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1/*
2 * Watchdog driver for IMX2 and later processors
3 *
4 * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
5 *
6 * some parts adapted by similar drivers from Darius Augulis and Vladimir
7 * Zapolskiy, additional improvements by Wim Van Sebroeck.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as published by
11 * the Free Software Foundation.
12 *
13 * NOTE: MX1 has a slightly different Watchdog than MX2 and later:
14 *
15 * MX1: MX2+:
16 * ---- -----
17 * Registers: 32-bit 16-bit
18 * Stopable timer: Yes No
19 * Need to enable clk: No Yes
20 * Halt on suspend: Manual Can be automatic
21 */
22
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/miscdevice.h>
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/platform_device.h>
29#include <linux/watchdog.h>
30#include <linux/clk.h>
31#include <linux/fs.h>
32#include <linux/io.h>
33#include <linux/uaccess.h>
34#include <linux/timer.h>
35#include <linux/jiffies.h>
36#include <mach/hardware.h>
37
38#define DRIVER_NAME "imx2-wdt"
39
40#define IMX2_WDT_WCR 0x00 /* Control Register */
41#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
42#define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */
43#define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */
44
45#define IMX2_WDT_WSR 0x02 /* Service Register */
46#define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */
47#define IMX2_WDT_SEQ2 0xAAAA /* -> service sequence 2 */
48
49#define IMX2_WDT_MAX_TIME 128
50#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */
51
52#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
53
54#define IMX2_WDT_STATUS_OPEN 0
55#define IMX2_WDT_STATUS_STARTED 1
56#define IMX2_WDT_EXPECT_CLOSE 2
57
58static struct {
59 struct clk *clk;
60 void __iomem *base;
61 unsigned timeout;
62 unsigned long status;
63 struct timer_list timer; /* Pings the watchdog when closed */
64} imx2_wdt;
65
66static struct miscdevice imx2_wdt_miscdev;
67
68static int nowayout = WATCHDOG_NOWAYOUT;
69module_param(nowayout, int, 0);
70MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
71 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72
73
74static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
75module_param(timeout, uint, 0);
76MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
77 __MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");
78
79static const struct watchdog_info imx2_wdt_info = {
80 .identity = "imx2+ watchdog",
81 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
82};
83
84static inline void imx2_wdt_setup(void)
85{
86 u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
87
88 /* Strip the old watchdog Time-Out value */
89 val &= ~IMX2_WDT_WCR_WT;
90 /* Generate reset if WDOG times out */
91 val &= ~IMX2_WDT_WCR_WRE;
92 /* Keep Watchdog Disabled */
93 val &= ~IMX2_WDT_WCR_WDE;
94 /* Set the watchdog's Time-Out value */
95 val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);
96
97 __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
98
99 /* enable the watchdog */
100 val |= IMX2_WDT_WCR_WDE;
101 __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
102}
103
104static inline void imx2_wdt_ping(void)
105{
106 __raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
107 __raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
108}
109
110static void imx2_wdt_timer_ping(unsigned long arg)
111{
112 /* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
113 imx2_wdt_ping();
114 mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
115}
116
117static void imx2_wdt_start(void)
118{
119 if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
120 /* at our first start we enable clock and do initialisations */
121 clk_enable(imx2_wdt.clk);
122
123 imx2_wdt_setup();
124 } else /* delete the timer that pings the watchdog after close */
125 del_timer_sync(&imx2_wdt.timer);
126
127 /* Watchdog is enabled - time to reload the timeout value */
128 imx2_wdt_ping();
129}
130
131static void imx2_wdt_stop(void)
132{
133 /* we don't need a clk_disable, it cannot be disabled once started.
