1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * devfreq: Generic Dynamic Voltage and Frequency Scaling (DVFS) Framework 4 * for Non-CPU Devices. 5 * 6 * Copyright (C) 2011 Samsung Electronics 7 * MyungJoo Ham <myungjoo.ham@samsung.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/kmod.h> 12 #include <linux/sched.h> 13 #include <linux/debugfs.h> 14 #include <linux/devfreq_cooling.h> 15 #include <linux/errno.h> 16 #include <linux/err.h> 17 #include <linux/init.h> 18 #include <linux/export.h> 19 #include <linux/slab.h> 20 #include <linux/stat.h> 21 #include <linux/pm_opp.h> 22 #include <linux/devfreq.h> 23 #include <linux/workqueue.h> 24 #include <linux/platform_device.h> 25 #include <linux/list.h> 26 #include <linux/printk.h> 27 #include <linux/hrtimer.h> 28 #include <linux/of.h> 29 #include <linux/pm_qos.h> 30 #include <linux/units.h> 31 #include "governor.h" 32 33 #define CREATE_TRACE_POINTS 34 #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 39 static struct class *devfreq_class; 40 static struct dentry *devfreq_debugfs; 41 42 /* 43 * devfreq core provides delayed work based load monitoring helper 44 * functions. Governors can use these or can implement their own 45 * monitoring mechanism. 46 */ 47 static struct workqueue_struct *devfreq_wq; 48 49 /* The list of all device-devfreq governors */ 50 static LIST_HEAD(devfreq_governor_list); 51 /* The list of all device-devfreq */ 52 static LIST_HEAD(devfreq_list); 53 static DEFINE_MUTEX(devfreq_list_lock); 54 55 static const char timer_name[][DEVFREQ_NAME_LEN] = { 56 [DEVFREQ_TIMER_DEFERRABLE] = { "deferrable" }, 57 [DEVFREQ_TIMER_DELAYED] = { "delayed" }, 58 }; 59 60 /** 61 * find_device_devfreq() - find devfreq struct using device pointer 62 * @dev: device pointer used to lookup device devfreq. 63 * 64 * Search the list of device devfreqs and return the matched device's 65 * devfreq info. devfreq_list_lock should be held by the caller. 66 */ 67 static 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 86 static 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 else 95 dev_pm_opp_put(opp); 96 97 return min_freq; 98 } 99 100 static 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 else 109 dev_pm_opp_put(opp); 110 111 return max_freq; 112 } 113 114 /** 115 * devfreq_get_freq_range() - Get the current freq range 116 * @devfreq: the devfreq instance 117 * @min_freq: the min frequency 118 * @max_freq: the max frequency 119 * 120 * This takes into consideration all constraints. 121 */ 122 void 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 or 134 * 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 } 161 EXPORT_SYMBOL(devfreq_get_freq_range); 162 163 /** 164 * devfreq_get_freq_level() - Lookup freq_table for the frequency 165 * @devfreq: the devfreq instance 166 * @freq: the target frequency 167 */ 168 static 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 } 178 179 static 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 behavior 213 * @devfreq: the devfreq instance 214 * @freq: the update target frequency 215 */ 216 int 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 } 248 249 out: 250 devfreq->stats.last_update = cur_time; 251 return ret; 252 } 253 EXPORT_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 */ 262 static 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 */ 292 static 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 } 323 324 static 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 } 346 347 static 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 /* 371 * Print devfreq_frequency trace information between DEVFREQ_PRECHANGE 372 * and DEVFREQ_POSTCHANGE because for showing the correct frequency 373 * 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 frequency 395 * on the final stage. 396 * @devfreq: the devfreq instance. 397 * @freq: the new frequency of parent device. This argument 398 * is only used for devfreq device using passive governor. 