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e51c288e KS |
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> | |
e51c288e KS |
29 | #include <linux/uaccess.h> |
30 | #include <linux/watchdog.h> | |
31 | #include <linux/platform_device.h> | |
32 | #include <linux/mfd/kempld.h> | |
33 | ||
34 | #define KEMPLD_WDT_STAGE_TIMEOUT(x) (0x1b + (x) * 4) | |
35 | #define KEMPLD_WDT_STAGE_CFG(x) (0x18 + (x)) | |
36 | #define STAGE_CFG_GET_PRESCALER(x) (((x) & 0x30) >> 4) | |
4c4e4566 | 37 | #define STAGE_CFG_SET_PRESCALER(x) (((x) & 0x3) << 4) |
e51c288e KS |
38 | #define STAGE_CFG_PRESCALER_MASK 0x30 |
39 | #define STAGE_CFG_ACTION_MASK 0x7 | |
40 | #define STAGE_CFG_ASSERT (1 << 3) | |
41 | ||
42 | #define KEMPLD_WDT_MAX_STAGES 2 | |
43 | #define KEMPLD_WDT_KICK 0x16 | |
44 | #define KEMPLD_WDT_CFG 0x17 | |
45 | #define KEMPLD_WDT_CFG_ENABLE 0x10 | |
46 | #define KEMPLD_WDT_CFG_ENABLE_LOCK 0x8 | |
47 | #define KEMPLD_WDT_CFG_GLOBAL_LOCK 0x80 | |
48 | ||
49 | enum { | |
50 | ACTION_NONE = 0, | |
51 | ACTION_RESET, | |
52 | ACTION_NMI, | |
53 | ACTION_SMI, | |
54 | ACTION_SCI, | |
55 | ACTION_DELAY, | |
56 | }; | |
57 | ||
58 | enum { | |
59 | STAGE_TIMEOUT = 0, | |
60 | STAGE_PRETIMEOUT, | |
61 | }; | |
62 | ||
63 | enum { | |
64 | PRESCALER_21 = 0, | |
65 | PRESCALER_17, | |
66 | PRESCALER_12, | |
67 | }; | |
68 | ||
b3970bde | 69 | static const u32 kempld_prescaler[] = { |
e51c288e KS |
70 | [PRESCALER_21] = (1 << 21) - 1, |
71 | [PRESCALER_17] = (1 << 17) - 1, | |
72 | [PRESCALER_12] = (1 << 12) - 1, | |
73 | 0, | |
74 | }; | |
75 | ||
76 | struct kempld_wdt_stage { | |
77 | unsigned int id; | |
78 | u32 mask; | |
79 | }; | |
80 | ||
81 | struct kempld_wdt_data { | |
82 | struct kempld_device_data *pld; | |
83 | struct watchdog_device wdd; | |
84 | unsigned int pretimeout; | |
85 | struct kempld_wdt_stage stage[KEMPLD_WDT_MAX_STAGES]; | |
86 | #ifdef CONFIG_PM | |
87 | u8 pm_status_store; | |
88 | #endif | |
89 | }; | |
90 | ||
91 | #define DEFAULT_TIMEOUT 30 /* seconds */ | |
92 | #define DEFAULT_PRETIMEOUT 0 | |
93 | ||
94 | static unsigned int timeout = DEFAULT_TIMEOUT; | |
95 | module_param(timeout, uint, 0); | |
96 | MODULE_PARM_DESC(timeout, | |
97 | "Watchdog timeout in seconds. (>=0, default=" | |
98 | __MODULE_STRING(DEFAULT_TIMEOUT) ")"); | |
99 | ||
100 | static unsigned int pretimeout = DEFAULT_PRETIMEOUT; | |
101 | module_param(pretimeout, uint, 0); | |
102 | MODULE_PARM_DESC(pretimeout, | |
103 | "Watchdog pretimeout in seconds. (>=0, default=" | |
104 | __MODULE_STRING(DEFAULT_PRETIMEOUT) ")"); | |
105 | ||
106 | static bool nowayout = WATCHDOG_NOWAYOUT; | |
107 | module_param(nowayout, bool, 0); | |
108 | MODULE_PARM_DESC(nowayout, | |
109 | "Watchdog cannot be stopped once started (default=" | |
110 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
111 | ||
112 | static int kempld_wdt_set_stage_action(struct kempld_wdt_data *wdt_data, | |
113 | struct kempld_wdt_stage *stage, | |
114 | u8 action) | |
115 | { | |
116 | struct kempld_device_data *pld = wdt_data->pld; | |
117 | u8 stage_cfg; | |
118 | ||
119 | if (!stage || !stage->mask) | |
120 | return -EINVAL; | |