134 * We use a timer to ping the watchdog while /dev/watchdog is closed */
135 imx2_wdt_timer_ping(0);
136}
137
138static void imx2_wdt_set_timeout(int new_timeout)
139{
140 u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
141
142 /* set the new timeout value in the WSR */
143 val &= ~IMX2_WDT_WCR_WT;
144 val |= WDOG_SEC_TO_COUNT(new_timeout);
145 __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
146}
147
148static int imx2_wdt_open(struct inode *inode, struct file *file)
149{
150 if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
151 return -EBUSY;
152
153 imx2_wdt_start();
154 return nonseekable_open(inode, file);
155}
156
157static int imx2_wdt_close(struct inode *inode, struct file *file)
158{
159 if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
160 imx2_wdt_stop();
161 else {
162 dev_crit(imx2_wdt_miscdev.parent,
163 "Unexpected close: Expect reboot!\n");
164 imx2_wdt_ping();
165 }
166
167 clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
168 clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
169 return 0;
170}
171
172static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
173 unsigned long arg)
174{
175 void __user *argp = (void __user *)arg;
176 int __user *p = argp;
177 int new_value;
178
179 switch (cmd) {
180 case WDIOC_GETSUPPORT:
181 return copy_to_user(argp, &imx2_wdt_info,
182 sizeof(struct watchdog_info)) ? -EFAULT : 0;
183
184 case WDIOC_GETSTATUS:
185 case WDIOC_GETBOOTSTATUS:
186 return put_user(0, p);
187
188 case WDIOC_KEEPALIVE:
189 imx2_wdt_ping();
190 return 0;
191
192 case WDIOC_SETTIMEOUT:
193 if (get_user(new_value, p))
194 return -EFAULT;
195 if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME))
196 return -EINVAL;
197 imx2_wdt_set_timeout(new_value);
198 imx2_wdt.timeout = new_value;
199 imx2_wdt_ping();
200
201 /* Fallthrough to return current value */
202 case WDIOC_GETTIMEOUT:
203 return put_user(imx2_wdt.timeout, p);
204
205 default:
206 return -ENOTTY;
207 }
208}
209
210static ssize_t imx2_wdt_write(struct file *file, const char __user *data,
211 size_t len, loff_t *ppos)
212{
213 size_t i;
214 char c;
215
216 if (len == 0) /* Can we see this even ? */
217 return 0;
218
219 clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
220 /* scan to see whether or not we got the magic character */
221 for (i = 0; i != len; i++) {
222 if (get_user(c, data + i))
223 return -EFAULT;
224 if (c == 'V')
225 set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
226 }
227
228 imx2_wdt_ping();
229 return len;
230}
231
232static const struct file_operations imx2_wdt_fops = {
233 .owner = THIS_MODULE,
234 .llseek = no_llseek,
235 .unlocked_ioctl = imx2_wdt_ioctl,
236 .open = imx2_wdt_open,
237 .release = imx2_wdt_close,
238 .write = imx2_wdt_write,
239};
240
241static struct miscdevice imx2_wdt_miscdev = {
242 .minor = WATCHDOG_MINOR,
243 .name = "watchdog",
244 .fops = &imx2_wdt_fops,
245};
246
247static int __init imx2_wdt_probe(struct platform_device *pdev)
248{
249 int ret;
250 int res_size;
251 struct resource *res;
252
253 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
254 if (!res) {
255 dev_err(&pdev->dev, "can't get device resources\n");
256 return -ENODEV;
257 }
258
259 res_size = resource_size(res);
260 if (!devm_request_mem_region(&pdev->dev, res->start, res_size,
261 res->name)) {
262 dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
263 res_size, res->start);
264 return -ENOMEM;
265 }
266
267 imx2_wdt.base = devm_ioremap_nocache(&pdev->dev, res->start, res_size);
268 if (!imx2_wdt.base) {
269 dev_err(&pdev->dev, "ioremap failed\n");
270 return -ENOMEM;
271 }
272
273 imx2_wdt.clk = clk_get(&pdev->dev, NULL);
274 if (IS_ERR(imx2_wdt.clk)) {
275 dev_err(&pdev->dev, "can't get Watchdog clock\n");
276 return PTR_ERR(imx2_wdt.clk);
277 }
278
279 imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
280 if (imx2_wdt.timeout != timeout)
281 dev_warn(&pdev->dev, "Initial timeout out of range! "
282 "Clamped from %u to %u\n", timeout, imx2_wdt.timeout);
283
284 setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);
285
286 imx2_wdt_miscdev.parent = &pdev->dev;