399 * 400 * Note: Lock devfreq->lock before calling devfreq_update_target. This function 401 * should be only used by both update_devfreq() and devfreq governors. 402 */ 403 int 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 } 431 EXPORT_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_devfreq 440 * This function is exported for governors. 441 */ 442 int update_devfreq(struct devfreq *devfreq) 443 { 444 return devfreq_update_target(devfreq, 0L); 445 } 446 EXPORT_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 */ 453 static 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 queue_delayed_work(devfreq_wq, &devfreq->work, 465 msecs_to_jiffies(devfreq->profile->polling_ms)); 466 mutex_unlock(&devfreq->lock); 467 468 trace_devfreq_monitor(devfreq); 469 } 470 471 /** 472 * devfreq_monitor_start() - Start load monitoring of devfreq instance 473 * @devfreq: the devfreq instance. 474 * 475 * Helper function for starting devfreq device load monitoring. By default, 476 * deferrable timer is used for load monitoring. But the users can change this 477 * behavior using the "timer" type in devfreq_dev_profile. This function will be 478 * called by devfreq governor in response to the DEVFREQ_GOV_START event 479 * generated while adding a device to the devfreq framework. 480 */ 481 void devfreq_monitor_start(struct devfreq *devfreq) 482 { 483 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 484 return; 485 486 switch (devfreq->profile->timer) { 487 case DEVFREQ_TIMER_DEFERRABLE: 488 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); 489 break; 490 case DEVFREQ_TIMER_DELAYED: 491 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor); 492 break; 493 default: 494 return; 495 } 496 497 if (devfreq->profile->polling_ms) 498 queue_delayed_work(devfreq_wq, &devfreq->work, 499 msecs_to_jiffies(devfreq->profile->polling_ms)); 500 } 501 EXPORT_SYMBOL(devfreq_monitor_start); 502 503 /** 504 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance 505 * @devfreq: the devfreq instance. 506 * 507 * Helper function to stop devfreq device load monitoring. Function 508 * to be called from governor in response to DEVFREQ_GOV_STOP 509 * event when device is removed from devfreq framework. 510 */ 511 void devfreq_monitor_stop(struct devfreq *devfreq) 512 { 513 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 514 return; 515 516 cancel_delayed_work_sync(&devfreq->work); 517 } 518 EXPORT_SYMBOL(devfreq_monitor_stop); 519 520 /** 521 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance 522 * @devfreq: the devfreq instance. 523 * 524 * Helper function to suspend devfreq device load monitoring. Function 525 * to be called from governor in response to DEVFREQ_GOV_SUSPEND 526 * event or when polling interval is set to zero. 527 * 528 * Note: Though this function is same as devfreq_monitor_stop(), 529 * intentionally kept separate to provide hooks for collecting 530 * transition statistics. 531 */ 532 void devfreq_monitor_suspend(struct devfreq *devfreq) 533 { 534 mutex_lock(&devfreq->lock); 535 if (devfreq->stop_polling) { 536 mutex_unlock(&devfreq->lock); 537 return; 538 } 539 540 devfreq_update_status(devfreq, devfreq->previous_freq); 541 devfreq->stop_polling = true; 542 mutex_unlock(&devfreq->lock); 543 544 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 545 return; 546 547 cancel_delayed_work_sync(&devfreq->work); 548 } 549 EXPORT_SYMBOL(devfreq_monitor_suspend); 550 551 /** 552 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance 553 * @devfreq: the devfreq instance. 