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Commit | Line | Data |
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a3c98b8b MH |
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> | |
952f6d13 | 18 | #include <linux/module.h> |
a3c98b8b | 19 | #include <linux/slab.h> |
952f6d13 | 20 | #include <linux/stat.h> |
e4db1c74 | 21 | #include <linux/pm_opp.h> |
a3c98b8b MH |
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 | ||
1a1357ea | 30 | static struct class *devfreq_class; |
a3c98b8b MH |
31 | |
32 | /* | |
7e6fdd4b RV |
33 | * devfreq core provides delayed work based load monitoring helper |
34 | * functions. Governors can use these or can implement their own | |
35 | * monitoring mechanism. | |
a3c98b8b | 36 | */ |
a3c98b8b | 37 | static struct workqueue_struct *devfreq_wq; |
a3c98b8b | 38 | |
3aa173b8 NM |
39 | /* The list of all device-devfreq governors */ |
40 | static LIST_HEAD(devfreq_governor_list); | |
a3c98b8b MH |
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 (unlikely(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 | ||
e552bbaf JL |
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 | { | |
e35d35a1 | 94 | int lev, prev_lev, ret = 0; |
e552bbaf JL |
95 | unsigned long cur_time; |
96 | ||
e552bbaf | 97 | cur_time = jiffies; |
e35d35a1 SK |
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] += | |
e552bbaf | 106 | cur_time - devfreq->last_stat_updated; |
e35d35a1 SK |
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) { | |
e552bbaf JL |
115 | devfreq->trans_table[(prev_lev * |
116 | devfreq->profile->max_state) + lev]++; | |
117 | devfreq->total_trans++; | |
118 | } | |
e552bbaf | 119 | |
e35d35a1 SK |
120 | out: |
121 | devfreq->last_stat_updated = cur_time; | |
122 | return ret; | |
e552bbaf JL |
123 | } |
124 | ||
3aa173b8 NM |
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 (unlikely(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 | ||
7e6fdd4b RV |
151 | /* Load monitoring helper functions for governors use */ |
152 | ||
a3c98b8b MH |
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; | |
ab5f299f | 164 | u32 flags = 0; |
a3c98b8b MH |
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 | ||
1b5c1be2 NM |
171 | if (!devfreq->governor) |
172 | return -EINVAL; | |
173 | ||
a3c98b8b MH |
174 | /* Reevaluate the proper frequency */ |
175 | err = devfreq->governor->get_target_freq(devfreq, &freq); | |
176 | if (err) | |
177 | return err; | |
178 | ||
ab5f299f MH |
179 | /* |
180 | * Adjust the freuqency with user freq and QoS. | |
181 | * | |
182 | * List from the highest proiority | |
183 | * max_freq (probably called by thermal when it's too hot) | |
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); | |
a3c98b8b MH |
197 | if (err) |
198 | return err; | |
199 | ||
e552bbaf JL |
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 | ||
a3c98b8b MH |
205 | devfreq->previous_freq = freq; |
206 | return err; | |
207 | } | |
2df5021f | 208 | EXPORT_SYMBOL(update_devfreq); |
a3c98b8b | 209 | |
7e6fdd4b RV |
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 | } | |
6dcdd8e3 | 247 | EXPORT_SYMBOL(devfreq_monitor_start); |
7e6fdd4b RV |
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 | } | |
6dcdd8e3 | 261 | EXPORT_SYMBOL(devfreq_monitor_stop); |
7e6fdd4b RV |
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 | ||
39688ce6 | 283 | devfreq_update_status(devfreq, devfreq->previous_freq); |
7e6fdd4b RV |
284 | devfreq->stop_polling = true; |
285 | mutex_unlock(&devfreq->lock); | |
286 | cancel_delayed_work_sync(&devfreq->work); | |
287 | } | |
6dcdd8e3 | 288 | EXPORT_SYMBOL(devfreq_monitor_suspend); |
7e6fdd4b RV |
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 | { | |
39688ce6 RV |
300 | unsigned long freq; |
301 | ||
7e6fdd4b RV |
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)); | |
