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1 | /* | |
2 | * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework | |
3 | * for Non-CPU Devices. | |
4 | * | |
5 | * Copyright (C) 2011 Samsung Electronics | |
6 | * MyungJoo Ham <myungjoo.ham@samsung.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/stat.h> | |
21 | #include <linux/pm_opp.h> | |
22 | #include <linux/devfreq.h> | |
23 | #include <linux/workqueue.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/list.h> | |
26 | #include <linux/printk.h> | |
27 | #include <linux/hrtimer.h> | |
28 | #include "governor.h" | |
29 | ||
30 | static struct class *devfreq_class; | |
31 | ||
32 | /* | |
33 | * devfreq core provides delayed work based load monitoring helper | |
34 | * functions. Governors can use these or can implement their own | |
35 | * monitoring mechanism. | |
36 | */ | |
37 | static struct workqueue_struct *devfreq_wq; | |
38 | ||
39 | /* The list of all device-devfreq governors */ | |
40 | static LIST_HEAD(devfreq_governor_list); | |
41 | /* The list of all device-devfreq */ | |
42 | static LIST_HEAD(devfreq_list); | |
43 | static DEFINE_MUTEX(devfreq_list_lock); | |
44 | ||
45 | /** | |
46 | * find_device_devfreq() - find devfreq struct using device pointer | |
47 | * @dev: device pointer used to lookup device devfreq. | |
48 | * | |
49 | * Search the list of device devfreqs and return the matched device's | |
50 | * devfreq info. devfreq_list_lock should be held by the caller. | |
51 | */ | |
52 | static struct devfreq *find_device_devfreq(struct device *dev) | |
53 | { | |
54 | struct devfreq *tmp_devfreq; | |
55 | ||
56 | if (IS_ERR_OR_NULL(dev)) { | |
57 | pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); | |
58 | return ERR_PTR(-EINVAL); | |
59 | } | |
60 | WARN(!mutex_is_locked(&devfreq_list_lock), | |
61 | "devfreq_list_lock must be locked."); | |
62 | ||
63 | list_for_each_entry(tmp_devfreq, &devfreq_list, node) { | |
64 | if (tmp_devfreq->dev.parent == dev) | |
65 | return tmp_devfreq; | |
66 | } | |
67 | ||
68 | return ERR_PTR(-ENODEV); | |
69 | } | |
70 | ||
71 | /** | |
72 | * devfreq_get_freq_level() - Lookup freq_table for the frequency | |
73 | * @devfreq: the devfreq instance | |
74 | * @freq: the target frequency | |
75 | */ | |
76 | static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq) | |
77 | { | |
78 | int lev; | |
79 | ||
80 | for (lev = 0; lev < devfreq->profile->max_state; lev++) | |
81 | if (freq == devfreq->profile->freq_table[lev]) | |
82 | return lev; | |
83 | ||
84 | return -EINVAL; | |
85 | } | |
86 | ||
87 | /** | |
88 | * devfreq_update_status() - Update statistics of devfreq behavior | |
89 | * @devfreq: the devfreq instance | |
90 | * @freq: the update target frequency | |
91 | */ | |
92 | static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) | |
93 | { | |
94 | int lev, prev_lev, ret = 0; | |
95 | unsigned long cur_time; | |
96 | ||
97 | cur_time = jiffies; | |
98 | ||
99 | prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq); | |
100 | if (prev_lev < 0) { | |
101 | ret = prev_lev; | |
102 | goto out; | |
103 | } | |
104 | ||
105 | devfreq->time_in_state[prev_lev] += | |
106 | cur_time - devfreq->last_stat_updated; | |
107 | ||
108 | lev = devfreq_get_freq_level(devfreq, freq); | |
109 | if (lev < 0) { | |
110 | ret = lev; | |
111 | goto out; | |
112 | } | |
113 | ||
114 | if (lev != prev_lev) { | |
115 | devfreq->trans_table[(prev_lev * | |
116 | devfreq->profile->max_state) + lev]++; | |
117 | devfreq->total_trans++; | |
118 | } | |
119 | ||
120 | out: | |
121 | devfreq->last_stat_updated = cur_time; | |
122 | return ret; | |
123 | } | |
124 | ||
125 | /** | |
126 | * find_devfreq_governor() - find devfreq governor from name | |
127 | * @name: name of the governor | |
128 | * | |
129 | * Search the list of devfreq governors and return the matched | |
130 | * governor's pointer. devfreq_list_lock should be held by the caller. | |
131 | */ | |
132 | static struct devfreq_governor *find_devfreq_governor(const char *name) | |
133 | { | |
134 | struct devfreq_governor *tmp_governor; | |
135 | ||
136 | if (IS_ERR_OR_NULL(name)) { | |
137 | pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); | |
138 | return ERR_PTR(-EINVAL); | |
139 | } | |
140 | WARN(!mutex_is_locked(&devfreq_list_lock), | |
141 | "devfreq_list_lock must be locked."); | |
142 | ||
143 | list_for_each_entry(tmp_governor, &devfreq_governor_list, node) { | |
144 | if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN)) | |
145 | return tmp_governor; | |
146 | } | |
147 | ||
148 | return ERR_PTR(-ENODEV); | |
149 | } | |
150 | ||
151 | /* Load monitoring helper functions for governors use */ | |
152 | ||
153 | /** | |
154 | * update_devfreq() - Reevaluate the device and configure frequency. | |
155 | * @devfreq: the devfreq instance. | |
156 | * | |
157 | * Note: Lock devfreq->lock before calling update_devfreq | |
158 | * This function is exported for governors. | |
159 | */ | |
160 | int update_devfreq(struct devfreq *devfreq) | |
161 | { | |
162 | unsigned long freq; | |
163 | int err = 0; | |
164 | u32 flags = 0; | |
165 | ||
166 | if (!mutex_is_locked(&devfreq->lock)) { | |
