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> |
a3c98b8b MH |
21 | #include <linux/opp.h> |
22 | #include <linux/devfreq.h> | |
23 | #include <linux/workqueue.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/list.h> | |
26 | #include <linux/printk.h> | |
27 | #include <linux/hrtimer.h> | |
28 | #include "governor.h" | |
29 | ||
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 | { | |
94 | int lev, prev_lev; | |
95 | unsigned long cur_time; | |
96 | ||
97 | lev = devfreq_get_freq_level(devfreq, freq); | |
98 | if (lev < 0) | |
99 | return lev; | |
100 | ||
101 | cur_time = jiffies; | |
102 | devfreq->time_in_state[lev] += | |
103 | cur_time - devfreq->last_stat_updated; | |
104 | if (freq != devfreq->previous_freq) { | |
105 | prev_lev = devfreq_get_freq_level(devfreq, | |
106 | devfreq->previous_freq); | |
107 | devfreq->trans_table[(prev_lev * | |
108 | devfreq->profile->max_state) + lev]++; | |
109 | devfreq->total_trans++; | |
110 | } | |
111 | devfreq->last_stat_updated = cur_time; | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
3aa173b8 NM |
116 | /** |
117 | * find_devfreq_governor() - find devfreq governor from name | |
118 | * @name: name of the governor | |
119 | * | |
120 | * Search the list of devfreq governors and return the matched | |
121 | * governor's pointer. devfreq_list_lock should be held by the caller. | |
122 | */ | |
123 | static struct devfreq_governor *find_devfreq_governor(const char *name) | |
124 | { | |
125 | struct devfreq_governor *tmp_governor; | |
126 | ||
127 | if (unlikely(IS_ERR_OR_NULL(name))) { | |
128 | pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); | |
129 | return ERR_PTR(-EINVAL); | |
130 | } | |
131 | WARN(!mutex_is_locked(&devfreq_list_lock), | |
132 | "devfreq_list_lock must be locked."); | |
133 | ||
134 | list_for_each_entry(tmp_governor, &devfreq_governor_list, node) { | |
135 | if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN)) | |
136 | return tmp_governor; | |
137 | } | |
138 | ||
139 | return ERR_PTR(-ENODEV); | |
140 | } | |
141 | ||
7e6fdd4b RV |
142 | /* Load monitoring helper functions for governors use */ |
143 | ||
a3c98b8b MH |
144 | /** |
145 | * update_devfreq() - Reevaluate the device and configure frequency. | |
146 | * @devfreq: the devfreq instance. | |
147 | * | |
148 | * Note: Lock devfreq->lock before calling update_devfreq | |
149 | * This function is exported for governors. | |
150 | */ | |
151 | int update_devfreq(struct devfreq *devfreq) | |
152 | { | |
153 | unsigned long freq; | |
154 | int err = 0; | |
ab5f299f | 155 | u32 flags = 0; |
a3c98b8b MH |
156 | |
157 | if (!mutex_is_locked(&devfreq->lock)) { | |
158 | WARN(true, "devfreq->lock must be locked by the caller.\n"); | |
159 | return -EINVAL; | |
160 | } | |
161 | ||
162 | /* Reevaluate the proper frequency */ | |
163 | err = devfreq->governor->get_target_freq(devfreq, &freq); | |
164 | if (err) | |
165 | return err; | |
166 | ||
ab5f299f MH |
167 | /* |
168 | * Adjust the freuqency with user freq and QoS. | |
169 | * | |
170 | * List from the highest proiority | |
171 | * max_freq (probably called by thermal when it's too hot) | |
172 | * min_freq | |
173 | */ | |
174 | ||
175 | if (devfreq->min_freq && freq < devfreq->min_freq) { | |
176 | freq = devfreq->min_freq; | |
177 | flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ | |
178 | } | |
179 | if (devfreq->max_freq && freq > devfreq->max_freq) { | |
180 | freq = devfreq->max_freq; | |
181 | flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */ | |
182 | } | |
183 | ||
184 | err = devfreq->profile->target(devfreq->dev.parent, &freq, flags); | |
a3c98b8b MH |
185 | if (err) |
186 | return err; | |
