projects/linux·blob v5.10 · refs

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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework
4 * for Non-CPU Devices.
5 *
6 * Copyright (C) 2011 Samsung Electronics
7 * MyungJoo Ham <[email protected]>
8 */
9
10#include <linux/kernel.h>
11#include <linux/kmod.h>
12#include <linux/sched.h>
13#include <linux/debugfs.h>
14#include <linux/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_node - Get the devfreq device from devicetree
988 * @node - pointer to device_node
989 *
990 * return the instance of devfreq device
991 */
992struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
993{
994 struct devfreq *devfreq;
995
996 if (!node)
997 return ERR_PTR(-EINVAL);
998
999 mutex_lock(&devfreq_list_lock);
1000 list_for_each_entry(devfreq, &devfreq_list, node) {
1001 if (devfreq->dev.parent
1002 && devfreq->dev.parent->of_node == node) {
1003 mutex_unlock(&devfreq_list_lock);
1004 return devfreq;
1005 }
1006 }
1007 mutex_unlock(&devfreq_list_lock);
1008
1009 return ERR_PTR(-ENODEV);
1010}
1011
1012/*
1013 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
1014 * @dev - instance to the given device
1015 * @phandle_name - name of property holding a phandle value
1016 * @index - index into list of devfreq
1017 *
1018 * return the instance of devfreq device
1019 */
1020struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1021 const char *phandle_name, int index)
1022{
1023 struct device_node *node;
1024 struct devfreq *devfreq;
1025
1026 if (!dev || !phandle_name)
1027 return ERR_PTR(-EINVAL);
1028
1029 if (!dev->of_node)
1030 return ERR_PTR(-EINVAL);
1031
1032 node = of_parse_phandle(dev->of_node, phandle_name, index);
1033 if (!node)
1034 return ERR_PTR(-ENODEV);
1035
1036 devfreq = devfreq_get_devfreq_by_node(node);
1037 of_node_put(node);
1038
1039 return devfreq;
1040}
1041
1042#else
1043struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)
1044{
1045 return ERR_PTR(-ENODEV);
1046}
1047
1048struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
1049 const char *phandle_name, int index)
1050{
1051 return ERR_PTR(-ENODEV);
1052}
1053#endif /* CONFIG_OF */
1054EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);
1055EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
1056
1057/**
1058 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
1059 * @dev: the device from which to remove devfreq feature.
1060 * @devfreq: the devfreq instance to be removed
1061 */
1062void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)
1063{
1064 WARN_ON(devres_release(dev, devm_devfreq_dev_release,
1065 devm_devfreq_dev_match, devfreq));
1066}
1067EXPORT_SYMBOL(devm_devfreq_remove_device);
1068
1069/**
1070 * devfreq_suspend_device() - Suspend devfreq of a device.
1071 * @devfreq: the devfreq instance to be suspended
1072 *
1073 * This function is intended to be called by the pm callbacks
1074 * (e.g., runtime_suspend, suspend) of the device driver that
1075 * holds the devfreq.
1076 */
1077int devfreq_suspend_device(struct devfreq *devfreq)
1078{
1079 int ret;
1080
1081 if (!devfreq)
1082 return -EINVAL;
1083
1084 if (atomic_inc_return(&devfreq->suspend_count) > 1)
1085 return 0;
1086
1087 if (devfreq->governor) {
1088 ret = devfreq->governor->event_handler(devfreq,
1089 DEVFREQ_GOV_SUSPEND, NULL);
1090 if (ret)
1091 return ret;
1092 }
1093
1094 if (devfreq->suspend_freq) {
1095 mutex_lock(&devfreq->lock);
1096 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);
1097 mutex_unlock(&devfreq->lock);
1098 if (ret)
1099 return ret;
1100 }
1101
1102 return 0;
1103}
1104EXPORT_SYMBOL(devfreq_suspend_device);
1105
1106/**
1107 * devfreq_resume_device() - Resume devfreq of a device.
1108 * @devfreq: the devfreq instance to be resumed
1109 *
1110 * This function is intended to be called by the pm callbacks
1111 * (e.g., runtime_resume, resume) of the device driver that
1112 * holds the devfreq.