167 | WARN(true, "devfreq->lock must be locked by the caller.\n"); | |
168 | return -EINVAL; | |
169 | } | |
170 | ||
171 | if (!devfreq->governor) | |
172 | return -EINVAL; | |
173 | ||
174 | /* Reevaluate the proper frequency */ | |
175 | err = devfreq->governor->get_target_freq(devfreq, &freq); | |
176 | if (err) | |
177 | return err; | |
178 | ||
179 | /* | |
180 | * Adjust the frequency with user freq and QoS. | |
181 | * | |
182 | * List from the highest priority | |
183 | * max_freq | |
184 | * min_freq | |
185 | */ | |
186 | ||
187 | if (devfreq->min_freq && freq < devfreq->min_freq) { | |
188 | freq = devfreq->min_freq; | |
189 | flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ | |
190 | } | |
191 | if (devfreq->max_freq && freq > devfreq->max_freq) { | |
192 | freq = devfreq->max_freq; | |
193 | flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ | |
194 | } | |
195 | ||
196 | err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); | |
197 | if (err) | |
198 | return err; | |
199 | ||
200 | if (devfreq->profile->freq_table) | |
201 | if (devfreq_update_status(devfreq, freq)) | |
202 | dev_err(&devfreq->dev, | |
203 | "Couldn't update frequency transition information.\n"); | |
204 | ||
205 | devfreq->previous_freq = freq; | |
206 | return err; | |
207 | } | |
208 | EXPORT_SYMBOL(update_devfreq); | |
209 | ||
210 | /** | |
211 | * devfreq_monitor() - Periodically poll devfreq objects. | |
212 | * @work: the work struct used to run devfreq_monitor periodically. | |
213 | * | |
214 | */ | |
215 | static void devfreq_monitor(struct work_struct *work) | |
216 | { | |
217 | int err; | |
218 | struct devfreq *devfreq = container_of(work, | |
219 | struct devfreq, work.work); | |
220 | ||
221 | mutex_lock(&devfreq->lock); | |
222 | err = update_devfreq(devfreq); | |
223 | if (err) | |
224 | dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err); | |
225 | ||
226 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
227 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
228 | mutex_unlock(&devfreq->lock); | |
229 | } | |
230 | ||
231 | /** | |
232 | * devfreq_monitor_start() - Start load monitoring of devfreq instance | |
233 | * @devfreq: the devfreq instance. | |
234 | * | |
235 | * Helper function for starting devfreq device load monitoing. By | |
236 | * default delayed work based monitoring is supported. Function | |
237 | * to be called from governor in response to DEVFREQ_GOV_START | |
238 | * event when device is added to devfreq framework. | |
239 | */ | |
240 | void devfreq_monitor_start(struct devfreq *devfreq) | |
241 | { | |
242 | INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); | |
243 | if (devfreq->profile->polling_ms) | |
244 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
245 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
246 | } | |
247 | EXPORT_SYMBOL(devfreq_monitor_start); | |
248 | ||
249 | /** | |
250 | * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance | |
251 | * @devfreq: the devfreq instance. | |
252 | * | |
253 | * Helper function to stop devfreq device load monitoing. Function | |
254 | * to be called from governor in response to DEVFREQ_GOV_STOP | |
255 | * event when device is removed from devfreq framework. | |
256 | */ | |
257 | void devfreq_monitor_stop(struct devfreq *devfreq) | |
258 | { | |
259 | cancel_delayed_work_sync(&devfreq->work); | |
260 | } | |
261 | EXPORT_SYMBOL(devfreq_monitor_stop); | |
262 | ||
263 | /** | |
264 | * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance | |
265 | * @devfreq: the devfreq instance. | |
266 | * | |
267 | * Helper function to suspend devfreq device load monitoing. Function | |
268 | * to be called from governor in response to DEVFREQ_GOV_SUSPEND | |
269 | * event or when polling interval is set to zero. | |
270 | * | |
271 | * Note: Though this function is same as devfreq_monitor_stop(), | |
272 | * intentionally kept separate to provide hooks for collecting | |
273 | * transition statistics. | |
274 | */ | |
275 | void devfreq_monitor_suspend(struct devfreq *devfreq) | |
276 | { | |
277 | mutex_lock(&devfreq->lock); | |
278 | if (devfreq->stop_polling) { | |
279 | mutex_unlock(&devfreq->lock); | |
280 | return; | |
281 | } | |
282 | ||
283 | devfreq_update_status(devfreq, devfreq->previous_freq); | |
284 | devfreq->stop_polling = true; | |
285 | mutex_unlock(&devfreq->lock); | |
286 | cancel_delayed_work_sync(&devfreq->work); | |
287 | } | |
288 | EXPORT_SYMBOL(devfreq_monitor_suspend); | |
289 | ||
290 | /** | |
291 | * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance | |
292 | * @devfreq: the devfreq instance. | |
293 | * | |
294 | * Helper function to resume devfreq device load monitoing. Function | |
295 | * to be called from governor in response to DEVFREQ_GOV_RESUME | |
296 | * event or when polling interval is set to non-zero. | |
297 | */ | |
298 | void devfreq_monitor_resume(struct devfreq *devfreq) | |
299 | { | |
300 | unsigned long freq; | |
301 | ||
302 | mutex_lock(&devfreq->lock); | |
303 | if (!devfreq->stop_polling) | |
304 | goto out; | |
305 | ||
306 | if (!delayed_work_pending(&devfreq->work) && | |