187 | ||
e552bbaf JL |
188 | if (devfreq->profile->freq_table) |
189 | if (devfreq_update_status(devfreq, freq)) | |
190 | dev_err(&devfreq->dev, | |
191 | "Couldn't update frequency transition information.\n"); | |
192 | ||
a3c98b8b MH |
193 | devfreq->previous_freq = freq; |
194 | return err; | |
195 | } | |
2df5021f | 196 | EXPORT_SYMBOL(update_devfreq); |
a3c98b8b | 197 | |
7e6fdd4b RV |
198 | /** |
199 | * devfreq_monitor() - Periodically poll devfreq objects. | |
200 | * @work: the work struct used to run devfreq_monitor periodically. | |
201 | * | |
202 | */ | |
203 | static void devfreq_monitor(struct work_struct *work) | |
204 | { | |
205 | int err; | |
206 | struct devfreq *devfreq = container_of(work, | |
207 | struct devfreq, work.work); | |
208 | ||
209 | mutex_lock(&devfreq->lock); | |
210 | err = update_devfreq(devfreq); | |
211 | if (err) | |
212 | dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err); | |
213 | ||
214 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
215 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
216 | mutex_unlock(&devfreq->lock); | |
217 | } | |
218 | ||
219 | /** | |
220 | * devfreq_monitor_start() - Start load monitoring of devfreq instance | |
221 | * @devfreq: the devfreq instance. | |
222 | * | |
223 | * Helper function for starting devfreq device load monitoing. By | |
224 | * default delayed work based monitoring is supported. Function | |
225 | * to be called from governor in response to DEVFREQ_GOV_START | |
226 | * event when device is added to devfreq framework. | |
227 | */ | |
228 | void devfreq_monitor_start(struct devfreq *devfreq) | |
229 | { | |
230 | INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); | |
231 | if (devfreq->profile->polling_ms) | |
232 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
233 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
234 | } | |
235 | ||
236 | /** | |
237 | * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance | |
238 | * @devfreq: the devfreq instance. | |
239 | * | |
240 | * Helper function to stop devfreq device load monitoing. Function | |
241 | * to be called from governor in response to DEVFREQ_GOV_STOP | |
242 | * event when device is removed from devfreq framework. | |
243 | */ | |
244 | void devfreq_monitor_stop(struct devfreq *devfreq) | |
245 | { | |
246 | cancel_delayed_work_sync(&devfreq->work); | |
247 | } | |
248 | ||
249 | /** | |
250 | * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance | |
251 | * @devfreq: the devfreq instance. | |
252 | * | |
253 | * Helper function to suspend devfreq device load monitoing. Function | |
254 | * to be called from governor in response to DEVFREQ_GOV_SUSPEND | |
255 | * event or when polling interval is set to zero. | |
256 | * | |
257 | * Note: Though this function is same as devfreq_monitor_stop(), | |
258 | * intentionally kept separate to provide hooks for collecting | |
259 | * transition statistics. | |
260 | */ | |
261 | void devfreq_monitor_suspend(struct devfreq *devfreq) | |
262 | { | |
263 | mutex_lock(&devfreq->lock); | |
264 | if (devfreq->stop_polling) { | |
265 | mutex_unlock(&devfreq->lock); | |
266 | return; | |
267 | } | |
268 | ||
269 | devfreq->stop_polling = true; | |
270 | mutex_unlock(&devfreq->lock); | |
271 | cancel_delayed_work_sync(&devfreq->work); | |
272 | } | |
273 | ||
274 | /** | |
275 | * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance | |
276 | * @devfreq: the devfreq instance. | |
277 | * | |
278 | * Helper function to resume devfreq device load monitoing. Function | |
279 | * to be called from governor in response to DEVFREQ_GOV_RESUME | |
280 | * event or when polling interval is set to non-zero. | |
