[linux-2.6-block.git] / drivers / watchdog / wm8350_wdt.c

/*
 * Watchdog driver for the wm8350
 *
 * Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/mfd/wm8350/core.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) ")");

static DEFINE_MUTEX(wdt_mutex);

static struct {
	unsigned int time;  /* Seconds */
	u16 val;	    /* To be set in WM8350_SYSTEM_CONTROL_2 */
} wm8350_wdt_cfgs[] = {
	{ 1, 0x02 },
	{ 2, 0x04 },
	{ 4, 0x05 },
};

static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev,
				  unsigned int timeout)
{
	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
	int ret, i;
	u16 reg;

	for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
		if (wm8350_wdt_cfgs[i].time == timeout)
			break;
	if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
		return -EINVAL;

	mutex_lock(&wdt_mutex);
	wm8350_reg_unlock(wm8350);

	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	reg &= ~WM8350_WDOG_TO_MASK;
	reg |= wm8350_wdt_cfgs[i].val;
	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);

	wm8350_reg_lock(wm8350);
	mutex_unlock(&wdt_mutex);

	wdt_dev->timeout = timeout;
	return ret;
}

static int wm8350_wdt_start(struct watchdog_device *wdt_dev)
{
	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
	int ret;
	u16 reg;

	mutex_lock(&wdt_mutex);
	wm8350_reg_unlock(wm8350);

	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	reg &= ~WM8350_WDOG_MODE_MASK;
	reg |= 0x20;
	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);

	wm8350_reg_lock(wm8350);
	mutex_unlock(&wdt_mutex);

	return ret;
}

static int wm8350_wdt_stop(struct watchdog_device *wdt_dev)
{
	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
	int ret;
	u16 reg;

	mutex_lock(&wdt_mutex);
	wm8350_reg_unlock(wm8350);

	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	reg &= ~WM8350_WDOG_MODE_MASK;
	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);

	wm8350_reg_lock(wm8350);
	mutex_unlock(&wdt_mutex);

	return ret;
}

static int wm8350_wdt_ping(struct watchdog_device *wdt_dev)
{
	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
	int ret;
	u16 reg;

	mutex_lock(&wdt_mutex);

	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);

	mutex_unlock(&wdt_mutex);

	return ret;
}

static const struct watchdog_info wm8350_wdt_info = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
	.identity = "WM8350 Watchdog",
};

static const struct watchdog_ops wm8350_wdt_ops = {
	.owner = THIS_MODULE,
	.start = wm8350_wdt_start,
	.stop = wm8350_wdt_stop,
	.ping = wm8350_wdt_ping,
	.set_timeout = wm8350_wdt_set_timeout,
};

static struct watchdog_device wm8350_wdt = {
	.info = &wm8350_wdt_info,
	.ops = &wm8350_wdt_ops,
	.timeout = 4,
	.min_timeout = 1,
	.max_timeout = 4,
};

static int wm8350_wdt_probe(struct platform_device *pdev)
{
	struct wm8350 *wm8350 = platform_get_drvdata(pdev);

	if (!wm8350) {
		pr_err("No driver data supplied\n");
		return -ENODEV;
	}

	watchdog_set_nowayout(&wm8350_wdt, nowayout);
	watchdog_set_drvdata(&wm8350_wdt, wm8350);
	wm8350_wdt.parent = &pdev->dev;

	/* Default to 4s timeout */
	wm8350_wdt_set_timeout(&wm8350_wdt, 4);

	return watchdog_register_device(&wm8350_wdt);
}

static int wm8350_wdt_remove(struct platform_device *pdev)
{
	watchdog_unregister_device(&wm8350_wdt);
	return 0;
}

static struct platform_driver wm8350_wdt_driver = {
	.probe = wm8350_wdt_probe,
	.remove = wm8350_wdt_remove,
	.driver = {
		.name = "wm8350-wdt",
	},
};

module_platform_driver(wm8350_wdt_driver);

MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM8350 Watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8350-wdt");
Commit	Line	Data
006948ba MB	1	/*
	2	* Watchdog driver for the wm8350
	3	*
	4	* Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation
	9	*/
	10
27c766aa JP	11	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	12
006948ba MB	13	#include <linux/module.h>
	14	#include <linux/moduleparam.h>
	15	#include <linux/types.h>
	16	#include <linux/kernel.h>
006948ba MB	17	#include <linux/platform_device.h>
	18	#include <linux/watchdog.h>
	19	#include <linux/uaccess.h>
	20	#include <linux/mfd/wm8350/core.h>
	21
86a1e189 WVS	22	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	23	module_param(nowayout, bool, 0);
006948ba MB	24	MODULE_PARM_DESC(nowayout,
	25	"Watchdog cannot be stopped once started (default="
	26	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	27
006948ba MB	28	static DEFINE_MUTEX(wdt_mutex);
	29
	30	static struct {
2e51d90f AL	31	unsigned int time; /* Seconds */
2e51d90f AL	32	u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */
006948ba MB	33	} wm8350_wdt_cfgs[] = {
	34	{ 1, 0x02 },
	35	{ 2, 0x04 },
	36	{ 4, 0x05 },
	37	};
	38
2e51d90f AL	39	static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev,
2e51d90f AL	40	unsigned int timeout)
006948ba	41	{
2e51d90f AL	42	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
2e51d90f AL	43	int ret, i;
006948ba MB	44	u16 reg;
006948ba MB	45
2e51d90f AL	46	for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
	47	if (wm8350_wdt_cfgs[i].time == timeout)
	48	break;
	49	if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
	50	return -EINVAL;
	51
006948ba MB	52	mutex_lock(&wdt_mutex);
	53	wm8350_reg_unlock(wm8350);
	54
	55	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	56	reg &= ~WM8350_WDOG_TO_MASK;
2e51d90f	57	reg \|= wm8350_wdt_cfgs[i].val;
006948ba MB	58	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	59
	60	wm8350_reg_lock(wm8350);
	61	mutex_unlock(&wdt_mutex);
	62
0197c1c4	63	wdt_dev->timeout = timeout;
006948ba MB	64	return ret;
	65	}
	66
2e51d90f	67	static int wm8350_wdt_start(struct watchdog_device *wdt_dev)
006948ba	68	{
2e51d90f	69	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
006948ba MB	70	int ret;
	71	u16 reg;
	72
	73	mutex_lock(&wdt_mutex);
	74	wm8350_reg_unlock(wm8350);
	75
	76	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	77	reg &= ~WM8350_WDOG_MODE_MASK;
	78	reg \|= 0x20;
	79	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	80
	81	wm8350_reg_lock(wm8350);
	82	mutex_unlock(&wdt_mutex);
	83
	84	return ret;
	85	}
	86
2e51d90f	87	static int wm8350_wdt_stop(struct watchdog_device *wdt_dev)
006948ba	88	{
2e51d90f	89	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
006948ba MB	90	int ret;
	91	u16 reg;
	92
	93	mutex_lock(&wdt_mutex);
	94	wm8350_reg_unlock(wm8350);
	95
	96	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	97	reg &= ~WM8350_WDOG_MODE_MASK;
	98	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	99
	100	wm8350_reg_lock(wm8350);
	101	mutex_unlock(&wdt_mutex);
	102
	103	return ret;
	104	}
	105
2e51d90f	106	static int wm8350_wdt_ping(struct watchdog_device *wdt_dev)
006948ba	107	{
2e51d90f	108	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
006948ba MB	109	int ret;
	110	u16 reg;
	111
	112	mutex_lock(&wdt_mutex);
	113
	114	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	115	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	116
	117	mutex_unlock(&wdt_mutex);
	118
	119	return ret;
	120	}
	121
2e51d90f	122	static const struct watchdog_info wm8350_wdt_info = {
006948ba MB	123	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	124	.identity = "WM8350 Watchdog",
	125	};
	126
2e51d90f	127	static const struct watchdog_ops wm8350_wdt_ops = {
006948ba	128	.owner = THIS_MODULE,
2e51d90f AL	129	.start = wm8350_wdt_start,
	130	.stop = wm8350_wdt_stop,
	131	.ping = wm8350_wdt_ping,
	132	.set_timeout = wm8350_wdt_set_timeout,
006948ba MB	133	};
006948ba MB	134
2e51d90f AL	135	static struct watchdog_device wm8350_wdt = {
	136	.info = &wm8350_wdt_info,
	137	.ops = &wm8350_wdt_ops,
	138	.timeout = 4,
	139	.min_timeout = 1,
	140	.max_timeout = 4,
006948ba MB	141	};
006948ba MB	142
2d991a16	143	static int wm8350_wdt_probe(struct platform_device *pdev)
006948ba MB	144	{
	145	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
	146
	147	if (!wm8350) {
cfca31ce	148	pr_err("No driver data supplied\n");
006948ba MB	149	return -ENODEV;
	150	}
	151
2e51d90f AL	152	watchdog_set_nowayout(&wm8350_wdt, nowayout);
2e51d90f AL	153	watchdog_set_drvdata(&wm8350_wdt, wm8350);
6551881c	154	wm8350_wdt.parent = &pdev->dev;
006948ba	155
2e51d90f AL	156	/* Default to 4s timeout */
2e51d90f AL	157	wm8350_wdt_set_timeout(&wm8350_wdt, 4);
006948ba	158
2e51d90f	159	return watchdog_register_device(&wm8350_wdt);
006948ba MB	160	}
006948ba MB	161
4b12b896	162	static int wm8350_wdt_remove(struct platform_device *pdev)
006948ba	163	{
2e51d90f	164	watchdog_unregister_device(&wm8350_wdt);
006948ba MB	165	return 0;
	166	}
	167
	168	static struct platform_driver wm8350_wdt_driver = {
	169	.probe = wm8350_wdt_probe,
82268714	170	.remove = wm8350_wdt_remove,
006948ba MB	171	.driver = {
	172	.name = "wm8350-wdt",
	173	},
	174	};
	175
216f3ad9	176	module_platform_driver(wm8350_wdt_driver);
006948ba MB	177
	178	MODULE_AUTHOR("Mark Brown");
	179	MODULE_DESCRIPTION("WM8350 Watchdog");
	180	MODULE_LICENSE("GPL");
	181	MODULE_ALIAS("platform:wm8350-wdt");