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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework4 * for Non-CPU Devices.5 *6 * Copyright (C) 2011 Samsung Electronics7 * MyungJoo Ham <myungjoo.ham@samsung.com>8 */9 10#include <linux/kernel.h>11#include <linux/kmod.h>12#include <linux/sched.h>13#include <linux/debugfs.h>14#include <linux/devfreq_cooling.h>15#include <linux/errno.h>16#include <linux/err.h>17#include <linux/init.h>18#include <linux/export.h>19#include <linux/slab.h>20#include <linux/stat.h>21#include <linux/pm_opp.h>22#include <linux/devfreq.h>23#include <linux/workqueue.h>24#include <linux/platform_device.h>25#include <linux/list.h>26#include <linux/printk.h>27#include <linux/hrtimer.h>28#include <linux/of.h>29#include <linux/pm_qos.h>30#include <linux/units.h>31#include "governor.h"32 33#define CREATE_TRACE_POINTS34#include <trace/events/devfreq.h>35 36#define IS_SUPPORTED_FLAG(f, name) ((f & DEVFREQ_GOV_FLAG_##name) ? true : false)37#define IS_SUPPORTED_ATTR(f, name) ((f & DEVFREQ_GOV_ATTR_##name) ? true : false)38 39static struct class *devfreq_class;40static struct dentry *devfreq_debugfs;41 42/*43 * devfreq core provides delayed work based load monitoring helper44 * functions. Governors can use these or can implement their own45 * 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 pointer62 * @dev: device pointer used to lookup device devfreq.63 *64 * Search the list of device devfreqs and return the matched device's65 * devfreq info. devfreq_list_lock should be held by the caller.66 */67static struct devfreq *find_device_devfreq(struct device *dev)68{69 struct devfreq *tmp_devfreq;70 71 lockdep_assert_held(&devfreq_list_lock);72 73 if (IS_ERR_OR_NULL(dev)) {74 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__);75 return ERR_PTR(-EINVAL);76 }77 78 list_for_each_entry(tmp_devfreq, &devfreq_list, node) {79 if (tmp_devfreq->dev.parent == dev)80 return tmp_devfreq;81 }82 83 return ERR_PTR(-ENODEV);84}85 86static unsigned long find_available_min_freq(struct devfreq *devfreq)87{88 struct dev_pm_opp *opp;89 unsigned long min_freq = 0;90 91 opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &min_freq, 0);92 if (IS_ERR(opp))93 min_freq = 0;94 else95 dev_pm_opp_put(opp);96 97 return min_freq;98}99 100static unsigned long find_available_max_freq(struct devfreq *devfreq)101{102 struct dev_pm_opp *opp;103 unsigned long max_freq = ULONG_MAX;104 105 opp = dev_pm_opp_find_freq_floor_indexed(devfreq->dev.parent, &max_freq, 0);106 if (IS_ERR(opp))107 max_freq = 0;108 else109 dev_pm_opp_put(opp);110 111 return max_freq;112}113 114/**115 * devfreq_get_freq_range() - Get the current freq range116 * @devfreq: the devfreq instance117 * @min_freq: the min frequency118 * @max_freq: the max frequency119 *120 * This takes into consideration all constraints.121 */122void devfreq_get_freq_range(struct devfreq *devfreq,123 unsigned long *min_freq,124 unsigned long *max_freq)125{126 unsigned long *freq_table = devfreq->freq_table;127 s32 qos_min_freq, qos_max_freq;128 129 lockdep_assert_held(&devfreq->lock);130 131 /*132 * Initialize minimum/maximum frequency from freq table.133 * The devfreq drivers can initialize this in either ascending or134 * descending order and devfreq core supports both.135 */136 if (freq_table[0] < freq_table[devfreq->max_state - 1]) {137 *min_freq = freq_table[0];138 *max_freq = freq_table[devfreq->max_state - 1];139 } else {140 *min_freq = freq_table[devfreq->max_state - 1];141 *max_freq = freq_table[0];142 }143 144 /* Apply constraints from PM QoS */145 qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent,146 DEV_PM_QOS_MIN_FREQUENCY);147 qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent,148 DEV_PM_QOS_MAX_FREQUENCY);149 *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq);150 if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE)151 *max_freq = min(*max_freq,152 (unsigned long)HZ_PER_KHZ * qos_max_freq);153 154 /* Apply constraints from OPP interface */155 *min_freq = max(*min_freq, devfreq->scaling_min_freq);156 *max_freq = min(*max_freq, devfreq->scaling_max_freq);157 158 if (*min_freq > *max_freq)159 *min_freq = *max_freq;160}161EXPORT_SYMBOL(devfreq_get_freq_range);162 163/**164 * devfreq_get_freq_level() - Lookup freq_table for the frequency165 * @devfreq: the devfreq instance166 * @freq: the target frequency167 */168static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)169{170 int lev;171 172 for (lev = 0; lev < devfreq->max_state; lev++)173 if (freq == devfreq->freq_table[lev])174 return lev;175 176 return -EINVAL;177}178 179static int set_freq_table(struct devfreq *devfreq)180{181 struct dev_pm_opp *opp;182 unsigned long freq;183 int i, count;184 185 /* Initialize the freq_table from OPP table */186 count = dev_pm_opp_get_opp_count(devfreq->dev.parent);187 if (count <= 0)188 return -EINVAL;189 190 devfreq->max_state = count;191 devfreq->freq_table = devm_kcalloc(devfreq->dev.parent,192 devfreq->max_state,193 sizeof(*devfreq->freq_table),194 GFP_KERNEL);195 if (!devfreq->freq_table)196 return -ENOMEM;197 198 for (i = 0, freq = 0; i < devfreq->max_state; i++, freq++) {199 opp = dev_pm_opp_find_freq_ceil_indexed(devfreq->dev.parent, &freq, 0);200 if (IS_ERR(opp)) {201 devm_kfree(devfreq->dev.parent, devfreq->freq_table);202 return PTR_ERR(opp);203 }204 dev_pm_opp_put(opp);205 devfreq->freq_table[i] = freq;206 }207 208 return 0;209}210 211/**212 * devfreq_update_status() - Update statistics of devfreq behavior213 * @devfreq: the devfreq instance214 * @freq: the update target frequency215 */216int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)217{218 int lev, prev_lev, ret = 0;219 u64 cur_time;220 221 lockdep_assert_held(&devfreq->lock);222 cur_time = get_jiffies_64();223 224 /* Immediately exit if previous_freq is not initialized yet. */225 if (!devfreq->previous_freq)226 goto out;227 228 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);229 if (prev_lev < 0) {230 ret = prev_lev;231 goto out;232 }233 234 devfreq->stats.time_in_state[prev_lev] +=235 cur_time - devfreq->stats.last_update;236 237 lev = devfreq_get_freq_level(devfreq, freq);238 if (lev < 0) {239 ret = lev;240 goto out;241 }242 243 if (lev != prev_lev) {244 devfreq->stats.trans_table[245 (prev_lev * devfreq->max_state) + lev]++;246 devfreq->stats.total_trans++;247 }248 249out:250 devfreq->stats.last_update = cur_time;251 return ret;252}253EXPORT_SYMBOL(devfreq_update_status);254 255/**256 * find_devfreq_governor() - find devfreq governor from name257 * @name: name of the governor258 *259 * Search the list of devfreq governors and return the matched260 * 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 the283 * module if is not found.284 * @name: name of the governor285 *286 * Search the list of devfreq governors and request the module and try again287 * if is not found. This can happen when both drivers (the governor driver288 * and the driver that call devfreq_add_device) are built as modules.289 * devfreq_list_lock should be held by the caller. Returns the matched290 * 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 else312 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 else357 cur_freq = devfreq->previous_freq;358 359 freqs.old = cur_freq;360 freqs.new = new_freq;361 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);362 363 err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags);364 if (err) {365 freqs.new = cur_freq;366 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);367 return err;368 }369 370 /*371 * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE372 * and DEVFREQ_POSTCHANGE because for showing the correct frequency373 * change order of between devfreq device and passive devfreq device.374 */375 if (trace_devfreq_frequency_enabled() && new_freq != cur_freq)376 trace_devfreq_frequency(devfreq, new_freq, cur_freq);377 378 freqs.new = new_freq;379 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);380 381 if (devfreq_update_status(devfreq, new_freq))382 dev_warn(&devfreq->dev,383 "Couldn't update frequency transition information.