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 | ||
9348da2f | 56 | if (IS_ERR_OR_NULL(dev)) { |
a3c98b8b MH |
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 | ||
9348da2f | 136 | if (IS_ERR_OR_NULL(name)) { |
3aa173b8 NM |
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 | 179 | /* |
d3b7e174 | 180 | * Adjust the frequency with user freq and QoS. |
ab5f299f | 181 | * |
d3b7e174 JM |
182 | * List from the highest priority |
183 | * max_freq | |
ab5f299f MH |
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 | 394 | * @devfreq: the devfreq struct |
a3c98b8b | 395 | */ |
585fc83e | 396 | static void _remove_devfreq(struct devfreq *devfreq) |
a3c98b8b | 397 | { |
7e6fdd4b RV |
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"); | |
a3c98b8b MH |
402 | return; |
403 | } | |
7e6fdd4b RV |
404 | list_del(&devfreq->node); |
405 | mutex_unlock(&devfreq_list_lock); | |
a3c98b8b | 406 | |
1b5c1be2 NM |
407 | if (devfreq->governor) |
408 | devfreq->governor->event_handler(devfreq, | |
409 | DEVFREQ_GOV_STOP, NULL); | |
a3c98b8b MH |
410 | |
411 | if (devfreq->profile->exit) | |
412 | devfreq->profile->exit(devfreq->dev.parent); | |
413 | ||
a3c98b8b | 414 | mutex_destroy(&devfreq->lock); |
a3c98b8b MH |
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. | |
a3c98b8b MH |
423 | */ |
424 | static void devfreq_dev_release(struct device *dev) | |
425 | { | |
426 | struct devfreq *devfreq = to_devfreq(dev); | |
a3c98b8b | 427 | |
585fc83e | 428 | _remove_devfreq(devfreq); |
a3c98b8b MH |
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. | |
1b5c1be2 | 435 | * @governor_name: name of the policy to choose frequency. |
a3c98b8b MH |
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, | |
1b5c1be2 | 441 | const char *governor_name, |
a3c98b8b MH |
442 | void *data) |
443 | { | |
444 | struct devfreq *devfreq; | |
1b5c1be2 | 445 | struct devfreq_governor *governor; |
a3c98b8b MH |
446 | int err = 0; |
447 | ||
1b5c1be2 | 448 | if (!dev || !profile || !governor_name) { |
a3c98b8b MH |
449 | dev_err(dev, "%s: Invalid parameters.\n", __func__); |
450 | return ERR_PTR(-EINVAL); | |
451 | } | |
452 | ||
7e6fdd4b RV |
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; | |
a3c98b8b MH |
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; | |
3f19f08a | 467 | goto err_out; |
a3c98b8b MH |
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; | |
1b5c1be2 | 476 | strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); |
a3c98b8b MH |
477 | devfreq->previous_freq = profile->initial_freq; |
478 | devfreq->data = data; | |
a3c98b8b MH |
479 | devfreq->nb.notifier_call = devfreq_notifier_call; |
480 | ||
e552bbaf JL |
481 | devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * |
482 | devfreq->profile->max_state * | |
483 | devfreq->profile->max_state, | |
484 | GFP_KERNEL); | |
5f25f066 | 485 | devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned long) * |
e552bbaf JL |
486 | devfreq->profile->max_state, |
487 | GFP_KERNEL); | |
488 | devfreq->last_stat_updated = jiffies; | |
489 | ||
02aa2a37 | 490 | dev_set_name(&devfreq->dev, "%s", dev_name(dev)); |
a3c98b8b MH |
491 | err = device_register(&devfreq->dev); |
492 | if (err) { | |
493 | put_device(&devfreq->dev); | |
7e6fdd4b | 494 | mutex_unlock(&devfreq->lock); |
6d3cbfa7 | 495 | goto err_out; |
a3c98b8b MH |
496 | } |
497 | ||
a3c98b8b MH |
498 | mutex_unlock(&devfreq->lock); |
499 | ||
a3c98b8b | 500 | mutex_lock(&devfreq_list_lock); |
a3c98b8b MH |
501 | list_add(&devfreq->node, &devfreq_list); |
502 | ||
1b5c1be2 NM |
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); | |
a3c98b8b | 509 | mutex_unlock(&devfreq_list_lock); |