121 | ||
122 | kempld_get_mutex(pld); | |
123 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); | |
124 | stage_cfg &= ~STAGE_CFG_ACTION_MASK; | |
125 | stage_cfg |= (action & STAGE_CFG_ACTION_MASK); | |
126 | ||
127 | if (action == ACTION_RESET) | |
128 | stage_cfg |= STAGE_CFG_ASSERT; | |
129 | else | |
130 | stage_cfg &= ~STAGE_CFG_ASSERT; | |
131 | ||
132 | kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg); | |
133 | kempld_release_mutex(pld); | |
134 | ||
135 | return 0; | |
136 | } | |
137 | ||
138 | static int kempld_wdt_set_stage_timeout(struct kempld_wdt_data *wdt_data, | |
139 | struct kempld_wdt_stage *stage, | |
140 | unsigned int timeout) | |
141 | { | |
142 | struct kempld_device_data *pld = wdt_data->pld; | |
3736d4eb | 143 | u32 prescaler; |
e51c288e KS |
144 | u64 stage_timeout64; |
145 | u32 stage_timeout; | |
146 | u32 remainder; | |
147 | u8 stage_cfg; | |
148 | ||
3736d4eb AB |
149 | #if GCC_VERSION < 40400 |
150 | /* work around a bug compiling do_div() */ | |
151 | prescaler = READ_ONCE(kempld_prescaler[PRESCALER_21]); | |
152 | #else | |
153 | prescaler = kempld_prescaler[PRESCALER_21]; | |
154 | #endif | |
155 | ||
e51c288e KS |
156 | if (!stage) |
157 | return -EINVAL; | |
158 | ||
159 | stage_timeout64 = (u64)timeout * pld->pld_clock; | |
160 | remainder = do_div(stage_timeout64, prescaler); | |
161 | if (remainder) | |
162 | stage_timeout64++; | |
163 | ||
164 | if (stage_timeout64 > stage->mask) | |
165 | return -EINVAL; | |
166 | ||
167 | stage_timeout = stage_timeout64 & stage->mask; | |
168 | ||
169 | kempld_get_mutex(pld); | |
170 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); | |
171 | stage_cfg &= ~STAGE_CFG_PRESCALER_MASK; | |
a9e0436b | 172 | stage_cfg |= STAGE_CFG_SET_PRESCALER(PRESCALER_21); |
e51c288e KS |
173 | kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg); |
174 | kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id), | |
175 | stage_timeout); | |
176 | kempld_release_mutex(pld); | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | /* | |
182 | * kempld_get_mutex must be called prior to calling this function. | |
183 | */ | |
184 | static unsigned int kempld_wdt_get_timeout(struct kempld_wdt_data *wdt_data, | |
185 | struct kempld_wdt_stage *stage) | |
186 | { | |
187 | struct kempld_device_data *pld = wdt_data->pld; | |
188 | unsigned int timeout; | |
189 | u64 stage_timeout; | |
190 | u32 prescaler; | |
191 | u32 remainder; | |
192 | u8 stage_cfg; | |
193 | ||
194 | if (!stage->mask) | |
195 | return 0; | |
196 | ||
197 | stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id)); | |
198 | stage_timeout = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id)); | |
199 | prescaler = kempld_prescaler[STAGE_CFG_GET_PRESCALER(stage_cfg)]; | |
200 | ||
201 | stage_timeout = (stage_timeout & stage->mask) * prescaler; | |
202 | remainder = do_div(stage_timeout, pld->pld_clock); | |
203 | if (remainder) | |
204 | stage_timeout++; | |
205 | ||
206 | timeout = stage_timeout; | |
207 | WARN_ON_ONCE(timeout != stage_timeout); | |
208 | ||
209 | return timeout; | |
210 | } | |
211 | ||