281 | */ | |
282 | void devfreq_monitor_resume(struct devfreq *devfreq) | |
283 | { | |
284 | mutex_lock(&devfreq->lock); | |
285 | if (!devfreq->stop_polling) | |
286 | goto out; | |
287 | ||
288 | if (!delayed_work_pending(&devfreq->work) && | |
289 | devfreq->profile->polling_ms) | |
290 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
291 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
292 | devfreq->stop_polling = false; | |
293 | ||
294 | out: | |
295 | mutex_unlock(&devfreq->lock); | |
296 | } | |
297 | ||
298 | /** | |
299 | * devfreq_interval_update() - Update device devfreq monitoring interval | |
300 | * @devfreq: the devfreq instance. | |
301 | * @delay: new polling interval to be set. | |
302 | * | |
303 | * Helper function to set new load monitoring polling interval. Function | |
304 | * to be called from governor in response to DEVFREQ_GOV_INTERVAL event. | |
305 | */ | |
306 | void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay) | |
307 | { | |
308 | unsigned int cur_delay = devfreq->profile->polling_ms; | |
309 | unsigned int new_delay = *delay; | |
310 | ||
311 | mutex_lock(&devfreq->lock); | |
312 | devfreq->profile->polling_ms = new_delay; | |
313 | ||
314 | if (devfreq->stop_polling) | |
315 | goto out; | |
316 | ||
317 | /* if new delay is zero, stop polling */ | |
318 | if (!new_delay) { | |
319 | mutex_unlock(&devfreq->lock); | |
320 | cancel_delayed_work_sync(&devfreq->work); | |
321 | return; | |
322 | } | |
323 | ||
324 | /* if current delay is zero, start polling with new delay */ | |
325 | if (!cur_delay) { | |
326 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
327 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
328 | goto out; | |
329 | } | |
330 | ||
331 | /* if current delay is greater than new delay, restart polling */ | |
332 | if (cur_delay > new_delay) { | |
333 | mutex_unlock(&devfreq->lock); | |
334 | cancel_delayed_work_sync(&devfreq->work); | |
335 | mutex_lock(&devfreq->lock); | |
336 | if (!devfreq->stop_polling) | |
337 | queue_delayed_work(devfreq_wq, &devfreq->work, | |
338 | msecs_to_jiffies(devfreq->profile->polling_ms)); | |
339 | } | |
340 | out: | |
341 | mutex_unlock(&devfreq->lock); | |
342 | } | |
343 | ||
a3c98b8b MH |
344 | /** |
345 | * devfreq_notifier_call() - Notify that the device frequency requirements | |
346 | * has been changed out of devfreq framework. | |
c5b4a1c1 NM |
347 | * @nb: the notifier_block (supposed to be devfreq->nb) |
348 | * @type: not used | |
349 | * @devp: not used | |
a3c98b8b MH |
350 | * |
351 | * Called by a notifier that uses devfreq->nb. | |
352 | */ | |
353 | static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, | |
354 | void *devp) | |
355 | { | |
356 | struct devfreq *devfreq = container_of(nb, struct devfreq, nb); | |
357 | int ret; | |
358 | ||
359 | mutex_lock(&devfreq->lock); | |
360 | ret = update_devfreq(devfreq); | |
361 | mutex_unlock(&devfreq->lock); | |
362 | ||
363 | return ret; | |
364 | } | |
365 | ||
366 | /** | |
7e6fdd4b | 367 | * _remove_devfreq() - Remove devfreq from the list and release its resources. |
a3c98b8b MH |
368 | * @devfreq: the devfreq struct |
369 | * @skip: skip calling device_unregister(). | |
a3c98b8b MH |
370 | */ |
371 | static void _remove_devfreq(struct devfreq *devfreq, bool skip) | |
372 | { | |
7e6fdd4b RV |
373 | mutex_lock(&devfreq_list_lock); |
374 | if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { | |
375 | mutex_unlock(&devfreq_list_lock); | |
376 | dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); | |
a3c98b8b MH |
377 | return; |
378 | } | |
7e6fdd4b RV |
379 | list_del(&devfreq->node); |
380 | mutex_unlock(&devfreq_list_lock); | |
