[linux-2.6-block.git] / drivers / watchdog / da9063_wdt.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Watchdog driver for DA9063 PMICs.
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
 *
 */

#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/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]
#define DA9063_RESET_PROTECTION_MS	256

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;
}

/*
 * Return 0 if watchdog is disabled, else non zero.
 */
static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
{
	unsigned int val;

	regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);

	return val & DA9063_TWDSCALE_MASK;
}

static int da9063_wdt_disable_timer(struct da9063 *da9063)
{
	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
				  DA9063_TWDSCALE_MASK,
				  DA9063_TWDSCALE_DISABLE);
}

static int
da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout)
{
	unsigned int regval;
	int ret;

	/*
	 * The watchdog triggers a reboot if a timeout value is already
	 * programmed because the timeout value combines two functions
	 * in one: indicating the counter limit and starting the watchdog.
	 * The watchdog must be disabled to be able to change the timeout
	 * value if the watchdog is already running. Then we can set the
	 * new timeout value which enables the watchdog again.
	 */
	ret = da9063_wdt_disable_timer(da9063);
	if (ret)
		return ret;

	usleep_range(150, 300);
	regval = da9063_wdt_timeout_to_sel(timeout);

	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 *da9063 = watchdog_get_drvdata(wdd);
	int ret;

	ret = da9063_wdt_update_timeout(da9063, wdd->timeout);
	if (ret)
		dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
			ret);

	return ret;
}

static int da9063_wdt_stop(struct watchdog_device *wdd)
{
	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
	int ret;

	ret = da9063_wdt_disable_timer(da9063);
	if (ret)
		dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
			  ret);

	return ret;
}

static int da9063_wdt_ping(struct watchdog_device *wdd)
{
	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
	int ret;

	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
			   DA9063_WATCHDOG);
	if (ret)
		dev_alert(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 *da9063 = watchdog_get_drvdata(wdd);
	int ret = 0;

	/*
	 * There are two cases when a set_timeout() will be called:
	 * 1. The watchdog is off and someone wants to set the timeout for the
	 *    further use.
	 * 2. The watchdog is already running and a new timeout value should be
	 *    set.
	 *
	 * The watchdog can't store a timeout value not equal zero without
	 * enabling the watchdog, so the timeout must be buffered by the driver.
	 */
	if (watchdog_active(wdd))
		ret = da9063_wdt_update_timeout(da9063, timeout);

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

	return ret;
}

static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
			      void *data)
{
	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
	int ret;

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

	return ret;
}

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,
	.restart = da9063_wdt_restart,
};

static int da9063_wdt_probe(struct platform_device *pdev)
{
	struct da9063 *da9063;
	struct watchdog_device *wdd;

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

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

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

	wdd->info = &da9063_watchdog_info;
	wdd->ops = &da9063_watchdog_ops;
	wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
	wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
	wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
	wdd->timeout = DA9063_WDG_TIMEOUT;
	wdd->parent = &pdev->dev;

	wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;

	watchdog_set_restart_priority(wdd, 128);

	watchdog_set_drvdata(wdd, da9063);

	/* Change the timeout to the default value if the watchdog is running */
	if (da9063_wdt_is_running(da9063)) {
		da9063_wdt_update_timeout(da9063, DA9063_WDG_TIMEOUT);
		set_bit(WDOG_HW_RUNNING, &wdd->status);
	}