212 | static int kempld_wdt_set_timeout(struct watchdog_device *wdd, | |
213 | unsigned int timeout) | |
214 | { | |
215 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
216 | struct kempld_wdt_stage *pretimeout_stage; | |
217 | struct kempld_wdt_stage *timeout_stage; | |
218 | int ret; | |
219 | ||
220 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; | |
221 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
222 | ||
223 | if (pretimeout_stage->mask && wdt_data->pretimeout > 0) | |
224 | timeout = wdt_data->pretimeout; | |
225 | ||
226 | ret = kempld_wdt_set_stage_action(wdt_data, timeout_stage, | |
227 | ACTION_RESET); | |
228 | if (ret) | |
229 | return ret; | |
230 | ret = kempld_wdt_set_stage_timeout(wdt_data, timeout_stage, | |
231 | timeout); | |
232 | if (ret) | |
233 | return ret; | |
234 | ||
235 | wdd->timeout = timeout; | |
236 | return 0; | |
237 | } | |
238 | ||
239 | static int kempld_wdt_set_pretimeout(struct watchdog_device *wdd, | |
240 | unsigned int pretimeout) | |
241 | { | |
242 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
243 | struct kempld_wdt_stage *pretimeout_stage; | |
244 | u8 action = ACTION_NONE; | |
245 | int ret; | |
246 | ||
247 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
248 | ||
249 | if (!pretimeout_stage->mask) | |
250 | return -ENXIO; | |
251 | ||
252 | if (pretimeout > wdd->timeout) | |
253 | return -EINVAL; | |
254 | ||
255 | if (pretimeout > 0) | |
256 | action = ACTION_NMI; | |
257 | ||
258 | ret = kempld_wdt_set_stage_action(wdt_data, pretimeout_stage, | |
259 | action); | |
260 | if (ret) | |
261 | return ret; | |
262 | ret = kempld_wdt_set_stage_timeout(wdt_data, pretimeout_stage, | |
263 | wdd->timeout - pretimeout); | |
264 | if (ret) | |
265 | return ret; | |
266 | ||
267 | wdt_data->pretimeout = pretimeout; | |
268 | return 0; | |
269 | } | |
270 | ||
271 | static void kempld_wdt_update_timeouts(struct kempld_wdt_data *wdt_data) | |
272 | { | |
273 | struct kempld_device_data *pld = wdt_data->pld; | |
274 | struct kempld_wdt_stage *pretimeout_stage; | |
275 | struct kempld_wdt_stage *timeout_stage; | |
276 | unsigned int pretimeout, timeout; | |
277 | ||
278 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
279 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; | |
280 | ||
281 | kempld_get_mutex(pld); | |
282 | pretimeout = kempld_wdt_get_timeout(wdt_data, pretimeout_stage); | |
283 | timeout = kempld_wdt_get_timeout(wdt_data, timeout_stage); | |
284 | kempld_release_mutex(pld); | |
285 | ||
286 | if (pretimeout) | |
287 | wdt_data->pretimeout = timeout; | |
288 | else | |
289 | wdt_data->pretimeout = 0; | |
290 | ||
291 | wdt_data->wdd.timeout = pretimeout + timeout; | |
292 | } | |
293 | ||
294 | static int kempld_wdt_start(struct watchdog_device *wdd) | |
295 | { | |
296 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
297 | struct kempld_device_data *pld = wdt_data->pld; | |
298 | u8 status; | |
299 | int ret; | |
300 | ||
301 | ret = kempld_wdt_set_timeout(wdd, wdd->timeout); | |
302 | if (ret) | |
303 | return ret; | |
304 | ||
305 | kempld_get_mutex(pld); | |
