1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework 4 * for Non-CPU Devices. 5 * 6 * Copyright (C) 2011 Samsung Electronics 7 * MyungJoo Ham <myungjoo.ham@samsung.com> 8 */ 9 10#include <linux/kernel.h> 11#include <linux/kmod.h> 12#include <linux/sched.h> 13#include <linux/debugfs.h> 14#include <linux/errno.h> 15#include <linux/err.h> 16#include <linux/init.h> 17#include <linux/export.h> 18#include <linux/slab.h> 19#include <linux/stat.h> 20#include <linux/pm_opp.h> 21#include <linux/devfreq.h> 22#include <linux/workqueue.h> 23#include <linux/platform_device.h> 24#include <linux/list.h> 25#include <linux/printk.h> 26#include <linux/hrtimer.h> 27#include <linux/of.h> 28#include <linux/pm_qos.h> 29#include "governor.h" 30 31#define CREATE_TRACE_POINTS 32#include <trace/events/devfreq.h> 33 34#define HZ_PER_KHZ 1000 35 36static struct class *devfreq_class; 37static struct dentry *devfreq_debugfs; 38 39/* 40 * devfreq core provides delayed work based load monitoring helper 41 * functions. Governors can use these or can implement their own 42 * monitoring mechanism. 43 */ 44static struct workqueue_struct *devfreq_wq; 45 46/* The list of all device-devfreq governors */ 47static LIST_HEAD(devfreq_governor_list); 48/* The list of all device-devfreq */ 49static LIST_HEAD(devfreq_list); 50static DEFINE_MUTEX(devfreq_list_lock); 51 52static const char timer_name[][DEVFREQ_NAME_LEN] = { 53 [DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" }, 54 [DEVFREQ_TIMER_DELAYED] = { "delayed" }, 55}; 56 57/** 58 * find_device_devfreq() - find devfreq struct using device pointer 59 * @dev: device pointer used to lookup device devfreq. 60 * 61 * Search the list of device devfreqs and return the matched device's 62 * devfreq info. devfreq_list_lock should be held by the caller. 63 */ 64static struct devfreq *find_device_devfreq(struct device *dev) 65{ 66 struct devfreq *tmp_devfreq; 67 68 lockdep_assert_held(&devfreq_list_lock); 69 70 if (IS_ERR_OR_NULL(dev)) { 71 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); 72 return ERR_PTR(-EINVAL); 73 } 74 75 list_for_each_entry(tmp_devfreq, &devfreq_list, node) { 76 if (tmp_devfreq->dev.parent == dev) 77 return tmp_devfreq; 78 } 79 80 return ERR_PTR(-ENODEV); 81} 82 83static unsigned long find_available_min_freq(struct devfreq *devfreq) 84{ 85 struct dev_pm_opp *opp; 86 unsigned long min_freq = 0; 87 88 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &min_freq); 89 if (IS_ERR(opp)) 90 min_freq = 0; 91 else 92 dev_pm_opp_put(opp); 93 94 return min_freq; 95} 96 97static unsigned long find_available_max_freq(struct devfreq *devfreq) 98{ 99 struct dev_pm_opp *opp; 100 unsigned long max_freq = ULONG_MAX; 101 102 opp = dev_pm_opp_find_freq_floor(devfreq->dev.parent, &max_freq); 103 if (IS_ERR(opp)) 104 max_freq = 0; 105 else 106 dev_pm_opp_put(opp); 107 108 return max_freq; 109} 110 111/** 112 * get_freq_range() - Get the current freq range 113 * @devfreq: the devfreq instance 114 * @min_freq: the min frequency 115 * @max_freq: the max frequency 116 * 117 * This takes into consideration all constraints. 118 */ 119static void get_freq_range(struct devfreq *devfreq, 120 unsigned long *min_freq, 121 unsigned long *max_freq) 122{ 123 unsigned long *freq_table = devfreq->profile->freq_table; 124 s32 qos_min_freq, qos_max_freq; 125 126 lockdep_assert_held(&devfreq->lock); 127 128 /* 129 * Initialize minimum/maximum frequency from freq table. 130 * The devfreq drivers can initialize this in either ascending or 131 * descending order and devfreq core supports both. 132 */ 133 if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { 134 *min_freq = freq_table[0]; 135 *max_freq = freq_table[devfreq->profile->max_state - 1]; 136 } else { 137 *min_freq = freq_table[devfreq->profile->max_state - 1]; 138 *max_freq = freq_table[0]; 139 } 140 141 /* Apply constraints from PM QoS */ 142 qos_min_freq = dev_pm_qos_read_value(devfreq->dev.parent, 143 DEV_PM_QOS_MIN_FREQUENCY); 144 qos_max_freq = dev_pm_qos_read_value(devfreq->dev.parent, 145 DEV_PM_QOS_MAX_FREQUENCY); 146 *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq); 147 if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE) 148 *max_freq = min(*max_freq, 149 (unsigned long)HZ_PER_KHZ * qos_max_freq); 150 151 /* Apply constraints from OPP interface */ 152 *min_freq = max(*min_freq, devfreq->scaling_min_freq); 153 *max_freq = min(*max_freq, devfreq->scaling_max_freq); 154 155 if (*min_freq > *max_freq) 156 *min_freq = *max_freq; 157} 158 159/** 160 * devfreq_get_freq_level() - Lookup freq_table for the frequency 161 * @devfreq: the devfreq instance 162 * @freq: the target frequency 163 */ 164static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq) 165{ 166 int lev; 167 168 for (lev = 0; lev < devfreq->profile->max_state; lev++) 169 if (freq == devfreq->profile->freq_table[lev]) 170 return lev; 171 172 return -EINVAL; 173} 174 175static int set_freq_table(struct devfreq *devfreq) 176{ 177 struct devfreq_dev_profile *profile = devfreq->profile; 178 struct dev_pm_opp *opp; 179 unsigned long freq; 180 int i, count; 181 182 /* Initialize the freq_table from OPP table */ 183 count = dev_pm_opp_get_opp_count(devfreq->dev.parent); 184 if (count <= 0) 185 return -EINVAL; 186 187 profile->max_state = count; 188 profile->freq_table = devm_kcalloc(devfreq->dev.parent, 189 profile->max_state, 190 sizeof(*profile->freq_table), 191 GFP_KERNEL); 192 if (!profile->freq_table) { 193 profile->max_state = 0; 194 return -ENOMEM; 195 } 196 197 for (i = 0, freq = 0; i < profile->max_state; i++, freq++) { 198 opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq); 199 if (IS_ERR(opp)) { 200 devm_kfree(devfreq->dev.parent, profile->freq_table); 201 profile->max_state = 0; 202 return PTR_ERR(opp); 203 } 204 dev_pm_opp_put(opp); 205 profile->freq_table[i] = freq; 206 } 207 208 return 0; 209} 210 211/** 212 * devfreq_update_status() - Update statistics of devfreq behavior 213 * @devfreq: the devfreq instance 214 * @freq: the update target frequency 215 */ 216int devfreq_update_status(struct devfreq *devfreq, unsigned long freq) 217{ 218 int lev, prev_lev, ret = 0; 219 u64 cur_time; 220 221 lockdep_assert_held(&devfreq->lock); 222 cur_time = get_jiffies_64(); 223 224 /* Immediately exit if previous_freq is not initialized yet. */ 225 if (!devfreq->previous_freq) 226 goto out; 227 228 prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq); 229 if (prev_lev < 0) { 230 ret = prev_lev; 231 goto out; 232 } 233 234 devfreq->stats.time_in_state[prev_lev] += 235 cur_time - devfreq->stats.last_update; 236 237 lev = devfreq_get_freq_level(devfreq, freq); 238 if (lev < 0) { 239 ret = lev; 240 goto out; 241 } 242 243 if (lev != prev_lev) { 244 devfreq->stats.trans_table[ 245 (prev_lev * devfreq->profile->max_state) + lev]++; 246 devfreq->stats.total_trans++; 247 } 248 249out: 250 devfreq->stats.last_update = cur_time; 251 return ret; 252} 253EXPORT_SYMBOL(devfreq_update_status); 254 255/** 256 * find_devfreq_governor() - find devfreq governor from name 257 * @name: name of the governor 258 * 259 * Search the list of devfreq governors and return the matched 260 * governor's pointer. devfreq_list_lock should be held by the caller. 