39688ce6 RV |
310 | |
311 | devfreq->last_stat_updated = jiffies; | |
7e6fdd4b RV |
312 | devfreq->stop_polling = false; |
313 | ||
39688ce6 RV |
314 | if (devfreq->profile->get_cur_freq && |
315 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
316 | devfreq->previous_freq = freq; | |
317 | ||
7e6fdd4b RV |
318 | out: |
319 | mutex_unlock(&devfreq->lock); | |
320 | } | |
6dcdd8e3 | 321 | EXPORT_SYMBOL(devfreq_monitor_resume); |
7e6fdd4b RV |
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 | } | |
6dcdd8e3 | 368 | EXPORT_SYMBOL(devfreq_interval_update); |
a3c98b8b MH |
369 | |
370 | /** | |
371 | * devfreq_notifier_call() - Notify that the device frequency requirements | |
372 | * has been changed out of devfreq framework. | |
c5b4a1c1 NM |
373 | * @nb: the notifier_block (supposed to be devfreq->nb) |
374 | * @type: not used | |
375 | * @devp: not used | |
a3c98b8b MH |
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 | /** | |
7e6fdd4b | 393 | * _remove_devfreq() - Remove devfreq from the list and release its resources. |
a3c98b8b MH |
394 | * @devfreq: the devfreq struct |
395 | * @skip: skip calling device_unregister(). | |
a3c98b8b | 396 | */ |
585fc83e | 397 | static void _remove_devfreq(struct devfreq *devfreq) |
a3c98b8b | 398 | { |
7e6fdd4b RV |
399 | mutex_lock(&devfreq_list_lock); |
400 | if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { | |
401 | mutex_unlock(&devfreq_list_lock); | |
402 | dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); | |
a3c98b8b MH |
403 | return; |
404 | } | |
7e6fdd4b RV |
405 | list_del(&devfreq->node); |
406 | mutex_unlock(&devfreq_list_lock); | |
a3c98b8b | 407 | |
1b5c1be2 NM |
408 | if (devfreq->governor) |
409 | devfreq->governor->event_handler(devfreq, | |
410 | DEVFREQ_GOV_STOP, NULL); | |
a3c98b8b MH |
411 | |
412 | if (devfreq->profile->exit) | |
413 | devfreq->profile->exit(devfreq->dev.parent); | |
414 | ||
a3c98b8b | 415 | mutex_destroy(&devfreq->lock); |
a3c98b8b MH |
416 | kfree(devfreq); |
417 | } | |
418 | ||
419 | /** | |
420 | * devfreq_dev_release() - Callback for struct device to release the device. | |
421 | * @dev: the devfreq device | |
422 | * | |
423 | * This calls _remove_devfreq() if _remove_devfreq() is not called. | |
a3c98b8b MH |
424 | */ |
425 | static void devfreq_dev_release(struct device *dev) | |
426 | { | |
427 | struct devfreq *devfreq = to_devfreq(dev); | |
a3c98b8b | 428 | |
585fc83e | 429 | _remove_devfreq(devfreq); |
a3c98b8b MH |
430 | } |
431 | ||
432 | /** | |
433 | * devfreq_add_device() - Add devfreq feature to the device | |
434 | * @dev: the device to add devfreq feature. | |
435 | * @profile: device-specific profile to run devfreq. | |
1b5c1be2 | 436 | * @governor_name: name of the policy to choose frequency. |
a3c98b8b MH |
437 | * @data: private data for the governor. The devfreq framework does not |
438 | * touch this value. | |
439 | */ | |
440 | struct devfreq *devfreq_add_device(struct device *dev, | |
441 | struct devfreq_dev_profile *profile, | |
1b5c1be2 | 442 | const char *governor_name, |
a3c98b8b MH |
443 | void *data) |
444 | { | |
445 | struct devfreq *devfreq; | |
1b5c1be2 | 446 | struct devfreq_governor *governor; |
a3c98b8b MH |
447 | int err = 0; |
448 | ||
1b5c1be2 | 449 | if (!dev || !profile || !governor_name) { |
a3c98b8b MH |
450 | dev_err(dev, "%s: Invalid parameters.\n", __func__); |
451 | return ERR_PTR(-EINVAL); | |
452 | } | |
453 | ||
7e6fdd4b RV |
454 | mutex_lock(&devfreq_list_lock); |
455 | devfreq = find_device_devfreq(dev); | |
456 | mutex_unlock(&devfreq_list_lock); | |
457 | if (!IS_ERR(devfreq)) { | |
458 | dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__); | |
459 | err = -EINVAL; | |
460 | goto err_out; | |
a3c98b8b MH |
461 | } |
462 | ||
463 | devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); | |
464 | if (!devfreq) { | |