306 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
307 | status |= KEMPLD_WDT_CFG_ENABLE; | |
308 | kempld_write8(pld, KEMPLD_WDT_CFG, status); | |
309 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
310 | kempld_release_mutex(pld); | |
311 | ||
312 | /* Check if the watchdog was enabled */ | |
313 | if (!(status & KEMPLD_WDT_CFG_ENABLE)) | |
314 | return -EACCES; | |
315 | ||
316 | return 0; | |
317 | } | |
318 | ||
319 | static int kempld_wdt_stop(struct watchdog_device *wdd) | |
320 | { | |
321 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
322 | struct kempld_device_data *pld = wdt_data->pld; | |
323 | u8 status; | |
324 | ||
325 | kempld_get_mutex(pld); | |
326 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
327 | status &= ~KEMPLD_WDT_CFG_ENABLE; | |
328 | kempld_write8(pld, KEMPLD_WDT_CFG, status); | |
329 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
330 | kempld_release_mutex(pld); | |
331 | ||
332 | /* Check if the watchdog was disabled */ | |
333 | if (status & KEMPLD_WDT_CFG_ENABLE) | |
334 | return -EACCES; | |
335 | ||
336 | return 0; | |
337 | } | |
338 | ||
339 | static int kempld_wdt_keepalive(struct watchdog_device *wdd) | |
340 | { | |
341 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
342 | struct kempld_device_data *pld = wdt_data->pld; | |
343 | ||
344 | kempld_get_mutex(pld); | |
345 | kempld_write8(pld, KEMPLD_WDT_KICK, 'K'); | |
346 | kempld_release_mutex(pld); | |
347 | ||
348 | return 0; | |
349 | } | |
350 | ||
351 | static long kempld_wdt_ioctl(struct watchdog_device *wdd, unsigned int cmd, | |
352 | unsigned long arg) | |
353 | { | |
354 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
355 | void __user *argp = (void __user *)arg; | |
356 | int ret = -ENOIOCTLCMD; | |
357 | int __user *p = argp; | |
358 | int new_value; | |
359 | ||
360 | switch (cmd) { | |
361 | case WDIOC_SETPRETIMEOUT: | |
362 | if (get_user(new_value, p)) | |
363 | return -EFAULT; | |
364 | ret = kempld_wdt_set_pretimeout(wdd, new_value); | |
365 | if (ret) | |
366 | return ret; | |
367 | ret = kempld_wdt_keepalive(wdd); | |
368 | break; | |
369 | case WDIOC_GETPRETIMEOUT: | |
b3970bde | 370 | ret = put_user(wdt_data->pretimeout, (int __user *)arg); |
e51c288e KS |
371 | break; |
372 | } | |
373 | ||
374 | return ret; | |
375 | } | |
376 | ||
377 | static int kempld_wdt_probe_stages(struct watchdog_device *wdd) | |
378 | { | |
379 | struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd); | |
380 | struct kempld_device_data *pld = wdt_data->pld; | |
381 | struct kempld_wdt_stage *pretimeout_stage; | |
382 | struct kempld_wdt_stage *timeout_stage; | |
383 | u8 index, data, data_orig; | |
384 | u32 mask; | |
385 | int i, j; | |
386 | ||
387 | pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT]; | |
388 | timeout_stage = &wdt_data->stage[STAGE_TIMEOUT]; | |
389 | ||
390 | pretimeout_stage->mask = 0; | |
391 | timeout_stage->mask = 0; | |
392 | ||
393 | for (i = 0; i < 3; i++) { | |
394 | index = KEMPLD_WDT_STAGE_TIMEOUT(i); | |
395 | mask = 0; | |
396 | ||
397 | kempld_get_mutex(pld); | |
398 | /* Probe each byte individually. */ | |
399 | for (j = 0; j < 4; j++) { | |
