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1 | /* |
2 | * Kontron PLD watchdog driver | |
3 | * | |
4 | * Copyright (c) 2010-2013 Kontron Europe GmbH | |
5 | * Author: Michael Brunner <michael.brunner@kontron.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License 2 as published | |
9 | * by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * Note: From the PLD watchdog point of view timeout and pretimeout are | |
17 | * defined differently than in the kernel. | |
18 | * First the pretimeout stage runs out before the timeout stage gets | |
19 | * active. | |
20 | * | |
21 | * Kernel/API: P-----| pretimeout | |
22 | * |-----------------------T timeout | |
23 | * Watchdog: |-----------------P pretimeout_stage | |
24 | * |-----T timeout_stage | |
25 | */ | |
26 | ||
27 | #include <linux/module.h> | |
28 | #include <linux/moduleparam.h> | |
29 | #include <linux/miscdevice.h> | |
30 | #include <linux/uaccess.h> | |
31 | #include <linux/watchdog.h> | |
32 | #include <linux/platform_device.h> | |
33 | #include <linux/mfd/kempld.h> | |
34 | ||
35 | #define KEMPLD_WDT_STAGE_TIMEOUT(x) (0x1b + (x) * 4) | |
36 | #define KEMPLD_WDT_STAGE_CFG(x) (0x18 + (x)) | |
37 | #define STAGE_CFG_GET_PRESCALER(x) (((x) & 0x30) >> 4) | |
38 | #define STAGE_CFG_SET_PRESCALER(x) (((x) & 0x30) << 4) | |
39 | #define STAGE_CFG_PRESCALER_MASK 0x30 | |
40 | #define STAGE_CFG_ACTION_MASK 0x7 | |
41 | #define STAGE_CFG_ASSERT (1 << 3) | |
42 | ||
43 | #define KEMPLD_WDT_MAX_STAGES 2 | |
44 | #define KEMPLD_WDT_KICK 0x16 | |
45 | #define KEMPLD_WDT_CFG 0x17 | |
46 | #define KEMPLD_WDT_CFG_ENABLE 0x10 | |
47 | #define KEMPLD_WDT_CFG_ENABLE_LOCK 0x8 | |
48 | #define KEMPLD_WDT_CFG_GLOBAL_LOCK 0x80 | |
49 | ||
50 | enum { | |
51 | ACTION_NONE = 0, | |
52 | ACTION_RESET, | |
53 | ACTION_NMI, | |
54 | ACTION_SMI, | |
55 | ACTION_SCI, | |
56 | ACTION_DELAY, | |
57 | }; | |
58 | ||
59 | enum { | |
60 | STAGE_TIMEOUT = 0, | |
61 | STAGE_PRETIMEOUT, | |
62 | }; | |
63 | ||
64 | enum { | |
65 | PRESCALER_21 = 0, | |
66 | PRESCALER_17, | |
67 | PRESCALER_12, | |
68 | }; | |
69 | ||
70 | const u32 kempld_prescaler[] = { | |
71 | [PRESCALER_21] = (1 << 21) - 1, | |
72 | [PRESCALER_17] = (1 << 17) - 1, | |
73 | [PRESCALER_12] = (1 << 12) - 1, | |
74 | 0, | |
75 | }; | |
76 | ||
77 | struct kempld_wdt_stage { | |
78 | unsigned int id; | |
79 | u32 mask; | |
80 | }; | |
81 | ||
82 | struct kempld_wdt_data { | |
83 | struct kempld_device_data *pld; | |
84 | struct watchdog_device wdd; | |
85 | unsigned int pretimeout; | |
86 | struct kempld_wdt_stage stage[KEMPLD_WDT_MAX_STAGES]; | |
87 | #ifdef CONFIG_PM | |
88 | u8 pm_status_store; | |
89 | #endif | |
90 | }; | |
91 | ||
92 | #define DEFAULT_TIMEOUT 30 /* seconds */ | |
93 | #define DEFAULT_PRETIMEOUT 0 | |
94 | ||
95 | static unsigned int timeout = DEFAULT_TIMEOUT; | |
96 | module_param(timeout, uint, 0); | |
97 | MODULE_PARM_DESC(timeout, | |
98 | "Watchdog timeout in seconds. (>=0, default=" | |
99 | __MODULE_STRING(DEFAULT_TIMEOUT) ")"); | |
100 | ||
101 | static unsigned int pretimeout = DEFAULT_PRETIMEOUT; | |
102 | module_param(pretimeout, uint, 0); | |
103 | MODULE_PARM_DESC(pretimeout, | |
