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v3.1
  1/*
  2 * Copyright 2010-2011 Picochip Ltd., Jamie Iles
  3 * http://www.picochip.com
  4 *
  5 * This program is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU General Public License
  7 * as published by the Free Software Foundation; either version
  8 * 2 of the License, or (at your option) any later version.
  9 *
 10 * This file implements a driver for the Synopsys DesignWare watchdog device
 11 * in the many ARM subsystems. The watchdog has 16 different timeout periods
 12 * and these are a function of the input clock frequency.
 13 *
 14 * The DesignWare watchdog cannot be stopped once it has been started so we
 15 * use a software timer to implement a ping that will keep the watchdog alive.
 16 * If we receive an expected close for the watchdog then we keep the timer
 17 * running, otherwise the timer is stopped and the watchdog will expire.
 18 */
 19#define pr_fmt(fmt) "dw_wdt: " fmt
 
 20
 21#include <linux/bitops.h>
 22#include <linux/clk.h>
 23#include <linux/device.h>
 24#include <linux/err.h>
 25#include <linux/fs.h>
 26#include <linux/io.h>
 27#include <linux/kernel.h>
 28#include <linux/miscdevice.h>
 29#include <linux/module.h>
 30#include <linux/moduleparam.h>
 
 
 31#include <linux/pm.h>
 32#include <linux/platform_device.h>
 33#include <linux/spinlock.h>
 34#include <linux/timer.h>
 35#include <linux/uaccess.h>
 36#include <linux/watchdog.h>
 37
 38#define WDOG_CONTROL_REG_OFFSET		    0x00
 39#define WDOG_CONTROL_REG_WDT_EN_MASK	    0x01
 40#define WDOG_TIMEOUT_RANGE_REG_OFFSET	    0x04
 
 41#define WDOG_CURRENT_COUNT_REG_OFFSET	    0x08
 42#define WDOG_COUNTER_RESTART_REG_OFFSET     0x0c
 43#define WDOG_COUNTER_RESTART_KICK_VALUE	    0x76
 44
 45/* The maximum TOP (timeout period) value that can be set in the watchdog. */
 46#define DW_WDT_MAX_TOP		15
 47
 48static int nowayout = WATCHDOG_NOWAYOUT;
 49module_param(nowayout, int, 0);
 
 
 50MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
 51		 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 52
 53#define WDT_TIMEOUT		(HZ / 2)
 54
 55static struct {
 56	spinlock_t		lock;
 57	void __iomem		*regs;
 58	struct clk		*clk;
 59	unsigned long		in_use;
 60	unsigned long		next_heartbeat;
 61	struct timer_list	timer;
 62	int			expect_close;
 63} dw_wdt;
 
 64
 65static inline int dw_wdt_is_enabled(void)
 66{
 67	return readl(dw_wdt.regs + WDOG_CONTROL_REG_OFFSET) &
 68		WDOG_CONTROL_REG_WDT_EN_MASK;
 69}
 70
 71static inline int dw_wdt_top_in_seconds(unsigned top)
 72{
 73	/*
 74	 * There are 16 possible timeout values in 0..15 where the number of
 75	 * cycles is 2 ^ (16 + i) and the watchdog counts down.
 76	 */
 77	return (1 << (16 + top)) / clk_get_rate(dw_wdt.clk);
 78}
 79
 80static int dw_wdt_get_top(void)
 81{
 82	int top = readl(dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
 83
 84	return dw_wdt_top_in_seconds(top);
 85}
 86
 87static inline void dw_wdt_set_next_heartbeat(void)
 88{
 89	dw_wdt.next_heartbeat = jiffies + dw_wdt_get_top() * HZ;
 
 
 
 
 
 90}
 91
 92static int dw_wdt_set_top(unsigned top_s)
 93{
 
 94	int i, top_val = DW_WDT_MAX_TOP;
 95
 96	/*
 97	 * Iterate over the timeout values until we find the closest match. We
 98	 * always look for >=.
 99	 */
100	for (i = 0; i <= DW_WDT_MAX_TOP; ++i)
101		if (dw_wdt_top_in_seconds(i) >= top_s) {
102			top_val = i;
103			break;
104		}
105
106	/* Set the new value in the watchdog. */
107	writel(top_val, dw_wdt.regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
 
