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1/*
2 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
3 * for Non-CPU Devices.
4 *
5 * Copyright (C) 2011 Samsung Electronics
6 * MyungJoo Ham <myungjoo.ham@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/kernel.h>
14#include <linux/sched.h>
15#include <linux/errno.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <linux/stat.h>
21#include <linux/pm_opp.h>
22#include <linux/devfreq.h>
23#include <linux/workqueue.h>
24#include <linux/platform_device.h>
25#include <linux/list.h>
26#include <linux/printk.h>
27#include <linux/hrtimer.h>
28#include "governor.h"
29
30static struct class *devfreq_class;
31
32/*
33 * devfreq core provides delayed work based load monitoring helper
34 * functions. Governors can use these or can implement their own
35 * monitoring mechanism.
36 */
37static struct workqueue_struct *devfreq_wq;
38
39/* The list of all device-devfreq governors */
40static LIST_HEAD(devfreq_governor_list);
41/* The list of all device-devfreq */
42static LIST_HEAD(devfreq_list);
43static 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 */
52static struct devfreq *find_device_devfreq(struct device *dev)
53{
54 struct devfreq *tmp_devfreq;
55
56 if (IS_ERR_OR_NULL(dev)) {
57 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
58 return ERR_PTR(-EINVAL);
59 }
60 WARN(!mutex_is_locked(&devfreq_list_lock),
61 "devfreq_list_lock must be locked.");
62
63 list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
64 if (tmp_devfreq->dev.parent == dev)
65 return tmp_devfreq;
66 }
67
68 return ERR_PTR(-ENODEV);
69}
70
71/**
72 * devfreq_get_freq_level() - Lookup freq_table for the frequency
73 * @devfreq: the devfreq instance
74 * @freq: the target frequency
75 */
76static 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_set_freq_table() - Initialize freq_table for the frequency
89 * @devfreq: the devfreq instance
90 */
91static void devfreq_set_freq_table(struct devfreq *devfreq)
92{
93 struct devfreq_dev_profile *profile = devfreq->profile;
94 struct dev_pm_opp *opp;
95 unsigned long freq;
96 int i, count;
97
98 /* Initialize the freq_table from OPP table */
99 count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
100 if (count <= 0)
101 return;
102
103 profile->max_state = count;
104 profile->freq_table = devm_kcalloc(devfreq->dev.parent,
105 profile->max_state,
106 sizeof(*profile->freq_table),
107 GFP_KERNEL);
108 if (!profile->freq_table) {
109 profile->max_state = 0;
110 return;
111 }
112
113 rcu_read_lock();
114 for (i = 0, freq = 0; i < profile->max_state; i++, freq++) {
115 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq);
116 if (IS_ERR(opp)) {
117 devm_kfree(devfreq->dev.parent, profile->freq_table);
118 profile->max_state = 0;
119 rcu_read_unlock();
120 return;
121 }
122 profile->freq_table[i] = freq;
123 }
124 rcu_read_unlock();
125}
126
127/**
128 * devfreq_update_status() - Update statistics of devfreq behavior
129 * @devfreq: the devfreq instance
130 * @freq: the update target frequency
131 */
132static int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
133{
134 int lev, prev_lev, ret = 0;
135 unsigned long cur_time;
136
137 cur_time = jiffies;
138
139 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
140 if (prev_lev < 0) {
141 ret = prev_lev;
142 goto out;
143 }
144
145 devfreq->time_in_state[prev_lev] +=
146 cur_time - devfreq->last_stat_updated;
147
148 lev = devfreq_get_freq_level(devfreq, freq);
149 if (lev < 0) {
150 ret = lev;
151 goto out;
152 }
153
154 if (lev != prev_lev) {
155 devfreq->trans_table[(prev_lev *
156 devfreq->profile->max_state) + lev]++;
157 devfreq->total_trans++;
158 }
159
160out:
161 devfreq->last_stat_updated = cur_time;
162 return ret;
163}
164
165/**
166 * find_devfreq_governor() - find devfreq governor from name
167 * @name: name of the governor
168 *
169 * Search the list of devfreq governors and return the matched
170 * governor's pointer. devfreq_list_lock should be held by the caller.
171 */
172static struct devfreq_governor *find_devfreq_governor(const char *name)
173{
174 struct devfreq_governor *tmp_governor;
175
176 if (IS_ERR_OR_NULL(name)) {
177 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
178 return ERR_PTR(-EINVAL);
179 }
180 WARN(!mutex_is_locked(&devfreq_list_lock),
181 "devfreq_list_lock must be locked.");
182
183 list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
184 if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
185 return tmp_governor;
186 }
187
188 return ERR_PTR(-ENODEV);
189}
190
191/* Load monitoring helper functions for governors use */
192
193/**
194 * update_devfreq() - Reevaluate the device and configure frequency.
195 * @devfreq: the devfreq instance.
196 *
197 * Note: Lock devfreq->lock before calling update_devfreq
198 * This function is exported for governors.
199 */
200int update_devfreq(struct devfreq *devfreq)
201{
202 unsigned long freq;
203 int err = 0;
204 u32 flags = 0;
205
206 if (!mutex_is_locked(&devfreq->lock)) {
207 WARN(true, "devfreq->lock must be locked by the caller.\n");
208 return -EINVAL;
209 }
210
211 if (!devfreq->governor)
212 return -EINVAL;
213
214 /* Reevaluate the proper frequency */
215 err = devfreq->governor->get_target_freq(devfreq, &freq);
216 if (err)
217 return err;
218
219 /*
220 * Adjust the frequency with user freq and QoS.
221 *
222 * List from the highest priority
223 * max_freq
224 * min_freq
225 */
226
227 if (devfreq->min_freq && freq < devfreq->min_freq) {
228 freq = devfreq->min_freq;
229 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
230 }
231 if (devfreq->max_freq && freq > devfreq->max_freq) {
232 freq = devfreq->max_freq;
233 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
234 }
235
236 err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
237 if (err)
238 return err;
239
240 if (devfreq->profile->freq_table)
241 if (devfreq_update_status(devfreq, freq))
242 dev_err(&devfreq->dev,
243 "Couldn't update frequency transition information.\n");
244
245 devfreq->previous_freq = freq;
246 return err;
247}
248EXPORT_SYMBOL(update_devfreq);
249
250/**
251 * devfreq_monitor() - Periodically poll devfreq objects.
252 * @work: the work struct used to run devfreq_monitor periodically.
253 *
254 */
255static void devfreq_monitor(struct work_struct *work)
256{
257 int err;
258 struct devfreq *devfreq = container_of(work,
259 struct devfreq, work.work);
260
261 mutex_lock(&devfreq->lock);
262 err = update_devfreq(devfreq);
263 if (err)
264 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
265
266 queue_delayed_work(devfreq_wq, &devfreq->work,
267 msecs_to_jiffies(devfreq->profile->polling_ms));
268 mutex_unlock(&devfreq->lock);
269}
270
271/**
272 * devfreq_monitor_start() - Start load monitoring of devfreq instance
273 * @devfreq: the devfreq instance.
274 *
275 * Helper function for starting devfreq device load monitoing. By
276 * default delayed work based monitoring is supported. Function
277 * to be called from governor in response to DEVFREQ_GOV_START
278 * event when device is added to devfreq framework.
279 */
280void devfreq_monitor_start(struct devfreq *devfreq)
281{
282 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
283 if (devfreq->profile->polling_ms)
284 queue_delayed_work(devfreq_wq, &devfreq->work,
285 msecs_to_jiffies(devfreq->profile->polling_ms));
286}
287EXPORT_SYMBOL(devfreq_monitor_start);
288
289/**
290 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
291 * @devfreq: the devfreq instance.
292 *
293 * Helper function to stop devfreq device load monitoing. Function
294 * to be called from governor in response to DEVFREQ_GOV_STOP
295 * event when device is removed from devfreq framework.
296 */
297void devfreq_monitor_stop(struct devfreq *devfreq)
298{
299 cancel_delayed_work_sync(&devfreq->work);
300}
301EXPORT_SYMBOL(devfreq_monitor_stop);
302
303/**
304 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
305 * @devfreq: the devfreq instance.
306 *
307 * Helper function to suspend devfreq device load monitoing. Function
308 * to be called from governor in response to DEVFREQ_GOV_SUSPEND
309 * event or when polling interval is set to zero.
310 *
311 * Note: Though this function is same as devfreq_monitor_stop(),
312 * intentionally kept separate to provide hooks for collecting
313 * transition statistics.
314 */
315void devfreq_monitor_suspend(struct devfreq *devfreq)
316{
317 mutex_lock(&devfreq->lock);
318 if (devfreq->stop_polling) {
319 mutex_unlock(&devfreq->lock);
320 return;
321 }
322
323 devfreq_update_status(devfreq, devfreq->previous_freq);
324 devfreq->stop_polling = true;
325 mutex_unlock(&devfreq->lock);
326 cancel_delayed_work_sync(&devfreq->work);
327}
328EXPORT_SYMBOL(devfreq_monitor_suspend);
329
330/**
331 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
332 * @devfreq: the devfreq instance.
333 *
334 * Helper function to resume devfreq device load monitoing. Function
335 * to be called from governor in response to DEVFREQ_GOV_RESUME
336 * event or when polling interval is set to non-zero.
337 */
338void devfreq_monitor_resume(struct devfreq *devfreq)
339{
340 unsigned long freq;
341
342 mutex_lock(&devfreq->lock);
343 if (!devfreq->stop_polling)
344 goto out;
345
346 if (!delayed_work_pending(&devfreq->work) &&
347 devfreq->profile->polling_ms)
348 queue_delayed_work(devfreq_wq, &devfreq->work,
349 msecs_to_jiffies(devfreq->profile->polling_ms));
350
351 devfreq->last_stat_updated = jiffies;
352 devfreq->stop_polling = false;
353
354 if (devfreq->profile->get_cur_freq &&
355 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
356 devfreq->previous_freq = freq;
357
358out:
359 mutex_unlock(&devfreq->lock);
360}
361EXPORT_SYMBOL(devfreq_monitor_resume);
362
363/**
364 * devfreq_interval_update() - Update device devfreq monitoring interval
365 * @devfreq: the devfreq instance.
366 * @delay: new polling interval to be set.
367 *
368 * Helper function to set new load monitoring polling interval. Function
369 * to be called from governor in response to DEVFREQ_GOV_INTERVAL event.
370 */
371void devfreq_interval_update(struct devfreq *devfreq, unsigned int *delay)
372{
373 unsigned int cur_delay = devfreq->profile->polling_ms;
374 unsigned int new_delay = *delay;
375
376 mutex_lock(&devfreq->lock);
377 devfreq->profile->polling_ms = new_delay;
378
379 if (devfreq->stop_polling)
380 goto out;
381
382 /* if new delay is zero, stop polling */
383 if (!new_delay) {
384 mutex_unlock(&devfreq->lock);
385 cancel_delayed_work_sync(&devfreq->work);
386 return;
387 }
388
389 /* if current delay is zero, start polling with new delay */
390 if (!cur_delay) {
391 queue_delayed_work(devfreq_wq, &devfreq->work,
392 msecs_to_jiffies(devfreq->profile->polling_ms));
393 goto out;
394 }
395
396 /* if current delay is greater than new delay, restart polling */
397 if (cur_delay > new_delay) {
398 mutex_unlock(&devfreq->lock);
399 cancel_delayed_work_sync(&devfreq->work);
400 mutex_lock(&devfreq->lock);
401 if (!devfreq->stop_polling)
402 queue_delayed_work(devfreq_wq, &devfreq->work,
403 msecs_to_jiffies(devfreq->profile->polling_ms));
404 }
405out:
406 mutex_unlock(&devfreq->lock);
407}
408EXPORT_SYMBOL(devfreq_interval_update);
409
410/**
411 * devfreq_notifier_call() - Notify that the device frequency requirements
412 * has been changed out of devfreq framework.
413 * @nb: the notifier_block (supposed to be devfreq->nb)
414 * @type: not used
415 * @devp: not used
416 *
417 * Called by a notifier that uses devfreq->nb.
418 */
419static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
420 void *devp)
421{
422 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
423 int ret;
424
425 mutex_lock(&devfreq->lock);
426 ret = update_devfreq(devfreq);
427 mutex_unlock(&devfreq->lock);
428
429 return ret;
430}
431
432/**
433 * _remove_devfreq() - Remove devfreq from the list and release its resources.
434 * @devfreq: the devfreq struct
435 */
436static void _remove_devfreq(struct devfreq *devfreq)
437{
438 mutex_lock(&devfreq_list_lock);
439 if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
440 mutex_unlock(&devfreq_list_lock);
441 dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
442 return;
443 }
444 list_del(&devfreq->node);
445 mutex_unlock(&devfreq_list_lock);
446
447 if (devfreq->governor)
448 devfreq->governor->event_handler(devfreq,
449 DEVFREQ_GOV_STOP, NULL);
450
451 if (devfreq->profile->exit)
452 devfreq->profile->exit(devfreq->dev.parent);
453
454 mutex_destroy(&devfreq->lock);
455 kfree(devfreq);
456}
457
458/**
459 * devfreq_dev_release() - Callback for struct device to release the device.
460 * @dev: the devfreq device
461 *
462 * This calls _remove_devfreq() if _remove_devfreq() is not called.
463 */
464static void devfreq_dev_release(struct device *dev)
465{
466 struct devfreq *devfreq = to_devfreq(dev);
467
468 _remove_devfreq(devfreq);
469}
470
471/**
472 * devfreq_add_device() - Add devfreq feature to the device
473 * @dev: the device to add devfreq feature.
