[net-next-2.6.git] / drivers / watchdog / wm831x_wdt.c

/*
 * Watchdog driver for the wm831x PMICs
 *
 * Copyright (C) 2009 Wolfson Microelectronics
 *
 * 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
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/gpio.h>

#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/watchdog.h>

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
		 "Watchdog cannot be stopped once started (default="
		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static unsigned long wm831x_wdt_users;
static struct miscdevice wm831x_wdt_miscdev;
static int wm831x_wdt_expect_close;
static DEFINE_MUTEX(wdt_mutex);
static struct wm831x *wm831x;
static unsigned int update_gpio;
static unsigned int update_state;

/* We can't use the sub-second values here but they're included
 * for completeness.  */
static struct {
	int time;  /* Seconds */
	u16 val;   /* WDOG_TO value */
} wm831x_wdt_cfgs[] = {
	{  1, 2 },
	{  2, 3 },
	{  4, 4 },
	{  8, 5 },
	{ 16, 6 },
	{ 32, 7 },
	{ 33, 7 },  /* Actually 32.768s so include both, others round down */
};

static int wm831x_wdt_set_timeout(struct wm831x *wm831x, u16 value)
{
	int ret;

	mutex_lock(&wdt_mutex);

	ret = wm831x_reg_unlock(wm831x);
	if (ret == 0) {
		ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
				      WM831X_WDOG_TO_MASK, value);
		wm831x_reg_lock(wm831x);
	} else {
		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
			ret);
	}

	mutex_unlock(&wdt_mutex);

	return ret;
}

static int wm831x_wdt_start(struct wm831x *wm831x)
{
	int ret;

	mutex_lock(&wdt_mutex);

	ret = wm831x_reg_unlock(wm831x);
	if (ret == 0) {
		ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
				      WM831X_WDOG_ENA, WM831X_WDOG_ENA);
		wm831x_reg_lock(wm831x);
	} else {
		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
			ret);
	}

	mutex_unlock(&wdt_mutex);

	return ret;
}

static int wm831x_wdt_stop(struct wm831x *wm831x)
{
	int ret;

	mutex_lock(&wdt_mutex);

	ret = wm831x_reg_unlock(wm831x);
	if (ret == 0) {
		ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
				      WM831X_WDOG_ENA, 0);
		wm831x_reg_lock(wm831x);
	} else {
		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
			ret);
	}

	mutex_unlock(&wdt_mutex);

	return ret;
}

static int wm831x_wdt_kick(struct wm831x *wm831x)
{
	int ret;
	u16 reg;

	mutex_lock(&wdt_mutex);

	if (update_gpio) {
		gpio_set_value_cansleep(update_gpio, update_state);
		update_state = !update_state;
		ret = 0;
		goto out;
	}


	reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);

	if (!(reg & WM831X_WDOG_RST_SRC)) {
		dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
		ret = -EINVAL;
		goto out;
	}

	reg |= WM831X_WDOG_RESET;

	ret = wm831x_reg_unlock(wm831x);
	if (ret == 0) {
		ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
		wm831x_reg_lock(wm831x);
	} else {
		dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
			ret);
	}

out:
	mutex_unlock(&wdt_mutex);

	return ret;
}

static int wm831x_wdt_open(struct inode *inode, struct file *file)
{
	int ret;

	if (!wm831x)
		return -ENODEV;

	if (test_and_set_bit(0, &wm831x_wdt_users))
		return -EBUSY;

	ret = wm831x_wdt_start(wm831x);
	if (ret != 0)
		return ret;

	return nonseekable_open(inode, file);
}

static int wm831x_wdt_release(struct inode *inode, struct file *file)
{
	if (wm831x_wdt_expect_close)
		wm831x_wdt_stop(wm831x);
	else {
		dev_warn(wm831x->dev, "Watchdog device closed uncleanly\n");
		wm831x_wdt_kick(wm831x);
	}

	clear_bit(0, &wm831x_wdt_users);

	return 0;
}

static ssize_t wm831x_wdt_write(struct file *file,
				const char __user *data, size_t count,
				loff_t *ppos)
{
	size_t i;

	if (count) {
		wm831x_wdt_kick(wm831x);

		if (!nowayout) {
			/* In case it was set long ago */
			wm831x_wdt_expect_close = 0;