 
 
 
 
 
108
109	dw_wdt_set_next_heartbeat();
110
111	return dw_wdt_top_in_seconds(top_val);
112}
113
114static void dw_wdt_keepalive(void)
115{
116	writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt.regs +
117	       WDOG_COUNTER_RESTART_REG_OFFSET);
118}
119
120static void dw_wdt_ping(unsigned long data)
121{
122	if (time_before(jiffies, dw_wdt.next_heartbeat) ||
123	    (!nowayout && !dw_wdt.in_use)) {
124		dw_wdt_keepalive();
125		mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
126	} else
127		pr_crit("keepalive missed, machine will reset\n");
128}
129
130static int dw_wdt_open(struct inode *inode, struct file *filp)
131{
132	if (test_and_set_bit(0, &dw_wdt.in_use))
133		return -EBUSY;
134
135	/* Make sure we don't get unloaded. */
136	__module_get(THIS_MODULE);
137
138	spin_lock(&dw_wdt.lock);
139	if (!dw_wdt_is_enabled()) {
140		/*
141		 * The watchdog is not currently enabled. Set the timeout to
142		 * the maximum and then start it.
143		 */
144		dw_wdt_set_top(DW_WDT_MAX_TOP);
145		writel(WDOG_CONTROL_REG_WDT_EN_MASK,
146		       dw_wdt.regs + WDOG_CONTROL_REG_OFFSET);
147	}
148
149	dw_wdt_set_next_heartbeat();
150
151	spin_unlock(&dw_wdt.lock);
 
152
153	return nonseekable_open(inode, filp);
154}
155
156ssize_t dw_wdt_write(struct file *filp, const char __user *buf, size_t len,
157		     loff_t *offset)
158{
159	if (!len)
160		return 0;
161
162	if (!nowayout) {
163		size_t i;
164
165		dw_wdt.expect_close = 0;
166
167		for (i = 0; i < len; ++i) {
168			char c;
169
170			if (get_user(c, buf + i))
171				return -EFAULT;
172
173			if (c == 'V') {
174				dw_wdt.expect_close = 1;
175				break;
176			}
177		}
178	}
179
180	dw_wdt_set_next_heartbeat();
181	mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
182
183	return len;
184}
185
186static u32 dw_wdt_time_left(void)
187{
188	return readl(dw_wdt.regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
189		clk_get_rate(dw_wdt.clk);
 
 
190}
191
192static const struct watchdog_info dw_wdt_ident = {
193	.options	= WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
194			  WDIOF_MAGICCLOSE,
195	.identity	= "Synopsys DesignWare Watchdog",
196};
197
198static long dw_wdt_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
199{
200	unsigned long val;
201	int timeout;
202
203	switch (cmd) {
204	case WDIOC_GETSUPPORT:
205		return copy_to_user((struct watchdog_info *)arg, &dw_wdt_ident,
206				    sizeof(dw_wdt_ident)) ? -EFAULT : 0;
207
208	case WDIOC_GETSTATUS:
209	case WDIOC_GETBOOTSTATUS:
210		return put_user(0, (int *)arg);
211
212	case WDIOC_KEEPALIVE:
213		dw_wdt_set_next_heartbeat();
214		return 0;
215
216	case WDIOC_SETTIMEOUT:
217		if (get_user(val, (int __user *)arg))
218			return -EFAULT;
219		timeout = dw_wdt_set_top(val);
220		return put_user(timeout , (int __user *)arg);
221
222	case WDIOC_GETTIMEOUT:
223		return put_user(dw_wdt_get_top(), (int __user *)arg);
224
225	case WDIOC_GETTIMELEFT:
226		/* Get the time left until expiry. */
227		if (get_user(val, (int __user *)arg))
228			return -EFAULT;
229		return put_user(dw_wdt_time_left(), (int __user *)arg);
230
231	default:
232		return -ENOTTY;
233	}
234}
235
236static int dw_wdt_release(struct inode *inode, struct file *filp)
237{
238	clear_bit(0, &dw_wdt.in_use);
239
240	if (!dw_wdt.expect_close) {
241		del_timer(&dw_wdt.timer);
242
243		if (!nowayout)
244			pr_crit("unexpected close, system will reboot soon\n");
245		else
246			pr_crit("watchdog cannot be disabled, system will reboot soon\n");
247	}
248
249	dw_wdt.expect_close = 0;
250
251	return 0;
252}
253
254#ifdef CONFIG_PM
255static int dw_wdt_suspend(struct device *dev)
256{
257	clk_disable(dw_wdt.clk);
 