1113 */
1114int devfreq_resume_device(struct devfreq *devfreq)
1115{
1116 int ret;
1117
1118 if (!devfreq)
1119 return -EINVAL;
1120
1121 if (atomic_dec_return(&devfreq->suspend_count) >= 1)
1122 return 0;
1123
1124 if (devfreq->resume_freq) {
1125 mutex_lock(&devfreq->lock);
1126 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);
1127 mutex_unlock(&devfreq->lock);
1128 if (ret)
1129 return ret;
1130 }
1131
1132 if (devfreq->governor) {
1133 ret = devfreq->governor->event_handler(devfreq,
1134 DEVFREQ_GOV_RESUME, NULL);
1135 if (ret)
1136 return ret;
1137 }
1138
1139 return 0;
1140}
1141EXPORT_SYMBOL(devfreq_resume_device);
1142
1143/**
1144 * devfreq_suspend() - Suspend devfreq governors and devices
1145 *
1146 * Called during system wide Suspend/Hibernate cycles for suspending governors
1147 * and devices preserving the state for resume. On some platforms the devfreq
1148 * device must have precise state (frequency) after resume in order to provide
1149 * fully operating setup.
1150 */
1151void devfreq_suspend(void)
1152{
1153 struct devfreq *devfreq;
1154 int ret;
1155
1156 mutex_lock(&devfreq_list_lock);
1157 list_for_each_entry(devfreq, &devfreq_list, node) {
1158 ret = devfreq_suspend_device(devfreq);
1159 if (ret)
1160 dev_err(&devfreq->dev,
1161 "failed to suspend devfreq device\n");
1162 }
1163 mutex_unlock(&devfreq_list_lock);
1164}
1165
1166/**
1167 * devfreq_resume() - Resume devfreq governors and devices
1168 *
1169 * Called during system wide Suspend/Hibernate cycle for resuming governors and
1170 * devices that are suspended with devfreq_suspend().
1171 */
1172void devfreq_resume(void)
1173{
1174 struct devfreq *devfreq;
1175 int ret;
1176
1177 mutex_lock(&devfreq_list_lock);
1178 list_for_each_entry(devfreq, &devfreq_list, node) {
1179 ret = devfreq_resume_device(devfreq);
1180 if (ret)
1181 dev_warn(&devfreq->dev,
1182 "failed to resume devfreq device\n");
1183 }
1184 mutex_unlock(&devfreq_list_lock);
1185}
1186
1187/**
1188 * devfreq_add_governor() - Add devfreq governor
1189 * @governor: the devfreq governor to be added
1190 */
1191int devfreq_add_governor(struct devfreq_governor *governor)
1192{
1193 struct devfreq_governor *g;
1194 struct devfreq *devfreq;
1195 int err = 0;
1196
1197 if (!governor) {
1198 pr_err("%s: Invalid parameters.\n", __func__);
1199 return -EINVAL;
1200 }
1201
1202 mutex_lock(&devfreq_list_lock);
1203 g = find_devfreq_governor(governor->name);
1204 if (!IS_ERR(g)) {
1205 pr_err("%s: governor %s already registered\n", __func__,
1206 g->name);
1207 err = -EINVAL;
1208 goto err_out;
1209 }
1210
1211 list_add(&governor->node, &devfreq_governor_list);
1212
1213 list_for_each_entry(devfreq, &devfreq_list, node) {
1214 int ret = 0;
1215 struct device *dev = devfreq->dev.parent;
1216
1217 if (!strncmp(devfreq->governor_name, governor->name,
1218 DEVFREQ_NAME_LEN)) {
1219 /* The following should never occur */
1220 if (devfreq->governor) {
1221 dev_warn(dev,
1222 "%s: Governor %s already present\n",
1223 __func__, devfreq->governor->name);
1224 ret = devfreq->governor->event_handler(devfreq,
1225 DEVFREQ_GOV_STOP, NULL);
1226 if (ret) {
1227 dev_warn(dev,
1228 "%s: Governor %s stop = %d\n",
1229 __func__,
1230 devfreq->governor->name, ret);
1231 }
1232 /* Fall through */
1233 }
1234 devfreq->governor = governor;
1235 ret = devfreq->governor->event_handler(devfreq,
1236 DEVFREQ_GOV_START, NULL);
1237 if (ret) {
1238 dev_warn(dev, "%s: Governor %s start=%d\n",
1239 __func__, devfreq->governor->name,
1240 ret);
1241 }
1242 }
1243 }
1244
1245err_out:
1246 mutex_unlock(&devfreq_list_lock);
1247
1248 return err;
1249}
1250EXPORT_SYMBOL(devfreq_add_governor);
1251
1252/**
1253 * devfreq_remove_governor() - Remove devfreq feature from a device.