261 */ 262static struct devfreq_governor *find_devfreq_governor(const char *name) 263{ 264 struct devfreq_governor *tmp_governor; 265 266 lockdep_assert_held(&devfreq_list_lock); 267 268 if (IS_ERR_OR_NULL(name)) { 269 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); 270 return ERR_PTR(-EINVAL); 271 } 272 273 list_for_each_entry(tmp_governor, &devfreq_governor_list, node) { 274 if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN)) 275 return tmp_governor; 276 } 277 278 return ERR_PTR(-ENODEV); 279} 280 281/** 282 * try_then_request_governor() - Try to find the governor and request the 283 * module if is not found. 284 * @name: name of the governor 285 * 286 * Search the list of devfreq governors and request the module and try again 287 * if is not found. This can happen when both drivers (the governor driver 288 * and the driver that call devfreq_add_device) are built as modules. 289 * devfreq_list_lock should be held by the caller. Returns the matched 290 * governor's pointer or an error pointer. 291 */ 292static struct devfreq_governor *try_then_request_governor(const char *name) 293{ 294 struct devfreq_governor *governor; 295 int err = 0; 296 297 lockdep_assert_held(&devfreq_list_lock); 298 299 if (IS_ERR_OR_NULL(name)) { 300 pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); 301 return ERR_PTR(-EINVAL); 302 } 303 304 governor = find_devfreq_governor(name); 305 if (IS_ERR(governor)) { 306 mutex_unlock(&devfreq_list_lock); 307 308 if (!strncmp(name, DEVFREQ_GOV_SIMPLE_ONDEMAND, 309 DEVFREQ_NAME_LEN)) 310 err = request_module("governor_%s", "simpleondemand"); 311 else 312 err = request_module("governor_%s", name); 313 /* Restore previous state before return */ 314 mutex_lock(&devfreq_list_lock); 315 if (err) 316 return (err < 0) ? ERR_PTR(err) : ERR_PTR(-EINVAL); 317 318 governor = find_devfreq_governor(name); 319 } 320 321 return governor; 322} 323 324static int devfreq_notify_transition(struct devfreq *devfreq, 325 struct devfreq_freqs *freqs, unsigned int state) 326{ 327 if (!devfreq) 328 return -EINVAL; 329 330 switch (state) { 331 case DEVFREQ_PRECHANGE: 332 srcu_notifier_call_chain(&devfreq->transition_notifier_list, 333 DEVFREQ_PRECHANGE, freqs); 334 break; 335 336 case DEVFREQ_POSTCHANGE: 337 srcu_notifier_call_chain(&devfreq->transition_notifier_list, 338 DEVFREQ_POSTCHANGE, freqs); 339 break; 340 default: 341 return -EINVAL; 342 } 343 344 return 0; 345} 346 347static int devfreq_set_target(struct devfreq *devfreq, unsigned long new_freq, 348 u32 flags) 349{ 350 struct devfreq_freqs freqs; 351 unsigned long cur_freq; 352 int err = 0; 353 354 if (devfreq->profile->get_cur_freq) 355 devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq); 356 else 357 cur_freq = devfreq->previous_freq; 358 359 freqs.old = cur_freq; 360 freqs.new = new_freq; 361 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE); 362 363 err = devfreq->profile->target(devfreq->dev.parent, &new_freq, flags); 364 if (err) { 365 freqs.new = cur_freq; 366 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); 367 return err; 368 } 369 370 freqs.new = new_freq; 371 devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE); 372 373 if (devfreq_update_status(devfreq, new_freq)) 374 dev_err(&devfreq->dev, 375 "Couldn't update frequency transition information.\n"); 376 377 devfreq->previous_freq = new_freq; 378 379 if (devfreq->suspend_freq) 380 devfreq->resume_freq = new_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 if (devfreq->stop_polling) 442 goto out; 443 444 queue_delayed_work(devfreq_wq, &devfreq->work, 445 msecs_to_jiffies(devfreq->profile->polling_ms)); 446 447out: 448 mutex_unlock(&devfreq->lock); 449 trace_devfreq_monitor(devfreq); 450} 451 452/** 453 * devfreq_monitor_start() - Start load monitoring of devfreq instance 454 * @devfreq: the devfreq instance. 455 * 456 * Helper function for starting devfreq device load monitoring. By 457 * default delayed work based monitoring is supported. Function 458 * to be called from governor in response to DEVFREQ_GOV_START 459 * event when device is added to devfreq framework. 460 */ 461void devfreq_monitor_start(struct devfreq *devfreq) 462{ 463 if (devfreq->governor->interrupt_driven) 464 return; 465 466 mutex_lock(&devfreq->lock); 467 if (delayed_work_pending(&devfreq->work)) 468 goto out; 469 470 switch (devfreq->profile->timer) { 471 case DEVFREQ_TIMER_DEFERRABLE: 472 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); 473 break; 474 case DEVFREQ_TIMER_DELAYED: 475 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor); 476 break; 477 default: 478 goto out; 479 } 480 481 if (devfreq->profile->polling_ms) 482 queue_delayed_work(devfreq_wq, &devfreq->work, 483 msecs_to_jiffies(devfreq->profile->polling_ms)); 484 485out: 486 devfreq->stop_polling = false; 487 mutex_unlock(&devfreq->lock); 488} 489EXPORT_SYMBOL(devfreq_monitor_start); 490 491/** 492 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance 493 * @devfreq: the devfreq instance. 494 * 495 * Helper function to stop devfreq device load monitoring. Function 496 * to be called from governor in response to DEVFREQ_GOV_STOP 497 * event when device is removed from devfreq framework. 498 */ 499void devfreq_monitor_stop(struct devfreq *devfreq) 500{ 501 if (devfreq->governor->interrupt_driven) 502 return; 503 504 mutex_lock(&devfreq->lock); 505 if (devfreq->stop_polling) { 506 mutex_unlock(&devfreq->lock); 507 return; 508 } 509 510 devfreq->stop_polling = true; 511 mutex_unlock(&devfreq->lock); 512 cancel_delayed_work_sync(&devfreq->work); 513} 514EXPORT_SYMBOL(devfreq_monitor_stop); 515 516/** 517 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance 518 * @devfreq: the devfreq instance. 519 * 520 * Helper function to suspend devfreq device load monitoring. Function 521 * to be called from governor in response to DEVFREQ_GOV_SUSPEND 522 * event or when polling interval is set to zero. 523 * 524 * Note: Though this function is same as devfreq_monitor_stop(), 525 * intentionally kept separate to provide hooks for collecting 526 * transition statistics. 527 */ 528void devfreq_monitor_suspend(struct devfreq *devfreq) 529{ 530 mutex_lock(&devfreq->lock); 531 if (devfreq->stop_polling) { 532 mutex_unlock(&devfreq->lock); 533 return; 534 } 535 536 devfreq_update_status(devfreq, devfreq->previous_freq); 537 devfreq->stop_polling = true; 538 mutex_unlock(&devfreq->lock); 539 540 if (devfreq->governor->interrupt_driven) 541 return; 542 543 cancel_delayed_work_sync(&devfreq->work); 544} 545EXPORT_SYMBOL(devfreq_monitor_suspend); 546 547/** 548 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance 549 * @devfreq: the devfreq instance. 550 * 551 * Helper function to resume devfreq device load monitoring. Function 552 * to be called from governor in response to DEVFREQ_GOV_RESUME 553 * event or when polling interval is set to non-zero. 554 */ 555void devfreq_monitor_resume(struct devfreq *devfreq) 556{ 557 unsigned long freq; 558 559 mutex_lock(&devfreq->lock); 560 if (!devfreq->stop_polling) 561 goto out; 562 563 if (devfreq->governor->interrupt_driven) 564 goto out_update; 565 566 if (!delayed_work_pending(&devfreq->work) && 567 devfreq->profile->polling_ms) 568 queue_delayed_work(devfreq_wq, &devfreq->work, 569 msecs_to_jiffies(devfreq->profile->polling_ms)); 570 571out_update: 572 devfreq->stats.last_update = get_jiffies_64(); 573 devfreq->stop_polling = false; 574 575 if (devfreq->profile->get_cur_freq && 576 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) 577 devfreq->previous_freq = freq; 578 579out: 580 mutex_unlock(&devfreq->lock); 581} 582EXPORT_SYMBOL(devfreq_monitor_resume); 583 584/** 585 * devfreq_update_interval() - Update device devfreq monitoring interval 586 * @devfreq: the devfreq instance. 