 
258
259	return 0;
260}
261
262static int dw_wdt_resume(struct device *dev)
263{
264	int err = clk_enable(dw_wdt.clk);
 
265
266	if (err)
267		return err;
268
269	dw_wdt_keepalive();
270
271	return 0;
272}
 
273
274static const struct dev_pm_ops dw_wdt_pm_ops = {
275	.suspend	= dw_wdt_suspend,
276	.resume		= dw_wdt_resume,
277};
278#endif /* CONFIG_PM */
279
280static const struct file_operations wdt_fops = {
281	.owner		= THIS_MODULE,
282	.llseek		= no_llseek,
283	.open		= dw_wdt_open,
284	.write		= dw_wdt_write,
285	.unlocked_ioctl	= dw_wdt_ioctl,
286	.release	= dw_wdt_release
287};
288
289static struct miscdevice dw_wdt_miscdev = {
290	.fops		= &wdt_fops,
291	.name		= "watchdog",
292	.minor		= WATCHDOG_MINOR,
293};
294
295static int __devinit dw_wdt_drv_probe(struct platform_device *pdev)
296{
 
 
 
 
297	int ret;
298	struct resource *mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
299
300	if (!mem)
301		return -EINVAL;
302
303	if (!devm_request_mem_region(&pdev->dev, mem->start, resource_size(mem),
304				     "dw_wdt"))
305		return -ENOMEM;
306
307	dw_wdt.regs = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
308	if (!dw_wdt.regs)
309		return -ENOMEM;
310
311	dw_wdt.clk = clk_get(&pdev->dev, NULL);
312	if (IS_ERR(dw_wdt.clk))
313		return PTR_ERR(dw_wdt.clk);
 
 
 
 
 
314
315	ret = clk_enable(dw_wdt.clk);
316	if (ret)
317		goto out_put_clk;
318
319	spin_lock_init(&dw_wdt.lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
320
321	ret = misc_register(&dw_wdt_miscdev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
322	if (ret)
323		goto out_disable_clk;
324
325	dw_wdt_set_next_heartbeat();
326	setup_timer(&dw_wdt.timer, dw_wdt_ping, 0);
327	mod_timer(&dw_wdt.timer, jiffies + WDT_TIMEOUT);
 
 
328
329	return 0;
330
331out_disable_clk:
332	clk_disable(dw_wdt.clk);
333out_put_clk:
334	clk_put(dw_wdt.clk);
335
336	return ret;
337}
338
339static int __devexit dw_wdt_drv_remove(struct platform_device *pdev)
340{
341	misc_deregister(&dw_wdt_miscdev);
342
343	clk_disable(dw_wdt.clk);
344	clk_put(dw_wdt.clk);
 
345
346	return 0;
347}
348
 
 
 
 
 
 
 
