[linux-2.6-block.git] / drivers / watchdog / stmp3xxx_rtc_wdt.c

/*
 * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
 *
 * Author: Wolfram Sang <kernel@pengutronix.de>
 *
 * Copyright (C) 2011-12 Wolfram Sang, Pengutronix
 *
 * 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.
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/stmp3xxx_rtc_wdt.h>

#define WDOG_TICK_RATE 1000 /* 1 kHz clock */
#define STMP3XXX_DEFAULT_TIMEOUT 19
#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)

static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
module_param(heartbeat, uint, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
		 __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
		 __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));

static int wdt_start(struct watchdog_device *wdd)
{
	struct device *dev = watchdog_get_drvdata(wdd);
	struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);

	pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
	return 0;
}

static int wdt_stop(struct watchdog_device *wdd)
{
	struct device *dev = watchdog_get_drvdata(wdd);
	struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);

	pdata->wdt_set_timeout(dev->parent, 0);
	return 0;
}

static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
{
	wdd->timeout = new_timeout;
	return wdt_start(wdd);
}

static const struct watchdog_info stmp3xxx_wdt_ident = {
	.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
	.identity = "STMP3XXX RTC Watchdog",
};

static const struct watchdog_ops stmp3xxx_wdt_ops = {
	.owner = THIS_MODULE,
	.start = wdt_start,
	.stop = wdt_stop,
	.set_timeout = wdt_set_timeout,
};

static struct watchdog_device stmp3xxx_wdd = {
	.info = &stmp3xxx_wdt_ident,
	.ops = &stmp3xxx_wdt_ops,
	.min_timeout = 1,
	.max_timeout = STMP3XXX_MAX_TIMEOUT,
	.status = WATCHDOG_NOWAYOUT_INIT_STATUS,
};

static int stmp3xxx_wdt_probe(struct platform_device *pdev)
{
	int ret;

	watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);

	stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
	stmp3xxx_wdd.parent = &pdev->dev;

	ret = watchdog_register_device(&stmp3xxx_wdd);
	if (ret < 0) {
		dev_err(&pdev->dev, "cannot register watchdog device\n");
		return ret;
	}

	dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
			stmp3xxx_wdd.timeout);
	return 0;
}

static int stmp3xxx_wdt_remove(struct platform_device *pdev)
{
	watchdog_unregister_device(&stmp3xxx_wdd);
	return 0;
}

static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
{
	struct watchdog_device *wdd = &stmp3xxx_wdd;

	if (watchdog_active(wdd))
		return wdt_stop(wdd);

	return 0;
}

static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
{
	struct watchdog_device *wdd = &stmp3xxx_wdd;

	if (watchdog_active(wdd))
		return wdt_start(wdd);

	return 0;
}

static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
			 stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);

static struct platform_driver stmp3xxx_wdt_driver = {
	.driver = {
		.name = "stmp3xxx_rtc_wdt",
		.pm = &stmp3xxx_wdt_pm_ops,
	},
	.probe = stmp3xxx_wdt_probe,
	.remove = stmp3xxx_wdt_remove,
};
module_platform_driver(stmp3xxx_wdt_driver);

MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
Commit	Line	Data
de6303ab WS	1	/*
	2	* Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
	3	*
cf82f52d	4	* Author: Wolfram Sang <kernel@pengutronix.de>
de6303ab WS	5	*
	6	* Copyright (C) 2011-12 Wolfram Sang, Pengutronix
	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 version 2 as published by
	10	* the Free Software Foundation.
	11	*/
de6303ab WS	12	#include <linux/kernel.h>
de6303ab WS	13	#include <linux/module.h>
de6303ab WS	14	#include <linux/watchdog.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/stmp3xxx_rtc_wdt.h>
	17
	18	#define WDOG_TICK_RATE 1000 /* 1 kHz clock */
	19	#define STMP3XXX_DEFAULT_TIMEOUT 19
	20	#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
	21
	22	static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
	23	module_param(heartbeat, uint, 0);
	24	MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
	25	__MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
	26	__MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
	27
	28	static int wdt_start(struct watchdog_device *wdd)
	29	{
	30	struct device *dev = watchdog_get_drvdata(wdd);
bc8fdfbe	31	struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
de6303ab WS	32
	33	pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
	34	return 0;
	35	}
	36
	37	static int wdt_stop(struct watchdog_device *wdd)
	38	{
	39	struct device *dev = watchdog_get_drvdata(wdd);
bc8fdfbe	40	struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
de6303ab WS	41
	42	pdata->wdt_set_timeout(dev->parent, 0);
	43	return 0;
	44	}
	45
	46	static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
	47	{
	48	wdd->timeout = new_timeout;
	49	return wdt_start(wdd);
	50	}
	51
	52	static const struct watchdog_info stmp3xxx_wdt_ident = {
	53	.options = WDIOF_MAGICCLOSE \| WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	54	.identity = "STMP3XXX RTC Watchdog",
	55	};
	56
	57	static const struct watchdog_ops stmp3xxx_wdt_ops = {
	58	.owner = THIS_MODULE,
	59	.start = wdt_start,
	60	.stop = wdt_stop,
	61	.set_timeout = wdt_set_timeout,
	62	};
	63
	64	static struct watchdog_device stmp3xxx_wdd = {
	65	.info = &stmp3xxx_wdt_ident,
	66	.ops = &stmp3xxx_wdt_ops,
	67	.min_timeout = 1,
	68	.max_timeout = STMP3XXX_MAX_TIMEOUT,
	69	.status = WATCHDOG_NOWAYOUT_INIT_STATUS,
	70	};
	71
	72	static int stmp3xxx_wdt_probe(struct platform_device *pdev)
	73	{
	74	int ret;
	75
	76	watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);
	77
	78	stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
6551881c	79	stmp3xxx_wdd.parent = &pdev->dev;
de6303ab WS	80
	81	ret = watchdog_register_device(&stmp3xxx_wdd);
	82	if (ret < 0) {
	83	dev_err(&pdev->dev, "cannot register watchdog device\n");
	84	return ret;
	85	}
	86
	87	dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
	88	stmp3xxx_wdd.timeout);
	89	return 0;
	90	}
	91
	92	static int stmp3xxx_wdt_remove(struct platform_device *pdev)
	93	{
	94	watchdog_unregister_device(&stmp3xxx_wdd);
	95	return 0;
	96	}
	97
3281b85c JU	98	static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
	99	{
	100	struct watchdog_device *wdd = &stmp3xxx_wdd;
	101
	102	if (watchdog_active(wdd))
	103	return wdt_stop(wdd);
	104
	105	return 0;
	106	}
	107
	108	static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
	109	{
	110	struct watchdog_device *wdd = &stmp3xxx_wdd;
	111
	112	if (watchdog_active(wdd))
	113	return wdt_start(wdd);
	114
	115	return 0;
	116	}
	117
	118	static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
	119	stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
	120
de6303ab WS	121	static struct platform_driver stmp3xxx_wdt_driver = {
	122	.driver = {
	123	.name = "stmp3xxx_rtc_wdt",
3281b85c	124	.pm = &stmp3xxx_wdt_pm_ops,
de6303ab WS	125	},
	126	.probe = stmp3xxx_wdt_probe,
	127	.remove = stmp3xxx_wdt_remove,
	128	};
	129	module_platform_driver(stmp3xxx_wdt_driver);
	130
	131	MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
	132	MODULE_LICENSE("GPL v2");
cf82f52d	133	MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");