_dev);
 		if (ret < 0)
 			dev_err(wdt->dev, "wdt stop failed: %d\n", ret);
 	}
 	return 0;
 }

 static int palmas_wdt_resume(struct device *dev)
 {
 	struct palmas_wdt *wdt = dev_get_drvdata(dev);
 	int ret;

 	if (device_may_wakeup(dev)) {
 		disable_irq_wake(wdt->irq);
 	} else if (wdt->timeout > 0) {
 		ret = palmas_wdt_start(&wdt->wdt_dev);
 		if (ret < 0)
 			dev_err(wdt->dev, "wdt start failed: %d\n", ret);
 	}
 	return 0;
 }
 #endif

 static const struct dev_pm_ops palmas_wdt_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(palmas_wdt_suspend, palmas_wdt_resume)
 };

 static struct of_device_id of_palmas_wdt_match_tbl[] = {
 	{ .compatible = "ti,palmas-watchdog", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, of_palmas_wdt_match_tbl);

 static struct platform_driver palmas_wdt_driver = {
 	.driver	= {
 		.name	= "palmas-wdt",
 		.owner	= THIS_MODULE,
 		.pm = &palmas_wdt_pm_ops,
 		.of_match_table = of_palmas_wdt_match_tbl,
 	},
 	.probe	= palmas_wdt_probe,
 	.remove	= palmas_wdt_remove,
 };

 static int __init palmas_wdt_init(void)
 {
 	return platform_driver_register(&palmas_wdt_driver);
 }
 subsys_initcall(palmas_wdt_init);

 static void __exit palmas_wdt_exit(void)
 {
 	platform_driver_unregister(&palmas_wdt_driver);
 }
 module_exit(palmas_wdt_exit);

 MODULE_ALIAS("platform:palmas-wdt");
 MODULE_DESCRIPTION("TI Palmas watchdog timer driver");
 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* palmas_wdt.c -- Palmas Watchdog Timer.
	*
	* Watchdog timer for Palmas PMIC.
	*
	* Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
	*
	* Author: Laxman Dewangan <ldewangan@nvidia.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 version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
	* whether express or implied; 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., 59 Temple Place, Suite 330, Boston, MA
	* 02111-1307, USA
	*/

	#include <linux/device.h>
	#include <linux/err.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/mfd/palmas.h>
	#include <linux/platform_device.h>
	#include <linux/pm.h>
	#include <linux/slab.h>
	#include <linux/watchdog.h>

	static bool nowayout = WATCHDOG_NOWAYOUT;

	struct palmas_wdt {
	struct watchdog_device wdt_dev;
	struct device *dev;
	struct palmas *palmas;
	int timeout;
	int irq;
	int locked;
	};

	static irqreturn_t palmas_wdt_irq(int irq, void *data)
	{
	struct palmas_wdt *wdt = data;

	dev_info(wdt->dev, "WDT interrupt occur\n");
	return IRQ_HANDLED;
	}

	static int palmas_wdt_start(struct watchdog_device *wdt_dev)
	{
	struct palmas_wdt *wdt = watchdog_get_drvdata(wdt_dev);
	int ret;

	if (wdt->locked) {
	dev_err(wdt->dev,
	"Watchdog timer is locked, can not control\n");
	return -EBUSY;
	}

	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
	PALMAS_WATCHDOG, PALMAS_WATCHDOG_ENABLE,
	PALMAS_WATCHDOG_ENABLE);
	if (ret < 0) {
	dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
	return ret;
	}

	dev_info(wdt->dev, "WDT Started\n");
	return 0;
	}

	static int palmas_wdt_stop(struct watchdog_device *wdt_dev)
	{
	struct palmas_wdt *wdt = watchdog_get_drvdata(wdt_dev);
	int ret;

	if (wdt->locked) {
	dev_err(wdt->dev,
	"Watchdog timer is locked, can not control\n");
	return -EBUSY;
	}

	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
	PALMAS_WATCHDOG, PALMAS_WATCHDOG_ENABLE, 0);
	if (ret < 0) {
	dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
	return ret;
	}
	dev_info(wdt->dev, "WDT Stopped\n");
	return 0;
	}

	static int palmas_wdt_set_timeout(struct watchdog_device *wdt_dev,
	unsigned int timeout)
	{
	struct palmas_wdt *wdt = watchdog_get_drvdata(wdt_dev);
	int i;
	int ret;
	unsigned int bit = 1;

	for (i = 0; i < 7; ++i) {
	if (timeout <= bit)
	break;

	bit <<= 1;
	}

	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
	PALMAS_WATCHDOG, PALMAS_WATCHDOG_TIMER_MASK, i);
	if (ret < 0) {
	dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
	return ret;
	}
	wdt->timeout = timeout;
	dev_info(wdt->dev, "WDT Timeout %d\n", timeout);
	return 0;
	}

	static const struct watchdog_info palmas_wdt_info = {
	.options = WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
	.identity = "Palmas Watchdog",
	};

	static const struct watchdog_ops palmas_wdt_ops = {
	.owner = THIS_MODULE,
	.start = palmas_wdt_start,
	.stop = palmas_wdt_stop,
	.set_timeout = palmas_wdt_set_timeout,
	};

	static int palmas_wdt_probe(struct platform_device *pdev)
	{
	struct palmas_platform_data *pdata;
	struct palmas_wdt *wdt;
	struct watchdog_device *wdt_dev;
	unsigned int regval;
	u32 pval;
	int wdt_timer_period = 0;
	int ret;

