[mirror_ubuntu-bionic-kernel.git] / drivers / watchdog / da9063_wdt.c

/*
 * Watchdog driver for DA9063 PMICs.
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.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;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#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_set_timeout(struct da9063 *da9063, unsigned int regval)
{
	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 = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
				 DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
	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
5e9c16e3 KG	1	/*
	2	* Watchdog driver for DA9063 PMICs.
	3	*
	4	* Copyright(c) 2012 Dialog Semiconductor Ltd.
	5	*
	6	* Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/watchdog.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/uaccess.h>
	19	#include <linux/slab.h>
	20	#include <linux/delay.h>
	21	#include <linux/mfd/da9063/registers.h>
	22	#include <linux/mfd/da9063/core.h>
	23	#include <linux/regmap.h>
	24
	25	/*
	26	* Watchdog selector to timeout in seconds.
	27	* 0: WDT disabled;
	28	* others: timeout = 2048 ms * 2^(TWDSCALE-1).
	29	*/
	30	static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
	31	#define DA9063_TWDSCALE_DISABLE 0
	32	#define DA9063_TWDSCALE_MIN 1
	33	#define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1)
	34	#define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN]
	35	#define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX]
	36	#define DA9063_WDG_TIMEOUT wdt_timeout[3]
a74cab40	37	#define DA9063_RESET_PROTECTION_MS 256
5e9c16e3	38
5e9c16e3 KG	39	static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
	40	{
	41	unsigned int i;
	42
	43	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
	44	if (wdt_timeout[i] >= secs)
	45	return i;
	46	}
	47
	48	return DA9063_TWDSCALE_MAX;
	49	}
	50
	51	static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
	52	{
	53	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	54	DA9063_TWDSCALE_MASK, regval);
	55	}
	56
	57	static int da9063_wdt_start(struct watchdog_device *wdd)
	58	{
a1f2a820	59	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	60	unsigned int selector;
	61	int ret;
	62
a1f2a820	63	selector = da9063_wdt_timeout_to_sel(wdd->timeout);
a1f2a820	64	ret = _da9063_wdt_set_timeout(da9063, selector);
5e9c16e3	65	if (ret)
a1f2a820	66	dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
5e9c16e3 KG	67	ret);
	68
	69	return ret;
	70	}
	71
	72	static int da9063_wdt_stop(struct watchdog_device *wdd)
	73	{
a1f2a820	74	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	75	int ret;
5e9c16e3 KG	76
a1f2a820	77	ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
5e9c16e3 KG	78	DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
5e9c16e3 KG	79	if (ret)
a1f2a820	80	dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
5e9c16e3 KG	81	ret);
	82
	83	return ret;
	84	}
	85
	86	static int da9063_wdt_ping(struct watchdog_device *wdd)
	87	{
a1f2a820	88	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3 KG	89	int ret;
5e9c16e3 KG	90
a1f2a820	91	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
5e9c16e3 KG	92	DA9063_WATCHDOG);
5e9c16e3 KG	93	if (ret)
a1f2a820	94	dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
5e9c16e3 KG	95	ret);
	96
	97	return ret;
	98	}
	99
	100	static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
	101	unsigned int timeout)
	102	{
a1f2a820	103	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
5e9c16e3	104	unsigned int selector;
2914be71	105	int ret = 0;
5e9c16e3 KG	106
5e9c16e3 KG	107	selector = da9063_wdt_timeout_to_sel(timeout);
2914be71 MF	108
	109	/*
	110	* There are two cases when a set_timeout() will be called:
	111	* 1. The watchdog is off and someone wants to set the timeout for the
	112	* further use.
	113	* 2. The watchdog is already running and a new timeout value should be
	114	* set.
	115	*
	116	* The watchdog can't store a timeout value not equal zero without
	117	* enabling the watchdog, so the timeout must be buffered by the driver.
	118	*/
	119	if (watchdog_active(wdd))
	120	ret = _da9063_wdt_set_timeout(da9063, selector);
	121
5e9c16e3	122	if (ret)
a1f2a820	123	dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
5e9c16e3 KG	124	ret);
	125	else
	126	wdd->timeout = wdt_timeout[selector];
	127
	128	return ret;
	129	}
	130
4d8b229d GR	131	static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
4d8b229d GR	132	void *data)
396f163c	133	{
a1f2a820	134	struct da9063 *da9063 = watchdog_get_drvdata(wdd);
396f163c GU	135	int ret;
396f163c GU	136
a1f2a820	137	ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
396f163c GU	138	DA9063_SHUTDOWN);
396f163c GU	139	if (ret)
a1f2a820	140	dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
396f163c GU	141	ret);
396f163c GU	142
f79781ce	143	return ret;
396f163c GU	144	}
396f163c GU	145
5e9c16e3 KG	146	static const struct watchdog_info da9063_watchdog_info = {
	147	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	148	.identity = "DA9063 Watchdog",
	149	};
	150
	151	static const struct watchdog_ops da9063_watchdog_ops = {
	152	.owner = THIS_MODULE,
	153	.start = da9063_wdt_start,
	154	.stop = da9063_wdt_stop,
	155	.ping = da9063_wdt_ping,
	156	.set_timeout = da9063_wdt_set_timeout,
f79781ce	157	.restart = da9063_wdt_restart,
5e9c16e3 KG	158	};
	159
	160	static int da9063_wdt_probe(struct platform_device *pdev)
	161	{
5e9c16e3	162	struct da9063 *da9063;
a1f2a820	163	struct watchdog_device *wdd;
5e9c16e3 KG	164
	165	if (!pdev->dev.parent)
	166	return -EINVAL;
	167
	168	da9063 = dev_get_drvdata(pdev->dev.parent);
	169	if (!da9063)
	170	return -EINVAL;
	171
a1f2a820	172	wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
a1f2a820	173	if (!wdd)
5e9c16e3 KG	174	return -ENOMEM;
5e9c16e3 KG	175
a1f2a820	176	wdd->info = &da9063_watchdog_info;
	177	wdd->ops = &da9063_watchdog_ops;
	178	wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
	179	wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
	180	wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
	181	wdd->timeout = DA9063_WDG_TIMEOUT;
	182	wdd->parent = &pdev->dev;
5e9c16e3	183
a1f2a820	184	wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
5e9c16e3	185
a1f2a820	186	watchdog_set_restart_priority(wdd, 128);
f79781ce	187
a1f2a820	188	watchdog_set_drvdata(wdd, da9063);
5e9c16e3	189
a1f2a820	190	return devm_watchdog_register_device(&pdev->dev, wdd);
5e9c16e3 KG	191	}
	192
	193	static struct platform_driver da9063_wdt_driver = {
	194	.probe = da9063_wdt_probe,
5e9c16e3 KG	195	.driver = {
	196	.name = DA9063_DRVNAME_WATCHDOG,
	197	},
	198	};
	199	module_platform_driver(da9063_wdt_driver);
	200
	201	MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
	202	MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
	203	MODULE_LICENSE("GPL");
	204	MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);