7e6fdd4b RV |
510 | if (err) { |
511 | dev_err(dev, "%s: Unable to start governor for the device\n", | |
512 | __func__); | |
513 | goto err_init; | |
a3c98b8b | 514 | } |
7e6fdd4b | 515 | |
3f19f08a AL |
516 | return devfreq; |
517 | ||
a3c98b8b | 518 | err_init: |
7e6fdd4b | 519 | list_del(&devfreq->node); |
a3c98b8b | 520 | device_unregister(&devfreq->dev); |
a3c98b8b | 521 | kfree(devfreq); |
3f19f08a AL |
522 | err_out: |
523 | return ERR_PTR(err); | |
a3c98b8b | 524 | } |
7e6fdd4b | 525 | EXPORT_SYMBOL(devfreq_add_device); |
a3c98b8b MH |
526 | |
527 | /** | |
528 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
c5b4a1c1 | 529 | * @devfreq: the devfreq instance to be removed |
de9c7394 MH |
530 | * |
531 | * The opposite of devfreq_add_device(). | |
a3c98b8b MH |
532 | */ |
533 | int devfreq_remove_device(struct devfreq *devfreq) | |
534 | { | |
535 | if (!devfreq) | |
536 | return -EINVAL; | |
537 | ||
585fc83e CC |
538 | device_unregister(&devfreq->dev); |
539 | put_device(&devfreq->dev); | |
9f3bdd4f | 540 | |
a3c98b8b MH |
541 | return 0; |
542 | } | |
7e6fdd4b | 543 | EXPORT_SYMBOL(devfreq_remove_device); |
a3c98b8b | 544 | |
8cd84092 CC |
545 | static int devm_devfreq_dev_match(struct device *dev, void *res, void *data) |
546 | { | |
547 | struct devfreq **r = res; | |
548 | ||
549 | if (WARN_ON(!r || !*r)) | |
550 | return 0; | |
551 | ||
552 | return *r == data; | |
553 | } | |
554 | ||
555 | static void devm_devfreq_dev_release(struct device *dev, void *res) | |
556 | { | |
557 | devfreq_remove_device(*(struct devfreq **)res); | |
558 | } | |
559 | ||
560 | /** | |
561 | * devm_devfreq_add_device() - Resource-managed devfreq_add_device() | |
562 | * @dev: the device to add devfreq feature. | |
563 | * @profile: device-specific profile to run devfreq. | |
564 | * @governor_name: name of the policy to choose frequency. | |
565 | * @data: private data for the governor. The devfreq framework does not | |
566 | * touch this value. | |
567 | * | |
568 | * This function manages automatically the memory of devfreq device using device | |
569 | * resource management and simplify the free operation for memory of devfreq | |
570 | * device. | |
571 | */ | |
572 | struct devfreq *devm_devfreq_add_device(struct device *dev, | |
573 | struct devfreq_dev_profile *profile, | |
574 | const char *governor_name, | |
575 | void *data) | |
576 | { | |
577 | struct devfreq **ptr, *devfreq; | |
578 | ||
579 | ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL); | |
580 | if (!ptr) | |
581 | return ERR_PTR(-ENOMEM); | |
582 | ||
583 | devfreq = devfreq_add_device(dev, profile, governor_name, data); | |
584 | if (IS_ERR(devfreq)) { | |
585 | devres_free(ptr); | |
586 | return ERR_PTR(-ENOMEM); | |
587 | } | |
588 | ||
589 | *ptr = devfreq; | |
590 | devres_add(dev, ptr); | |
591 | ||
592 | return devfreq; | |
593 | } | |
594 | EXPORT_SYMBOL(devm_devfreq_add_device); | |
595 | ||
596 | /** | |
597 | * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device() | |
598 | * @dev: the device to add devfreq feature. | |
599 | * @devfreq: the devfreq instance to be removed | |
600 | */ | |
601 | void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq) | |
602 | { | |
603 | WARN_ON(devres_release(dev, devm_devfreq_dev_release, | |
604 | devm_devfreq_dev_match, devfreq)); | |
605 | } | |
606 | EXPORT_SYMBOL(devm_devfreq_remove_device); | |
607 | ||
206c30cf RV |
608 | /** |
609 | * devfreq_suspend_device() - Suspend devfreq of a device. | |
610 | * @devfreq: the devfreq instance to be suspended | |
de9c7394 MH |
611 | * |
612 | * This function is intended to be called by the pm callbacks | |