	return devm_watchdog_register_device(&pdev->dev, wdd);
}

static struct platform_driver da9063_wdt_driver = {
	.probe = da9063_wdt_probe,
	.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
2e62c498	1	// SPDX-License-Identifier: GPL-2.0+
5e9c16e3 KG	2	/*
	3	* Watchdog driver for DA9063 PMICs.
	4	*
	5	* Copyright(c) 2012 Dialog Semiconductor Ltd.
	6	*
	7	* Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
	8	*
5e9c16e3 KG	9	*/
	10
	11	#include <linux/kernel.h>
	12	#include <linux/module.h>
	13	#include <linux/watchdog.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/uaccess.h>
	16	#include <linux/slab.h>
	17	#include <linux/delay.h>
	18	#include <linux/mfd/da9063/registers.h>
	19	#include <linux/mfd/da9063/core.h>
	20	#include <linux/regmap.h>
	21
	22	/*
	23	* Watchdog selector to timeout in seconds.
	24	* 0: WDT disabled;
	25	* others: timeout = 2048 ms * 2^(TWDSCALE-1).
	26	*/
	27	static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
	28	#define DA9063_TWDSCALE_DISABLE 0
	29	#define DA9063_TWDSCALE_MIN 1
	30	#define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
	31	#define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN]
	32	#define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX]
	33	#define DA9063_WDG_TIMEOUT wdt_timeout[3]
a74cab40	34	#define DA9063_RESET_PROTECTION_MS 256
5e9c16e3	35
5e9c16e3 KG	36	static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
	37	{
	38	unsigned int i;
	39
	40	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
	41	if (wdt_timeout[i] >= secs)
	42	return i;
	43	}
	44
	45	return DA9063_TWDSCALE_MAX;
	46	}
	47
be9e9c2a MF	48	/*
	49	* Return 0 if watchdog is disabled, else non zero.
	50	*/
	51	static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
	52	{
	53	unsigned int val;
	54
	55	regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
	56
	57	return val & DA9063_TWDSCALE_MASK;
	58	}
	59
e46bb55d MF	60	static int da9063_wdt_disable_timer(struct da9063 *da9063)
	61	{
	62	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	63	DA9063_TWDSCALE_MASK,
	64	DA9063_TWDSCALE_DISABLE);
	65	}
	66
16a7eec2 MF	67	static int
16a7eec2 MF	68	da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout)
5e9c16e3	69	{
16a7eec2	70	unsigned int regval;
e46bb55d MF	71	int ret;
	72
	73	/*
	74	* The watchdog triggers a reboot if a timeout value is already
	75	* programmed because the timeout value combines two functions
	76	* in one: indicating the counter limit and starting the watchdog.
	77	* The watchdog must be disabled to be able to change the timeout
	78	* value if the watchdog is already running. Then we can set the
	79	* new timeout value which enables the watchdog again.
	80	*/
	81	ret = da9063_wdt_disable_timer(da9063);
	82	if (ret)
	83	return ret;
	84
	85	usleep_range(150, 300);
16a7eec2	86	regval = da9063_wdt_timeout_to_sel(timeout);
e46bb55d	87
5e9c16e3 KG	88	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	89	DA9063_TWDSCALE_MASK, regval);
	90	}
	91
	92	static int da9063_wdt_start(struct watchdog_device *wdd)
	93	{
a1f2a820	94	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	95	int ret;
5e9c16e3 KG	96
16a7eec2	97	ret = da9063_wdt_update_timeout(da9063, wdd->timeout);
5e9c16e3	98	if (ret)
a1f2a820	99	dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
5e9c16e3 KG	100	ret);
	101
	102	return ret;
	103	}
	104
	105	static int da9063_wdt_stop(struct watchdog_device *wdd)
	106	{
a1f2a820	107	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	108	int ret;
5e9c16e3 KG	109
e46bb55d	110	ret = da9063_wdt_disable_timer(da9063);
5e9c16e3	111	if (ret)
a1f2a820	112	dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
5e9c16e3 KG	113	ret);
	114
	115	return ret;
	116	}
	117
	118	static int da9063_wdt_ping(struct watchdog_device *wdd)
	119	{
a1f2a820	120	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	121	int ret;
5e9c16e3 KG	122
a1f2a820	123	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
5e9c16e3 KG	124	DA9063_WATCHDOG);