\n");384 385 devfreq->previous_freq = new_freq;386 387 if (devfreq->suspend_freq)388 devfreq->resume_freq = new_freq;389 390 return err;391}392 393/**394 * devfreq_update_target() - Reevaluate the device and configure frequency395 * on the final stage.396 * @devfreq: the devfreq instance.397 * @freq: the new frequency of parent device. This argument398 * is only used for devfreq device using passive governor.399 *400 * Note: Lock devfreq->lock before calling devfreq_update_target. This function401 * should be only used by both update_devfreq() and devfreq governors.402 */403int devfreq_update_target(struct devfreq *devfreq, unsigned long freq)404{405 unsigned long min_freq, max_freq;406 int err = 0;407 u32 flags = 0;408 409 lockdep_assert_held(&devfreq->lock);410 411 if (!devfreq->governor)412 return -EINVAL;413 414 /* Reevaluate the proper frequency */415 err = devfreq->governor->get_target_freq(devfreq, &freq);416 if (err)417 return err;418 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);419 420 if (freq < min_freq) {421 freq = min_freq;422 flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */423 }424 if (freq > max_freq) {425 freq = max_freq;426 flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */427 }428 429 return devfreq_set_target(devfreq, freq, flags);430}431EXPORT_SYMBOL(devfreq_update_target);432 433/* Load monitoring helper functions for governors use */434 435/**436 * update_devfreq() - Reevaluate the device and configure frequency.437 * @devfreq: the devfreq instance.438 *439 * Note: Lock devfreq->lock before calling update_devfreq440 * This function is exported for governors.441 */442int update_devfreq(struct devfreq *devfreq)443{444 return devfreq_update_target(devfreq, 0L);445}446EXPORT_SYMBOL(update_devfreq);447 448/**449 * devfreq_monitor() - Periodically poll devfreq objects.450 * @work: the work struct used to run devfreq_monitor periodically.451 *452 */453static void devfreq_monitor(struct work_struct *work)454{455 int err;456 struct devfreq *devfreq = container_of(work,457 struct devfreq, work.work);458 459 mutex_lock(&devfreq->lock);460 err = update_devfreq(devfreq);461 if (err)462 dev_err(&devfreq->dev, "dvfs failed with (%d) error\n", err);463 464 if (devfreq->stop_polling)465 goto out;466 467 queue_delayed_work(devfreq_wq, &devfreq->work,468 msecs_to_jiffies(devfreq->profile->polling_ms));469 470out:471 mutex_unlock(&devfreq->lock);472 trace_devfreq_monitor(devfreq);473}474 475/**476 * devfreq_monitor_start() - Start load monitoring of devfreq instance477 * @devfreq: the devfreq instance.478 *479 * Helper function for starting devfreq device load monitoring. By default,480 * deferrable timer is used for load monitoring. But the users can change this481 * behavior using the "timer" type in devfreq_dev_profile. This function will be482 * called by devfreq governor in response to the DEVFREQ_GOV_START event483 * generated while adding a device to the devfreq framework.484 */485void devfreq_monitor_start(struct devfreq *devfreq)486{487 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))488 return;489 490 mutex_lock(&devfreq->lock);491 if (delayed_work_pending(&devfreq->work))492 goto out;493 494 switch (devfreq->profile->timer) {495 case DEVFREQ_TIMER_DEFERRABLE:496 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor);497 break;498 case DEVFREQ_TIMER_DELAYED:499 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor);500 break;501 default:502 goto out;503 }504 505 if (devfreq->profile->polling_ms)506 queue_delayed_work(devfreq_wq, &devfreq->work,507 msecs_to_jiffies(devfreq->profile->polling_ms));508 509out:510 devfreq->stop_polling = false;511 mutex_unlock(&devfreq->lock);512}513EXPORT_SYMBOL(devfreq_monitor_start);514 515/**516 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance517 * @devfreq: the devfreq instance.518 *519 * Helper function to stop devfreq device load monitoring. Function520 * to be called from governor in response to DEVFREQ_GOV_STOP521 * event when device is removed from devfreq framework.522 */523void devfreq_monitor_stop(struct devfreq *devfreq)524{525 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))526 return;527 528 mutex_lock(&devfreq->lock);529 if (devfreq->stop_polling) {530 mutex_unlock(&devfreq->lock);531 return;532 }533 534 devfreq->stop_polling = true;535 mutex_unlock(&devfreq->lock);536 cancel_delayed_work_sync(&devfreq->work);537}538EXPORT_SYMBOL(devfreq_monitor_stop);539 540/**541 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance542 * @devfreq: the devfreq instance.543 *544 * Helper function to suspend devfreq device load monitoring. Function545 * to be called from governor in response to DEVFREQ_GOV_SUSPEND546 * event or when polling interval is set to zero.547 *548 * Note: Though this function is same as devfreq_monitor_stop(),549 * intentionally kept separate to provide hooks for collecting550 * transition statistics.551 */552void devfreq_monitor_suspend(struct devfreq *devfreq)553{554 mutex_lock(&devfreq->lock);555 if (devfreq->stop_polling) {556 mutex_unlock(&devfreq->lock);557 return;558 }559 560 devfreq_update_status(devfreq, devfreq->previous_freq);561 devfreq->stop_polling = true;562 mutex_unlock(&devfreq->lock);563 564 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))565 return;566 567 cancel_delayed_work_sync(&devfreq->work);568}569EXPORT_SYMBOL(devfreq_monitor_suspend);570 571/**572 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance573 * @devfreq: the devfreq instance.574 *575 * Helper function to resume devfreq device load monitoring. Function576 * to be called from governor in response to DEVFREQ_GOV_RESUME577 * event or when polling interval is set to non-zero.578 */579void devfreq_monitor_resume(struct devfreq *devfreq)580{581 unsigned long freq;582 583 mutex_lock(&devfreq->lock);584 585 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))586 goto out_update;587 588 if (!devfreq->stop_polling)589 goto out;590 591 if (!delayed_work_pending(&devfreq->work) &&592 devfreq->profile->polling_ms)593 queue_delayed_work(devfreq_wq, &devfreq->work,594 msecs_to_jiffies(devfreq->profile->polling_ms));595 596out_update:597 devfreq->stats.last_update = get_jiffies_64();598 devfreq->stop_polling = false;599 600 if (devfreq->profile->get_cur_freq &&601 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))602 devfreq->previous_freq = freq;603 604out:605 mutex_unlock(&devfreq->lock);606}607EXPORT_SYMBOL(devfreq_monitor_resume);608 609/**610 * devfreq_update_interval() - Update device devfreq monitoring interval611 * @devfreq: the devfreq instance.612 * @delay: new polling interval to be set.613 *614 * Helper function to set new load monitoring polling interval. Function615 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event.616 */617void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay)618{619 unsigned int cur_delay = devfreq->profile->polling_ms;620 unsigned int new_delay = *delay;621 622 mutex_lock(&devfreq->lock);623 devfreq->profile->polling_ms = new_delay;624 625 