465 | dev_err(dev, "%s: Unable to create devfreq for the device\n", | |
466 | __func__); | |
467 | err = -ENOMEM; | |
3f19f08a | 468 | goto err_out; |
a3c98b8b MH |
469 | } |
470 | ||
471 | mutex_init(&devfreq->lock); | |
472 | mutex_lock(&devfreq->lock); | |
473 | devfreq->dev.parent = dev; | |
474 | devfreq->dev.class = devfreq_class; | |
475 | devfreq->dev.release = devfreq_dev_release; | |
476 | devfreq->profile = profile; | |
1b5c1be2 | 477 | strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); |
a3c98b8b MH |
478 | devfreq->previous_freq = profile->initial_freq; |
479 | devfreq->data = data; | |
a3c98b8b MH |
480 | devfreq->nb.notifier_call = devfreq_notifier_call; |
481 | ||
e552bbaf JL |
482 | devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * |
483 | devfreq->profile->max_state * | |
484 | devfreq->profile->max_state, | |
485 | GFP_KERNEL); | |
486 | devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) * | |
487 | devfreq->profile->max_state, | |
488 | GFP_KERNEL); | |
489 | devfreq->last_stat_updated = jiffies; | |
490 | ||
02aa2a37 | 491 | dev_set_name(&devfreq->dev, "%s", dev_name(dev)); |
a3c98b8b MH |
492 | err = device_register(&devfreq->dev); |
493 | if (err) { | |
494 | put_device(&devfreq->dev); | |
7e6fdd4b | 495 | mutex_unlock(&devfreq->lock); |
a3c98b8b MH |
496 | goto err_dev; |
497 | } | |
498 | ||
a3c98b8b MH |
499 | mutex_unlock(&devfreq->lock); |
500 | ||
a3c98b8b | 501 | mutex_lock(&devfreq_list_lock); |
a3c98b8b MH |
502 | list_add(&devfreq->node, &devfreq_list); |
503 | ||
1b5c1be2 NM |
504 | governor = find_devfreq_governor(devfreq->governor_name); |
505 | if (!IS_ERR(governor)) | |
506 | devfreq->governor = governor; | |
507 | if (devfreq->governor) | |
508 | err = devfreq->governor->event_handler(devfreq, | |
509 | DEVFREQ_GOV_START, NULL); | |
a3c98b8b | 510 | mutex_unlock(&devfreq_list_lock); |
7e6fdd4b RV |
511 | if (err) { |
512 | dev_err(dev, "%s: Unable to start governor for the device\n", | |
513 | __func__); | |
514 | goto err_init; | |
a3c98b8b | 515 | } |
7e6fdd4b | 516 | |
3f19f08a AL |
517 | return devfreq; |
518 | ||
a3c98b8b | 519 | err_init: |
7e6fdd4b | 520 | list_del(&devfreq->node); |
a3c98b8b MH |
521 | device_unregister(&devfreq->dev); |
522 | err_dev: | |
a3c98b8b | 523 | kfree(devfreq); |
3f19f08a AL |
524 | err_out: |
525 | return ERR_PTR(err); | |
a3c98b8b | 526 | } |
7e6fdd4b | 527 | EXPORT_SYMBOL(devfreq_add_device); |
a3c98b8b MH |
528 | |
529 | /** | |
530 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
c5b4a1c1 | 531 | * @devfreq: the devfreq instance to be removed |
de9c7394 MH |
532 | * |
533 | * The opposite of devfreq_add_device(). | |
a3c98b8b MH |
534 | */ |
535 | int devfreq_remove_device(struct devfreq *devfreq) | |
536 | { | |
537 | if (!devfreq) | |
538 | return -EINVAL; | |
539 | ||
585fc83e CC |
540 | device_unregister(&devfreq->dev); |
541 | put_device(&devfreq->dev); | |
9f3bdd4f | 542 | |
a3c98b8b MH |
543 | return 0; |
544 | } | |
7e6fdd4b | 545 | EXPORT_SYMBOL(devfreq_remove_device); |
a3c98b8b | 546 | |
206c30cf RV |
547 | /** |
548 | * devfreq_suspend_device() - Suspend devfreq of a device. | |
549 | * @devfreq: the devfreq instance to be suspended | |
de9c7394 MH |
550 | * |
551 | * This function is intended to be called by the pm callbacks | |
552 | * (e.g., runtime_suspend, suspend) of the device driver that | |
553 | * holds the devfreq. | |
206c30cf RV |
554 | */ |
555 | int devfreq_suspend_device(struct devfreq *devfreq) | |
556 | { | |
a3c98b8b MH |
557 | if (!devfreq) |
558 | return -EINVAL; | |
559 | ||
1b5c1be2 NM |
560 | if (!devfreq->governor) |
561 | return 0; | |
562 | ||
206c30cf RV |
563 | return devfreq->governor->event_handler(devfreq, |
564 | DEVFREQ_GOV_SUSPEND, NULL); | |
565 | } | |
566 | EXPORT_SYMBOL(devfreq_suspend_device); | |
567 | ||
568 | /** | |