613 | * (e.g., runtime_suspend, suspend) of the device driver that | |
614 | * holds the devfreq. | |
206c30cf RV |
615 | */ |
616 | int devfreq_suspend_device(struct devfreq *devfreq) | |
617 | { | |
a3c98b8b MH |
618 | if (!devfreq) |
619 | return -EINVAL; | |
620 | ||
1b5c1be2 NM |
621 | if (!devfreq->governor) |
622 | return 0; | |
623 | ||
206c30cf RV |
624 | return devfreq->governor->event_handler(devfreq, |
625 | DEVFREQ_GOV_SUSPEND, NULL); | |
626 | } | |
627 | EXPORT_SYMBOL(devfreq_suspend_device); | |
628 | ||
629 | /** | |
630 | * devfreq_resume_device() - Resume devfreq of a device. | |
631 | * @devfreq: the devfreq instance to be resumed | |
de9c7394 MH |
632 | * |
633 | * This function is intended to be called by the pm callbacks | |
634 | * (e.g., runtime_resume, resume) of the device driver that | |
635 | * holds the devfreq. | |
206c30cf RV |
636 | */ |
637 | int devfreq_resume_device(struct devfreq *devfreq) | |
638 | { | |
639 | if (!devfreq) | |
640 | return -EINVAL; | |
641 | ||
1b5c1be2 NM |
642 | if (!devfreq->governor) |
643 | return 0; | |
644 | ||
206c30cf RV |
645 | return devfreq->governor->event_handler(devfreq, |
646 | DEVFREQ_GOV_RESUME, NULL); | |
647 | } | |
648 | EXPORT_SYMBOL(devfreq_resume_device); | |
649 | ||
3aa173b8 NM |
650 | /** |
651 | * devfreq_add_governor() - Add devfreq governor | |
652 | * @governor: the devfreq governor to be added | |
653 | */ | |
654 | int devfreq_add_governor(struct devfreq_governor *governor) | |
655 | { | |
656 | struct devfreq_governor *g; | |
1b5c1be2 | 657 | struct devfreq *devfreq; |
3aa173b8 NM |
658 | int err = 0; |
659 | ||
660 | if (!governor) { | |
661 | pr_err("%s: Invalid parameters.\n", __func__); | |
662 | return -EINVAL; | |
663 | } | |
664 | ||
665 | mutex_lock(&devfreq_list_lock); | |
666 | g = find_devfreq_governor(governor->name); | |
667 | if (!IS_ERR(g)) { | |
668 | pr_err("%s: governor %s already registered\n", __func__, | |
669 | g->name); | |
670 | err = -EINVAL; | |
671 | goto err_out; | |
672 | } | |
9f3bdd4f | 673 | |
3aa173b8 NM |
674 | list_add(&governor->node, &devfreq_governor_list); |
675 | ||
1b5c1be2 NM |
676 | list_for_each_entry(devfreq, &devfreq_list, node) { |
677 | int ret = 0; | |
678 | struct device *dev = devfreq->dev.parent; | |
679 | ||
680 | if (!strncmp(devfreq->governor_name, governor->name, | |
681 | DEVFREQ_NAME_LEN)) { | |
682 | /* The following should never occur */ | |
683 | if (devfreq->governor) { | |
684 | dev_warn(dev, | |
685 | "%s: Governor %s already present\n", | |
686 | __func__, devfreq->governor->name); | |
687 | ret = devfreq->governor->event_handler(devfreq, | |
688 | DEVFREQ_GOV_STOP, NULL); | |
689 | if (ret) { | |
690 | dev_warn(dev, | |
691 | "%s: Governor %s stop = %d\n", | |
692 | __func__, | |
693 | devfreq->governor->name, ret); | |
694 | } | |
695 | /* Fall through */ | |
696 | } | |
697 | devfreq->governor = governor; | |
698 | ret = devfreq->governor->event_handler(devfreq, | |
699 | DEVFREQ_GOV_START, NULL); | |
700 | if (ret) { | |
701 | dev_warn(dev, "%s: Governor %s start=%d\n", | |
702 | __func__, devfreq->governor->name, | |
703 | ret); | |
704 | } | |
a3c98b8b MH |
705 | } |
706 | } | |
707 | ||
3aa173b8 NM |
708 | err_out: |
709 | mutex_unlock(&devfreq_list_lock); | |
a3c98b8b | 710 | |
3aa173b8 NM |
711 | return err; |
712 | } | |
713 | EXPORT_SYMBOL(devfreq_add_governor); | |
a3c98b8b | 714 | |
3aa173b8 NM |
715 | /** |
716 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
717 | * @governor: the devfreq governor to be removed | |
718 | */ | |
719 | int devfreq_remove_governor(struct devfreq_governor *governor) | |
