wm831x_wdt.c (6ad390a25a9d1d8606b9b826878f0a30639dc2b3) wm831x_wdt.c (00411ee9308e4b5f4b04caaa01685f955e259373)
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>
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>
15#include <linux/slab.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
26static int nowayout = WATCHDOG_NOWAYOUT;
27module_param(nowayout, int, 0);
28MODULE_PARM_DESC(nowayout,
29 "Watchdog cannot be stopped once started (default="
30 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
31
16#include <linux/platform_device.h>
17#include <linux/watchdog.h>
18#include <linux/uaccess.h>
19#include <linux/gpio.h>
20
21#include <linux/mfd/wm831x/core.h>
22#include <linux/mfd/wm831x/pdata.h>
23#include <linux/mfd/wm831x/watchdog.h>
24
25static int nowayout = WATCHDOG_NOWAYOUT;
26module_param(nowayout, int, 0);
27MODULE_PARM_DESC(nowayout,
28 "Watchdog cannot be stopped once started (default="
29 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
30
32static unsigned long wm831x_wdt_users;
33static struct miscdevice wm831x_wdt_miscdev;
34static int wm831x_wdt_expect_close;
35static DEFINE_MUTEX(wdt_mutex);
36static struct wm831x *wm831x;
37static unsigned int update_gpio;
38static unsigned int update_state;
31struct wm831x_wdt_drvdata {
32 struct watchdog_device wdt;
33 struct wm831x *wm831x;
34 struct mutex lock;
35 int update_gpio;
36 int update_state;
37};
39
40/* We can't use the sub-second values here but they're included
41 * for completeness. */
42static struct {
38
39/* We can't use the sub-second values here but they're included
40 * for completeness. */
41static struct {
43 int time; /* Seconds */
44 u16 val; /* WDOG_TO value */
42 unsigned int time; /* Seconds */
43 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
44} wm831x_wdt_cfgs[] = {
45 { 1, 2 },
46 { 2, 3 },
47 { 4, 4 },
48 { 8, 5 },
49 { 16, 6 },
50 { 32, 7 },
51 { 33, 7 }, /* Actually 32.768s so include both, others round down */
52};
53
55static int wm831x_wdt_set_timeout(struct wm831x *wm831x, u16 value)
54static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
56{
55{
56 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
57 struct wm831x *wm831x = driver_data->wm831x;
57 int ret;
58
58 int ret;
59
59 mutex_lock(&wdt_mutex);
60 mutex_lock(&driver_data->lock);
60
61 ret = wm831x_reg_unlock(wm831x);
62 if (ret == 0) {
63 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
61
62 ret = wm831x_reg_unlock(wm831x);
63 if (ret == 0) {
64 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
76static 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
65 WM831X_WDOG_ENA, WM831X_WDOG_ENA);
66 wm831x_reg_lock(wm831x);
67 } else {
68 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
69 ret);
70 }
71
92 mutex_unlock(&wdt_mutex);
72 mutex_unlock(&driver_data->lock);
93
94 return ret;
95}
96
73
74 return ret;
75}
76
97static int wm831x_wdt_stop(struct wm831x *wm831x)
77static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
98{
78{
79 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
80 struct wm831x *wm831x = driver_data->wm831x;
99 int ret;
100
81 int ret;
82
101 mutex_lock(&wdt_mutex);
83 mutex_lock(&driver_data->lock);
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
84
85 ret = wm831x_reg_unlock(wm831x);
86 if (ret == 0) {
87 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
88 WM831X_WDOG_ENA, 0);
89 wm831x_reg_lock(wm831x);
90 } else {
91 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
92 ret);
93 }
94
113 mutex_unlock(&wdt_mutex);
95 mutex_unlock(&driver_data->lock);
114
115 return ret;
116}
117
96
97 return ret;
98}
99
118static int wm831x_wdt_kick(struct wm831x *wm831x)
100static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
119{
101{
102 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
103 struct wm831x *wm831x = driver_data->wm831x;
120 int ret;
121 u16 reg;
122
104 int ret;
105 u16 reg;
106
123 mutex_lock(&wdt_mutex);
107 mutex_lock(&driver_data->lock);
124
108
125 if (update_gpio) {
126 gpio_set_value_cansleep(update_gpio, update_state);
127 update_state = !update_state;
109 if (driver_data->update_gpio) {
110 gpio_set_value_cansleep(driver_data->update_gpio,
111 driver_data->update_state);
112 driver_data->update_state = !driver_data->update_state;
128 ret = 0;
129 goto out;
130 }
131
113 ret = 0;
114 goto out;
115 }
116
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

--- 4 unchanged lines hidden (view full) ---

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
152out:
117 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
118
119 if (!(reg & WM831X_WDOG_RST_SRC)) {
120 dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
121 ret = -EINVAL;
122 goto out;
123 }
124