			/* scan to see whether or not we got the magic
			   character */
			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					wm831x_wdt_expect_close = 42;
			}
		}
	}
	return count;
}

static const struct watchdog_info ident = {
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
	.identity = "WM831x Watchdog",
};

static long wm831x_wdt_ioctl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	int ret = -ENOTTY, time, i;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	u16 reg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		ret = put_user(0, p);
		break;

	case WDIOC_SETOPTIONS:
	{
		int options;

		if (get_user(options, p))
			return -EFAULT;

		ret = -EINVAL;

		/* Setting both simultaneously means at least one must fail */
		if (options == WDIOS_DISABLECARD)
			ret = wm831x_wdt_start(wm831x);

		if (options == WDIOS_ENABLECARD)
			ret = wm831x_wdt_stop(wm831x);
		break;
	}

	case WDIOC_KEEPALIVE:
		ret = wm831x_wdt_kick(wm831x);
		break;

	case WDIOC_SETTIMEOUT:
		ret = get_user(time, p);
		if (ret)
			break;

		if (time == 0) {
			if (nowayout)
				ret = -EINVAL;
			else
				wm831x_wdt_stop(wm831x);
			break;
		}

		for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
			if (wm831x_wdt_cfgs[i].time == time)
				break;
		if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
			ret = -EINVAL;
		else
			ret = wm831x_wdt_set_timeout(wm831x,
						     wm831x_wdt_cfgs[i].val);
		break;

	case WDIOC_GETTIMEOUT:
		reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
		reg &= WM831X_WDOG_TO_MASK;
		for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
			if (wm831x_wdt_cfgs[i].val == reg)
				break;
		if (i == ARRAY_SIZE(wm831x_wdt_cfgs)) {
			dev_warn(wm831x->dev,
				 "Unknown watchdog configuration: %x\n", reg);
			ret = -EINVAL;
		} else
			ret = put_user(wm831x_wdt_cfgs[i].time, p);

	}

	return ret;
}

static const struct file_operations wm831x_wdt_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = wm831x_wdt_write,
	.unlocked_ioctl = wm831x_wdt_ioctl,
	.open = wm831x_wdt_open,
	.release = wm831x_wdt_release,
};

static struct miscdevice wm831x_wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &wm831x_wdt_fops,
};

static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
{
	struct wm831x_pdata *chip_pdata;
	struct wm831x_watchdog_pdata *pdata;
	int reg, ret;

	wm831x = dev_get_drvdata(pdev->dev.parent);

	ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
	if (ret < 0) {
		dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
			ret);
		goto err;
	}
	reg = ret;

	if (reg & WM831X_WDOG_DEBUG)
		dev_warn(wm831x->dev, "Watchdog is paused\n");

	/* Apply any configuration */
	if (pdev->dev.parent->platform_data) {
		chip_pdata = pdev->dev.parent->platform_data;
		pdata = chip_pdata->watchdog;
	} else {
		pdata = NULL;
	}

	if (pdata) {
		reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
			 WM831X_WDOG_RST_SRC);

		reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
		reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
		reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;

		if (pdata->update_gpio) {
			ret = gpio_request(pdata->update_gpio,
					   "Watchdog update");
			if (ret < 0) {
				dev_err(wm831x->dev,
					"Failed to request update GPIO: %d\n",
					ret);
				goto err;
			}

			ret = gpio_direction_output(pdata->update_gpio, 0);
			if (ret != 0) {
				dev_err(wm831x->dev,
					"gpio_direction_output returned: %d\n",
					ret);
				goto err_gpio;
			}

			update_gpio = pdata->update_gpio;

			/* Make sure the watchdog takes hardware updates */
			reg |= WM831X_WDOG_RST_SRC;
		}

		ret = wm831x_reg_unlock(wm831x);
		if (ret == 0) {
			ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
			wm831x_reg_lock(wm831x);
		} else {
			dev_err(wm831x->dev,
				"Failed to unlock security key: %d\n", ret);
			goto err_gpio;
		}
	}

	wm831x_wdt_miscdev.parent = &pdev->dev;

	ret = misc_register(&wm831x_wdt_miscdev);
	if (ret != 0) {
		dev_err(wm831x->dev, "Failed to register miscdev: %d\n", ret);
		goto err_gpio;
	}

	return 0;

err_gpio:
	if (update_gpio) {
		gpio_free(update_gpio);
		update_gpio = 0;
	}
err:
	return ret;
}

static int __devexit wm831x_wdt_remove(struct platform_device *pdev)
{
	if (update_gpio) {
		gpio_free(update_gpio);
		update_gpio = 0;
	}

	misc_deregister(&wm831x_wdt_miscdev);

	return 0;
}

static struct platform_driver wm831x_wdt_driver = {
	.probe = wm831x_wdt_probe,
	.remove = __devexit_p(wm831x_wdt_remove),
	.driver = {
		.name = "wm831x-watchdog",
	},
};

static int __init wm831x_wdt_init(void)
{
	return platform_driver_register(&wm831x_wdt_driver);
}
module_init(wm831x_wdt_init);

static void __exit wm831x_wdt_exit(void)
{
	platform_driver_unregister(&wm831x_wdt_driver);
}
module_exit(wm831x_wdt_exit);

MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM831x Watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-watchdog");
Commit	Line	Data
502a0106 MB	1	/*
	2	* Watchdog driver for the wm831x PMICs
	3	*
	4	* Copyright (C) 2009 Wolfson Microelectronics
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation
	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/moduleparam.h>
	13	#include <linux/types.h>
	14	#include <linux/kernel.h>
	15	#include <linux/fs.h>
	16	#include <linux/miscdevice.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/watchdog.h>
	19	#include <linux/uaccess.h>
	20	#include <linux/gpio.h>
	21
	22	#include <linux/mfd/wm831x/core.h>
	23	#include <linux/mfd/wm831x/pdata.h>
	24	#include <linux/mfd/wm831x/watchdog.h>
	25
	26	static int nowayout = WATCHDOG_NOWAYOUT;
	27	module_param(nowayout, int, 0);
	28	MODULE_PARM_DESC(nowayout,
	29	"Watchdog cannot be stopped once started (default="
	30	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	31
	32	static unsigned long wm831x_wdt_users;
	33	static struct miscdevice wm831x_wdt_miscdev;
	34	static int wm831x_wdt_expect_close;
	35	static DEFINE_MUTEX(wdt_mutex);
	36	static struct wm831x *wm831x;
	37	static unsigned int update_gpio;
	38	static unsigned int update_state;
	39
	40	/* We can't use the sub-second values here but they're included
	41	* for completeness. */
	42	static struct {
	43	int time; /* Seconds */
	44	u16 val; /* WDOG_TO value */
	45	} wm831x_wdt_cfgs[] = {
	46	{ 1, 2 },
	47	{ 2, 3 },
	48	{ 4, 4 },
	49	{ 8, 5 },
	50	{ 16, 6 },
	51	{ 32, 7 },
	52	{ 33, 7 }, /* Actually 32.768s so include both, others round down */
	53	};
	54
	55	static int wm831x_wdt_set_timeout(struct wm831x *wm831x, u16 value)
	56	{
	57	int ret;
	58
	59	mutex_lock(&wdt_mutex);
	60
	61	ret = wm831x_reg_unlock(wm831x);
	62	if (ret == 0) {
	63	ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
	64	WM831X_WDOG_TO_MASK, value);
65	wm831x_reg_lock(wm831x);
66	} else {
67	dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
68	ret);
69	}
70
71	mutex_unlock(&wdt_mutex);
72
73	return ret;
74	}
75
76	static int wm831x_wdt_start(struct wm831x *wm831x)
77	{
78	int ret;
79
80	mutex_lock(&wdt_mutex);
81
82	ret = wm831x_reg_unlock(wm831x);
83	if (ret == 0) {
84	ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
85	WM831X_WDOG_ENA, WM831X_WDOG_ENA);
86	wm831x_reg_lock(wm831x);
87	} else {
88	dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
89	ret);
90	}
91
92	mutex_unlock(&wdt_mutex);
93
94	return ret;
95	}
96
97	static int wm831x_wdt_stop(struct wm831x *wm831x)
98	{
99	int ret;
100
101	mutex_lock(&wdt_mutex);
102
103	ret = wm831x_reg_unlock(wm831x);
104	if (ret == 0) {
105	ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
106	WM831X_WDOG_ENA, 0);
107	wm831x_reg_lock(wm831x);
108	} else {
109	dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
110	ret);
111	}
112
113	mutex_unlock(&wdt_mutex);
114
115	return ret;
116	}
117
118	static int wm831x_wdt_kick(struct wm831x *wm831x)
119	{
120	int ret;
121	u16 reg;
122
123	mutex_lock(&wdt_mutex);
124
125	if (update_gpio) {
126	gpio_set_value_cansleep(update_gpio, update_state);
127	update_state = !update_state;
128	ret = 0;
129	goto out;
130	}
131
132
133	reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
134
135	if (!(reg & WM831X_WDOG_RST_SRC)) {
136	dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
137	ret = -EINVAL;
138	goto out;
139	}
140
141	reg \|= WM831X_WDOG_RESET;
142
143	ret = wm831x_reg_unlock(wm831x);