307 | devfreq->profile->polling_ms) | |
308 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
309 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
310 | ||
311 | devfreq->last_stat_updated = jiffies; | |
312 | devfreq->stop_polling = false; | |
313 | ||
314 | if (devfreq->profile->get_cur_freq && | |
315 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
316 | devfreq->previous_freq = freq; | |
317 | ||
318 | out: | |
319 | mutex_unlock(&devfreq->lock); | |
320 | } | |
321 | EXPORT_SYMBOL(devfreq_monitor_resume); | |
322 | ||
323 | /** | |
324 | * devfreq_interval_update() - Update device devfreq monitoring interval | |
325 | * @devfreq: the devfreq instance. | |
326 | * @delay: new polling interval to be set. | |
327 | * | |
328 | * Helper function to set new load monitoring polling interval. Function | |
329 | * to be called from governor in response to DEVFREQ_GOV_INTERVAL event. | |
330 | */ | |
331 | void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay) | |
332 | { | |
333 | unsigned int cur_delay = devfreq->profile->polling_ms; | |
334 | unsigned int new_delay = *delay; | |
335 | ||
336 | mutex_lock(&devfreq->lock); | |
337 | devfreq->profile->polling_ms = new_delay; | |
338 | ||
339 | if (devfreq->stop_polling) | |
340 | goto out; | |
341 | ||
342 | /* if new delay is zero, stop polling */ | |
343 | if (!new_delay) { | |
344 | mutex_unlock(&devfreq->lock); | |
345 | cancel_delayed_work_sync(&devfreq->work); | |
346 | return; | |
347 | } | |
348 | ||
349 | /* if current delay is zero, start polling with new delay */ | |
350 | if (!cur_delay) { | |
351 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
352 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
353 | goto out; | |
354 | } | |
355 | ||
356 | /* if current delay is greater than new delay, restart polling */ | |
357 | if (cur_delay > new_delay) { | |
358 | mutex_unlock(&devfreq->lock); | |
359 | cancel_delayed_work_sync(&devfreq->work); | |
360 | mutex_lock(&devfreq->lock); | |
361 | if (!devfreq->stop_polling) | |
362 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
363 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
364 | } | |
365 | out: | |
366 | mutex_unlock(&devfreq->lock); | |
367 | } | |
368 | EXPORT_SYMBOL(devfreq_interval_update); | |
369 | ||
370 | /** | |
371 | * devfreq_notifier_call() - Notify that the device frequency requirements | |
372 | * has been changed out of devfreq framework. | |
373 | * @nb: the notifier_block (supposed to be devfreq->nb) | |
374 | * @type: not used | |
375 | * @devp: not used | |
376 | * | |
377 | * Called by a notifier that uses devfreq->nb. | |
378 | */ | |
379 | static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, | |
380 | void *devp) | |
381 | { | |
382 | struct devfreq *devfreq = container_of(nb, struct devfreq, nb); | |
383 | int ret; | |
384 | ||
385 | mutex_lock(&devfreq->lock); | |
386 | ret = update_devfreq(devfreq); | |
387 | mutex_unlock(&devfreq->lock); | |
388 | ||
389 | return ret; | |
390 | } | |
391 | ||
392 | /** | |
393 | * _remove_devfreq() - Remove devfreq from the list and release its resources. | |
394 | * @devfreq: the devfreq struct | |
395 | */ | |
396 | static void _remove_devfreq(struct devfreq *devfreq) | |
397 | { | |
398 | mutex_lock(&devfreq_list_lock); | |
399 | if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { | |
400 | mutex_unlock(&devfreq_list_lock); | |
401 | dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); | |
402 | return; | |
403 | } | |
404 | list_del(&devfreq->node); | |
405 | mutex_unlock(&devfreq_list_lock); | |
406 | ||
407 | if (devfreq->governor) | |
408 | devfreq->governor->event_handler(devfreq, | |
409 | DEVFREQ_GOV_STOP, NULL); | |
410 | ||
411 | if (devfreq->profile->exit) | |
412 | devfreq->profile->exit(devfreq->dev.parent); | |
413 | ||
414 | mutex_destroy(&devfreq->lock); | |
415 | kfree(devfreq); | |
416 | } | |
417 | ||
418 | /** | |
419 | * devfreq_dev_release() - Callback for struct device to release the device. | |
420 | * @dev: the devfreq device | |
421 | * | |
422 | * This calls _remove_devfreq() if _remove_devfreq() is not called. | |
423 | */ | |
424 | static void devfreq_dev_release(struct device *dev) | |
425 | { | |
426 | struct devfreq *devfreq = to_devfreq(dev); | |
427 | ||
428 | _remove_devfreq(devfreq); | |
429 | } | |
430 | ||
431 | /** | |
432 | * devfreq_add_device() - Add devfreq feature to the device | |
433 | * @dev: the device to add devfreq feature. | |
434 | * @profile: device-specific profile to run devfreq. | |
435 | * @governor_name: name of the policy to choose frequency. | |
436 | * @data: private data for the governor. The devfreq framework does not | |
437 | * touch this value. | |
438 | */ | |
439 | struct devfreq *devfreq_add_device(struct device *dev, | |
440 | struct devfreq_dev_profile *profile, | |
441 | const char *governor_name, | |
442 | void *data) | |
443 | { | |
444 | struct devfreq *devfreq; | |
445 | struct devfreq_governor *governor; | |
446 | int err = 0; | |
447 | ||
448 | if (!dev || !profile || !governor_name) { | |
449 | dev_err(dev, "%s: Invalid parameters.\n", __func__); | |