a3c98b8b | 381 | |
7e6fdd4b | 382 | devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_STOP, NULL); |
a3c98b8b MH |
383 | |
384 | if (devfreq->profile->exit) | |
385 | devfreq->profile->exit(devfreq->dev.parent); | |
386 | ||
a3c98b8b MH |
387 | if (!skip && get_device(&devfreq->dev)) { |
388 | device_unregister(&devfreq->dev); | |
389 | put_device(&devfreq->dev); | |
390 | } | |
391 | ||
a3c98b8b | 392 | mutex_destroy(&devfreq->lock); |
a3c98b8b MH |
393 | kfree(devfreq); |
394 | } | |
395 | ||
396 | /** | |
397 | * devfreq_dev_release() - Callback for struct device to release the device. | |
398 | * @dev: the devfreq device | |
399 | * | |
400 | * This calls _remove_devfreq() if _remove_devfreq() is not called. | |
401 | * Note that devfreq_dev_release() could be called by _remove_devfreq() as | |
402 | * well as by others unregistering the device. | |
403 | */ | |
404 | static void devfreq_dev_release(struct device *dev) | |
405 | { | |
406 | struct devfreq *devfreq = to_devfreq(dev); | |
a3c98b8b | 407 | |
a3c98b8b | 408 | _remove_devfreq(devfreq, true); |
a3c98b8b MH |
409 | } |
410 | ||
411 | /** | |
412 | * devfreq_add_device() - Add devfreq feature to the device | |
413 | * @dev: the device to add devfreq feature. | |
414 | * @profile: device-specific profile to run devfreq. | |
415 | * @governor: the policy to choose frequency. | |
416 | * @data: private data for the governor. The devfreq framework does not | |
417 | * touch this value. | |
418 | */ | |
419 | struct devfreq *devfreq_add_device(struct device *dev, | |
420 | struct devfreq_dev_profile *profile, | |
421 | const struct devfreq_governor *governor, | |
422 | void *data) | |
423 | { | |
424 | struct devfreq *devfreq; | |
425 | int err = 0; | |
426 | ||
427 | if (!dev || !profile || !governor) { | |
428 | dev_err(dev, "%s: Invalid parameters.\n", __func__); | |
429 | return ERR_PTR(-EINVAL); | |
430 | } | |
431 | ||
7e6fdd4b RV |
432 | mutex_lock(&devfreq_list_lock); |
433 | devfreq = find_device_devfreq(dev); | |
434 | mutex_unlock(&devfreq_list_lock); | |
435 | if (!IS_ERR(devfreq)) { | |
436 | dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__); | |
437 | err = -EINVAL; | |
438 | goto err_out; | |
a3c98b8b MH |
439 | } |
440 | ||
441 | devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); | |
442 | if (!devfreq) { | |
443 | dev_err(dev, "%s: Unable to create devfreq for the device\n", | |
444 | __func__); | |
445 | err = -ENOMEM; | |
3f19f08a | 446 | goto err_out; |
a3c98b8b MH |
447 | } |
448 | ||
449 | mutex_init(&devfreq->lock); | |
450 | mutex_lock(&devfreq->lock); | |
451 | devfreq->dev.parent = dev; | |
452 | devfreq->dev.class = devfreq_class; | |
453 | devfreq->dev.release = devfreq_dev_release; | |
454 | devfreq->profile = profile; | |
455 | devfreq->governor = governor; | |
456 | devfreq->previous_freq = profile->initial_freq; | |
457 | devfreq->data = data; | |
a3c98b8b MH |
458 | devfreq->nb.notifier_call = devfreq_notifier_call; |
459 | ||
e552bbaf JL |
460 | devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) * |
461 | devfreq->profile->max_state * | |
462 | devfreq->profile->max_state, | |
463 | GFP_KERNEL); | |
464 | devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned int) * | |
465 | devfreq->profile->max_state, | |
466 | GFP_KERNEL); | |
467 | devfreq->last_stat_updated = jiffies; | |
468 | ||
a3c98b8b MH |
469 | dev_set_name(&devfreq->dev, dev_name(dev)); |
470 | err = device_register(&devfreq->dev); | |
471 | if (err) { | |
472 | put_device(&devfreq->dev); | |
7e6fdd4b | 473 | mutex_unlock(&devfreq->lock); |
a3c98b8b MH |
474 | goto err_dev; |
475 | } | |
476 | ||
a3c98b8b MH |
477 | mutex_unlock(&devfreq->lock); |