587 * @delay: new polling interval to be set. 588 * 589 * Helper function to set new load monitoring polling interval. Function 590 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event. 591 */ 592void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay) 593{ 594 unsigned int cur_delay = devfreq->profile->polling_ms; 595 unsigned int new_delay = *delay; 596 597 mutex_lock(&devfreq->lock); 598 devfreq->profile->polling_ms = new_delay; 599 600 if (devfreq->stop_polling) 601 goto out; 602 603 if (devfreq->governor->interrupt_driven) 604 goto out; 605 606 /* if new delay is zero, stop polling */ 607 if (!new_delay) { 608 mutex_unlock(&devfreq->lock); 609 cancel_delayed_work_sync(&devfreq->work); 610 return; 611 } 612 613 /* if current delay is zero, start polling with new delay */ 614 if (!cur_delay) { 615 queue_delayed_work(devfreq_wq, &devfreq->work, 616 msecs_to_jiffies(devfreq->profile->polling_ms)); 617 goto out; 618 } 619 620 /* if current delay is greater than new delay, restart polling */ 621 if (cur_delay > new_delay) { 622 mutex_unlock(&devfreq->lock); 623 cancel_delayed_work_sync(&devfreq->work); 624 mutex_lock(&devfreq->lock); 625 if (!devfreq->stop_polling) 626 queue_delayed_work(devfreq_wq, &devfreq->work, 627 msecs_to_jiffies(devfreq->profile->polling_ms)); 628 } 629out: 630 mutex_unlock(&devfreq->lock); 631} 632EXPORT_SYMBOL(devfreq_update_interval); 633 634/** 635 * devfreq_notifier_call() - Notify that the device frequency requirements 636 * has been changed out of devfreq framework. 637 * @nb: the notifier_block (supposed to be devfreq->nb) 638 * @type: not used 639 * @devp: not used 640 * 641 * Called by a notifier that uses devfreq->nb. 642 */ 643static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, 644 void *devp) 645{ 646 struct devfreq *devfreq = container_of(nb, struct devfreq, nb); 647 int err = -EINVAL; 648 649 mutex_lock(&devfreq->lock); 650 651 devfreq->scaling_min_freq = find_available_min_freq(devfreq); 652 if (!devfreq->scaling_min_freq) 653 goto out; 654 655 devfreq->scaling_max_freq = find_available_max_freq(devfreq); 656 if (!devfreq->scaling_max_freq) { 657 devfreq->scaling_max_freq = ULONG_MAX; 658 goto out; 659 } 660 661 err = update_devfreq(devfreq); 662 663out: 664 mutex_unlock(&devfreq->lock); 665 if (err) 666 dev_err(devfreq->dev.parent, 667 "failed to update frequency from OPP notifier (%d)\n", 668 err); 669 670 return NOTIFY_OK; 671} 672 673/** 674 * qos_notifier_call() - Common handler for QoS constraints. 675 * @devfreq: the devfreq instance. 676 */ 677static int qos_notifier_call(struct devfreq *devfreq) 678{ 679 int err; 680 681 mutex_lock(&devfreq->lock); 682 err = update_devfreq(devfreq); 683 mutex_unlock(&devfreq->lock); 684 if (err) 685 dev_err(devfreq->dev.parent, 686 "failed to update frequency from PM QoS (%d)\n", 687 err); 688 689 return NOTIFY_OK; 690} 691 692/** 693 * qos_min_notifier_call() - Callback for QoS min_freq changes. 694 * @nb: Should be devfreq->nb_min 695 */ 696static int qos_min_notifier_call(struct notifier_block *nb, 697 unsigned long val, void *ptr) 698{ 699 return qos_notifier_call(container_of(nb, struct devfreq, nb_min)); 700} 701 702/** 703 * qos_max_notifier_call() - Callback for QoS max_freq changes. 704 * @nb: Should be devfreq->nb_max 705 */ 706static int qos_max_notifier_call(struct notifier_block *nb, 707 unsigned long val, void *ptr) 708{ 709 return qos_notifier_call(container_of(nb, struct devfreq, nb_max)); 710} 711 712/** 713 * devfreq_dev_release() - Callback for struct device to release the device. 714 * @dev: the devfreq device 715 * 716 * Remove devfreq from the list and release its resources. 717 */ 718static void devfreq_dev_release(struct device *dev) 719{ 720 struct devfreq *devfreq = to_devfreq(dev); 721 int err; 722 723 mutex_lock(&devfreq_list_lock); 724 list_del(&devfreq->node); 725 mutex_unlock(&devfreq_list_lock); 726 727 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max, 728 DEV_PM_QOS_MAX_FREQUENCY); 729 if (err && err != -ENOENT) 730 dev_warn(dev->parent, 731 "Failed to remove max_freq notifier: %d\n", err); 732 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min, 733 DEV_PM_QOS_MIN_FREQUENCY); 734 if (err && err != -ENOENT) 735 dev_warn(dev->parent, 736 "Failed to remove min_freq notifier: %d\n", err); 737 738 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { 739 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); 740 if (err < 0) 741 dev_warn(dev->parent, 742 "Failed to remove max_freq request: %d\n", err); 743 } 744 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { 745 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); 746 if (err < 0) 747 dev_warn(dev->parent, 748 "Failed to remove min_freq request: %d\n", err); 749 } 750 751 if (devfreq->profile->exit) 752 devfreq->profile->exit(devfreq->dev.parent); 753 754 mutex_destroy(&devfreq->lock); 755 srcu_cleanup_notifier_head(&devfreq->transition_notifier_list); 756 kfree(devfreq); 757} 758 759/** 760 * devfreq_add_device() - Add devfreq feature to the device 761 * @dev: the device to add devfreq feature. 762 * @profile: device-specific profile to run devfreq. 763 * @governor_name: name of the policy to choose frequency. 764 * @data: devfreq driver pass to governors, governor should not change it. 765 */ 766struct devfreq *devfreq_add_device(struct device *dev, 767 struct devfreq_dev_profile *profile, 768 const char *governor_name, 769 void *data) 770{ 771 struct devfreq *devfreq; 772 struct devfreq_governor *governor; 773 int err = 0; 774 775 if (!dev || !profile || !governor_name) { 776 dev_err(dev, "%s: Invalid parameters.\n", __func__); 777 return ERR_PTR(-EINVAL); 778 } 779 780 mutex_lock(&devfreq_list_lock); 781 devfreq = find_device_devfreq(dev); 782 mutex_unlock(&devfreq_list_lock); 783 if (!IS_ERR(devfreq)) { 784 dev_err(dev, "%s: devfreq device already exists!\n", 785 __func__); 786 err = -EINVAL; 787 goto err_out; 788 } 789 790 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); 791 if (!devfreq) { 792 err = -ENOMEM; 793 goto err_out; 794 } 795 796 mutex_init(&devfreq->lock); 797 mutex_lock(&devfreq->lock); 798 devfreq->dev.parent = dev; 799 devfreq->dev.class = devfreq_class; 800 devfreq->dev.release = devfreq_dev_release; 801 INIT_LIST_HEAD(&devfreq->node); 802 devfreq->profile = profile; 803 strscpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); 804 devfreq->previous_freq = profile->initial_freq; 805 devfreq->last_status.current_frequency = profile->initial_freq; 806 devfreq->data = data; 807 devfreq->nb.notifier_call = devfreq_notifier_call; 808 809 if (devfreq->profile->timer < 0 810 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) { 811 mutex_unlock(&devfreq->lock); 812 err = -EINVAL; 813 goto err_dev; 814 } 815 816 if (!devfreq->profile->max_state && !devfreq->profile->freq_table) { 817 mutex_unlock(&devfreq->lock); 818 err = set_freq_table(devfreq); 819 if (err < 0) 820 goto err_dev; 821 mutex_lock(&devfreq->lock); 822 } 823 824 devfreq->scaling_min_freq = find_available_min_freq(devfreq); 825 if (!devfreq->scaling_min_freq) { 