1254 * @governor: the devfreq governor to be removed
1255 */
1256int devfreq_remove_governor(struct devfreq_governor *governor)
1257{
1258 struct devfreq_governor *g;
1259 struct devfreq *devfreq;
1260 int err = 0;
1261
1262 if (!governor) {
1263 pr_err("%s: Invalid parameters.\n", __func__);
1264 return -EINVAL;
1265 }
1266
1267 mutex_lock(&devfreq_list_lock);
1268 g = find_devfreq_governor(governor->name);
1269 if (IS_ERR(g)) {
1270 pr_err("%s: governor %s not registered\n", __func__,
1271 governor->name);
1272 err = PTR_ERR(g);
1273 goto err_out;
1274 }
1275 list_for_each_entry(devfreq, &devfreq_list, node) {
1276 int ret;
1277 struct device *dev = devfreq->dev.parent;
1278
1279 if (!strncmp(devfreq->governor_name, governor->name,
1280 DEVFREQ_NAME_LEN)) {
1281 /* we should have a devfreq governor! */
1282 if (!devfreq->governor) {
1283 dev_warn(dev, "%s: Governor %s NOT present\n",
1284 __func__, governor->name);
1285 continue;
1286 /* Fall through */
1287 }
1288 ret = devfreq->governor->event_handler(devfreq,
1289 DEVFREQ_GOV_STOP, NULL);
1290 if (ret) {
1291 dev_warn(dev, "%s: Governor %s stop=%d\n",
1292 __func__, devfreq->governor->name,
1293 ret);
1294 }
1295 devfreq->governor = NULL;
1296 }
1297 }
1298
1299 list_del(&governor->node);
1300err_out:
1301 mutex_unlock(&devfreq_list_lock);
1302
1303 return err;
1304}
1305EXPORT_SYMBOL(devfreq_remove_governor);
1306
1307static ssize_t name_show(struct device *dev,
1308 struct device_attribute *attr, char *buf)
1309{
1310 struct devfreq *df = to_devfreq(dev);
1311 return sprintf(buf, "%s\n", dev_name(df->dev.parent));
1312}
1313static DEVICE_ATTR_RO(name);
1314
1315static ssize_t governor_show(struct device *dev,
1316 struct device_attribute *attr, char *buf)
1317{
1318 struct devfreq *df = to_devfreq(dev);
1319
1320 if (!df->governor)
1321 return -EINVAL;
1322
1323 return sprintf(buf, "%s\n", df->governor->name);
1324}
1325
1326static ssize_t governor_store(struct device *dev, struct device_attribute *attr,
1327 const char *buf, size_t count)
1328{
1329 struct devfreq *df = to_devfreq(dev);
1330 int ret;
1331 char str_governor[DEVFREQ_NAME_LEN + 1];
1332 const struct devfreq_governor *governor, *prev_governor;
1333
1334 if (!df->governor)
1335 return -EINVAL;
1336
1337 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);
1338 if (ret != 1)
1339 return -EINVAL;
1340
1341 mutex_lock(&devfreq_list_lock);
1342 governor = try_then_request_governor(str_governor);
1343 if (IS_ERR(governor)) {
1344 ret = PTR_ERR(governor);
1345 goto out;
1346 }
1347 if (df->governor == governor) {
1348 ret = 0;
1349 goto out;
1350 } else if (df->governor->immutable || governor->immutable) {
1351 ret = -EINVAL;
1352 goto out;
1353 }
1354
1355 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1356 if (ret) {
1357 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1358 __func__, df->governor->name, ret);
1359 goto out;
1360 }
1361
1362 prev_governor = df->governor;
1363 df->governor = governor;
1364 strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN);
1365 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1366 if (ret) {
1367 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1368 __func__, df->governor->name, ret);
1369 df->governor = prev_governor;
1370 strncpy(df->governor_name, prev_governor->name,
1371 DEVFREQ_NAME_LEN);
1372 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1373 if (ret) {
1374 dev_err(dev,
1375 "%s: reverting to Governor %s failed (%d)\n",
1376 __func__, df->governor_name, ret);
1377 df->governor = NULL;
1378 }
1379 }
1380out:
1381 mutex_unlock(&devfreq_list_lock);
1382
1383 if (!ret)
1384 ret = count;
1385 return ret;
1386}
1387static DEVICE_ATTR_RW(governor);
1388
1389static ssize_t available_governors_show(struct device *d,
1390 struct device_attribute *attr,
1391 char *buf)
1392{
1393 struct devfreq *df = to_devfreq(d);
1394 ssize_t count = 0;
1395
1396 if (!df->governor)
1397 return -EINVAL;
1398
1399 mutex_lock(&devfreq_list_lock);
1400
1401 /*
1402 * The devfreq with immutable governor (e.g., passive) shows
1403 * only own governor.
