[mirror_ubuntu-artful-kernel.git] / drivers / watchdog / stmp3xxx_rtc_wdt.c

/*
 * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
 *
 * Author: Wolfram Sang <w.sang@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);

	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 <w.sang@pengutronix.de>");
Commit	Line	Data
de6303ab WS	1	/*
	2	* Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
	3	*
	4	* Author: Wolfram Sang <w.sang@pengutronix.de>
	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);
	79
	80	ret = watchdog_register_device(&stmp3xxx_wdd);
	81	if (ret < 0) {
	82	dev_err(&pdev->dev, "cannot register watchdog device\n");
	83	return ret;
	84	}
	85
	86	dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
	87	stmp3xxx_wdd.timeout);
	88	return 0;
	89	}
	90
	91	static int stmp3xxx_wdt_remove(struct platform_device *pdev)
	92	{
	93	watchdog_unregister_device(&stmp3xxx_wdd);
	94	return 0;
	95	}
	96
3281b85c JU	97	static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
	98	{
	99	struct watchdog_device *wdd = &stmp3xxx_wdd;
	100
	101	if (watchdog_active(wdd))
	102	return wdt_stop(wdd);
	103
	104	return 0;
	105	}
	106
	107	static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
	108	{
	109	struct watchdog_device *wdd = &stmp3xxx_wdd;
	110
	111	if (watchdog_active(wdd))
	112	return wdt_start(wdd);
	113
	114	return 0;
	115	}
	116
	117	static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
	118	stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
	119
de6303ab WS	120	static struct platform_driver stmp3xxx_wdt_driver = {
	121	.driver = {
	122	.name = "stmp3xxx_rtc_wdt",
3281b85c	123	.pm = &stmp3xxx_wdt_pm_ops,
de6303ab WS	124	},
	125	.probe = stmp3xxx_wdt_probe,
	126	.remove = stmp3xxx_wdt_remove,
	127	};
	128	module_platform_driver(stmp3xxx_wdt_driver);
	129
	130	MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
	131	MODULE_LICENSE("GPL v2");
	132	MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");