554 * 555 * Helper function to resume devfreq device load monitoring. Function 556 * to be called from governor in response to DEVFREQ_GOV_RESUME 557 * event or when polling interval is set to non-zero. 558 */ 559 void devfreq_monitor_resume(struct devfreq *devfreq) 560 { 561 unsigned long freq; 562 563 mutex_lock(&devfreq->lock); 564 565 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 566 goto out_update; 567 568 if (!devfreq->stop_polling) 569 goto out; 570 571 if (!delayed_work_pending(&devfreq->work) && 572 devfreq->profile->polling_ms) 573 queue_delayed_work(devfreq_wq, &devfreq->work, 574 msecs_to_jiffies(devfreq->profile->polling_ms)); 575 576 out_update: 577 devfreq->stats.last_update = get_jiffies_64(); 578 devfreq->stop_polling = false; 579 580 if (devfreq->profile->get_cur_freq && 581 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) 582 devfreq->previous_freq = freq; 583 584 out: 585 mutex_unlock(&devfreq->lock); 586 } 587 EXPORT_SYMBOL(devfreq_monitor_resume); 588 589 /** 590 * devfreq_update_interval() - Update device devfreq monitoring interval 591 * @devfreq: the devfreq instance. 592 * @delay: new polling interval to be set. 593 * 594 * Helper function to set new load monitoring polling interval. Function 595 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event. 596 */ 597 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay) 598 { 599 unsigned int cur_delay = devfreq->profile->polling_ms; 600 unsigned int new_delay = *delay; 601 602 mutex_lock(&devfreq->lock); 603 devfreq->profile->polling_ms = new_delay; 604 605 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 606 goto out; 607 608 if (devfreq->stop_polling) 609 goto out; 610 611 /* if new delay is zero, stop polling */ 612 if (!new_delay) { 613 mutex_unlock(&devfreq->lock); 614 cancel_delayed_work_sync(&devfreq->work); 615 return; 616 } 617 618 /* if current delay is zero, start polling with new delay */ 619 if (!cur_delay) { 620 queue_delayed_work(devfreq_wq, &devfreq->work, 621 msecs_to_jiffies(devfreq->profile->polling_ms)); 622 goto out; 623 } 624 625 /* if current delay is greater than new delay, restart polling */ 626 if (cur_delay > new_delay) { 627 mutex_unlock(&devfreq->lock); 628 cancel_delayed_work_sync(&devfreq->work); 629 mutex_lock(&devfreq->lock); 630 if (!devfreq->stop_polling) 631 queue_delayed_work(devfreq_wq, &devfreq->work, 632 msecs_to_jiffies(devfreq->profile->polling_ms)); 633 } 634 out: 635 mutex_unlock(&devfreq->lock); 636 } 637 EXPORT_SYMBOL(devfreq_update_interval); 638 639 /** 640 * devfreq_notifier_call() - Notify that the device frequency requirements 641 * has been changed out of devfreq framework. 642 * @nb: the notifier_block (supposed to be devfreq->nb) 643 * @type: not used 644 * @devp: not used 645 * 646 * Called by a notifier that uses devfreq->nb. 647 */ 648 static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, 649 void *devp) 650 { 651 struct devfreq *devfreq = container_of(nb, struct devfreq, nb); 652 int err = -EINVAL; 653 654 mutex_lock(&devfreq->lock); 655 656 devfreq->scaling_min_freq = find_available_min_freq(devfreq); 657 if (!devfreq->scaling_min_freq) 658 goto out; 659 660 devfreq->scaling_max_freq = find_available_max_freq(devfreq); 661 if (!devfreq->scaling_max_freq) { 662 devfreq->scaling_max_freq = ULONG_MAX; 663 goto out; 664 } 665 666 err = update_devfreq(devfreq); 667 668 out: 669 mutex_unlock(&devfreq->lock); 670 if (err) 671 dev_err(devfreq->dev.parent, 672 "failed to update frequency from OPP notifier (%d)\n", 673 err); 674 675 return NOTIFY_OK; 676 } 677 678 /** 679 * qos_notifier_call() - Common handler for QoS constraints. 680 * @devfreq: the devfreq instance. 681 */ 682 static int qos_notifier_call(struct devfreq *devfreq) 683 { 684 int err; 685 686 mutex_lock(&devfreq->lock); 687 err = update_devfreq(devfreq); 688 mutex_unlock(&devfreq->lock); 689 if (err) 690 dev_err(devfreq->dev.parent, 691 "failed to update frequency from PM QoS (%d)\n", 692 err); 693 694 return NOTIFY_OK; 695 } 696 697 /** 698 * qos_min_notifier_call() - Callback for QoS min_freq changes. 699 * @nb: Should be devfreq->nb_min 700 * @val: not used 701 * @ptr: not used 702 */ 703 static int qos_min_notifier_call(struct notifier_block *nb, 704 unsigned long val, void *ptr) 705 { 706 return qos_notifier_call(container_of(nb, struct devfreq, nb_min)); 707 } 708 709 /** 710 * qos_max_notifier_call() - Callback for QoS max_freq changes. 