[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;
}

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_set_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_set_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_set_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);

	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
e46bb55d MF	48	static int da9063_wdt_disable_timer(struct da9063 *da9063)
	49	{
	50	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	51	DA9063_TWDSCALE_MASK,
	52	DA9063_TWDSCALE_DISABLE);
	53	}
	54
5e9c16e3 KG	55	static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
5e9c16e3 KG	56	{
e46bb55d MF	57	int ret;
	58
	59	/*
	60	* The watchdog triggers a reboot if a timeout value is already
	61	* programmed because the timeout value combines two functions
	62	* in one: indicating the counter limit and starting the watchdog.
	63	* The watchdog must be disabled to be able to change the timeout
	64	* value if the watchdog is already running. Then we can set the
	65	* new timeout value which enables the watchdog again.
	66	*/
	67	ret = da9063_wdt_disable_timer(da9063);
	68	if (ret)
	69	return ret;
	70
	71	usleep_range(150, 300);
	72
5e9c16e3 KG	73	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	74	DA9063_TWDSCALE_MASK, regval);
	75	}
	76
	77	static int da9063_wdt_start(struct watchdog_device *wdd)
	78	{
a1f2a820	79	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	80	unsigned int selector;
	81	int ret;
	82
a1f2a820	83	selector = da9063_wdt_timeout_to_sel(wdd->timeout);
a1f2a820	84	ret = _da9063_wdt_set_timeout(da9063, selector);
5e9c16e3	85	if (ret)
a1f2a820	86	dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
5e9c16e3 KG	87	ret);
	88
	89	return ret;
	90	}
	91
	92	static int da9063_wdt_stop(struct watchdog_device *wdd)
	93	{
a1f2a820	94	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	95	int ret;
5e9c16e3 KG	96
e46bb55d	97	ret = da9063_wdt_disable_timer(da9063);
5e9c16e3	98	if (ret)
a1f2a820	99	dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
5e9c16e3 KG	100	ret);
	101
	102	return ret;
	103	}
	104
	105	static int da9063_wdt_ping(struct watchdog_device *wdd)
	106	{
a1f2a820	107	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	108	int ret;
5e9c16e3 KG	109
a1f2a820	110	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
5e9c16e3 KG	111	DA9063_WATCHDOG);
5e9c16e3 KG	112	if (ret)
a1f2a820	113	dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
5e9c16e3 KG	114	ret);
	115
	116	return ret;
	117	}
	118
	119	static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
	120	unsigned int timeout)
	121	{
a1f2a820	122	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3	123	unsigned int selector;
44ee54aa	124	int ret = 0;
5e9c16e3 KG	125
5e9c16e3 KG	126	selector = da9063_wdt_timeout_to_sel(timeout);
44ee54aa MF	127
	128	/*
	129	* There are two cases when a set_timeout() will be called:
	130	* 1. The watchdog is off and someone wants to set the timeout for the
	131	* further use.
	132	* 2. The watchdog is already running and a new timeout value should be
	133	* set.
	134	*
	135	* The watchdog can't store a timeout value not equal zero without
	136	* enabling the watchdog, so the timeout must be buffered by the driver.
	137	*/
	138	if (watchdog_active(wdd))
	139	ret = _da9063_wdt_set_timeout(da9063, selector);
	140
5e9c16e3	141	if (ret)
a1f2a820	142	dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
5e9c16e3 KG	143	ret);
	144	else
	145	wdd->timeout = wdt_timeout[selector];
	146
	147	return ret;
	148	}
	149
4d8b229d GR	150	static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
4d8b229d GR	151	void *data)
396f163c	152	{
a1f2a820	153	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
396f163c GU	154	int ret;
396f163c GU	155
a1f2a820	156	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
396f163c GU	157	DA9063_SHUTDOWN);
396f163c GU	158	if (ret)
a1f2a820	159	dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
396f163c GU	160	ret);
396f163c GU	161
f79781ce	162	return ret;
396f163c GU	163	}
396f163c GU	164
5e9c16e3 KG	165	static const struct watchdog_info da9063_watchdog_info = {
	166	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	167	.identity = "DA9063 Watchdog",
	168	};
	169
	170	static const struct watchdog_ops da9063_watchdog_ops = {
	171	.owner = THIS_MODULE,
	172	.start = da9063_wdt_start,
	173	.stop = da9063_wdt_stop,
	174	.ping = da9063_wdt_ping,
	175	.set_timeout = da9063_wdt_set_timeout,
f79781ce	176	.restart = da9063_wdt_restart,
5e9c16e3 KG	177	};
	178
	179	static int da9063_wdt_probe(struct platform_device *pdev)
	180	{
5e9c16e3	181	struct da9063 *da9063;
a1f2a820	182	struct watchdog_device *wdd;
5e9c16e3 KG	183
	184	if (!pdev->dev.parent)
	185	return -EINVAL;
	186
	187	da9063 = dev_get_drvdata(pdev->dev.parent);
	188	if (!da9063)
	189	return -EINVAL;
	190
a1f2a820	191	wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
a1f2a820	192	if (!wdd)
5e9c16e3 KG	193	return -ENOMEM;
5e9c16e3 KG	194
a1f2a820	195	wdd->info = &da9063_watchdog_info;
	196	wdd->ops = &da9063_watchdog_ops;
	197	wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
	198	wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
	199	wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
	200	wdd->timeout = DA9063_WDG_TIMEOUT;
	201	wdd->parent = &pdev->dev;
5e9c16e3	202
a1f2a820	203	wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
5e9c16e3	204
a1f2a820	205	watchdog_set_restart_priority(wdd, 128);
f79781ce	206
a1f2a820	207	watchdog_set_drvdata(wdd, da9063);
5e9c16e3	208
a1f2a820	209	return devm_watchdog_register_device(&pdev->dev, wdd);
5e9c16e3 KG	210	}
	211
	212	static struct platform_driver da9063_wdt_driver = {
	213	.probe = da9063_wdt_probe,
5e9c16e3 KG	214	.driver = {
	215	.name = DA9063_DRVNAME_WATCHDOG,
	216	},
	217	};
	218	module_platform_driver(da9063_wdt_driver);
	219
	220	MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
	221	MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
	222	MODULE_LICENSE("GPL");
	223	MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);