104 | "Watchdog pretimeout in seconds. (>=0, default=" | |
105 | __MODULE_STRING(DEFAULT_PRETIMEOUT) ")"); | |
106 | ||
107 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
108 | module_param(nowayout, bool, 0); | |
109 | MODULE_PARM_DESC(nowayout, | |
110 | "Watchdog cannot be stopped once started (default=" | |
111 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
112 | ||
113 | static int kempld_wdt_set_stage_action(struct kempld_wdt_data *wdt_data, | |
114 | struct kempld_wdt_stage *stage, | |
115 | u8 action) | |
116 | { | |
117 | struct kempld_device_data *pld = wdt_data->pld; | |
118 | u8 stage_cfg; | |
119 | ||
120 | if (!stage || !stage->mask) | |
121 | return -EINVAL; | |
122 | ||
123 | kempld_get_mutex(pld); | |
124 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); | |
125 | stage_cfg &= ~STAGE_CFG_ACTION_MASK; | |
126 | stage_cfg |= (action & STAGE_CFG_ACTION_MASK); | |
127 | ||
128 | if (action == ACTION_RESET) | |
129 | stage_cfg |= STAGE_CFG_ASSERT; | |
130 | else | |
131 | stage_cfg &= ~STAGE_CFG_ASSERT; | |
132 | ||
133 | kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg); | |
134 | kempld_release_mutex(pld); | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static int kempld_wdt_set_stage_timeout(struct kempld_wdt_data *wdt_data, | |
140 | struct kempld_wdt_stage *stage, | |
141 | unsigned int timeout) | |
142 | { | |
143 | struct kempld_device_data *pld = wdt_data->pld; | |
144 | u32 prescaler = kempld_prescaler[PRESCALER_21]; | |
145 | u64 stage_timeout64; | |
146 | u32 stage_timeout; | |
147 | u32 remainder; | |
148 | u8 stage_cfg; | |
149 | ||
150 | if (!stage) | |
151 | return -EINVAL; | |
152 | ||
153 | stage_timeout64 = (u64)timeout * pld->pld_clock; | |
154 | remainder = do_div(stage_timeout64, prescaler); | |
155 | if (remainder) | |
156 | stage_timeout64++; | |
157 | ||
158 | if (stage_timeout64 > stage->mask) | |
159 | return -EINVAL; | |
160 | ||
161 | stage_timeout = stage_timeout64 & stage->mask; | |
162 | ||
163 | kempld_get_mutex(pld); | |
164 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); | |
165 | stage_cfg &= ~STAGE_CFG_PRESCALER_MASK; | |
166 | stage_cfg |= STAGE_CFG_SET_PRESCALER(prescaler); | |
167 | kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg); | |
168 | kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id), | |
169 | stage_timeout); | |
170 | kempld_release_mutex(pld); | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
175 | /* | |
176 | * kempld_get_mutex must be called prior to calling this function. | |
177 | */ | |
178 | static unsigned int kempld_wdt_get_timeout(struct kempld_wdt_data *wdt_data, | |
179 | struct kempld_wdt_stage *stage) | |
180 | { | |
181 | struct kempld_device_data *pld = wdt_data->pld; | |
182 | unsigned int timeout; | |
183 | u64 stage_timeout; | |
184 | u32 prescaler; | |
185 | u32 remainder; | |
186 | u8 stage_cfg; | |
187 | ||
188 | if (!stage->mask) | |
189 | return 0; | |
190 | ||
191 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); | |
192 | stage_timeout = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id)); | |
193 | prescaler = kempld_prescaler[STAGE_CFG_GET_PRESCALER(stage_cfg)]; | |
194 | ||
195 | stage_timeout = (stage_timeout & stage->mask) * prescaler; | |