826 mutex_unlock(&devfreq->lock); 827 err = -EINVAL; 828 goto err_dev; 829 } 830 831 devfreq->scaling_max_freq = find_available_max_freq(devfreq); 832 if (!devfreq->scaling_max_freq) { 833 mutex_unlock(&devfreq->lock); 834 err = -EINVAL; 835 goto err_dev; 836 } 837 838 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); 839 atomic_set(&devfreq->suspend_count, 0); 840 841 dev_set_name(&devfreq->dev, "%s", dev_name(dev)); 842 err = device_register(&devfreq->dev); 843 if (err) { 844 mutex_unlock(&devfreq->lock); 845 put_device(&devfreq->dev); 846 goto err_out; 847 } 848 849 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev, 850 array3_size(sizeof(unsigned int), 851 devfreq->profile->max_state, 852 devfreq->profile->max_state), 853 GFP_KERNEL); 854 if (!devfreq->stats.trans_table) { 855 mutex_unlock(&devfreq->lock); 856 err = -ENOMEM; 857 goto err_devfreq; 858 } 859 860 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev, 861 devfreq->profile->max_state, 862 sizeof(*devfreq->stats.time_in_state), 863 GFP_KERNEL); 864 if (!devfreq->stats.time_in_state) { 865 mutex_unlock(&devfreq->lock); 866 err = -ENOMEM; 867 goto err_devfreq; 868 } 869 870 devfreq->stats.total_trans = 0; 871 devfreq->stats.last_update = get_jiffies_64(); 872 873 srcu_init_notifier_head(&devfreq->transition_notifier_list); 874 875 mutex_unlock(&devfreq->lock); 876 877 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, 878 DEV_PM_QOS_MIN_FREQUENCY, 0); 879 if (err < 0) 880 goto err_devfreq; 881 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, 882 DEV_PM_QOS_MAX_FREQUENCY, 883 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); 884 if (err < 0) 885 goto err_devfreq; 886 887 devfreq->nb_min.notifier_call = qos_min_notifier_call; 888 err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, 889 DEV_PM_QOS_MIN_FREQUENCY); 890 if (err) 891 goto err_devfreq; 892 893 devfreq->nb_max.notifier_call = qos_max_notifier_call; 894 err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_max, 895 DEV_PM_QOS_MAX_FREQUENCY); 896 if (err) 897 goto err_devfreq; 898 899 mutex_lock(&devfreq_list_lock); 900 901 governor = try_then_request_governor(devfreq->governor_name); 902 if (IS_ERR(governor)) { 903 dev_err(dev, "%s: Unable to find governor for the device\n", 904 __func__); 905 err = PTR_ERR(governor); 906 goto err_init; 907 } 908 909 devfreq->governor = governor; 910 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START, 911 NULL); 912 if (err) { 913 dev_err(dev, "%s: Unable to start governor for the device\n", 914 __func__); 915 goto err_init; 916 } 917 918 list_add(&devfreq->node, &devfreq_list); 919 920 mutex_unlock(&devfreq_list_lock); 921 922 return devfreq; 923 924err_init: 925 mutex_unlock(&devfreq_list_lock); 926err_devfreq: 927 devfreq_remove_device(devfreq); 928 devfreq = NULL; 929err_dev: 930 kfree(devfreq); 931err_out: 932 return ERR_PTR(err); 933} 934EXPORT_SYMBOL(devfreq_add_device); 935 936/** 937 * devfreq_remove_device() - Remove devfreq feature from a device. 938 * @devfreq: the devfreq instance to be removed 939 * 940 * The opposite of devfreq_add_device(). 941 */ 942int devfreq_remove_device(struct devfreq *devfreq) 943{ 944 if (!devfreq) 945 return -EINVAL; 946 947 if (devfreq->governor) 948 devfreq->governor->event_handler(devfreq, 949 DEVFREQ_GOV_STOP, NULL); 950 device_unregister(&devfreq->dev); 951 952 return 0; 953} 954EXPORT_SYMBOL(devfreq_remove_device); 955 956static int devm_devfreq_dev_match(struct device *dev, void *res, void *data) 957{ 958 struct devfreq **r = res; 959 960 if (WARN_ON(!r || !*r)) 961 return 0; 962 963 return *r == data; 964} 965 966static void devm_devfreq_dev_release(struct device *dev, void *res) 967{ 968 devfreq_remove_device(*(struct devfreq **)res); 969} 970 971/** 972 * devm_devfreq_add_device() - Resource-managed devfreq_add_device() 973 * @dev: the device to add devfreq feature. 974 * @profile: device-specific profile to run devfreq. 975 * @governor_name: name of the policy to choose frequency. 976 * @data: devfreq driver pass to governors, governor should not change it. 977 * 978 * This function manages automatically the memory of devfreq device using device 979 * resource management and simplify the free operation for memory of devfreq 980 * device. 981 */ 982struct devfreq *devm_devfreq_add_device(struct device *dev, 983 struct devfreq_dev_profile *profile, 984 const char *governor_name, 985 void *data) 986{ 987 struct devfreq **ptr, *devfreq; 988 989 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL); 990 if (!ptr) 991 return ERR_PTR(-ENOMEM); 992 993 devfreq = devfreq_add_device(dev, profile, governor_name, data); 994 if (IS_ERR(devfreq)) { 995 devres_free(ptr); 996 return devfreq; 997 } 998 999 *ptr = devfreq; 1000 devres_add(dev, ptr); 1001 1002 return devfreq; 1003} 1004EXPORT_SYMBOL(devm_devfreq_add_device); 1005 1006#ifdef CONFIG_OF 1007/* 1008 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree 1009 * @node - pointer to device_node 1010 * 1011 * return the instance of devfreq device 1012 */ 1013struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 1014{ 1015 struct devfreq *devfreq; 1016 1017 if (!node) 1018 return ERR_PTR(-EINVAL); 1019 1020 mutex_lock(&devfreq_list_lock); 1021 list_for_each_entry(devfreq, &devfreq_list, node) { 1022 if (devfreq->dev.parent 1023 && devfreq->dev.parent->of_node == node) { 1024 mutex_unlock(&devfreq_list_lock); 1025 return devfreq; 1026 } 1027 } 1028 mutex_unlock(&devfreq_list_lock); 1029 1030 return ERR_PTR(-ENODEV); 1031} 1032 1033/* 1034 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree 1035 * @dev - instance to the given device 1036 * @phandle_name - name of property holding a phandle value 1037 * @index - index into list of devfreq 1038 * 1039 * return the instance of devfreq device 1040 */ 1041struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 1042 const char *phandle_name, int index) 1043{ 1044 struct device_node *node; 1045 struct devfreq *devfreq; 1046 1047 if (!dev || !phandle_name) 1048 return ERR_PTR(-EINVAL); 1049 1050 if (!dev->of_node) 1051 return ERR_PTR(-EINVAL); 1052 1053 node = of_parse_phandle(dev->of_node, phandle_name, index); 1054 if (!node) 1055 return ERR_PTR(-ENODEV); 1056 1057 devfreq = devfreq_get_devfreq_by_node(node); 1058 of_node_put(node); 1059 1060 return devfreq; 1061} 1062 1063#else 1064struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 1065{ 1066 return ERR_PTR(-ENODEV); 1067} 1068 1069struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 1070 const char *phandle_name, int index) 1071{ 1072 return ERR_PTR(-ENODEV); 1073} 1074#endif /* CONFIG_OF */ 1075EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node); 1076EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle); 1077 1078/** 1079 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device() 1080 * @dev: the device from which to remove devfreq feature. 1081 * @devfreq: the devfreq instance to be removed 1082 */ 1083void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq) 1084{ 1085 WARN_ON(devres_release(dev, devm_devfreq_dev_release, 1086 devm_devfreq_dev_match, devfreq)); 1087} 1088EXPORT_SYMBOL(devm_devfreq_remove_device); 1089 1090/** 1091 * devfreq_suspend_device() - Suspend devfreq of a device. 