478 | ||
a3c98b8b | 479 | mutex_lock(&devfreq_list_lock); |
a3c98b8b | 480 | list_add(&devfreq->node, &devfreq_list); |
7e6fdd4b | 481 | mutex_unlock(&devfreq_list_lock); |
a3c98b8b | 482 | |
7e6fdd4b RV |
483 | err = devfreq->governor->event_handler(devfreq, |
484 | DEVFREQ_GOV_START, NULL); | |
485 | if (err) { | |
486 | dev_err(dev, "%s: Unable to start governor for the device\n", | |
487 | __func__); | |
488 | goto err_init; | |
a3c98b8b | 489 | } |
7e6fdd4b | 490 | |
3f19f08a AL |
491 | return devfreq; |
492 | ||
a3c98b8b | 493 | err_init: |
7e6fdd4b | 494 | list_del(&devfreq->node); |
a3c98b8b MH |
495 | device_unregister(&devfreq->dev); |
496 | err_dev: | |
a3c98b8b | 497 | kfree(devfreq); |
3f19f08a AL |
498 | err_out: |
499 | return ERR_PTR(err); | |
a3c98b8b | 500 | } |
7e6fdd4b | 501 | EXPORT_SYMBOL(devfreq_add_device); |
a3c98b8b MH |
502 | |
503 | /** | |
504 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
c5b4a1c1 | 505 | * @devfreq: the devfreq instance to be removed |
a3c98b8b MH |
506 | */ |
507 | int devfreq_remove_device(struct devfreq *devfreq) | |
508 | { | |
509 | if (!devfreq) | |
510 | return -EINVAL; | |
511 | ||
7e6fdd4b | 512 | _remove_devfreq(devfreq, false); |
a3c98b8b MH |
513 | |
514 | return 0; | |
515 | } | |
7e6fdd4b | 516 | EXPORT_SYMBOL(devfreq_remove_device); |
a3c98b8b | 517 | |
206c30cf RV |
518 | /** |
519 | * devfreq_suspend_device() - Suspend devfreq of a device. | |
520 | * @devfreq: the devfreq instance to be suspended | |
521 | */ | |
522 | int devfreq_suspend_device(struct devfreq *devfreq) | |
523 | { | |
524 | if (!devfreq) | |
525 | return -EINVAL; | |
526 | ||
527 | return devfreq->governor->event_handler(devfreq, | |
528 | DEVFREQ_GOV_SUSPEND, NULL); | |
529 | } | |
530 | EXPORT_SYMBOL(devfreq_suspend_device); | |
531 | ||
532 | /** | |
533 | * devfreq_resume_device() - Resume devfreq of a device. | |
534 | * @devfreq: the devfreq instance to be resumed | |
535 | */ | |
536 | int devfreq_resume_device(struct devfreq *devfreq) | |
537 | { | |
538 | if (!devfreq) | |
539 | return -EINVAL; | |
540 | ||
541 | return devfreq->governor->event_handler(devfreq, | |
542 | DEVFREQ_GOV_RESUME, NULL); | |
543 | } | |
544 | EXPORT_SYMBOL(devfreq_resume_device); | |
545 | ||
3aa173b8 NM |
546 | /** |
547 | * devfreq_add_governor() - Add devfreq governor | |
548 | * @governor: the devfreq governor to be added | |
549 | */ | |
550 | int devfreq_add_governor(struct devfreq_governor *governor) | |
551 | { | |
552 | struct devfreq_governor *g; | |
553 | int err = 0; | |
554 | ||
555 | if (!governor) { | |
556 | pr_err("%s: Invalid parameters.\n", __func__); | |
557 | return -EINVAL; | |
558 | } | |
559 | ||
560 | mutex_lock(&devfreq_list_lock); | |
561 | g = find_devfreq_governor(governor->name); | |
562 | if (!IS_ERR(g)) { | |
563 | pr_err("%s: governor %s already registered\n", __func__, | |
564 | g->name); | |
565 | err = -EINVAL; | |
566 | goto err_out; | |
567 | } | |
568 | ||
569 | list_add(&governor->node, &devfreq_governor_list); | |
570 | ||
571 | err_out: | |
572 | mutex_unlock(&devfreq_list_lock); | |
573 | ||
574 | return err; | |
575 | } | |
576 | EXPORT_SYMBOL(devfreq_add_governor); | |
577 | ||
578 | /** | |
579 | * devfreq_remove_device() - Remove devfreq feature from a device. | |
580 | * @governor: the devfreq governor to be removed | |
581 | */ | |
582 | int devfreq_remove_governor(struct devfreq_governor *governor) | |
583 | { | |
584 | struct devfreq_governor *g; | |
585 | int err = 0; | |
586 | ||
587 | if (!governor) { | |
588 | pr_err("%s: Invalid parameters.\n", __func__); | |
589 | return -EINVAL; | |
590 | } | |
591 | ||
592 | mutex_lock(&devfreq_list_lock); | |