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN))626 goto out;627 628 if (devfreq->stop_polling)629 goto out;630 631 /* if new delay is zero, stop polling */632 if (!new_delay) {633 mutex_unlock(&devfreq->lock);634 cancel_delayed_work_sync(&devfreq->work);635 return;636 }637 638 /* if current delay is zero, start polling with new delay */639 if (!cur_delay) {640 queue_delayed_work(devfreq_wq, &devfreq->work,641 msecs_to_jiffies(devfreq->profile->polling_ms));642 goto out;643 }644 645 /* if current delay is greater than new delay, restart polling */646 if (cur_delay > new_delay) {647 mutex_unlock(&devfreq->lock);648 cancel_delayed_work_sync(&devfreq->work);649 mutex_lock(&devfreq->lock);650 if (!devfreq->stop_polling)651 queue_delayed_work(devfreq_wq, &devfreq->work,652 msecs_to_jiffies(devfreq->profile->polling_ms));653 }654out:655 mutex_unlock(&devfreq->lock);656}657EXPORT_SYMBOL(devfreq_update_interval);658 659/**660 * devfreq_notifier_call() - Notify that the device frequency requirements661 * has been changed out of devfreq framework.662 * @nb: the notifier_block (supposed to be devfreq->nb)663 * @type: not used664 * @devp: not used665 *666 * Called by a notifier that uses devfreq->nb.667 */668static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,669 void *devp)670{671 struct devfreq *devfreq = container_of(nb, struct devfreq, nb);672 int err = -EINVAL;673 674 mutex_lock(&devfreq->lock);675 676 devfreq->scaling_min_freq = find_available_min_freq(devfreq);677 if (!devfreq->scaling_min_freq)678 goto out;679 680 devfreq->scaling_max_freq = find_available_max_freq(devfreq);681 if (!devfreq->scaling_max_freq) {682 devfreq->scaling_max_freq = ULONG_MAX;683 goto out;684 }685 686 err = update_devfreq(devfreq);687 688out:689 mutex_unlock(&devfreq->lock);690 if (err)691 dev_err(devfreq->dev.parent,692 "failed to update frequency from OPP notifier (%d)\n",693 err);694 695 return NOTIFY_OK;696}697 698/**699 * qos_notifier_call() - Common handler for QoS constraints.700 * @devfreq: the devfreq instance.701 */702static int qos_notifier_call(struct devfreq *devfreq)703{704 int err;705 706 mutex_lock(&devfreq->lock);707 err = update_devfreq(devfreq);708 mutex_unlock(&devfreq->lock);709 if (err)710 dev_err(devfreq->dev.parent,711 "failed to update frequency from PM QoS (%d)\n",712 err);713 714 return NOTIFY_OK;715}716 717/**718 * qos_min_notifier_call() - Callback for QoS min_freq changes.719 * @nb: Should be devfreq->nb_min720 * @val: not used721 * @ptr: not used722 */723static int qos_min_notifier_call(struct notifier_block *nb,724 unsigned long val, void *ptr)725{726 return qos_notifier_call(container_of(nb, struct devfreq, nb_min));727}728 729/**730 * qos_max_notifier_call() - Callback for QoS max_freq changes.731 * @nb: Should be devfreq->nb_max732 * @val: not used733 * @ptr: not used734 */735static int qos_max_notifier_call(struct notifier_block *nb,736 unsigned long val, void *ptr)737{738 return qos_notifier_call(container_of(nb, struct devfreq, nb_max));739}740 741/**742 * devfreq_dev_release() - Callback for struct device to release the device.743 * @dev: the devfreq device744 *745 * Remove devfreq from the list and release its resources.746 */747static void devfreq_dev_release(struct device *dev)748{749 struct devfreq *devfreq = to_devfreq(dev);750 int err;751 752 mutex_lock(&devfreq_list_lock);753 list_del(&devfreq->node);754 mutex_unlock(&devfreq_list_lock);755 756 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max,757 DEV_PM_QOS_MAX_FREQUENCY);758 if (err && err != -ENOENT)759 dev_warn(dev->parent,760 "Failed to remove max_freq notifier: %d\n", err);761 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min,762 DEV_PM_QOS_MIN_FREQUENCY);763 if (err && err != -ENOENT)764 dev_warn(dev->parent,765 "Failed to remove min_freq notifier: %d\n", err);766 767 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) {768 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req);769 if (err < 0)770 dev_warn(dev->parent,771 "Failed to remove max_freq request: %d\n", err);772 }773 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) {774 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req);775 if (err < 0)776 dev_warn(dev->parent,777 "Failed to remove min_freq request: %d\n", err);778 }779 780 if (devfreq->profile->exit)781 devfreq->profile->exit(devfreq->dev.parent);782 783 if (devfreq->opp_table)784 dev_pm_opp_put_opp_table(devfreq->opp_table);785 786 mutex_destroy(&devfreq->lock);787 srcu_cleanup_notifier_head(&devfreq->transition_notifier_list);788 kfree(devfreq);789}790 791static void create_sysfs_files(struct devfreq *devfreq,792 const struct devfreq_governor *gov);793static void remove_sysfs_files(struct devfreq *devfreq,794 const struct devfreq_governor *gov);795 796/**797 * devfreq_add_device() - Add devfreq feature to the device798 * @dev: the device to add devfreq feature.799 * @profile: device-specific profile to run devfreq.800 * @governor_name: name of the policy to choose frequency.801 * @data: devfreq driver pass to governors, governor should not change it.802 */803struct devfreq *devfreq_add_device(struct device *dev,804 struct devfreq_dev_profile *profile,805 const char *governor_name,806 void *data)807{808 struct devfreq *devfreq;809 struct devfreq_governor *governor;810 unsigned long min_freq, max_freq;811 int err = 0;812 813 if (!dev || !profile || !governor_name) {814 dev_err(dev, "%s: Invalid parameters.\n", __func__);815 return ERR_PTR(-EINVAL);816 }817 818 mutex_lock(&devfreq_list_lock);819 devfreq = find_device_devfreq(dev);820 mutex_unlock(&devfreq_list_lock);821 if (!IS_ERR(devfreq)) {822 dev_err(dev, "%s: devfreq device already exists!\n",823 __func__);824 err = -EINVAL;825 goto err_out;826 }827 828 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL);829 if (!devfreq) {830 err = -ENOMEM;831 goto err_out;832 }833 834 mutex_init(&devfreq->lock);835 mutex_lock(&devfreq->lock);836 devfreq->dev.parent = dev;837 devfreq->dev.class = devfreq_class;838 devfreq->dev.release = devfreq_dev_release;839 INIT_LIST_HEAD(&devfreq->node);840 devfreq->profile = profile;841 devfreq->previous_freq = profile->initial_freq;842 devfreq->last_status.current_frequency = profile->initial_freq;843 devfreq->data = data;844 devfreq->nb.notifier_call = devfreq_notifier_call;845 846 if (devfreq->profile->timer < 0847 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) {848 mutex_unlock(&devfreq->lock);849 err = -EINVAL;850 goto err_dev;851 }852 853 if (!devfreq->profile->max_state || !devfreq->profile->freq_table) {854 mutex_unlock(&devfreq->lock);855 err = set_freq_table(devfreq);856 if (err < 0)857 goto err_dev;858 mutex_lock(&devfreq->lock);859 } else {860 devfreq->freq_table = devfreq->profile->freq_table;861 devfreq->max_state = devfreq->profile->max_state;862 }863 864 devfreq->scaling_min_freq = find_available_min_freq(devfreq);865 if (!devfreq->scaling_min_freq) {866 mutex_unlock(&devfreq->lock);867 err = -EINVAL;868 goto err_dev;869 }870 871 devfreq->scaling_max_freq = find_available_max_freq(devfreq);872 if (!devfreq->scaling_max_freq) {873 mutex_unlock(&devfreq->lock);874 err = -EINVAL;875 goto err_dev;876 }877 878 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);879 880 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev);881 devfreq->opp_table = dev_pm_opp_get_opp_table(dev);882 if (IS_ERR(devfreq->opp_table))883 devfreq->opp_table = NULL;884 885 atomic_set(&devfreq->suspend_count, 0);886 887 dev_set_name(&devfreq->dev, "%s", dev_name(dev));888 err = device_register(&devfreq->dev);889 