1404 */
1405 if (df->governor->immutable) {
1406 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,
1407 "%s ", df->governor_name);
1408 /*
1409 * The devfreq device shows the registered governor except for
1410 * immutable governors such as passive governor .
1411 */
1412 } else {
1413 struct devfreq_governor *governor;
1414
1415 list_for_each_entry(governor, &devfreq_governor_list, node) {
1416 if (governor->immutable)
1417 continue;
1418 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1419 "%s ", governor->name);
1420 }
1421 }
1422
1423 mutex_unlock(&devfreq_list_lock);
1424
1425 /* Truncate the trailing space */
1426 if (count)
1427 count--;
1428
1429 count += sprintf(&buf[count], "\n");
1430
1431 return count;
1432}
1433static DEVICE_ATTR_RO(available_governors);
1434
1435static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,
1436 char *buf)
1437{
1438 unsigned long freq;
1439 struct devfreq *df = to_devfreq(dev);
1440
1441 if (!df->profile)
1442 return -EINVAL;
1443
1444 if (df->profile->get_cur_freq &&
1445 !df->profile->get_cur_freq(df->dev.parent, &freq))
1446 return sprintf(buf, "%lu\n", freq);
1447
1448 return sprintf(buf, "%lu\n", df->previous_freq);
1449}
1450static DEVICE_ATTR_RO(cur_freq);
1451
1452static ssize_t target_freq_show(struct device *dev,
1453 struct device_attribute *attr, char *buf)
1454{
1455 struct devfreq *df = to_devfreq(dev);
1456
1457 return sprintf(buf, "%lu\n", df->previous_freq);
1458}
1459static DEVICE_ATTR_RO(target_freq);
1460
1461static ssize_t polling_interval_show(struct device *dev,
1462 struct device_attribute *attr, char *buf)
1463{
1464 struct devfreq *df = to_devfreq(dev);
1465
1466 if (!df->profile)
1467 return -EINVAL;
1468
1469 return sprintf(buf, "%d\n", df->profile->polling_ms);
1470}
1471
1472static ssize_t polling_interval_store(struct device *dev,
1473 struct device_attribute *attr,
1474 const char *buf, size_t count)
1475{
1476 struct devfreq *df = to_devfreq(dev);
1477 unsigned int value;
1478 int ret;
1479
1480 if (!df->governor)
1481 return -EINVAL;
1482
1483 ret = sscanf(buf, "%u", &value);
1484 if (ret != 1)
1485 return -EINVAL;
1486
1487 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);
1488 ret = count;
1489
1490 return ret;
1491}
1492static DEVICE_ATTR_RW(polling_interval);
1493
1494static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
1495 const char *buf, size_t count)
1496{
1497 struct devfreq *df = to_devfreq(dev);
1498 unsigned long value;
1499 int ret;
1500
1501 /*
1502 * Protect against theoretical sysfs writes between
1503 * device_add and dev_pm_qos_add_request
1504 */
1505 if (!dev_pm_qos_request_active(&df->user_min_freq_req))
1506 return -EAGAIN;
1507
1508 ret = sscanf(buf, "%lu", &value);
1509 if (ret != 1)
1510 return -EINVAL;
1511
1512 /* Round down to kHz for PM QoS */
1513 ret = dev_pm_qos_update_request(&df->user_min_freq_req,
1514 value / HZ_PER_KHZ);
1515 if (ret < 0)
1516 return ret;
1517
1518 return count;
1519}
1520
1521static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,
1522 char *buf)
1523{
1524 struct devfreq *df = to_devfreq(dev);
1525 unsigned long min_freq, max_freq;
1526
1527 mutex_lock(&df->lock);
1528 get_freq_range(df, &min_freq, &max_freq);
1529 mutex_unlock(&df->lock);
1530
1531 return sprintf(buf, "%lu\n", min_freq);
1532}
1533static DEVICE_ATTR_RW(min_freq);
1534
1535static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
1536 const char *buf, size_t count)
1537{
1538 struct devfreq *df = to_devfreq(dev);
1539 unsigned long value;
1540 int ret;
1541
1542 /*
1543 * Protect against theoretical sysfs writes between
1544 * device_add and dev_pm_qos_add_request
1545 */
1546 if (!dev_pm_qos_request_active(&df->user_max_freq_req))
1547 return -EINVAL;
1548
1549 ret = sscanf(buf, "%lu", &value);
1550 if (ret != 1)
1551 return -EINVAL;
1552
1553 /*
1554 * PM QoS frequencies are in kHz so we need to convert. Convert by
1555 * rounding upwards so that the acceptable interval never shrinks.