450 | return ERR_PTR(-EINVAL); | |
451 | } | |
452 | ||
453 | mutex_lock(&devfreq_list_lock); | |
454 | devfreq = find_device_devfreq(dev); | |
455 | mutex_unlock(&devfreq_list_lock); | |
456 | if (!IS_ERR(devfreq)) { | |
457 | dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__); | |
458 | err = -EINVAL; | |
459 | goto err_out; | |
460 | } | |
461 | ||
462 | devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); | |
463 | if (!devfreq) { | |
464 | dev_err(dev, "%s: Unable to create devfreq for the device\n", | |
465 | __func__); | |
466 | err = -ENOMEM; | |
467 | goto err_out; | |
468 | } | |
469 | ||
470 | mutex_init(&devfreq->lock); | |
471 | mutex_lock(&devfreq->lock); | |
472 | devfreq->dev.parent = dev; | |
473 | devfreq->dev.class = devfreq_class; | |
474 | devfreq->dev.release = devfreq_dev_release; | |
475 | devfreq->profile = profile; | |
476 | strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); | |
477 | devfreq->previous_freq = profile->initial_freq; | |
478 | devfreq->data = data; | |
479 | devfreq->nb.notifier_call = devfreq_notifier_call; | |
480 | ||
481 | devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * | |
482 | devfreq->profile->max_state * | |
483 | devfreq->profile->max_state, | |
484 | GFP_KERNEL); | |
485 | devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned long) * | |
486 | devfreq->profile->max_state, | |
487 | GFP_KERNEL); | |
488 | devfreq->last_stat_updated = jiffies; | |
489 | ||
490 | dev_set_name(&devfreq->dev, "%s", dev_name(dev)); | |
491 | err = device_register(&devfreq->dev); | |
492 | if (err) { | |
493 | put_device(&devfreq->dev); | |
494 | mutex_unlock(&devfreq->lock); | |
495 | goto err_dev; | |
496 | } | |
497 | ||
498 | mutex_unlock(&devfreq->lock); | |
499 | ||
500 | mutex_lock(&devfreq_list_lock); | |
501 | list_add(&devfreq->node, &devfreq_list); | |
502 | ||
503 | governor = find_devfreq_governor(devfreq->governor_name); | |
504 | if (!IS_ERR(governor)) | |
505 | devfreq->governor = governor; | |
506 | if (devfreq->governor) | |
507 | err = devfreq->governor->event_handler(devfreq, | |
508 | DEVFREQ_GOV_START, NULL); | |
509 | mutex_unlock(&devfreq_list_lock); | |
510 | if (err) { | |
511 | dev_err(dev, "%s: Unable to start governor for the device\n", | |
512 | __func__); | |
513 | goto err_init; | |
514 | } | |
515 | ||
516 | return devfreq; | |
517 | ||
518 | err_init: | |
519 | list_del(&devfreq->node); | |
520 | device_unregister(&devfreq->dev); | |
521 | err_dev: | |
522 | kfree(devfreq); | |
523 | err_out: | |
524 | return ERR_PTR(err); | |
525 | } | |
526 | EXPORT_SYMBOL(devfreq_add_device); | |
527 | ||
528 | /** | |
529 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
530 | * @devfreq: the devfreq instance to be removed | |
531 | * | |
532 | * The opposite of devfreq_add_device(). | |
533 | */ | |
534 | int devfreq_remove_device(struct devfreq *devfreq) | |
535 | { | |
536 | if (!devfreq) | |
537 | return -EINVAL; | |
538 | ||
539 | device_unregister(&devfreq->dev); | |
540 | put_device(&devfreq->dev); | |
541 | ||
542 | return 0; | |
543 | } | |
544 | EXPORT_SYMBOL(devfreq_remove_device); | |
545 | ||
546 | static int devm_devfreq_dev_match(struct device *dev, void *res, void *data) | |
547 | { | |
548 | struct devfreq **r = res; | |
549 | ||
550 | if (WARN_ON(!r || !*r)) | |
551 | return 0; | |
552 | ||
553 | return *r == data; | |
554 | } | |
555 | ||
556 | static void devm_devfreq_dev_release(struct device *dev, void *res) | |
557 | { | |
558 | devfreq_remove_device(*(struct devfreq **)res); | |
559 | } | |
560 | ||
561 | /** | |
562 | * devm_devfreq_add_device() - Resource-managed devfreq_add_device() | |
563 | * @dev: the device to add devfreq feature. | |
564 | * @profile: device-specific profile to run devfreq. | |
565 | * @governor_name: name of the policy to choose frequency. | |
566 | * @data: private data for the governor. The devfreq framework does not | |
567 | * touch this value. | |
568 | * | |
569 | * This function manages automatically the memory of devfreq device using device | |
570 | * resource management and simplify the free operation for memory of devfreq | |
571 | * device. | |
572 | */ | |
573 | struct devfreq *devm_devfreq_add_device(struct device *dev, | |
574 | struct devfreq_dev_profile *profile, | |
575 | const char *governor_name, | |
576 | void *data) | |
577 | { | |
578 | struct devfreq **ptr, *devfreq; | |
579 | ||
580 | ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL); | |
581 | if (!ptr) | |
582 | return ERR_PTR(-ENOMEM); | |
583 | ||
584 | devfreq = devfreq_add_device(dev, profile, governor_name, data); | |
585 | if (IS_ERR(devfreq)) { | |
586 | devres_free(ptr); | |
587 | return ERR_PTR(-ENOMEM); | |
588 | } | |
589 | ||
590 | *ptr = devfreq; | |
591 | devres_add(dev, ptr); | |
592 | ||
593 | return devfreq; | |
594 | } | |
595 | EXPORT_SYMBOL(devm_devfreq_add_device); | |
596 | ||
597 | /** | |
598 | * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device() | |
599 | * @dev: the device to add devfreq feature. | |
600 | * @devfreq: the devfreq instance to be removed | |
601 | */ | |
602 | void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq) | |