400 | data_orig = kempld_read8(pld, index + j); | |
401 | kempld_write8(pld, index + j, 0x00); | |
402 | data = kempld_read8(pld, index + j); | |
403 | /* A failed write means this byte is reserved */ | |
404 | if (data != 0x00) | |
405 | break; | |
406 | kempld_write8(pld, index + j, data_orig); | |
407 | mask |= 0xff << (j * 8); | |
408 | } | |
409 | kempld_release_mutex(pld); | |
410 | ||
411 | /* Assign available stages to timeout and pretimeout */ | |
412 | if (!timeout_stage->mask) { | |
413 | timeout_stage->mask = mask; | |
414 | timeout_stage->id = i; | |
415 | } else { | |
416 | if (pld->feature_mask & KEMPLD_FEATURE_BIT_NMI) { | |
417 | pretimeout_stage->mask = timeout_stage->mask; | |
418 | timeout_stage->mask = mask; | |
419 | pretimeout_stage->id = timeout_stage->id; | |
420 | timeout_stage->id = i; | |
421 | } | |
422 | break; | |
423 | } | |
424 | } | |
425 | ||
426 | if (!timeout_stage->mask) | |
427 | return -ENODEV; | |
428 | ||
429 | return 0; | |
430 | } | |
431 | ||
6c368932 | 432 | static const struct watchdog_info kempld_wdt_info = { |
e51c288e KS |
433 | .identity = "KEMPLD Watchdog", |
434 | .options = WDIOF_SETTIMEOUT | | |
435 | WDIOF_KEEPALIVEPING | | |
436 | WDIOF_MAGICCLOSE | | |
437 | WDIOF_PRETIMEOUT | |
438 | }; | |
439 | ||
85f15cfc | 440 | static const struct watchdog_ops kempld_wdt_ops = { |
e51c288e KS |
441 | .owner = THIS_MODULE, |
442 | .start = kempld_wdt_start, | |
443 | .stop = kempld_wdt_stop, | |
444 | .ping = kempld_wdt_keepalive, | |
445 | .set_timeout = kempld_wdt_set_timeout, | |
446 | .ioctl = kempld_wdt_ioctl, | |
447 | }; | |
448 | ||
449 | static int kempld_wdt_probe(struct platform_device *pdev) | |
450 | { | |
451 | struct kempld_device_data *pld = dev_get_drvdata(pdev->dev.parent); | |
452 | struct kempld_wdt_data *wdt_data; | |
453 | struct device *dev = &pdev->dev; | |
454 | struct watchdog_device *wdd; | |
455 | u8 status; | |
456 | int ret = 0; | |
457 | ||
458 | wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL); | |
459 | if (!wdt_data) | |
460 | return -ENOMEM; | |
461 | ||
462 | wdt_data->pld = pld; | |
463 | wdd = &wdt_data->wdd; | |
464 | wdd->parent = dev; | |
465 | ||
466 | kempld_get_mutex(pld); | |
467 | status = kempld_read8(pld, KEMPLD_WDT_CFG); | |
468 | kempld_release_mutex(pld); | |
469 | ||
470 | /* Enable nowayout if watchdog is already locked */ | |
471 | if (status & (KEMPLD_WDT_CFG_ENABLE_LOCK | | |
472 | KEMPLD_WDT_CFG_GLOBAL_LOCK)) { | |
473 | if (!nowayout) | |
474 | dev_warn(dev, | |
475 | "Forcing nowayout - watchdog lock enabled!\n"); | |
476 | nowayout = true; | |
477 | } | |
478 | ||
479 | wdd->info = &kempld_wdt_info; | |
480 | wdd->ops = &kempld_wdt_ops; | |
481 | ||
482 | watchdog_set_drvdata(wdd, wdt_data); | |
483 | watchdog_set_nowayout(wdd, nowayout); | |
484 | ||
485 | ret = kempld_wdt_probe_stages(wdd); | |
486 | if (ret) | |
487 | return ret; | |
488 | ||
489 | kempld_wdt_set_timeout(wdd, timeout); | |
490 | kempld_wdt_set_pretimeout(wdd, pretimeout); | |
491 | ||
492 | /* Check if watchdog is already enabled */ | |
493 | if (status & KEMPLD_WDT_CFG_ENABLE) { | |
