Commit | Line | Data |
---|---|---|
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 MH |
396 | */ |
397 | static void _remove_devfreq(struct devfreq *devfreq, bool skip) | |
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 MH |
415 | if (!skip && get_device(&devfreq->dev)) { |
416 | device_unregister(&devfreq->dev); | |
417 | put_device(&devfreq->dev); | |
418 | } | |
419 | ||
a3c98b8b | 420 | mutex_destroy(&devfreq->lock); |
a3c98b8b MH |
421 | kfree(devfreq); |
422 | } | |
423 | ||
424 | /** | |
425 | * devfreq_dev_release() - Callback for struct device to release the device. | |
426 | * @dev: the devfreq device | |
427 | * | |
428 | * This calls _remove_devfreq() if _remove_devfreq() is not called. | |
429 | * Note that devfreq_dev_release() could be called by _remove_devfreq() as | |
430 | * well as by others unregistering the device. | |
431 | */ | |
432 | static void devfreq_dev_release(struct device *dev) | |
433 | { | |
434 | struct devfreq *devfreq = to_devfreq(dev); | |
a3c98b8b | 435 | |
a3c98b8b | 436 | _remove_devfreq(devfreq, true); |
a3c98b8b MH |
437 | } |
438 | ||
439 | /** | |
440 | * devfreq_add_device() - Add devfreq feature to the device | |
441 | * @dev: the device to add devfreq feature. | |
442 | * @profile: device-specific profile to run devfreq. | |
1b5c1be2 | 443 | * @governor_name: name of the policy to choose frequency. |
a3c98b8b MH |
444 | * @data: private data for the governor. The devfreq framework does not |
445 | * touch this value. | |
446 | */ | |
447 | struct devfreq *devfreq_add_device(struct device *dev, | |
448 | struct devfreq_dev_profile *profile, | |
1b5c1be2 | 449 | const char *governor_name, |
a3c98b8b MH |
450 | void *data) |
451 | { | |
452 | struct devfreq *devfreq; | |
1b5c1be2 | 453 | struct devfreq_governor *governor; |
a3c98b8b MH |
454 | int err = 0; |
455 | ||
1b5c1be2 | 456 | if (!dev || !profile || !governor_name) { |
a3c98b8b MH |
457 | dev_err(dev, "%s: Invalid parameters.\n", __func__); |
458 | return ERR_PTR(-EINVAL); | |
459 | } | |
460 | ||
7e6fdd4b RV |
461 | mutex_lock(&devfreq_list_lock); |
462 | devfreq = find_device_devfreq(dev); | |
463 | mutex_unlock(&devfreq_list_lock); | |
464 | if (!IS_ERR(devfreq)) { | |
465 | dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__); | |
466 | err = -EINVAL; | |
467 | goto err_out; | |
a3c98b8b MH |
468 | } |
469 | ||
470 | devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); | |
471 | if (!devfreq) { | |
472 | dev_err(dev, "%s: Unable to create devfreq for the device\n", | |
473 | __func__); | |
474 | err = -ENOMEM; | |
3f19f08a | 475 | goto err_out; |
a3c98b8b MH |
476 | } |
477 | ||
478 | mutex_init(&devfreq->lock); | |
479 | mutex_lock(&devfreq->lock); | |
480 | devfreq->dev.parent = dev; | |
481 | devfreq->dev.class = devfreq_class; | |
482 | devfreq->dev.release = devfreq_dev_release; | |
483 | devfreq->profile = profile; | |
1b5c1be2 | 484 | strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); |
a3c98b8b MH |
485 | devfreq->previous_freq = profile->initial_freq; |
486 | devfreq->data = data; | |
a3c98b8b MH |
487 | devfreq->nb.notifier_call = devfreq_notifier_call; |
488 | ||
e552bbaf JL |