603 | { | |
604 | WARN_ON(devres_release(dev, devm_devfreq_dev_release, | |
605 | devm_devfreq_dev_match, devfreq)); | |
606 | } | |
607 | EXPORT_SYMBOL(devm_devfreq_remove_device); | |
608 | ||
609 | /** | |
610 | * devfreq_suspend_device() - Suspend devfreq of a device. | |
611 | * @devfreq: the devfreq instance to be suspended | |
612 | * | |
613 | * This function is intended to be called by the pm callbacks | |
614 | * (e.g., runtime_suspend, suspend) of the device driver that | |
615 | * holds the devfreq. | |
616 | */ | |
617 | int devfreq_suspend_device(struct devfreq *devfreq) | |
618 | { | |
619 | if (!devfreq) | |
620 | return -EINVAL; | |
621 | ||
622 | if (!devfreq->governor) | |
623 | return 0; | |
624 | ||
625 | return devfreq->governor->event_handler(devfreq, | |
626 | DEVFREQ_GOV_SUSPEND, NULL); | |
627 | } | |
628 | EXPORT_SYMBOL(devfreq_suspend_device); | |
629 | ||
630 | /** | |
631 | * devfreq_resume_device() - Resume devfreq of a device. | |
632 | * @devfreq: the devfreq instance to be resumed | |
633 | * | |
634 | * This function is intended to be called by the pm callbacks | |
635 | * (e.g., runtime_resume, resume) of the device driver that | |
636 | * holds the devfreq. | |
637 | */ | |
638 | int devfreq_resume_device(struct devfreq *devfreq) | |
639 | { | |
640 | if (!devfreq) | |
641 | return -EINVAL; | |
642 | ||
643 | if (!devfreq->governor) | |
644 | return 0; | |
645 | ||
646 | return devfreq->governor->event_handler(devfreq, | |
647 | DEVFREQ_GOV_RESUME, NULL); | |
648 | } | |
649 | EXPORT_SYMBOL(devfreq_resume_device); | |
650 | ||
651 | /** | |
652 | * devfreq_add_governor() - Add devfreq governor | |
653 | * @governor: the devfreq governor to be added | |
654 | */ | |
655 | int devfreq_add_governor(struct devfreq_governor *governor) | |
656 | { | |
657 | struct devfreq_governor *g; | |
658 | struct devfreq *devfreq; | |
659 | int err = 0; | |
660 | ||
661 | if (!governor) { | |
662 | pr_err("%s: Invalid parameters.\n", __func__); | |
663 | return -EINVAL; | |
664 | } | |
665 | ||
666 | mutex_lock(&devfreq_list_lock); | |
667 | g = find_devfreq_governor(governor->name); | |
668 | if (!IS_ERR(g)) { | |
669 | pr_err("%s: governor %s already registered\n", __func__, | |
670 | g->name); | |
671 | err = -EINVAL; | |
672 | goto err_out; | |
673 | } | |
674 | ||
675 | list_add(&governor->node, &devfreq_governor_list); | |
676 | ||
677 | list_for_each_entry(devfreq, &devfreq_list, node) { | |
678 | int ret = 0; | |
679 | struct device *dev = devfreq->dev.parent; | |
680 | ||
681 | if (!strncmp(devfreq->governor_name, governor->name, | |
682 | DEVFREQ_NAME_LEN)) { | |
683 | /* The following should never occur */ | |
684 | if (devfreq->governor) { | |
685 | dev_warn(dev, | |
686 | "%s: Governor %s already present\n", | |
687 | __func__, devfreq->governor->name); | |
688 | ret = devfreq->governor->event_handler(devfreq, | |
689 | DEVFREQ_GOV_STOP, NULL); | |
690 | if (ret) { | |
691 | dev_warn(dev, | |
692 | "%s: Governor %s stop = %d\n", | |
693 | __func__, | |
694 | devfreq->governor->name, ret); | |
695 | } | |
696 | /* Fall through */ | |
697 | } | |
698 | devfreq->governor = governor; | |
699 | ret = devfreq->governor->event_handler(devfreq, | |
700 | DEVFREQ_GOV_START, NULL); | |
701 | if (ret) { | |
702 | dev_warn(dev, "%s: Governor %s start=%d\n", | |
703 | __func__, devfreq->governor->name, | |
704 | ret); | |
705 | } | |
706 | } | |
707 | } | |
708 | ||
709 | err_out: | |
710 | mutex_unlock(&devfreq_list_lock); | |
711 | ||
712 | return err; | |
713 | } | |
714 | EXPORT_SYMBOL(devfreq_add_governor); | |
715 | ||
716 | /** | |
717 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
718 | * @governor: the devfreq governor to be removed | |
719 | */ | |
720 | int devfreq_remove_governor(struct devfreq_governor *governor) | |
721 | { | |
722 | struct devfreq_governor *g; | |
723 | struct devfreq *devfreq; | |
724 | int err = 0; | |
725 | ||
726 | if (!governor) { | |
727 | pr_err("%s: Invalid parameters.\n", __func__); | |
728 | return -EINVAL; | |
729 | } | |
730 | ||
731 | mutex_lock(&devfreq_list_lock); | |
732 | g = find_devfreq_governor(governor->name); | |
733 | if (IS_ERR(g)) { | |
734 | pr_err("%s: governor %s not registered\n", __func__, | |
735 | governor->name); | |
736 | err = PTR_ERR(g); | |
737 | goto err_out; | |
738 | } | |
739 | list_for_each_entry(devfreq, &devfreq_list, node) { | |
740 | int ret; | |
741 | struct device *dev = devfreq->dev.parent; | |
742 | ||
743 | if (!strncmp(devfreq->governor_name, governor->name, | |
744 | DEVFREQ_NAME_LEN)) { | |
745 | /* we should have a devfreq governor! */ | |
746 | if (!devfreq->governor) { | |
747 | dev_warn(dev, "%s: Governor %s NOT present\n", | |
748 | __func__, governor->name); | |
749 | continue; | |
750 | /* Fall through */ | |
751 | } | |
752 | ret = devfreq->governor->event_handler(devfreq, | |
753 | DEVFREQ_GOV_STOP, NULL); | |
754 | if (ret) { | |
755 | dev_warn(dev, "%s: Governor %s stop=%d\n", | |
756 | __func__, devfreq->governor->name, | |
757 | ret); | |
758 | } | |
759 | devfreq->governor = NULL; | |
760 | } | |
761 | } | |
762 | ||