474 * @profile: device-specific profile to run devfreq.
475 * @governor_name: name of the policy to choose frequency.
476 * @data: private data for the governor. The devfreq framework does not
477 * touch this value.
478 */
479struct devfreq *devfreq_add_device(struct device *dev,
480 struct devfreq_dev_profile *profile,
481 const char *governor_name,
482 void *data)
483{
484 struct devfreq *devfreq;
485 struct devfreq_governor *governor;
486 int err = 0;
487
488 if (!dev || !profile || !governor_name) {
489 dev_err(dev, "%s: Invalid parameters.\n", __func__);
490 return ERR_PTR(-EINVAL);
491 }
492
493 mutex_lock(&devfreq_list_lock);
494 devfreq = find_device_devfreq(dev);
495 mutex_unlock(&devfreq_list_lock);
496 if (!IS_ERR(devfreq)) {
497 dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__);
498 err = -EINVAL;
499 goto err_out;
500 }
501
502 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
503 if (!devfreq) {
504 dev_err(dev, "%s: Unable to create devfreq for the device\n",
505 __func__);
506 err = -ENOMEM;
507 goto err_out;
508 }
509
510 mutex_init(&devfreq->lock);
511 mutex_lock(&devfreq->lock);
512 devfreq->dev.parent = dev;
513 devfreq->dev.class = devfreq_class;
514 devfreq->dev.release = devfreq_dev_release;
515 devfreq->profile = profile;
516 strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
517 devfreq->previous_freq = profile->initial_freq;
518 devfreq->data = data;
519 devfreq->nb.notifier_call = devfreq_notifier_call;
520
521 if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
522 mutex_unlock(&devfreq->lock);
523 devfreq_set_freq_table(devfreq);
524 mutex_lock(&devfreq->lock);
525 }
526
527 devfreq->trans_table = devm_kzalloc(dev, sizeof(unsigned int) *
528 devfreq->profile->max_state *
529 devfreq->profile->max_state,
530 GFP_KERNEL);
531 devfreq->time_in_state = devm_kzalloc(dev, sizeof(unsigned long) *
532 devfreq->profile->max_state,
533 GFP_KERNEL);
534 devfreq->last_stat_updated = jiffies;
535
536 dev_set_name(&devfreq->dev, "%s", dev_name(dev));
537 err = device_register(&devfreq->dev);
538 if (err) {
539 put_device(&devfreq->dev);
540 mutex_unlock(&devfreq->lock);
541 goto err_out;
542 }
543
544 mutex_unlock(&devfreq->lock);
545
546 mutex_lock(&devfreq_list_lock);
547 list_add(&devfreq->node, &devfreq_list);
548
549 governor = find_devfreq_governor(devfreq->governor_name);
550 if (!IS_ERR(governor))
551 devfreq->governor = governor;
552 if (devfreq->governor)
553 err = devfreq->governor->event_handler(devfreq,
554 DEVFREQ_GOV_START, NULL);
555 mutex_unlock(&devfreq_list_lock);
556 if (err) {
557 dev_err(dev, "%s: Unable to start governor for the device\n",
558 __func__);
559 goto err_init;
560 }
561
562 return devfreq;
563
564err_init:
565 list_del(&devfreq->node);
566 device_unregister(&devfreq->dev);
567 kfree(devfreq);
568err_out:
569 return ERR_PTR(err);
570}
571EXPORT_SYMBOL(devfreq_add_device);
572
573/**
574 * devfreq_remove_device() - Remove devfreq feature from a device.
575 * @devfreq: the devfreq instance to be removed
576 *
577 * The opposite of devfreq_add_device().
578 */
579int devfreq_remove_device(struct devfreq *devfreq)
580{
581 if (!devfreq)
582 return -EINVAL;
583
584 device_unregister(&devfreq->dev);
585 put_device(&devfreq->dev);
586
587 return 0;
588}
589EXPORT_SYMBOL(devfreq_remove_device);
590
591static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
592{
593 struct devfreq **r = res;
594
595 if (WARN_ON(!r || !*r))
596 return 0;
597
598 return *r == data;
599}
600
601static void devm_devfreq_dev_release(struct device *dev, void *res)
602{
603 devfreq_remove_device(*(struct devfreq **)res);
604}
605
606/**
607 * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
608 * @dev: the device to add devfreq feature.
609 * @profile: device-specific profile to run devfreq.
610 * @governor_name: name of the policy to choose frequency.
611 * @data: private data for the governor. The devfreq framework does not
612 * touch this value.
613 *
614 * This function manages automatically the memory of devfreq device using device
615 * resource management and simplify the free operation for memory of devfreq
616 * device.
617 */
618struct devfreq *devm_devfreq_add_device(struct device *dev,
619 struct devfreq_dev_profile *profile,
620 const char *governor_name,
621 void *data)
622{
623 struct devfreq **ptr, *devfreq;
624
625 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
626 if (!ptr)
627 return ERR_PTR(-ENOMEM);
628
629 devfreq = devfreq_add_device(dev, profile, governor_name, data);
630 if (IS_ERR(devfreq)) {
631 devres_free(ptr);
632 return ERR_PTR(-ENOMEM);
633 }
634
635 *ptr = devfreq;
636 devres_add(dev, ptr);
637
638 return devfreq;
639}
640EXPORT_SYMBOL(devm_devfreq_add_device);
641
642/**
643 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
644 * @dev: the device to add devfreq feature.
645 * @devfreq: the devfreq instance to be removed
646 */
647void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
648{
649 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
650 devm_devfreq_dev_match, devfreq));
651}
652EXPORT_SYMBOL(devm_devfreq_remove_device);
653
654/**
655 * devfreq_suspend_device() - Suspend devfreq of a device.
656 * @devfreq: the devfreq instance to be suspended
657 *
658 * This function is intended to be called by the pm callbacks
659 * (e.g., runtime_suspend, suspend) of the device driver that
660 * holds the devfreq.
661 */
662int devfreq_suspend_device(struct devfreq *devfreq)
663{
664 if (!devfreq)
665 return -EINVAL;
666
667 if (!devfreq->governor)
668 return 0;
669
670 return devfreq->governor->event_handler(devfreq,
671 DEVFREQ_GOV_SUSPEND, NULL);
672}
673EXPORT_SYMBOL(devfreq_suspend_device);
674
675/**
676 * devfreq_resume_device() - Resume devfreq of a device.
677 * @devfreq: the devfreq instance to be resumed
678 *
679 * This function is intended to be called by the pm callbacks
680 * (e.g., runtime_resume, resume) of the device driver that
681 * holds the devfreq.
682 */
683int devfreq_resume_device(struct devfreq *devfreq)
684{
685 if (!devfreq)
686 return -EINVAL;
687
688 if (!devfreq->governor)
689 return 0;
690
691 return devfreq->governor->event_handler(devfreq,
692 DEVFREQ_GOV_RESUME, NULL);
693}
694EXPORT_SYMBOL(devfreq_resume_device);
695
696/**
697 * devfreq_add_governor() - Add devfreq governor
698 * @governor: the devfreq governor to be added
699 */
700int devfreq_add_governor(struct devfreq_governor *governor)
701{
702 struct devfreq_governor *g;
703 struct devfreq *devfreq;
704 int err = 0;
705
706 if (!governor) {
707 pr_err("%s: Invalid parameters.\n", __func__);
708 return -EINVAL;
709 }
710
711 mutex_lock(&devfreq_list_lock);
712 g = find_devfreq_governor(governor->name);
713 if (!IS_ERR(g)) {
714 pr_err("%s: governor %s already registered\n", __func__,
715 g->name);
716 err = -EINVAL;
717 goto err_out;
718 }
719
720 list_add(&governor->node, &devfreq_governor_list);
721
722 list_for_each_entry(devfreq, &devfreq_list, node) {
723 int ret = 0;
724 struct device *dev = devfreq->dev.parent;
725
726 if (!strncmp(devfreq->governor_name, governor->name,
727 DEVFREQ_NAME_LEN)) {
728 /* The following should never occur */
729 if (devfreq->governor) {
730 dev_warn(dev,
731 "%s: Governor %s already present\n",
732 __func__, devfreq->governor->name);
733 ret = devfreq->governor->event_handler(devfreq,
734 DEVFREQ_GOV_STOP, NULL);
735 if (ret) {
736 dev_warn(dev,
737 "%s: Governor %s stop = %d\n",
738 __func__,
739 devfreq->governor->name, ret);
740 }
741 /* Fall through */
742 }
743 devfreq->governor = governor;
744 ret = devfreq->governor->event_handler(devfreq,
745 DEVFREQ_GOV_START, NULL);
746 if (ret) {
747 dev_warn(dev, "%s: Governor %s start=%d\n",
748 __func__, devfreq->governor->name,
749 ret);
750 }
751 }
752 }
753
754err_out:
755 mutex_unlock(&devfreq_list_lock);
756
757 return err;
758}
759EXPORT_SYMBOL(devfreq_add_governor);
760
761/**
762 * devfreq_remove_device() - Remove devfreq feature from a device.
763 * @governor: the devfreq governor to be removed
764 */
765int devfreq_remove_governor(struct devfreq_governor *governor)
766{
767 struct devfreq_governor *g;
768 struct devfreq *devfreq;
769 int err = 0;
770
771 if (!governor) {
772 pr_err("%s: Invalid parameters.\n", __func__);
773 return -EINVAL;
774 }
775
776 mutex_lock(&devfreq_list_lock);
777 g = find_devfreq_governor(governor->name);
778 if (IS_ERR(g)) {
779 pr_err("%s: governor %s not registered\n", __func__,
780 governor->name);
781 err = PTR_ERR(g);
782 goto err_out;
783 }
784 list_for_each_entry(devfreq, &devfreq_list, node) {
785 int ret;
786 struct device *dev = devfreq->dev.parent;
787
788 if (!strncmp(devfreq->governor_name, governor->name,
789 DEVFREQ_NAME_LEN)) {
790 /* we should have a devfreq governor! */
791 if (!devfreq->governor) {
792 dev_warn(dev, "%s: Governor %s NOT present\n",
793 __func__, governor->name);
794 continue;
795 /* Fall through */
796 }
797 ret = devfreq->governor->event_handler(devfreq,
798 DEVFREQ_GOV_STOP, NULL);
799 if (ret) {
800 dev_warn(dev, "%s: Governor %s stop=%d\n",
801 __func__, devfreq->governor->name,
802 ret);
803 }
804 devfreq->governor = NULL;
805 }
806 }
807
808 list_del(&governor->node);
809err_out:
810 mutex_unlock(&devfreq_list_lock);
811
812 return err;
813}
814EXPORT_SYMBOL(devfreq_remove_governor);
815
816static ssize_t governor_show(struct device *dev,
817 struct device_attribute *attr, char *buf)
818{
819 if (!to_devfreq(dev)->governor)
820 return -EINVAL;
821
822 return sprintf(buf, "%s\n", to_devfreq(dev)->governor->name);
823}
824
825static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
826 const char *buf, size_t count)
827{
828 struct devfreq *df = to_devfreq(dev);
829 int ret;
830 char str_governor[DEVFREQ_NAME_LEN + 1];
831 struct devfreq_governor *governor;
832
833 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
834 if (ret != 1)
835 return -EINVAL;
836
837 mutex_lock(&devfreq_list_lock);
838 governor = find_devfreq_governor(str_governor);
839 if (IS_ERR(governor)) {
840 ret = PTR_ERR(governor);
841 goto out;
842 }
843 if (df->governor == governor) {
844 ret = 0;
845 goto out;
846 }
847
848 if (df->governor) {
849 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
850 if (ret) {
851 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
852 __func__, df->governor->name, ret);
853 goto out;
854 }
855 }
856 df->governor = governor;
857 strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
858 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
859 if (ret)
860 dev_warn(dev, "%s: Governor %s not started(%d)\n",
861 __func__, df->governor->name, ret);
862out:
863 mutex_unlock(&devfreq_list_lock);
864
865 if (!ret)
866 ret = count;
867 return ret;
868}
869static DEVICE_ATTR_RW(governor);
870
871static ssize_t available_governors_show(struct device *d,
872 struct device_attribute *attr,
873 char *buf)
874{
875 struct devfreq_governor *tmp_governor;
876 ssize_t count = 0;
877
878 mutex_lock(&devfreq_list_lock);
879 list_for_each_entry(tmp_governor, &devfreq_governor_list, node)
880 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
881 "%s ", tmp_governor->name);
882 mutex_unlock(&devfreq_list_lock);
883
884 /* Truncate the trailing space */
885 if (count)
886 count--;
887
888 count += sprintf(&buf[count], "\n");
889
890 return count;
891}
892static DEVICE_ATTR_RO(available_governors);
893
894static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
895 char *buf)
896{
897 unsigned long freq;
898 struct devfreq *devfreq = to_devfreq(dev);
899
900 if (devfreq->profile->get_cur_freq &&
901 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
902 return sprintf(buf, "%lu\n", freq);
903
904 return sprintf(buf, "%lu\n", devfreq->previous_freq);
905}
906static DEVICE_ATTR_RO(cur_freq);
907
908static ssize_t target_freq_show(struct device *dev,
909 struct device_attribute *attr, char *buf)
910{
911 return sprintf(buf, "%lu\n", to_devfreq(dev)->previous_freq);
912}