287 ret = misc_register(&imx2_wdt_miscdev);
288 if (ret)
289 goto fail;
290
291 dev_info(&pdev->dev,
292 "IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
293 imx2_wdt.timeout, nowayout);
294 return 0;
295
296fail:
297 imx2_wdt_miscdev.parent = NULL;
298 clk_put(imx2_wdt.clk);
299 return ret;
300}
301
302static int __exit imx2_wdt_remove(struct platform_device *pdev)
303{
304 misc_deregister(&imx2_wdt_miscdev);
305
306 if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
307 del_timer_sync(&imx2_wdt.timer);
308
309 dev_crit(imx2_wdt_miscdev.parent,
310 "Device removed: Expect reboot!\n");
311 } else
312 clk_put(imx2_wdt.clk);
313
314 imx2_wdt_miscdev.parent = NULL;
315 return 0;
316}
317
318static void imx2_wdt_shutdown(struct platform_device *pdev)
319{
320 if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
321 /* we are running, we need to delete the timer but will give
322 * max timeout before reboot will take place */
323 del_timer_sync(&imx2_wdt.timer);
324 imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
325 imx2_wdt_ping();
326
327 dev_crit(imx2_wdt_miscdev.parent,
328 "Device shutdown: Expect reboot!\n");
329 }
330}
331
332static const struct of_device_id imx2_wdt_dt_ids[] = {
333 { .compatible = "fsl,imx21-wdt", },
334 { /* sentinel */ }
335};
336
337static struct platform_driver imx2_wdt_driver = {
338 .remove = __exit_p(imx2_wdt_remove),
339 .shutdown = imx2_wdt_shutdown,
340 .driver = {
341 .name = DRIVER_NAME,
342 .owner = THIS_MODULE,
343 .of_match_table = imx2_wdt_dt_ids,
344 },
345};
346
347static int __init imx2_wdt_init(void)
348{
349 return platform_driver_probe(&imx2_wdt_driver, imx2_wdt_probe);
350}
351module_init(imx2_wdt_init);
352
353static void __exit imx2_wdt_exit(void)
354{
355 platform_driver_unregister(&imx2_wdt_driver);
356}
357module_exit(imx2_wdt_exit);
358
359MODULE_AUTHOR("Wolfram Sang");
360MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
361MODULE_LICENSE("GPL v2");
362MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
363MODULE_ALIAS("platform:" DRIVER_NAME);
1/*
2 * Watchdog driver for IMX2 and later processors
3 *
4 * Copyright (C) 2010 Wolfram Sang, Pengutronix e.K. <w.sang@pengutronix.de>
5 *
6 * some parts adapted by similar drivers from Darius Augulis and Vladimir
7 * Zapolskiy, additional improvements by Wim Van Sebroeck.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License version 2 as published by
11 * the Free Software Foundation.
12 *
13 * NOTE: MX1 has a slightly different Watchdog than MX2 and later:
14 *
15 * MX1: MX2+:
16 * ---- -----
17 * Registers: 32-bit 16-bit
18 * Stopable timer: Yes No
19 * Need to enable clk: No Yes
20 * Halt on suspend: Manual Can be automatic
21 */
22
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/miscdevice.h>
26#include <linux/module.h>
27#include <linux/moduleparam.h>
28#include <linux/platform_device.h>
29#include <linux/watchdog.h>
30#include <linux/clk.h>
31#include <linux/fs.h>
32#include <linux/io.h>
33#include <linux/uaccess.h>
34#include <linux/timer.h>
35#include <linux/jiffies.h>
36#include <mach/hardware.h>
37
38#define DRIVER_NAME "imx2-wdt"
39
40#define IMX2_WDT_WCR 0x00 /* Control Register */
41#define IMX2_WDT_WCR_WT (0xFF << 8) /* -> Watchdog Timeout Field */
42#define IMX2_WDT_WCR_WRE (1 << 3) /* -> WDOG Reset Enable */
43#define IMX2_WDT_WCR_WDE (1 << 2) /* -> Watchdog Enable */
44
45#define IMX2_WDT_WSR 0x02 /* Service Register */
46#define IMX2_WDT_SEQ1 0x5555 /* -> service sequence 1 */
47#define IMX2_WDT_SEQ2 0xAAAA /* -> service sequence 2 */
48
49#define IMX2_WDT_WRSR 0x04 /* Reset Status Register */
50#define IMX2_WDT_WRSR_TOUT (1 << 1) /* -> Reset due to Timeout */
51
52#define IMX2_WDT_MAX_TIME 128
53#define IMX2_WDT_DEFAULT_TIME 60 /* in seconds */
54
55#define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
56
57#define IMX2_WDT_STATUS_OPEN 0
58#define IMX2_WDT_STATUS_STARTED 1
59#define IMX2_WDT_EXPECT_CLOSE 2
60
61static struct {
62 struct clk *clk;
63 void __iomem *base;
64 unsigned timeout;
65 unsigned long status;
66 struct timer_list timer; /* Pings the watchdog when closed */
