[mirror_ubuntu-jammy-kernel.git] / drivers / watchdog / da9052_wdt.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * System monitoring driver for DA9052 PMICs.
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: Anthony Olech <Anthony.Olech@diasemi.com>
 *
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/time.h>
#include <linux/watchdog.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>

#include <linux/mfd/da9052/reg.h>
#include <linux/mfd/da9052/da9052.h>

#define DA9052_DEF_TIMEOUT	4
#define DA9052_TWDMIN		256

struct da9052_wdt_data {
	struct watchdog_device wdt;
	struct da9052 *da9052;
	unsigned long jpast;
};

static const struct {
	u8 reg_val;
	int time;  /* Seconds */
} da9052_wdt_maps[] = {
	{ 1, 2 },
	{ 2, 4 },
	{ 3, 8 },
	{ 4, 16 },
	{ 5, 32 },
	{ 5, 33 },  /* Actual time  32.768s so included both 32s and 33s */
	{ 6, 65 },
	{ 6, 66 },  /* Actual time 65.536s so include both, 65s and 66s */
	{ 7, 131 },
};


static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
				  unsigned int timeout)
{
	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
	struct da9052 *da9052 = driver_data->da9052;
	int ret, i;

	/*
	 * Disable the Watchdog timer before setting
	 * new time out.
	 */
	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
				DA9052_CONTROLD_TWDSCALE, 0);
	if (ret < 0) {
		dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
			ret);
		return ret;
	}
	if (timeout) {
		/*
		 * To change the timeout, da9052 needs to
		 * be disabled for at least 150 us.
		 */
		udelay(150);

		/* Set the desired timeout */
		for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
			if (da9052_wdt_maps[i].time == timeout)
				break;

		if (i == ARRAY_SIZE(da9052_wdt_maps))
			ret = -EINVAL;
		else
			ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
						DA9052_CONTROLD_TWDSCALE,
						da9052_wdt_maps[i].reg_val);
		if (ret < 0) {
			dev_err(da9052->dev,
				"Failed to update timescale bit, %d\n", ret);
			return ret;
		}

		wdt_dev->timeout = timeout;
		driver_data->jpast = jiffies;
	}

	return 0;
}

static int da9052_wdt_start(struct watchdog_device *wdt_dev)
{
	return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
}

static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
{
	return da9052_wdt_set_timeout(wdt_dev, 0);
}

static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
{
	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
	struct da9052 *da9052 = driver_data->da9052;
	unsigned long msec, jnow = jiffies;
	int ret;

	/*
	 * We have a minimum time for watchdog window called TWDMIN. A write
	 * to the watchdog before this elapsed time should cause an error.
	 */
	msec = (jnow - driver_data->jpast) * 1000/HZ;
	if (msec < DA9052_TWDMIN)
		mdelay(msec);

	/* Reset the watchdog timer */
	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
				DA9052_CONTROLD_WATCHDOG, 1 << 7);
	if (ret < 0)
		return ret;

	/*
	 * FIXME: Reset the watchdog core, in general PMIC
	 * is supposed to do this
	 */
	return da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
				 DA9052_CONTROLD_WATCHDOG, 0 << 7);
}

static const struct watchdog_info da9052_wdt_info = {
	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
	.identity	= "DA9052 Watchdog",
};

static const struct watchdog_ops da9052_wdt_ops = {
	.owner = THIS_MODULE,
	.start = da9052_wdt_start,
	.stop = da9052_wdt_stop,
	.ping = da9052_wdt_ping,
	.set_timeout = da9052_wdt_set_timeout,
};


static int da9052_wdt_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct da9052 *da9052 = dev_get_drvdata(dev->parent);
	struct da9052_wdt_data *driver_data;
	struct watchdog_device *da9052_wdt;
	int ret;

	driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
	if (!driver_data)
		return -ENOMEM;
	driver_data->da9052 = da9052;

	da9052_wdt = &driver_data->wdt;

	da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
	da9052_wdt->info = &da9052_wdt_info;
	da9052_wdt->ops = &da9052_wdt_ops;
	da9052_wdt->parent = dev;
	watchdog_set_drvdata(da9052_wdt, driver_data);