 
349static struct platform_driver dw_wdt_driver = {
350	.probe		= dw_wdt_drv_probe,
351	.remove		= __devexit_p(dw_wdt_drv_remove),
352	.driver		= {
353		.name	= "dw_wdt",
354		.owner	= THIS_MODULE,
355#ifdef CONFIG_PM
356		.pm	= &dw_wdt_pm_ops,
357#endif /* CONFIG_PM */
358	},
359};
360
361static int __init dw_wdt_watchdog_init(void)
362{
363	return platform_driver_register(&dw_wdt_driver);
364}
365module_init(dw_wdt_watchdog_init);
366
367static void __exit dw_wdt_watchdog_exit(void)
368{
369	platform_driver_unregister(&dw_wdt_driver);
370}
371module_exit(dw_wdt_watchdog_exit);
372
373MODULE_AUTHOR("Jamie Iles");
374MODULE_DESCRIPTION("Synopsys DesignWare Watchdog Driver");
375MODULE_LICENSE("GPL");
376MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
v4.10.11
  1/*
  2 * Copyright 2010-2011 Picochip Ltd., Jamie Iles
  3 * http://www.picochip.com
  4 *
  5 * This program is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU General Public License
  7 * as published by the Free Software Foundation; either version
  8 * 2 of the License, or (at your option) any later version.
  9 *
 10 * This file implements a driver for the Synopsys DesignWare watchdog device
 11 * in the many subsystems. The watchdog has 16 different timeout periods
 12 * and these are a function of the input clock frequency.
 13 *
 14 * The DesignWare watchdog cannot be stopped once it has been started so we
 15 * do not implement a stop function. The watchdog core will continue to send
 16 * heartbeat requests after the watchdog device has been closed.
 
 17 */
 18
 19#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 20
 21#include <linux/bitops.h>
 22#include <linux/clk.h>
 23#include <linux/delay.h>
 24#include <linux/err.h>
 
 25#include <linux/io.h>
 26#include <linux/kernel.h>
 
 27#include <linux/module.h>
 28#include <linux/moduleparam.h>
 29#include <linux/notifier.h>
 30#include <linux/of.h>
 31#include <linux/pm.h>
 32#include <linux/platform_device.h>
 33#include <linux/reboot.h>
 
 
 34#include <linux/watchdog.h>
 35
 36#define WDOG_CONTROL_REG_OFFSET		    0x00
 37#define WDOG_CONTROL_REG_WDT_EN_MASK	    0x01
 38#define WDOG_TIMEOUT_RANGE_REG_OFFSET	    0x04
 39#define WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT    4
 40#define WDOG_CURRENT_COUNT_REG_OFFSET	    0x08
 41#define WDOG_COUNTER_RESTART_REG_OFFSET     0x0c
 42#define WDOG_COUNTER_RESTART_KICK_VALUE	    0x76
 43
 44/* The maximum TOP (timeout period) value that can be set in the watchdog. */
 45#define DW_WDT_MAX_TOP		15
 46
 47#define DW_WDT_DEFAULT_SECONDS	30
 48
 49static bool nowayout = WATCHDOG_NOWAYOUT;
 50module_param(nowayout, bool, 0);
 51MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
 52		 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 53
 54struct dw_wdt {
 
 
 