67} imx2_wdt;
68
69static struct miscdevice imx2_wdt_miscdev;
70
71static bool nowayout = WATCHDOG_NOWAYOUT;
72module_param(nowayout, bool, 0);
73MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
74 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
75
76
77static unsigned timeout = IMX2_WDT_DEFAULT_TIME;
78module_param(timeout, uint, 0);
79MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
80 __MODULE_STRING(IMX2_WDT_DEFAULT_TIME) ")");
81
82static const struct watchdog_info imx2_wdt_info = {
83 .identity = "imx2+ watchdog",
84 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
85};
86
87static inline void imx2_wdt_setup(void)
88{
89 u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
90
91 /* Strip the old watchdog Time-Out value */
92 val &= ~IMX2_WDT_WCR_WT;
93 /* Generate reset if WDOG times out */
94 val &= ~IMX2_WDT_WCR_WRE;
95 /* Keep Watchdog Disabled */
96 val &= ~IMX2_WDT_WCR_WDE;
97 /* Set the watchdog's Time-Out value */
98 val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);
99
100 __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
101
102 /* enable the watchdog */
103 val |= IMX2_WDT_WCR_WDE;
104 __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
105}
106
107static inline void imx2_wdt_ping(void)
108{
109 __raw_writew(IMX2_WDT_SEQ1, imx2_wdt.base + IMX2_WDT_WSR);
110 __raw_writew(IMX2_WDT_SEQ2, imx2_wdt.base + IMX2_WDT_WSR);
111}
112
113static void imx2_wdt_timer_ping(unsigned long arg)
114{
115 /* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
116 imx2_wdt_ping();
117 mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
118}
119
120static void imx2_wdt_start(void)
121{
122 if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
123 /* at our first start we enable clock and do initialisations */
124 clk_prepare_enable(imx2_wdt.clk);
125
126 imx2_wdt_setup();
127 } else /* delete the timer that pings the watchdog after close */
128 del_timer_sync(&imx2_wdt.timer);
129
130 /* Watchdog is enabled - time to reload the timeout value */
131 imx2_wdt_ping();
132}
133
134static void imx2_wdt_stop(void)
135{
136 /* we don't need a clk_disable, it cannot be disabled once started.
137 * We use a timer to ping the watchdog while /dev/watchdog is closed */
138 imx2_wdt_timer_ping(0);
139}
140
141static void imx2_wdt_set_timeout(int new_timeout)
142{
143 u16 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WCR);
144
145 /* set the new timeout value in the WSR */
146 val &= ~IMX2_WDT_WCR_WT;
147 val |= WDOG_SEC_TO_COUNT(new_timeout);
148 __raw_writew(val, imx2_wdt.base + IMX2_WDT_WCR);
149}
150
151static int imx2_wdt_open(struct inode *inode, struct file *file)
152{
153 if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
154 return -EBUSY;
155
156 imx2_wdt_start();
157 return nonseekable_open(inode, file);
158}
159
160static int imx2_wdt_close(struct inode *inode, struct file *file)
161{
162 if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
163 imx2_wdt_stop();
164 else {
165 dev_crit(imx2_wdt_miscdev.parent,
166 "Unexpected close: Expect reboot!\n");
167 imx2_wdt_ping();
168 }
169
170 clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
171 clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
172 return 0;
173}
174
175static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
176 unsigned long arg)
177{
178 void __user *argp = (void __user *)arg;
179 int __user *p = argp;
180 int new_value;
181 u16 val;
182
183 switch (cmd) {
184 case WDIOC_GETSUPPORT:
185 return copy_to_user(argp, &imx2_wdt_info,
186 sizeof(struct watchdog_info)) ? -EFAULT : 0;
187
188 case WDIOC_GETSTATUS:
189 return put_user(0, p);
190
191 case WDIOC_GETBOOTSTATUS:
192 val = __raw_readw(imx2_wdt.base + IMX2_WDT_WRSR);
193 new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
194 return put_user(new_value, p);
195
196 case WDIOC_KEEPALIVE:
197 imx2_wdt_ping();
198 return 0;
199
200 case WDIOC_SETTIMEOUT:
201 if (get_user(new_value, p))
202 return -EFAULT;
203 if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME))
204 return -EINVAL;
205 imx2_wdt_set_timeout(new_value);
206 imx2_wdt.timeout = new_value;