763 | list_del(&governor->node); | |
764 | err_out: | |
765 | mutex_unlock(&devfreq_list_lock); | |
766 | ||
767 | return err; | |
768 | } | |
769 | EXPORT_SYMBOL(devfreq_remove_governor); | |
770 | ||
771 | static ssize_t governor_show(struct device *dev, | |
772 | struct device_attribute *attr, char *buf) | |
773 | { | |
774 | if (!to_devfreq(dev)->governor) | |
775 | return -EINVAL; | |
776 | ||
777 | return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); | |
778 | } | |
779 | ||
780 | static ssize_t governor_store(struct device *dev, struct device_attribute *attr, | |
781 | const char *buf, size_t count) | |
782 | { | |
783 | struct devfreq *df = to_devfreq(dev); | |
784 | int ret; | |
785 | char str_governor[DEVFREQ_NAME_LEN + 1]; | |
786 | struct devfreq_governor *governor; | |
787 | ||
788 | ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); | |
789 | if (ret != 1) | |
790 | return -EINVAL; | |
791 | ||
792 | mutex_lock(&devfreq_list_lock); | |
793 | governor = find_devfreq_governor(str_governor); | |
794 | if (IS_ERR(governor)) { | |
795 | ret = PTR_ERR(governor); | |
796 | goto out; | |
797 | } | |
798 | if (df->governor == governor) | |
799 | goto out; | |
800 | ||
801 | if (df->governor) { | |
802 | ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); | |
803 | if (ret) { | |
804 | dev_warn(dev, "%s: Governor %s not stopped(%d)\n", | |
805 | __func__, df->governor->name, ret); | |
806 | goto out; | |
807 | } | |
808 | } | |
809 | df->governor = governor; | |
810 | strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); | |
811 | ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); | |
812 | if (ret) | |
813 | dev_warn(dev, "%s: Governor %s not started(%d)\n", | |
814 | __func__, df->governor->name, ret); | |
815 | out: | |
816 | mutex_unlock(&devfreq_list_lock); | |
817 | ||
818 | if (!ret) | |
819 | ret = count; | |
820 | return ret; | |
821 | } | |
822 | static DEVICE_ATTR_RW(governor); | |
823 | ||
824 | static ssize_t available_governors_show(struct device *d, | |
825 | struct device_attribute *attr, | |
826 | char *buf) | |
827 | { | |
828 | struct devfreq_governor *tmp_governor; | |
829 | ssize_t count = 0; | |
830 | ||
831 | mutex_lock(&devfreq_list_lock); | |
832 | list_for_each_entry(tmp_governor, &devfreq_governor_list, node) | |
833 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
834 | "%s ", tmp_governor->name); | |
835 | mutex_unlock(&devfreq_list_lock); | |
836 | ||
837 | /* Truncate the trailing space */ | |
838 | if (count) | |
839 | count--; | |
840 | ||
841 | count += sprintf(&buf[count], "\n"); | |
842 | ||
843 | return count; | |
844 | } | |
845 | static DEVICE_ATTR_RO(available_governors); | |
846 | ||
847 | static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, | |
848 | char *buf) | |
849 | { | |
850 | unsigned long freq; | |
851 | struct devfreq *devfreq = to_devfreq(dev); | |
852 | ||
853 | if (devfreq->profile->get_cur_freq && | |
854 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
855 | return sprintf(buf, "%lu\n", freq); | |
856 | ||
857 | return sprintf(buf, "%lu\n", devfreq->previous_freq); | |
858 | } | |
859 | static DEVICE_ATTR_RO(cur_freq); | |
860 | ||
861 | static ssize_t target_freq_show(struct device *dev, | |
862 | struct device_attribute *attr, char *buf) | |
863 | { | |
864 | return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); | |
865 | } | |
866 | static DEVICE_ATTR_RO(target_freq); | |
867 | ||
868 | static ssize_t polling_interval_show(struct device *dev, | |
869 | struct device_attribute *attr, char *buf) | |
870 | { | |
871 | return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); | |
872 | } | |
873 | ||
874 | static ssize_t polling_interval_store(struct device *dev, | |
875 | struct device_attribute *attr, | |
876 | const char *buf, size_t count) | |
877 | { | |
878 | struct devfreq *df = to_devfreq(dev); | |
879 | unsigned int value; | |
880 | int ret; | |
881 | ||
882 | if (!df->governor) | |
883 | return -EINVAL; | |
884 | ||
885 | ret = sscanf(buf, "%u", &value); | |
886 | if (ret != 1) | |
887 | return -EINVAL; | |
888 | ||
889 | df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); | |
890 | ret = count; | |
891 | ||
892 | return ret; | |
893 | } | |
894 | static DEVICE_ATTR_RW(polling_interval); | |
895 | ||
896 | static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, | |
897 | const char *buf, size_t count) | |
898 | { | |
899 | struct devfreq *df = to_devfreq(dev); | |
900 | unsigned long value; | |
901 | int ret; | |
902 | unsigned long max; | |
903 | ||
904 | ret = sscanf(buf, "%lu", &value); | |
905 | if (ret != 1) | |
906 | return -EINVAL; | |
907 | ||
908 | mutex_lock(&df->lock); | |
909 | max = df->max_freq; | |
910 | if (value && max && value > max) { | |
911 | ret = -EINVAL; | |
912 | goto unlock; | |
913 | } | |
914 | ||
915 | df->min_freq = value; | |
916 | update_devfreq(df); | |
917 | ret = count; | |
918 | unlock: | |
919 | mutex_unlock(&df->lock); | |
920 | return ret; | |
921 | } | |
922 | ||
923 | static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, | |
924 | char *buf) | |
925 | { | |
926 | return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); | |