--- 4 unchanged lines hidden (view full) ---

129 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
130 wm831x_reg_lock(wm831x);
131 } else {
132 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
133 ret);
134 }
135
136out:
153 mutex_unlock(&wdt_mutex);
137 mutex_unlock(&driver_data->lock);
154
155 return ret;
156}
157
138
139 return ret;
140}
141
158static int wm831x_wdt_open(struct inode *inode, struct file *file)
142static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
143 unsigned int timeout)
159{
144{
160 int ret;
145 struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
146 struct wm831x *wm831x = driver_data->wm831x;
147 int ret, i;
161
148
162 if (!wm831x)
163 return -ENODEV;
149 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
150 if (wm831x_wdt_cfgs[i].time == timeout)
151 break;
152 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
153 ret = -EINVAL;
164
154
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
175static 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);
155 ret = wm831x_reg_unlock(wm831x);
156 if (ret == 0) {
157 ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
158 WM831X_WDOG_TO_MASK,
159 wm831x_wdt_cfgs[i].val);
160 wm831x_reg_lock(wm831x);
161 } else {
162 dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
163 ret);
182 }
183
164 }
165
184 clear_bit(0, &wm831x_wdt_users);
185
186 return 0;
166 return ret;
187}
188
167}
168
189static 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
216static const struct watchdog_info ident = {
169static const struct watchdog_info wm831x_wdt_info = {
217 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
218 .identity = "WM831x Watchdog",
219};
220
170 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
171 .identity = "WM831x Watchdog",
172};
173
221static 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
302static const struct file_operations wm831x_wdt_fops = {
174static const struct watchdog_ops wm831x_wdt_ops = {
303 .owner = THIS_MODULE,
175 .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,
176 .start = wm831x_wdt_start,
177 .stop = wm831x_wdt_stop,
178 .ping = wm831x_wdt_ping,
179 .set_timeout = wm831x_wdt_set_timeout,
309};
310
180};
181
311static struct miscdevice wm831x_wdt_miscdev = {
312 .minor = WATCHDOG_MINOR,
313 .name = "watchdog",
314 .fops = &wm831x_wdt_fops,
315};
316
317static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
318{
182static int __devinit wm831x_wdt_probe(struct platform_device *pdev)
183{
184 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
319 struct wm831x_pdata *chip_pdata;
320 struct wm831x_watchdog_pdata *pdata;
185 struct wm831x_pdata *chip_pdata;
186 struct wm831x_watchdog_pdata *pdata;
321 int reg, ret;
187 struct wm831x_wdt_drvdata *driver_data;
188 struct watchdog_device *wm831x_wdt;
189 int reg, ret, i;
322
190
323 if (wm831x) {
324 dev_err(&pdev->dev, "wm831x watchdog already registered\n");
325 return -EBUSY;
326 }
327
328 wm831x = dev_get_drvdata(pdev->dev.parent);
329
330 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
331 if (ret < 0) {
332 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
333 ret);
334 goto err;
335 }
336 reg = ret;
337
338 if (reg & WM831X_WDOG_DEBUG)
339 dev_warn(wm831x->dev, "Watchdog is paused\n");
340
191 ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
192 if (ret < 0) {
193 dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
194 ret);
195 goto err;
196 }
197 reg = ret;
198
199 if (reg & WM831X_WDOG_DEBUG)
200 dev_warn(wm831x->dev, "Watchdog is paused\n");
201
202 driver_data = kzalloc(sizeof(*driver_data), GFP_KERNEL);
203 if (!driver_data) {
204 dev_err(wm831x->dev, "Unable to alloacate watchdog device\n");
205 ret = -ENOMEM;
206 goto err;
207 }
208
209 mutex_init(&driver_data->lock);
210 driver_data->wm831x = wm831x;
211
212 wm831x_wdt = &driver_data->wdt;
213
214 wm831x_wdt->info = &wm831x_wdt_info;
215 wm831x_wdt->ops = &wm831x_wdt_ops;
216 watchdog_set_drvdata(wm831x_wdt, driver_data);
217
218 if (nowayout)
219 wm831x_wdt->status |= WDOG_NO_WAY_OUT;
220
221 reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
222 reg &= WM831X_WDOG_TO_MASK;
223 for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
224 if (wm831x_wdt_cfgs[i].val == reg)
225 break;
226 if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
227 dev_warn(wm831x->dev,
228 "Unknown watchdog timeout: %x\n", reg);
229 else
230 wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
231
341 /* Apply any configuration */
342 if (pdev->dev.parent->platform_data) {
343 chip_pdata = pdev->dev.parent->platform_data;
344 pdata = chip_pdata->watchdog;
345 } else {
346 pdata = NULL;
347 }
348