	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
				DA9052_CONTROLD_TWDSCALE, 0);
	if (ret < 0) {
		dev_err(dev, "Failed to disable watchdog bits, %d\n", ret);
		return ret;
	}

	return devm_watchdog_register_device(dev, &driver_data->wdt);
}

static struct platform_driver da9052_wdt_driver = {
	.probe = da9052_wdt_probe,
	.driver = {
		.name	= "da9052-watchdog",
	},
};

module_platform_driver(da9052_wdt_driver);

MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
MODULE_DESCRIPTION("DA9052 SM Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-watchdog");
Commit	Line	Data
2e62c498	1	// SPDX-License-Identifier: GPL-2.0+
664a0d78 AJ	2	/*
	3	* System monitoring driver for DA9052 PMICs.
	4	*
	5	* Copyright(c) 2012 Dialog Semiconductor Ltd.
	6	*
	7	* Author: Anthony Olech <Anthony.Olech@diasemi.com>
	8	*
664a0d78 AJ	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/delay.h>
	13	#include <linux/uaccess.h>
	14	#include <linux/platform_device.h>
	15	#include <linux/time.h>
	16	#include <linux/watchdog.h>
	17	#include <linux/types.h>
	18	#include <linux/kernel.h>
	19	#include <linux/jiffies.h>
664a0d78 AJ	20
	21	#include <linux/mfd/da9052/reg.h>
	22	#include <linux/mfd/da9052/da9052.h>
	23
	24	#define DA9052_DEF_TIMEOUT 4
	25	#define DA9052_TWDMIN 256
	26
	27	struct da9052_wdt_data {
	28	struct watchdog_device wdt;
	29	struct da9052 *da9052;
664a0d78 AJ	30	unsigned long jpast;
	31	};
	32
	33	static const struct {
	34	u8 reg_val;
	35	int time; /* Seconds */
	36	} da9052_wdt_maps[] = {
	37	{ 1, 2 },
	38	{ 2, 4 },
	39	{ 3, 8 },
	40	{ 4, 16 },
	41	{ 5, 32 },
	42	{ 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
	43	{ 6, 65 },
	44	{ 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
	45	{ 7, 131 },
	46	};
	47
	48
664a0d78 AJ	49	static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
	50	unsigned int timeout)
	51	{
	52	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
	53	struct da9052 *da9052 = driver_data->da9052;
	54	int ret, i;
	55
	56	/*
	57	* Disable the Watchdog timer before setting
	58	* new time out.
	59	*/
	60	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	61	DA9052_CONTROLD_TWDSCALE, 0);
	62	if (ret < 0) {
	63	dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
	64	ret);
	65	return ret;
	66	}
	67	if (timeout) {
	68	/*
	69	* To change the timeout, da9052 needs to
	70	* be disabled for at least 150 us.
	71	*/
	72	udelay(150);
	73
	74	/* Set the desired timeout */
	75	for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
	76	if (da9052_wdt_maps[i].time == timeout)
	77	break;
	78
	79	if (i == ARRAY_SIZE(da9052_wdt_maps))
	80	ret = -EINVAL;
	81	else
	82	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	83	DA9052_CONTROLD_TWDSCALE,
	84	da9052_wdt_maps[i].reg_val);
	85	if (ret < 0) {
	86	dev_err(da9052->dev,
	87	"Failed to update timescale bit, %d\n", ret);
	88	return ret;
	89	}
	90
	91	wdt_dev->timeout = timeout;
	92	driver_data->jpast = jiffies;
	93	}
	94
	95	return 0;
	96	}
	97
664a0d78 AJ	98	static int da9052_wdt_start(struct watchdog_device *wdt_dev)
	99	{
	100	return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
	101	}
	102
