[deliverable/linux.git] / drivers / watchdog / da9063_wdt.c

/*
 * Watchdog driver for DA9063 PMICs.
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: Mariusz Wojtasik <mariusz.wojtasik@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/kernel.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/mfd/da9063/registers.h>
#include <linux/mfd/da9063/core.h>
#include <linux/reboot.h>
#include <linux/regmap.h>

/*
 * Watchdog selector to timeout in seconds.
 *   0: WDT disabled;
 *   others: timeout = 2048 ms * 2^(TWDSCALE-1).
 */
static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
#define DA9063_TWDSCALE_DISABLE		0
#define DA9063_TWDSCALE_MIN		1
#define DA9063_TWDSCALE_MAX		(ARRAY_SIZE(wdt_timeout) - 1)
#define DA9063_WDT_MIN_TIMEOUT		wdt_timeout[DA9063_TWDSCALE_MIN]
#define DA9063_WDT_MAX_TIMEOUT		wdt_timeout[DA9063_TWDSCALE_MAX]
#define DA9063_WDG_TIMEOUT		wdt_timeout[3]

struct da9063_watchdog {
	struct da9063 *da9063;
	struct watchdog_device wdtdev;
	struct notifier_block restart_handler;
};

static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
{
	unsigned int i;

	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
		if (wdt_timeout[i] >= secs)
			return i;
	}

	return DA9063_TWDSCALE_MAX;
}

static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
{
	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
				  DA9063_TWDSCALE_MASK, regval);
}

static int da9063_wdt_start(struct watchdog_device *wdd)
{
	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	unsigned int selector;
	int ret;

	selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout);
	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
	if (ret)
		dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
			ret);

	return ret;
}

static int da9063_wdt_stop(struct watchdog_device *wdd)
{
	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D,
				 DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
	if (ret)
		dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
			  ret);

	return ret;
}

static int da9063_wdt_ping(struct watchdog_device *wdd)
{
	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
			   DA9063_WATCHDOG);
	if (ret)
		dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n",
			  ret);

	return ret;
}

static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
				  unsigned int timeout)
{
	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	unsigned int selector;
	int ret;

	selector = da9063_wdt_timeout_to_sel(timeout);
	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
	if (ret)
		dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
			ret);
	else
		wdd->timeout = wdt_timeout[selector];

	return ret;
}

static int da9063_wdt_restart_handler(struct notifier_block *this,
				      unsigned long mode, void *cmd)
{
	struct da9063_watchdog *wdt = container_of(this,
						   struct da9063_watchdog,
						   restart_handler);
	int ret;

	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
			   DA9063_SHUTDOWN);
	if (ret)
		dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n",
			  ret);

	return NOTIFY_DONE;
}

static const struct watchdog_info da9063_watchdog_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
	.identity = "DA9063 Watchdog",
};

static const struct watchdog_ops da9063_watchdog_ops = {
	.owner = THIS_MODULE,
	.start = da9063_wdt_start,
	.stop = da9063_wdt_stop,
	.ping = da9063_wdt_ping,
	.set_timeout = da9063_wdt_set_timeout,
};

static int da9063_wdt_probe(struct platform_device *pdev)
{
	int ret;
	struct da9063 *da9063;
	struct da9063_watchdog *wdt;

	if (!pdev->dev.parent)
		return -EINVAL;

	da9063 = dev_get_drvdata(pdev->dev.parent);
	if (!da9063)
		return -EINVAL;

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

	wdt->da9063 = da9063;

	wdt->wdtdev.info = &da9063_watchdog_info;
	wdt->wdtdev.ops = &da9063_watchdog_ops;
	wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT;
	wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT;
	wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT;

	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;

	watchdog_set_drvdata(&wdt->wdtdev, wdt);
	dev_set_drvdata(&pdev->dev, wdt);

	ret = watchdog_register_device(&wdt->wdtdev);
	if (ret)
		return ret;

	wdt->restart_handler.notifier_call = da9063_wdt_restart_handler;
	wdt->restart_handler.priority = 128;
	ret = register_restart_handler(&wdt->restart_handler);
	if (ret)
		dev_err(wdt->da9063->dev,
			"Failed to register restart handler (err = %d)\n", ret);

	return 0;
}

static int da9063_wdt_remove(struct platform_device *pdev)
{
	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);

	unregister_restart_handler(&wdt->restart_handler);

	watchdog_unregister_device(&wdt->wdtdev);

	return 0;
}

static struct platform_driver da9063_wdt_driver = {
	.probe = da9063_wdt_probe,
	.remove = da9063_wdt_remove,
	.driver = {
		.name = DA9063_DRVNAME_WATCHDOG,
	},
};
module_platform_driver(da9063_wdt_driver);

MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);
Commit	Line	Data
5e9c16e3 KG	1	/*
	2	* Watchdog driver for DA9063 PMICs.
	3	*
	4	* Copyright(c) 2012 Dialog Semiconductor Ltd.
	5	*
	6	* Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/watchdog.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/uaccess.h>
	19	#include <linux/slab.h>
	20	#include <linux/delay.h>
	21	#include <linux/mfd/da9063/registers.h>
	22	#include <linux/mfd/da9063/core.h>
396f163c	23	#include <linux/reboot.h>
5e9c16e3 KG	24	#include <linux/regmap.h>
	25
	26	/*
	27	* Watchdog selector to timeout in seconds.
	28	* 0: WDT disabled;
	29	* others: timeout = 2048 ms * 2^(TWDSCALE-1).
	30	*/
	31	static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
	32	#define DA9063_TWDSCALE_DISABLE 0
	33	#define DA9063_TWDSCALE_MIN 1
	34	#define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
	35	#define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN]
	36	#define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX]
	37	#define DA9063_WDG_TIMEOUT wdt_timeout[3]
	38
	39	struct da9063_watchdog {
	40	struct da9063 *da9063;
	41	struct watchdog_device wdtdev;
396f163c	42	struct notifier_block restart_handler;
5e9c16e3 KG	43	};
	44
	45	static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
	46	{
	47	unsigned int i;
	48
	49	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
	50	if (wdt_timeout[i] >= secs)
	51	return i;
	52	}
	53
	54	return DA9063_TWDSCALE_MAX;
	55	}
	56
	57	static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
	58	{
	59	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	60	DA9063_TWDSCALE_MASK, regval);
	61	}
	62
	63	static int da9063_wdt_start(struct watchdog_device *wdd)
	64	{
	65	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	66	unsigned int selector;
	67	int ret;
	68
	69	selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout);
	70	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
	71	if (ret)
	72	dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
	73	ret);
	74
	75	return ret;
	76	}
	77
	78	static int da9063_wdt_stop(struct watchdog_device *wdd)
	79	{
	80	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	81	int ret;
	82
	83	ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D,
	84	DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
	85	if (ret)
	86	dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
	87	ret);
	88
	89	return ret;
	90	}
	91
	92	static int da9063_wdt_ping(struct watchdog_device *wdd)
	93	{
	94	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	95	int ret;
	96
	97	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
	98	DA9063_WATCHDOG);
	99	if (ret)
	100	dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n",
	101	ret);
	102
	103	return ret;
	104	}
	105
	106	static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
107	unsigned int timeout)
108	{
109	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
110	unsigned int selector;
111	int ret;
112
113	selector = da9063_wdt_timeout_to_sel(timeout);
114	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
115	if (ret)
116	dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
117	ret);
118	else
119	wdd->timeout = wdt_timeout[selector];
120
121	return ret;
122	}
123
396f163c GU	124	static int da9063_wdt_restart_handler(struct notifier_block *this,
	125	unsigned long mode, void *cmd)
	126	{
	127	struct da9063_watchdog *wdt = container_of(this,
	128	struct da9063_watchdog,
	129	restart_handler);
	130	int ret;
	131
	132	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
	133	DA9063_SHUTDOWN);
	134	if (ret)
	135	dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n",
	136	ret);
	137
	138	return NOTIFY_DONE;
	139	}
	140
5e9c16e3 KG	141	static const struct watchdog_info da9063_watchdog_info = {
	142	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	143	.identity = "DA9063 Watchdog",
	144	};
	145
	146	static const struct watchdog_ops da9063_watchdog_ops = {
	147	.owner = THIS_MODULE,
	148	.start = da9063_wdt_start,
	149	.stop = da9063_wdt_stop,
	150	.ping = da9063_wdt_ping,
	151	.set_timeout = da9063_wdt_set_timeout,
	152	};
	153
	154	static int da9063_wdt_probe(struct platform_device *pdev)
	155	{
	156	int ret;
	157	struct da9063 *da9063;
	158	struct da9063_watchdog *wdt;
	159
	160	if (!pdev->dev.parent)
	161	return -EINVAL;
	162
	163	da9063 = dev_get_drvdata(pdev->dev.parent);
	164	if (!da9063)
	165	return -EINVAL;
	166
	167	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	168	if (!wdt)
	169	return -ENOMEM;
	170
	171	wdt->da9063 = da9063;
	172
	173	wdt->wdtdev.info = &da9063_watchdog_info;
	174	wdt->wdtdev.ops = &da9063_watchdog_ops;
	175	wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT;
	176	wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT;
	177	wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT;
	178
	179	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
	180
	181	watchdog_set_drvdata(&wdt->wdtdev, wdt);
	182	dev_set_drvdata(&pdev->dev, wdt);
	183
	184	ret = watchdog_register_device(&wdt->wdtdev);
396f163c GU	185	if (ret)
396f163c GU	186	return ret;
5e9c16e3	187
396f163c GU	188	wdt->restart_handler.notifier_call = da9063_wdt_restart_handler;
	189	wdt->restart_handler.priority = 128;
	190	ret = register_restart_handler(&wdt->restart_handler);
	191	if (ret)
	192	dev_err(wdt->da9063->dev,
	193	"Failed to register restart handler (err = %d)\n", ret);
	194
	195	return 0;
5e9c16e3 KG	196	}
	197
	198	static int da9063_wdt_remove(struct platform_device *pdev)
	199	{
	200	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);
	201
396f163c GU	202	unregister_restart_handler(&wdt->restart_handler);
396f163c GU	203
5e9c16e3 KG	204	watchdog_unregister_device(&wdt->wdtdev);
	205
	206	return 0;
	207	}
	208
	209	static struct platform_driver da9063_wdt_driver = {
	210	.probe = da9063_wdt_probe,
	211	.remove = da9063_wdt_remove,
	212	.driver = {
	213	.name = DA9063_DRVNAME_WATCHDOG,
	214	},
	215	};
	216	module_platform_driver(da9063_wdt_driver);
	217
	218	MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
	219	MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
	220	MODULE_LICENSE("GPL");
	221	MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);