[linux-2.6-block.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]

struct da9063_watchdog {
	struct da9063 *da9063;
	struct watchdog_device wdtdev;
};

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_watchdog *wdt = watchdog_get_drvdata(wdd);
	unsigned int selector;
	int ret;

	selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout);
	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
	if (ret)
		dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
			ret);

	return ret;
}

static int da9063_wdt_stop(struct watchdog_device *wdd)
{
	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D,
				 DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
	if (ret)
		dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
			  ret);

	return ret;
}

static int da9063_wdt_ping(struct watchdog_device *wdd)
{
	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	int ret;

	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
			   DA9063_WATCHDOG);
	if (ret)
		dev_alert(wdt->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_watchdog *wdt = watchdog_get_drvdata(wdd);
	unsigned int selector;
	int ret;

	selector = da9063_wdt_timeout_to_sel(timeout);
	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
	if (ret)
		dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
			ret);
	else
		wdd->timeout = wdt_timeout[selector];

	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,
};

static int da9063_wdt_probe(struct platform_device *pdev)
{
	int ret;
	struct da9063 *da9063;
	struct da9063_watchdog *wdt;

	if (!pdev->dev.parent)
		return -EINVAL;

	da9063 = dev_get_drvdata(pdev->dev.parent);
	if (!da9063)
		return -EINVAL;

	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
	if (!wdt)
		return -ENOMEM;

	wdt->da9063 = da9063;

	wdt->wdtdev.info = &da9063_watchdog_info;
	wdt->wdtdev.ops = &da9063_watchdog_ops;
	wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT;
	wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT;
	wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT;

	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;

	watchdog_set_drvdata(&wdt->wdtdev, wdt);
	dev_set_drvdata(&pdev->dev, wdt);

	ret = watchdog_register_device(&wdt->wdtdev);

	return ret;
}

static int da9063_wdt_remove(struct platform_device *pdev)
{
	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);

	watchdog_unregister_device(&wdt->wdtdev);

	return 0;
}

static struct platform_driver da9063_wdt_driver = {
	.probe = da9063_wdt_probe,
	.remove = da9063_wdt_remove,
	.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]
	37
	38	struct da9063_watchdog {
	39	struct da9063 *da9063;
	40	struct watchdog_device wdtdev;
	41	};
	42
	43	static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
	44	{
	45	unsigned int i;
	46
	47	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
	48	if (wdt_timeout[i] >= secs)
	49	return i;
	50	}
	51
	52	return DA9063_TWDSCALE_MAX;
	53	}
	54
	55	static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
	56	{
	57	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
	58	DA9063_TWDSCALE_MASK, regval);
	59	}
	60
	61	static int da9063_wdt_start(struct watchdog_device *wdd)
	62	{
	63	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
	64	unsigned int selector;
65	int ret;
66
67	selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout);
68	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
69	if (ret)
70	dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
71	ret);
72
73	return ret;
74	}
75
76	static int da9063_wdt_stop(struct watchdog_device *wdd)
77	{
78	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
79	int ret;
80
81	ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D,
82	DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
83	if (ret)
84	dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
85	ret);
86
87	return ret;
88	}
89
90	static int da9063_wdt_ping(struct watchdog_device *wdd)
91	{
92	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
93	int ret;
94
95	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
96	DA9063_WATCHDOG);
97	if (ret)
98	dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n",
99	ret);
100
101	return ret;
102	}
103
104	static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
105	unsigned int timeout)
106	{
107	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
108	unsigned int selector;
109	int ret;
110
111	selector = da9063_wdt_timeout_to_sel(timeout);
112	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
113	if (ret)
114	dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
115	ret);
116	else
117	wdd->timeout = wdt_timeout[selector];
118
119	return ret;
120	}
121
122	static const struct watchdog_info da9063_watchdog_info = {
123	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
124	.identity = "DA9063 Watchdog",
125	};
126
127	static const struct watchdog_ops da9063_watchdog_ops = {
128	.owner = THIS_MODULE,
129	.start = da9063_wdt_start,
130	.stop = da9063_wdt_stop,
131	.ping = da9063_wdt_ping,
132	.set_timeout = da9063_wdt_set_timeout,
133	};
134
135	static int da9063_wdt_probe(struct platform_device *pdev)
136	{
137	int ret;
138	struct da9063 *da9063;
139	struct da9063_watchdog *wdt;
140
141	if (!pdev->dev.parent)
142	return -EINVAL;
143
144	da9063 = dev_get_drvdata(pdev->dev.parent);
145	if (!da9063)
146	return -EINVAL;
147
148	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
149	if (!wdt)
150	return -ENOMEM;
151
152	wdt->da9063 = da9063;
153
154	wdt->wdtdev.info = &da9063_watchdog_info;
155	wdt->wdtdev.ops = &da9063_watchdog_ops;
156	wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT;
157	wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT;
158	wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT;
159
160	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
161
162	watchdog_set_drvdata(&wdt->wdtdev, wdt);
163	dev_set_drvdata(&pdev->dev, wdt);
164
165	ret = watchdog_register_device(&wdt->wdtdev);
166
167	return ret;
168	}
169
170	static int da9063_wdt_remove(struct platform_device *pdev)
171	{
172	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);
173
174	watchdog_unregister_device(&wdt->wdtdev);
175
176	return 0;
177	}
178
179	static struct platform_driver da9063_wdt_driver = {
180	.probe = da9063_wdt_probe,
181	.remove = da9063_wdt_remove,
182	.driver = {
183	.name = DA9063_DRVNAME_WATCHDOG,
184	},
185	};
186	module_platform_driver(da9063_wdt_driver);
187
188	MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
189	MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
190	MODULE_LICENSE("GPL");
191	MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);