1556 *
1557 * For example if the user writes "666666666" to sysfs this value will
1558 * be converted to 666667 kHz and back to 666667000 Hz before an OPP
1559 * lookup, this ensures that an OPP of 666666666Hz is still accepted.
1560 *
1561 * A value of zero means "no limit".
1562 */
1563 if (value)
1564 value = DIV_ROUND_UP(value, HZ_PER_KHZ);
1565 else
1566 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;
1567
1568 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);
1569 if (ret < 0)
1570 return ret;
1571
1572 return count;
1573}
1574
1575static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,
1576 char *buf)
1577{
1578 struct devfreq *df = to_devfreq(dev);
1579 unsigned long min_freq, max_freq;
1580
1581 mutex_lock(&df->lock);
1582 get_freq_range(df, &min_freq, &max_freq);
1583 mutex_unlock(&df->lock);
1584
1585 return sprintf(buf, "%lu\n", max_freq);
1586}
1587static DEVICE_ATTR_RW(max_freq);
1588
1589static ssize_t available_frequencies_show(struct device *d,
1590 struct device_attribute *attr,
1591 char *buf)
1592{
1593 struct devfreq *df = to_devfreq(d);
1594 ssize_t count = 0;
1595 int i;
1596
1597 if (!df->profile)
1598 return -EINVAL;
1599
1600 mutex_lock(&df->lock);
1601
1602 for (i = 0; i < df->profile->max_state; i++)
1603 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),
1604 "%lu ", df->profile->freq_table[i]);
1605
1606 mutex_unlock(&df->lock);
1607 /* Truncate the trailing space */
1608 if (count)
1609 count--;
1610
1611 count += sprintf(&buf[count], "\n");
1612
1613 return count;
1614}
1615static DEVICE_ATTR_RO(available_frequencies);
1616
1617static ssize_t trans_stat_show(struct device *dev,
1618 struct device_attribute *attr, char *buf)
1619{
1620 struct devfreq *df = to_devfreq(dev);
1621 ssize_t len;
1622 int i, j;
1623 unsigned int max_state;
1624
1625 if (!df->profile)
1626 return -EINVAL;
1627 max_state = df->profile->max_state;
1628
1629 if (max_state == 0)
1630 return sprintf(buf, "Not Supported.\n");
1631
1632 mutex_lock(&df->lock);
1633 if (!df->stop_polling &&
1634 devfreq_update_status(df, df->previous_freq)) {
1635 mutex_unlock(&df->lock);
1636 return 0;
1637 }
1638 mutex_unlock(&df->lock);
1639
1640 len = sprintf(buf, " From : To\n");
1641 len += sprintf(buf + len, " :");
1642 for (i = 0; i < max_state; i++)
1643 len += sprintf(buf + len, "%10lu",
1644 df->profile->freq_table[i]);
1645
1646 len += sprintf(buf + len, " time(ms)\n");
1647
1648 for (i = 0; i < max_state; i++) {
1649 if (df->profile->freq_table[i]
1650 == df->previous_freq) {
1651 len += sprintf(buf + len, "*");
1652 } else {
1653 len += sprintf(buf + len, " ");
1654 }
1655 len += sprintf(buf + len, "%10lu:",
1656 df->profile->freq_table[i]);
1657 for (j = 0; j < max_state; j++)
1658 len += sprintf(buf + len, "%10u",
1659 df->stats.trans_table[(i * max_state) + j]);
1660
1661 len += sprintf(buf + len, "%10llu\n", (u64)
1662 jiffies64_to_msecs(df->stats.time_in_state[i]));
1663 }
1664
1665 len += sprintf(buf + len, "Total transition : %u\n",
1666 df->stats.total_trans);
1667 return len;
1668}
1669
1670static ssize_t trans_stat_store(struct device *dev,
1671 struct device_attribute *attr,
1672 const char *buf, size_t count)
1673{
1674 struct devfreq *df = to_devfreq(dev);
1675 int err, value;
1676
1677 if (!df->profile)
1678 return -EINVAL;
1679
1680 if (df->profile->max_state == 0)
1681 return count;
1682
1683 err = kstrtoint(buf, 10, &value);
1684 if (err || value != 0)
1685 return -EINVAL;
1686
1687 mutex_lock(&df->lock);
1688 memset(df->stats.time_in_state, 0, (df->profile->max_state *
1689 sizeof(*df->stats.time_in_state)));
1690 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),
1691 df->profile->max_state,
1692 df->profile->max_state));
1693 df->stats.total_trans = 0;
1694 df->stats.last_update = get_jiffies_64();
1695 mutex_unlock(&df->lock);
1696
1697 return count;
1698}
1699static DEVICE_ATTR_RW(trans_stat);
1700
1701static ssize_t timer_show(struct device *dev,
1702 struct device_attribute *attr, char *buf)
1703{
1704 struct devfreq *df = to_devfreq(dev);
1705
1706 if (!df->profile)
1707 return -EINVAL;