720 | { | |
721 | struct devfreq_governor *g; | |
1b5c1be2 | 722 | struct devfreq *devfreq; |
3aa173b8 NM |
723 | int err = 0; |
724 | ||
725 | if (!governor) { | |
726 | pr_err("%s: Invalid parameters.\n", __func__); | |
727 | return -EINVAL; | |
728 | } | |
729 | ||
730 | mutex_lock(&devfreq_list_lock); | |
731 | g = find_devfreq_governor(governor->name); | |
732 | if (IS_ERR(g)) { | |
733 | pr_err("%s: governor %s not registered\n", __func__, | |
b9e1c8e8 | 734 | governor->name); |
f9c08e2a | 735 | err = PTR_ERR(g); |
3aa173b8 NM |
736 | goto err_out; |
737 | } | |
1b5c1be2 NM |
738 | list_for_each_entry(devfreq, &devfreq_list, node) { |
739 | int ret; | |
740 | struct device *dev = devfreq->dev.parent; | |
741 | ||
742 | if (!strncmp(devfreq->governor_name, governor->name, | |
743 | DEVFREQ_NAME_LEN)) { | |
744 | /* we should have a devfreq governor! */ | |
745 | if (!devfreq->governor) { | |
746 | dev_warn(dev, "%s: Governor %s NOT present\n", | |
747 | __func__, governor->name); | |
748 | continue; | |
749 | /* Fall through */ | |
750 | } | |
751 | ret = devfreq->governor->event_handler(devfreq, | |
752 | DEVFREQ_GOV_STOP, NULL); | |
753 | if (ret) { | |
754 | dev_warn(dev, "%s: Governor %s stop=%d\n", | |
755 | __func__, devfreq->governor->name, | |
756 | ret); | |
757 | } | |
758 | devfreq->governor = NULL; | |
759 | } | |
760 | } | |
3aa173b8 NM |
761 | |
762 | list_del(&governor->node); | |
763 | err_out: | |
764 | mutex_unlock(&devfreq_list_lock); | |
765 | ||
766 | return err; | |
a3c98b8b | 767 | } |
3aa173b8 | 768 | EXPORT_SYMBOL(devfreq_remove_governor); |
a3c98b8b | 769 | |
a93d6b0a | 770 | static ssize_t governor_show(struct device *dev, |
9005b650 MH |
771 | struct device_attribute *attr, char *buf) |
772 | { | |
1b5c1be2 NM |
773 | if (!to_devfreq(dev)->governor) |
774 | return -EINVAL; | |
775 | ||
9005b650 MH |
776 | return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); |
777 | } | |
778 | ||
a93d6b0a | 779 | static ssize_t governor_store(struct device *dev, struct device_attribute *attr, |
0359d1af NM |
780 | const char *buf, size_t count) |
781 | { | |
782 | struct devfreq *df = to_devfreq(dev); | |
783 | int ret; | |
784 | char str_governor[DEVFREQ_NAME_LEN + 1]; | |
785 | struct devfreq_governor *governor; | |
786 | ||
787 | ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); | |
788 | if (ret != 1) | |
789 | return -EINVAL; | |
790 | ||
791 | mutex_lock(&devfreq_list_lock); | |
792 | governor = find_devfreq_governor(str_governor); | |
793 | if (IS_ERR(governor)) { | |
794 | ret = PTR_ERR(governor); | |
795 | goto out; | |
796 | } | |
14a21e7b TJ |
797 | if (df->governor == governor) { |
798 | ret = 0; | |
0359d1af | 799 | goto out; |
14a21e7b | 800 | } |
0359d1af NM |
801 | |
802 | if (df->governor) { | |
803 | ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); | |
804 | if (ret) { | |
805 | dev_warn(dev, "%s: Governor %s not stopped(%d)\n", | |
806 | __func__, df->governor->name, ret); | |
807 | goto out; | |
808 | } | |
809 | } | |
810 | df->governor = governor; | |
811 | strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); | |
812 | ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); | |
813 | if (ret) | |
814 | dev_warn(dev, "%s: Governor %s not started(%d)\n", | |
815 | __func__, df->governor->name, ret); | |
816 | out: | |
817 | mutex_unlock(&devfreq_list_lock); | |
818 | ||
819 | if (!ret) | |
820 | ret = count; | |
821 | return ret; | |
822 | } | |
a93d6b0a GKH |
823 | static DEVICE_ATTR_RW(governor); |
824 | ||
825 | static ssize_t available_governors_show(struct device *d, | |
826 | struct device_attribute *attr, | |
827 | char *buf) | |