913static DEVICE_ATTR_RO(target_freq);
914
915static ssize_t polling_interval_show(struct device *dev,
916 struct device_attribute *attr, char *buf)
917{
918 return sprintf(buf, "%d\n", to_devfreq(dev)->profile->polling_ms);
919}
920
921static ssize_t polling_interval_store(struct device *dev,
922 struct device_attribute *attr,
923 const char *buf, size_t count)
924{
925 struct devfreq *df = to_devfreq(dev);
926 unsigned int value;
927 int ret;
928
929 if (!df->governor)
930 return -EINVAL;
931
932 ret = sscanf(buf, "%u", &value);
933 if (ret != 1)
934 return -EINVAL;
935
936 df->governor->event_handler(df, DEVFREQ_GOV_INTERVAL, &value);
937 ret = count;
938
939 return ret;
940}
941static DEVICE_ATTR_RW(polling_interval);
942
943static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
944 const char *buf, size_t count)
945{
946 struct devfreq *df = to_devfreq(dev);
947 unsigned long value;
948 int ret;
949 unsigned long max;
950
951 ret = sscanf(buf, "%lu", &value);
952 if (ret != 1)
953 return -EINVAL;
954
955 mutex_lock(&df->lock);
956 max = df->max_freq;
957 if (value && max && value > max) {
958 ret = -EINVAL;
959 goto unlock;
960 }
961
962 df->min_freq = value;
963 update_devfreq(df);
964 ret = count;
965unlock:
966 mutex_unlock(&df->lock);
967 return ret;
968}
969
970static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
971 const char *buf, size_t count)
972{
973 struct devfreq *df = to_devfreq(dev);
974 unsigned long value;
975 int ret;
976 unsigned long min;
977
978 ret = sscanf(buf, "%lu", &value);
979 if (ret != 1)
980 return -EINVAL;
981
982 mutex_lock(&df->lock);
983 min = df->min_freq;
984 if (value && min && value < min) {
985 ret = -EINVAL;
986 goto unlock;
987 }
988
989 df->max_freq = value;
990 update_devfreq(df);
991 ret = count;
992unlock:
993 mutex_unlock(&df->lock);
994 return ret;
995}
996
997#define show_one(name) \
998static ssize_t name##_show \
999(struct device *dev, struct device_attribute *attr, char *buf) \
1000{ \
1001 return sprintf(buf, "%lu\n", to_devfreq(dev)->name); \
1002}
1003show_one(min_freq);
1004show_one(max_freq);
1005
1006static DEVICE_ATTR_RW(min_freq);
1007static DEVICE_ATTR_RW(max_freq);
1008
1009static ssize_t available_frequencies_show(struct device *d,
1010 struct device_attribute *attr,
1011 char *buf)
1012{
1013 struct devfreq *df = to_devfreq(d);
1014 struct device *dev = df->dev.parent;
1015 struct dev_pm_opp *opp;
1016 ssize_t count = 0;
1017 unsigned long freq = 0;
1018
1019 rcu_read_lock();
1020 do {
1021 opp = dev_pm_opp_find_freq_ceil(dev, &freq);
1022 if (IS_ERR(opp))
1023 break;
1024
1025 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1026 "%lu ", freq);
1027 freq++;
1028 } while (1);
1029 rcu_read_unlock();
1030
1031 /* Truncate the trailing space */
1032 if (count)
1033 count--;
1034
1035 count += sprintf(&buf[count], "\n");
1036
1037 return count;
1038}
1039static DEVICE_ATTR_RO(available_frequencies);
1040
1041static ssize_t trans_stat_show(struct device *dev,
1042 struct device_attribute *attr, char *buf)
1043{
1044 struct devfreq *devfreq = to_devfreq(dev);
1045 ssize_t len;
1046 int i, j;
1047 unsigned int max_state = devfreq->profile->max_state;
1048
1049 if (!devfreq->stop_polling &&
1050 devfreq_update_status(devfreq, devfreq->previous_freq))
1051 return 0;
1052 if (max_state == 0)
1053 return sprintf(buf, "Not Supported.\n");
1054
1055 len = sprintf(buf, " From : To\n");
1056 len += sprintf(buf + len, " :");
1057 for (i = 0; i < max_state; i++)
1058 len += sprintf(buf + len, "%10lu",
1059 devfreq->profile->freq_table[i]);
1060
1061 len += sprintf(buf + len, " time(ms)\n");
1062
1063 for (i = 0; i < max_state; i++) {
1064 if (devfreq->profile->freq_table[i]
1065 == devfreq->previous_freq) {
1066 len += sprintf(buf + len, "*");
1067 } else {
1068 len += sprintf(buf + len, " ");
1069 }
1070 len += sprintf(buf + len, "%10lu:",
1071 devfreq->profile->freq_table[i]);
1072 for (j = 0; j < max_state; j++)
1073 len += sprintf(buf + len, "%10u",
1074 devfreq->trans_table[(i * max_state) + j]);
1075 len += sprintf(buf + len, "%10u\n",
1076 jiffies_to_msecs(devfreq->time_in_state[i]));
1077 }
1078
1079 len += sprintf(buf + len, "Total transition : %u\n",
1080 devfreq->total_trans);
1081 return len;
1082}
1083static DEVICE_ATTR_RO(trans_stat);
1084
1085static struct attribute *devfreq_attrs[] = {
1086 &dev_attr_governor.attr,
1087 &dev_attr_available_governors.attr,
1088 &dev_attr_cur_freq.attr,
1089 &dev_attr_available_frequencies.attr,
1090 &dev_attr_target_freq.attr,
1091 &dev_attr_polling_interval.attr,
1092 &dev_attr_min_freq.attr,
1093 &dev_attr_max_freq.attr,
1094 &dev_attr_trans_stat.attr,
1095 NULL,
1096};
1097ATTRIBUTE_GROUPS(devfreq);
1098
1099static int __init devfreq_init(void)
1100{
1101 devfreq_class = class_create(THIS_MODULE, "devfreq");
1102 if (IS_ERR(devfreq_class)) {
1103 pr_err("%s: couldn't create class\n", __FILE__);
1104 return PTR_ERR(devfreq_class);
1105 }
1106
1107 devfreq_wq = create_freezable_workqueue("devfreq_wq");
1108 if (!devfreq_wq) {
1109 class_destroy(devfreq_class);
1110 pr_err("%s: couldn't create workqueue\n", __FILE__);
1111 return -ENOMEM;
1112 }
1113 devfreq_class->dev_groups = devfreq_groups;
1114
1115 return 0;
1116}
1117subsys_initcall(devfreq_init);
1118
1119static void __exit devfreq_exit(void)
1120{
1121 class_destroy(devfreq_class);
1122 destroy_workqueue(devfreq_wq);
1123}
1124module_exit(devfreq_exit);
1125
1126/*
1127 * The followings are helper functions for devfreq user device drivers with
1128 * OPP framework.
1129 */
1130
1131/**
1132 * devfreq_recommended_opp() - Helper function to get proper OPP for the
1133 * freq value given to target callback.
1134 * @dev: The devfreq user device. (parent of devfreq)
1135 * @freq: The frequency given to target function
1136 * @flags: Flags handed from devfreq framework.
1137 *
1138 * Locking: This function must be called under rcu_read_lock(). opp is a rcu
1139 * protected pointer. The reason for the same is that the opp pointer which is
1140 * returned will remain valid for use with opp_get_{voltage, freq} only while
1141 * under the locked area. The pointer returned must be used prior to unlocking
1142 * with rcu_read_unlock() to maintain the integrity of the pointer.
1143 */
1144struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
1145 unsigned long *freq,
1146 u32 flags)
1147{
1148 struct dev_pm_opp *opp;
1149
1150 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
1151 /* The freq is an upper bound. opp should be lower */
1152 opp = dev_pm_opp_find_freq_floor(dev, freq);
1153
1154 /* If not available, use the closest opp */
1155 if (opp == ERR_PTR(-ERANGE))
1156 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1157 } else {
1158 /* The freq is an lower bound. opp should be higher */
1159 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1160
1161 /* If not available, use the closest opp */
1162 if (opp == ERR_PTR(-ERANGE))
1163 opp = dev_pm_opp_find_freq_floor(dev, freq);
1164 }
1165
1166 return opp;
1167}
1168EXPORT_SYMBOL(devfreq_recommended_opp);
1169
1170/**
1171 * devfreq_register_opp_notifier() - Helper function to get devfreq notified
1172 * for any changes in the OPP availability
1173 * changes
1174 * @dev: The devfreq user device. (parent of devfreq)
1175 * @devfreq: The devfreq object.
1176 */
1177int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
1178{
1179 struct srcu_notifier_head *nh;
1180 int ret = 0;
1181
1182 rcu_read_lock();
1183 nh = dev_pm_opp_get_notifier(dev);
1184 if (IS_ERR(nh))
1185 ret = PTR_ERR(nh);
1186 rcu_read_unlock();
1187 if (!ret)
1188 ret = srcu_notifier_chain_register(nh, &devfreq->nb);
1189
1190 return ret;
1191}
1192EXPORT_SYMBOL(devfreq_register_opp_notifier);
1193
1194/**
1195 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
1196 * notified for any changes in the OPP
1197 * availability changes anymore.
1198 * @dev: The devfreq user device. (parent of devfreq)
1199 * @devfreq: The devfreq object.
1200 *
1201 * At exit() callback of devfreq_dev_profile, this must be included if
1202 * devfreq_recommended_opp is used.
1203 */
1204int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
1205{
1206 struct srcu_notifier_head *nh;
1207 int ret = 0;
1208
1209 rcu_read_lock();
1210 nh = dev_pm_opp_get_notifier(dev);
1211 if (IS_ERR(nh))
1212 ret = PTR_ERR(nh);
1213 rcu_read_unlock();
1214 if (!ret)
1215 ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
1216
1217 return ret;
1218}
1219EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
1220
1221static void devm_devfreq_opp_release(struct device *dev, void *res)
1222{
1223 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
1224}
1225
1226/**
1227 * devm_ devfreq_register_opp_notifier()
1228 * - Resource-managed devfreq_register_opp_notifier()
1229 * @dev: The devfreq user device. (parent of devfreq)
1230 * @devfreq: The devfreq object.
1231 */
1232int devm_devfreq_register_opp_notifier(struct device *dev,
1233 struct devfreq *devfreq)
1234{
1235 struct devfreq **ptr;
1236 int ret;
1237
1238 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
1239 if (!ptr)
1240 return -ENOMEM;
1241
1242 ret = devfreq_register_opp_notifier(dev, devfreq);
1243 if (ret) {
1244 devres_free(ptr);
1245 return ret;
1246 }
1247
1248 *ptr = devfreq;
1249 devres_add(dev, ptr);
1250
1251 return 0;
1252}
1253EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
1254
1255/**
1256 * devm_devfreq_unregister_opp_notifier()
1257 * - Resource-managed devfreq_unregister_opp_notifier()
1258 * @dev: The devfreq user device. (parent of devfreq)
1259 * @devfreq: The devfreq object.
1260 */
1261void devm_devfreq_unregister_opp_notifier(struct device *dev,
1262 struct devfreq *devfreq)
1263{
1264 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
1265 devm_devfreq_dev_match, devfreq));
1266}
1267EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
1268
1269MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
1270MODULE_DESCRIPTION("devfreq class support");
1271MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
4 * for Non-CPU Devices.
5 *
6 * Copyright (C) 2011 Samsung Electronics
7 * MyungJoo Ham <myungjoo.ham@samsung.com>
8 */
9
10#include <linux/kernel.h>
11#include <linux/kmod.h>
12#include <linux/sched.h>
13#include <linux/debugfs.h>
14#include <linux/devfreq_cooling.h>
15#include <linux/errno.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/export.h>
19#include <linux/slab.h>
20#include <linux/stat.h>
21#include <linux/pm_opp.h>
22#include <linux/devfreq.h>
23#include <linux/workqueue.h>
24#include <linux/platform_device.h>
25#include <linux/list.h>
26#include <linux/printk.h>
27#include <linux/hrtimer.h>
28#include <linux/of.h>
29#include <linux/pm_qos.h>
30#include <linux/units.h>
31#include "governor.h"
32
33#define CREATE_TRACE_POINTS
34#include <trace/events/devfreq.h>
35
36#define IS_SUPPORTED_FLAG(f, name) ((f & DEVFREQ_GOV_FLAG_##name) ? true : false)
37#define IS_SUPPORTED_ATTR(f, name) ((f & DEVFREQ_GOV_ATTR_##name) ? true : false)
38
39static struct class *devfreq_class;
40static struct dentry *devfreq_debugfs;
41
42/*
43 * devfreq core provides delayed work based load monitoring helper
44 * functions. Governors can use these or can implement their own
45 * monitoring mechanism.
46 */
47static struct workqueue_struct *devfreq_wq;
48
49/* The list of all device-devfreq governors */
50static LIST_HEAD(devfreq_governor_list);
51/* The list of all device-devfreq */
52static LIST_HEAD(devfreq_list);
53static DEFINE_MUTEX(devfreq_list_lock);
54
55static const char timer_name[][DEVFREQ_NAME_LEN] = {
56 [DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" },
57 [DEVFREQ_TIMER_DELAYED] = { "delayed" },
58};
59
60/**
61 * find_device_devfreq() - find devfreq struct using device pointer
62 * @dev: device pointer used to lookup device devfreq.
63 *
64 * Search the list of device devfreqs and return the matched device's
65 * devfreq info. devfreq_list_lock should be held by the caller.