927 | } | |
928 | ||
929 | static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, | |
930 | const char *buf, size_t count) | |
931 | { | |
932 | struct devfreq *df = to_devfreq(dev); | |
933 | unsigned long value; | |
934 | int ret; | |
935 | unsigned long min; | |
936 | ||
937 | ret = sscanf(buf, "%lu", &value); | |
938 | if (ret != 1) | |
939 | return -EINVAL; | |
940 | ||
941 | mutex_lock(&df->lock); | |
942 | min = df->min_freq; | |
943 | if (value && min && value < min) { | |
944 | ret = -EINVAL; | |
945 | goto unlock; | |
946 | } | |
947 | ||
948 | df->max_freq = value; | |
949 | update_devfreq(df); | |
950 | ret = count; | |
951 | unlock: | |
952 | mutex_unlock(&df->lock); | |
953 | return ret; | |
954 | } | |
955 | static DEVICE_ATTR_RW(min_freq); | |
956 | ||
957 | static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, | |
958 | char *buf) | |
959 | { | |
960 | return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); | |
961 | } | |
962 | static DEVICE_ATTR_RW(max_freq); | |
963 | ||
964 | static ssize_t available_frequencies_show(struct device *d, | |
965 | struct device_attribute *attr, | |
966 | char *buf) | |
967 | { | |
968 | struct devfreq *df = to_devfreq(d); | |
969 | struct device *dev = df->dev.parent; | |
970 | struct dev_pm_opp *opp; | |
971 | ssize_t count = 0; | |
972 | unsigned long freq = 0; | |
973 | ||
974 | rcu_read_lock(); | |
975 | do { | |
976 | opp = dev_pm_opp_find_freq_ceil(dev, &freq); | |
977 | if (IS_ERR(opp)) | |
978 | break; | |
979 | ||
980 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
981 | "%lu ", freq); | |
982 | freq++; | |
983 | } while (1); | |
984 | rcu_read_unlock(); | |
985 | ||
986 | /* Truncate the trailing space */ | |
987 | if (count) | |
988 | count--; | |
989 | ||
990 | count += sprintf(&buf[count], "\n"); | |
991 | ||
992 | return count; | |
993 | } | |
994 | static DEVICE_ATTR_RO(available_frequencies); | |
995 | ||
996 | static ssize_t trans_stat_show(struct device *dev, | |
997 | struct device_attribute *attr, char *buf) | |
998 | { | |
999 | struct devfreq *devfreq = to_devfreq(dev); | |
1000 | ssize_t len; | |
1001 | int i, j; | |
1002 | unsigned int max_state = devfreq->profile->max_state; | |
1003 | ||
1004 | if (!devfreq->stop_polling && | |
1005 | devfreq_update_status(devfreq, devfreq->previous_freq)) | |
1006 | return 0; | |
1007 | ||
1008 | len = sprintf(buf, " From : To\n"); | |
1009 | len += sprintf(buf + len, " :"); | |
1010 | for (i = 0; i < max_state; i++) | |
1011 | len += sprintf(buf + len, "%8u", | |
1012 | devfreq->profile->freq_table[i]); | |
1013 | ||
1014 | len += sprintf(buf + len, " time(ms)\n"); | |
1015 | ||
1016 | for (i = 0; i < max_state; i++) { | |
1017 | if (devfreq->profile->freq_table[i] | |
1018 | == devfreq->previous_freq) { | |
1019 | len += sprintf(buf + len, "*"); | |
1020 | } else { | |
1021 | len += sprintf(buf + len, " "); | |
1022 | } | |
1023 | len += sprintf(buf + len, "%8u:", | |
1024 | devfreq->profile->freq_table[i]); | |
1025 | for (j = 0; j < max_state; j++) | |
1026 | len += sprintf(buf + len, "%8u", | |
1027 | devfreq->trans_table[(i * max_state) + j]); | |
1028 | len += sprintf(buf + len, "%10u\n", | |
1029 | jiffies_to_msecs(devfreq->time_in_state[i])); | |
1030 | } | |
1031 | ||
1032 | len += sprintf(buf + len, "Total transition : %u\n", | |
1033 | devfreq->total_trans); | |
1034 | return len; | |
1035 | } | |
1036 | static DEVICE_ATTR_RO(trans_stat); | |
1037 | ||
1038 | static struct attribute *devfreq_attrs[] = { | |
1039 | &dev_attr_governor.attr, | |
1040 | &dev_attr_available_governors.attr, | |
1041 | &dev_attr_cur_freq.attr, | |
1042 | &dev_attr_available_frequencies.attr, | |
1043 | &dev_attr_target_freq.attr, | |
1044 | &dev_attr_polling_interval.attr, | |
1045 | &dev_attr_min_freq.attr, | |
1046 | &dev_attr_max_freq.attr, | |
1047 | &dev_attr_trans_stat.attr, | |
1048 | NULL, | |
1049 | }; | |
1050 | ATTRIBUTE_GROUPS(devfreq); | |
1051 | ||
1052 | static int __init devfreq_init(void) | |
1053 | { | |
1054 | devfreq_class = class_create(THIS_MODULE, "devfreq"); | |
1055 | if (IS_ERR(devfreq_class)) { | |
1056 | pr_err("%s: couldn't create class\n", __FILE__); | |
1057 | return PTR_ERR(devfreq_class); | |
1058 | } | |
1059 | ||
1060 | devfreq_wq = create_freezable_workqueue("devfreq_wq"); | |
1061 | if (!devfreq_wq) { | |
1062 | class_destroy(devfreq_class); | |
1063 | pr_err("%s: couldn't create workqueue\n", __FILE__); | |
1064 | return -ENOMEM; | |
1065 | } | |
1066 | devfreq_class->dev_groups = devfreq_groups; | |
1067 | ||
1068 | return 0; | |
1069 | } | |
1070 | subsys_initcall(devfreq_init); | |
1071 | ||
1072 | static void __exit devfreq_exit(void) | |
1073 | { | |
1074 | class_destroy(devfreq_class); | |
1075 | destroy_workqueue(devfreq_wq); | |
1076 | } | |
1077 | module_exit(devfreq_exit); | |
1078 | ||
1079 | /* | |
1080 | * The followings are helper functions for devfreq user device drivers with | |
1081 | * OPP framework. | |
1082 | */ | |
1083 | ||
1084 | /** | |
1085 | * devfreq_recommended_opp() - Helper function to get proper OPP for the | |
1086 | * freq value given to target callback. | |