196 | remainder = do_div(stage_timeout, pld->pld_clock); | |
197 | if (remainder) | |
198 | stage_timeout++; | |
199 | ||
200 | timeout = stage_timeout; | |
201 | WARN_ON_ONCE(timeout != stage_timeout); | |
202 | ||
203 | return timeout; | |
204 | } | |
205 | ||
206 | static int kempld_wdt_set_timeout(struct watchdog_device *wdd, | |
207 | unsigned int timeout) | |
208 | { | |
209 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
210 | struct kempld_wdt_stage *pretimeout_stage; | |
211 | struct kempld_wdt_stage *timeout_stage; | |
212 | int ret; | |
213 | ||
214 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; | |
215 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
216 | ||
217 | if (pretimeout_stage->mask && wdt_data->pretimeout > 0) | |
218 | timeout = wdt_data->pretimeout; | |
219 | ||
220 | ret = kempld_wdt_set_stage_action(wdt_data, timeout_stage, | |
221 | ACTION_RESET); | |
222 | if (ret) | |
223 | return ret; | |
224 | ret = kempld_wdt_set_stage_timeout(wdt_data, timeout_stage, | |
225 | timeout); | |
226 | if (ret) | |
227 | return ret; | |
228 | ||
229 | wdd->timeout = timeout; | |
230 | return 0; | |
231 | } | |
232 | ||
233 | static int kempld_wdt_set_pretimeout(struct watchdog_device *wdd, | |
234 | unsigned int pretimeout) | |
235 | { | |
236 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
237 | struct kempld_wdt_stage *pretimeout_stage; | |
238 | u8 action = ACTION_NONE; | |
239 | int ret; | |
240 | ||
241 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
242 | ||
243 | if (!pretimeout_stage->mask) | |
244 | return -ENXIO; | |
245 | ||
246 | if (pretimeout > wdd->timeout) | |
247 | return -EINVAL; | |
248 | ||
249 | if (pretimeout > 0) | |
250 | action = ACTION_NMI; | |
251 | ||
252 | ret = kempld_wdt_set_stage_action(wdt_data, pretimeout_stage, | |
253 | action); | |
254 | if (ret) | |
255 | return ret; | |
256 | ret = kempld_wdt_set_stage_timeout(wdt_data, pretimeout_stage, | |
257 | wdd->timeout - pretimeout); | |
258 | if (ret) | |
259 | return ret; | |
260 | ||
261 | wdt_data->pretimeout = pretimeout; | |
262 | return 0; | |
263 | } | |
264 | ||
265 | static void kempld_wdt_update_timeouts(struct kempld_wdt_data *wdt_data) | |
266 | { | |
267 | struct kempld_device_data *pld = wdt_data->pld; | |
268 | struct kempld_wdt_stage *pretimeout_stage; | |
269 | struct kempld_wdt_stage *timeout_stage; | |
270 | unsigned int pretimeout, timeout; | |
271 | ||
272 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
273 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; | |
274 | ||
275 | kempld_get_mutex(pld); | |
276 | pretimeout = kempld_wdt_get_timeout(wdt_data, pretimeout_stage); | |
277 | timeout = kempld_wdt_get_timeout(wdt_data, timeout_stage); | |
278 | kempld_release_mutex(pld); | |
279 | ||
280 | if (pretimeout) | |
281 | wdt_data->pretimeout = timeout; | |
282 | else | |
283 | wdt_data->pretimeout = 0; | |
284 | ||
285 | wdt_data->wdd.timeout = pretimeout + timeout; | |
286 | } | |
287 | ||
288 | static int kempld_wdt_start(struct watchdog_device *wdd) | |
289 | { | |
290 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
291 | struct kempld_device_data *pld = wdt_data->pld; | |