1708
1709 return sprintf(buf, "%s\n", timer_name[df->profile->timer]);
1710}
1711
1712static ssize_t timer_store(struct device *dev, struct device_attribute *attr,
1713 const char *buf, size_t count)
1714{
1715 struct devfreq *df = to_devfreq(dev);
1716 char str_timer[DEVFREQ_NAME_LEN + 1];
1717 int timer = -1;
1718 int ret = 0, i;
1719
1720 if (!df->governor || !df->profile)
1721 return -EINVAL;
1722
1723 ret = sscanf(buf, "%16s", str_timer);
1724 if (ret != 1)
1725 return -EINVAL;
1726
1727 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {
1728 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {
1729 timer = i;
1730 break;
1731 }
1732 }
1733
1734 if (timer < 0) {
1735 ret = -EINVAL;
1736 goto out;
1737 }
1738
1739 if (df->profile->timer == timer) {
1740 ret = 0;
1741 goto out;
1742 }
1743
1744 mutex_lock(&df->lock);
1745 df->profile->timer = timer;
1746 mutex_unlock(&df->lock);
1747
1748 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);
1749 if (ret) {
1750 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",
1751 __func__, df->governor->name, ret);
1752 goto out;
1753 }
1754
1755 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
1756 if (ret)
1757 dev_warn(dev, "%s: Governor %s not started(%d)\n",
1758 __func__, df->governor->name, ret);
1759out:
1760 return ret ? ret : count;
1761}
1762static DEVICE_ATTR_RW(timer);
1763
1764static struct attribute *devfreq_attrs[] = {
1765 &dev_attr_name.attr,
1766 &dev_attr_governor.attr,
1767 &dev_attr_available_governors.attr,
1768 &dev_attr_cur_freq.attr,
1769 &dev_attr_available_frequencies.attr,
1770 &dev_attr_target_freq.attr,
1771 &dev_attr_polling_interval.attr,
1772 &dev_attr_min_freq.attr,
1773 &dev_attr_max_freq.attr,
1774 &dev_attr_trans_stat.attr,
1775 &dev_attr_timer.attr,
1776 NULL,
1777};
1778ATTRIBUTE_GROUPS(devfreq);
1779
1780/**
1781 * devfreq_summary_show() - Show the summary of the devfreq devices
1782 * @s: seq_file instance to show the summary of devfreq devices
1783 * @data: not used
1784 *
1785 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.
1786 * It helps that user can know the detailed information of the devfreq devices.
1787 *
1788 * Return 0 always because it shows the information without any data change.
1789 */
1790static int devfreq_summary_show(struct seq_file *s, void *data)
1791{
1792 struct devfreq *devfreq;
1793 struct devfreq *p_devfreq = NULL;
1794 unsigned long cur_freq, min_freq, max_freq;
1795 unsigned int polling_ms;
1796 unsigned int timer;
1797
1798 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",
1799 "dev",
1800 "parent_dev",
1801 "governor",
1802 "timer",
1803 "polling_ms",
1804 "cur_freq_Hz",
1805 "min_freq_Hz",
1806 "max_freq_Hz");
1807 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",
1808 "------------------------------",
1809 "------------------------------",
1810 "---------------",
1811 "----------",
1812 "----------",
1813 "------------",
1814 "------------",
1815 "------------");
1816
1817 mutex_lock(&devfreq_list_lock);
1818
1819 list_for_each_entry_reverse(devfreq, &devfreq_list, node) {
1820#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
1821 if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE,
1822 DEVFREQ_NAME_LEN)) {
1823 struct devfreq_passive_data *data = devfreq->data;
1824
1825 if (data)
1826 p_devfreq = data->parent;
1827 } else {
1828 p_devfreq = NULL;
1829 }
1830#endif
1831
1832 mutex_lock(&devfreq->lock);
1833 cur_freq = devfreq->previous_freq;
1834 get_freq_range(devfreq, &min_freq, &max_freq);
1835 polling_ms = devfreq->profile->polling_ms;
1836 timer = devfreq->profile->timer;
1837 mutex_unlock(&devfreq->lock);
1838
1839 seq_printf(s,
1840 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",
1841 dev_name(&devfreq->dev),
1842 p_devfreq ? dev_name(&p_devfreq->dev) : "null",
1843 devfreq->governor_name,
1844 polling_ms ? timer_name[timer] : "null",
1845 polling_ms,
1846 cur_freq,
1847 min_freq,
1848 max_freq);
1849 }
1850
1851 mutex_unlock(&devfreq_list_lock);
1852
1853 return 0;
1854}
1855DEFINE_SHOW_ATTRIBUTE(devfreq_summary);
1856
1857static int __init devfreq_init(void)