569 | * devfreq_resume_device() - Resume devfreq of a device. | |
570 | * @devfreq: the devfreq instance to be resumed | |
de9c7394 MH |
571 | * |
572 | * This function is intended to be called by the pm callbacks | |
573 | * (e.g., runtime_resume, resume) of the device driver that | |
574 | * holds the devfreq. | |
206c30cf RV |
575 | */ |
576 | int devfreq_resume_device(struct devfreq *devfreq) | |
577 | { | |
578 | if (!devfreq) | |
579 | return -EINVAL; | |
580 | ||
1b5c1be2 NM |
581 | if (!devfreq->governor) |
582 | return 0; | |
583 | ||
206c30cf RV |
584 | return devfreq->governor->event_handler(devfreq, |
585 | DEVFREQ_GOV_RESUME, NULL); | |
586 | } | |
587 | EXPORT_SYMBOL(devfreq_resume_device); | |
588 | ||
3aa173b8 NM |
589 | /** |
590 | * devfreq_add_governor() - Add devfreq governor | |
591 | * @governor: the devfreq governor to be added | |
592 | */ | |
593 | int devfreq_add_governor(struct devfreq_governor *governor) | |
594 | { | |
595 | struct devfreq_governor *g; | |
1b5c1be2 | 596 | struct devfreq *devfreq; |
3aa173b8 NM |
597 | int err = 0; |
598 | ||
599 | if (!governor) { | |
600 | pr_err("%s: Invalid parameters.\n", __func__); | |
601 | return -EINVAL; | |
602 | } | |
603 | ||
604 | mutex_lock(&devfreq_list_lock); | |
605 | g = find_devfreq_governor(governor->name); | |
606 | if (!IS_ERR(g)) { | |
607 | pr_err("%s: governor %s already registered\n", __func__, | |
608 | g->name); | |
609 | err = -EINVAL; | |
610 | goto err_out; | |
611 | } | |
9f3bdd4f | 612 | |
3aa173b8 NM |
613 | list_add(&governor->node, &devfreq_governor_list); |
614 | ||
1b5c1be2 NM |
615 | list_for_each_entry(devfreq, &devfreq_list, node) { |
616 | int ret = 0; | |
617 | struct device *dev = devfreq->dev.parent; | |
618 | ||
619 | if (!strncmp(devfreq->governor_name, governor->name, | |
620 | DEVFREQ_NAME_LEN)) { | |
621 | /* The following should never occur */ | |
622 | if (devfreq->governor) { | |
623 | dev_warn(dev, | |
624 | "%s: Governor %s already present\n", | |
625 | __func__, devfreq->governor->name); | |
626 | ret = devfreq->governor->event_handler(devfreq, | |
627 | DEVFREQ_GOV_STOP, NULL); | |
628 | if (ret) { | |
629 | dev_warn(dev, | |
630 | "%s: Governor %s stop = %d\n", | |
631 | __func__, | |
632 | devfreq->governor->name, ret); | |
633 | } | |
634 | /* Fall through */ | |
635 | } | |
636 | devfreq->governor = governor; | |
637 | ret = devfreq->governor->event_handler(devfreq, | |
638 | DEVFREQ_GOV_START, NULL); | |
639 | if (ret) { | |
640 | dev_warn(dev, "%s: Governor %s start=%d\n", | |
641 | __func__, devfreq->governor->name, | |
642 | ret); | |
643 | } | |
a3c98b8b MH |
644 | } |
645 | } | |
646 | ||
3aa173b8 NM |
647 | err_out: |
648 | mutex_unlock(&devfreq_list_lock); | |
a3c98b8b | 649 | |
3aa173b8 NM |
650 | return err; |
651 | } | |
652 | EXPORT_SYMBOL(devfreq_add_governor); | |
a3c98b8b | 653 | |
3aa173b8 NM |
654 | /** |
655 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
656 | * @governor: the devfreq governor to be removed | |
657 | */ | |
658 | int devfreq_remove_governor(struct devfreq_governor *governor) | |
659 | { | |
660 | struct devfreq_governor *g; | |
1b5c1be2 | 661 | struct devfreq *devfreq; |
3aa173b8 NM |
662 | int err = 0; |
663 | ||
664 | if (!governor) { | |
665 | pr_err("%s: Invalid parameters.\n", __func__); | |
666 | return -EINVAL; | |
667 | } | |
668 | ||
669 | mutex_lock(&devfreq_list_lock); | |
670 | g = find_devfreq_governor(governor->name); | |
671 | if (IS_ERR(g)) { | |
672 | pr_err("%s: governor %s not registered\n", __func__, | |
b9e1c8e8 | 673 | governor->name); |
f9c08e2a | 674 | err = PTR_ERR(g); |
3aa173b8 NM |
675 | goto err_out; |
676 | } | |
1b5c1be2 NM |
677 | list_for_each_entry(devfreq, &devfreq_list, node) { |
678 | int ret; | |
679 | struct device *dev = devfreq->dev.parent; | |
680 | ||
681 | if (!strncmp(devfreq->governor_name, governor->name, | |