494 | /* Get current watchdog settings */ | |
495 | kempld_wdt_update_timeouts(wdt_data); | |
496 | dev_info(dev, "Watchdog was already enabled\n"); | |
497 | } | |
498 | ||
499 | platform_set_drvdata(pdev, wdt_data); | |
500 | ret = watchdog_register_device(wdd); | |
501 | if (ret) | |
502 | return ret; | |
503 | ||
504 | dev_info(dev, "Watchdog registered with %ds timeout\n", wdd->timeout); | |
505 | ||
506 | return 0; | |
507 | } | |
508 | ||
509 | static void kempld_wdt_shutdown(struct platform_device *pdev) | |
510 | { | |
511 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
512 | ||
513 | kempld_wdt_stop(&wdt_data->wdd); | |
514 | } | |
515 | ||
516 | static int kempld_wdt_remove(struct platform_device *pdev) | |
517 | { | |
518 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
519 | struct watchdog_device *wdd = &wdt_data->wdd; | |
520 | int ret = 0; | |
521 | ||
522 | if (!nowayout) | |
523 | ret = kempld_wdt_stop(wdd); | |
524 | watchdog_unregister_device(wdd); | |
525 | ||
526 | return ret; | |
527 | } | |
528 | ||
529 | #ifdef CONFIG_PM | |
530 | /* Disable watchdog if it is active during suspend */ | |
531 | static int kempld_wdt_suspend(struct platform_device *pdev, | |
532 | pm_message_t message) | |
533 | { | |
534 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
535 | struct kempld_device_data *pld = wdt_data->pld; | |
536 | struct watchdog_device *wdd = &wdt_data->wdd; | |
537 | ||
538 | kempld_get_mutex(pld); | |
539 | wdt_data->pm_status_store = kempld_read8(pld, KEMPLD_WDT_CFG); | |
540 | kempld_release_mutex(pld); | |
541 | ||
542 | kempld_wdt_update_timeouts(wdt_data); | |
543 | ||
544 | if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE) | |
545 | return kempld_wdt_stop(wdd); | |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
550 | /* Enable watchdog and configure it if necessary */ | |
551 | static int kempld_wdt_resume(struct platform_device *pdev) | |
552 | { | |
553 | struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev); | |
554 | struct watchdog_device *wdd = &wdt_data->wdd; | |
555 | ||
556 | /* | |
557 | * If watchdog was stopped before suspend be sure it gets disabled | |
558 | * again, for the case BIOS has enabled it during resume | |
559 | */ | |
560 | if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE) | |
561 | return kempld_wdt_start(wdd); | |
562 | else | |
563 | return kempld_wdt_stop(wdd); | |
564 | } | |
565 | #else | |
566 | #define kempld_wdt_suspend NULL | |
567 | #define kempld_wdt_resume NULL | |
568 | #endif | |
569 | ||
570 | static struct platform_driver kempld_wdt_driver = { | |
571 | .driver = { | |
572 | .name = "kempld-wdt", | |
e51c288e KS |
573 | }, |
574 | .probe = kempld_wdt_probe, | |
575 | .remove = kempld_wdt_remove, | |
576 | .shutdown = kempld_wdt_shutdown, | |
577 | .suspend = kempld_wdt_suspend, | |
578 | .resume = kempld_wdt_resume, | |
579 | }; | |
580 | ||
581 | module_platform_driver(kempld_wdt_driver); | |
582 | ||
583 | MODULE_DESCRIPTION("KEM PLD Watchdog Driver"); | |
584 | MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>"); | |
585 | MODULE_LICENSE("GPL"); |