711 * @nb: Should be devfreq->nb_max 712 * @val: not used 713 * @ptr: not used 714 */ 715 static int qos_max_notifier_call(struct notifier_block *nb, 716 unsigned long val, void *ptr) 717 { 718 return qos_notifier_call(container_of(nb, struct devfreq, nb_max)); 719 } 720 721 /** 722 * devfreq_dev_release() - Callback for struct device to release the device. 723 * @dev: the devfreq device 724 * 725 * Remove devfreq from the list and release its resources. 726 */ 727 static void devfreq_dev_release(struct device *dev) 728 { 729 struct devfreq *devfreq = to_devfreq(dev); 730 int err; 731 732 mutex_lock(&devfreq_list_lock); 733 list_del(&devfreq->node); 734 mutex_unlock(&devfreq_list_lock); 735 736 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max, 737 DEV_PM_QOS_MAX_FREQUENCY); 738 if (err && err != -ENOENT) 739 dev_warn(dev->parent, 740 "Failed to remove max_freq notifier: %d\n", err); 741 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min, 742 DEV_PM_QOS_MIN_FREQUENCY); 743 if (err && err != -ENOENT) 744 dev_warn(dev->parent, 745 "Failed to remove min_freq notifier: %d\n", err); 746 747 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { 748 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); 749 if (err < 0) 750 dev_warn(dev->parent, 751 "Failed to remove max_freq request: %d\n", err); 752 } 753 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { 754 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); 755 if (err < 0) 756 dev_warn(dev->parent, 757 "Failed to remove min_freq request: %d\n", err); 758 } 759 760 if (devfreq->profile->exit) 761 devfreq->profile->exit(devfreq->dev.parent); 762 763 if (devfreq->opp_table) 764 dev_pm_opp_put_opp_table(devfreq->opp_table); 765 766 mutex_destroy(&devfreq->lock); 767 srcu_cleanup_notifier_head(&devfreq->transition_notifier_list); 768 kfree(devfreq); 769 } 770 771 static void create_sysfs_files(struct devfreq *devfreq, 772 const struct devfreq_governor *gov); 773 static void remove_sysfs_files(struct devfreq *devfreq, 774 const struct devfreq_governor *gov); 775 776 /** 777 * devfreq_add_device() - Add devfreq feature to the device 778 * @dev: the device to add devfreq feature. 779 * @profile: device-specific profile to run devfreq. 780 * @governor_name: name of the policy to choose frequency. 781 * @data: devfreq driver pass to governors, governor should not change it. 782 */ 783 struct devfreq *devfreq_add_device(struct device *dev, 784 struct devfreq_dev_profile *profile, 785 const char *governor_name, 786 void *data) 787 { 788 struct devfreq *devfreq; 789 struct devfreq_governor *governor; 790 unsigned long min_freq, max_freq; 791 int err = 0; 792 793 if (!dev || !profile || !governor_name) { 794 dev_err(dev, "%s: Invalid parameters.\n", __func__); 795 return ERR_PTR(-EINVAL); 796 } 797 798 mutex_lock(&devfreq_list_lock); 799 devfreq = find_device_devfreq(dev); 800 mutex_unlock(&devfreq_list_lock); 801 if (!IS_ERR(devfreq)) { 802 dev_err(dev, "%s: devfreq device already exists!\n", 803 __func__); 804 err = -EINVAL; 805 goto err_out; 806 } 807 808 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); 809 if (!devfreq) { 810 err = -ENOMEM; 811 goto err_out; 812 } 813 814 mutex_init(&devfreq->lock); 815 mutex_lock(&devfreq->lock); 816 devfreq->dev.parent = dev; 817 devfreq->dev.class = devfreq_class; 818 devfreq->dev.release = devfreq_dev_release; 819 INIT_LIST_HEAD(&devfreq->node); 820 devfreq->profile = profile; 821 devfreq->previous_freq = profile->initial_freq; 822 devfreq->last_status.current_frequency = profile->initial_freq; 823 devfreq->data = data; 824 devfreq->nb.notifier_call = devfreq_notifier_call; 825 826 if (devfreq->profile->timer < 0 827 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) { 828 mutex_unlock(&devfreq->lock); 829 err = -EINVAL; 830 goto err_dev; 831 } 832 833 if (!devfreq->profile->max_state || !devfreq->profile->freq_table) { 834 mutex_unlock(&devfreq->lock); 835 err = set_freq_table(devfreq); 836 if (err < 0) 837 goto err_dev; 838 