489 | devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * |
490 | devfreq->profile->max_state * | |
491 | devfreq->profile->max_state, | |
492 | GFP_KERNEL); | |
493 | devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) * | |
494 | devfreq->profile->max_state, | |
495 | GFP_KERNEL); | |
496 | devfreq->last_stat_updated = jiffies; | |
497 | ||
02aa2a37 | 498 | dev_set_name(&devfreq->dev, "%s", dev_name(dev)); |
a3c98b8b MH |
499 | err = device_register(&devfreq->dev); |
500 | if (err) { | |
501 | put_device(&devfreq->dev); | |
7e6fdd4b | 502 | mutex_unlock(&devfreq->lock); |
a3c98b8b MH |
503 | goto err_dev; |
504 | } | |
505 | ||
a3c98b8b MH |
506 | mutex_unlock(&devfreq->lock); |
507 | ||
a3c98b8b | 508 | mutex_lock(&devfreq_list_lock); |
a3c98b8b MH |
509 | list_add(&devfreq->node, &devfreq_list); |
510 | ||
1b5c1be2 NM |
511 | governor = find_devfreq_governor(devfreq->governor_name); |
512 | if (!IS_ERR(governor)) | |
513 | devfreq->governor = governor; | |
514 | if (devfreq->governor) | |
515 | err = devfreq->governor->event_handler(devfreq, | |
516 | DEVFREQ_GOV_START, NULL); | |
a3c98b8b | 517 | mutex_unlock(&devfreq_list_lock); |
7e6fdd4b RV |
518 | if (err) { |
519 | dev_err(dev, "%s: Unable to start governor for the device\n", | |
520 | __func__); | |
521 | goto err_init; | |
a3c98b8b | 522 | } |
7e6fdd4b | 523 | |
3f19f08a AL |
524 | return devfreq; |
525 | ||
a3c98b8b | 526 | err_init: |
7e6fdd4b | 527 | list_del(&devfreq->node); |
a3c98b8b MH |
528 | device_unregister(&devfreq->dev); |
529 | err_dev: | |
a3c98b8b | 530 | kfree(devfreq); |
3f19f08a AL |
531 | err_out: |
532 | return ERR_PTR(err); | |
a3c98b8b | 533 | } |
7e6fdd4b | 534 | EXPORT_SYMBOL(devfreq_add_device); |
a3c98b8b MH |
535 | |
536 | /** | |
537 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
c5b4a1c1 | 538 | * @devfreq: the devfreq instance to be removed |
de9c7394 MH |
539 | * |
540 | * The opposite of devfreq_add_device(). | |
a3c98b8b MH |
541 | */ |
542 | int devfreq_remove_device(struct devfreq *devfreq) | |
543 | { | |
544 | if (!devfreq) | |
545 | return -EINVAL; | |
546 | ||
7e6fdd4b | 547 | _remove_devfreq(devfreq, false); |
9f3bdd4f | 548 | |
a3c98b8b MH |
549 | return 0; |
550 | } | |
7e6fdd4b | 551 | EXPORT_SYMBOL(devfreq_remove_device); |
a3c98b8b | 552 | |
206c30cf RV |
553 | /** |
554 | * devfreq_suspend_device() - Suspend devfreq of a device. | |
555 | * @devfreq: the devfreq instance to be suspended | |
de9c7394 MH |
556 | * |
557 | * This function is intended to be called by the pm callbacks | |
558 | * (e.g., runtime_suspend, suspend) of the device driver that | |
559 | * holds the devfreq. | |
206c30cf RV |
560 | */ |
561 | int devfreq_suspend_device(struct devfreq *devfreq) | |
562 | { | |
a3c98b8b MH |
563 | if (!devfreq) |
564 | return -EINVAL; | |
565 | ||
1b5c1be2 NM |
566 | if (!devfreq->governor) |
567 | return 0; | |
568 | ||
206c30cf RV |
569 | return devfreq->governor->event_handler(devfreq, |
570 | DEVFREQ_GOV_SUSPEND, NULL); | |
571 | } | |
572 | EXPORT_SYMBOL(devfreq_suspend_device); | |
573 | ||
574 | /** | |
575 | * devfreq_resume_device() - Resume devfreq of a device. | |
576 | * @devfreq: the devfreq instance to be resumed | |