50a5b33e NM |
828 | { |
829 | struct devfreq_governor *tmp_governor; | |
830 | ssize_t count = 0; | |
831 | ||
832 | mutex_lock(&devfreq_list_lock); | |
833 | list_for_each_entry(tmp_governor, &devfreq_governor_list, node) | |
834 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
835 | "%s ", tmp_governor->name); | |
836 | mutex_unlock(&devfreq_list_lock); | |
837 | ||
838 | /* Truncate the trailing space */ | |
839 | if (count) | |
840 | count--; | |
841 | ||
842 | count += sprintf(&buf[count], "\n"); | |
843 | ||
844 | return count; | |
845 | } | |
a93d6b0a | 846 | static DEVICE_ATTR_RO(available_governors); |
0359d1af | 847 | |
a93d6b0a GKH |
848 | static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, |
849 | char *buf) | |
7f98a905 RV |
850 | { |
851 | unsigned long freq; | |
852 | struct devfreq *devfreq = to_devfreq(dev); | |
853 | ||
854 | if (devfreq->profile->get_cur_freq && | |
855 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
856 | return sprintf(buf, "%lu\n", freq); | |
857 | ||
858 | return sprintf(buf, "%lu\n", devfreq->previous_freq); | |
859 | } | |
a93d6b0a | 860 | static DEVICE_ATTR_RO(cur_freq); |
7f98a905 | 861 | |
a93d6b0a GKH |
862 | static ssize_t target_freq_show(struct device *dev, |
863 | struct device_attribute *attr, char *buf) | |
9005b650 MH |
864 | { |
865 | return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); | |
866 | } | |
a93d6b0a | 867 | static DEVICE_ATTR_RO(target_freq); |
9005b650 | 868 | |
a93d6b0a | 869 | static ssize_t polling_interval_show(struct device *dev, |
9005b650 MH |
870 | struct device_attribute *attr, char *buf) |
871 | { | |
872 | return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); | |
873 | } | |
874 | ||
a93d6b0a | 875 | static ssize_t polling_interval_store(struct device *dev, |
9005b650 MH |
876 | struct device_attribute *attr, |
877 | const char *buf, size_t count) | |
878 | { | |
879 | struct devfreq *df = to_devfreq(dev); | |
880 | unsigned int value; | |
881 | int ret; | |
882 | ||
1b5c1be2 NM |
883 | if (!df->governor) |
884 | return -EINVAL; | |
885 | ||
9005b650 MH |
886 | ret = sscanf(buf, "%u", &value); |
887 | if (ret != 1) | |
12e26265 | 888 | return -EINVAL; |
9005b650 | 889 | |
7e6fdd4b | 890 | df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); |
9005b650 MH |
891 | ret = count; |
892 | ||
9005b650 MH |
893 | return ret; |
894 | } | |
a93d6b0a | 895 | static DEVICE_ATTR_RW(polling_interval); |
9005b650 | 896 | |
a93d6b0a | 897 | static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
898 | const char *buf, size_t count) |
899 | { | |
900 | struct devfreq *df = to_devfreq(dev); | |
901 | unsigned long value; | |
902 | int ret; | |
903 | unsigned long max; | |
904 | ||
905 | ret = sscanf(buf, "%lu", &value); | |
906 | if (ret != 1) | |
12e26265 | 907 | return -EINVAL; |
6530b9de MH |
908 | |
909 | mutex_lock(&df->lock); | |
910 | max = df->max_freq; | |
911 | if (value && max && value > max) { | |
912 | ret = -EINVAL; | |
913 | goto unlock; | |
914 | } | |
915 | ||
916 | df->min_freq = value; | |
917 | update_devfreq(df); | |
918 | ret = count; | |
919 | unlock: | |
920 | mutex_unlock(&df->lock); | |
6530b9de MH |
921 | return ret; |
922 | } | |
923 | ||
a93d6b0a | 924 | static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
925 | char *buf) |
926 | { | |
927 | return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); | |
928 | } | |
929 | ||
a93d6b0a | 930 | static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
931 | const char *buf, size_t count) |
932 | { | |
933 | struct devfreq *df = to_devfreq(dev); | |
934 | unsigned long value; | |
935 | int ret; | |