144	if (ret == 0) {
145	ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
146	wm831x_reg_lock(wm831x);
147	} else {
148	dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
149	ret);
150	}
151
152	out:
153	mutex_unlock(&wdt_mutex);
154
155	return ret;
156	}
157
158	static int wm831x_wdt_open(struct inode inode, struct file file)
159	{
160	int ret;
161
162	if (!wm831x)
163	return -ENODEV;
164
165	if (test_and_set_bit(0, &wm831x_wdt_users))
166	return -EBUSY;
167
168	ret = wm831x_wdt_start(wm831x);
169	if (ret != 0)
170	return ret;
171
172	return nonseekable_open(inode, file);
173	}
174
175	static int wm831x_wdt_release(struct inode inode, struct file file)
176	{
177	if (wm831x_wdt_expect_close)
178	wm831x_wdt_stop(wm831x);
179	else {
180	dev_warn(wm831x->dev, "Watchdog device closed uncleanly\n");
181	wm831x_wdt_kick(wm831x);
182	}
183
184	clear_bit(0, &wm831x_wdt_users);
185
186	return 0;
187	}
188
189	static ssize_t wm831x_wdt_write(struct file *file,
190	const char __user *data, size_t count,
191	loff_t *ppos)
192	{
193	size_t i;
194
195	if (count) {
196	wm831x_wdt_kick(wm831x);
197
198	if (!nowayout) {
199	/* In case it was set long ago */
200	wm831x_wdt_expect_close = 0;
201
202	/* scan to see whether or not we got the magic
203	character */
204	for (i = 0; i != count; i++) {
205	char c;
206	if (get_user(c, data + i))
207	return -EFAULT;
208	if (c == 'V')
209	wm831x_wdt_expect_close = 42;
210	}
211	}
212	}
213	return count;
214	}
215
42747d71	216	static const struct watchdog_info ident = {
502a0106 MB	217	.options = WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	218	.identity = "WM831x Watchdog",
	219	};
	220
	221	static long wm831x_wdt_ioctl(struct file *file, unsigned int cmd,
	222	unsigned long arg)
	223	{
	224	int ret = -ENOTTY, time, i;
	225	void __user argp = (void __user )arg;
	226	int __user *p = argp;
	227	u16 reg;
	228
	229	switch (cmd) {
	230	case WDIOC_GETSUPPORT:
	231	ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
	232	break;
	233
	234	case WDIOC_GETSTATUS:
	235	case WDIOC_GETBOOTSTATUS:
	236	ret = put_user(0, p);
	237	break;
	238
	239	case WDIOC_SETOPTIONS:
	240	{
	241	int options;
	242
	243	if (get_user(options, p))
	244	return -EFAULT;
	245
	246	ret = -EINVAL;
	247
	248	/* Setting both simultaneously means at least one must fail */
	249	if (options == WDIOS_DISABLECARD)
	250	ret = wm831x_wdt_start(wm831x);
	251
	252	if (options == WDIOS_ENABLECARD)
	253	ret = wm831x_wdt_stop(wm831x);
	254	break;
	255	}
	256
	257	case WDIOC_KEEPALIVE:
	258	ret = wm831x_wdt_kick(wm831x);
	259	break;
	260
	261	case WDIOC_SETTIMEOUT:
	262	ret = get_user(time, p);
	263	if (ret)
	264	break;
	265
	266	if (time == 0) {
	267	if (nowayout)
	268	ret = -EINVAL;
	269	else
	270	wm831x_wdt_stop(wm831x);
	271	break;
	272	}
	273
	274	for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
	275	if (wm831x_wdt_cfgs[i].time == time)
	276	break;
	277	if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
	278	ret = -EINVAL;
	279	else
	280	ret = wm831x_wdt_set_timeout(wm831x,
281	wm831x_wdt_cfgs[i].val);
282	break;
283
284	case WDIOC_GETTIMEOUT:
285	reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
286	reg &= WM831X_WDOG_TO_MASK;
287	for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
288	if (wm831x_wdt_cfgs[i].val == reg)
289	break;
290	if (i == ARRAY_SIZE(wm831x_wdt_cfgs)) {
291	dev_warn(wm831x->dev,
292	"Unknown watchdog configuration: %x\n", reg);
293	ret = -EINVAL;
294	} else
295	ret = put_user(wm831x_wdt_cfgs[i].time, p);