de9c7394 MH |
577 | * |
578 | * This function is intended to be called by the pm callbacks | |
579 | * (e.g., runtime_resume, resume) of the device driver that | |
580 | * holds the devfreq. | |
206c30cf RV |
581 | */ |
582 | int devfreq_resume_device(struct devfreq *devfreq) | |
583 | { | |
584 | if (!devfreq) | |
585 | return -EINVAL; | |
586 | ||
1b5c1be2 NM |
587 | if (!devfreq->governor) |
588 | return 0; | |
589 | ||
206c30cf RV |
590 | return devfreq->governor->event_handler(devfreq, |
591 | DEVFREQ_GOV_RESUME, NULL); | |
592 | } | |
593 | EXPORT_SYMBOL(devfreq_resume_device); | |
594 | ||
3aa173b8 NM |
595 | /** |
596 | * devfreq_add_governor() - Add devfreq governor | |
597 | * @governor: the devfreq governor to be added | |
598 | */ | |
599 | int devfreq_add_governor(struct devfreq_governor *governor) | |
600 | { | |
601 | struct devfreq_governor *g; | |
1b5c1be2 | 602 | struct devfreq *devfreq; |
3aa173b8 NM |
603 | int err = 0; |
604 | ||
605 | if (!governor) { | |
606 | pr_err("%s: Invalid parameters.\n", __func__); | |
607 | return -EINVAL; | |
608 | } | |
609 | ||
610 | mutex_lock(&devfreq_list_lock); | |
611 | g = find_devfreq_governor(governor->name); | |
612 | if (!IS_ERR(g)) { | |
613 | pr_err("%s: governor %s already registered\n", __func__, | |
614 | g->name); | |
615 | err = -EINVAL; | |
616 | goto err_out; | |
617 | } | |
9f3bdd4f | 618 | |
3aa173b8 NM |
619 | list_add(&governor->node, &devfreq_governor_list); |
620 | ||
1b5c1be2 NM |
621 | list_for_each_entry(devfreq, &devfreq_list, node) { |
622 | int ret = 0; | |
623 | struct device *dev = devfreq->dev.parent; | |
624 | ||
625 | if (!strncmp(devfreq->governor_name, governor->name, | |
626 | DEVFREQ_NAME_LEN)) { | |
627 | /* The following should never occur */ | |
628 | if (devfreq->governor) { | |
629 | dev_warn(dev, | |
630 | "%s: Governor %s already present\n", | |
631 | __func__, devfreq->governor->name); | |
632 | ret = devfreq->governor->event_handler(devfreq, | |
633 | DEVFREQ_GOV_STOP, NULL); | |
634 | if (ret) { | |
635 | dev_warn(dev, | |
636 | "%s: Governor %s stop = %d\n", | |
637 | __func__, | |
638 | devfreq->governor->name, ret); | |
639 | } | |
640 | /* Fall through */ | |
641 | } | |
642 | devfreq->governor = governor; | |
643 | ret = devfreq->governor->event_handler(devfreq, | |
644 | DEVFREQ_GOV_START, NULL); | |
645 | if (ret) { | |
646 | dev_warn(dev, "%s: Governor %s start=%d\n", | |
647 | __func__, devfreq->governor->name, | |
648 | ret); | |
649 | } | |
a3c98b8b MH |
650 | } |
651 | } | |
652 | ||
3aa173b8 NM |
653 | err_out: |
654 | mutex_unlock(&devfreq_list_lock); | |
a3c98b8b | 655 | |
3aa173b8 NM |
656 | return err; |
657 | } | |
658 | EXPORT_SYMBOL(devfreq_add_governor); | |
a3c98b8b | 659 | |
3aa173b8 NM |
660 | /** |
661 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
662 | * @governor: the devfreq governor to be removed | |
663 | */ | |
664 | int devfreq_remove_governor(struct devfreq_governor *governor) | |
665 | { | |
666 | struct devfreq_governor *g; | |
1b5c1be2 | 667 | struct devfreq *devfreq; |
3aa173b8 NM |
668 | int err = 0; |
669 | ||
670 | if (!governor) { | |
671 | pr_err("%s: Invalid parameters.\n", __func__); | |