mutex_lock(&devfreq->lock); 839 } else { 840 devfreq->freq_table = devfreq->profile->freq_table; 841 devfreq->max_state = devfreq->profile->max_state; 842 } 843 844 devfreq->scaling_min_freq = find_available_min_freq(devfreq); 845 if (!devfreq->scaling_min_freq) { 846 mutex_unlock(&devfreq->lock); 847 err = -EINVAL; 848 goto err_dev; 849 } 850 851 devfreq->scaling_max_freq = find_available_max_freq(devfreq); 852 if (!devfreq->scaling_max_freq) { 853 mutex_unlock(&devfreq->lock); 854 err = -EINVAL; 855 goto err_dev; 856 } 857 858 devfreq_get_freq_range(devfreq, &min_freq, &max_freq); 859 860 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); 861 devfreq->opp_table = dev_pm_opp_get_opp_table(dev); 862 if (IS_ERR(devfreq->opp_table)) 863 devfreq->opp_table = NULL; 864 865 atomic_set(&devfreq->suspend_count, 0); 866 867 dev_set_name(&devfreq->dev, "%s", dev_name(dev)); 868 err = device_register(&devfreq->dev); 869 if (err) { 870 mutex_unlock(&devfreq->lock); 871 put_device(&devfreq->dev); 872 goto err_out; 873 } 874 875 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev, 876 array3_size(sizeof(unsigned int), 877 devfreq->max_state, 878 devfreq->max_state), 879 GFP_KERNEL); 880 if (!devfreq->stats.trans_table) { 881 mutex_unlock(&devfreq->lock); 882 err = -ENOMEM; 883 goto err_devfreq; 884 } 885 886 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev, 887 devfreq->max_state, 888 sizeof(*devfreq->stats.time_in_state), 889 GFP_KERNEL); 890 if (!devfreq->stats.time_in_state) { 891 mutex_unlock(&devfreq->lock); 892 err = -ENOMEM; 893 goto err_devfreq; 894 } 895 896 devfreq->stats.total_trans = 0; 897 devfreq->stats.last_update = get_jiffies_64(); 898 899 srcu_init_notifier_head(&devfreq->transition_notifier_list); 900 901 mutex_unlock(&devfreq->lock); 902 903 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, 904 DEV_PM_QOS_MIN_FREQUENCY, 0); 905 if (err < 0) 906 goto err_devfreq; 907 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, 908 DEV_PM_QOS_MAX_FREQUENCY, 909 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); 910 if (err < 0) 911 goto err_devfreq; 912 913 devfreq->nb_min.notifier_call = qos_min_notifier_call; 914 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min, 915 DEV_PM_QOS_MIN_FREQUENCY); 916 if (err) 917 goto err_devfreq; 918 919 devfreq->nb_max.notifier_call = qos_max_notifier_call; 920 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max, 921 DEV_PM_QOS_MAX_FREQUENCY); 922 if (err) 923 goto err_devfreq; 924 925 mutex_lock(&devfreq_list_lock); 926 927 governor = try_then_request_governor(governor_name); 928 if (IS_ERR(governor)) { 929 dev_err(dev, "%s: Unable to find governor for the device\n", 930 __func__); 931 err = PTR_ERR(governor); 932 goto err_init; 933 } 934 935 devfreq->governor = governor; 936 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START, 937 NULL); 938 if (err) { 939 dev_err_probe(dev, err, 940 "%s: Unable to start governor for the device\n", 941 __func__); 942 goto err_init; 943 } 944 create_sysfs_files(devfreq, devfreq->governor); 945 946 list_add(&devfreq->node, &devfreq_list); 947 948 mutex_unlock(&devfreq_list_lock); 949 950 if (devfreq->profile->is_cooling_device) { 951 devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL); 952 if (IS_ERR(devfreq->cdev)) 953 devfreq->cdev = NULL; 954 } 955 956 return devfreq; 957 958 err_init: 959 mutex_unlock(&devfreq_list_lock); 960 err_devfreq: 961 devfreq_remove_device(devfreq); 962 devfreq = NULL; 963 err_dev: 964 kfree(devfreq); 965 err_out: 966 return ERR_PTR(err); 967 } 968 EXPORT_SYMBOL(devfreq_add_device); 969 970 /** 971 * devfreq_remove_device() - Remove devfreq feature from a device. 972 * @devfreq: the devfreq instance to be removed 973 * 974 * The opposite of devfreq_add_device(). 