936 | unsigned long min; | |
937 | ||
938 | ret = sscanf(buf, "%lu", &value); | |
939 | if (ret != 1) | |
12e26265 | 940 | return -EINVAL; |
6530b9de MH |
941 | |
942 | mutex_lock(&df->lock); | |
943 | min = df->min_freq; | |
944 | if (value && min && value < min) { | |
945 | ret = -EINVAL; | |
946 | goto unlock; | |
947 | } | |
948 | ||
949 | df->max_freq = value; | |
950 | update_devfreq(df); | |
951 | ret = count; | |
952 | unlock: | |
953 | mutex_unlock(&df->lock); | |
6530b9de MH |
954 | return ret; |
955 | } | |
a93d6b0a | 956 | static DEVICE_ATTR_RW(min_freq); |
6530b9de | 957 | |
a93d6b0a | 958 | static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, |
6530b9de MH |
959 | char *buf) |
960 | { | |
961 | return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); | |
962 | } | |
a93d6b0a | 963 | static DEVICE_ATTR_RW(max_freq); |
6530b9de | 964 | |
a93d6b0a GKH |
965 | static ssize_t available_frequencies_show(struct device *d, |
966 | struct device_attribute *attr, | |
967 | char *buf) | |
d287de85 NM |
968 | { |
969 | struct devfreq *df = to_devfreq(d); | |
970 | struct device *dev = df->dev.parent; | |
47d43ba7 | 971 | struct dev_pm_opp *opp; |
d287de85 NM |
972 | ssize_t count = 0; |
973 | unsigned long freq = 0; | |
974 | ||
975 | rcu_read_lock(); | |
976 | do { | |
5d4879cd | 977 | opp = dev_pm_opp_find_freq_ceil(dev, &freq); |
d287de85 NM |
978 | if (IS_ERR(opp)) |
979 | break; | |
980 | ||
981 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
982 | "%lu ", freq); | |
983 | freq++; | |
984 | } while (1); | |
985 | rcu_read_unlock(); | |
986 | ||
987 | /* Truncate the trailing space */ | |
988 | if (count) | |
989 | count--; | |
990 | ||
991 | count += sprintf(&buf[count], "\n"); | |
992 | ||
993 | return count; | |
994 | } | |
a93d6b0a | 995 | static DEVICE_ATTR_RO(available_frequencies); |
d287de85 | 996 | |
a93d6b0a GKH |
997 | static ssize_t trans_stat_show(struct device *dev, |
998 | struct device_attribute *attr, char *buf) | |
e552bbaf JL |
999 | { |
1000 | struct devfreq *devfreq = to_devfreq(dev); | |
1001 | ssize_t len; | |
39688ce6 | 1002 | int i, j; |
e552bbaf JL |
1003 | unsigned int max_state = devfreq->profile->max_state; |
1004 | ||
39688ce6 RV |
1005 | if (!devfreq->stop_polling && |
1006 | devfreq_update_status(devfreq, devfreq->previous_freq)) | |
e552bbaf JL |
1007 | return 0; |
1008 | ||
1009 | len = sprintf(buf, " From : To\n"); | |
1010 | len += sprintf(buf + len, " :"); | |
1011 | for (i = 0; i < max_state; i++) | |
1012 | len += sprintf(buf + len, "%8u", | |
1013 | devfreq->profile->freq_table[i]); | |
1014 | ||
1015 | len += sprintf(buf + len, " time(ms)\n"); | |
1016 | ||
1017 | for (i = 0; i < max_state; i++) { | |
1018 | if (devfreq->profile->freq_table[i] | |
1019 | == devfreq->previous_freq) { | |
1020 | len += sprintf(buf + len, "*"); | |
1021 | } else { | |
1022 | len += sprintf(buf + len, " "); | |
1023 | } | |
1024 | len += sprintf(buf + len, "%8u:", | |
1025 | devfreq->profile->freq_table[i]); | |
1026 | for (j = 0; j < max_state; j++) | |
1027 | len += sprintf(buf + len, "%8u", | |
1028 | devfreq->trans_table[(i * max_state) + j]); | |
1029 | len += sprintf(buf + len, "%10u\n", | |
1030 | jiffies_to_msecs(devfreq->time_in_state[i])); | |
1031 | } | |
1032 | ||
1033 | len += sprintf(buf + len, "Total transition : %u\n", | |
1034 | devfreq->total_trans); | |
1035 | return len; | |
1036 | } | |
a93d6b0a GKH |
1037 | static DEVICE_ATTR_RO(trans_stat); |
1038 | ||
1039 | static struct attribute *devfreq_attrs[] = { | |
1040 | &dev_attr_governor.attr, | |
1041 | &dev_attr_available_governors.attr, | |
1042 | &dev_attr_cur_freq.attr, | |