672 | return -EINVAL; | |
673 | } | |
674 | ||
675 | mutex_lock(&devfreq_list_lock); | |
676 | g = find_devfreq_governor(governor->name); | |
677 | if (IS_ERR(g)) { | |
678 | pr_err("%s: governor %s not registered\n", __func__, | |
b9e1c8e8 | 679 | governor->name); |
f9c08e2a | 680 | err = PTR_ERR(g); |
3aa173b8 NM |
681 | goto err_out; |
682 | } | |
1b5c1be2 NM |
683 | list_for_each_entry(devfreq, &devfreq_list, node) { |
684 | int ret; | |
685 | struct device *dev = devfreq->dev.parent; | |
686 | ||
687 | if (!strncmp(devfreq->governor_name, governor->name, | |
688 | DEVFREQ_NAME_LEN)) { | |
689 | /* we should have a devfreq governor! */ | |
690 | if (!devfreq->governor) { | |
691 | dev_warn(dev, "%s: Governor %s NOT present\n", | |
692 | __func__, governor->name); | |
693 | continue; | |
694 | /* Fall through */ | |
695 | } | |
696 | ret = devfreq->governor->event_handler(devfreq, | |
697 | DEVFREQ_GOV_STOP, NULL); | |
698 | if (ret) { | |
699 | dev_warn(dev, "%s: Governor %s stop=%d\n", | |
700 | __func__, devfreq->governor->name, | |
701 | ret); | |
702 | } | |
703 | devfreq->governor = NULL; | |
704 | } | |
705 | } | |
3aa173b8 NM |
706 | |
707 | list_del(&governor->node); | |
708 | err_out: | |
709 | mutex_unlock(&devfreq_list_lock); | |
710 | ||
711 | return err; | |
a3c98b8b | 712 | } |
3aa173b8 | 713 | EXPORT_SYMBOL(devfreq_remove_governor); |
a3c98b8b | 714 | |
a93d6b0a | 715 | static ssize_t governor_show(struct device *dev, |
9005b650 MH |
716 | struct device_attribute *attr, char *buf) |
717 | { | |
1b5c1be2 NM |
718 | if (!to_devfreq(dev)->governor) |
719 | return -EINVAL; | |
720 | ||
9005b650 MH |
721 | return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); |
722 | } | |
723 | ||
a93d6b0a | 724 | static ssize_t governor_store(struct device *dev, struct device_attribute *attr, |
0359d1af NM |
725 | const char *buf, size_t count) |
726 | { | |
727 | struct devfreq *df = to_devfreq(dev); | |
728 | int ret; | |
729 | char str_governor[DEVFREQ_NAME_LEN + 1]; | |
730 | struct devfreq_governor *governor; | |
731 | ||
732 | ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); | |
733 | if (ret != 1) | |
734 | return -EINVAL; | |
735 | ||
736 | mutex_lock(&devfreq_list_lock); | |
737 | governor = find_devfreq_governor(str_governor); | |
738 | if (IS_ERR(governor)) { | |
739 | ret = PTR_ERR(governor); | |
740 | goto out; | |
741 | } | |
742 | if (df->governor == governor) | |
743 | goto out; | |
744 | ||
745 | if (df->governor) { | |
746 | ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); | |
747 | if (ret) { | |
748 | dev_warn(dev, "%s: Governor %s not stopped(%d)\n", | |
749 | __func__, df->governor->name, ret); | |
750 | goto out; | |
751 | } | |
752 | } | |
753 | df->governor = governor; | |
754 | strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); | |
755 | ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); | |
756 | if (ret) | |
757 | dev_warn(dev, "%s: Governor %s not started(%d)\n", | |
758 | __func__, df->governor->name, ret); | |
759 | out: | |
760 | mutex_unlock(&devfreq_list_lock); | |
761 | ||
762 | if (!ret) | |
763 | ret = count; | |
764 | return ret; | |
765 | } | |
a93d6b0a GKH |