	103	static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
	104	{
	105	return da9052_wdt_set_timeout(wdt_dev, 0);
	106	}
	107
	108	static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
	109	{
	110	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
	111	struct da9052 *da9052 = driver_data->da9052;
	112	unsigned long msec, jnow = jiffies;
	113	int ret;
	114
	115	/*
	116	* We have a minimum time for watchdog window called TWDMIN. A write
	117	* to the watchdog before this elapsed time should cause an error.
	118	*/
	119	msec = (jnow - driver_data->jpast) * 1000/HZ;
	120	if (msec < DA9052_TWDMIN)
	121	mdelay(msec);
	122
	123	/* Reset the watchdog timer */
	124	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	125	DA9052_CONTROLD_WATCHDOG, 1 << 7);
	126	if (ret < 0)
189c049a	127	return ret;
664a0d78 AJ	128
	129	/*
	130	* FIXME: Reset the watchdog core, in general PMIC
	131	* is supposed to do this
	132	*/
189c049a GR	133	return da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
189c049a GR	134	DA9052_CONTROLD_WATCHDOG, 0 << 7);
664a0d78 AJ	135	}
664a0d78 AJ	136
6c368932	137	static const struct watchdog_info da9052_wdt_info = {
664a0d78 AJ	138	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	139	.identity = "DA9052 Watchdog",
	140	};
	141
	142	static const struct watchdog_ops da9052_wdt_ops = {
	143	.owner = THIS_MODULE,
	144	.start = da9052_wdt_start,
	145	.stop = da9052_wdt_stop,
	146	.ping = da9052_wdt_ping,
	147	.set_timeout = da9052_wdt_set_timeout,
664a0d78 AJ	148	};
	149
	150
2d991a16	151	static int da9052_wdt_probe(struct platform_device *pdev)
664a0d78	152	{
f7e29623 GR	153	struct device *dev = &pdev->dev;
f7e29623 GR	154	struct da9052 *da9052 = dev_get_drvdata(dev->parent);
664a0d78 AJ	155	struct da9052_wdt_data *driver_data;
	156	struct watchdog_device *da9052_wdt;
	157	int ret;
	158
f7e29623	159	driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);
189c049a GR	160	if (!driver_data)
189c049a GR	161	return -ENOMEM;
664a0d78 AJ	162	driver_data->da9052 = da9052;
	163
	164	da9052_wdt = &driver_data->wdt;
	165
	166	da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
	167	da9052_wdt->info = &da9052_wdt_info;
	168	da9052_wdt->ops = &da9052_wdt_ops;
f7e29623	169	da9052_wdt->parent = dev;
664a0d78 AJ	170	watchdog_set_drvdata(da9052_wdt, driver_data);
664a0d78 AJ	171
664a0d78 AJ	172	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	173	DA9052_CONTROLD_TWDSCALE, 0);
	174	if (ret < 0) {
f7e29623	175	dev_err(dev, "Failed to disable watchdog bits, %d\n", ret);
189c049a	176	return ret;
664a0d78 AJ	177	}
664a0d78 AJ	178
60415f70	179	return devm_watchdog_register_device(dev, &driver_data->wdt);
664a0d78 AJ	180	}
664a0d78 AJ	181
664a0d78 AJ	182	static struct platform_driver da9052_wdt_driver = {
664a0d78 AJ	183	.probe = da9052_wdt_probe,
664a0d78 AJ	184	.driver = {
	185	.name = "da9052-watchdog",
	186	},
	187	};
	188
	189	module_platform_driver(da9052_wdt_driver);
	190
	191	MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
	192	MODULE_DESCRIPTION("DA9052 SM Device Driver");
	193	MODULE_LICENSE("GPL");
	194	MODULE_ALIAS("platform:da9052-watchdog");