	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	if (!wdt)
	return -ENOMEM;

	pdata = dev_get_platdata(pdev->dev.parent);
	if (pdata)
	wdt_timer_period = pdata->watchdog_timer_initial_period;
	if (!wdt_timer_period && pdev->dev.of_node) {
	ret = of_property_read_u32(pdev->dev.of_node,
	"ti,system-watchdog-timer-period", &pval);
	if (!ret)
	wdt_timer_period = pval;
	}

	wdt->dev = &pdev->dev;
	wdt->palmas = dev_get_drvdata(pdev->dev.parent);
	wdt->irq = palmas_irq_get_virq(wdt->palmas, PALMAS_WDT_IRQ);
	wdt_dev = &wdt->wdt_dev;

	wdt_dev->info = &palmas_wdt_info;
	wdt_dev->ops = &palmas_wdt_ops;
	wdt_dev->timeout = 128;
	wdt_dev->min_timeout = 1;
	wdt_dev->max_timeout = 128;
	watchdog_set_nowayout(wdt_dev, nowayout);
	watchdog_set_drvdata(wdt_dev, wdt);
	platform_set_drvdata(pdev, wdt);

	ret = request_threaded_irq(wdt->irq, NULL, palmas_wdt_irq,
	IRQF_ONESHOT \| IRQF_EARLY_RESUME,
	dev_name(&pdev->dev), wdt);
	if (ret < 0) {
	dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
	wdt->irq, ret);
	return ret;
	}

	ret = watchdog_register_device(wdt_dev);
	if (ret < 0) {
	dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
	return ret;
	}

	ret = palmas_read(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
	PALMAS_WATCHDOG, &regval);
	if (ret < 0) {
	dev_err(wdt->dev, "WATCHDOG read failed: %d\n", ret);
	goto scrub;
	}

	if (regval & PALMAS_WATCHDOG_LOCK) {
	dev_info(wdt->dev, "watchdog timer Locked\n");
	wdt->locked = true;
	} else {
	dev_info(wdt->dev, "watchdog timer unlocked\n");
	wdt->locked = false;
	}

	if (!wdt->locked) {
	ret = palmas_wdt_stop(wdt_dev);
	if (ret < 0) {
	dev_err(wdt->dev, "wdt stop failed: %d\n", ret);
	goto scrub;
	}
	}

	ret = palmas_update_bits(wdt->palmas, PALMAS_PMU_CONTROL_BASE,
	PALMAS_WATCHDOG, PALMAS_WATCHDOG_MODE, 0);
	if (ret < 0) {
	dev_err(wdt->dev, "WATCHDOG update failed: %d\n", ret);
	goto scrub;
	}

	if (wdt_timer_period) {
	ret = palmas_wdt_set_timeout(wdt_dev, wdt_timer_period);
	if (ret < 0) {
	dev_err(wdt->dev, "wdt set timeout failed: %d\n", ret);
	goto scrub;
	}
	if (!wdt->locked) {
	ret = palmas_wdt_start(wdt_dev);
	if (ret < 0) {
	dev_err(wdt->dev,
	"wdt start failed: %d\n", ret);
	goto scrub;
	}
	}
	}

	device_set_wakeup_capable(&pdev->dev, 1);
	return 0;
	scrub:
	free_irq(wdt->irq, wdt);
	watchdog_unregister_device(&wdt->wdt_dev);
	return ret;
	}

	static int palmas_wdt_remove(struct platform_device *pdev)
	{
	struct palmas_wdt *wdt = platform_get_drvdata(pdev);

	palmas_wdt_stop(&wdt->wdt_dev);
	watchdog_unregister_device(&wdt->wdt_dev);
	free_irq(wdt->irq, wdt);
	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int palmas_wdt_suspend(struct device *dev)
	{
	struct palmas_wdt *wdt = dev_get_drvdata(dev);
	int ret;

	if (device_may_wakeup(dev)) {
	enable_irq_wake(wdt->irq);
	} else if (wdt->timeout > 0) {
	ret = palmas_wdt_stop(&wdt->wdt_dev);
	if (ret < 0)
	dev_err(wdt->dev, "wdt stop failed: %d\n", ret);
	}
	return 0;
	}

	static int palmas_wdt_resume(struct device *dev)
	{
	struct palmas_wdt *wdt = dev_get_drvdata(dev);
	int ret;

	if (device_may_wakeup(dev)) {
	disable_irq_wake(wdt->irq);
	} else if (wdt->timeout > 0) {
	ret = palmas_wdt_start(&wdt->wdt_dev);
	if (ret < 0)
	dev_err(wdt->dev, "wdt start failed: %d\n", ret);
	}
	return 0;
	}
	#endif

	static const struct dev_pm_ops palmas_wdt_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(palmas_wdt_suspend, palmas_wdt_resume)
	};

	static struct of_device_id of_palmas_wdt_match_tbl[] = {
	{ .compatible = "ti,palmas-watchdog", },
	{},
	};
	MODULE_DEVICE_TABLE(of, of_palmas_wdt_match_tbl);

	static struct platform_driver palmas_wdt_driver = {
	.driver = {
	.name = "palmas-wdt",
	.owner = THIS_MODULE,
	.pm = &palmas_wdt_pm_ops,
	.of_match_table = of_palmas_wdt_match_tbl,
	},
	.probe = palmas_wdt_probe,
	.remove = palmas_wdt_remove,
	};

	static int __init palmas_wdt_init(void)
	{
	return platform_driver_register(&palmas_wdt_driver);
	}
	subsys_initcall(palmas_wdt_init);

	static void __exit palmas_wdt_exit(void)
	{
	platform_driver_unregister(&palmas_wdt_driver);
	}
	module_exit(palmas_wdt_exit);

	MODULE_ALIAS("platform:palmas-wdt");
	MODULE_DESCRIPTION("TI Palmas watchdog timer driver");
	MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
	MODULE_LICENSE("GPL v2");