if (err) {890 mutex_unlock(&devfreq->lock);891 put_device(&devfreq->dev);892 goto err_out;893 }894 895 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev,896 array3_size(sizeof(unsigned int),897 devfreq->max_state,898 devfreq->max_state),899 GFP_KERNEL);900 if (!devfreq->stats.trans_table) {901 mutex_unlock(&devfreq->lock);902 err = -ENOMEM;903 goto err_devfreq;904 }905 906 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev,907 devfreq->max_state,908 sizeof(*devfreq->stats.time_in_state),909 GFP_KERNEL);910 if (!devfreq->stats.time_in_state) {911 mutex_unlock(&devfreq->lock);912 err = -ENOMEM;913 goto err_devfreq;914 }915 916 devfreq->stats.total_trans = 0;917 devfreq->stats.last_update = get_jiffies_64();918 919 srcu_init_notifier_head(&devfreq->transition_notifier_list);920 921 mutex_unlock(&devfreq->lock);922 923 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req,924 DEV_PM_QOS_MIN_FREQUENCY, 0);925 if (err < 0)926 goto err_devfreq;927 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req,928 DEV_PM_QOS_MAX_FREQUENCY,929 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);930 if (err < 0)931 goto err_devfreq;932 933 devfreq->nb_min.notifier_call = qos_min_notifier_call;934 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min,935 DEV_PM_QOS_MIN_FREQUENCY);936 if (err)937 goto err_devfreq;938 939 devfreq->nb_max.notifier_call = qos_max_notifier_call;940 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max,941 DEV_PM_QOS_MAX_FREQUENCY);942 if (err)943 goto err_devfreq;944 945 mutex_lock(&devfreq_list_lock);946 947 governor = try_then_request_governor(governor_name);948 if (IS_ERR(governor)) {949 dev_err(dev, "%s: Unable to find governor for the device\n",950 __func__);951 err = PTR_ERR(governor);952 goto err_init;953 }954 955 devfreq->governor = governor;956 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START,957 NULL);958 if (err) {959 dev_err_probe(dev, err,960 "%s: Unable to start governor for the device\n",961 __func__);962 goto err_init;963 }964 create_sysfs_files(devfreq, devfreq->governor);965 966 list_add(&devfreq->node, &devfreq_list);967 968 mutex_unlock(&devfreq_list_lock);969 970 if (devfreq->profile->is_cooling_device) {971 devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL);972 if (IS_ERR(devfreq->cdev))973 devfreq->cdev = NULL;974 }975 976 return devfreq;977 978err_init:979 mutex_unlock(&devfreq_list_lock);980err_devfreq:981 devfreq_remove_device(devfreq);982 devfreq = NULL;983err_dev:984 kfree(devfreq);985err_out:986 return ERR_PTR(err);987}988EXPORT_SYMBOL(devfreq_add_device);989 990/**991 * devfreq_remove_device() - Remove devfreq feature from a device.992 * @devfreq: the devfreq instance to be removed993 *994 * The opposite of devfreq_add_device().995 */996int devfreq_remove_device(struct devfreq *devfreq)997{998 if (!devfreq)999 return -EINVAL;1000 1001 devfreq_cooling_unregister(devfreq->cdev);1002 1003 if (devfreq->governor) {1004 devfreq->governor->event_handler(devfreq,1005 DEVFREQ_GOV_STOP, NULL);1006 remove_sysfs_files(devfreq, devfreq->governor);1007 }1008 1009 device_unregister(&devfreq->dev);1010 1011 return 0;1012}1013EXPORT_SYMBOL(devfreq_remove_device);1014 1015static int devm_devfreq_dev_match(struct device *dev, void *res, void *data)1016{1017 struct devfreq **r = res;1018 1019 if (WARN_ON(!r || !*r))1020 return 0;1021 1022 return *r == data;1023}1024 1025static void devm_devfreq_dev_release(struct device *dev, void *res)1026{1027 devfreq_remove_device(*(struct devfreq **)res);1028}1029 1030/**1031 * devm_devfreq_add_device() - Resource-managed devfreq_add_device()1032 * @dev: the device to add devfreq feature.1033 * @profile: device-specific profile to run devfreq.1034 * @governor_name: name of the policy to choose frequency.1035 * @data: devfreq driver pass to governors, governor should not change it.1036 *1037 * This function manages automatically the memory of devfreq device using device1038 * resource management and simplify the free operation for memory of devfreq1039 * device.1040 */1041struct devfreq *devm_devfreq_add_device(struct device *dev,1042 struct devfreq_dev_profile *profile,1043 const char *governor_name,1044 void *data)1045{1046 struct devfreq **ptr, *devfreq;1047 1048 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL);1049 if (!ptr)1050 return ERR_PTR(-ENOMEM);1051 1052 devfreq = devfreq_add_device(dev, profile, governor_name, data);1053 if (IS_ERR(devfreq)) {1054 devres_free(ptr);1055 return devfreq;1056 }1057 1058 *ptr = devfreq;1059 devres_add(dev, ptr);1060 1061 return devfreq;1062}1063EXPORT_SYMBOL(devm_devfreq_add_device);1064 1065#ifdef CONFIG_OF1066/*1067 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree1068 * @node - pointer to device_node1069 *1070 * return the instance of devfreq device1071 */1072struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)1073{1074 struct devfreq *devfreq;1075 1076 if (!node)1077 return ERR_PTR(-EINVAL);1078 1079 mutex_lock(&devfreq_list_lock);1080 list_for_each_entry(devfreq, &devfreq_list, node) {1081 if (devfreq->dev.parent1082 && device_match_of_node(devfreq->dev.parent, node)) {1083 mutex_unlock(&devfreq_list_lock);1084 return devfreq;1085 }1086 }1087 mutex_unlock(&devfreq_list_lock);1088 1089 return ERR_PTR(-ENODEV);1090}1091 1092/*1093 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree1094 * @dev - instance to the given device1095 * @phandle_name - name of property holding a phandle value1096 * @index - index into list of devfreq1097 *1098 * return the instance of devfreq device1099 */1100struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,1101 const char *phandle_name, int index)1102{1103 struct device_node *node;1104 struct devfreq *devfreq;1105 1106 if (!dev || !phandle_name)1107 return ERR_PTR(-EINVAL);1108 1109 if (!dev->of_node)1110 return ERR_PTR(-EINVAL);1111 1112 node = of_parse_phandle(dev->of_node, phandle_name, index);1113 if (!node)1114 return ERR_PTR(-ENODEV);1115 1116 devfreq = devfreq_get_devfreq_by_node(node);1117 of_node_put(node);1118 1119 return devfreq;1120}1121 1122#else1123struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node)1124{1125 return ERR_PTR(-ENODEV);1126}1127 1128struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,1129 const char *phandle_name, int index)1130{1131 return ERR_PTR(-ENODEV);1132}1133#endif /* CONFIG_OF */1134EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node);1135EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);1136 1137/**1138 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()1139 * @dev: the device from which to remove devfreq feature.1140 * @devfreq: the devfreq instance to be removed1141 */1142void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq)1143{1144 WARN_ON(devres_release(dev, devm_devfreq_dev_release,1145 devm_devfreq_dev_match, devfreq));1146}1147EXPORT_SYMBOL(devm_devfreq_remove_device);1148 1149/**1150 * devfreq_suspend_device() - Suspend devfreq of a device.1151 * @devfreq: the devfreq instance to be suspended1152 *1153 * This function is intended to be called by the pm callbacks1154 * (e.g., runtime_suspend, suspend) of the device driver that1155 * holds the devfreq.1156 */1157int devfreq_suspend_device(struct devfreq *devfreq)1158{1159 int ret;1160 1161 if (!devfreq)1162 return -EINVAL;1163 1164 if (atomic_inc_return(&devfreq->suspend_count) > 1)1165 return 0;1166 1167 if (devfreq->governor) {1168 ret = devfreq->governor->event_handler(devfreq,1169 DEVFREQ_GOV_SUSPEND, NULL);1170 if (ret)1171 return ret;1172 }1173 1174 if (devfreq->suspend_freq) {1175 