593 | g = find_devfreq_governor(governor->name); | |
594 | if (IS_ERR(g)) { | |
595 | pr_err("%s: governor %s not registered\n", __func__, | |
596 | g->name); | |
597 | err = -EINVAL; | |
598 | goto err_out; | |
599 | } | |
600 | ||
601 | list_del(&governor->node); | |
602 | err_out: | |
603 | mutex_unlock(&devfreq_list_lock); | |
604 | ||
605 | return err; | |
606 | } | |
607 | EXPORT_SYMBOL(devfreq_remove_governor); | |
608 | ||
9005b650 MH |
609 | static ssize_t show_governor(struct device *dev, |
610 | struct device_attribute *attr, char *buf) | |
611 | { | |
612 | return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name); | |
613 | } | |
614 | ||
615 | static ssize_t show_freq(struct device *dev, | |
616 | struct device_attribute *attr, char *buf) | |
7f98a905 RV |
617 | { |
618 | unsigned long freq; | |
619 | struct devfreq *devfreq = to_devfreq(dev); | |
620 | ||
621 | if (devfreq->profile->get_cur_freq && | |
622 | !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) | |
623 | return sprintf(buf, "%lu\n", freq); | |
624 | ||
625 | return sprintf(buf, "%lu\n", devfreq->previous_freq); | |
626 | } | |
627 | ||
628 | static ssize_t show_target_freq(struct device *dev, | |
629 | struct device_attribute *attr, char *buf) | |
9005b650 MH |
630 | { |
631 | return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq); | |
632 | } | |
633 | ||
634 | static ssize_t show_polling_interval(struct device *dev, | |
635 | struct device_attribute *attr, char *buf) | |
636 | { | |
637 | return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms); | |
638 | } | |
639 | ||
640 | static ssize_t store_polling_interval(struct device *dev, | |
641 | struct device_attribute *attr, | |
642 | const char *buf, size_t count) | |
643 | { | |
644 | struct devfreq *df = to_devfreq(dev); | |
645 | unsigned int value; | |
646 | int ret; | |
647 | ||
648 | ret = sscanf(buf, "%u", &value); | |
649 | if (ret != 1) | |
12e26265 | 650 | return -EINVAL; |
9005b650 | 651 | |
7e6fdd4b | 652 | df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value); |
9005b650 MH |
653 | ret = count; |
654 | ||
9005b650 MH |
655 | return ret; |
656 | } | |
657 | ||
6530b9de MH |
658 | static ssize_t store_min_freq(struct device *dev, struct device_attribute *attr, |
659 | const char *buf, size_t count) | |
660 | { | |
661 | struct devfreq *df = to_devfreq(dev); | |
662 | unsigned long value; | |
663 | int ret; | |
664 | unsigned long max; | |
665 | ||
666 | ret = sscanf(buf, "%lu", &value); | |
667 | if (ret != 1) | |
12e26265 | 668 | return -EINVAL; |
6530b9de MH |
669 | |
670 | mutex_lock(&df->lock); | |
671 | max = df->max_freq; | |
672 | if (value && max && value > max) { | |
673 | ret = -EINVAL; | |
674 | goto unlock; | |
675 | } | |
676 | ||
677 | df->min_freq = value; | |
678 | update_devfreq(df); | |
679 | ret = count; | |
680 | unlock: | |
681 | mutex_unlock(&df->lock); | |
6530b9de MH |
682 | return ret; |
683 | } | |
684 | ||
685 | static ssize_t show_min_freq(struct device *dev, struct device_attribute *attr, | |
686 | char *buf) | |
687 | { | |
688 | return sprintf(buf, "%lu\n", to_devfreq(dev)->min_freq); | |
689 | } | |
690 | ||
691 | static ssize_t store_max_freq(struct device *dev, struct device_attribute *attr, | |
692 | const char *buf, size_t count) | |
693 | { | |
694 | struct devfreq *df = to_devfreq(dev); | |
695 | unsigned long value; | |
696 | int ret; | |
697 | unsigned long min; | |
698 | ||
699 | ret = sscanf(buf, "%lu", &value); | |
700 | if (ret != 1) | |
12e26265 | 701 | return -EINVAL; |
6530b9de MH |
702 | |
703 | mutex_lock(&df->lock); | |
704 | min = df->min_freq; | |
705 | if (value && min && value < min) { | |
706 | ret = -EINVAL; | |