1092 * @devfreq: the devfreq instance to be suspended 1093 * 1094 * This function is intended to be called by the pm callbacks 1095 * (e.g., runtime_suspend, suspend) of the device driver that 1096 * holds the devfreq. 1097 */ 1098int devfreq_suspend_device(struct devfreq *devfreq) 1099{ 1100 int ret; 1101 1102 if (!devfreq) 1103 return -EINVAL; 1104 1105 if (atomic_inc_return(&devfreq->suspend_count) > 1) 1106 return 0; 1107 1108 if (devfreq->governor) { 1109 ret = devfreq->governor->event_handler(devfreq, 1110 DEVFREQ_GOV_SUSPEND, NULL); 1111 if (ret) 1112 return ret; 1113 } 1114 1115 if (devfreq->suspend_freq) { 1116 mutex_lock(&devfreq->lock); 1117 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0); 1118 mutex_unlock(&devfreq->lock); 1119 if (ret) 1120 return ret; 1121 } 1122 1123 return 0; 1124} 1125EXPORT_SYMBOL(devfreq_suspend_device); 1126 1127/** 1128 * devfreq_resume_device() - Resume devfreq of a device. 1129 * @devfreq: the devfreq instance to be resumed 1130 * 1131 * This function is intended to be called by the pm callbacks 1132 * (e.g., runtime_resume, resume) of the device driver that 1133 * holds the devfreq. 1134 */ 1135int devfreq_resume_device(struct devfreq *devfreq) 1136{ 1137 int ret; 1138 1139 if (!devfreq) 1140 return -EINVAL; 1141 1142 if (atomic_dec_return(&devfreq->suspend_count) >= 1) 1143 return 0; 1144 1145 if (devfreq->resume_freq) { 1146 mutex_lock(&devfreq->lock); 1147 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0); 1148 mutex_unlock(&devfreq->lock); 1149 if (ret) 1150 return ret; 1151 } 1152 1153 if (devfreq->governor) { 1154 ret = devfreq->governor->event_handler(devfreq, 1155 DEVFREQ_GOV_RESUME, NULL); 1156 if (ret) 1157 return ret; 1158 } 1159 1160 return 0; 1161} 1162EXPORT_SYMBOL(devfreq_resume_device); 1163 1164/** 1165 * devfreq_suspend() - Suspend devfreq governors and devices 1166 * 1167 * Called during system wide Suspend/Hibernate cycles for suspending governors 1168 * and devices preserving the state for resume. On some platforms the devfreq 1169 * device must have precise state (frequency) after resume in order to provide 1170 * fully operating setup. 1171 */ 1172void devfreq_suspend(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_suspend_device(devfreq); 1180 if (ret) 1181 dev_err(&devfreq->dev, 1182 "failed to suspend devfreq device\n"); 1183 } 1184 mutex_unlock(&devfreq_list_lock); 1185} 1186 1187/** 1188 * devfreq_resume() - Resume devfreq governors and devices 1189 * 1190 * Called during system wide Suspend/Hibernate cycle for resuming governors and 1191 * devices that are suspended with devfreq_suspend(). 1192 */ 1193void devfreq_resume(void) 1194{ 1195 struct devfreq *devfreq; 1196 int ret; 1197 1198 mutex_lock(&devfreq_list_lock); 1199 list_for_each_entry(devfreq, &devfreq_list, node) { 1200 ret = devfreq_resume_device(devfreq); 1201 if (ret) 1202 dev_warn(&devfreq->dev, 1203 "failed to resume devfreq device\n"); 1204 } 1205 mutex_unlock(&devfreq_list_lock); 1206} 1207 1208/** 1209 * devfreq_add_governor() - Add devfreq governor 1210 * @governor: the devfreq governor to be added 1211 */ 1212int devfreq_add_governor(struct devfreq_governor *governor) 1213{ 1214 struct devfreq_governor *g; 1215 struct devfreq *devfreq; 1216 int err = 0; 1217 1218 if (!governor) { 1219 pr_err("%s: Invalid parameters.\n", __func__); 1220 return -EINVAL; 1221 } 1222 1223 mutex_lock(&devfreq_list_lock); 1224 g = find_devfreq_governor(governor->name); 1225 if (!IS_ERR(g)) { 1226 pr_err("%s: governor %s already registered\n", __func__, 1227 g->name); 1228 err = -EINVAL; 1229 goto err_out; 1230 } 1231 1232 list_add(&governor->node, &devfreq_governor_list); 1233 1234 list_for_each_entry(devfreq, &devfreq_list, node) { 1235 int ret = 0; 1236 struct device *dev = devfreq->dev.parent; 1237 1238 if (!strncmp(devfreq->governor_name, governor->name, 1239 DEVFREQ_NAME_LEN)) { 1240 /* The following should never occur */ 1241 if (devfreq->governor) { 1242 dev_warn(dev, 1243 "%s: Governor %s already present\n", 1244 __func__, devfreq->governor->name); 1245 ret = devfreq->governor->event_handler(devfreq, 1246 DEVFREQ_GOV_STOP, NULL); 1247 if (ret) { 1248 dev_warn(dev, 1249 "%s: Governor %s stop = %d\n", 1250 __func__, 1251 devfreq->governor->name, ret); 1252 } 1253 /* Fall through */ 1254 } 1255 devfreq->governor = governor; 1256 ret = devfreq->governor->event_handler(devfreq, 1257 DEVFREQ_GOV_START, NULL); 1258 if (ret) { 1259 dev_warn(dev, "%s: Governor %s start=%d\n", 1260 __func__, devfreq->governor->name, 1261 ret); 1262 } 1263 } 1264 } 1265 1266err_out: 1267 mutex_unlock(&devfreq_list_lock); 1268 1269 return err; 1270} 1271EXPORT_SYMBOL(devfreq_add_governor); 1272 1273/** 1274 * devfreq_remove_governor() - Remove devfreq feature from a device. 1275 * @governor: the devfreq governor to be removed 1276 */ 1277int devfreq_remove_governor(struct devfreq_governor *governor) 1278{ 1279 struct devfreq_governor *g; 1280 struct devfreq *devfreq; 1281 int err = 0; 1282 1283 if (!governor) { 1284 pr_err("%s: Invalid parameters.\n", __func__); 1285 return -EINVAL; 1286 } 1287 1288 mutex_lock(&devfreq_list_lock); 1289 g = find_devfreq_governor(governor->name); 1290 if (IS_ERR(g)) { 1291 pr_err("%s: governor %s not registered\n", __func__, 1292 governor->name); 1293 err = PTR_ERR(g); 1294 goto err_out; 1295 } 1296 list_for_each_entry(devfreq, &devfreq_list, node) { 1297 int ret; 1298 struct device *dev = devfreq->dev.parent; 1299 1300 if (!strncmp(devfreq->governor_name, governor->name, 1301 DEVFREQ_NAME_LEN)) { 1302 /* we should have a devfreq governor! */ 1303 if (!devfreq->governor) { 1304 dev_warn(dev, "%s: Governor %s NOT present\n", 1305 __func__, governor->name); 1306 continue; 1307 /* Fall through */ 1308 } 1309 ret = devfreq->governor->event_handler(devfreq, 1310 DEVFREQ_GOV_STOP, NULL); 1311 if (ret) { 1312 dev_warn(dev, "%s: Governor %s stop=%d\n", 1313 __func__, devfreq->governor->name, 1314 ret); 1315 } 1316 devfreq->governor = NULL; 1317 } 1318 } 1319 1320 list_del(&governor->node); 1321err_out: 1322 mutex_unlock(&devfreq_list_lock); 1323 1324 return err; 1325} 1326EXPORT_SYMBOL(devfreq_remove_governor); 1327 1328static ssize_t name_show(struct device *dev, 1329 struct device_attribute *attr, char *buf) 1330{ 1331 struct devfreq *df = to_devfreq(dev); 1332 return sprintf(buf, "%s\n", dev_name(df->dev.parent)); 1333} 1334static DEVICE_ATTR_RO(name); 1335 1336static ssize_t governor_show(struct device *dev, 1337 struct device_attribute *attr, char *buf) 1338{ 1339 struct devfreq *df = to_devfreq(dev); 1340 1341 if (!df->governor) 1342 return -EINVAL; 1343 1344 return sprintf(buf, "%s\n", df->governor->name); 1345} 1346 1347static ssize_t governor_store(struct device *dev, struct device_attribute *attr, 1348 const char *buf, size_t count) 1349{ 1350 struct devfreq *df = to_devfreq(dev); 1351 int ret; 1352 char str_governor[DEVFREQ_NAME_LEN + 1]; 1353 const struct devfreq_governor *governor, *prev_governor; 1354 1355 if (!df->governor) 1356 return -EINVAL; 1357 1358 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); 1359 if (ret != 1) 1360 return -EINVAL; 1361 1362 mutex_lock(&devfreq_list_lock); 1363 governor = try_then_request_governor(str_governor); 1364 if (IS_ERR(governor)) { 1365 ret = PTR_ERR(governor); 1366 goto out; 1367 } 1368 if (df->governor == governor) { 1369 ret = 0; 1370 goto out; 1371 } else if (df->governor->immutable || governor->immutable) { 