682 | DEVFREQ_NAME_LEN)) { | |
683 | /* we should have a devfreq governor! */ | |
684 | if (!devfreq->governor) { | |
685 | dev_warn(dev, "%s: Governor %s NOT present\n", | |
686 | __func__, governor->name); | |
687 | continue; | |
688 | /* Fall through */ | |
689 | } | |
690 | ret = devfreq->governor->event_handler(devfreq, | |
691 | DEVFREQ_GOV_STOP, NULL); | |
692 | if (ret) { | |
693 | dev_warn(dev, "%s: Governor %s stop=%d\n", | |
694 | __func__, devfreq->governor->name, | |
695 | ret); | |
696 | } | |
697 | devfreq->governor = NULL; | |
698 | } | |
699 | } | |
3aa173b8 NM |
700 | |
701 | list_del(&governor->node); | |
702 | err_out: | |
703 | mutex_unlock(&devfreq_list_lock); | |
704 | ||
705 | return err; | |
a3c98b8b | 706 | } |
3aa173b8 | 707 | EXPORT_SYMBOL(devfreq_remove_governor); |
a3c98b8b | 708 | |
a93d6b0a | 709 | static ssize_t governor_show(struct device *dev, |
9005b650 MH |
710 | struct device_attribute *attr, char *buf) |
711 | { | |
1b5c1be2 NM |
712 | if (!to_devfreq(dev)->governor) |
713 | return -EINVAL; | |
714 | ||
9005b650 MH |
715 | return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); |
716 | } | |
717 | ||
a93d6b0a | 718 | static ssize_t governor_store(struct device *dev, struct device_attribute *attr, |
0359d1af NM |
719 | const char *buf, size_t count) |
720 | { | |
721 | struct devfreq *df = to_devfreq(dev); | |
722 | int ret; | |
723 | char str_governor[DEVFREQ_NAME_LEN + 1]; | |
724 | struct devfreq_governor *governor; | |
725 | ||
726 | ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); | |
727 | if (ret != 1) | |
728 | return -EINVAL; | |
729 | ||
730 | mutex_lock(&devfreq_list_lock); | |
731 | governor = find_devfreq_governor(str_governor); | |
732 | if (IS_ERR(governor)) { | |
733 | ret = PTR_ERR(governor); | |
734 | goto out; | |
735 | } | |
736 | if (df->governor == governor) | |
737 | goto out; | |
738 | ||
739 | if (df->governor) { | |
740 | ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); | |
741 | if (ret) { | |
742 | dev_warn(dev, "%s: Governor %s not stopped(%d)\n", | |
743 | __func__, df->governor->name, ret); | |
744 | goto out; | |
745 | } | |
746 | } | |
747 | df->governor = governor; | |
748 | strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); | |
749 | ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); | |
750 | if (ret) | |
751 | dev_warn(dev, "%s: Governor %s not started(%d)\n", | |
752 | __func__, df->governor->name, ret); | |
753 | out: | |
754 | mutex_unlock(&devfreq_list_lock); | |
755 | ||
756 | if (!ret) | |
757 | ret = count; | |
758 | return ret; | |
759 | } | |
a93d6b0a GKH |
760 | static DEVICE_ATTR_RW(governor); |
761 | ||
762 | static ssize_t available_governors_show(struct device *d, | |
763 | struct device_attribute *attr, | |
764 | char *buf) | |
50a5b33e NM |
765 | { |
766 | struct devfreq_governor *tmp_governor; | |
767 | ssize_t count = 0; | |
768 | ||
769 | mutex_lock(&devfreq_list_lock); | |
770 | list_for_each_entry(tmp_governor, &devfreq_governor_list, node) | |
771 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
772 | "%s ", tmp_governor->name); | |
773 | mutex_unlock(&devfreq_list_lock); | |
774 | ||
775 | /* Truncate the trailing space */ | |
776 | if (count) | |
777 | count--; | |
778 | ||
779 | count += sprintf(&buf[count], "\n"); | |
780 | ||
781 | return count; | |
782 | } | |
a93d6b0a | 783 | static DEVICE_ATTR_RO(available_governors); |
0359d1af | 784 | |
a93d6b0a GKH |
785 | static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, |
786 | char *buf) | |
7f98a905 RV |
787 | { |
788 | unsigned long freq; | |
789 | struct devfreq *devfreq = to_devfreq(dev); | |
790 | ||
791 | if (devfreq->profile->get_cur_freq && | |
792 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
793 | return sprintf(buf, "%lu\n", freq); | |
794 | ||