975 */ 976 int devfreq_remove_device(struct devfreq *devfreq) 977 { 978 if (!devfreq) 979 return -EINVAL; 980 981 devfreq_cooling_unregister(devfreq->cdev); 982 983 if (devfreq->governor) { 984 devfreq->governor->event_handler(devfreq, 985 DEVFREQ_GOV_STOP, NULL); 986 remove_sysfs_files(devfreq, devfreq->governor); 987 } 988 989 device_unregister(&devfreq->dev); 990 991 return 0; 992 } 993 EXPORT_SYMBOL(devfreq_remove_device); 994 995 static int devm_devfreq_dev_match(struct device *dev, void *res, void *data) 996 { 997 struct devfreq **r = res; 998 999 if (WARN_ON(!r || !*r)) 1000 return 0; 1001 1002 return *r == data; 1003 } 1004 1005 static void devm_devfreq_dev_release(struct device *dev, void *res) 1006 { 1007 devfreq_remove_device(*(struct devfreq **)res); 1008 } 1009 1010 /** 1011 * devm_devfreq_add_device() - Resource-managed devfreq_add_device() 1012 * @dev: the device to add devfreq feature. 1013 * @profile: device-specific profile to run devfreq. 1014 * @governor_name: name of the policy to choose frequency. 1015 * @data: devfreq driver pass to governors, governor should not change it. 1016 * 1017 * This function manages automatically the memory of devfreq device using device 1018 * resource management and simplify the free operation for memory of devfreq 1019 * device. 1020 */ 1021 struct devfreq *devm_devfreq_add_device(struct device *dev, 1022 struct devfreq_dev_profile *profile, 1023 const char *governor_name, 1024 void *data) 1025 { 1026 struct devfreq **ptr, *devfreq; 1027 1028 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL); 1029 if (!ptr) 1030 return ERR_PTR(-ENOMEM); 1031 1032 devfreq = devfreq_add_device(dev, profile, governor_name, data); 1033 if (IS_ERR(devfreq)) { 1034 devres_free(ptr); 1035 return devfreq; 1036 } 1037 1038 *ptr = devfreq; 1039 devres_add(dev, ptr); 1040 1041 return devfreq; 1042 } 1043 EXPORT_SYMBOL(devm_devfreq_add_device); 1044 1045 #ifdef CONFIG_OF 1046 /* 1047 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree 1048 * @node - pointer to device_node 1049 * 1050 * return the instance of devfreq device 1051 */ 1052 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 1053 { 1054 struct devfreq *devfreq; 1055 1056 if (!node) 1057 return ERR_PTR(-EINVAL); 1058 1059 mutex_lock(&devfreq_list_lock); 1060 list_for_each_entry(devfreq, &devfreq_list, node) { 1061 if (devfreq->dev.parent 1062 && device_match_of_node(devfreq->dev.parent, node)) { 1063 mutex_unlock(&devfreq_list_lock); 1064 return devfreq; 1065 } 1066 } 1067 mutex_unlock(&devfreq_list_lock); 1068 1069 return ERR_PTR(-ENODEV); 1070 } 1071 1072 /* 1073 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree 1074 * @dev - instance to the given device 1075 * @phandle_name - name of property holding a phandle value 1076 * @index - index into list of devfreq 1077 * 1078 * return the instance of devfreq device 1079 */ 1080 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 1081 const char *phandle_name, int index) 1082 { 1083 struct device_node *node; 1084 struct devfreq *devfreq; 1085 1086 if (!dev || !phandle_name) 1087 return ERR_PTR(-EINVAL); 1088 1089 if (!dev->of_node) 1090 return ERR_PTR(-EINVAL); 1091 1092 node = of_parse_phandle(dev->of_node, phandle_name, index); 1093 if (!node) 1094 return ERR_PTR(-ENODEV); 1095 1096 devfreq = devfreq_get_devfreq_by_node(node); 1097 of_node_put(node); 1098 1099 return devfreq; 1100 } 1101 1102 #else 1103 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 1104 { 1105 return ERR_PTR(-ENODEV); 1106 } 1107 1108 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 1109 const char *phandle_name, int index) 1110 { 1111 return ERR_PTR(-ENODEV); 1112 } 1113 #endif /* CONFIG_OF */ 1114 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node); 1115 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle); 1116 1117 /** 1118 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device() 1119 * @dev: the device from which to remove devfreq feature. 1120 * @devfreq: the devfreq instance to be removed 1121 */ 1122 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq) 1123 { 1124 WARN_ON(devres_release(dev, devm_devfreq_dev_release, 1125 devm_devfreq_dev_match, devfreq)); 1126 } 1127 EXPORT_SYMBOL(devm_devfreq_remove_device); 1128 1129 /** 1130 * devfreq_suspend_device() - Suspend devfreq of a device. 