1372 ret = -EINVAL; 1373 goto out; 1374 } 1375 1376 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); 1377 if (ret) { 1378 dev_warn(dev, "%s: Governor %s not stopped(%d)\n", 1379 __func__, df->governor->name, ret); 1380 goto out; 1381 } 1382 1383 prev_governor = df->governor; 1384 df->governor = governor; 1385 strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); 1386 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1387 if (ret) { 1388 dev_warn(dev, "%s: Governor %s not started(%d)\n", 1389 __func__, df->governor->name, ret); 1390 df->governor = prev_governor; 1391 strncpy(df->governor_name, prev_governor->name, 1392 DEVFREQ_NAME_LEN); 1393 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1394 if (ret) { 1395 dev_err(dev, 1396 "%s: reverting to Governor %s failed (%d)\n", 1397 __func__, df->governor_name, ret); 1398 df->governor = NULL; 1399 } 1400 } 1401out: 1402 mutex_unlock(&devfreq_list_lock); 1403 1404 if (!ret) 1405 ret = count; 1406 return ret; 1407} 1408static DEVICE_ATTR_RW(governor); 1409 1410static ssize_t available_governors_show(struct device *d, 1411 struct device_attribute *attr, 1412 char *buf) 1413{ 1414 struct devfreq *df = to_devfreq(d); 1415 ssize_t count = 0; 1416 1417 if (!df->governor) 1418 return -EINVAL; 1419 1420 mutex_lock(&devfreq_list_lock); 1421 1422 /* 1423 * The devfreq with immutable governor (e.g., passive) shows 1424 * only own governor. 1425 */ 1426 if (df->governor->immutable) { 1427 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN, 1428 "%s ", df->governor_name); 1429 /* 1430 * The devfreq device shows the registered governor except for 1431 * immutable governors such as passive governor . 1432 */ 1433 } else { 1434 struct devfreq_governor *governor; 1435 1436 list_for_each_entry(governor, &devfreq_governor_list, node) { 1437 if (governor->immutable) 1438 continue; 1439 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), 1440 "%s ", governor->name); 1441 } 1442 } 1443 1444 mutex_unlock(&devfreq_list_lock); 1445 1446 /* Truncate the trailing space */ 1447 if (count) 1448 count--; 1449 1450 count += sprintf(&buf[count], "\n"); 1451 1452 return count; 1453} 1454static DEVICE_ATTR_RO(available_governors); 1455 1456static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, 1457 char *buf) 1458{ 1459 unsigned long freq; 1460 struct devfreq *df = to_devfreq(dev); 1461 1462 if (!df->profile) 1463 return -EINVAL; 1464 1465 if (df->profile->get_cur_freq && 1466 !df->profile->get_cur_freq(df->dev.parent, &freq)) 1467 return sprintf(buf, "%lu\n", freq); 1468 1469 return sprintf(buf, "%lu\n", df->previous_freq); 1470} 1471static DEVICE_ATTR_RO(cur_freq); 1472 1473static ssize_t target_freq_show(struct device *dev, 1474 struct device_attribute *attr, char *buf) 1475{ 1476 struct devfreq *df = to_devfreq(dev); 1477 1478 return sprintf(buf, "%lu\n", df->previous_freq); 1479} 1480static DEVICE_ATTR_RO(target_freq); 1481 1482static ssize_t polling_interval_show(struct device *dev, 1483 struct device_attribute *attr, char *buf) 1484{ 1485 struct devfreq *df = to_devfreq(dev); 1486 1487 if (!df->profile) 1488 return -EINVAL; 1489 1490 return sprintf(buf, "%d\n", df->profile->polling_ms); 1491} 1492 1493static ssize_t polling_interval_store(struct device *dev, 1494 struct device_attribute *attr, 1495 const char *buf, size_t count) 1496{ 1497 struct devfreq *df = to_devfreq(dev); 1498 unsigned int value; 1499 int ret; 1500 1501 if (!df->governor) 1502 return -EINVAL; 1503 1504 ret = sscanf(buf, "%u", &value); 1505 if (ret != 1) 1506 return -EINVAL; 1507 1508 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value); 1509 ret = count; 1510 1511 return ret; 1512} 1513static DEVICE_ATTR_RW(polling_interval); 1514 1515static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, 1516 const char *buf, size_t count) 1517{ 1518 struct devfreq *df = to_devfreq(dev); 1519 unsigned long value; 1520 int ret; 1521 1522 /* 1523 * Protect against theoretical sysfs writes between 1524 * device_add and dev_pm_qos_add_request 1525 */ 1526 if (!dev_pm_qos_request_active(&df->user_min_freq_req)) 1527 return -EAGAIN; 1528 1529 ret = sscanf(buf, "%lu", &value); 1530 if (ret != 1) 1531 return -EINVAL; 1532 1533 /* Round down to kHz for PM QoS */ 1534 ret = dev_pm_qos_update_request(&df->user_min_freq_req, 1535 value / HZ_PER_KHZ); 1536 if (ret < 0) 1537 return ret; 1538 1539 return count; 1540} 1541 1542static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, 1543 char *buf) 1544{ 1545 struct devfreq *df = to_devfreq(dev); 1546 unsigned long min_freq, max_freq; 1547 1548 mutex_lock(&df->lock); 1549 get_freq_range(df, &min_freq, &max_freq); 1550 mutex_unlock(&df->lock); 1551 1552 return sprintf(buf, "%lu\n", min_freq); 1553} 1554static DEVICE_ATTR_RW(min_freq); 1555 1556static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, 1557 const char *buf, size_t count) 1558{ 1559 struct devfreq *df = to_devfreq(dev); 1560 unsigned long value; 1561 int ret; 1562 1563 /* 1564 * Protect against theoretical sysfs writes between 1565 * device_add and dev_pm_qos_add_request 1566 */ 1567 if (!dev_pm_qos_request_active(&df->user_max_freq_req)) 1568 return -EINVAL; 1569 1570 ret = sscanf(buf, "%lu", &value); 1571 if (ret != 1) 1572 return -EINVAL; 1573 1574 /* 1575 * PM QoS frequencies are in kHz so we need to convert. Convert by 1576 * rounding upwards so that the acceptable interval never shrinks. 1577 * 1578 * For example if the user writes "666666666" to sysfs this value will 1579 * be converted to 666667 kHz and back to 666667000 Hz before an OPP 1580 * lookup, this ensures that an OPP of 666666666Hz is still accepted. 1581 * 1582 * A value of zero means "no limit". 1583 */ 1584 if (value) 1585 value = DIV_ROUND_UP(value, HZ_PER_KHZ); 1586 else 1587 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; 1588 1589 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); 1590 if (ret < 0) 1591 return ret; 1592 1593 return count; 1594} 1595 1596static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, 1597 char *buf) 1598{ 1599 struct devfreq *df = to_devfreq(dev); 1600 unsigned long min_freq, max_freq; 1601 1602 mutex_lock(&df->lock); 1603 get_freq_range(df, &min_freq, &max_freq); 1604 mutex_unlock(&df->lock); 1605 1606 return sprintf(buf, "%lu\n", max_freq); 1607} 1608static DEVICE_ATTR_RW(max_freq); 1609 1610static ssize_t available_frequencies_show(struct device *d, 1611 struct device_attribute *attr, 1612 char *buf) 1613{ 1614 struct devfreq *df = to_devfreq(d); 1615 ssize_t count = 0; 1616 int i; 1617 1618 if (!df->profile) 1619 return -EINVAL; 1620 1621 mutex_lock(&df->lock); 1622 1623 for (i = 0; i < df->profile->max_state; i++) 1624 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), 1625 "%lu ", df->profile->freq_table[i]); 1626 1627 mutex_unlock(&df->lock); 1628 /* Truncate the trailing space */ 1629 if (count) 1630 count--; 1631 1632 count += sprintf(&buf[count], "\n"); 1633 1634 return count; 1635} 1636static DEVICE_ATTR_RO(available_frequencies); 1637 1638static ssize_t trans_stat_show(struct device *dev, 1639 struct device_attribute *attr, char *buf) 1640{ 1641 struct devfreq *df = to_devfreq(dev); 1642 ssize_t len = 0; 1643 int i, j; 1644 unsigned int max_state; 1645 1646 if (!df->profile) 1647 return -EINVAL; 1648 max_state = df->profile->max_state; 1649 1650 if (max_state == 0) 1651 return scnprintf(buf, PAGE_SIZE, "Not Supported.