795 | return sprintf(buf, "%lu\n", devfreq->previous_freq); | |
796 | } | |
a93d6b0a | 797 | static DEVICE_ATTR_RO(cur_freq); |
7f98a905 | 798 | |
a93d6b0a GKH |
799 | static ssize_t target_freq_show(struct device *dev, |
800 | struct device_attribute *attr, char *buf) | |
9005b650 MH |
801 | { |
802 | return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); | |
803 | } | |
a93d6b0a | 804 | static DEVICE_ATTR_RO(target_freq); |
9005b650 | 805 | |
a93d6b0a | 806 | static ssize_t polling_interval_show(struct device *dev, |
9005b650 MH |
807 | struct device_attribute *attr, char *buf) |
808 | { | |
809 | return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); | |
810 | } | |
811 | ||
a93d6b0a | 812 | static ssize_t polling_interval_store(struct device *dev, |
9005b650 MH |
813 | struct device_attribute *attr, |
814 | const char *buf, size_t count) | |
815 | { | |
816 | struct devfreq *df = to_devfreq(dev); | |
817 | unsigned int value; | |
818 | int ret; | |
819 | ||
1b5c1be2 NM |
820 | if (!df->governor) |
821 | return -EINVAL; | |
822 | ||
9005b650 MH |
823 | ret = sscanf(buf, "%u", &value); |
824 | if (ret != 1) | |
12e26265 | 825 | return -EINVAL; |
9005b650 | 826 | |
7e6fdd4b | 827 | df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); |
9005b650 MH |
828 | ret = count; |
829 | ||
9005b650 MH |
830 | return ret; |
831 | } | |
a93d6b0a | 832 | static DEVICE_ATTR_RW(polling_interval); |
9005b650 | 833 | |
a93d6b0a | 834 | static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
835 | const char *buf, size_t count) |
836 | { | |
837 | struct devfreq *df = to_devfreq(dev); | |
838 | unsigned long value; | |
839 | int ret; | |
840 | unsigned long max; | |
841 | ||
842 | ret = sscanf(buf, "%lu", &value); | |
843 | if (ret != 1) | |
12e26265 | 844 | return -EINVAL; |
6530b9de MH |
845 | |
846 | mutex_lock(&df->lock); | |
847 | max = df->max_freq; | |
848 | if (value && max && value > max) { | |
849 | ret = -EINVAL; | |
850 | goto unlock; | |
851 | } | |
852 | ||
853 | df->min_freq = value; | |
854 | update_devfreq(df); | |
855 | ret = count; | |
856 | unlock: | |
857 | mutex_unlock(&df->lock); | |
6530b9de MH |
858 | return ret; |
859 | } | |
860 | ||
a93d6b0a | 861 | static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
862 | char *buf) |
863 | { | |
864 | return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); | |
865 | } | |
866 | ||
a93d6b0a | 867 | static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
868 | const char *buf, size_t count) |
869 | { | |
870 | struct devfreq *df = to_devfreq(dev); | |
871 | unsigned long value; | |
872 | int ret; | |
873 | unsigned long min; | |
874 | ||
875 | ret = sscanf(buf, "%lu", &value); | |
876 | if (ret != 1) | |
12e26265 | 877 | return -EINVAL; |
6530b9de MH |
878 | |
879 | mutex_lock(&df->lock); | |
880 | min = df->min_freq; | |
881 | if (value && min && value < min) { | |
882 | ret = -EINVAL; | |
883 | goto unlock; | |
884 | } | |
885 | ||
886 | df->max_freq = value; | |
887 | update_devfreq(df); | |
888 | ret = count; | |
889 | unlock: | |
890 | mutex_unlock(&df->lock); | |
6530b9de MH |
891 | return ret; |
892 | } | |
a93d6b0a | 893 | static DEVICE_ATTR_RW(min_freq); |
6530b9de | 894 | |
a93d6b0a | 895 | static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
896 | char *buf) |
897 | { | |
898 | return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); | |
899 | } | |
a93d6b0a | 900 | static DEVICE_ATTR_RW(max_freq); |
6530b9de | 901 | |
a93d6b0a GKH |
902 | static ssize_t available_frequencies_show(struct device *d, |
903 | struct device_attribute *attr, | |
904 | char *buf) | |
d287de85 NM |
905 | { |
906 | struct devfreq *df = to_devfreq(d); | |
907 | struct device *dev = df->dev.parent; | |
47d43ba7 | 908 | struct dev_pm_opp *opp; |
d287de85 NM |
909 | ssize_t count = 0; |
910 | unsigned long freq = 0; | |
911 | ||
912 | rcu_read_lock(); | |
913 | do { | |
5d4879cd | 914 | opp = dev_pm_opp_find_freq_ceil(dev, &freq); |
d287de85 NM |
915 | if (IS_ERR(opp)) |
916 | break; | |
917 | ||
918 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
919 | "%lu ", freq); | |
920 | freq++; | |
921 | } while (1); | |
922 | rcu_read_unlock(); | |
923 | ||
924 | /* Truncate the trailing space */ | |
925 | if (count) | |
926 | count--; | |
927 | ||
928 | count += sprintf(&buf[count], "\n"); | |
929 | ||
930 | return count; | |
931 | } | |
a93d6b0a | 932 | static DEVICE_ATTR_RO(available_frequencies); |
d287de85 | 933 | |
a93d6b0a GKH |
934 | static ssize_t trans_stat_show(struct device *dev, |
935 | struct device_attribute *attr, char *buf) | |
e552bbaf JL |
936 | { |
937 | struct devfreq *devfreq = to_devfreq(dev); | |
938 | ssize_t len; | |
39688ce6 | 939 | int i, j; |
e552bbaf JL |
940 | unsigned int max_state = devfreq->profile->max_state; |
941 | ||
39688ce6 RV |
942 | if (!devfreq->stop_polling && |
943 | devfreq_update_status(devfreq, devfreq->previous_freq)) | |
e552bbaf JL |
944 | return 0; |
945 | ||
946 | len = sprintf(buf, " From : To\n"); | |
947 | len += sprintf(buf + len, " :"); | |
948 | for (i = 0; i < max_state; i++) | |
949 | len += sprintf(buf + len, "%8u", | |
950 | devfreq->profile->freq_table[i]); | |
951 | ||
952 | len += sprintf(buf + len, " time(ms)\n"); | |
953 | ||
954 | for (i = 0; i < max_state; i++) { | |
955 | if (devfreq->profile->freq_table[i] | |
956 | == devfreq->previous_freq) { | |
957 | len += sprintf(buf + len, "*"); | |
958 | } else { | |
959 | len += sprintf(buf + len, " "); | |
960 | } | |
961 | len += sprintf(buf + len, "%8u:", | |
962 | devfreq->profile->freq_table[i]); | |
963 | for (j = 0; j < max_state; j++) | |
964 | len += sprintf(buf + len, "%8u", | |
965 | devfreq->trans_table[(i * max_state) + j]); | |
966 | len += sprintf(buf + len, "%10u\n", | |
967 | jiffies_to_msecs(devfreq->time_in_state[i])); | |
968 | } | |
969 | ||
970 | len += sprintf(buf + len, "Total transition : %u\n", | |
971 | devfreq->total_trans); | |
972 | return len; | |
973 | } | |
a93d6b0a GKH |
974 | static DEVICE_ATTR_RO(trans_stat); |
975 | ||
976 | static struct attribute *devfreq_attrs[] = { | |
977 | &dev_attr_governor.attr, | |
978 | &dev_attr_available_governors.attr, | |
979 | &dev_attr_cur_freq.attr, | |
980 | &dev_attr_available_frequencies.attr, | |
981 | &dev_attr_target_freq.attr, | |
982 | &dev_attr_polling_interval.attr, | |
983 | &dev_attr_min_freq.attr, | |
984 | &dev_attr_max_freq.attr, | |
985 | &dev_attr_trans_stat.attr, | |
986 | NULL, | |
9005b650 | 987 | }; |
a93d6b0a | 988 | ATTRIBUTE_GROUPS(devfreq); |
9005b650 | 989 | |
a3c98b8b MH |
990 | static int __init devfreq_init(void) |
991 | { | |
992 | devfreq_class = class_create(THIS_MODULE, "devfreq"); | |
993 | if (IS_ERR(devfreq_class)) { | |
994 | pr_err("%s: couldn't create class\n", __FILE__); | |
995 | return PTR_ERR(devfreq_class); | |
996 | } | |
7e6fdd4b RV |
997 | |
998 | devfreq_wq = create_freezable_workqueue("devfreq_wq"); | |
ea7f4548 | 999 | if (!devfreq_wq) { |
7e6fdd4b RV |
1000 | class_destroy(devfreq_class); |
1001 | pr_err("%s: couldn't create workqueue\n", __FILE__); | |
ea7f4548 | 1002 | return -ENOMEM; |
7e6fdd4b | 1003 | } |
a93d6b0a | 1004 | devfreq_class->dev_groups = devfreq_groups; |
7e6fdd4b | 1005 | |
a3c98b8b MH |
1006 | return 0; |
1007 | } | |
1008 | subsys_initcall(devfreq_init); | |
1009 | ||
1010 | static void __exit devfreq_exit(void) | |
1011 | { | |
1012 | class_destroy(devfreq_class); | |
7e6fdd4b | 1013 | destroy_workqueue(devfreq_wq); |
a3c98b8b MH |
1014 | } |
1015 | module_exit(devfreq_exit); | |
1016 | ||
1017 | /* | |
1018 | * The followings are helper functions for devfreq user device drivers with | |
1019 | * OPP framework. | |
1020 | */ | |
1021 | ||
1022 | /** | |