207 imx2_wdt_ping();
208
209 /* Fallthrough to return current value */
210 case WDIOC_GETTIMEOUT:
211 return put_user(imx2_wdt.timeout, p);
212
213 default:
214 return -ENOTTY;
215 }
216}
217
218static ssize_t imx2_wdt_write(struct file *file, const char __user *data,
219 size_t len, loff_t *ppos)
220{
221 size_t i;
222 char c;
223
224 if (len == 0) /* Can we see this even ? */
225 return 0;
226
227 clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
228 /* scan to see whether or not we got the magic character */
229 for (i = 0; i != len; i++) {
230 if (get_user(c, data + i))
231 return -EFAULT;
232 if (c == 'V')
233 set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
234 }
235
236 imx2_wdt_ping();
237 return len;
238}
239
240static const struct file_operations imx2_wdt_fops = {
241 .owner = THIS_MODULE,
242 .llseek = no_llseek,
243 .unlocked_ioctl = imx2_wdt_ioctl,
244 .open = imx2_wdt_open,
245 .release = imx2_wdt_close,
246 .write = imx2_wdt_write,
247};
248
249static struct miscdevice imx2_wdt_miscdev = {
250 .minor = WATCHDOG_MINOR,
251 .name = "watchdog",
252 .fops = &imx2_wdt_fops,
253};
254
255static int __init imx2_wdt_probe(struct platform_device *pdev)
256{
257 int ret;
258 struct resource *res;
259
260 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
261 if (!res) {
262 dev_err(&pdev->dev, "can't get device resources\n");
263 return -ENODEV;
264 }
265
266 imx2_wdt.base = devm_request_and_ioremap(&pdev->dev, res);
267 if (!imx2_wdt.base) {
268 dev_err(&pdev->dev, "ioremap failed\n");
269 return -ENOMEM;
270 }
271
272 imx2_wdt.clk = clk_get(&pdev->dev, NULL);
273 if (IS_ERR(imx2_wdt.clk)) {
274 dev_err(&pdev->dev, "can't get Watchdog clock\n");
275 return PTR_ERR(imx2_wdt.clk);
276 }
277
278 imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
279 if (imx2_wdt.timeout != timeout)
280 dev_warn(&pdev->dev, "Initial timeout out of range! "
281 "Clamped from %u to %u\n", timeout, imx2_wdt.timeout);
282
283 setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);
284
285 imx2_wdt_miscdev.parent = &pdev->dev;
286 ret = misc_register(&imx2_wdt_miscdev);
287 if (ret)
288 goto fail;
289
290 dev_info(&pdev->dev,
291 "IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
292 imx2_wdt.timeout, nowayout);
293 return 0;
294
295fail:
296 imx2_wdt_miscdev.parent = NULL;
297 clk_put(imx2_wdt.clk);
298 return ret;
299}
300
301static int __exit imx2_wdt_remove(struct platform_device *pdev)
302{
303 misc_deregister(&imx2_wdt_miscdev);
304
305 if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
306 del_timer_sync(&imx2_wdt.timer);
307
308 dev_crit(imx2_wdt_miscdev.parent,
309 "Device removed: Expect reboot!\n");
310 } else
311 clk_put(imx2_wdt.clk);
312
313 imx2_wdt_miscdev.parent = NULL;
314 return 0;
315}
316
317static void imx2_wdt_shutdown(struct platform_device *pdev)
318{
319 if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
320 /* we are running, we need to delete the timer but will give
321 * max timeout before reboot will take place */
322 del_timer_sync(&imx2_wdt.timer);
323 imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
324 imx2_wdt_ping();
325
326 dev_crit(imx2_wdt_miscdev.parent,
327 "Device shutdown: Expect reboot!\n");
328 }
329}
330
331static const struct of_device_id imx2_wdt_dt_ids[] = {
332 { .compatible = "fsl,imx21-wdt", },
333 { /* sentinel */ }
334};
335
336static struct platform_driver imx2_wdt_driver = {
337 .remove = __exit_p(imx2_wdt_remove),
338 .shutdown = imx2_wdt_shutdown,
339 .driver = {
340 .name = DRIVER_NAME,
341 .owner = THIS_MODULE,
342 .of_match_table = imx2_wdt_dt_ids,
343 },
344};
345
346static int __init imx2_wdt_init(void)
347{
348 return platform_driver_probe(&imx2_wdt_driver, imx2_wdt_probe);
349}
350module_init(imx2_wdt_init);
351
352static void __exit imx2_wdt_exit(void)
353{
354 platform_driver_unregister(&imx2_wdt_driver);
355}
356module_exit(imx2_wdt_exit);
357
358MODULE_AUTHOR("Wolfram Sang");
359MODULE_DESCRIPTION("Watchdog driver for IMX2 and later");
360MODULE_LICENSE("GPL v2");
361MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
362MODULE_ALIAS("platform:" DRIVER_NAME);