\n"); 1652 1653 mutex_lock(&df->lock); 1654 if (!df->stop_polling && 1655 devfreq_update_status(df, df->previous_freq)) { 1656 mutex_unlock(&df->lock); 1657 return 0; 1658 } 1659 mutex_unlock(&df->lock); 1660 1661 len += scnprintf(buf + len, PAGE_SIZE - len, " From : To\n"); 1662 len += scnprintf(buf + len, PAGE_SIZE - len, " :"); 1663 for (i = 0; i < max_state; i++) { 1664 if (len >= PAGE_SIZE - 1) 1665 break; 1666 len += scnprintf(buf + len, PAGE_SIZE - len, "%10lu", 1667 df->profile->freq_table[i]); 1668 } 1669 if (len >= PAGE_SIZE - 1) 1670 return PAGE_SIZE - 1; 1671 1672 len += scnprintf(buf + len, PAGE_SIZE - len, " time(ms)\n"); 1673 1674 for (i = 0; i < max_state; i++) { 1675 if (len >= PAGE_SIZE - 1) 1676 break; 1677 if (df->profile->freq_table[i] 1678 == df->previous_freq) { 1679 len += scnprintf(buf + len, PAGE_SIZE - len, "*"); 1680 } else { 1681 len += scnprintf(buf + len, PAGE_SIZE - len, " "); 1682 } 1683 if (len >= PAGE_SIZE - 1) 1684 break; 1685 1686 len += scnprintf(buf + len, PAGE_SIZE - len, "%10lu:", 1687 df->profile->freq_table[i]); 1688 for (j = 0; j < max_state; j++) { 1689 if (len >= PAGE_SIZE - 1) 1690 break; 1691 len += scnprintf(buf + len, PAGE_SIZE - len, "%10u", 1692 df->stats.trans_table[(i * max_state) + j]); 1693 } 1694 if (len >= PAGE_SIZE - 1) 1695 break; 1696 len += scnprintf(buf + len, PAGE_SIZE - len, "%10llu\n", (u64) 1697 jiffies64_to_msecs(df->stats.time_in_state[i])); 1698 } 1699 1700 if (len < PAGE_SIZE - 1) 1701 len += scnprintf(buf + len, PAGE_SIZE - len, "Total transition : %u\n", 1702 df->stats.total_trans); 1703 1704 if (len >= PAGE_SIZE - 1) { 1705 pr_warn_once("devfreq transition table exceeds PAGE_SIZE. Disabling\n"); 1706 return -EFBIG; 1707 } 1708 1709 return len; 1710} 1711 1712static ssize_t trans_stat_store(struct device *dev, 1713 struct device_attribute *attr, 1714 const char *buf, size_t count) 1715{ 1716 struct devfreq *df = to_devfreq(dev); 1717 int err, value; 1718 1719 if (!df->profile) 1720 return -EINVAL; 1721 1722 if (df->profile->max_state == 0) 1723 return count; 1724 1725 err = kstrtoint(buf, 10, &value); 1726 if (err || value != 0) 1727 return -EINVAL; 1728 1729 mutex_lock(&df->lock); 1730 memset(df->stats.time_in_state, 0, (df->profile->max_state * 1731 sizeof(*df->stats.time_in_state))); 1732 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int), 1733 df->profile->max_state, 1734 df->profile->max_state)); 1735 df->stats.total_trans = 0; 1736 df->stats.last_update = get_jiffies_64(); 1737 mutex_unlock(&df->lock); 1738 1739 return count; 1740} 1741static DEVICE_ATTR_RW(trans_stat); 1742 1743static ssize_t timer_show(struct device *dev, 1744 struct device_attribute *attr, char *buf) 1745{ 1746 struct devfreq *df = to_devfreq(dev); 1747 1748 if (!df->profile) 1749 return -EINVAL; 1750 1751 return sprintf(buf, "%s\n", timer_name[df->profile->timer]); 1752} 1753 1754static ssize_t timer_store(struct device *dev, struct device_attribute *attr, 1755 const char *buf, size_t count) 1756{ 1757 struct devfreq *df = to_devfreq(dev); 1758 char str_timer[DEVFREQ_NAME_LEN + 1]; 1759 int timer = -1; 1760 int ret = 0, i; 1761 1762 if (!df->governor || !df->profile) 1763 return -EINVAL; 1764 1765 ret = sscanf(buf, "%16s", str_timer); 1766 if (ret != 1) 1767 return -EINVAL; 1768 1769 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) { 1770 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) { 1771 timer = i; 1772 break; 1773 } 1774 } 1775 1776 if (timer < 0) { 1777 ret = -EINVAL; 1778 goto out; 1779 } 1780 1781 if (df->profile->timer == timer) { 1782 ret = 0; 1783 goto out; 1784 } 1785 1786 mutex_lock(&df->lock); 1787 df->profile->timer = timer; 1788 mutex_unlock(&df->lock); 1789 1790 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); 1791 if (ret) { 1792 dev_warn(dev, "%s: Governor %s not stopped(%d)\n", 1793 __func__, df->governor->name, ret); 1794 goto out; 1795 } 1796 1797 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1798 if (ret) 1799 dev_warn(dev, "%s: Governor %s not started(%d)\n", 1800 __func__, df->governor->name, ret); 1801out: 1802 return ret ? ret : count; 1803} 1804static DEVICE_ATTR_RW(timer); 1805 1806static struct attribute *devfreq_attrs[] = { 1807 &dev_attr_name.attr, 1808 &dev_attr_governor.attr, 1809 &dev_attr_available_governors.attr, 1810 &dev_attr_cur_freq.attr, 1811 &dev_attr_available_frequencies.attr, 1812 &dev_attr_target_freq.attr, 1813 &dev_attr_polling_interval.attr, 1814 &dev_attr_min_freq.attr, 1815 &dev_attr_max_freq.attr, 1816 &dev_attr_trans_stat.attr, 1817 &dev_attr_timer.attr, 1818 NULL, 1819}; 1820ATTRIBUTE_GROUPS(devfreq); 1821 1822/** 1823 * devfreq_summary_show() - Show the summary of the devfreq devices 1824 * @s: seq_file instance to show the summary of devfreq devices 1825 * @data: not used 1826 * 1827 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. 1828 * It helps that user can know the detailed information of the devfreq devices. 1829 * 1830 * Return 0 always because it shows the information without any data change. 1831 */ 1832static int devfreq_summary_show(struct seq_file *s, void *data) 1833{ 1834 struct devfreq *devfreq; 1835 struct devfreq *p_devfreq = NULL; 1836 unsigned long cur_freq, min_freq, max_freq; 1837 unsigned int polling_ms; 1838 unsigned int timer; 1839 1840 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n", 1841 "dev", 1842 "parent_dev", 1843 "governor", 1844 "timer", 1845 "polling_ms", 1846 "cur_freq_Hz", 1847 "min_freq_Hz", 1848 "max_freq_Hz"); 1849 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n", 1850 "------------------------------", 1851 "------------------------------", 1852 "---------------", 1853 "----------", 1854 "----------", 1855 "------------", 1856 "------------", 1857 "------------"); 1858 1859 mutex_lock(&devfreq_list_lock); 1860 1861 list_for_each_entry_reverse(devfreq, &devfreq_list, node) { 1862#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) 1863 if (!strncmp(devfreq->governor_name, DEVFREQ_GOV_PASSIVE, 1864 DEVFREQ_NAME_LEN)) { 1865 struct devfreq_passive_data *data = devfreq->data; 1866 1867 if (data) 1868 p_devfreq = data->parent; 1869 } else { 1870 p_devfreq = NULL; 1871 } 1872#endif 1873 1874 mutex_lock(&devfreq->lock); 1875 cur_freq = devfreq->previous_freq; 1876 get_freq_range(devfreq, &min_freq, &max_freq); 1877 polling_ms = devfreq->profile->polling_ms; 1878 timer = devfreq->profile->timer; 1879 mutex_unlock(&devfreq->lock); 1880 1881 seq_printf(s, 1882 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n", 1883 dev_name(&devfreq->dev), 1884 p_devfreq ? dev_name(&p_devfreq->dev) : "null", 1885 devfreq->governor_name, 1886 polling_ms ? timer_name[timer] : "null", 1887 polling_ms, 1888 cur_freq, 1889 min_freq, 1890 max_freq); 1891 } 1892 1893 mutex_unlock(&devfreq_list_lock); 1894 1895 return 0; 1896} 1897DEFINE_SHOW_ATTRIBUTE(devfreq_summary); 1898 1899static int __init devfreq_init(void) 1900{ 1901 devfreq_class = class_create(THIS_MODULE, "devfreq"); 1902 if (IS_ERR(devfreq_class)) { 1903 pr_err("%s: couldn't create class\n", __FILE__); 1904 return PTR_ERR(devfreq_class); 1905 } 1906 1907 devfreq_wq = create_freezable_workqueue("devfreq_wq"); 1908 if (!devfreq_wq) { 1909 class_destroy(devfreq_class); 1910 pr_err("%s: couldn't create workqueue\n", __FILE__); 1911 return -ENOMEM; 1912 } 1913 devfreq_class->dev_groups = devfreq_groups; 1914 1915 devfreq_debugfs = debugfs_create_dir("devfreq", NULL); 1916 debugfs_create_file("devfreq_summary", 0444, 1917 devfreq_debugfs, NULL, 1918 &devfreq_summary_fops); 1919 1920 return 0; 1921} 1922subsys_initcall(devfreq_init); 1923 1924/* 1925 * The following are helper functions for devfreq user device drivers with 1926 * OPP framework. 