mutex_lock(&devfreq->lock);1176 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0);1177 mutex_unlock(&devfreq->lock);1178 if (ret)1179 return ret;1180 }1181 1182 return 0;1183}1184EXPORT_SYMBOL(devfreq_suspend_device);1185 1186/**1187 * devfreq_resume_device() - Resume devfreq of a device.1188 * @devfreq: the devfreq instance to be resumed1189 *1190 * This function is intended to be called by the pm callbacks1191 * (e.g., runtime_resume, resume) of the device driver that1192 * holds the devfreq.1193 */1194int devfreq_resume_device(struct devfreq *devfreq)1195{1196 int ret;1197 1198 if (!devfreq)1199 return -EINVAL;1200 1201 if (atomic_dec_return(&devfreq->suspend_count) >= 1)1202 return 0;1203 1204 if (devfreq->resume_freq) {1205 mutex_lock(&devfreq->lock);1206 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0);1207 mutex_unlock(&devfreq->lock);1208 if (ret)1209 return ret;1210 }1211 1212 if (devfreq->governor) {1213 ret = devfreq->governor->event_handler(devfreq,1214 DEVFREQ_GOV_RESUME, NULL);1215 if (ret)1216 return ret;1217 }1218 1219 return 0;1220}1221EXPORT_SYMBOL(devfreq_resume_device);1222 1223/**1224 * devfreq_suspend() - Suspend devfreq governors and devices1225 *1226 * Called during system wide Suspend/Hibernate cycles for suspending governors1227 * and devices preserving the state for resume. On some platforms the devfreq1228 * device must have precise state (frequency) after resume in order to provide1229 * fully operating setup.1230 */1231void devfreq_suspend(void)1232{1233 struct devfreq *devfreq;1234 int ret;1235 1236 mutex_lock(&devfreq_list_lock);1237 list_for_each_entry(devfreq, &devfreq_list, node) {1238 ret = devfreq_suspend_device(devfreq);1239 if (ret)1240 dev_err(&devfreq->dev,1241 "failed to suspend devfreq device\n");1242 }1243 mutex_unlock(&devfreq_list_lock);1244}1245 1246/**1247 * devfreq_resume() - Resume devfreq governors and devices1248 *1249 * Called during system wide Suspend/Hibernate cycle for resuming governors and1250 * devices that are suspended with devfreq_suspend().1251 */1252void devfreq_resume(void)1253{1254 struct devfreq *devfreq;1255 int ret;1256 1257 mutex_lock(&devfreq_list_lock);1258 list_for_each_entry(devfreq, &devfreq_list, node) {1259 ret = devfreq_resume_device(devfreq);1260 if (ret)1261 dev_warn(&devfreq->dev,1262 "failed to resume devfreq device\n");1263 }1264 mutex_unlock(&devfreq_list_lock);1265}1266 1267/**1268 * devfreq_add_governor() - Add devfreq governor1269 * @governor: the devfreq governor to be added1270 */1271int devfreq_add_governor(struct devfreq_governor *governor)1272{1273 struct devfreq_governor *g;1274 struct devfreq *devfreq;1275 int err = 0;1276 1277 if (!governor) {1278 pr_err("%s: Invalid parameters.\n", __func__);1279 return -EINVAL;1280 }1281 1282 mutex_lock(&devfreq_list_lock);1283 g = find_devfreq_governor(governor->name);1284 if (!IS_ERR(g)) {1285 pr_err("%s: governor %s already registered\n", __func__,1286 g->name);1287 err = -EINVAL;1288 goto err_out;1289 }1290 1291 list_add(&governor->node, &devfreq_governor_list);1292 1293 list_for_each_entry(devfreq, &devfreq_list, node) {1294 int ret = 0;1295 struct device *dev = devfreq->dev.parent;1296 1297 if (!strncmp(devfreq->governor->name, governor->name,1298 DEVFREQ_NAME_LEN)) {1299 /* The following should never occur */1300 if (devfreq->governor) {1301 dev_warn(dev,1302 "%s: Governor %s already present\n",1303 __func__, devfreq->governor->name);1304 ret = devfreq->governor->event_handler(devfreq,1305 DEVFREQ_GOV_STOP, NULL);1306 if (ret) {1307 dev_warn(dev,1308 "%s: Governor %s stop = %d\n",1309 __func__,1310 devfreq->governor->name, ret);1311 }1312 /* Fall through */1313 }1314 devfreq->governor = governor;1315 ret = devfreq->governor->event_handler(devfreq,1316 DEVFREQ_GOV_START, NULL);1317 if (ret) {1318 dev_warn(dev, "%s: Governor %s start=%d\n",1319 __func__, devfreq->governor->name,1320 ret);1321 }1322 }1323 }1324 1325err_out:1326 mutex_unlock(&devfreq_list_lock);1327 1328 return err;1329}1330EXPORT_SYMBOL(devfreq_add_governor);1331 1332static void devm_devfreq_remove_governor(void *governor)1333{1334 WARN_ON(devfreq_remove_governor(governor));1335}1336 1337/**1338 * devm_devfreq_add_governor() - Add devfreq governor1339 * @dev: device which adds devfreq governor1340 * @governor: the devfreq governor to be added1341 *1342 * This is a resource-managed variant of devfreq_add_governor().1343 */1344int devm_devfreq_add_governor(struct device *dev,1345 struct devfreq_governor *governor)1346{1347 int err;1348 1349 err = devfreq_add_governor(governor);1350 if (err)1351 return err;1352 1353 return devm_add_action_or_reset(dev, devm_devfreq_remove_governor,1354 governor);1355}1356EXPORT_SYMBOL(devm_devfreq_add_governor);1357 1358/**1359 * devfreq_remove_governor() - Remove devfreq feature from a device.1360 * @governor: the devfreq governor to be removed1361 */1362int devfreq_remove_governor(struct devfreq_governor *governor)1363{1364 struct devfreq_governor *g;1365 struct devfreq *devfreq;1366 int err = 0;1367 1368 if (!governor) {1369 pr_err("%s: Invalid parameters.\n", __func__);1370 return -EINVAL;1371 }1372 1373 mutex_lock(&devfreq_list_lock);1374 g = find_devfreq_governor(governor->name);1375 if (IS_ERR(g)) {1376 pr_err("%s: governor %s not registered\n", __func__,1377 governor->name);1378 err = PTR_ERR(g);1379 goto err_out;1380 }1381 list_for_each_entry(devfreq, &devfreq_list, node) {1382 int ret;1383 struct device *dev = devfreq->dev.parent;1384 1385 if (!strncmp(devfreq->governor->name, governor->name,1386 DEVFREQ_NAME_LEN)) {1387 /* we should have a devfreq governor! */1388 if (!devfreq->governor) {1389 dev_warn(dev, "%s: Governor %s NOT present\n",1390 __func__, governor->name);1391 continue;1392 /* Fall through */1393 }1394 ret = devfreq->governor->event_handler(devfreq,1395 DEVFREQ_GOV_STOP, NULL);1396 if (ret) {1397 dev_warn(dev, "%s: Governor %s stop=%d\n",1398 __func__, devfreq->governor->name,1399 ret);1400 }1401 devfreq->governor = NULL;1402 }1403 }1404 1405 list_del(&governor->node);1406err_out:1407 mutex_unlock(&devfreq_list_lock);1408 1409 return err;1410}1411EXPORT_SYMBOL(devfreq_remove_governor);1412 1413static ssize_t name_show(struct device *dev,1414 struct device_attribute *attr, char *buf)1415{1416 struct devfreq *df = to_devfreq(dev);1417 return sprintf(buf, "%s\n", dev_name(df->dev.parent));1418}1419static DEVICE_ATTR_RO(name);1420 1421static ssize_t governor_show(struct device *dev,1422 struct device_attribute *attr, char *buf)1423{1424 struct devfreq *df = to_devfreq(dev);1425 1426 if (!df->governor)1427 return -EINVAL;1428 1429 return sprintf(buf, "%s\n", df->governor->name);1430}1431 1432static ssize_t governor_store(struct device *dev, struct device_attribute *attr,1433 const char *buf, size_t count)1434{1435 struct devfreq *df = to_devfreq(dev);1436 int ret;1437 char str_governor[DEVFREQ_NAME_LEN + 1];1438 const struct devfreq_governor *governor, *prev_governor;1439 1440 if (!df->governor)1441 return -EINVAL;1442 1443 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor);1444 if (ret != 1)1445 return -EINVAL;1446 1447 mutex_lock(&devfreq_list_lock);1448 governor = try_then_request_governor(str_governor);1449 if (IS_ERR(governor)) {1450 ret = PTR_ERR(governor);1451 goto out;1452 }1453 if (df->governor == governor) {1454 ret = 0;1455 goto out;1456 } else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)1457 || IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) {1458 ret = -EINVAL;1459 goto out;1460 }1461 1462 /*1463 * Stop the