707 | goto unlock; | |
708 | } | |
709 | ||
710 | df->max_freq = value; | |
711 | update_devfreq(df); | |
712 | ret = count; | |
713 | unlock: | |
714 | mutex_unlock(&df->lock); | |
6530b9de MH |
715 | return ret; |
716 | } | |
717 | ||
718 | static ssize_t show_max_freq(struct device *dev, struct device_attribute *attr, | |
719 | char *buf) | |
720 | { | |
721 | return sprintf(buf, "%lu\n", to_devfreq(dev)->max_freq); | |
722 | } | |
723 | ||
d287de85 NM |
724 | static ssize_t show_available_freqs(struct device *d, |
725 | struct device_attribute *attr, | |
726 | char *buf) | |
727 | { | |
728 | struct devfreq *df = to_devfreq(d); | |
729 | struct device *dev = df->dev.parent; | |
730 | struct opp *opp; | |
731 | ssize_t count = 0; | |
732 | unsigned long freq = 0; | |
733 | ||
734 | rcu_read_lock(); | |
735 | do { | |
736 | opp = opp_find_freq_ceil(dev, &freq); | |
737 | if (IS_ERR(opp)) | |
738 | break; | |
739 | ||
740 | count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), | |
741 | "%lu ", freq); | |
742 | freq++; | |
743 | } while (1); | |
744 | rcu_read_unlock(); | |
745 | ||
746 | /* Truncate the trailing space */ | |
747 | if (count) | |
748 | count--; | |
749 | ||
750 | count += sprintf(&buf[count], "\n"); | |
751 | ||
752 | return count; | |
753 | } | |
754 | ||
e552bbaf JL |
755 | static ssize_t show_trans_table(struct device *dev, struct device_attribute *attr, |
756 | char *buf) | |
757 | { | |
758 | struct devfreq *devfreq = to_devfreq(dev); | |
759 | ssize_t len; | |
760 | int i, j, err; | |
761 | unsigned int max_state = devfreq->profile->max_state; | |
762 | ||
763 | err = devfreq_update_status(devfreq, devfreq->previous_freq); | |
764 | if (err) | |
765 | return 0; | |
766 | ||
767 | len = sprintf(buf, " From : To\n"); | |
768 | len += sprintf(buf + len, " :"); | |
769 | for (i = 0; i < max_state; i++) | |
770 | len += sprintf(buf + len, "%8u", | |
771 | devfreq->profile->freq_table[i]); | |
772 | ||
773 | len += sprintf(buf + len, " time(ms)\n"); | |
774 | ||
775 | for (i = 0; i < max_state; i++) { | |
776 | if (devfreq->profile->freq_table[i] | |
777 | == devfreq->previous_freq) { | |
778 | len += sprintf(buf + len, "*"); | |
779 | } else { | |
780 | len += sprintf(buf + len, " "); | |
781 | } | |
782 | len += sprintf(buf + len, "%8u:", | |
783 | devfreq->profile->freq_table[i]); | |
784 | for (j = 0; j < max_state; j++) | |
785 | len += sprintf(buf + len, "%8u", | |
786 | devfreq->trans_table[(i * max_state) + j]); | |
787 | len += sprintf(buf + len, "%10u\n", | |
788 | jiffies_to_msecs(devfreq->time_in_state[i])); | |
789 | } | |
790 | ||
791 | len += sprintf(buf + len, "Total transition : %u\n", | |
792 | devfreq->total_trans); | |
793 | return len; | |
794 | } | |
795 | ||
9005b650 MH |
796 | static struct device_attribute devfreq_attrs[] = { |
797 | __ATTR(governor, S_IRUGO, show_governor, NULL), | |
798 | __ATTR(cur_freq, S_IRUGO, show_freq, NULL), | |
d287de85 | 799 | __ATTR(available_frequencies, S_IRUGO, show_available_freqs, NULL), |
7f98a905 | 800 | __ATTR(target_freq, S_IRUGO, show_target_freq, NULL), |
9005b650 MH |
801 | __ATTR(polling_interval, S_IRUGO | S_IWUSR, show_polling_interval, |
802 | store_polling_interval), | |
6530b9de MH |
803 | __ATTR(min_freq, S_IRUGO | S_IWUSR, show_min_freq, store_min_freq), |
804 | __ATTR(max_freq, S_IRUGO | S_IWUSR, show_max_freq, store_max_freq), | |
e552bbaf | 805 | __ATTR(trans_stat, S_IRUGO, show_trans_table, NULL), |
9005b650 MH |
806 | { }, |
807 | }; | |
808 | ||
a3c98b8b MH |
809 | static int __init devfreq_init(void) |
810 | { | |
811 | devfreq_class = class_create(THIS_MODULE, "devfreq"); | |
812 | if (IS_ERR(devfreq_class)) { | |