1131 * @devfreq: the devfreq instance to be suspended 1132 * 1133 * This function is intended to be called by the pm callbacks 1134 * (e.g., runtime_suspend, suspend) of the device driver that 1135 * holds the devfreq. 1136 */ 1137 int devfreq_suspend_device(struct devfreq *devfreq) 1138 { 1139 int ret; 1140 1141 if (!devfreq) 1142 return -EINVAL; 1143 1144 if (atomic_inc_return(&devfreq->suspend_count) > 1) 1145 return 0; 1146 1147 if (devfreq->governor) { 1148 ret = devfreq->governor->event_handler(devfreq, 1149 DEVFREQ_GOV_SUSPEND, NULL); 1150 if (ret) 1151 return ret; 1152 } 1153 1154 if (devfreq->suspend_freq) { 1155 mutex_lock(&devfreq->lock); 1156 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0); 1157 mutex_unlock(&devfreq->lock); 1158 if (ret) 1159 return ret; 1160 } 1161 1162 return 0; 1163 } 1164 EXPORT_SYMBOL(devfreq_suspend_device); 1165 1166 /** 1167 * devfreq_resume_device() - Resume devfreq of a device. 1168 * @devfreq: the devfreq instance to be resumed 1169 * 1170 * This function is intended to be called by the pm callbacks 1171 * (e.g., runtime_resume, resume) of the device driver that 1172 * holds the devfreq. 1173 */ 1174 int devfreq_resume_device(struct devfreq *devfreq) 1175 { 1176 int ret; 1177 1178 if (!devfreq) 1179 return -EINVAL; 1180 1181 if (atomic_dec_return(&devfreq->suspend_count) >= 1) 1182 return 0; 1183 1184 if (devfreq->resume_freq) { 1185 mutex_lock(&devfreq->lock); 1186 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0); 1187 mutex_unlock(&devfreq->lock); 1188 if (ret) 1189 return ret; 1190 } 1191 1192 if (devfreq->governor) { 1193 ret = devfreq->governor->event_handler(devfreq, 1194 DEVFREQ_GOV_RESUME, NULL); 1195 if (ret) 1196 return ret; 1197 } 1198 1199 return 0; 1200 } 1201 EXPORT_SYMBOL(devfreq_resume_device); 1202 1203 /** 1204 * devfreq_suspend() - Suspend devfreq governors and devices 1205 * 1206 * Called during system wide Suspend/Hibernate cycles for suspending governors 1207 * and devices preserving the state for resume. On some platforms the devfreq 1208 * device must have precise state (frequency) after resume in order to provide 1209 * fully operating setup. 1210 */ 1211 void devfreq_suspend(void) 1212 { 1213 struct devfreq *devfreq; 1214 int ret; 1215 1216 mutex_lock(&devfreq_list_lock); 1217 list_for_each_entry(devfreq, &devfreq_list, node) { 1218 ret = devfreq_suspend_device(devfreq); 1219 if (ret) 1220 dev_err(&devfreq->dev, 1221 "failed to suspend devfreq device\n"); 1222 } 1223 mutex_unlock(&devfreq_list_lock); 1224 } 1225 1226 /** 1227 * devfreq_resume() - Resume devfreq governors and devices 1228 * 1229 * Called during system wide Suspend/Hibernate cycle for resuming governors and 1230 * devices that are suspended with devfreq_suspend(). 1231 */ 1232 void devfreq_resume(void) 1233 { 1234 struct devfreq *devfreq; 1235 int ret; 1236 1237 mutex_lock(&devfreq_list_lock); 1238 list_for_each_entry(devfreq, &devfreq_list, node) { 1239 ret = devfreq_resume_device(devfreq); 1240 if (ret) 1241 dev_warn(&devfreq->dev, 1242 "failed to resume devfreq device\n"); 1243 } 1244 mutex_unlock(&devfreq_list_lock); 1245 } 1246 1247 /** 1248 * devfreq_add_governor() - Add devfreq governor 1249 * @governor: the devfreq governor to be added 1250 */ 1251 int devfreq_add_governor(struct devfreq_governor *governor) 1252 { 1253 struct devfreq_governor *g; 1254 struct devfreq *devfreq; 1255 int err = 0; 1256 1257 if (!governor) { 1258 pr_err("%s: Invalid parameters.