current governor and remove the specific sysfs files1464 * which depend on current governor.1465 */1466 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);1467 if (ret) {1468 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",1469 __func__, df->governor->name, ret);1470 goto out;1471 }1472 remove_sysfs_files(df, df->governor);1473 1474 /*1475 * Start the new governor and create the specific sysfs files1476 * which depend on the new governor.1477 */1478 prev_governor = df->governor;1479 df->governor = governor;1480 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);1481 if (ret) {1482 dev_warn(dev, "%s: Governor %s not started(%d)\n",1483 __func__, df->governor->name, ret);1484 1485 /* Restore previous governor */1486 df->governor = prev_governor;1487 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);1488 if (ret) {1489 dev_err(dev,1490 "%s: reverting to Governor %s failed (%d)\n",1491 __func__, prev_governor->name, ret);1492 df->governor = NULL;1493 goto out;1494 }1495 }1496 1497 /*1498 * Create the sysfs files for the new governor. But if failed to start1499 * the new governor, restore the sysfs files of previous governor.1500 */1501 create_sysfs_files(df, df->governor);1502 1503out:1504 mutex_unlock(&devfreq_list_lock);1505 1506 if (!ret)1507 ret = count;1508 return ret;1509}1510static DEVICE_ATTR_RW(governor);1511 1512static ssize_t available_governors_show(struct device *d,1513 struct device_attribute *attr,1514 char *buf)1515{1516 struct devfreq *df = to_devfreq(d);1517 ssize_t count = 0;1518 1519 if (!df->governor)1520 return -EINVAL;1521 1522 mutex_lock(&devfreq_list_lock);1523 1524 /*1525 * The devfreq with immutable governor (e.g., passive) shows1526 * only own governor.1527 */1528 if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) {1529 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN,1530 "%s ", df->governor->name);1531 /*1532 * The devfreq device shows the registered governor except for1533 * immutable governors such as passive governor .1534 */1535 } else {1536 struct devfreq_governor *governor;1537 1538 list_for_each_entry(governor, &devfreq_governor_list, node) {1539 if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE))1540 continue;1541 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),1542 "%s ", governor->name);1543 }1544 }1545 1546 mutex_unlock(&devfreq_list_lock);1547 1548 /* Truncate the trailing space */1549 if (count)1550 count--;1551 1552 count += sprintf(&buf[count], "\n");1553 1554 return count;1555}1556static DEVICE_ATTR_RO(available_governors);1557 1558static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr,1559 char *buf)1560{1561 unsigned long freq;1562 struct devfreq *df = to_devfreq(dev);1563 1564 if (!df->profile)1565 return -EINVAL;1566 1567 if (df->profile->get_cur_freq &&1568 !df->profile->get_cur_freq(df->dev.parent, &freq))1569 return sprintf(buf, "%lu\n", freq);1570 1571 return sprintf(buf, "%lu\n", df->previous_freq);1572}1573static DEVICE_ATTR_RO(cur_freq);1574 1575static ssize_t target_freq_show(struct device *dev,1576 struct device_attribute *attr, char *buf)1577{1578 struct devfreq *df = to_devfreq(dev);1579 1580 return sprintf(buf, "%lu\n", df->previous_freq);1581}1582static DEVICE_ATTR_RO(target_freq);1583 1584static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,1585 const char *buf, size_t count)1586{1587 struct devfreq *df = to_devfreq(dev);1588 unsigned long value;1589 int ret;1590 1591 /*1592 * Protect against theoretical sysfs writes between1593 * device_add and dev_pm_qos_add_request1594 */1595 if (!dev_pm_qos_request_active(&df->user_min_freq_req))1596 return -EAGAIN;1597 1598 ret = sscanf(buf, "%lu", &value);1599 if (ret != 1)1600 return -EINVAL;1601 1602 /* Round down to kHz for PM QoS */1603 ret = dev_pm_qos_update_request(&df->user_min_freq_req,1604 value / HZ_PER_KHZ);1605 if (ret < 0)1606 return ret;1607 1608 return count;1609}1610 1611static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr,1612 char *buf)1613{1614 struct devfreq *df = to_devfreq(dev);1615 unsigned long min_freq, max_freq;1616 1617 mutex_lock(&df->lock);1618 devfreq_get_freq_range(df, &min_freq, &max_freq);1619 mutex_unlock(&df->lock);1620 1621 return sprintf(buf, "%lu\n", min_freq);1622}1623static DEVICE_ATTR_RW(min_freq);1624 1625static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,1626 const char *buf, size_t count)1627{1628 struct devfreq *df = to_devfreq(dev);1629 unsigned long value;1630 int ret;1631 1632 /*1633 * Protect against theoretical sysfs writes between1634 * device_add and dev_pm_qos_add_request1635 */1636 if (!dev_pm_qos_request_active(&df->user_max_freq_req))1637 return -EINVAL;1638 1639 ret = sscanf(buf, "%lu", &value);1640 if (ret != 1)1641 return -EINVAL;1642 1643 /*1644 * PM QoS frequencies are in kHz so we need to convert. Convert by1645 * rounding upwards so that the acceptable interval never shrinks.1646 *1647 * For example if the user writes "666666666" to sysfs this value will1648 * be converted to 666667 kHz and back to 666667000 Hz before an OPP1649 * lookup, this ensures that an OPP of 666666666Hz is still accepted.1650 *1651 * A value of zero means "no limit".1652 */1653 if (value)1654 value = DIV_ROUND_UP(value, HZ_PER_KHZ);1655 else1656 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE;1657 1658 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value);1659 if (ret < 0)1660 return ret;1661 1662 return count;1663}1664 1665static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr,1666 char *buf)1667{1668 struct devfreq *df = to_devfreq(dev);1669 unsigned long min_freq, max_freq;1670 1671 mutex_lock(&df->lock);1672 devfreq_get_freq_range(df, &min_freq, &max_freq);1673 mutex_unlock(&df->lock);1674 1675 return sprintf(buf, "%lu\n", max_freq);1676}1677static DEVICE_ATTR_RW(max_freq);1678 1679static ssize_t available_frequencies_show(struct device *d,1680 struct device_attribute *attr,1681 char *buf)1682{1683 struct devfreq *df = to_devfreq(d);1684 ssize_t count = 0;1685 int i;1686 1687 if (!df->profile)1688 return -EINVAL;1689 1690 mutex_lock(&df->lock);1691 1692 for (i = 0; i < df->max_state; i++)1693 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2),1694 "%lu ", df->freq_table[i]);1695 1696 mutex_unlock(&df->lock);1697 /* Truncate the trailing space */1698 if (count)1699 count--;1700 1701 count += sprintf(&buf[count], "\n");1702 1703 return count;1704}1705static DEVICE_ATTR_RO(available_frequencies);1706 1707static ssize_t trans_stat_show(struct device *dev,1708 struct device_attribute *attr, char *buf)1709{1710 struct devfreq *df = to_devfreq(dev);1711 ssize_t len = 0;1712 int i, j;1713 unsigned int max_state;1714 1715 if (!df->profile)1716 return -EINVAL;1717 max_state = df->max_state;1718 1719 if (max_state == 0)1720 return sysfs_emit(buf, "Not Supported.