1858{
1859 devfreq_class = class_create(THIS_MODULE, "devfreq");
1860 if (IS_ERR(devfreq_class)) {
1861 pr_err("%s: couldn't create class\n", __FILE__);
1862 return PTR_ERR(devfreq_class);
1863 }
1864
1865 devfreq_wq = create_freezable_workqueue("devfreq_wq");
1866 if (!devfreq_wq) {
1867 class_destroy(devfreq_class);
1868 pr_err("%s: couldn't create workqueue\n", __FILE__);
1869 return -ENOMEM;
1870 }
1871 devfreq_class->dev_groups = devfreq_groups;
1872
1873 devfreq_debugfs = debugfs_create_dir("devfreq", NULL);
1874 debugfs_create_file("devfreq_summary", 0444,
1875 devfreq_debugfs, NULL,
1876 &devfreq_summary_fops);
1877
1878 return 0;
1879}
1880subsys_initcall(devfreq_init);
1881
1882/*
1883 * The following are helper functions for devfreq user device drivers with
1884 * OPP framework.
1885 */
1886
1887/**
1888 * devfreq_recommended_opp() - Helper function to get proper OPP for the
1889 * freq value given to target callback.
1890 * @dev: The devfreq user device. (parent of devfreq)
1891 * @freq: The frequency given to target function
1892 * @flags: Flags handed from devfreq framework.
1893 *
1894 * The callers are required to call dev_pm_opp_put() for the returned OPP after
1895 * use.
1896 */
1897struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,
1898 unsigned long *freq,
1899 u32 flags)
1900{
1901 struct dev_pm_opp *opp;
1902
1903 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {
1904 /* The freq is an upper bound. opp should be lower */
1905 opp = dev_pm_opp_find_freq_floor(dev, freq);
1906
1907 /* If not available, use the closest opp */
1908 if (opp == ERR_PTR(-ERANGE))
1909 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1910 } else {
1911 /* The freq is an lower bound. opp should be higher */
1912 opp = dev_pm_opp_find_freq_ceil(dev, freq);
1913
1914 /* If not available, use the closest opp */
1915 if (opp == ERR_PTR(-ERANGE))
1916 opp = dev_pm_opp_find_freq_floor(dev, freq);
1917 }
1918
1919 return opp;
1920}
1921EXPORT_SYMBOL(devfreq_recommended_opp);
1922
1923/**
1924 * devfreq_register_opp_notifier() - Helper function to get devfreq notified
1925 * for any changes in the OPP availability
1926 * changes
1927 * @dev: The devfreq user device. (parent of devfreq)
1928 * @devfreq: The devfreq object.
1929 */
1930int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
1931{
1932 return dev_pm_opp_register_notifier(dev, &devfreq->nb);
1933}
1934EXPORT_SYMBOL(devfreq_register_opp_notifier);
1935
1936/**
1937 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq
1938 * notified for any changes in the OPP
1939 * availability changes anymore.
1940 * @dev: The devfreq user device. (parent of devfreq)
1941 * @devfreq: The devfreq object.
1942 *
1943 * At exit() callback of devfreq_dev_profile, this must be included if
1944 * devfreq_recommended_opp is used.
1945 */
1946int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
1947{
1948 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);
1949}
1950EXPORT_SYMBOL(devfreq_unregister_opp_notifier);
1951
1952static void devm_devfreq_opp_release(struct device *dev, void *res)
1953{
1954 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);
1955}
1956
1957/**
1958 * devm_devfreq_register_opp_notifier() - Resource-managed
1959 * devfreq_register_opp_notifier()
1960 * @dev: The devfreq user device. (parent of devfreq)
1961 * @devfreq: The devfreq object.
1962 */
1963int devm_devfreq_register_opp_notifier(struct device *dev,
1964 struct devfreq *devfreq)
1965{
1966 struct devfreq **ptr;
1967 int ret;
1968
1969 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);
1970 if (!ptr)
1971 return -ENOMEM;
1972
1973 ret = devfreq_register_opp_notifier(dev, devfreq);
1974 if (ret) {
1975 devres_free(ptr);
1976 return ret;
1977 }
1978
1979 *ptr = devfreq;
1980 devres_add(dev, ptr);
1981
1982 return 0;
1983}
1984EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);
1985
1986/**
1987 * devm_devfreq_unregister_opp_notifier() - Resource-managed
1988 * devfreq_unregister_opp_notifier()
1989 * @dev: The devfreq user device. (parent of devfreq)
1990 * @devfreq: The devfreq object.