5e9c16e3 KG	125	if (ret)
a1f2a820	126	dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
5e9c16e3 KG	127	ret);
	128
	129	return ret;
	130	}
	131
	132	static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
	133	unsigned int timeout)
	134	{
a1f2a820	135	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
44ee54aa	136	int ret = 0;
5e9c16e3	137
44ee54aa MF	138	/*
	139	* There are two cases when a set_timeout() will be called:
	140	* 1. The watchdog is off and someone wants to set the timeout for the
	141	* further use.
	142	* 2. The watchdog is already running and a new timeout value should be
	143	* set.
	144	*
	145	* The watchdog can't store a timeout value not equal zero without
	146	* enabling the watchdog, so the timeout must be buffered by the driver.
	147	*/
	148	if (watchdog_active(wdd))
16a7eec2	149	ret = da9063_wdt_update_timeout(da9063, timeout);
44ee54aa	150
5e9c16e3	151	if (ret)
a1f2a820	152	dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
5e9c16e3 KG	153	ret);
5e9c16e3 KG	154	else
16a7eec2	155	wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)];
5e9c16e3 KG	156
	157	return ret;
	158	}
	159
4d8b229d GR	160	static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
4d8b229d GR	161	void *data)
396f163c	162	{
a1f2a820	163	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
396f163c GU	164	int ret;
396f163c GU	165
a1f2a820	166	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
396f163c GU	167	DA9063_SHUTDOWN);
396f163c GU	168	if (ret)
a1f2a820	169	dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
396f163c GU	170	ret);
396f163c GU	171
f79781ce	172	return ret;
396f163c GU	173	}
396f163c GU	174
5e9c16e3 KG	175	static const struct watchdog_info da9063_watchdog_info = {
	176	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	177	.identity = "DA9063 Watchdog",
	178	};
	179
	180	static const struct watchdog_ops da9063_watchdog_ops = {
	181	.owner = THIS_MODULE,
	182	.start = da9063_wdt_start,
	183	.stop = da9063_wdt_stop,
	184	.ping = da9063_wdt_ping,
	185	.set_timeout = da9063_wdt_set_timeout,
f79781ce	186	.restart = da9063_wdt_restart,
5e9c16e3 KG	187	};
	188
	189	static int da9063_wdt_probe(struct platform_device *pdev)
	190	{
5e9c16e3	191	struct da9063 *da9063;
a1f2a820	192	struct watchdog_device *wdd;
5e9c16e3 KG	193
	194	if (!pdev->dev.parent)
	195	return -EINVAL;
	196
	197	da9063 = dev_get_drvdata(pdev->dev.parent);
	198	if (!da9063)
	199	return -EINVAL;
	200
a1f2a820	201	wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
a1f2a820	202	if (!wdd)
5e9c16e3 KG	203	return -ENOMEM;
5e9c16e3 KG	204
a1f2a820	205	wdd->info = &da9063_watchdog_info;
	206	wdd->ops = &da9063_watchdog_ops;
	207	wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
	208	wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
	209	wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
	210	wdd->timeout = DA9063_WDG_TIMEOUT;
	211	wdd->parent = &pdev->dev;
5e9c16e3	212
a1f2a820	213	wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
5e9c16e3	214
a1f2a820	215	watchdog_set_restart_priority(wdd, 128);
f79781ce	216
a1f2a820	217	watchdog_set_drvdata(wdd, da9063);
5e9c16e3	218
be9e9c2a MF	219	/* Change the timeout to the default value if the watchdog is running */
be9e9c2a MF	220	if (da9063_wdt_is_running(da9063)) {
16a7eec2	221	da9063_wdt_update_timeout(da9063, DA9063_WDG_TIMEOUT);
be9e9c2a MF	222	set_bit(WDOG_HW_RUNNING, &wdd->status);
	223	}
	224
a1f2a820	225	return devm_watchdog_register_device(&pdev->dev, wdd);
5e9c16e3 KG	226	}
	227
	228	static struct platform_driver da9063_wdt_driver = {
	229	.probe = da9063_wdt_probe,
5e9c16e3 KG	230	.driver = {
	231	.name = DA9063_DRVNAME_WATCHDOG,
	232	},
	233	};
	234	module_platform_driver(da9063_wdt_driver);
	235
	236	MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
	237	MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
	238	MODULE_LICENSE("GPL");
	239	MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);