 55	void __iomem		*regs;
 56	struct clk		*clk;
 57	unsigned long		rate;
 58	struct notifier_block	restart_handler;
 59	struct watchdog_device	wdd;
 60};
 61
 62#define to_dw_wdt(wdd)	container_of(wdd, struct dw_wdt, wdd)
 63
 64static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt)
 65{
 66	return readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET) &
 67		WDOG_CONTROL_REG_WDT_EN_MASK;
 68}
 69
 70static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top)
 71{
 72	/*
 73	 * There are 16 possible timeout values in 0..15 where the number of
 74	 * cycles is 2 ^ (16 + i) and the watchdog counts down.
 75	 */
 76	return (1U << (16 + top)) / dw_wdt->rate;
 77}
 78
 79static int dw_wdt_get_top(struct dw_wdt *dw_wdt)
 80{
 81	int top = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF;
 82
 83	return dw_wdt_top_in_seconds(dw_wdt, top);
 84}
 85
 86static int dw_wdt_ping(struct watchdog_device *wdd)
 87{
 88	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
 89
 90	writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt->regs +
 91	       WDOG_COUNTER_RESTART_REG_OFFSET);
 92
 93	return 0;
 94}
 95
 96static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s)
 97{
 98	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
 99	int i, top_val = DW_WDT_MAX_TOP;
100
101	/*
102	 * Iterate over the timeout values until we find the closest match. We
103	 * always look for >=.
104	 */
105	for (i = 0; i <= DW_WDT_MAX_TOP; ++i)
106		if (dw_wdt_top_in_seconds(dw_wdt, i) >= top_s) {
107			top_val = i;
108			break;
109		}
110
111	/*
112	 * Set the new value in the watchdog.  Some versions of dw_wdt
113	 * have have TOPINIT in the TIMEOUT_RANGE register (as per
114	 * CP_WDT_DUAL_TOP in WDT_COMP_PARAMS_1).  On those we
115	 * effectively get a pat of the watchdog right here.
116	 */
117	writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT,
118	       dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
119
120	wdd->timeout = dw_wdt_top_in_seconds(dw_wdt, top_val);
121
122	return 0;
123}
124
125static int dw_wdt_start(struct watchdog_device *wdd)
126{
127	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
 
 
128
129	dw_wdt_set_timeout(wdd, wdd->timeout);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
130
131	set_bit(WDOG_HW_RUNNING, &wdd->status);
132
133	writel(WDOG_CONTROL_REG_WDT_EN_MASK,
134	       dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
135
136	return 0;
137}
138
139static int dw_wdt_restart_handle(struct notifier_block *this,
140				 unsigned long mode, void *cmd)
141{
142	struct dw_wdt *dw_wdt;
143	u32 val;
 
 
 
 
 
144
145	dw_wdt = container_of(this, struct dw_wdt, restart_handler);
 
146
147	writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET);
148	val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
149	if (val & WDOG_CONTROL_REG_WDT_EN_MASK)
150		writel(WDOG_COUNTER_RESTART_KICK_VALUE,
151		       dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET);
152	else
153		writel(WDOG_CONTROL_REG_WDT_EN_MASK,
154		       dw_wdt->regs + WDOG_CONTROL_REG_OFFSET);
 
155
156	/* wait for reset to assert... */
157	mdelay(500);
158
159	return NOTIFY_DONE;
160}
161
162static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd)
163{
164	struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
165
166	return readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET) /
167		dw_wdt->rate;
168}
169
170static const struct watchdog_info dw_wdt_ident = {
171	.options	= WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
172			  WDIOF_MAGICCLOSE,
173	.identity	= "Synopsys DesignWare Watchdog",
174};
175
176static const struct watchdog_ops dw_wdt_ops = {
177	.owner		= THIS_MODULE,
178	.start		= dw_wdt_start,
179	.ping		= dw_wdt_ping,
180	.set_timeout	= dw_wdt_set_timeout,
181	.get_timeleft	= dw_wdt_get_timeleft,
182};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
183
184#ifdef CONFIG_PM_SLEEP
185static int dw_wdt_suspend(struct device *dev)
186{
187	struct dw_wdt *dw_wdt = dev_get_drvdata(dev);
188
189	clk_disable_unprepare(dw_wdt->clk);
190
191	return 0;
192}
193
194static int dw_wdt_resume(struct device *dev)
195{
196	struct dw_wdt *dw_wdt = dev_get_drvdata(dev);
197	int err = clk_prepare_enable(dw_wdt->clk);
198
199	if (err)
200		return err;
201
202	dw_wdt_ping(&dw_wdt->wdd);
203
204	return 0;
205}
206#endif /* CONFIG_PM_SLEEP */
207
208static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume);
 
 
 
 
209
210static int dw_wdt_drv_probe(struct platform_device *pdev)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
211{
212	struct device *dev = &pdev->dev;
213	struct watchdog_device *wdd;
214	struct dw_wdt *dw_wdt;
215	struct resource *mem;
216	int ret;
 
 
 
 
 
 
 