\n");1721 1722 mutex_lock(&df->lock);1723 if (!df->stop_polling &&1724 devfreq_update_status(df, df->previous_freq)) {1725 mutex_unlock(&df->lock);1726 return 0;1727 }1728 mutex_unlock(&df->lock);1729 1730 len += sysfs_emit_at(buf, len, " From : To\n");1731 len += sysfs_emit_at(buf, len, " :");1732 for (i = 0; i < max_state; i++) {1733 if (len >= PAGE_SIZE - 1)1734 break;1735 len += sysfs_emit_at(buf, len, "%10lu",1736 df->freq_table[i]);1737 }1738 1739 if (len >= PAGE_SIZE - 1)1740 return PAGE_SIZE - 1;1741 len += sysfs_emit_at(buf, len, " time(ms)\n");1742 1743 for (i = 0; i < max_state; i++) {1744 if (len >= PAGE_SIZE - 1)1745 break;1746 if (df->freq_table[2] == df->previous_freq)1747 len += sysfs_emit_at(buf, len, "*");1748 else1749 len += sysfs_emit_at(buf, len, " ");1750 if (len >= PAGE_SIZE - 1)1751 break;1752 len += sysfs_emit_at(buf, len, "%10lu:", df->freq_table[i]);1753 for (j = 0; j < max_state; j++) {1754 if (len >= PAGE_SIZE - 1)1755 break;1756 len += sysfs_emit_at(buf, len, "%10u",1757 df->stats.trans_table[(i * max_state) + j]);1758 }1759 if (len >= PAGE_SIZE - 1)1760 break;1761 len += sysfs_emit_at(buf, len, "%10llu\n", (u64)1762 jiffies64_to_msecs(df->stats.time_in_state[i]));1763 }1764 1765 if (len < PAGE_SIZE - 1)1766 len += sysfs_emit_at(buf, len, "Total transition : %u\n",1767 df->stats.total_trans);1768 if (len >= PAGE_SIZE - 1) {1769 pr_warn_once("devfreq transition table exceeds PAGE_SIZE. Disabling\n");1770 return -EFBIG;1771 }1772 1773 return len;1774}1775 1776static ssize_t trans_stat_store(struct device *dev,1777 struct device_attribute *attr,1778 const char *buf, size_t count)1779{1780 struct devfreq *df = to_devfreq(dev);1781 int err, value;1782 1783 if (!df->profile)1784 return -EINVAL;1785 1786 if (df->max_state == 0)1787 return count;1788 1789 err = kstrtoint(buf, 10, &value);1790 if (err || value != 0)1791 return -EINVAL;1792 1793 mutex_lock(&df->lock);1794 memset(df->stats.time_in_state, 0, (df->max_state *1795 sizeof(*df->stats.time_in_state)));1796 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int),1797 df->max_state,1798 df->max_state));1799 df->stats.total_trans = 0;1800 df->stats.last_update = get_jiffies_64();1801 mutex_unlock(&df->lock);1802 1803 return count;1804}1805static DEVICE_ATTR_RW(trans_stat);1806 1807static struct attribute *devfreq_attrs[] = {1808 &dev_attr_name.attr,1809 &dev_attr_governor.attr,1810 &dev_attr_available_governors.attr,1811 &dev_attr_cur_freq.attr,1812 &dev_attr_available_frequencies.attr,1813 &dev_attr_target_freq.attr,1814 &dev_attr_min_freq.attr,1815 &dev_attr_max_freq.attr,1816 &dev_attr_trans_stat.attr,1817 NULL,1818};1819ATTRIBUTE_GROUPS(devfreq);1820 1821static ssize_t polling_interval_show(struct device *dev,1822 struct device_attribute *attr, char *buf)1823{1824 struct devfreq *df = to_devfreq(dev);1825 1826 if (!df->profile)1827 return -EINVAL;1828 1829 return sprintf(buf, "%d\n", df->profile->polling_ms);1830}1831 1832static ssize_t polling_interval_store(struct device *dev,1833 struct device_attribute *attr,1834 const char *buf, size_t count)1835{1836 struct devfreq *df = to_devfreq(dev);1837 unsigned int value;1838 int ret;1839 1840 if (!df->governor)1841 return -EINVAL;1842 1843 ret = sscanf(buf, "%u", &value);1844 if (ret != 1)1845 return -EINVAL;1846 1847 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value);1848 ret = count;1849 1850 return ret;1851}1852static DEVICE_ATTR_RW(polling_interval);1853 1854static ssize_t timer_show(struct device *dev,1855 struct device_attribute *attr, char *buf)1856{1857 struct devfreq *df = to_devfreq(dev);1858 1859 if (!df->profile)1860 return -EINVAL;1861 1862 return sprintf(buf, "%s\n", timer_name[df->profile->timer]);1863}1864 1865static ssize_t timer_store(struct device *dev, struct device_attribute *attr,1866 const char *buf, size_t count)1867{1868 struct devfreq *df = to_devfreq(dev);1869 char str_timer[DEVFREQ_NAME_LEN + 1];1870 int timer = -1;1871 int ret = 0, i;1872 1873 if (!df->governor || !df->profile)1874 return -EINVAL;1875 1876 ret = sscanf(buf, "%16s", str_timer);1877 if (ret != 1)1878 return -EINVAL;1879 1880 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) {1881 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) {1882 timer = i;1883 break;1884 }1885 }1886 1887 if (timer < 0) {1888 ret = -EINVAL;1889 goto out;1890 }1891 1892 if (df->profile->timer == timer) {1893 ret = 0;1894 goto out;1895 }1896 1897 mutex_lock(&df->lock);1898 df->profile->timer = timer;1899 mutex_unlock(&df->lock);1900 1901 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL);1902 if (ret) {1903 dev_warn(dev, "%s: Governor %s not stopped(%d)\n",1904 __func__, df->governor->name, ret);1905 goto out;1906 }1907 1908 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);1909 if (ret)1910 dev_warn(dev, "%s: Governor %s not started(%d)\n",1911 __func__, df->governor->name, ret);1912out:1913 return ret ? ret : count;1914}1915static DEVICE_ATTR_RW(timer);1916 1917#define CREATE_SYSFS_FILE(df, name) \1918{ \1919 int ret; \1920 ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \1921 if (ret < 0) { \1922 dev_warn(&df->dev, \1923 "Unable to create attr(%s)\n", "##name"); \1924 } \1925} \1926 1927/* Create the specific sysfs files which depend on each governor. */1928static void create_sysfs_files(struct devfreq *devfreq,1929 const struct devfreq_governor *gov)1930{1931 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))1932 CREATE_SYSFS_FILE(devfreq, polling_interval);1933 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))1934 CREATE_SYSFS_FILE(devfreq, timer);1935}1936 1937/* Remove the specific sysfs files which depend on each governor. */1938static void remove_sysfs_files(struct devfreq *devfreq,1939 const struct devfreq_governor *gov)1940{1941 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL))1942 sysfs_remove_file(&devfreq->dev.kobj,1943 &dev_attr_polling_interval.attr);1944 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER))1945 sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr);1946}1947 1948/**1949 * devfreq_summary_show() - Show the summary of the devfreq devices1950 * @s: seq_file instance to show the summary of devfreq devices1951 * @data: not used1952 *1953 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file.1954 * It helps that user can know the detailed information of the devfreq devices.1955 *1956 * Return 0 always because it shows the information without any data change.1957 */1958static int devfreq_summary_show(struct seq_file *s, void *data)1959{1960 struct devfreq *devfreq;1961 struct devfreq *p_devfreq = NULL;1962 unsigned long cur_freq, min_freq, max_freq;1963 unsigned int polling_ms;1964 unsigned int timer;1965 1966 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n",1967 "dev",1968 "parent_dev",1969 "governor",1970 "timer",1971 "polling_ms",1972 "cur_freq_Hz",1973 "min_freq_Hz",1974 "max_freq_Hz");1975 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n",1976 "------------------------------",1977 "------------------------------",1978 "---------------",1979 "----------",1980 "----------",1981 "------------",1982 "------------",1983 "------------");1984 1985 mutex_lock(&devfreq_list_lock);1986 1987 list_for_each_entry_reverse(devfreq, &devfreq_list, node) {1988#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)1989 if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE,1990 DEVFREQ_NAME_LEN)) {1991 struct devfreq_passive_data *data = devfreq->data;1992 1993 if (data)1994 p_devfreq = data->parent;1995 } else {1996 p_devfreq = NULL;1997 }1998#endif1999 2000 mutex_lock(&devfreq->lock);2001 cur_freq = devfreq->previous_freq;2002 devfreq_get_freq_range(devfreq, &min_freq, &max_freq);2003 timer = devfreq->profile->timer;2004 2005 if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL))2006 polling_ms = devfreq->profile->polling_ms;2007 else2008 polling_ms = 0;2009 mutex_unlock(&devfreq->lock);2010 2011 seq_printf(s,2012 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n",2013 dev_name(&devfreq->dev),2014 p_devfreq ? dev_name(&p_devfreq->dev) : "null",2015 devfreq->governor->name,2016 polling_ms ? timer_name[timer] : "null",2017 polling_ms,2018 cur_freq,2019 min_freq,2020 max_freq);2021 }2022 2023 mutex_unlock(&devfreq_list_lock);2024 2025 return 