1087 | * @dev: The devfreq user device. (parent of devfreq) | |
1088 | * @freq: The frequency given to target function | |
1089 | * @flags: Flags handed from devfreq framework. | |
1090 | * | |
1091 | * Locking: This function must be called under rcu_read_lock(). opp is a rcu | |
1092 | * protected pointer. The reason for the same is that the opp pointer which is | |
1093 | * returned will remain valid for use with opp_get_{voltage, freq} only while | |
1094 | * under the locked area. The pointer returned must be used prior to unlocking | |
1095 | * with rcu_read_unlock() to maintain the integrity of the pointer. | |
1096 | */ | |
1097 | struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, | |
1098 | unsigned long *freq, | |
1099 | u32 flags) | |
1100 | { | |
1101 | struct dev_pm_opp *opp; | |
1102 | ||
1103 | if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { | |
1104 | /* The freq is an upper bound. opp should be lower */ | |
1105 | opp = dev_pm_opp_find_freq_floor(dev, freq); | |
1106 | ||
1107 | /* If not available, use the closest opp */ | |
1108 | if (opp == ERR_PTR(-ERANGE)) | |
1109 | opp = dev_pm_opp_find_freq_ceil(dev, freq); | |
1110 | } else { | |
1111 | /* The freq is an lower bound. opp should be higher */ | |
1112 | opp = dev_pm_opp_find_freq_ceil(dev, freq); | |
1113 | ||
1114 | /* If not available, use the closest opp */ | |
1115 | if (opp == ERR_PTR(-ERANGE)) | |
1116 | opp = dev_pm_opp_find_freq_floor(dev, freq); | |
1117 | } | |
1118 | ||
1119 | return opp; | |
1120 | } | |
1121 | EXPORT_SYMBOL(devfreq_recommended_opp); | |
1122 | ||
1123 | /** | |
1124 | * devfreq_register_opp_notifier() - Helper function to get devfreq notified | |
1125 | * for any changes in the OPP availability | |
1126 | * changes | |
1127 | * @dev: The devfreq user device. (parent of devfreq) | |
1128 | * @devfreq: The devfreq object. | |
1129 | */ | |
1130 | int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1131 | { | |
1132 | struct srcu_notifier_head *nh; | |
1133 | int ret = 0; | |
1134 | ||
1135 | rcu_read_lock(); | |
1136 | nh = dev_pm_opp_get_notifier(dev); | |
1137 | if (IS_ERR(nh)) | |
1138 | ret = PTR_ERR(nh); | |
1139 | rcu_read_unlock(); | |
1140 | if (!ret) | |
1141 | ret = srcu_notifier_chain_register(nh, &devfreq->nb); | |
1142 | ||
1143 | return ret; | |
1144 | } | |
1145 | EXPORT_SYMBOL(devfreq_register_opp_notifier); | |
1146 | ||
1147 | /** | |
1148 | * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq | |
1149 | * notified for any changes in the OPP | |
1150 | * availability changes anymore. | |
1151 | * @dev: The devfreq user device. (parent of devfreq) | |
1152 | * @devfreq: The devfreq object. | |
1153 | * | |
1154 | * At exit() callback of devfreq_dev_profile, this must be included if | |
1155 | * devfreq_recommended_opp is used. | |
1156 | */ | |
1157 | int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1158 | { | |
1159 | struct srcu_notifier_head *nh; | |
1160 | int ret = 0; | |
1161 | ||
1162 | rcu_read_lock(); | |
1163 | nh = dev_pm_opp_get_notifier(dev); | |
1164 | if (IS_ERR(nh)) | |
1165 | ret = PTR_ERR(nh); | |
1166 | rcu_read_unlock(); | |
1167 | if (!ret) | |
1168 | ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); | |
1169 | ||
1170 | return ret; | |
1171 | } | |
1172 | EXPORT_SYMBOL(devfreq_unregister_opp_notifier); | |
1173 | ||
1174 | static void devm_devfreq_opp_release(struct device *dev, void *res) | |
1175 | { | |
1176 | devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res); | |
1177 | } | |
1178 | ||
1179 | /** | |
1180 | * devm_ devfreq_register_opp_notifier() | |
1181 | * - Resource-managed devfreq_register_opp_notifier() | |
1182 | * @dev: The devfreq user device. (parent of devfreq) | |
1183 | * @devfreq: The devfreq object. | |
1184 | */ | |
1185 | int devm_devfreq_register_opp_notifier(struct device *dev, | |
1186 | struct devfreq *devfreq) | |
1187 | { | |
1188 | struct devfreq **ptr; | |
1189 | int ret; | |
1190 | ||
1191 | ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL); | |
1192 | if (!ptr) | |
1193 | return -ENOMEM; | |
1194 | ||
1195 | ret = devfreq_register_opp_notifier(dev, devfreq); | |
1196 | if (ret) { | |
1197 | devres_free(ptr); | |
1198 | return ret; | |
1199 | } | |
1200 | ||
1201 | *ptr = devfreq; | |
1202 | devres_add(dev, ptr); | |
1203 | ||
1204 | return 0; | |
1205 | } | |
1206 | EXPORT_SYMBOL(devm_devfreq_register_opp_notifier); | |
1207 | ||
1208 | /** | |
1209 | * devm_devfreq_unregister_opp_notifier() | |
1210 | * - Resource-managed devfreq_unregister_opp_notifier() | |
1211 | * @dev: The devfreq user device. (parent of devfreq) | |
1212 | * @devfreq: The devfreq object. | |
1213 | */ | |
1214 | void devm_devfreq_unregister_opp_notifier(struct device *dev, | |
1215 | struct devfreq *devfreq) | |
1216 | { | |
1217 | WARN_ON(devres_release(dev, devm_devfreq_opp_release, | |
1218 | devm_devfreq_dev_match, devfreq)); | |
1219 | } | |
1220 | EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier); | |
1221 | ||
1222 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
1223 | MODULE_DESCRIPTION("devfreq class support"); | |
1224 | MODULE_LICENSE("GPL"); |