813 | pr_err("%s: couldn't create class\n", __FILE__); | |
814 | return PTR_ERR(devfreq_class); | |
815 | } | |
7e6fdd4b RV |
816 | |
817 | devfreq_wq = create_freezable_workqueue("devfreq_wq"); | |
818 | if (IS_ERR(devfreq_wq)) { | |
819 | class_destroy(devfreq_class); | |
820 | pr_err("%s: couldn't create workqueue\n", __FILE__); | |
821 | return PTR_ERR(devfreq_wq); | |
822 | } | |
9005b650 | 823 | devfreq_class->dev_attrs = devfreq_attrs; |
7e6fdd4b | 824 | |
a3c98b8b MH |
825 | return 0; |
826 | } | |
827 | subsys_initcall(devfreq_init); | |
828 | ||
829 | static void __exit devfreq_exit(void) | |
830 | { | |
831 | class_destroy(devfreq_class); | |
7e6fdd4b | 832 | destroy_workqueue(devfreq_wq); |
a3c98b8b MH |
833 | } |
834 | module_exit(devfreq_exit); | |
835 | ||
836 | /* | |
837 | * The followings are helper functions for devfreq user device drivers with | |
838 | * OPP framework. | |
839 | */ | |
840 | ||
841 | /** | |
842 | * devfreq_recommended_opp() - Helper function to get proper OPP for the | |
843 | * freq value given to target callback. | |
c5b4a1c1 NM |
844 | * @dev: The devfreq user device. (parent of devfreq) |
845 | * @freq: The frequency given to target function | |
846 | * @flags: Flags handed from devfreq framework. | |
a3c98b8b MH |
847 | * |
848 | */ | |
ab5f299f MH |
849 | struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq, |
850 | u32 flags) | |
a3c98b8b | 851 | { |
ab5f299f | 852 | struct opp *opp; |
a3c98b8b | 853 | |
ab5f299f MH |
854 | if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { |
855 | /* The freq is an upper bound. opp should be lower */ | |
a3c98b8b | 856 | opp = opp_find_freq_floor(dev, freq); |
ab5f299f MH |
857 | |
858 | /* If not available, use the closest opp */ | |
859 | if (opp == ERR_PTR(-ENODEV)) | |
860 | opp = opp_find_freq_ceil(dev, freq); | |
861 | } else { | |
862 | /* The freq is an lower bound. opp should be higher */ | |
863 | opp = opp_find_freq_ceil(dev, freq); | |
864 | ||
865 | /* If not available, use the closest opp */ | |
866 | if (opp == ERR_PTR(-ENODEV)) | |
867 | opp = opp_find_freq_floor(dev, freq); | |
868 | } | |
869 | ||
a3c98b8b MH |
870 | return opp; |
871 | } | |
872 | ||
873 | /** | |
874 | * devfreq_register_opp_notifier() - Helper function to get devfreq notified | |
875 | * for any changes in the OPP availability | |
876 | * changes | |
c5b4a1c1 NM |
877 | * @dev: The devfreq user device. (parent of devfreq) |
878 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
879 | */ |
880 | int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
881 | { | |
882 | struct srcu_notifier_head *nh = opp_get_notifier(dev); | |
883 | ||
884 | if (IS_ERR(nh)) | |
885 | return PTR_ERR(nh); | |
886 | return srcu_notifier_chain_register(nh, &devfreq->nb); | |
887 | } | |
888 | ||
889 | /** | |
890 | * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq | |
891 | * notified for any changes in the OPP | |
892 | * availability changes anymore. | |
c5b4a1c1 NM |
893 | * @dev: The devfreq user device. (parent of devfreq) |
894 | * @devfreq: The devfreq object. | |
a3c98b8b MH |
895 | * |
896 | * At exit() callback of devfreq_dev_profile, this must be included if | |
897 | * devfreq_recommended_opp is used. | |
898 | */ | |
899 | int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) | |
900 | { | |
901 | struct srcu_notifier_head *nh = opp_get_notifier(dev); | |
902 | ||
903 | if (IS_ERR(nh)) | |
904 | return PTR_ERR(nh); | |
905 | return srcu_notifier_chain_unregister(nh, &devfreq->nb); | |
906 | } | |
907 | ||
908 | MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); | |
909 | MODULE_DESCRIPTION("devfreq class support"); | |
910 | MODULE_LICENSE("GPL"); |