296
297	}
298
299	return ret;
300	}
301
302	static const struct file_operations wm831x_wdt_fops = {
303	.owner = THIS_MODULE,
304	.llseek = no_llseek,
305	.write = wm831x_wdt_write,
306	.unlocked_ioctl = wm831x_wdt_ioctl,
307	.open = wm831x_wdt_open,
308	.release = wm831x_wdt_release,
309	};
310
311	static struct miscdevice wm831x_wdt_miscdev = {
312	.minor = WATCHDOG_MINOR,
313	.name = "watchdog",
314	.fops = &wm831x_wdt_fops,
315	};
316
317	static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
318	{
319	struct wm831x_pdata *chip_pdata;
320	struct wm831x_watchdog_pdata *pdata;
321	int reg, ret;
322
323	wm831x = dev_get_drvdata(pdev->dev.parent);
324
325	ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
326	if (ret < 0) {
327	dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
328	ret);
329	goto err;
330	}
331	reg = ret;
332
333	if (reg & WM831X_WDOG_DEBUG)
334	dev_warn(wm831x->dev, "Watchdog is paused\n");
335
336	/* Apply any configuration */
337	if (pdev->dev.parent->platform_data) {
338	chip_pdata = pdev->dev.parent->platform_data;
339	pdata = chip_pdata->watchdog;
340	} else {
341	pdata = NULL;
342	}
343
344	if (pdata) {
345	reg &= ~(WM831X_WDOG_SECACT_MASK \| WM831X_WDOG_PRIMACT_MASK \|
346	WM831X_WDOG_RST_SRC);
347
348	reg \|= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
349	reg \|= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
350	reg \|= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
351
352	if (pdata->update_gpio) {
353	ret = gpio_request(pdata->update_gpio,
354	"Watchdog update");
355	if (ret < 0) {
356	dev_err(wm831x->dev,
357	"Failed to request update GPIO: %d\n",
358	ret);
359	goto err;
360	}
361
362	ret = gpio_direction_output(pdata->update_gpio, 0);
363	if (ret != 0) {
364	dev_err(wm831x->dev,
365	"gpio_direction_output returned: %d\n",
366	ret);
367	goto err_gpio;
368	}
369
370	update_gpio = pdata->update_gpio;
371
372	/* Make sure the watchdog takes hardware updates */
373	reg \|= WM831X_WDOG_RST_SRC;
374	}
375
376	ret = wm831x_reg_unlock(wm831x);
377	if (ret == 0) {
378	ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
379	wm831x_reg_lock(wm831x);
380	} else {
381	dev_err(wm831x->dev,
382	"Failed to unlock security key: %d\n", ret);
383	goto err_gpio;
384	}
385	}
386
387	wm831x_wdt_miscdev.parent = &pdev->dev;
388
389	ret = misc_register(&wm831x_wdt_miscdev);
390	if (ret != 0) {
391	dev_err(wm831x->dev, "Failed to register miscdev: %d\n", ret);
392	goto err_gpio;
393	}
394
395	return 0;
396
397	err_gpio:
398	if (update_gpio) {
399	gpio_free(update_gpio);
400	update_gpio = 0;
401	}
402	err:
403	return ret;
404	}
405
406	static int __devexit wm831x_wdt_remove(struct platform_device *pdev)
407	{
408	if (update_gpio) {
409	gpio_free(update_gpio);
410	update_gpio = 0;
411	}
412
413	misc_deregister(&wm831x_wdt_miscdev);
414
415	return 0;
416	}
417
418	static struct platform_driver wm831x_wdt_driver = {
419	.probe = wm831x_wdt_probe,
420	.remove = __devexit_p(wm831x_wdt_remove),
421	.driver = {
422	.name = "wm831x-watchdog",
423	},
424	};
425
426	static int __init wm831x_wdt_init(void)
427	{
428	return platform_driver_register(&wm831x_wdt_driver);
429	}
430	module_init(wm831x_wdt_init);
431
432	static void __exit wm831x_wdt_exit(void)
433	{
434	platform_driver_unregister(&wm831x_wdt_driver);
435	}
436	module_exit(wm831x_wdt_exit);
437
438	MODULE_AUTHOR("Mark Brown");
439	MODULE_DESCRIPTION("WM831x Watchdog");
440	MODULE_LICENSE("GPL");
441	MODULE_ALIAS("platform:wm831x-watchdog");