766 | static DEVICE_ATTR_RW(governor); |
767 | ||
768 | static ssize_t available_governors_show(struct device *d, | |
769 | struct device_attribute *attr, | |
770 | char *buf) | |
50a5b33e NM |
771 | { |
772 | struct devfreq_governor *tmp_governor; | |
773 | ssize_t count = 0; | |
774 | ||
775 | mutex_lock(&devfreq_list_lock); | |
776 | list_for_each_entry(tmp_governor, &devfreq_governor_list, node) | |
777 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
778 | "%s ", tmp_governor->name); | |
779 | mutex_unlock(&devfreq_list_lock); | |
780 | ||
781 | /* Truncate the trailing space */ | |
782 | if (count) | |
783 | count--; | |
784 | ||
785 | count += sprintf(&buf[count], "\n"); | |
786 | ||
787 | return count; | |
788 | } | |
a93d6b0a | 789 | static DEVICE_ATTR_RO(available_governors); |
0359d1af | 790 | |
a93d6b0a GKH |
791 | static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, |
792 | char *buf) | |
7f98a905 RV |
793 | { |
794 | unsigned long freq; | |
795 | struct devfreq *devfreq = to_devfreq(dev); | |
796 | ||
797 | if (devfreq->profile->get_cur_freq && | |
798 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
799 | return sprintf(buf, "%lu\n", freq); | |
800 | ||
801 | return sprintf(buf, "%lu\n", devfreq->previous_freq); | |
802 | } | |
a93d6b0a | 803 | static DEVICE_ATTR_RO(cur_freq); |
7f98a905 | 804 | |
a93d6b0a GKH |
805 | static ssize_t target_freq_show(struct device *dev, |
806 | struct device_attribute *attr, char *buf) | |
9005b650 MH |
807 | { |
808 | return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); | |
809 | } | |
a93d6b0a | 810 | static DEVICE_ATTR_RO(target_freq); |
9005b650 | 811 | |
a93d6b0a | 812 | static ssize_t polling_interval_show(struct device *dev, |
9005b650 MH |
813 | struct device_attribute *attr, char *buf) |
814 | { | |
815 | return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); | |
816 | } | |
817 | ||
a93d6b0a | 818 | static ssize_t polling_interval_store(struct device *dev, |
9005b650 MH |
819 | struct device_attribute *attr, |
820 | const char *buf, size_t count) | |
821 | { | |
822 | struct devfreq *df = to_devfreq(dev); | |
823 | unsigned int value; | |
824 | int ret; | |
825 | ||
1b5c1be2 NM |
826 | if (!df->governor) |
827 | return -EINVAL; | |
828 | ||
9005b650 MH |
829 | ret = sscanf(buf, "%u", &value); |
830 | if (ret != 1) | |
12e26265 | 831 | return -EINVAL; |
9005b650 | 832 | |
7e6fdd4b | 833 | df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); |
9005b650 MH |
834 | ret = count; |
835 | ||
9005b650 MH |
836 | return ret; |
837 | } | |
a93d6b0a | 838 | static DEVICE_ATTR_RW(polling_interval); |
9005b650 | 839 | |
a93d6b0a | 840 | static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
841 | const char *buf, size_t count) |
842 | { | |
843 | struct devfreq *df = to_devfreq(dev); | |
844 | unsigned long value; | |
845 | int ret; | |
846 | unsigned long max; | |
847 | ||
848 | ret = sscanf(buf, "%lu", &value); | |
849 | if (ret != 1) | |
12e26265 | 850 | return -EINVAL; |
6530b9de MH |
851 | |
852 | mutex_lock(&df->lock); | |
853 | max = df->max_freq; | |
854 | if (value && max && value > max) { | |
855 | ret = -EINVAL; | |
856 | goto unlock; | |
857 | } | |
858 | ||