292 | u8 status; | |
293 | int ret; | |
294 | ||
295 | ret = kempld_wdt_set_timeout(wdd, wdd->timeout); | |
296 | if (ret) | |
297 | return ret; | |
298 | ||
299 | kempld_get_mutex(pld); | |
300 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
301 | status |= KEMPLD_WDT_CFG_ENABLE; | |
302 | kempld_write8(pld, KEMPLD_WDT_CFG, status); | |
303 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
304 | kempld_release_mutex(pld); | |
305 | ||
306 | /* Check if the watchdog was enabled */ | |
307 | if (!(status & KEMPLD_WDT_CFG_ENABLE)) | |
308 | return -EACCES; | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | static int kempld_wdt_stop(struct watchdog_device *wdd) | |
314 | { | |
315 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
316 | struct kempld_device_data *pld = wdt_data->pld; | |
317 | u8 status; | |
318 | ||
319 | kempld_get_mutex(pld); | |
320 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
321 | status &= ~KEMPLD_WDT_CFG_ENABLE; | |
322 | kempld_write8(pld, KEMPLD_WDT_CFG, status); | |
323 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
324 | kempld_release_mutex(pld); | |
325 | ||
326 | /* Check if the watchdog was disabled */ | |
327 | if (status & KEMPLD_WDT_CFG_ENABLE) | |
328 | return -EACCES; | |
329 | ||
330 | return 0; | |
331 | } | |
332 | ||
333 | static int kempld_wdt_keepalive(struct watchdog_device *wdd) | |
334 | { | |
335 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
336 | struct kempld_device_data *pld = wdt_data->pld; | |
337 | ||
338 | kempld_get_mutex(pld); | |
339 | kempld_write8(pld, KEMPLD_WDT_KICK, 'K'); | |
340 | kempld_release_mutex(pld); | |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | static long kempld_wdt_ioctl(struct watchdog_device *wdd, unsigned int cmd, | |
346 | unsigned long arg) | |
347 | { | |
348 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
349 | void __user *argp = (void __user *)arg; | |
350 | int ret = -ENOIOCTLCMD; | |
351 | int __user *p = argp; | |
352 | int new_value; | |
353 | ||
354 | switch (cmd) { | |
355 | case WDIOC_SETPRETIMEOUT: | |
356 | if (get_user(new_value, p)) | |
357 | return -EFAULT; | |
358 | ret = kempld_wdt_set_pretimeout(wdd, new_value); | |
359 | if (ret) | |
360 | return ret; | |
361 | ret = kempld_wdt_keepalive(wdd); | |
362 | break; | |
363 | case WDIOC_GETPRETIMEOUT: | |
364 | ret = put_user(wdt_data->pretimeout, (int *)arg); | |
365 | break; | |
366 | } | |
367 | ||
368 | return ret; | |
369 | } | |
370 | ||
371 | static int kempld_wdt_probe_stages(struct watchdog_device *wdd) | |
372 | { | |
373 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
374 | struct kempld_device_data *pld = wdt_data->pld; | |
375 | struct kempld_wdt_stage *pretimeout_stage; | |
376 | struct kempld_wdt_stage *timeout_stage; | |
377 | u8 index, data, data_orig; | |
378 | u32 mask; | |
379 | int i, j; | |
380 | ||
381 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
382 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; | |
383 | ||
384 | pretimeout_stage->mask = 0; | |
385 | timeout_stage->mask = 0; | |
386 | ||
387 | for (i = 0; i < 3; i++) { | |
388 | index = KEMPLD_WDT_STAGE_TIMEOUT(i); | |
