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