859 | df->min_freq = value; | |
860 | update_devfreq(df); | |
861 | ret = count; | |
862 | unlock: | |
863 | mutex_unlock(&df->lock); | |
6530b9de MH |
864 | return ret; |
865 | } | |
866 | ||
a93d6b0a | 867 | static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
868 | char *buf) |
869 | { | |
870 | return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); | |
871 | } | |
872 | ||
a93d6b0a | 873 | static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
874 | const char *buf, size_t count) |
875 | { | |
876 | struct devfreq *df = to_devfreq(dev); | |
877 | unsigned long value; | |
878 | int ret; | |
879 | unsigned long min; | |
880 | ||
881 | ret = sscanf(buf, "%lu", &value); | |
882 | if (ret != 1) | |
12e26265 | 883 | return -EINVAL; |
6530b9de MH |
884 | |
885 | mutex_lock(&df->lock); | |
886 | min = df->min_freq; | |
887 | if (value && min && value < min) { | |
888 | ret = -EINVAL; | |
889 | goto unlock; | |
890 | } | |
891 | ||
892 | df->max_freq = value; | |
893 | update_devfreq(df); | |
894 | ret = count; | |
895 | unlock: | |
896 | mutex_unlock(&df->lock); | |
6530b9de MH |
897 | return ret; |
898 | } | |
a93d6b0a | 899 | static DEVICE_ATTR_RW(min_freq); |
6530b9de | 900 | |
a93d6b0a | 901 | static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
902 | char *buf) |
903 | { | |
904 | return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); | |
905 | } | |
a93d6b0a | 906 | static DEVICE_ATTR_RW(max_freq); |
6530b9de | 907 | |
a93d6b0a GKH |
908 | static ssize_t available_frequencies_show(struct device *d, |
909 | struct device_attribute *attr, | |
910 | char *buf) | |
d287de85 NM |
911 | { |
912 | struct devfreq *df = to_devfreq(d); | |
913 | struct device *dev = df->dev.parent; | |
47d43ba7 | 914 | struct dev_pm_opp *opp; |
d287de85 NM |
915 | ssize_t count = 0; |
916 | unsigned long freq = 0; | |
917 | ||
918 | rcu_read_lock(); | |
919 | do { | |
5d4879cd | 920 | opp = dev_pm_opp_find_freq_ceil(dev, &freq); |
d287de85 NM |
921 | if (IS_ERR(opp)) |
922 | break; | |
923 | ||
924 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
925 | "%lu ", freq); | |
926 | freq++; | |
927 | } while (1); | |
928 | rcu_read_unlock(); | |
929 | ||
930 | /* Truncate the trailing space */ | |
931 | if (count) | |
932 | count--; | |
933 | ||
934 | count += sprintf(&buf[count], "\n"); | |
935 | ||
936 | return count; | |
937 | } | |
a93d6b0a | 938 | static DEVICE_ATTR_RO(available_frequencies); |
d287de85 | 939 | |
a93d6b0a GKH |
940 | static ssize_t trans_stat_show(struct device *dev, |
941 | struct device_attribute *attr, char *buf) | |
e552bbaf JL |
942 | { |
943 | struct devfreq *devfreq = to_devfreq(dev); | |
944 | ssize_t len; | |
39688ce6 | 945 | int i, j; |
e552bbaf JL |
946 | unsigned int max_state = devfreq->profile->max_state; |
947 | ||
39688ce6 RV |
948 | if (!devfreq->stop_polling && |
949 | devfreq_update_status(devfreq, devfreq->previous_freq)) | |
e552bbaf JL |
950 | return 0; |
951 | ||
952 | len = sprintf(buf, " From : To\n"); | |
953 | len += sprintf(buf + len, " :"); | |
954 | for (i = 0; i < max_state; i++) | |
955 | len += sprintf(buf + len, "%8u", | |
956 | devfreq->profile->freq_table[i]); | |
957 | ||