389 | mask = 0; | |
390 | ||
391 | kempld_get_mutex(pld); | |
392 | /* Probe each byte individually. */ | |
393 | for (j = 0; j < 4; j++) { | |
394 | data_orig = kempld_read8(pld, index + j); | |
395 | kempld_write8(pld, index + j, 0x00); | |
396 | data = kempld_read8(pld, index + j); | |
397 | /* A failed write means this byte is reserved */ | |
398 | if (data != 0x00) | |
399 | break; | |
400 | kempld_write8(pld, index + j, data_orig); | |
401 | mask |= 0xff << (j * 8); | |
402 | } | |
403 | kempld_release_mutex(pld); | |
404 | ||
405 | /* Assign available stages to timeout and pretimeout */ | |
406 | if (!timeout_stage->mask) { | |
407 | timeout_stage->mask = mask; | |
408 | timeout_stage->id = i; | |
409 | } else { | |
410 | if (pld->feature_mask & KEMPLD_FEATURE_BIT_NMI) { | |
411 | pretimeout_stage->mask = timeout_stage->mask; | |
412 | timeout_stage->mask = mask; | |
413 | pretimeout_stage->id = timeout_stage->id; | |
414 | timeout_stage->id = i; | |
415 | } | |
416 | break; | |
417 | } | |
418 | } | |
419 | ||
420 | if (!timeout_stage->mask) | |
421 | return -ENODEV; | |
422 | ||
423 | return 0; | |
424 | } | |
425 | ||
426 | static struct watchdog_info kempld_wdt_info = { | |
427 | .identity = "KEMPLD Watchdog", | |
428 | .options = WDIOF_SETTIMEOUT | | |
429 | WDIOF_KEEPALIVEPING | | |
430 | WDIOF_MAGICCLOSE | | |
431 | WDIOF_PRETIMEOUT | |
432 | }; | |
433 | ||
434 | static struct watchdog_ops kempld_wdt_ops = { | |
435 | .owner = THIS_MODULE, | |
436 | .start = kempld_wdt_start, | |
437 | .stop = kempld_wdt_stop, | |
438 | .ping = kempld_wdt_keepalive, | |
439 | .set_timeout = kempld_wdt_set_timeout, | |
440 | .ioctl = kempld_wdt_ioctl, | |
441 | }; | |
442 | ||
443 | static int kempld_wdt_probe(struct platform_device *pdev) | |
444 | { | |
445 | struct kempld_device_data *pld = dev_get_drvdata(pdev->dev.parent); | |
446 | struct kempld_wdt_data *wdt_data; | |
447 | struct device *dev = &pdev->dev; | |
448 | struct watchdog_device *wdd; | |
449 | u8 status; | |
450 | int ret = 0; | |
451 | ||
452 | wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL); | |
453 | if (!wdt_data) | |
454 | return -ENOMEM; | |
455 | ||
456 | wdt_data->pld = pld; | |
457 | wdd = &wdt_data->wdd; | |
458 | wdd->parent = dev; | |
459 | ||
460 | kempld_get_mutex(pld); | |
461 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
462 | kempld_release_mutex(pld); | |
463 | ||
464 | /* Enable nowayout if watchdog is already locked */ | |
465 | if (status & (KEMPLD_WDT_CFG_ENABLE_LOCK | | |
466 | KEMPLD_WDT_CFG_GLOBAL_LOCK)) { | |
467 | if (!nowayout) | |
468 | dev_warn(dev, | |
469 | "Forcing nowayout - watchdog lock enabled!\n"); | |
470 | nowayout = true; | |
471 | } | |
472 | ||
473 | wdd->info = &kempld_wdt_info; | |
474 | wdd->ops = &kempld_wdt_ops; | |
475 | ||
476 | watchdog_set_drvdata(wdd, wdt_data); | |
477 | watchdog_set_nowayout(wdd, nowayout); | |
478 | ||
479 | ret = kempld_wdt_probe_stages(wdd); | |
480 | if (ret) | |
481 | return ret; | |
482 | ||
483 | kempld_wdt_set_timeout(wdd, timeout); | |
484 | kempld_wdt_set_pretimeout(wdd, pretimeout); | |
485 | ||
486 | /* Check if watchdog is already enabled */ | |
487 | if (status & KEMPLD_WDT_CFG_ENABLE) { | |
