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

/*
 * System monitoring driver for DA9052 PMICs.
 *
 * Copyright(c) 2012 Dialog Semiconductor Ltd.
 *
 * Author: Anthony Olech <Anthony.Olech@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/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)
		goto err_strobe;

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

static 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 da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
	struct da9052_wdt_data *driver_data;
	struct watchdog_device *da9052_wdt;
	int ret;

	driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
				   GFP_KERNEL);
	if (!driver_data) {
		ret = -ENOMEM;
		goto err;
	}
	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 = &pdev->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(&pdev->dev, "Failed to disable watchdog bits, %d\n",
			ret);
		goto err;
	}

	ret = watchdog_register_device(&driver_data->wdt);
	if (ret != 0) {
		dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
			ret);
		goto err;
	}

	platform_set_drvdata(pdev, driver_data);
err:
	return ret;
}

static int da9052_wdt_remove(struct platform_device *pdev)
{
	struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev);

	watchdog_unregister_device(&driver_data->wdt);

	return 0;
}

static struct platform_driver da9052_wdt_driver = {
	.probe = da9052_wdt_probe,
	.remove = da9052_wdt_remove,
	.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
664a0d78 AJ	1	/*
	2	* System monitoring driver for DA9052 PMICs.
	3	*
	4	* Copyright(c) 2012 Dialog Semiconductor Ltd.
	5	*
	6	* Author: Anthony Olech <Anthony.Olech@diasemi.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/delay.h>
	17	#include <linux/uaccess.h>
	18	#include <linux/platform_device.h>
	19	#include <linux/time.h>
	20	#include <linux/watchdog.h>
	21	#include <linux/types.h>
	22	#include <linux/kernel.h>
	23	#include <linux/jiffies.h>
664a0d78 AJ	24
	25	#include <linux/mfd/da9052/reg.h>
	26	#include <linux/mfd/da9052/da9052.h>
	27
	28	#define DA9052_DEF_TIMEOUT 4
	29	#define DA9052_TWDMIN 256
	30
	31	struct da9052_wdt_data {
	32	struct watchdog_device wdt;
	33	struct da9052 *da9052;
664a0d78 AJ	34	unsigned long jpast;
	35	};
	36
	37	static const struct {
	38	u8 reg_val;
	39	int time; /* Seconds */
	40	} da9052_wdt_maps[] = {
	41	{ 1, 2 },
	42	{ 2, 4 },
	43	{ 3, 8 },
	44	{ 4, 16 },
	45	{ 5, 32 },
	46	{ 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
	47	{ 6, 65 },
	48	{ 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
	49	{ 7, 131 },
	50	};
	51
	52
664a0d78 AJ	53	static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
	54	unsigned int timeout)
	55	{
	56	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
	57	struct da9052 *da9052 = driver_data->da9052;
	58	int ret, i;
	59
	60	/*
	61	* Disable the Watchdog timer before setting
	62	* new time out.
	63	*/
	64	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	65	DA9052_CONTROLD_TWDSCALE, 0);
	66	if (ret < 0) {
	67	dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
	68	ret);
	69	return ret;
	70	}
	71	if (timeout) {
	72	/*
	73	* To change the timeout, da9052 needs to
	74	* be disabled for at least 150 us.
	75	*/
	76	udelay(150);
	77
	78	/* Set the desired timeout */
	79	for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
	80	if (da9052_wdt_maps[i].time == timeout)
	81	break;
	82
	83	if (i == ARRAY_SIZE(da9052_wdt_maps))
	84	ret = -EINVAL;
	85	else
	86	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	87	DA9052_CONTROLD_TWDSCALE,
	88	da9052_wdt_maps[i].reg_val);
	89	if (ret < 0) {
	90	dev_err(da9052->dev,
	91	"Failed to update timescale bit, %d\n", ret);
	92	return ret;
	93	}
	94
	95	wdt_dev->timeout = timeout;
	96	driver_data->jpast = jiffies;
	97	}
	98
	99	return 0;
	100	}
	101
664a0d78 AJ	102	static int da9052_wdt_start(struct watchdog_device *wdt_dev)
	103	{
	104	return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
	105	}
	106
	107	static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
	108	{
	109	return da9052_wdt_set_timeout(wdt_dev, 0);
	110	}
	111
	112	static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
	113	{
	114	struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
	115	struct da9052 *da9052 = driver_data->da9052;
	116	unsigned long msec, jnow = jiffies;
	117	int ret;
	118
	119	/*
	120	* We have a minimum time for watchdog window called TWDMIN. A write
	121	* to the watchdog before this elapsed time should cause an error.
	122	*/
	123	msec = (jnow - driver_data->jpast) * 1000/HZ;
	124	if (msec < DA9052_TWDMIN)
	125	mdelay(msec);
	126
	127	/* Reset the watchdog timer */
	128	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	129	DA9052_CONTROLD_WATCHDOG, 1 << 7);
	130	if (ret < 0)
	131	goto err_strobe;
	132
	133	/*
	134	* FIXME: Reset the watchdog core, in general PMIC
	135	* is supposed to do this
	136	*/
	137	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	138	DA9052_CONTROLD_WATCHDOG, 0 << 7);
	139	err_strobe:
	140	return ret;
	141	}
	142
	143	static struct watchdog_info da9052_wdt_info = {
	144	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	145	.identity = "DA9052 Watchdog",
	146	};
	147
	148	static const struct watchdog_ops da9052_wdt_ops = {
	149	.owner = THIS_MODULE,
	150	.start = da9052_wdt_start,
	151	.stop = da9052_wdt_stop,
	152	.ping = da9052_wdt_ping,
	153	.set_timeout = da9052_wdt_set_timeout,
664a0d78 AJ	154	};
	155
	156
2d991a16	157	static int da9052_wdt_probe(struct platform_device *pdev)
664a0d78 AJ	158	{
	159	struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
	160	struct da9052_wdt_data *driver_data;
	161	struct watchdog_device *da9052_wdt;
	162	int ret;
	163
	164	driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
	165	GFP_KERNEL);
	166	if (!driver_data) {
664a0d78 AJ	167	ret = -ENOMEM;
	168	goto err;
	169	}
	170	driver_data->da9052 = da9052;
	171
	172	da9052_wdt = &driver_data->wdt;
	173
	174	da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
	175	da9052_wdt->info = &da9052_wdt_info;
	176	da9052_wdt->ops = &da9052_wdt_ops;
6551881c	177	da9052_wdt->parent = &pdev->dev;
664a0d78 AJ	178	watchdog_set_drvdata(da9052_wdt, driver_data);
664a0d78 AJ	179
664a0d78 AJ	180	ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
	181	DA9052_CONTROLD_TWDSCALE, 0);
	182	if (ret < 0) {
	183	dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n",
	184	ret);
	185	goto err;
	186	}
	187
	188	ret = watchdog_register_device(&driver_data->wdt);
	189	if (ret != 0) {
	190	dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
	191	ret);
	192	goto err;
	193	}
	194
552a9641	195	platform_set_drvdata(pdev, driver_data);
664a0d78 AJ	196	err:
	197	return ret;
	198	}
	199
4b12b896	200	static int da9052_wdt_remove(struct platform_device *pdev)
664a0d78	201	{
552a9641	202	struct da9052_wdt_data *driver_data = platform_get_drvdata(pdev);
664a0d78 AJ	203
664a0d78 AJ	204	watchdog_unregister_device(&driver_data->wdt);
664a0d78 AJ	205
	206	return 0;
	207	}
	208
	209	static struct platform_driver da9052_wdt_driver = {
	210	.probe = da9052_wdt_probe,
82268714	211	.remove = da9052_wdt_remove,
664a0d78 AJ	212	.driver = {
	213	.name = "da9052-watchdog",
	214	},
	215	};
	216
	217	module_platform_driver(da9052_wdt_driver);
	218
	219	MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
	220	MODULE_DESCRIPTION("DA9052 SM Device Driver");
	221	MODULE_LICENSE("GPL");
	222	MODULE_ALIAS("platform:da9052-watchdog");