1927 */ 1928 1929/** 1930 * devfreq_recommended_opp() - Helper function to get proper OPP for the 1931 * freq value given to target callback. 1932 * @dev: The devfreq user device. (parent of devfreq) 1933 * @freq: The frequency given to target function 1934 * @flags: Flags handed from devfreq framework. 1935 * 1936 * The callers are required to call dev_pm_opp_put() for the returned OPP after 1937 * use. 1938 */ 1939struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, 1940 unsigned long *freq, 1941 u32 flags) 1942{ 1943 struct dev_pm_opp *opp; 1944 1945 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { 1946 /* The freq is an upper bound. opp should be lower */ 1947 opp = dev_pm_opp_find_freq_floor(dev, freq); 1948 1949 /* If not available, use the closest opp */ 1950 if (opp == ERR_PTR(-ERANGE)) 1951 opp = dev_pm_opp_find_freq_ceil(dev, freq); 1952 } else { 1953 /* The freq is an lower bound. opp should be higher */ 1954 opp = dev_pm_opp_find_freq_ceil(dev, freq); 1955 1956 /* If not available, use the closest opp */ 1957 if (opp == ERR_PTR(-ERANGE)) 1958 opp = dev_pm_opp_find_freq_floor(dev, freq); 1959 } 1960 1961 return opp; 1962} 1963EXPORT_SYMBOL(devfreq_recommended_opp); 1964 1965/** 1966 * devfreq_register_opp_notifier() - Helper function to get devfreq notified 1967 * for any changes in the OPP availability 1968 * changes 1969 * @dev: The devfreq user device. (parent of devfreq) 1970 * @devfreq: The devfreq object. 1971 */ 1972int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) 1973{ 1974 return dev_pm_opp_register_notifier(dev, &devfreq->nb); 1975} 1976EXPORT_SYMBOL(devfreq_register_opp_notifier); 1977 1978/** 1979 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq 1980 * notified for any changes in the OPP 1981 * availability changes anymore. 1982 * @dev: The devfreq user device. (parent of devfreq) 1983 * @devfreq: The devfreq object. 1984 * 1985 * At exit() callback of devfreq_dev_profile, this must be included if 1986 * devfreq_recommended_opp is used. 1987 */ 1988int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) 1989{ 1990 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb); 1991} 1992EXPORT_SYMBOL(devfreq_unregister_opp_notifier); 1993 1994static void devm_devfreq_opp_release(struct device *dev, void *res) 1995{ 1996 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res); 1997} 1998 1999/** 2000 * devm_devfreq_register_opp_notifier() - Resource-managed 2001 * devfreq_register_opp_notifier() 2002 * @dev: The devfreq user device. (parent of devfreq) 2003 * @devfreq: The devfreq object. 2004 */ 2005int devm_devfreq_register_opp_notifier(struct device *dev, 2006 struct devfreq *devfreq) 2007{ 2008 struct devfreq **ptr; 2009 int ret; 2010 2011 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL); 2012 if (!ptr) 2013 return -ENOMEM; 2014 2015 ret = devfreq_register_opp_notifier(dev, devfreq); 2016 if (ret) { 2017 devres_free(ptr); 2018 return ret; 2019 } 2020 2021 *ptr = devfreq; 2022 devres_add(dev, ptr); 2023 2024 return 0; 2025} 2026EXPORT_SYMBOL(devm_devfreq_register_opp_notifier); 2027 2028/** 2029 * devm_devfreq_unregister_opp_notifier() - Resource-managed 2030 * devfreq_unregister_opp_notifier() 2031 * @dev: The devfreq user device. (parent of devfreq) 2032 * @devfreq: The devfreq object. 2033 */ 2034void devm_devfreq_unregister_opp_notifier(struct device *dev, 2035 struct devfreq *devfreq) 2036{ 2037 WARN_ON(devres_release(dev, devm_devfreq_opp_release, 2038 devm_devfreq_dev_match, devfreq)); 2039} 2040EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier); 2041 2042/** 2043 * devfreq_register_notifier() - Register a driver with devfreq 2044 * @devfreq: The devfreq object. 2045 * @nb: The notifier block to register. 2046 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2047 */ 2048int devfreq_register_notifier(struct devfreq *devfreq, 2049 struct notifier_block *nb, 2050 unsigned int list) 2051{ 2052 int ret = 0; 2053 2054 if (!devfreq) 2055 return -EINVAL; 2056 2057 switch (list) { 2058 case DEVFREQ_TRANSITION_NOTIFIER: 2059 ret = srcu_notifier_chain_register( 2060 &devfreq->transition_notifier_list, nb); 2061 break; 2062 default: 2063 ret = -EINVAL; 2064 } 2065 2066 return ret; 2067} 2068EXPORT_SYMBOL(devfreq_register_notifier); 2069 2070/* 2071 * devfreq_unregister_notifier() - Unregister a driver with devfreq 2072 * @devfreq: The devfreq object. 2073 * @nb: The notifier block to be unregistered. 2074 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2075 */ 2076int devfreq_unregister_notifier(struct devfreq *devfreq, 2077 struct notifier_block *nb, 2078 unsigned int list) 2079{ 2080 int ret = 0; 2081 2082 if (!devfreq) 2083 return -EINVAL; 2084 2085 switch (list) { 2086 case DEVFREQ_TRANSITION_NOTIFIER: 2087 ret = srcu_notifier_chain_unregister( 2088 &devfreq->transition_notifier_list, nb); 2089 break; 2090 default: 2091 ret = -EINVAL; 2092 } 2093 2094 return ret; 2095} 2096EXPORT_SYMBOL(devfreq_unregister_notifier); 2097 2098struct devfreq_notifier_devres { 2099 struct devfreq *devfreq; 2100 struct notifier_block *nb; 2101 unsigned int list; 2102}; 2103 2104static void devm_devfreq_notifier_release(struct device *dev, void *res) 2105{ 2106 struct devfreq_notifier_devres *this = res; 2107 2108 devfreq_unregister_notifier(this->devfreq, this->nb, this->list); 2109} 2110 2111/** 2112 * devm_devfreq_register_notifier() 2113 * - Resource-managed devfreq_register_notifier() 2114 * @dev: The devfreq user device. (parent of devfreq) 2115 * @devfreq: The devfreq object. 2116 * @nb: The notifier block to be unregistered. 2117 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2118 */ 2119int devm_devfreq_register_notifier(struct device *dev, 2120 struct devfreq *devfreq, 2121 struct notifier_block *nb, 2122 unsigned int list) 2123{ 2124 struct devfreq_notifier_devres *ptr; 2125 int ret; 2126 2127 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr), 2128 GFP_KERNEL); 2129 if (!ptr) 2130 return -ENOMEM; 2131 2132 ret = devfreq_register_notifier(devfreq, nb, list); 2133 if (ret) { 2134 devres_free(ptr); 2135 return ret; 2136 } 2137 2138 ptr->devfreq = devfreq; 2139 ptr->nb = nb; 2140 ptr->list = list; 2141 devres_add(dev, ptr); 2142 2143 return 0; 2144} 2145EXPORT_SYMBOL(devm_devfreq_register_notifier); 2146 2147/** 2148 * devm_devfreq_unregister_notifier() 2149 * - Resource-managed devfreq_unregister_notifier() 2150 * @dev: The devfreq user device. (parent of devfreq) 2151 * @devfreq: The devfreq object. 2152 * @nb: The notifier block to be unregistered. 2153 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2154 */ 2155void devm_devfreq_unregister_notifier(struct device *dev, 2156 struct devfreq *devfreq, 2157 struct notifier_block *nb, 2158 unsigned int list) 2159{ 2160 WARN_ON(devres_release(dev, devm_devfreq_notifier_release, 2161 devm_devfreq_dev_match, devfreq)); 2162} 2163EXPORT_SYMBOL(devm_devfreq_unregister_notifier); 2164