1991 */
1992void devm_devfreq_unregister_opp_notifier(struct device *dev,
1993 struct devfreq *devfreq)
1994{
1995 WARN_ON(devres_release(dev, devm_devfreq_opp_release,
1996 devm_devfreq_dev_match, devfreq));
1997}
1998EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
1999
2000/**
2001 * devfreq_register_notifier() - Register a driver with devfreq
2002 * @devfreq: The devfreq object.
2003 * @nb: The notifier block to register.
2004 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2005 */
2006int devfreq_register_notifier(struct devfreq *devfreq,
2007 struct notifier_block *nb,
2008 unsigned int list)
2009{
2010 int ret = 0;
2011
2012 if (!devfreq)
2013 return -EINVAL;
2014
2015 switch (list) {
2016 case DEVFREQ_TRANSITION_NOTIFIER:
2017 ret = srcu_notifier_chain_register(
2018 &devfreq->transition_notifier_list, nb);
2019 break;
2020 default:
2021 ret = -EINVAL;
2022 }
2023
2024 return ret;
2025}
2026EXPORT_SYMBOL(devfreq_register_notifier);
2027
2028/*
2029 * devfreq_unregister_notifier() - Unregister a driver with devfreq
2030 * @devfreq: The devfreq object.
2031 * @nb: The notifier block to be unregistered.
2032 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2033 */
2034int devfreq_unregister_notifier(struct devfreq *devfreq,
2035 struct notifier_block *nb,
2036 unsigned int list)
2037{
2038 int ret = 0;
2039
2040 if (!devfreq)
2041 return -EINVAL;
2042
2043 switch (list) {
2044 case DEVFREQ_TRANSITION_NOTIFIER:
2045 ret = srcu_notifier_chain_unregister(
2046 &devfreq->transition_notifier_list, nb);
2047 break;
2048 default:
2049 ret = -EINVAL;
2050 }
2051
2052 return ret;
2053}
2054EXPORT_SYMBOL(devfreq_unregister_notifier);
2055
2056struct devfreq_notifier_devres {
2057 struct devfreq *devfreq;
2058 struct notifier_block *nb;
2059 unsigned int list;
2060};
2061
2062static void devm_devfreq_notifier_release(struct device *dev, void *res)
2063{
2064 struct devfreq_notifier_devres *this = res;
2065
2066 devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
2067}
2068
2069/**
2070 * devm_devfreq_register_notifier()
2071 * - Resource-managed devfreq_register_notifier()
2072 * @dev: The devfreq user device. (parent of devfreq)
2073 * @devfreq: The devfreq object.
2074 * @nb: The notifier block to be unregistered.
2075 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2076 */
2077int devm_devfreq_register_notifier(struct device *dev,
2078 struct devfreq *devfreq,
2079 struct notifier_block *nb,
2080 unsigned int list)
2081{
2082 struct devfreq_notifier_devres *ptr;
2083 int ret;
2084
2085 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
2086 GFP_KERNEL);
2087 if (!ptr)
2088 return -ENOMEM;
2089
2090 ret = devfreq_register_notifier(devfreq, nb, list);
2091 if (ret) {
2092 devres_free(ptr);
2093 return ret;
2094 }
2095
2096 ptr->devfreq = devfreq;
2097 ptr->nb = nb;
2098 ptr->list = list;
2099 devres_add(dev, ptr);
2100
2101 return 0;
2102}
2103EXPORT_SYMBOL(devm_devfreq_register_notifier);
2104
2105/**
2106 * devm_devfreq_unregister_notifier()
2107 * - Resource-managed devfreq_unregister_notifier()
2108 * @dev: The devfreq user device. (parent of devfreq)
2109 * @devfreq: The devfreq object.
2110 * @nb: The notifier block to be unregistered.
2111 * @list: DEVFREQ_TRANSITION_NOTIFIER.
2112 */
2113void devm_devfreq_unregister_notifier(struct device *dev,
2114 struct devfreq *devfreq,
2115 struct notifier_block *nb,
2116 unsigned int list)
2117{
2118 WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
2119 devm_devfreq_dev_match, devfreq));
2120}
2121EXPORT_SYMBOL(devm_devfreq_unregister_notifier);