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