488 | /* Get current watchdog settings */ | |
489 | kempld_wdt_update_timeouts(wdt_data); | |
490 | dev_info(dev, "Watchdog was already enabled\n"); | |
491 | } | |
492 | ||
493 | platform_set_drvdata(pdev, wdt_data); | |
494 | ret = watchdog_register_device(wdd); | |
495 | if (ret) | |
496 | return ret; | |
497 | ||
498 | dev_info(dev, "Watchdog registered with %ds timeout\n", wdd->timeout); | |
499 | ||
500 | return 0; | |
501 | } | |
502 | ||
503 | static void kempld_wdt_shutdown(struct platform_device *pdev) | |
504 | { | |
505 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
506 | ||
507 | kempld_wdt_stop(&wdt_data->wdd); | |
508 | } | |
509 | ||
510 | static int kempld_wdt_remove(struct platform_device *pdev) | |
511 | { | |
512 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
513 | struct watchdog_device *wdd = &wdt_data->wdd; | |
514 | int ret = 0; | |
515 | ||
516 | if (!nowayout) | |
517 | ret = kempld_wdt_stop(wdd); | |
518 | watchdog_unregister_device(wdd); | |
519 | ||
520 | return ret; | |
521 | } | |
522 | ||
523 | #ifdef CONFIG_PM | |
524 | /* Disable watchdog if it is active during suspend */ | |
525 | static int kempld_wdt_suspend(struct platform_device *pdev, | |
526 | pm_message_t message) | |
527 | { | |
528 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
529 | struct kempld_device_data *pld = wdt_data->pld; | |
530 | struct watchdog_device *wdd = &wdt_data->wdd; | |
531 | ||
532 | kempld_get_mutex(pld); | |
533 | wdt_data->pm_status_store = kempld_read8(pld, KEMPLD_WDT_CFG); | |
534 | kempld_release_mutex(pld); | |
535 | ||
536 | kempld_wdt_update_timeouts(wdt_data); | |
537 | ||
538 | if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE) | |
539 | return kempld_wdt_stop(wdd); | |
540 | ||
541 | return 0; | |
542 | } | |
543 | ||
544 | /* Enable watchdog and configure it if necessary */ | |
545 | static int kempld_wdt_resume(struct platform_device *pdev) | |
546 | { | |
547 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
548 | struct watchdog_device *wdd = &wdt_data->wdd; | |
549 | ||
550 | /* | |
551 | * If watchdog was stopped before suspend be sure it gets disabled | |
552 | * again, for the case BIOS has enabled it during resume | |
553 | */ | |
554 | if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE) | |
555 | return kempld_wdt_start(wdd); | |
556 | else | |
557 | return kempld_wdt_stop(wdd); | |
558 | } | |
559 | #else | |
560 | #define kempld_wdt_suspend NULL | |
561 | #define kempld_wdt_resume NULL | |
562 | #endif | |
563 | ||
564 | static struct platform_driver kempld_wdt_driver = { | |
565 | .driver = { | |
566 | .name = "kempld-wdt", | |
567 | .owner = THIS_MODULE, | |
568 | }, | |
569 | .probe = kempld_wdt_probe, | |
570 | .remove = kempld_wdt_remove, | |
571 | .shutdown = kempld_wdt_shutdown, | |
572 | .suspend = kempld_wdt_suspend, | |
573 | .resume = kempld_wdt_resume, | |
574 | }; | |
575 | ||
576 | module_platform_driver(kempld_wdt_driver); | |
577 | ||
578 | MODULE_DESCRIPTION("KEM PLD Watchdog Driver"); | |
579 | MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>"); | |
580 | MODULE_LICENSE("GPL"); | |
581 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |