projects/linux·blob v5.13 · refs

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