1043 | &dev_attr_available_frequencies.attr, | |
1044 | &dev_attr_target_freq.attr, | |
1045 | &dev_attr_polling_interval.attr, | |
1046 | &dev_attr_min_freq.attr, | |
1047 | &dev_attr_max_freq.attr, | |
1048 | &dev_attr_trans_stat.attr, | |
1049 | NULL, | |
9005b650 | 1050 | }; |
a93d6b0a | 1051 | ATTRIBUTE_GROUPS(devfreq); |
9005b650 | 1052 | |
a3c98b8b MH |
1053 | static int __init devfreq_init(void) |
1054 | { | |
1055 | devfreq_class = class_create(THIS_MODULE, "devfreq"); | |
1056 | if (IS_ERR(devfreq_class)) { | |
1057 | pr_err("%s: couldn't create class\n", __FILE__); | |
1058 | return PTR_ERR(devfreq_class); | |
1059 | } | |
7e6fdd4b RV |
1060 | |
1061 | devfreq_wq = create_freezable_workqueue("devfreq_wq"); | |
ea7f4548 | 1062 | if (!devfreq_wq) { |
7e6fdd4b RV |
1063 | class_destroy(devfreq_class); |
1064 | pr_err("%s: couldn't create workqueue\n", __FILE__); | |
ea7f4548 | 1065 | return -ENOMEM; |
7e6fdd4b | 1066 | } |
a93d6b0a | 1067 | devfreq_class->dev_groups = devfreq_groups; |
7e6fdd4b | 1068 | |
a3c98b8b MH |
1069 | return 0; |
1070 | } | |
1071 | subsys_initcall(devfreq_init); | |
1072 | ||
1073 | static void __exit devfreq_exit(void) | |
1074 | { | |
1075 | class_destroy(devfreq_class); | |
7e6fdd4b | 1076 | destroy_workqueue(devfreq_wq); |
a3c98b8b MH |
1077 | } |
1078 | module_exit(devfreq_exit); | |
1079 | ||
1080 | /* | |
1081 | * The followings are helper functions for devfreq user device drivers with | |
1082 | * OPP framework. | |
1083 | */ | |
1084 | ||
1085 | /** | |
1086 | * devfreq_recommended_opp() - Helper function to get proper OPP for the | |
1087 | * freq value given to target callback. | |
c5b4a1c1 NM |
1088 | * @dev: The devfreq user device. (parent of devfreq) |
1089 | * @freq: The frequency given to target function | |
1090 | * @flags: Flags handed from devfreq framework. | |
a3c98b8b | 1091 | * |
bcb27549 NM |
1092 | * Locking: This function must be called under rcu_read_lock(). opp is a rcu |
1093 | * protected pointer. The reason for the same is that the opp pointer which is | |
1094 | * returned will remain valid for use with opp_get_{voltage, freq} only while | |
1095 | * under the locked area. The pointer returned must be used prior to unlocking | |
1096 | * with rcu_read_unlock() to maintain the integrity of the pointer. | |
a3c98b8b | 1097 | */ |
47d43ba7 NM |
1098 | struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, |
1099 | unsigned long *freq, | |
1100 | u32 flags) | |
a3c98b8b | 1101 | { |
47d43ba7 | 1102 | struct dev_pm_opp *opp; |
a3c98b8b | 1103 | |
ab5f299f MH |
1104 | if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { |
1105 | /* The freq is an upper bound. opp should be lower */ | |
5d4879cd | 1106 | opp = dev_pm_opp_find_freq_floor(dev, freq); |
ab5f299f MH |
1107 | |
1108 | /* If not available, use the closest opp */ | |
0779726c | 1109 | if (opp == ERR_PTR(-ERANGE)) |
5d4879cd | 1110 | opp = dev_pm_opp_find_freq_ceil(dev, freq); |
ab5f299f MH |
1111 | } else { |
1112 | /* The freq is an lower bound. opp should be higher */ | |
5d4879cd | 1113 | opp = dev_pm_opp_find_freq_ceil(dev, freq); |
ab5f299f MH |
1114 | |
1115 | /* If not available, use the closest opp */ | |
0779726c | 1116 | if (opp == ERR_PTR(-ERANGE)) |
5d4879cd | 1117 | opp = dev_pm_opp_find_freq_floor(dev, freq); |
ab5f299f MH |
1118 | } |
1119 | ||
a3c98b8b MH |
1120 | return opp; |
1121 | } | |
bd7e9277 | 1122 | EXPORT_SYMBOL(devfreq_recommended_opp); |
a3c98b8b MH |
1123 | |
1124 | /** | |
1125 | * devfreq_register_opp_notifier() - Helper function to get devfreq notified | |
1126 | * for any changes in the OPP availability | |
1127 | * changes | |