--- 7 unchanged lines hidden (view full) ---

356
357 if (pdata->update_gpio) {
358 ret = gpio_request(pdata->update_gpio,
359 "Watchdog update");
360 if (ret < 0) {
361 dev_err(wm831x->dev,
362 "Failed to request update GPIO: %d\n",
363 ret);
232 /* Apply any configuration */
233 if (pdev->dev.parent->platform_data) {
234 chip_pdata = pdev->dev.parent->platform_data;
235 pdata = chip_pdata->watchdog;
236 } else {
237 pdata = NULL;
238 }
239

--- 7 unchanged lines hidden (view full) ---

247
248 if (pdata->update_gpio) {
249 ret = gpio_request(pdata->update_gpio,
250 "Watchdog update");
251 if (ret < 0) {
252 dev_err(wm831x->dev,
253 "Failed to request update GPIO: %d\n",
254 ret);
364 goto err;
255 goto err_alloc;
365 }
366
367 ret = gpio_direction_output(pdata->update_gpio, 0);
368 if (ret != 0) {
369 dev_err(wm831x->dev,
370 "gpio_direction_output returned: %d\n",
371 ret);
372 goto err_gpio;
373 }
374
256 }
257
258 ret = gpio_direction_output(pdata->update_gpio, 0);
259 if (ret != 0) {
260 dev_err(wm831x->dev,
261 "gpio_direction_output returned: %d\n",
262 ret);
263 goto err_gpio;
264 }
265
375 update_gpio = pdata->update_gpio;
266 driver_data->update_gpio = pdata->update_gpio;
376
377 /* Make sure the watchdog takes hardware updates */
378 reg |= WM831X_WDOG_RST_SRC;
379 }
380
381 ret = wm831x_reg_unlock(wm831x);
382 if (ret == 0) {
383 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
384 wm831x_reg_lock(wm831x);
385 } else {
386 dev_err(wm831x->dev,
387 "Failed to unlock security key: %d\n", ret);
388 goto err_gpio;
389 }
390 }
391
267
268 /* Make sure the watchdog takes hardware updates */
269 reg |= WM831X_WDOG_RST_SRC;
270 }
271
272 ret = wm831x_reg_unlock(wm831x);
273 if (ret == 0) {
274 ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
275 wm831x_reg_lock(wm831x);
276 } else {
277 dev_err(wm831x->dev,
278 "Failed to unlock security key: %d\n", ret);
279 goto err_gpio;
280 }
281 }
282
392 wm831x_wdt_miscdev.parent = &pdev->dev;
393
394 ret = misc_register(&wm831x_wdt_miscdev);
283 ret = watchdog_register_device(&driver_data->wdt);
395 if (ret != 0) {
284 if (ret != 0) {
396 dev_err(wm831x->dev, "Failed to register miscdev: %d\n", ret);
285 dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
286 ret);
397 goto err_gpio;
398 }
399
287 goto err_gpio;
288 }
289
290 dev_set_drvdata(&pdev->dev, driver_data);
291
400 return 0;
401
402err_gpio:
292 return 0;
293
294err_gpio:
403 if (update_gpio) {
404 gpio_free(update_gpio);
405 update_gpio = 0;
406 }
295 if (driver_data->update_gpio)
296 gpio_free(driver_data->update_gpio);
297err_alloc:
298 kfree(driver_data);
407err:
408 return ret;
409}
410
411static int __devexit wm831x_wdt_remove(struct platform_device *pdev)
412{
299err:
300 return ret;
301}
302
303static int __devexit wm831x_wdt_remove(struct platform_device *pdev)
304{
413 if (update_gpio) {
414 gpio_free(update_gpio);
415 update_gpio = 0;
416 }
305 struct wm831x_wdt_drvdata *driver_data = dev_get_drvdata(&pdev->dev);
417
306
418 misc_deregister(&wm831x_wdt_miscdev);
307 watchdog_unregister_device(&driver_data->wdt);
419
308
309 if (driver_data->update_gpio)
310 gpio_free(driver_data->update_gpio);
311
420 return 0;
421}
422
423static struct platform_driver wm831x_wdt_driver = {
424 .probe = wm831x_wdt_probe,
425 .remove = __devexit_p(wm831x_wdt_remove),
426 .driver = {
427 .name = "wm831x-watchdog",

--- 19 unchanged lines hidden --- 		312 return 0;
313}
314
315static struct platform_driver wm831x_wdt_driver = {
316 .probe = wm831x_wdt_probe,
317 .remove = __devexit_p(wm831x_wdt_remove),
318 .driver = {
319 .name = "wm831x-watchdog",

--- 19 unchanged lines hidden ---