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

// SPDX-License-Identifier: GPL-2.0+
/*
 * Watchdog driver for the wm8350
 *
 * Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com>
 */

#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
2e62c498	1	// SPDX-License-Identifier: GPL-2.0+
006948ba MB	2	/*
	3	* Watchdog driver for the wm8350
	4	*
	5	* Copyright (C) 2007, 2008 Wolfson Microelectronics <linux@wolfsonmicro.com>
006948ba MB	6	*/
006948ba MB	7
27c766aa JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	9
006948ba MB	10	#include <linux/module.h>
	11	#include <linux/moduleparam.h>
	12	#include <linux/types.h>
	13	#include <linux/kernel.h>
006948ba MB	14	#include <linux/platform_device.h>
	15	#include <linux/watchdog.h>
	16	#include <linux/uaccess.h>
	17	#include <linux/mfd/wm8350/core.h>
	18
86a1e189 WVS	19	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	20	module_param(nowayout, bool, 0);
006948ba MB	21	MODULE_PARM_DESC(nowayout,
	22	"Watchdog cannot be stopped once started (default="
	23	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	24
006948ba MB	25	static DEFINE_MUTEX(wdt_mutex);
	26
	27	static struct {
2e51d90f AL	28	unsigned int time; /* Seconds */
2e51d90f AL	29	u16 val; /* To be set in WM8350_SYSTEM_CONTROL_2 */
006948ba MB	30	} wm8350_wdt_cfgs[] = {
	31	{ 1, 0x02 },
	32	{ 2, 0x04 },
	33	{ 4, 0x05 },
	34	};
	35
2e51d90f AL	36	static int wm8350_wdt_set_timeout(struct watchdog_device *wdt_dev,
2e51d90f AL	37	unsigned int timeout)
006948ba	38	{
2e51d90f AL	39	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
2e51d90f AL	40	int ret, i;
006948ba MB	41	u16 reg;
006948ba MB	42
2e51d90f AL	43	for (i = 0; i < ARRAY_SIZE(wm8350_wdt_cfgs); i++)
	44	if (wm8350_wdt_cfgs[i].time == timeout)
	45	break;
	46	if (i == ARRAY_SIZE(wm8350_wdt_cfgs))
	47	return -EINVAL;
	48
006948ba MB	49	mutex_lock(&wdt_mutex);
	50	wm8350_reg_unlock(wm8350);
	51
	52	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	53	reg &= ~WM8350_WDOG_TO_MASK;
2e51d90f	54	reg \|= wm8350_wdt_cfgs[i].val;
006948ba MB	55	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	56
	57	wm8350_reg_lock(wm8350);
	58	mutex_unlock(&wdt_mutex);
	59
0197c1c4	60	wdt_dev->timeout = timeout;
006948ba MB	61	return ret;
	62	}
	63
2e51d90f	64	static int wm8350_wdt_start(struct watchdog_device *wdt_dev)
006948ba	65	{
2e51d90f	66	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
006948ba MB	67	int ret;
	68	u16 reg;
	69
	70	mutex_lock(&wdt_mutex);
	71	wm8350_reg_unlock(wm8350);
	72
	73	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	74	reg &= ~WM8350_WDOG_MODE_MASK;
	75	reg \|= 0x20;
	76	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	77
	78	wm8350_reg_lock(wm8350);
	79	mutex_unlock(&wdt_mutex);
	80
	81	return ret;
	82	}
	83
2e51d90f	84	static int wm8350_wdt_stop(struct watchdog_device *wdt_dev)
006948ba	85	{
2e51d90f	86	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
006948ba MB	87	int ret;
	88	u16 reg;
	89
	90	mutex_lock(&wdt_mutex);
	91	wm8350_reg_unlock(wm8350);
	92
	93	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	94	reg &= ~WM8350_WDOG_MODE_MASK;
	95	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	96
	97	wm8350_reg_lock(wm8350);
	98	mutex_unlock(&wdt_mutex);
	99
	100	return ret;
	101	}
	102
2e51d90f	103	static int wm8350_wdt_ping(struct watchdog_device *wdt_dev)
006948ba	104	{
2e51d90f	105	struct wm8350 *wm8350 = watchdog_get_drvdata(wdt_dev);
006948ba MB	106	int ret;
	107	u16 reg;
	108
	109	mutex_lock(&wdt_mutex);
	110
	111	reg = wm8350_reg_read(wm8350, WM8350_SYSTEM_CONTROL_2);
	112	ret = wm8350_reg_write(wm8350, WM8350_SYSTEM_CONTROL_2, reg);
	113
	114	mutex_unlock(&wdt_mutex);
	115
	116	return ret;
	117	}
	118
2e51d90f	119	static const struct watchdog_info wm8350_wdt_info = {
006948ba MB	120	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	121	.identity = "WM8350 Watchdog",
	122	};
	123
2e51d90f	124	static const struct watchdog_ops wm8350_wdt_ops = {
006948ba	125	.owner = THIS_MODULE,
2e51d90f AL	126	.start = wm8350_wdt_start,
	127	.stop = wm8350_wdt_stop,
	128	.ping = wm8350_wdt_ping,
	129	.set_timeout = wm8350_wdt_set_timeout,
006948ba MB	130	};
006948ba MB	131
2e51d90f AL	132	static struct watchdog_device wm8350_wdt = {
	133	.info = &wm8350_wdt_info,
	134	.ops = &wm8350_wdt_ops,
	135	.timeout = 4,
	136	.min_timeout = 1,
	137	.max_timeout = 4,
006948ba MB	138	};
006948ba MB	139
2d991a16	140	static int wm8350_wdt_probe(struct platform_device *pdev)
006948ba MB	141	{
	142	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
	143
	144	if (!wm8350) {
cfca31ce	145	pr_err("No driver data supplied\n");
006948ba MB	146	return -ENODEV;
	147	}
	148
2e51d90f AL	149	watchdog_set_nowayout(&wm8350_wdt, nowayout);
2e51d90f AL	150	watchdog_set_drvdata(&wm8350_wdt, wm8350);
6551881c	151	wm8350_wdt.parent = &pdev->dev;
006948ba	152
2e51d90f AL	153	/* Default to 4s timeout */
2e51d90f AL	154	wm8350_wdt_set_timeout(&wm8350_wdt, 4);
006948ba	155
2e51d90f	156	return watchdog_register_device(&wm8350_wdt);
006948ba MB	157	}
006948ba MB	158
4b12b896	159	static int wm8350_wdt_remove(struct platform_device *pdev)
006948ba	160	{
2e51d90f	161	watchdog_unregister_device(&wm8350_wdt);
006948ba MB	162	return 0;
	163	}
	164
	165	static struct platform_driver wm8350_wdt_driver = {
	166	.probe = wm8350_wdt_probe,
82268714	167	.remove = wm8350_wdt_remove,
006948ba MB	168	.driver = {
	169	.name = "wm8350-wdt",
	170	},
	171	};
	172
216f3ad9	173	module_platform_driver(wm8350_wdt_driver);
006948ba MB	174
	175	MODULE_AUTHOR("Mark Brown");
	176	MODULE_DESCRIPTION("WM8350 Watchdog");
	177	MODULE_LICENSE("GPL");
	178	MODULE_ALIAS("platform:wm8350-wdt");