1023 | * devfreq_recommended_opp() - Helper function to get proper OPP for the | |
1024 | * freq value given to target callback. | |
c5b4a1c1 NM |
1025 | * @dev: The devfreq user device. (parent of devfreq) |
1026 | * @freq: The frequency given to target function | |
1027 | * @flags: Flags handed from devfreq framework. | |
a3c98b8b | 1028 | * |
bcb27549 NM |
1029 | * Locking: This function must be called under rcu_read_lock(). opp is a rcu |
1030 | * protected pointer. The reason for the same is that the opp pointer which is | |
1031 | * returned will remain valid for use with opp_get_{voltage, freq} only while | |
1032 | * under the locked area. The pointer returned must be used prior to unlocking | |
1033 | * with rcu_read_unlock() to maintain the integrity of the pointer. | |
a3c98b8b | 1034 | */ |
47d43ba7 NM |
1035 | struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, |
1036 | unsigned long *freq, | |
1037 | u32 flags) | |
a3c98b8b | 1038 | { |
47d43ba7 | 1039 | struct dev_pm_opp *opp; |
a3c98b8b | 1040 | |
ab5f299f MH |
1041 | if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { |
1042 | /* The freq is an upper bound. opp should be lower */ | |
5d4879cd | 1043 | opp = dev_pm_opp_find_freq_floor(dev, freq); |
ab5f299f MH |
1044 | |
1045 | /* If not available, use the closest opp */ | |
0779726c | 1046 | if (opp == ERR_PTR(-ERANGE)) |
5d4879cd | 1047 | opp = dev_pm_opp_find_freq_ceil(dev, freq); |
ab5f299f MH |
1048 | } else { |
1049 | /* The freq is an lower bound. opp should be higher */ | |
5d4879cd | 1050 | opp = dev_pm_opp_find_freq_ceil(dev, freq); |
ab5f299f MH |
1051 | |
1052 | /* If not available, use the closest opp */ | |
0779726c | 1053 | if (opp == ERR_PTR(-ERANGE)) |
5d4879cd | 1054 | opp = dev_pm_opp_find_freq_floor(dev, freq); |
ab5f299f MH |
1055 | } |
1056 | ||
a3c98b8b MH |
1057 | return opp; |
1058 | } | |
1059 | ||
1060 | /** | |
1061 | * devfreq_register_opp_notifier() - Helper function to get devfreq notified | |
1062 | * for any changes in the OPP availability | |
1063 | * changes | |
c5b4a1c1 NM |
1064 | * @dev: The devfreq user device. (parent of devfreq) |
1065 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
1066 | */ |
1067 | int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1068 | { | |
389baed0 MH |
1069 | struct srcu_notifier_head *nh; |
1070 | int ret = 0; | |
a3c98b8b | 1071 | |
389baed0 | 1072 | rcu_read_lock(); |
5d4879cd | 1073 | nh = dev_pm_opp_get_notifier(dev); |
a3c98b8b | 1074 | if (IS_ERR(nh)) |
389baed0 MH |
1075 | ret = PTR_ERR(nh); |
1076 | rcu_read_unlock(); | |
1077 | if (!ret) | |
1078 | ret = srcu_notifier_chain_register(nh, &devfreq->nb); | |
1079 | ||
1080 | return ret; | |
a3c98b8b MH |
1081 | } |
1082 | ||
1083 | /** | |
1084 | * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq | |
1085 | * notified for any changes in the OPP | |
1086 | * availability changes anymore. | |
c5b4a1c1 NM |
1087 | * @dev: The devfreq user device. (parent of devfreq) |
1088 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
1089 | * |
1090 | * At exit() callback of devfreq_dev_profile, this must be included if | |
1091 | * devfreq_recommended_opp is used. | |
1092 | */ | |
1093 | int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1094 | { | |
389baed0 MH |
1095 | struct srcu_notifier_head *nh; |
1096 | int ret = 0; | |
a3c98b8b | 1097 | |
389baed0 | 1098 | rcu_read_lock(); |
5d4879cd | 1099 | nh = dev_pm_opp_get_notifier(dev); |
a3c98b8b | 1100 | if (IS_ERR(nh)) |
389baed0 MH |
1101 | ret = PTR_ERR(nh); |
1102 | rcu_read_unlock(); | |
1103 | if (!ret) | |
1104 | ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); | |
1105 | ||
1106 | return ret; | |
a3c98b8b MH |
1107 | } |
1108 | ||
1109 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
1110 | MODULE_DESCRIPTION("devfreq class support"); | |
1111 | MODULE_LICENSE("GPL"); |