0;2026}2027DEFINE_SHOW_ATTRIBUTE(devfreq_summary);2028 2029static int __init devfreq_init(void)2030{2031 devfreq_class = class_create("devfreq");2032 if (IS_ERR(devfreq_class)) {2033 pr_err("%s: couldn't create class\n", __FILE__);2034 return PTR_ERR(devfreq_class);2035 }2036 2037 devfreq_wq = create_freezable_workqueue("devfreq_wq");2038 if (!devfreq_wq) {2039 class_destroy(devfreq_class);2040 pr_err("%s: couldn't create workqueue\n", __FILE__);2041 return -ENOMEM;2042 }2043 devfreq_class->dev_groups = devfreq_groups;2044 2045 devfreq_debugfs = debugfs_create_dir("devfreq", NULL);2046 debugfs_create_file("devfreq_summary", 0444,2047 devfreq_debugfs, NULL,2048 &devfreq_summary_fops);2049 2050 return 0;2051}2052subsys_initcall(devfreq_init);2053 2054/*2055 * The following are helper functions for devfreq user device drivers with2056 * OPP framework.2057 */2058 2059/**2060 * devfreq_recommended_opp() - Helper function to get proper OPP for the2061 * freq value given to target callback.2062 * @dev: The devfreq user device. (parent of devfreq)2063 * @freq: The frequency given to target function2064 * @flags: Flags handed from devfreq framework.2065 *2066 * The callers are required to call dev_pm_opp_put() for the returned OPP after2067 * use.2068 */2069struct dev_pm_opp *devfreq_recommended_opp(struct device *dev,2070 unsigned long *freq,2071 u32 flags)2072{2073 struct dev_pm_opp *opp;2074 2075 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) {2076 /* The freq is an upper bound. opp should be lower */2077 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);2078 2079 /* If not available, use the closest opp */2080 if (opp == ERR_PTR(-ERANGE))2081 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);2082 } else {2083 /* The freq is an lower bound. opp should be higher */2084 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0);2085 2086 /* If not available, use the closest opp */2087 if (opp == ERR_PTR(-ERANGE))2088 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0);2089 }2090 2091 return opp;2092}2093EXPORT_SYMBOL(devfreq_recommended_opp);2094 2095/**2096 * devfreq_register_opp_notifier() - Helper function to get devfreq notified2097 * for any changes in the OPP availability2098 * changes2099 * @dev: The devfreq user device. (parent of devfreq)2100 * @devfreq: The devfreq object.2101 */2102int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)2103{2104 return dev_pm_opp_register_notifier(dev, &devfreq->nb);2105}2106EXPORT_SYMBOL(devfreq_register_opp_notifier);2107 2108/**2109 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq2110 * notified for any changes in the OPP2111 * availability changes anymore.2112 * @dev: The devfreq user device. (parent of devfreq)2113 * @devfreq: The devfreq object.2114 *2115 * At exit() callback of devfreq_dev_profile, this must be included if2116 * devfreq_recommended_opp is used.2117 */2118int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)2119{2120 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb);2121}2122EXPORT_SYMBOL(devfreq_unregister_opp_notifier);2123 2124static void devm_devfreq_opp_release(struct device *dev, void *res)2125{2126 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res);2127}2128 2129/**2130 * devm_devfreq_register_opp_notifier() - Resource-managed2131 * devfreq_register_opp_notifier()2132 * @dev: The devfreq user device. (parent of devfreq)2133 * @devfreq: The devfreq object.2134 */2135int devm_devfreq_register_opp_notifier(struct device *dev,2136 struct devfreq *devfreq)2137{2138 struct devfreq **ptr;2139 int ret;2140 2141 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL);2142 if (!ptr)2143 return -ENOMEM;2144 2145 ret = devfreq_register_opp_notifier(dev, devfreq);2146 if (ret) {2147 devres_free(ptr);2148 return ret;2149 }2150 2151 *ptr = devfreq;2152 devres_add(dev, ptr);2153 2154 return 0;2155}2156EXPORT_SYMBOL(devm_devfreq_register_opp_notifier);2157 2158/**2159 * devm_devfreq_unregister_opp_notifier() - Resource-managed2160 * devfreq_unregister_opp_notifier()2161 * @dev: The devfreq user device. (parent of devfreq)2162 * @devfreq: The devfreq object.2163 */2164void devm_devfreq_unregister_opp_notifier(struct device *dev,2165 struct devfreq *devfreq)2166{2167 WARN_ON(devres_release(dev, devm_devfreq_opp_release,2168 devm_devfreq_dev_match, devfreq));2169}2170EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);2171 2172/**2173 * devfreq_register_notifier() - Register a driver with devfreq2174 * @devfreq: The devfreq object.2175 * @nb: The notifier block to register.2176 * @list: DEVFREQ_TRANSITION_NOTIFIER.2177 */2178int devfreq_register_notifier(struct devfreq *devfreq,2179 struct notifier_block *nb,2180 unsigned int list)2181{2182 int ret = 0;2183 2184 if (!devfreq)2185 return -EINVAL;2186 2187 switch (list) {2188 case DEVFREQ_TRANSITION_NOTIFIER:2189 ret = srcu_notifier_chain_register(2190 &devfreq->transition_notifier_list, nb);2191 break;2192 default:2193 ret = -EINVAL;2194 }2195 2196 return ret;2197}2198EXPORT_SYMBOL(devfreq_register_notifier);2199 2200/*2201 * devfreq_unregister_notifier() - Unregister a driver with devfreq2202 * @devfreq: The devfreq object.2203 * @nb: The notifier block to be unregistered.2204 * @list: DEVFREQ_TRANSITION_NOTIFIER.2205 */2206int devfreq_unregister_notifier(struct devfreq *devfreq,2207 struct notifier_block *nb,2208 unsigned int list)2209{2210 int ret = 0;2211 2212 if (!devfreq)2213 return -EINVAL;2214 2215 switch (list) {2216 case DEVFREQ_TRANSITION_NOTIFIER:2217 ret = srcu_notifier_chain_unregister(2218 &devfreq->transition_notifier_list, nb);2219 break;2220 default:2221 ret = -EINVAL;2222 }2223 2224 return ret;2225}2226EXPORT_SYMBOL(devfreq_unregister_notifier);2227 2228struct devfreq_notifier_devres {2229 struct devfreq *devfreq;2230 struct notifier_block *nb;2231 unsigned int list;2232};2233 2234static void devm_devfreq_notifier_release(struct device *dev, void *res)2235{2236 struct devfreq_notifier_devres *this = res;2237 2238 devfreq_unregister_notifier(this->devfreq, this->nb, this->list);2239}2240 2241/**2242 * devm_devfreq_register_notifier()2243 * - Resource-managed devfreq_register_notifier()2244 * @dev: The devfreq user device. (parent of devfreq)2245 * @devfreq: The devfreq object.2246 * @nb: The notifier block to be unregistered.2247 * @list: DEVFREQ_TRANSITION_NOTIFIER.2248 */2249int devm_devfreq_register_notifier(struct device *dev,2250 struct devfreq *devfreq,2251 struct notifier_block *nb,2252 unsigned int list)2253{2254 struct devfreq_notifier_devres *ptr;2255 int ret;2256 2257 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),2258 GFP_KERNEL);2259 if (!ptr)2260 return -ENOMEM;2261 2262 ret = devfreq_register_notifier(devfreq, nb, list);2263 if (ret) {2264 devres_free(ptr);2265 return ret;2266 }2267 2268 ptr->devfreq = devfreq;2269 ptr->nb = nb;2270 ptr->list = list;2271 devres_add(dev, ptr);2272 2273 return 0;2274}2275EXPORT_SYMBOL(devm_devfreq_register_notifier);2276 2277/**2278 * devm_devfreq_unregister_notifier()2279 * - Resource-managed devfreq_unregister_notifier()2280 * @dev: The devfreq user device. (parent of devfreq)2281 * @devfreq: The devfreq object.2282 * @nb: The notifier block to be unregistered.2283 * @list: DEVFREQ_TRANSITION_NOTIFIER.2284 */2285void devm_devfreq_unregister_notifier(struct device *dev,2286 struct devfreq *devfreq,2287 struct notifier_block *nb,2288 unsigned int list)2289{2290 WARN_ON(devres_release(dev, devm_devfreq_notifier_release,2291 devm_devfreq_dev_match, devfreq));2292}2293EXPORT_SYMBOL(devm_devfreq_unregister_notifier);2294