[mirror_ubuntu-hirsute-kernel.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 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);

	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);
	unsigned int selector;
	int ret;

	selector = da9063_wdt_timeout_to_sel(wdd->timeout);
	ret = da9063_wdt_update_timeout(da9063, selector);
	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);
	unsigned int selector;
	int ret = 0;

	selector = da9063_wdt_timeout_to_sel(timeout);

	/*
	 * 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, selector);

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

	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)) {
		unsigned int timeout;

		timeout = da9063_wdt_timeout_to_sel(DA9063_WDG_TIMEOUT);
		da9063_wdt_update_timeout(da9063, 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
6f4cedb7	67	static int da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int regval)
5e9c16e3	68	{
e46bb55d MF	69	int ret;
	70
	71	/*
	72	* The watchdog triggers a reboot if a timeout value is already
	73	* programmed because the timeout value combines two functions
	74	* in one: indicating the counter limit and starting the watchdog.
	75	* The watchdog must be disabled to be able to change the timeout
	76	* value if the watchdog is already running. Then we can set the
	77	* new timeout value which enables the watchdog again.
	78	*/
	79	ret = da9063_wdt_disable_timer(da9063);
	80	if (ret)
	81	return ret;
	82
	83	usleep_range(150, 300);
	84
5e9c16e3 KG	85	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	86	DA9063_TWDSCALE_MASK, regval);
	87	}
	88
	89	static int da9063_wdt_start(struct watchdog_device *wdd)
	90	{
a1f2a820	91	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	92	unsigned int selector;
	93	int ret;
	94
a1f2a820	95	selector = da9063_wdt_timeout_to_sel(wdd->timeout);
6f4cedb7	96	ret = da9063_wdt_update_timeout(da9063, selector);
5e9c16e3	97	if (ret)
a1f2a820	98	dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
5e9c16e3 KG	99	ret);
	100
	101	return ret;
	102	}
	103
	104	static int da9063_wdt_stop(struct watchdog_device *wdd)
	105	{
a1f2a820	106	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	107	int ret;
5e9c16e3 KG	108
e46bb55d	109	ret = da9063_wdt_disable_timer(da9063);
5e9c16e3	110	if (ret)
a1f2a820	111	dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
5e9c16e3 KG	112	ret);
	113
	114	return ret;
	115	}
	116
	117	static int da9063_wdt_ping(struct watchdog_device *wdd)
	118	{
a1f2a820	119	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	120	int ret;
5e9c16e3 KG	121
a1f2a820	122	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
5e9c16e3 KG	123	DA9063_WATCHDOG);
5e9c16e3 KG	124	if (ret)
a1f2a820	125	dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
5e9c16e3 KG	126	ret);
	127
	128	return ret;
	129	}
	130
	131	static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
	132	unsigned int timeout)
	133	{
a1f2a820	134	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3	135	unsigned int selector;
44ee54aa	136	int ret = 0;
5e9c16e3 KG	137
5e9c16e3 KG	138	selector = da9063_wdt_timeout_to_sel(timeout);
44ee54aa MF	139
	140	/*
	141	* There are two cases when a set_timeout() will be called:
	142	* 1. The watchdog is off and someone wants to set the timeout for the
	143	* further use.
	144	* 2. The watchdog is already running and a new timeout value should be
	145	* set.
	146	*
	147	* The watchdog can't store a timeout value not equal zero without
	148	* enabling the watchdog, so the timeout must be buffered by the driver.
	149	*/
	150	if (watchdog_active(wdd))
6f4cedb7	151	ret = da9063_wdt_update_timeout(da9063, selector);
44ee54aa	152
5e9c16e3	153	if (ret)
a1f2a820	154	dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
5e9c16e3 KG	155	ret);
	156	else
	157	wdd->timeout = wdt_timeout[selector];
	158
	159	return ret;
	160	}
	161
4d8b229d GR	162	static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
4d8b229d GR	163	void *data)
396f163c	164	{
a1f2a820	165	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
396f163c GU	166	int ret;
396f163c GU	167
a1f2a820	168	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
396f163c GU	169	DA9063_SHUTDOWN);
396f163c GU	170	if (ret)
a1f2a820	171	dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
396f163c GU	172	ret);
396f163c GU	173
f79781ce	174	return ret;
396f163c GU	175	}
396f163c GU	176
5e9c16e3 KG	177	static const struct watchdog_info da9063_watchdog_info = {
	178	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	179	.identity = "DA9063 Watchdog",
	180	};
	181
	182	static const struct watchdog_ops da9063_watchdog_ops = {
	183	.owner = THIS_MODULE,
	184	.start = da9063_wdt_start,
	185	.stop = da9063_wdt_stop,
	186	.ping = da9063_wdt_ping,
	187	.set_timeout = da9063_wdt_set_timeout,
f79781ce	188	.restart = da9063_wdt_restart,
5e9c16e3 KG	189	};
	190
	191	static int da9063_wdt_probe(struct platform_device *pdev)
	192	{
5e9c16e3	193	struct da9063 *da9063;
a1f2a820	194	struct watchdog_device *wdd;
5e9c16e3 KG	195
	196	if (!pdev->dev.parent)
	197	return -EINVAL;
	198
	199	da9063 = dev_get_drvdata(pdev->dev.parent);
	200	if (!da9063)
	201	return -EINVAL;
	202
a1f2a820	203	wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
a1f2a820	204	if (!wdd)
5e9c16e3 KG	205	return -ENOMEM;
5e9c16e3 KG	206
a1f2a820	207	wdd->info = &da9063_watchdog_info;
	208	wdd->ops = &da9063_watchdog_ops;
	209	wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
	210	wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
	211	wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
	212	wdd->timeout = DA9063_WDG_TIMEOUT;
	213	wdd->parent = &pdev->dev;
5e9c16e3	214
a1f2a820	215	wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
5e9c16e3	216
a1f2a820	217	watchdog_set_restart_priority(wdd, 128);
f79781ce	218
a1f2a820	219	watchdog_set_drvdata(wdd, da9063);
5e9c16e3	220
be9e9c2a MF	221	/* Change the timeout to the default value if the watchdog is running */
	222	if (da9063_wdt_is_running(da9063)) {
	223	unsigned int timeout;
	224
	225	timeout = da9063_wdt_timeout_to_sel(DA9063_WDG_TIMEOUT);
6f4cedb7	226	da9063_wdt_update_timeout(da9063, timeout);
be9e9c2a MF	227	set_bit(WDOG_HW_RUNNING, &wdd->status);
	228	}
	229
a1f2a820	230	return devm_watchdog_register_device(&pdev->dev, wdd);
5e9c16e3 KG	231	}
	232
	233	static struct platform_driver da9063_wdt_driver = {
	234	.probe = da9063_wdt_probe,
5e9c16e3 KG	235	.driver = {
	236	.name = DA9063_DRVNAME_WATCHDOG,
	237	},
	238	};
	239	module_platform_driver(da9063_wdt_driver);
	240
	241	MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
	242	MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
	243	MODULE_LICENSE("GPL");
	244	MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);