 
217
218	dw_wdt = devm_kzalloc(dev, sizeof(*dw_wdt), GFP_KERNEL);
219	if (!dw_wdt)
220		return -ENOMEM;
221
222	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
223	dw_wdt->regs = devm_ioremap_resource(dev, mem);
224	if (IS_ERR(dw_wdt->regs))
225		return PTR_ERR(dw_wdt->regs);
226
227	dw_wdt->clk = devm_clk_get(dev, NULL);
228	if (IS_ERR(dw_wdt->clk))
229		return PTR_ERR(dw_wdt->clk);
230
231	ret = clk_prepare_enable(dw_wdt->clk);
232	if (ret)
233		return ret;
234
235	dw_wdt->rate = clk_get_rate(dw_wdt->clk);
236	if (dw_wdt->rate == 0) {
237		ret = -EINVAL;
238		goto out_disable_clk;
239	}
240
241	wdd = &dw_wdt->wdd;
242	wdd->info = &dw_wdt_ident;
243	wdd->ops = &dw_wdt_ops;
244	wdd->min_timeout = 1;
245	wdd->max_hw_heartbeat_ms =
246		dw_wdt_top_in_seconds(dw_wdt, DW_WDT_MAX_TOP) * 1000;
247	wdd->parent = dev;
248
249	watchdog_set_drvdata(wdd, dw_wdt);
250	watchdog_set_nowayout(wdd, nowayout);
251	watchdog_init_timeout(wdd, 0, dev);
252
253	/*
254	 * If the watchdog is already running, use its already configured
255	 * timeout. Otherwise use the default or the value provided through
256	 * devicetree.
257	 */
258	if (dw_wdt_is_enabled(dw_wdt)) {
259		wdd->timeout = dw_wdt_get_top(dw_wdt);
260		set_bit(WDOG_HW_RUNNING, &wdd->status);
261	} else {
262		wdd->timeout = DW_WDT_DEFAULT_SECONDS;
263		watchdog_init_timeout(wdd, 0, dev);
264	}
265
266	platform_set_drvdata(pdev, dw_wdt);
267
268	ret = watchdog_register_device(wdd);
269	if (ret)
270		goto out_disable_clk;
271
272	dw_wdt->restart_handler.notifier_call = dw_wdt_restart_handle;
273	dw_wdt->restart_handler.priority = 128;
274	ret = register_restart_handler(&dw_wdt->restart_handler);
275	if (ret)
276		pr_warn("cannot register restart handler\n");
277
278	return 0;
279
280out_disable_clk:
281	clk_disable_unprepare(dw_wdt->clk);
 
 
 
282	return ret;
283}
284
285static int dw_wdt_drv_remove(struct platform_device *pdev)
286{
287	struct dw_wdt *dw_wdt = platform_get_drvdata(pdev);
288
289	unregister_restart_handler(&dw_wdt->restart_handler);
290	watchdog_unregister_device(&dw_wdt->wdd);
291	clk_disable_unprepare(dw_wdt->clk);
292
293	return 0;
294}
295
296#ifdef CONFIG_OF
297static const struct of_device_id dw_wdt_of_match[] = {
298	{ .compatible = "snps,dw-wdt", },
299	{ /* sentinel */ }
300};
301MODULE_DEVICE_TABLE(of, dw_wdt_of_match);
302#endif
303
304static struct platform_driver dw_wdt_driver = {
305	.probe		= dw_wdt_drv_probe,
306	.remove		= dw_wdt_drv_remove,
307	.driver		= {
308		.name	= "dw_wdt",
309		.of_match_table = of_match_ptr(dw_wdt_of_match),
 
310		.pm	= &dw_wdt_pm_ops,
 
311	},
312};
313
314module_platform_driver(dw_wdt_driver);
 
 
 
 
 
 
 
 
 
 
315
316MODULE_AUTHOR("Jamie Iles");
317MODULE_DESCRIPTION("Synopsys DesignWare Watchdog Driver");
318MODULE_LICENSE("GPL");