958 | len += sprintf(buf + len, " time(ms)\n"); | |
959 | ||
960 | for (i = 0; i < max_state; i++) { | |
961 | if (devfreq->profile->freq_table[i] | |
962 | == devfreq->previous_freq) { | |
963 | len += sprintf(buf + len, "*"); | |
964 | } else { | |
965 | len += sprintf(buf + len, " "); | |
966 | } | |
967 | len += sprintf(buf + len, "%8u:", | |
968 | devfreq->profile->freq_table[i]); | |
969 | for (j = 0; j < max_state; j++) | |
970 | len += sprintf(buf + len, "%8u", | |
971 | devfreq->trans_table[(i * max_state) + j]); | |
972 | len += sprintf(buf + len, "%10u\n", | |
973 | jiffies_to_msecs(devfreq->time_in_state[i])); | |
974 | } | |
975 | ||
976 | len += sprintf(buf + len, "Total transition : %u\n", | |
977 | devfreq->total_trans); | |
978 | return len; | |
979 | } | |
a93d6b0a GKH |
980 | static DEVICE_ATTR_RO(trans_stat); |
981 | ||
982 | static struct attribute *devfreq_attrs[] = { | |
983 | &dev_attr_governor.attr, | |
984 | &dev_attr_available_governors.attr, | |
985 | &dev_attr_cur_freq.attr, | |
986 | &dev_attr_available_frequencies.attr, | |
987 | &dev_attr_target_freq.attr, | |
988 | &dev_attr_polling_interval.attr, | |
989 | &dev_attr_min_freq.attr, | |
990 | &dev_attr_max_freq.attr, | |
991 | &dev_attr_trans_stat.attr, | |
992 | NULL, | |
9005b650 | 993 | }; |
a93d6b0a | 994 | ATTRIBUTE_GROUPS(devfreq); |
9005b650 | 995 | |
a3c98b8b MH |
996 | static int __init devfreq_init(void) |
997 | { | |
998 | devfreq_class = class_create(THIS_MODULE, "devfreq"); | |
999 | if (IS_ERR(devfreq_class)) { | |
1000 | pr_err("%s: couldn't create class\n", __FILE__); | |
1001 | return PTR_ERR(devfreq_class); | |
1002 | } | |
7e6fdd4b RV |
1003 | |
1004 | devfreq_wq = create_freezable_workqueue("devfreq_wq"); | |
ea7f4548 | 1005 | if (!devfreq_wq) { |
7e6fdd4b RV |
1006 | class_destroy(devfreq_class); |
1007 | pr_err("%s: couldn't create workqueue\n", __FILE__); | |
ea7f4548 | 1008 | return -ENOMEM; |
7e6fdd4b | 1009 | } |
a93d6b0a | 1010 | devfreq_class->dev_groups = devfreq_groups; |
7e6fdd4b | 1011 | |
a3c98b8b MH |
1012 | return 0; |
1013 | } | |
1014 | subsys_initcall(devfreq_init); | |
1015 | ||
1016 | static void __exit devfreq_exit(void) | |
1017 | { | |
1018 | class_destroy(devfreq_class); | |
7e6fdd4b | 1019 | destroy_workqueue(devfreq_wq); |
a3c98b8b MH |
1020 | } |
1021 | module_exit(devfreq_exit); | |
1022 | ||
1023 | /* | |
1024 | * The followings are helper functions for devfreq user device drivers with | |
1025 | * OPP framework. | |
1026 | */ | |
1027 | ||
1028 | /** | |
1029 | * devfreq_recommended_opp() - Helper function to get proper OPP for the | |
1030 | * freq value given to target callback. | |
c5b4a1c1 NM |
1031 | * @dev: The devfreq user device. (parent of devfreq) |
1032 | * @freq: The frequency given to target function | |
1033 | * @flags: Flags handed from devfreq framework. | |
a3c98b8b | 1034 | * |
bcb27549 NM |
1035 | * Locking: This function must be called under rcu_read_lock(). opp is a rcu |
1036 | * protected pointer. The reason for the same is that the opp pointer which is | |
1037 | * returned will remain valid for use with opp_get_{voltage, freq} only while | |
1038 | * under the locked area. The pointer returned must be used prior to unlocking | |