c5b4a1c1 NM |
1128 | * @dev: The devfreq user device. (parent of devfreq) |
1129 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
1130 | */ |
1131 | int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1132 | { | |
389baed0 MH |
1133 | struct srcu_notifier_head *nh; |
1134 | int ret = 0; | |
a3c98b8b | 1135 | |
389baed0 | 1136 | rcu_read_lock(); |
5d4879cd | 1137 | nh = dev_pm_opp_get_notifier(dev); |
a3c98b8b | 1138 | if (IS_ERR(nh)) |
389baed0 MH |
1139 | ret = PTR_ERR(nh); |
1140 | rcu_read_unlock(); | |
1141 | if (!ret) | |
1142 | ret = srcu_notifier_chain_register(nh, &devfreq->nb); | |
1143 | ||
1144 | return ret; | |
a3c98b8b | 1145 | } |
bd7e9277 | 1146 | EXPORT_SYMBOL(devfreq_register_opp_notifier); |
a3c98b8b MH |
1147 | |
1148 | /** | |
1149 | * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq | |
1150 | * notified for any changes in the OPP | |
1151 | * availability changes anymore. | |
c5b4a1c1 NM |
1152 | * @dev: The devfreq user device. (parent of devfreq) |
1153 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
1154 | * |
1155 | * At exit() callback of devfreq_dev_profile, this must be included if | |
1156 | * devfreq_recommended_opp is used. | |
1157 | */ | |
1158 | int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
1159 | { | |
389baed0 MH |
1160 | struct srcu_notifier_head *nh; |
1161 | int ret = 0; | |
a3c98b8b | 1162 | |
389baed0 | 1163 | rcu_read_lock(); |
5d4879cd | 1164 | nh = dev_pm_opp_get_notifier(dev); |
a3c98b8b | 1165 | if (IS_ERR(nh)) |
389baed0 MH |
1166 | ret = PTR_ERR(nh); |
1167 | rcu_read_unlock(); | |
1168 | if (!ret) | |
1169 | ret = srcu_notifier_chain_unregister(nh, &devfreq->nb); | |
1170 | ||
1171 | return ret; | |
a3c98b8b | 1172 | } |
bd7e9277 | 1173 | EXPORT_SYMBOL(devfreq_unregister_opp_notifier); |
a3c98b8b | 1174 | |
d5b040d0 CC |
1175 | static void devm_devfreq_opp_release(struct device *dev, void *res) |
1176 | { | |
1177 | devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res); | |
1178 | } | |
1179 | ||
1180 | /** | |
1181 | * devm_ devfreq_register_opp_notifier() | |
1182 | * - Resource-managed devfreq_register_opp_notifier() | |
1183 | * @dev: The devfreq user device. (parent of devfreq) | |
1184 | * @devfreq: The devfreq object. | |
1185 | */ | |
1186 | int devm_devfreq_register_opp_notifier(struct device *dev, | |
1187 | struct devfreq *devfreq) | |
1188 | { | |
1189 | struct devfreq **ptr; | |
1190 | int ret; | |
1191 | ||
1192 | ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL); | |
1193 | if (!ptr) | |
1194 | return -ENOMEM; | |
1195 | ||
1196 | ret = devfreq_register_opp_notifier(dev, devfreq); | |
1197 | if (ret) { | |
1198 | devres_free(ptr); | |
1199 | return ret; | |
1200 | } | |
1201 | ||
1202 | *ptr = devfreq; | |
1203 | devres_add(dev, ptr); | |
1204 | ||
1205 | return 0; | |
1206 | } | |
1207 | EXPORT_SYMBOL(devm_devfreq_register_opp_notifier); | |
1208 | ||
1209 | /** | |
1210 | * devm_devfreq_unregister_opp_notifier() | |
1211 | * - Resource-managed devfreq_unregister_opp_notifier() | |
1212 | * @dev: The devfreq user device. (parent of devfreq) | |
1213 | * @devfreq: The devfreq object. | |
1214 | */ | |
1215 | void devm_devfreq_unregister_opp_notifier(struct device *dev, | |
1216 | struct devfreq *devfreq) | |
1217 | { | |
1218 | WARN_ON(devres_release(dev, devm_devfreq_opp_release, | |
1219 | devm_devfreq_dev_match, devfreq)); | |
1220 | } | |
1221 | EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier); | |
1222 | ||
a3c98b8b MH |
1223 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); |
1224 | MODULE_DESCRIPTION("devfreq class support"); | |
1225 | MODULE_LICENSE("GPL"); |