66 */
67static struct devfreq *find_device_devfreq(struct device *dev)
68{
69 struct devfreq *tmp_devfreq;
70
71 lockdep_assert_held(&devfreq_list_lock);
72
73 if (IS_ERR_OR_NULL(dev)) {
74 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
75 return ERR_PTR(-EINVAL);
76 }
77
78 list_for_each_entry(tmp_devfreq, &devfreq_list, node) {
79 if (tmp_devfreq->dev.parent == dev)
80 return tmp_devfreq;
81 }
82
83 return ERR_PTR(-ENODEV);
84}
85
86static unsigned long find_available_min_freq(struct devfreq *devfreq)
87{
88 struct dev_pm_opp *opp;
89 unsigned long min_freq = 0;
90
91 opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &min_freq, 0);
92 if (IS_ERR(opp))
93 min_freq = 0;
94 else
95 dev_pm_opp_put(opp);
96
97 return min_freq;
98}
99
100static unsigned long find_available_max_freq(struct devfreq *devfreq)
101{
102 struct dev_pm_opp *opp;
103 unsigned long max_freq = ULONG_MAX;
104
105 opp = dev_pm_opp_find_freq_floor_indexed(devfreq->dev.parent, &max_freq, 0);
106 if (IS_ERR(opp))
107 max_freq = 0;
108 else
109 dev_pm_opp_put(opp);
110
111 return max_freq;
112}
113
114/**
115 * devfreq_get_freq_range() - Get the current freq range
116 * @devfreq: the devfreq instance
117 * @min_freq: the min frequency
118 * @max_freq: the max frequency
119 *
120 * This takes into consideration all constraints.
121 */
122void devfreq_get_freq_range(struct devfreq *devfreq,
123 unsigned long *min_freq,
124 unsigned long *max_freq)
125{
126 unsigned long *freq_table = devfreq->freq_table;
127 s32 qos_min_freq, qos_max_freq;
128
129 lockdep_assert_held(&devfreq->lock);
130
131 /*
132 * Initialize minimum/maximum frequency from freq table.
133 * The devfreq drivers can initialize this in either ascending or
134 * descending order and devfreq core supports both.
135 */
136 if (freq_table[0] < freq_table[devfreq->max_state - 1]) {
137 *min_freq = freq_table[0];
138 *max_freq = freq_table[devfreq->max_state - 1];
139 } else {
140 *min_freq = freq_table[devfreq->max_state - 1];
141 *max_freq = freq_table[0];
142 }
143
144 /* Apply constraints from PM QoS */
145 qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent,
146 DEV_PM_QOS_MIN_FREQUENCY);
147 qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent,
148 DEV_PM_QOS_MAX_FREQUENCY);
149 *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq);
150 if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE)
151 *max_freq = min(*max_freq,
152 (unsigned long)HZ_PER_KHZ * qos_max_freq);
153
154 /* Apply constraints from OPP interface */
155 *min_freq = max(*min_freq, devfreq->scaling_min_freq);
156 *max_freq = min(*max_freq, devfreq->scaling_max_freq);
157
158 if (*min_freq > *max_freq)
159 *min_freq = *max_freq;
160}
161EXPORT_SYMBOL(devfreq_get_freq_range);
162
163/**
164 * devfreq_get_freq_level() - Lookup freq_table for the frequency
165 * @devfreq: the devfreq instance
166 * @freq: the target frequency
167 */
168static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)
169{
170 int lev;
171
172 for (lev = 0; lev < devfreq->max_state; lev++)
173 if (freq == devfreq->freq_table[lev])
174 return lev;
175
176 return -EINVAL;
177}
178
179static int set_freq_table(struct devfreq *devfreq)
180{
181 struct dev_pm_opp *opp;
182 unsigned long freq;
183 int i, count;
184
185 /* Initialize the freq_table from OPP table */
186 count = dev_pm_opp_get_opp_count(devfreq->dev.parent);
187 if (count <= 0)
188 return -EINVAL;
189
190 devfreq->max_state = count;
191 devfreq->freq_table = devm_kcalloc(devfreq->dev.parent,
192 devfreq->max_state,
193 sizeof(*devfreq->freq_table),
194 GFP_KERNEL);
195 if (!devfreq->freq_table)
196 return -ENOMEM;
197
198 for (i = 0, freq = 0; i < devfreq->max_state; i++, freq++) {
199 opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &freq, 0);
200 if (IS_ERR(opp)) {
201 devm_kfree(devfreq->dev.parent, devfreq->freq_table);
202 return PTR_ERR(opp);
203 }
204 dev_pm_opp_put(opp);
205 devfreq->freq_table[i] = freq;
206 }
207
208 return 0;
209}
210
211/**
212 * devfreq_update_status() - Update statistics of devfreq behavior
213 * @devfreq: the devfreq instance
214 * @freq: the update target frequency
215 */
216int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
217{
218 int lev, prev_lev, ret = 0;
219 u64 cur_time;
220
221 lockdep_assert_held(&devfreq->lock);
222 cur_time = get_jiffies_64();
223
224 /* Immediately exit if previous_freq is not initialized yet. */
225 if (!devfreq->previous_freq)
226 goto out;
227
228 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
229 if (prev_lev < 0) {
230 ret = prev_lev;
231 goto out;
232 }
233
234 devfreq->stats.time_in_state[prev_lev] +=
235 cur_time - devfreq->stats.last_update;
236
237 lev = devfreq_get_freq_level(devfreq, freq);
238 if (lev < 0) {
239 ret = lev;
240 goto out;
241 }
242
243 if (lev != prev_lev) {
244 devfreq->stats.trans_table[
245 (prev_lev * devfreq->max_state) + lev]++;
246 devfreq->stats.total_trans++;
247 }
248
249out:
250 devfreq->stats.last_update = cur_time;
251 return ret;
252}
253EXPORT_SYMBOL(devfreq_update_status);
254
255/**
256 * find_devfreq_governor() - find devfreq governor from name
257 * @name: name of the governor
258 *
259 * Search the list of devfreq governors and return the matched
260 * governor's pointer. devfreq_list_lock should be held by the caller.
261 */
262static struct devfreq_governor *find_devfreq_governor(const char *name)
263{
264 struct devfreq_governor *tmp_governor;
265
266 lockdep_assert_held(&devfreq_list_lock);
267
268 if (IS_ERR_OR_NULL(name)) {
269 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
270 return ERR_PTR(-EINVAL);
271 }
272
273 list_for_each_entry(tmp_governor, &devfreq_governor_list, node) {
274 if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN))
275 return tmp_governor;
276 }
277
278 return ERR_PTR(-ENODEV);
279}
280
281/**
282 * try_then_request_governor() - Try to find the governor and request the
283 * module if is not found.
284 * @name: name of the governor
285 *
286 * Search the list of devfreq governors and request the module and try again
287 * if is not found. This can happen when both drivers (the governor driver
288 * and the driver that call devfreq_add_device) are built as modules.
289 * devfreq_list_lock should be held by the caller. Returns the matched
290 * governor's pointer or an error pointer.
291 */
292static struct devfreq_governor *try_then_request_governor(const char *name)
293{
294 struct devfreq_governor *governor;
295 int err = 0;
296
297 lockdep_assert_held(&devfreq_list_lock);
298
299 if (IS_ERR_OR_NULL(name)) {
300 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);
301 return ERR_PTR(-EINVAL);
302 }
303
304 governor = find_devfreq_governor(name);
305 if (IS_ERR(governor)) {
306 mutex_unlock(&devfreq_list_lock);
307
308 if (!strncmp(name, DEVFREQ_GOV_SIMPLE_ONDEMAND,
309 DEVFREQ_NAME_LEN))
310 err = request_module("governor_%s", "simpleondemand");
311 else
312 err = request_module("governor_%s", name);
313 /* Restore previous state before return */
314 mutex_lock(&devfreq_list_lock);
315 if (err)
316 return (err < 0) ? ERR_PTR(err) : ERR_PTR(-EINVAL);
317
318 governor = find_devfreq_governor(name);
319 }
320
321 return governor;
322}
323
324static int devfreq_notify_transition(struct devfreq *devfreq,
325 struct devfreq_freqs *freqs, unsigned int state)
326{
327 if (!devfreq)
328 return -EINVAL;
329
330 switch (state) {
331 case DEVFREQ_PRECHANGE:
332 srcu_notifier_call_chain(&devfreq->transition_notifier_list,
333 DEVFREQ_PRECHANGE, freqs);
334 break;
335
336 case DEVFREQ_POSTCHANGE:
337 srcu_notifier_call_chain(&devfreq->transition_notifier_list,
338 DEVFREQ_POSTCHANGE, freqs);
339 break;
340 default:
341 return -EINVAL;
342 }
343
344 return 0;
345}
346
347static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq,
348 u32 flags)
349{
350 struct devfreq_freqs freqs;
351 unsigned long cur_freq;
352 int err = 0;
353
354 if (devfreq->profile->get_cur_freq)
355 devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
356 else
357 cur_freq = devfreq->previous_freq;
358
359 freqs.old = cur_freq;
360 freqs.new = new_freq;
361 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
362
363 err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);
364 if (err) {
365 freqs.new = cur_freq;
366 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
367 return err;
368 }
369
370 /*
371 * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE
372 * and DEVFREQ_POSTCHANGE because for showing the correct frequency
373 * change order of between devfreq device and passive devfreq device.
374 */
375 if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)
376 trace_devfreq_frequency(devfreq, new_freq, cur_freq);
377
378 freqs.new = new_freq;
379 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
380
381 if (devfreq_update_status(devfreq, new_freq))
382 dev_warn(&devfreq->dev,
383 "Couldn't update frequency transition information.\n");
384
385 devfreq->previous_freq = new_freq;
386
387 if (devfreq->suspend_freq)
388 devfreq->resume_freq = new_freq;
389
390 return err;
391}
392
393/**
394 * devfreq_update_target() - Reevaluate the device and configure frequency
395 * on the final stage.
396 * @devfreq: the devfreq instance.
397 * @freq: the new frequency of parent device. This argument
398 * is only used for devfreq device using passive governor.
399 *
400 * Note: Lock devfreq->lock before calling devfreq_update_target. This function
401 * should be only used by both update_devfreq() and devfreq governors.
402 */
403int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)
404{
405 unsigned long min_freq, max_freq;
406 int err = 0;
407 u32 flags = 0;
408
409 lockdep_assert_held(&devfreq->lock);
410
411 if (!devfreq->governor)
412 return -EINVAL;
413
414 /* Reevaluate the proper frequency */
415 err = devfreq->governor->get_target_freq(devfreq, &freq);
416 if (err)
417 return err;
418 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
419
420 if (freq < min_freq) {
421 freq = min_freq;
422 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
423 }
424 if (freq > max_freq) {
425 freq = max_freq;
426 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
427 }
428
429 return devfreq_set_target(devfreq, freq, flags);
430}
431EXPORT_SYMBOL(devfreq_update_target);
432
433/* Load monitoring helper functions for governors use */
434
435/**
436 * update_devfreq() - Reevaluate the device and configure frequency.
437 * @devfreq: the devfreq instance.
438 *
439 * Note: Lock devfreq->lock before calling update_devfreq
440 * This function is exported for governors.
441 */
442int update_devfreq(struct devfreq *devfreq)
443{
444 return devfreq_update_target(devfreq, 0L);
445}
446EXPORT_SYMBOL(update_devfreq);
447
448/**
449 * devfreq_monitor() - Periodically poll devfreq objects.
450 * @work: the work struct used to run devfreq_monitor periodically.
451 *
452 */
453static void devfreq_monitor(struct work_struct *work)
454{
455 int err;
456 struct devfreq *devfreq = container_of(work,
457 struct devfreq, work.work);
458
459 mutex_lock(&devfreq->lock);
460 err = update_devfreq(devfreq);
461 if (err)
462 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);
463
464 if (devfreq->stop_polling)
465 goto out;
466
467 queue_delayed_work(devfreq_wq, &devfreq->work,
468 msecs_to_jiffies(devfreq->profile->polling_ms));
469
470out:
471 mutex_unlock(&devfreq->lock);
472 trace_devfreq_monitor(devfreq);
473}
474
475/**
476 * devfreq_monitor_start() - Start load monitoring of devfreq instance
477 * @devfreq: the devfreq instance.
478 *
479 * Helper function for starting devfreq device load monitoring. By default,
480 * deferrable timer is used for load monitoring. But the users can change this
481 * behavior using the "timer" type in devfreq_dev_profile. This function will be
482 * called by devfreq governor in response to the DEVFREQ_GOV_START event
483 * generated while adding a device to the devfreq framework.
484 */
485void devfreq_monitor_start(struct devfreq *devfreq)
486{
487 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
488 return;
489
490 mutex_lock(&devfreq->lock);
491 if (delayed_work_pending(&devfreq->work))
492 goto out;
493
494 switch (devfreq->profile->timer) {
495 case DEVFREQ_TIMER_DEFERRABLE:
496 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);
497 break;
498 case DEVFREQ_TIMER_DELAYED:
499 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);
500 break;
501 default:
502 goto out;
503 }
504
505 if (devfreq->profile->polling_ms)
506 queue_delayed_work(devfreq_wq, &devfreq->work,
507 msecs_to_jiffies(devfreq->profile->polling_ms));
508
509out:
510 devfreq->stop_polling = false;
511 mutex_unlock(&devfreq->lock);
512}
513EXPORT_SYMBOL(devfreq_monitor_start);
514
515/**
516 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance
517 * @devfreq: the devfreq instance.
518 *
519 * Helper function to stop devfreq device load monitoring. Function
520 * to be called from governor in response to DEVFREQ_GOV_STOP
521 * event when device is removed from devfreq framework.