1039 | * with rcu_read_unlock() to maintain the integrity of the pointer. | |
a3c98b8b | 1040 | */ |
47d43ba7 NM |
1041 | struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, |
1042 | unsigned long *freq, | |
1043 | u32 flags) | |
a3c98b8b | 1044 | { |
47d43ba7 | 1045 | struct dev_pm_opp *opp; |
a3c98b8b | 1046 | |
ab5f299f MH |
1047 | if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { |
1048 | /* The freq is an upper bound. opp should be lower */ | |
5d4879cd | 1049 | opp = dev_pm_opp_find_freq_floor(dev, freq); |
ab5f299f MH |
1050 | |
1051 | /* If not available, use the closest opp */ | |
0779726c | 1052 | if (opp == ERR_PTR(-ERANGE)) |
5d4879cd | 1053 | opp = dev_pm_opp_find_freq_ceil(dev, freq); |
ab5f299f MH |
1054 | } else { |
1055 | /* The freq is an lower bound. opp should be higher */ | |
5d4879cd | 1056 | opp = dev_pm_opp_find_freq_ceil(dev, freq); |
ab5f299f MH |
1057 | |
1058 | /* If not available, use the closest opp */ | |
0779726c | 1059 | if (opp == ERR_PTR(-ERANGE)) |
5d4879cd | 1060 | opp = dev_pm_opp_find_freq_floor(dev, freq); |
ab5f299f MH |
1061 | } |
1062 | ||
a3c98b8b MH |
1063 | return opp; |
1064 | } | |
1065 | ||
1066 | /** | |
1067 | * devfreq_register_opp_notifier() - Helper function to get devfreq notified | |
1068 | * for any changes in the OPP availability | |
1069 | * changes | |
c5b4a1c1 NM |
1070 | * @dev: The devfreq user device. (parent of devfreq) |
1071 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
1072 | */ |
1073 | int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1074 | { | |
389baed0 MH |
1075 | struct srcu_notifier_head *nh; |
1076 | int ret = 0; | |
a3c98b8b | 1077 | |
389baed0 | 1078 | rcu_read_lock(); |
5d4879cd | 1079 | nh = dev_pm_opp_get_notifier(dev); |
a3c98b8b | 1080 | if (IS_ERR(nh)) |
389baed0 MH |
1081 | ret = PTR_ERR(nh); |
1082 | rcu_read_unlock(); | |
1083 | if (!ret) | |
1084 | ret = srcu_notifier_chain_register(nh, &devfreq->nb); | |
1085 | ||
1086 | return ret; | |
a3c98b8b MH |
1087 | } |
1088 | ||
1089 | /** | |
1090 | * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq | |
1091 | * notified for any changes in the OPP | |
1092 | * availability changes anymore. | |
c5b4a1c1 NM |
1093 | * @dev: The devfreq user device. (parent of devfreq) |
1094 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
1095 | * |
1096 | * At exit() callback of devfreq_dev_profile, this must be included if | |
1097 | * devfreq_recommended_opp is used. | |
1098 | */ | |
1099 | int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1100 | { | |
389baed0 MH |
1101 | struct srcu_notifier_head *nh; |
1102 | int ret = 0; | |
a3c98b8b | 1103 | |
389baed0 | 1104 | rcu_read_lock(); |
5d4879cd | 1105 | nh = dev_pm_opp_get_notifier(dev); |
a3c98b8b | 1106 | if (IS_ERR(nh)) |
389baed0 MH |
1107 | ret = PTR_ERR(nh); |
1108 | rcu_read_unlock(); | |
1109 | if (!ret) | |
1110 | ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); | |
1111 | ||
1112 | return ret; | |
a3c98b8b MH |
1113 | } |
1114 | ||
1115 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
1116 | MODULE_DESCRIPTION("devfreq class support"); | |
1117 | MODULE_LICENSE("GPL"); |