522 */
523void devfreq_monitor_stop(struct devfreq *devfreq)
524{
525 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
526 return;
527
528 mutex_lock(&devfreq->lock);
529 if (devfreq->stop_polling) {
530 mutex_unlock(&devfreq->lock);
531 return;
532 }
533
534 devfreq->stop_polling = true;
535 mutex_unlock(&devfreq->lock);
536 cancel_delayed_work_sync(&devfreq->work);
537}
538EXPORT_SYMBOL(devfreq_monitor_stop);
539
540/**
541 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance
542 * @devfreq: the devfreq instance.
543 *
544 * Helper function to suspend devfreq device load monitoring. Function
545 * to be called from governor in response to DEVFREQ_GOV_SUSPEND
546 * event or when polling interval is set to zero.
547 *
548 * Note: Though this function is same as devfreq_monitor_stop(),
549 * intentionally kept separate to provide hooks for collecting
550 * transition statistics.
551 */
552void devfreq_monitor_suspend(struct devfreq *devfreq)
553{
554 mutex_lock(&devfreq->lock);
555 if (devfreq->stop_polling) {
556 mutex_unlock(&devfreq->lock);
557 return;
558 }
559
560 devfreq_update_status(devfreq, devfreq->previous_freq);
561 devfreq->stop_polling = true;
562 mutex_unlock(&devfreq->lock);
563
564 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
565 return;
566
567 cancel_delayed_work_sync(&devfreq->work);
568}
569EXPORT_SYMBOL(devfreq_monitor_suspend);
570
571/**
572 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance
573 * @devfreq: the devfreq instance.
574 *
575 * Helper function to resume devfreq device load monitoring. Function
576 * to be called from governor in response to DEVFREQ_GOV_RESUME
577 * event or when polling interval is set to non-zero.
578 */
579void devfreq_monitor_resume(struct devfreq *devfreq)
580{
581 unsigned long freq;
582
583 mutex_lock(&devfreq->lock);
584
585 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
586 goto out_update;
587
588 if (!devfreq->stop_polling)
589 goto out;
590
591 if (!delayed_work_pending(&devfreq->work) &&
592 devfreq->profile->polling_ms)
593 queue_delayed_work(devfreq_wq, &devfreq->work,
594 msecs_to_jiffies(devfreq->profile->polling_ms));
595
596out_update:
597 devfreq->stats.last_update = get_jiffies_64();
598 devfreq->stop_polling = false;
599
600 if (devfreq->profile->get_cur_freq &&
601 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
602 devfreq->previous_freq = freq;
603
604out:
605 mutex_unlock(&devfreq->lock);
606}
607EXPORT_SYMBOL(devfreq_monitor_resume);
608
609/**
610 * devfreq_update_interval() - Update device devfreq monitoring interval
611 * @devfreq: the devfreq instance.
612 * @delay: new polling interval to be set.
613 *
614 * Helper function to set new load monitoring polling interval. Function
615 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event.
616 */
617void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay)
618{
619 unsigned int cur_delay = devfreq->profile->polling_ms;
620 unsigned int new_delay = *delay;
621
622 mutex_lock(&devfreq->lock);
623 devfreq->profile->polling_ms = new_delay;
624
625 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))
626 goto out;
627
628 if (devfreq->stop_polling)
629 goto out;
630
631 /* if new delay is zero, stop polling */
632 if (!new_delay) {
633 mutex_unlock(&devfreq->lock);
634 cancel_delayed_work_sync(&devfreq->work);
635 return;
636 }
637
638 /* if current delay is zero, start polling with new delay */
639 if (!cur_delay) {
640 queue_delayed_work(devfreq_wq, &devfreq->work,
641 msecs_to_jiffies(devfreq->profile->polling_ms));
642 goto out;
643 }
644
645 /* if current delay is greater than new delay, restart polling */
646 if (cur_delay > new_delay) {
647 mutex_unlock(&devfreq->lock);
648 cancel_delayed_work_sync(&devfreq->work);
649 mutex_lock(&devfreq->lock);
650 if (!devfreq->stop_polling)
651 queue_delayed_work(devfreq_wq, &devfreq->work,
652 msecs_to_jiffies(devfreq->profile->polling_ms));
653 }
654out:
655 mutex_unlock(&devfreq->lock);
656}
657EXPORT_SYMBOL(devfreq_update_interval);
658
659/**
660 * devfreq_notifier_call() - Notify that the device frequency requirements
661 * has been changed out of devfreq framework.
662 * @nb: the notifier_block (supposed to be devfreq->nb)
663 * @type: not used
664 * @devp: not used
665 *
666 * Called by a notifier that uses devfreq->nb.
667 */
668static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
669 void *devp)
670{
671 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
672 int err = -EINVAL;
673
674 mutex_lock(&devfreq->lock);
675
676 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
677 if (!devfreq->scaling_min_freq)
678 goto out;
679
680 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
681 if (!devfreq->scaling_max_freq) {
682 devfreq->scaling_max_freq = ULONG_MAX;
683 goto out;
684 }
685
686 err = update_devfreq(devfreq);
687
688out:
689 mutex_unlock(&devfreq->lock);
690 if (err)
691 dev_err(devfreq->dev.parent,
692 "failed to update frequency from OPP notifier (%d)\n",
693 err);
694
695 return NOTIFY_OK;
696}
697
698/**
699 * qos_notifier_call() - Common handler for QoS constraints.
700 * @devfreq: the devfreq instance.
701 */
702static int qos_notifier_call(struct devfreq *devfreq)
703{
704 int err;
705
706 mutex_lock(&devfreq->lock);
707 err = update_devfreq(devfreq);
708 mutex_unlock(&devfreq->lock);
709 if (err)
710 dev_err(devfreq->dev.parent,
711 "failed to update frequency from PM QoS (%d)\n",
712 err);
713
714 return NOTIFY_OK;
715}
716
717/**
718 * qos_min_notifier_call() - Callback for QoS min_freq changes.
719 * @nb: Should be devfreq->nb_min
720 * @val: not used
721 * @ptr: not used
722 */
723static int qos_min_notifier_call(struct notifier_block *nb,
724 unsigned long val, void *ptr)
725{
726 return qos_notifier_call(container_of(nb, struct devfreq, nb_min));
727}
728
729/**
730 * qos_max_notifier_call() - Callback for QoS max_freq changes.
731 * @nb: Should be devfreq->nb_max
732 * @val: not used
733 * @ptr: not used
734 */
735static int qos_max_notifier_call(struct notifier_block *nb,
736 unsigned long val, void *ptr)
737{
738 return qos_notifier_call(container_of(nb, struct devfreq, nb_max));
739}
740
741/**
742 * devfreq_dev_release() - Callback for struct device to release the device.
743 * @dev: the devfreq device
744 *
745 * Remove devfreq from the list and release its resources.
746 */
747static void devfreq_dev_release(struct device *dev)
748{
749 struct devfreq *devfreq = to_devfreq(dev);
750 int err;
751
752 mutex_lock(&devfreq_list_lock);
753 list_del(&devfreq->node);
754 mutex_unlock(&devfreq_list_lock);
755
756 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,
757 DEV_PM_QOS_MAX_FREQUENCY);
758 if (err && err != -ENOENT)
759 dev_warn(dev->parent,
760 "Failed to remove max_freq notifier: %d\n", err);
761 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,
762 DEV_PM_QOS_MIN_FREQUENCY);
763 if (err && err != -ENOENT)
764 dev_warn(dev->parent,
765 "Failed to remove min_freq notifier: %d\n", err);
766
767 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {
768 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);
769 if (err < 0)
770 dev_warn(dev->parent,
771 "Failed to remove max_freq request: %d\n", err);
772 }
773 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {
774 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);
775 if (err < 0)
776 dev_warn(dev->parent,
777 "Failed to remove min_freq request: %d\n", err);
778 }
779
780 if (devfreq->profile->exit)
781 devfreq->profile->exit(devfreq->dev.parent);
782
783 if (devfreq->opp_table)
784 dev_pm_opp_put_opp_table(devfreq->opp_table);
785
786 mutex_destroy(&devfreq->lock);
787 srcu_cleanup_notifier_head(&devfreq->transition_notifier_list);
788 kfree(devfreq);
789}
790
791static void create_sysfs_files(struct devfreq *devfreq,
792 const struct devfreq_governor *gov);
793static void remove_sysfs_files(struct devfreq *devfreq,
794 const struct devfreq_governor *gov);
795
796/**
797 * devfreq_add_device() - Add devfreq feature to the device
798 * @dev: the device to add devfreq feature.
799 * @profile: device-specific profile to run devfreq.
800 * @governor_name: name of the policy to choose frequency.
801 * @data: devfreq driver pass to governors, governor should not change it.
802 */
803struct devfreq *devfreq_add_device(struct device *dev,
804 struct devfreq_dev_profile *profile,
805 const char *governor_name,
806 void *data)
807{
808 struct devfreq *devfreq;
809 struct devfreq_governor *governor;
810 unsigned long min_freq, max_freq;
811 int err = 0;
812
813 if (!dev || !profile || !governor_name) {
814 dev_err(dev, "%s: Invalid parameters.\n", __func__);
815 return ERR_PTR(-EINVAL);
816 }
817
818 mutex_lock(&devfreq_list_lock);
819 devfreq = find_device_devfreq(dev);
820 mutex_unlock(&devfreq_list_lock);
821 if (!IS_ERR(devfreq)) {
822 dev_err(dev, "%s: devfreq device already exists!\n",
823 __func__);
824 err = -EINVAL;
825 goto err_out;
826 }
827
828 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);
829 if (!devfreq) {
830 err = -ENOMEM;
831 goto err_out;
832 }
833
834 mutex_init(&devfreq->lock);
835 mutex_lock(&devfreq->lock);
836 devfreq->dev.parent = dev;
837 devfreq->dev.class = devfreq_class;
838 devfreq->dev.release = devfreq_dev_release;
839 INIT_LIST_HEAD(&devfreq->node);
840 devfreq->profile = profile;
841 devfreq->previous_freq = profile->initial_freq;
842 devfreq->last_status.current_frequency = profile->initial_freq;
843 devfreq->data = data;
844 devfreq->nb.notifier_call = devfreq_notifier_call;
845
846 if (devfreq->profile->timer < 0
847 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) {
848 mutex_unlock(&devfreq->lock);
849 err = -EINVAL;
850 goto err_dev;
851 }
852
853 if (!devfreq->profile->max_state || !devfreq->profile->freq_table) {
854 mutex_unlock(&devfreq->lock);
855 err = set_freq_table(devfreq);
856 if (err < 0)
857 goto err_dev;
858 mutex_lock(&devfreq->lock);
859 } else {
860 devfreq->freq_table = devfreq->profile->freq_table;
861 devfreq->max_state = devfreq->profile->max_state;
862 }
863
864 devfreq->scaling_min_freq = find_available_min_freq(devfreq);
865 if (!devfreq->scaling_min_freq) {
866 mutex_unlock(&devfreq->lock);
867 err = -EINVAL;
868 goto err_dev;
869 }
870
871 devfreq->scaling_max_freq = find_available_max_freq(devfreq);
872 if (!devfreq->scaling_max_freq) {
873 mutex_unlock(&devfreq->lock);
874 err = -EINVAL;
875 goto err_dev;
876 }
877
878 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
879
880 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);
881 devfreq->opp_table = dev_pm_opp_get_opp_table(dev);
882 if (IS_ERR(devfreq->opp_table))
883 devfreq->opp_table = NULL;
884
885 atomic_set(&devfreq->suspend_count, 0);
886
887 dev_set_name(&devfreq->dev, "%s", dev_name(dev));
888 err = device_register(&devfreq->dev);
889 if (err) {
890 mutex_unlock(&devfreq->lock);
891 put_device(&devfreq->dev);
892 goto err_out;
893 }
894
895 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,
896 array3_size(sizeof(unsigned int),
897 devfreq->max_state,
898 devfreq->max_state),
899 GFP_KERNEL);
900 if (!devfreq->stats.trans_table) {
901 mutex_unlock(&devfreq->lock);
902 err = -ENOMEM;
903 goto err_devfreq;
904 }
905
906 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,
907 devfreq->max_state,
908 sizeof(*devfreq->stats.time_in_state),
909 GFP_KERNEL);
910 if (!devfreq->stats.time_in_state) {
911 mutex_unlock(&devfreq->lock);
912 err = -ENOMEM;
913 goto err_devfreq;
914 }
915
916 devfreq->stats.total_trans = 0;
917 devfreq->stats.last_update = get_jiffies_64();
918
919 srcu_init_notifier_head(&devfreq->transition_notifier_list);
920
921 mutex_unlock(&devfreq->lock);
922
923 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,
924 DEV_PM_QOS_MIN_FREQUENCY, 0);
925 if (err < 0)
926 goto err_devfreq;
927 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,
928 DEV_PM_QOS_MAX_FREQUENCY,
929 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
930 if (err < 0)
931 goto err_devfreq;
932
933 devfreq->nb_min.notifier_call = qos_min_notifier_call;
934 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min,
935 DEV_PM_QOS_MIN_FREQUENCY);
936 if (err)
937 goto err_devfreq;
938
939 devfreq->nb_max.notifier_call = qos_max_notifier_call;
940 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max,
941 DEV_PM_QOS_MAX_FREQUENCY);
942 if (err)
943 goto err_devfreq;
944
945 mutex_lock(&devfreq_list_lock);
946
947 governor = try_then_request_governor(governor_name);
948 if (IS_ERR(governor)) {
949 dev_err(dev, "%s: Unable to find governor for the device\n",
950 __func__);
951 err = PTR_ERR(governor);
952 goto err_init;
953 }
954
955 devfreq->governor = governor;
956 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,
957 NULL);
958 if (err) {
959 dev_err_probe(dev, err,
960 "%s: Unable to start governor for the device\n",
961 __func__);
962 goto err_init;
963 }
964 create_sysfs_files(devfreq, devfreq->governor);
965
966 list_add(&devfreq->node, &devfreq_list);
967
968 mutex_unlock(&devfreq_list_lock);
969
970 if (devfreq->profile->is_cooling_device) {
971 devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);
972 if (IS_ERR(devfreq->cdev))
973 devfreq->cdev = NULL;
974 }
975
976 return devfreq;
977
978err_init:
979 mutex_unlock(&devfreq_list_lock);
980err_devfreq:
981 devfreq_remove_device(devfreq);
982 devfreq = NULL;
983err_dev:
984 kfree(devfreq);
985err_out:
986 return ERR_PTR(err);
987}
988EXPORT_SYMBOL(devfreq_add_device);
989
990/**
991 * devfreq_remove_device() - Remove devfreq feature from a device.
992 * @devfreq: the devfreq instance to be removed
993 *
994 * The opposite of devfreq_add_device().
995 */
996int devfreq_remove_device(struct devfreq *devfreq)
997{
998 if (!devfreq)
999 return -EINVAL;
1000
1001 devfreq_cooling_unregister(devfreq->cdev);
1002
1003 if (devfreq->governor) {
1004 devfreq->governor->event_handler(devfreq,
1005 DEVFREQ_GOV_STOP, NULL);
1006 remove_sysfs_files(devfreq, devfreq->governor);
1007 }
1008
1009 device_unregister(&devfreq->dev);
1010
1011 return 0;
1012}
1013EXPORT_SYMBOL(devfreq_remove_device);
1014
1015static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)
1016{
1017 struct devfreq **r = res;
1018
1019 if (WARN_ON(!r || !*r))
1020 return 0;
1021
1022 return *r == data;
1023}
1024
1025static void devm_devfreq_dev_release(struct device *dev, void *res)
1026{
1027 devfreq_remove_device(*(struct devfreq **)res);
1028}
1029
1030/**
1031 * devm_devfreq_add_device() - Resource-managed devfreq_add_device()
1032 * @dev: the device to add devfreq feature.
1033 * @profile: device-specific profile to run devfreq.
1034 * @governor_name: name of the policy to choose frequency.
1035 * @data: devfreq driver pass to governors, governor should not change it.
1036 *
1037 * This function manages automatically the memory of devfreq device using device
1038 * resource management and simplify the free operation for memory of devfreq
1039 * device.
1040 */
1041struct devfreq *devm_devfreq_add_device(struct device *dev,
1042 struct devfreq_dev_profile *profile,
1043 const char *governor_name,
1044 void *data)
1045{
1046 struct devfreq **ptr, *devfreq;
1047
1048 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);
1049 if (!ptr)
1050 return ERR_PTR(-ENOMEM);
1051
1052 devfreq = devfreq_add_device(dev, profile, governor_name, data);
1053 if (IS_ERR(devfreq)) {
1054 devres_free(ptr);
1055 return devfreq;
1056 }
1057
1058 *ptr = devfreq;
1059 devres_add(dev, ptr);
1060
1061 return devfreq;
1062}
1063EXPORT_SYMBOL(devm_devfreq_add_device);
1064
1065#ifdef CONFIG_OF
1066/*
1067 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree
1068 * @node - pointer to device_node
1069 *
1070 * return the instance of devfreq device
1071 */
1072struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1073{
1074 struct devfreq *devfreq;
1075
1076 if (!node)
1077 return ERR_PTR(-EINVAL);
1078
1079 mutex_lock(&devfreq_list_lock);
1080 list_for_each_entry(devfreq, &devfreq_list, node) {
1081 if (devfreq->dev.parent
1082 && device_match_of_node(devfreq->dev.parent, node)) {
1083 mutex_unlock(&devfreq_list_lock);
1084 return devfreq;
1085 }
1086 }
1087 mutex_unlock(&devfreq_list_lock);
1088
1089 return ERR_PTR(-ENODEV);
1090}
1091
1092/*
1093 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
1094 * @dev - instance to the given device
1095 * @phandle_name - name of property holding a phandle value
1096 * @index - index into list of devfreq
1097 *
1098 * return the instance of devfreq device
1099 */
1100struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1101 const char *phandle_name, int index)
1102{
1103 struct device_node *node;
1104 struct devfreq *devfreq;
1105
1106 if (!dev || !phandle_name)
1107 return ERR_PTR(-EINVAL);
1108
1109 if (!dev->of_node)
1110 return ERR_PTR(-EINVAL);
1111
1112 node = of_parse_phandle(dev->of_node, phandle_name, index);
1113 if (!node)
1114 return ERR_PTR(-ENODEV);
1115
1116 devfreq = devfreq_get_devfreq_by_node(node);
1117 of_node_put(node);
1118
1119 return devfreq;
1120}
1121
1122#else
1123struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1124{
1125 return ERR_PTR(-ENODEV);
1126}
1127
1128struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1129 const char *phandle_name, int index)
1130{
1131 return ERR_PTR(-ENODEV);
1132}
1133#endif /* CONFIG_OF */
1134EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
1135EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
1136
1137/**
1138 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
1139 * @dev: the device from which to remove devfreq feature.
1140 * @devfreq: the devfreq instance to be removed
1141 */
1142void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
1143{
1144 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
1145 devm_devfreq_dev_match, devfreq));
1146}
1147EXPORT_SYMBOL(devm_devfreq_remove_device);
1148
1149/**
1150 * devfreq_suspend_device() - Suspend devfreq of a device.
1151 * @devfreq: the devfreq instance to be suspended
1152 *
1153 * This function is intended to be called by the pm callbacks
1154 * (e.g., runtime_suspend, suspend) of the device driver that
1155 * holds the devfreq.
1156 */
1157int devfreq_suspend_device(struct devfreq *devfreq)
1158{
1159 int ret;
1160
1161 if (!devfreq)
1162 return -EINVAL;
1163
1164 if (atomic_inc_return(&devfreq->suspend_count) > 1)
1165 return 0;
1166
1167 if (devfreq->governor) {
1168 ret = devfreq->governor->event_handler(devfreq,
1169 DEVFREQ_GOV_SUSPEND, NULL);
1170 if (ret)
1171 return ret;
1172 }
1173
1174 if (devfreq->suspend_freq) {
1175 mutex_lock(&devfreq->lock);
1176 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
1177 mutex_unlock(&devfreq->lock);
1178 if (ret)
1179 return ret;
1180 }
1181
1182 return 0;
1183}
1184EXPORT_SYMBOL(devfreq_suspend_device);
1185
1186/**
1187 * devfreq_resume_device() - Resume devfreq of a device.
1188 * @devfreq: the devfreq instance to be resumed
1189 *
1190 * This function is intended to be called by the pm callbacks
1191 * (e.g., runtime_resume, resume) of the device driver that
1192 * holds the devfreq.
1193 */
1194int devfreq_resume_device(struct devfreq *devfreq)
1195{
1196 int ret;
1197
1198 if (!devfreq)
1199 return -EINVAL;
1200
1201 if (atomic_dec_return(&devfreq->suspend_count) >= 1)
1202 return 0;
1203
1204 if (devfreq->resume_freq) {
1205 mutex_lock(&devfreq->lock);
1206 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
1207 mutex_unlock(&devfreq->lock);
1208 if (ret)
1209 return ret;
1210 }
1211
1212 if (devfreq->governor) {
1213 ret = devfreq->governor->event_handler(devfreq,
1214 DEVFREQ_GOV_RESUME, NULL);
1215 if (ret)
1216 return ret;
1217 }
1218
1219 return 0;
1220}
1221EXPORT_SYMBOL(devfreq_resume_device);
1222
1223/**
1224 * devfreq_suspend() - Suspend devfreq governors and devices
1225 *
1226 * Called during system wide Suspend/Hibernate cycles for suspending governors
1227 * and devices preserving the state for resume. On some platforms the devfreq
1228 * device must have precise state (frequency) after resume in order to provide
1229 * fully operating setup.
1230 */
1231void devfreq_suspend(void)
1232{
1233 struct devfreq *devfreq;
1234 int ret;
1235
1236 mutex_lock(&devfreq_list_lock);
1237 list_for_each_entry(devfreq, &devfreq_list, node) {
1238 ret = devfreq_suspend_device(devfreq);
1239 if (ret)
1240 dev_err(&devfreq->dev,
1241 "failed to suspend devfreq device\n");
1242 }
1243 mutex_unlock(&devfreq_list_lock);
1244}
1245
1246/**
1247 * devfreq_resume() - Resume devfreq governors and devices
1248 *
1249 * Called during system wide Suspend/Hibernate cycle for resuming governors and
1250 * devices that are suspended with devfreq_suspend().
1251 */
1252void devfreq_resume(void)
1253{
1254 struct devfreq *devfreq;
1255 int ret;
1256
1257 mutex_lock(&devfreq_list_lock);
1258 list_for_each_entry(devfreq, &devfreq_list, node) {
1259 ret = devfreq_resume_device(devfreq);
1260 if (ret)
1261 dev_warn(&devfreq->dev,
1262 "failed to resume devfreq device\n");
1263 }
1264 mutex_unlock(&devfreq_list_lock);
1265}
1266
1267/**
1268 * devfreq_add_governor() - Add devfreq governor
1269 * @governor: the devfreq governor to be added
1270 */
1271int devfreq_add_governor(struct devfreq_governor *governor)
1272{
1273 struct devfreq_governor *g;
1274 struct devfreq *devfreq;
1275 int err = 0;
1276
1277 if (!governor) {
1278 pr_err("%s: Invalid parameters.\n", __func__);
1279 return -EINVAL;
1280 }
1281
1282 mutex_lock(&devfreq_list_lock);
1283 g = find_devfreq_governor(governor->name);
1284 if (!IS_ERR(g)) {
1285 pr_err("%s: governor %s already registered\n", __func__,
1286 g->name);
1287 err = -EINVAL;
1288 goto err_out;
1289 }
1290
1291 list_add(&governor->node, &devfreq_governor_list);
1292
1293 list_for_each_entry(devfreq, &devfreq_list, node) {
1294 int ret = 0;
1295 struct device *dev = devfreq->dev.parent;
1296
1297 if (!strncmp(devfreq->governor->name, governor->name,
1298 DEVFREQ_NAME_LEN)) {
1299 /* The following should never occur */
1300 if (devfreq->governor) {
1301 dev_warn(dev,
1302 "%s: Governor %s already present\n",
1303 __func__, devfreq->governor->name);
1304 ret = devfreq->governor->event_handler(devfreq,
1305 DEVFREQ_GOV_STOP, NULL);
1306 if (ret) {
1307 dev_warn(dev,
1308 "%s: Governor %s stop = %d\n",
1309 __func__,
1310 devfreq->governor->name, ret);
1311 }
1312 /* Fall through */
1313 }
1314 devfreq->governor = governor;
1315 ret = devfreq->governor->event_handler(devfreq,
1316 DEVFREQ_GOV_START, NULL);
1317 if (ret) {
1318 dev_warn(dev, "%s: Governor %s start=%d\n",
1319 __func__, devfreq->governor->name,
1320 ret);
1321 }
1322 }
1323 }
1324
1325err_out:
1326 mutex_unlock(&devfreq_list_lock);
1327
1328 return err;
1329}
1330EXPORT_SYMBOL(devfreq_add_governor);
1331
1332static void devm_devfreq_remove_governor(void *governor)
1333{
1334 WARN_ON(devfreq_remove_governor(governor));
1335}
1336
1337/**
1338 * devm_devfreq_add_governor() - Add devfreq governor
1339 * @dev: device which adds devfreq governor
1340 * @governor: the devfreq governor to be added
1341 *
1342 * This is a resource-managed variant of devfreq_add_governor().
1343 */
1344int devm_devfreq_add_governor(struct device *dev,
1345 struct devfreq_governor *governor)
1346{
1347 int err;
1348
1349 err = devfreq_add_governor(governor);
1350 if (err)
1351 return err;
1352
1353 return devm_add_action_or_reset(dev, devm_devfreq_remove_governor,
1354 governor);
1355}
1356EXPORT_SYMBOL(devm_devfreq_add_governor);
1357
1358/**
1359 * devfreq_remove_governor() - Remove devfreq feature from a device.
1360 * @governor: the devfreq governor to be removed
1361 */
1362int devfreq_remove_governor(struct devfreq_governor *governor)
1363{
1364 struct devfreq_governor *g;
1365 struct devfreq *devfreq;
1366 int err = 0;
1367
1368 if (!governor) {
1369 pr_err("%s: Invalid parameters.\n", __func__);
1370 return -EINVAL;
1371 }
1372
1373 mutex_lock(&devfreq_list_lock);
1374 g = find_devfreq_governor(governor->name);
1375 if (IS_ERR(g)) {
1376 pr_err("%s: governor %s not registered\n", __func__,
1377 governor->name);
1378 err = PTR_ERR(g);
1379 goto err_out;
1380 }
1381 list_for_each_entry(devfreq, &devfreq_list, node) {
1382 int ret;
1383 struct device *dev = devfreq->dev.parent;
1384
1385 if (!strncmp(devfreq->governor->name, governor->name,
1386 DEVFREQ_NAME_LEN)) {
1387 /* we should have a devfreq governor! */
1388 if (!devfreq->governor) {
1389 dev_warn(dev, "%s: Governor %s NOT present\n",
1390 __func__, governor->name);
1391 continue;
1392 /* Fall through */
1393 }
1394 ret = devfreq->governor->event_handler(devfreq,
1395 DEVFREQ_GOV_STOP, NULL);
1396 if (ret) {
1397 dev_warn(dev, "%s: Governor %s stop=%d\n",
1398 __func__, devfreq->governor->name,
1399 ret);
1400 }
1401 devfreq->governor = NULL;
1402 }
1403 }
1404
1405 list_del(&governor->node);
1406err_out:
1407 mutex_unlock(&devfreq_list_lock);
1408
1409 return err;
1410}
1411EXPORT_SYMBOL(devfreq_remove_governor);
1412
1413static ssize_t name_show(struct device *dev,
1414 struct device_attribute *attr, char *buf)
1415{
1416 struct devfreq *df = to_devfreq(dev);
1417 return sprintf(buf, "%s\n", dev_name(df->dev.parent));
1418}
1419static DEVICE_ATTR_RO(name);
1420
1421static ssize_t governor_show(struct device *dev,
1422 struct device_attribute *attr, char *buf)
1423{
1424 struct devfreq *df = to_devfreq(dev);
1425
1426 if (!df->governor)
1427 return -EINVAL;
1428
1429 return sprintf(buf, "%s\n", df->governor->name);
1430}
1431
1432static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
1433 const char *buf, size_t count)
1434{
1435 struct devfreq *df = to_devfreq(dev);
1436 int ret;
1437 char str_governor[DEVFREQ_NAME_LEN + 1];
1438 const struct devfreq_governor *governor, *prev_governor;
1439
1440 if (!df->governor)
1441 return -EINVAL;
1442
1443 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
1444 if (ret != 1)
1445 return -EINVAL;
1446
1447 mutex_lock(&devfreq_list_lock);
1448 governor = try_then_request_governor(str_governor);
1449 if (IS_ERR(governor)) {
1450 ret = PTR_ERR(governor);
1451 goto out;
1452 }
1453 if (df->governor == governor) {
1454 ret = 0;
1455 goto out;
1456 } else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)
1457 || IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {
1458 ret = -EINVAL;
1459 goto out;
1460 }
1461
1462 /*
1463 * Stop the current governor and remove the specific sysfs files
1464 * which depend on current governor.
1465 */
1466 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1467 if (ret) {
1468 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1469 __func__, df->governor->name, ret);
1470 goto out;
1471 }
1472 remove_sysfs_files(df, df->governor);
1473
1474 /*
1475 * Start the new governor and create the specific sysfs files
1476 * which depend on the new governor.
1477 */
1478 prev_governor = df->governor;
1479 df->governor = governor;
1480 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1481 if (ret) {
1482 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1483 __func__, df->governor->name, ret);
1484
1485 /* Restore previous governor */
1486 df->governor = prev_governor;
1487 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1488 if (ret) {
1489 dev_err(dev,
1490 "%s: reverting to Governor %s failed (%d)\n",
1491 __func__, prev_governor->name, ret);
1492 df->governor = NULL;
1493 goto out;
1494 }
1495 }
1496
1497 /*
1498 * Create the sysfs files for the new governor. But if failed to start
1499 * the new governor, restore the sysfs files of previous governor.
1500 */
1501 create_sysfs_files(df, df->governor);
1502
1503out:
1504 mutex_unlock(&devfreq_list_lock);
1505
1506 if (!ret)
1507 ret = count;
1508 return ret;
1509}
1510static DEVICE_ATTR_RW(governor);
1511
1512static ssize_t available_governors_show(struct device *d,
1513 struct device_attribute *attr,
1514 char *buf)
1515{
1516 struct devfreq *df = to_devfreq(d);
1517 ssize_t count = 0;
1518
1519 if (!df->governor)
1520 return -EINVAL;
1521
1522 mutex_lock(&devfreq_list_lock);
1523
1524 /*
1525 * The devfreq with immutable governor (e.g., passive) shows
1526 * only own governor.
1527 */
1528 if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {
1529 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
1530 "%s ", df->governor->name);
1531 /*
1532 * The devfreq device shows the registered governor except for
1533 * immutable governors such as passive governor .
1534 */
1535 } else {
1536 struct devfreq_governor *governor;
1537
1538 list_for_each_entry(governor, &devfreq_governor_list, node) {
1539 if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))
1540 continue;
1541 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1542 "%s ", governor->name);
1543 }
1544 }
1545
1546 mutex_unlock(&devfreq_list_lock);
1547
1548 /* Truncate the trailing space */
1549 if (count)
1550 count--;
1551
1552 count += sprintf(&buf[count], "\n");
1553
1554 return count;
1555}
1556static DEVICE_ATTR_RO(available_governors);
1557
1558static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
1559 char *buf)
1560{
1561 unsigned long freq;
1562 struct devfreq *df = to_devfreq(dev);
1563
1564 if (!df->profile)
1565 return -EINVAL;
1566
1567 if (df->profile->get_cur_freq &&
1568 !df->profile->get_cur_freq(df->dev.parent, &freq))
1569 return sprintf(buf, "%lu\n", freq);
1570
1571 return sprintf(buf, "%lu\n", df->previous_freq);
1572}
1573static DEVICE_ATTR_RO(cur_freq);
1574
1575static ssize_t target_freq_show(struct device *dev,
1576 struct device_attribute *attr, char *buf)
1577{
1578 struct devfreq *df = to_devfreq(dev);
1579
1580 return sprintf(buf, "%lu\n", df->previous_freq);
1581}
1582static DEVICE_ATTR_RO(target_freq);
1583
1584static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
1585 const char *buf, size_t count)
1586{
1587 struct devfreq *df = to_devfreq(dev);
1588 unsigned long value;
1589 int ret;
1590
1591 /*
1592 * Protect against theoretical sysfs writes between
1593 * device_add and dev_pm_qos_add_request
1594 */
1595 if (!dev_pm_qos_request_active(&df->user_min_freq_req))
1596 return -EAGAIN;
1597
1598 ret = sscanf(buf, "%lu", &value);
1599 if (ret != 1)
1600 return -EINVAL;
1601
1602 /* Round down to kHz for PM QoS */
1603 ret = dev_pm_qos_update_request(&df->user_min_freq_req,
1604 value / HZ_PER_KHZ);
1605 if (ret < 0)
1606 return ret;
1607
1608 return count;
1609}
1610
1611static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
1612 char *buf)
1613{
1614 struct devfreq *df = to_devfreq(dev);
1615 unsigned long min_freq, max_freq;
1616
1617 mutex_lock(&df->lock);
1618 devfreq_get_freq_range(df, &min_freq, &max_freq);
1619 mutex_unlock(&df->lock);
1620
1621 return sprintf(buf, "%lu\n", min_freq);
1622}
1623static DEVICE_ATTR_RW(min_freq);
1624
1625static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
1626 const char *buf, size_t count)
1627{
1628 struct devfreq *df = to_devfreq(dev);
1629 unsigned long value;
1630 int ret;
1631
1632 /*
1633 * Protect against theoretical sysfs writes between
1634 * device_add and dev_pm_qos_add_request
1635 */
1636 if (!dev_pm_qos_request_active(&df->user_max_freq_req))
1637 return -EINVAL;
1638
1639 ret = sscanf(buf, "%lu", &value);
1640 if (ret != 1)
1641 return -EINVAL;
1642
1643 /*
1644 * PM QoS frequencies are in kHz so we need to convert. Convert by
1645 * rounding upwards so that the acceptable interval never shrinks.
1646 *
1647 * For example if the user writes "666666666" to sysfs this value will
1648 * be converted to 666667 kHz and back to 666667000 Hz before an OPP
1649 * lookup, this ensures that an OPP of 666666666Hz is still accepted.
1650 *
1651 * A value of zero means "no limit".
1652 */
1653 if (value)
1654 value = DIV_ROUND_UP(value, HZ_PER_KHZ);
1655 else
1656 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
1657
1658 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
1659 if (ret < 0)
1660 return ret;
1661
1662 return count;
1663}
1664
1665static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
1666 char *buf)
1667{
1668 struct devfreq *df = to_devfreq(dev);
1669 unsigned long min_freq, max_freq;
1670
1671 mutex_lock(&df->lock);
1672 devfreq_get_freq_range(df, &min_freq, &max_freq);
1673 mutex_unlock(&df->lock);
1674
1675 return sprintf(buf, "%lu\n", max_freq);
1676}
1677static DEVICE_ATTR_RW(max_freq);
1678
1679static ssize_t available_frequencies_show(struct device *d,
1680 struct device_attribute *attr,
1681 char *buf)
1682{
1683 struct devfreq *df = to_devfreq(d);
1684 ssize_t count = 0;
1685 int i;
1686
1687 if (!df->profile)
1688 return -EINVAL;
1689
1690 mutex_lock(&df->lock);
1691
1692 for (i = 0; i < df->max_state; i++)
1693 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1694 "%lu ", df->freq_table[i]);
1695
1696 mutex_unlock(&df->lock);
1697 /* Truncate the trailing space */
1698 if (count)
1699 count--;
1700
1701 count += sprintf(&buf[count], "\n");
1702
1703 return count;
1704}
1705static DEVICE_ATTR_RO(available_frequencies);
1706
1707static ssize_t trans_stat_show(struct device *dev,
1708 struct device_attribute *attr, char *buf)
1709{
1710 struct devfreq *df = to_devfreq(dev);
1711 ssize_t len = 0;
1712 int i, j;
1713 unsigned int max_state;
1714
1715 if (!df->profile)
1716 return -EINVAL;
1717 max_state = df->max_state;
1718
1719 if (max_state == 0)
1720 return sysfs_emit(buf, "Not Supported.\n");
1721
1722 mutex_lock(&df->lock);
1723 if (!df->stop_polling &&
1724 devfreq_update_status(df, df->previous_freq)) {
1725 mutex_unlock(&df->lock);
1726 return 0;
1727 }
1728 mutex_unlock(&df->lock);
1729
1730 len += sysfs_emit_at(buf, len, " From : To\n");
1731 len += sysfs_emit_at(buf, len, " :");
1732 for (i = 0; i < max_state; i++) {
1733 if (len >= PAGE_SIZE - 1)
1734 break;
1735 len += sysfs_emit_at(buf, len, "%10lu",
1736 df->freq_table[i]);
1737 }
1738
1739 if (len >= PAGE_SIZE - 1)
1740 return PAGE_SIZE - 1;
1741 len += sysfs_emit_at(buf, len, " time(ms)\n");
1742
1743 for (i = 0; i < max_state; i++) {
1744 if (len >= PAGE_SIZE - 1)
1745 break;
1746 if (df->freq_table[2] == df->previous_freq)
1747 len += sysfs_emit_at(buf, len, "*");
1748 else
1749 len += sysfs_emit_at(buf, len, " ");
1750 if (len >= PAGE_SIZE - 1)
1751 break;
1752 len += sysfs_emit_at(buf, len, "%10lu:", df->freq_table[i]);
1753 for (j = 0; j < max_state; j++) {
1754 if (len >= PAGE_SIZE - 1)
1755 break;
1756 len += sysfs_emit_at(buf, len, "%10u",
1757 df->stats.trans_table[(i * max_state) + j]);
1758 }
1759 if (len >= PAGE_SIZE - 1)
1760 break;
1761 len += sysfs_emit_at(buf, len, "%10llu\n", (u64)
1762 jiffies64_to_msecs(df->stats.time_in_state[i]));
1763 }
1764
1765 if (len < PAGE_SIZE - 1)
1766 len += sysfs_emit_at(buf, len, "Total transition : %u\n",
1767 df->stats.total_trans);
1768 if (len >= PAGE_SIZE - 1) {
1769 pr_warn_once("devfreq transition table exceeds PAGE_SIZE. Disabling\n");
1770 return -EFBIG;
1771 }
1772
1773 return len;
1774}
1775
1776static ssize_t trans_stat_store(struct device *dev,
1777 struct device_attribute *attr,
1778 const char *buf, size_t count)
1779{
1780 struct devfreq *df = to_devfreq(dev);
1781 int err, value;
1782
1783 if (!df->profile)
1784 return -EINVAL;
1785
1786 if (df->max_state == 0)
1787 return count;
1788
1789 err = kstrtoint(buf, 10, &value);
1790 if (err || value != 0)
1791 return -EINVAL;
1792
1793 mutex_lock(&df->lock);
1794 memset(df->stats.time_in_state, 0, (df->max_state *
1795 sizeof(*df->stats.time_in_state)));
1796 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
1797 df->max_state,
1798 df->max_state));
1799 df->stats.total_trans = 0;
1800 df->stats.last_update = get_jiffies_64();
1801 mutex_unlock(&df->lock);
1802
1803 return count;
1804}
1805static DEVICE_ATTR_RW(trans_stat);
1806
1807static struct attribute *devfreq_attrs[] = {
1808 &dev_attr_name.attr,
1809 &dev_attr_governor.attr,
1810 &dev_attr_available_governors.attr,
1811 &dev_attr_cur_freq.attr,
1812 &dev_attr_available_frequencies.attr,
1813 &dev_attr_target_freq.attr,
1814 &dev_attr_min_freq.attr,
1815 &dev_attr_max_freq.attr,
1816 &dev_attr_trans_stat.attr,
1817 NULL,
1818};
1819ATTRIBUTE_GROUPS(devfreq);
1820
1821static ssize_t polling_interval_show(struct device *dev,
1822 struct device_attribute *attr, char *buf)
1823{
1824 struct devfreq *df = to_devfreq(dev);
1825
1826 if (!df->profile)
1827 return -EINVAL;
1828
1829 return sprintf(buf, "%d\n", df->profile->polling_ms);
1830}
1831
1832static ssize_t polling_interval_store(struct device *dev,
1833 struct device_attribute *attr,
1834 const char *buf, size_t count)
1835{
1836 struct devfreq *df = to_devfreq(dev);
1837 unsigned int value;
1838 int ret;
1839
1840 if (!df->governor)
1841 return -EINVAL;
1842
1843 ret = sscanf(buf, "%u", &value);
1844 if (ret != 1)
1845 return -EINVAL;
1846
1847 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
1848 ret = count;
1849
1850 return ret;
1851}
1852static DEVICE_ATTR_RW(polling_interval);
1853
1854static ssize_t timer_show(struct device *dev,
1855 struct device_attribute *attr, char *buf)
1856{
1857 struct devfreq *df = to_devfreq(dev);
1858
1859 if (!df->profile)
1860 return -EINVAL;
1861
1862 return sprintf(buf, "%s\n", timer_name[df->profile->timer]);
1863}
1864
1865static ssize_t timer_store(struct device *dev, struct device_attribute *attr,
1866 const char *buf, size_t count)
1867{
1868 struct devfreq *df = to_devfreq(dev);
1869 char str_timer[DEVFREQ_NAME_LEN + 1];
1870 int timer = -1;
1871 int ret = 0, i;
1872
1873 if (!df->governor || !df->profile)
1874 return -EINVAL;
1875
1876 ret = sscanf(buf, "%16s", str_timer);
1877 if (ret != 1)
1878 return -EINVAL;
1879
1880 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {
1881 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {
1882 timer = i;
1883 break;
1884 }
1885 }
1886
1887 if (timer < 0) {
1888 ret = -EINVAL;
1889 goto out;
1890 }
1891
1892 if (df->profile->timer == timer) {
1893 ret = 0;
1894 goto out;
1895 }
1896
1897 mutex_lock(&df->lock);
1898 df->profile->timer = timer;
1899 mutex_unlock(&df->lock);
1900
1901 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1902 if (ret) {
1903 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1904 __func__, df->governor->name, ret);
1905 goto out;
1906 }
1907
1908 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1909 if (ret)
1910 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1911 __func__, df->governor->name, ret);
1912out:
1913 return ret ? ret : count;
1914}
1915static DEVICE_ATTR_RW(timer);
1916
1917#define CREATE_SYSFS_FILE(df, name) \
1918{ \
1919 int ret; \
1920 ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \
1921 if (ret < 0) { \
1922 dev_warn(&df->dev, \
1923 "Unable to create attr(%s)\n", "##name"); \
1924 } \
1925} \
1926
1927/* Create the specific sysfs files which depend on each governor. */
1928static void create_sysfs_files(struct devfreq *devfreq,
1929 const struct devfreq_governor *gov)
1930{
1931 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
1932 CREATE_SYSFS_FILE(devfreq, polling_interval);
1933 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
1934 CREATE_SYSFS_FILE(devfreq, timer);
1935}
1936
1937/* Remove the specific sysfs files which depend on each governor. */
1938static void remove_sysfs_files(struct devfreq *devfreq,
1939 const struct devfreq_governor *gov)
1940{
1941 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))
1942 sysfs_remove_file(&devfreq->dev.kobj,
1943 &dev_attr_polling_interval.attr);
1944 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))
1945 sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr);
1946}
1947
1948/**
1949 * devfreq_summary_show() - Show the summary of the devfreq devices
1950 * @s: seq_file instance to show the summary of devfreq devices
1951 * @data: not used
1952 *
1953 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
1954 * It helps that user can know the detailed information of the devfreq devices.
1955 *
1956 * Return 0 always because it shows the information without any data change.
1957 */
1958static int devfreq_summary_show(struct seq_file *s, void *data)
1959{
1960 struct devfreq *devfreq;
1961 struct devfreq *p_devfreq = NULL;
1962 unsigned long cur_freq, min_freq, max_freq;
1963 unsigned int polling_ms;
1964 unsigned int timer;
1965
1966 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
1967 "dev",
1968 "parent_dev",
1969 "governor",
1970 "timer",
1971 "polling_ms",
1972 "cur_freq_Hz",
1973 "min_freq_Hz",
1974 "max_freq_Hz");
1975 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
1976 "------------------------------",
1977 "------------------------------",
1978 "---------------",
1979 "----------",
1980 "----------",
1981 "------------",
1982 "------------",
1983 "------------");
1984
1985 mutex_lock(&devfreq_list_lock);
1986
1987 list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
1988#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
1989 if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,
1990 DEVFREQ_NAME_LEN)) {
1991 struct devfreq_passive_data *data = devfreq->data;
1992
1993 if (data)
1994 p_devfreq = data->parent;
1995 } else {
1996 p_devfreq = NULL;
1997 }
1998#endif
1999
2000 mutex_lock(&devfreq->lock);
2001 cur_freq = devfreq->previous_freq;
2002 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);
2003 timer = devfreq->profile->timer;
2004
2005 if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))
2006 polling_ms = devfreq->profile->polling_ms;
2007 else
2008 polling_ms = 0;
2009 mutex_unlock(&devfreq->lock);
2010
2011 seq_printf(s,
2012 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
2013 dev_name(&devfreq->dev),
2014 p_devfreq ? dev_name(&p_devfreq->dev) : "null",
2015 devfreq->governor->name,
2016 polling_ms ? timer_name[timer] : "null",
2017 polling_ms,
2018 cur_freq,
2019 min_freq,
2020 max_freq);
2021 }
2022
2023 mutex_unlock(&devfreq_list_lock);
2024
2025 return 0;
2026}
2027DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
2028
2029static int __init devfreq_init(void)
2030{
2031 devfreq_class = class_create("devfreq");
2032 if (IS_ERR(devfreq_class)) {
2033 pr_err("%s: couldn't create class\n", __FILE__);
2034 return PTR_ERR(devfreq_class);
2035 }
2036
2037 devfreq_wq = create_freezable_workqueue("devfreq_wq");
2038 if (!devfreq_wq) {
2039 class_destroy(devfreq_class);
2040 pr_err("%s: couldn't create workqueue\n", __FILE__);
2041 return -ENOMEM;
2042 }
2043 devfreq_class->dev_groups = devfreq_groups;
2044
2045 devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
2046 debugfs_create_file("devfreq_summary", 0444,
2047 devfreq_debugfs, NULL,
2048 &devfreq_summary_fops);
2049
2050 return 0;
2051}
2052subsys_initcall(devfreq_init);
2053
2054/*
2055 * The following are helper functions for devfreq user device drivers with
2056 * OPP framework.
2057 */
2058
2059/**
2060 * devfreq_recommended_opp() - Helper function to get proper OPP for the
2061 * freq value given to target callback.
2062 * @dev: The devfreq user device. (parent of devfreq)
2063 * @freq: The frequency given to target function
2064 * @flags: Flags handed from devfreq framework.
2065 *
2066 * The callers are required to call dev_pm_opp_put() for the returned OPP after
2067 * use.
2068 */
2069struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
2070 unsigned long *freq,
2071 u32 flags)
2072{
2073 struct dev_pm_opp *opp;
2074
2075 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
2076 /* The freq is an upper bound. opp should be lower */
2077 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);
2078
2079 /* If not available, use the closest opp */
2080 if (opp == ERR_PTR(-ERANGE))
2081 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);
2082 } else {
2083 /* The freq is an lower bound. opp should be higher */
2084 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);
2085
2086 /* If not available, use the closest opp */
2087 if (opp == ERR_PTR(-ERANGE))
2088 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);
2089 }
2090
2091 return opp;
2092}
2093EXPORT_SYMBOL(devfreq_recommended_opp);
2094
2095/**
2096 * devfreq_register_opp_notifier() - Helper function to get devfreq notified
2097 * for any changes in the OPP availability
2098 * changes
2099 * @dev: The devfreq user device. (parent of devfreq)
2100 * @devfreq: The devfreq object.
2101 */
2102int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
2103{
2104 return dev_pm_opp_register_notifier(dev, &devfreq->nb);
2105}
2106EXPORT_SYMBOL(devfreq_register_opp_notifier);
2107
2108/**
2109 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
2110 * notified for any changes in the OPP
2111 * availability changes anymore.
2112 * @dev: The devfreq user device. (parent of devfreq)
2113 * @devfreq: The devfreq object.
2114 *
2115 * At exit() callback of devfreq_dev_profile, this must be included if
2116 * devfreq_recommended_opp is used.
2117 */
2118int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
2119{
2120 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
2121}
2122EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
2123
2124static void devm_devfreq_opp_release(struct device *dev, void *res)
2125{
2126 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
2127}
2128
2129/**
2130 * devm_devfreq_register_opp_notifier() - Resource-managed
2131 * devfreq_register_opp_notifier()
2132 * @dev: The devfreq user device. (parent of devfreq)
2133 * @devfreq: The devfreq object.
2134 */
2135int devm_devfreq_register_opp_notifier(struct device *dev,
2136 struct devfreq *devfreq)
2137{
2138 struct devfreq **ptr;
2139 int ret;
2140
2141 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
2142 if (!ptr)
2143 return -ENOMEM;
2144
2145 ret = devfreq_register_opp_notifier(dev, devfreq);
2146 if (ret) {
2147 devres_free(ptr);
2148 return ret;
2149 }
2150
2151 *ptr = devfreq;
2152 devres_add(dev, ptr);
2153
2154 return 0;
2155}
2156EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
2157
2158/**
2159 * devm_devfreq_unregister_opp_notifier() - Resource-managed
2160 * devfreq_unregister_opp_notifier()
2161 * @dev: The devfreq user device. (parent of devfreq)
2162 * @devfreq: The devfreq object.
2163 */
2164void devm_devfreq_unregister_opp_notifier(struct device *dev,
2165 struct devfreq *devfreq)
2166{
2167 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
2168 devm_devfreq_dev_match, devfreq));
2169}
2170EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
2171
2172/**
2173 * devfreq_register_notifier() - Register a driver with devfreq
2174 * @devfreq: The devfreq object.
2175 * @nb: The notifier block to register.
2176 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2177 */
2178int devfreq_register_notifier(struct devfreq *devfreq,
2179 struct notifier_block *nb,
2180 unsigned int list)
2181{
2182 int ret = 0;
2183
2184 if (!devfreq)
2185 return -EINVAL;
2186
2187 switch (list) {
2188 case DEVFREQ_TRANSITION_NOTIFIER:
2189 ret = srcu_notifier_chain_register(
2190 &devfreq->transition_notifier_list, nb);
2191 break;
2192 default:
2193 ret = -EINVAL;
2194 }
2195
2196 return ret;
2197}
2198EXPORT_SYMBOL(devfreq_register_notifier);
2199
2200/*
2201 * devfreq_unregister_notifier() - Unregister a driver with devfreq
2202 * @devfreq: The devfreq object.
2203 * @nb: The notifier block to be unregistered.
2204 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2205 */
2206int devfreq_unregister_notifier(struct devfreq *devfreq,
2207 struct notifier_block *nb,
2208 unsigned int list)
2209{
2210 int ret = 0;
2211
2212 if (!devfreq)
2213 return -EINVAL;
2214
2215 switch (list) {
2216 case DEVFREQ_TRANSITION_NOTIFIER:
2217 ret = srcu_notifier_chain_unregister(
2218 &devfreq->transition_notifier_list, nb);
2219 break;
2220 default:
2221 ret = -EINVAL;
2222 }
2223
2224 return ret;
2225}
2226EXPORT_SYMBOL(devfreq_unregister_notifier);
2227
2228struct devfreq_notifier_devres {
2229 struct devfreq *devfreq;
2230 struct notifier_block *nb;
2231 unsigned int list;
2232};
2233
2234static void devm_devfreq_notifier_release(struct device *dev, void *res)
2235{
2236 struct devfreq_notifier_devres *this = res;
2237
2238 devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
2239}
2240
2241/**
2242 * devm_devfreq_register_notifier()
2243 * - Resource-managed devfreq_register_notifier()
2244 * @dev: The devfreq user device. (parent of devfreq)
2245 * @devfreq: The devfreq object.
2246 * @nb: The notifier block to be unregistered.
2247 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2248 */
2249int devm_devfreq_register_notifier(struct device *dev,
2250 struct devfreq *devfreq,
2251 struct notifier_block *nb,
2252 unsigned int list)
2253{
2254 struct devfreq_notifier_devres *ptr;
2255 int ret;
2256
2257 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
2258 GFP_KERNEL);
2259 if (!ptr)
2260 return -ENOMEM;
2261
2262 ret = devfreq_register_notifier(devfreq, nb, list);
2263 if (ret) {
2264 devres_free(ptr);
2265 return ret;
2266 }
2267
2268 ptr->devfreq = devfreq;
2269 ptr->nb = nb;
2270 ptr->list = list;
2271 devres_add(dev, ptr);
2272
2273 return 0;
2274}
2275EXPORT_SYMBOL(devm_devfreq_register_notifier);
2276
2277/**
2278 * devm_devfreq_unregister_notifier()
2279 * - Resource-managed devfreq_unregister_notifier()
2280 * @dev: The devfreq user device. (parent of devfreq)
2281 * @devfreq: The devfreq object.
2282 * @nb: The notifier block to be unregistered.
2283 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2284 */
2285void devm_devfreq_unregister_notifier(struct device *dev,
2286 struct devfreq *devfreq,
2287 struct notifier_block *nb,
2288 unsigned int list)
2289{
2290 WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
2291 devm_devfreq_dev_match, devfreq));
2292}
2293EXPORT_SYMBOL(devm_devfreq_unregister_notifier);