\n", __func__); 1259 return -EINVAL; 1260 } 1261 1262 mutex_lock(&devfreq_list_lock); 1263 g = find_devfreq_governor(governor->name); 1264 if (!IS_ERR(g)) { 1265 pr_err("%s: governor %s already registered\n", __func__, 1266 g->name); 1267 err = -EINVAL; 1268 goto err_out; 1269 } 1270 1271 list_add(&governor->node, &devfreq_governor_list); 1272 1273 list_for_each_entry(devfreq, &devfreq_list, node) { 1274 int ret = 0; 1275 struct device *dev = devfreq->dev.parent; 1276 1277 if (!strncmp(devfreq->governor->name, governor->name, 1278 DEVFREQ_NAME_LEN)) { 1279 /* The following should never occur */ 1280 if (devfreq->governor) { 1281 dev_warn(dev, 1282 "%s: Governor %s already present\n", 1283 __func__, devfreq->governor->name); 1284 ret = devfreq->governor->event_handler(devfreq, 1285 DEVFREQ_GOV_STOP, NULL); 1286 if (ret) { 1287 dev_warn(dev, 1288 "%s: Governor %s stop = %d\n", 1289 __func__, 1290 devfreq->governor->name, ret); 1291 } 1292 /* Fall through */ 1293 } 1294 devfreq->governor = governor; 1295 ret = devfreq->governor->event_handler(devfreq, 1296 DEVFREQ_GOV_START, NULL); 1297 if (ret) { 1298 dev_warn(dev, "%s: Governor %s start=%d\n", 1299 __func__, devfreq->governor->name, 1300 ret); 1301 } 1302 } 1303 } 1304 1305 err_out: 1306 mutex_unlock(&devfreq_list_lock); 1307 1308 return err; 1309 } 1310 EXPORT_SYMBOL(devfreq_add_governor); 1311 1312 static void devm_devfreq_remove_governor(void *governor) 1313 { 1314 WARN_ON(devfreq_remove_governor(governor)); 1315 } 1316 1317 /** 1318 * devm_devfreq_add_governor() - Add devfreq governor 1319 * @dev: device which adds devfreq governor 1320 * @governor: the devfreq governor to be added 1321 * 1322 * This is a resource-managed variant of devfreq_add_governor(). 1323 */ 1324 int devm_devfreq_add_governor(struct device *dev, 1325 struct devfreq_governor *governor) 1326 { 1327 int err; 1328 1329 err = devfreq_add_governor(governor); 1330 if (err) 1331 return err; 1332 1333 return devm_add_action_or_reset(dev, devm_devfreq_remove_governor, 1334 governor); 1335 } 1336 EXPORT_SYMBOL(devm_devfreq_add_governor); 1337 1338 /** 1339 * devfreq_remove_governor() - Remove devfreq feature from a device. 1340 * @governor: the devfreq governor to be removed 1341 */ 1342 int devfreq_remove_governor(struct devfreq_governor *governor) 1343 { 1344 struct devfreq_governor *g; 1345 struct devfreq *devfreq; 1346 int err = 0; 1347 1348 if (!governor) { 1349 pr_err("%s: Invalid parameters.\n", __func__); 1350 return -EINVAL; 1351 } 1352 1353 mutex_lock(&devfreq_list_lock); 1354 g = find_devfreq_governor(governor->name); 1355 if (IS_ERR(g)) { 1356 pr_err("%s: governor %s not registered\n", __func__, 1357 governor->name); 1358 err = PTR_ERR(g); 1359 goto err_out; 1360 } 1361 list_for_each_entry(devfreq, &devfreq_list, node) { 1362 int ret; 1363 struct device *dev = devfreq->dev.parent; 1364 1365 if (!strncmp(devfreq->governor->name, governor->name, 1366 DEVFREQ_NAME_LEN)) { 1367 /* we should have a devfreq governor! */ 1368 if (!devfreq->governor) { 1369 dev_warn(dev, "%s: Governor %s NOT present\n", 1370 __func__, governor->name); 1371 continue; 1372 /* Fall through */ 1373 } 1374 ret = devfreq->governor->event_handler(devfreq, 1375 DEVFREQ_GOV_STOP, NULL); 1376 if (ret) { 1377 dev_warn(dev, "%s: Governor %s stop=%d\n", 1378 __func__, devfreq->governor->name, 1379 ret); 1380 } 1381 devfreq->governor = NULL; 1382 } 1383 } 1384 1385 list_del(&governor->node); 1386 err_out: 1387 mutex_unlock(&devfreq_list_lock); 1388 1389 return err; 1390 } 1391 EXPORT_SYMBOL(devfreq_remove_governor); 1392 1393 static ssize_t name_show(struct device *dev, 1394 struct device_attribute *attr, char *buf) 1395 { 1396 struct devfreq *df = to_devfreq(dev); 1397 return sprintf(buf, "%s\n", dev_name(df->dev.parent)); 1398 } 1399 static DEVICE_ATTR_RO(name); 1400 1401 static ssize_t governor_show(struct device *dev, 1402 struct device_attribute *attr, char *buf) 1403 { 1404 struct devfreq *df = to_devfreq(dev); 1405 1406 if (!df->governor) 1407 return -EINVAL; 1408 1409 return sprintf(buf, "%s\n", df->governor->name); 1410 } 1411 1412 static ssize_t governor_store(struct device *dev, struct device_attribute *attr, 1413 const char *buf, size_t count) 1414 { 1415 struct devfreq *df = to_devfreq(dev); 1416 int ret; 1417 char str_governor[DEVFREQ_NAME_LEN + 1]; 1418 const struct devfreq_governor *governor, *prev_governor; 1419 1420 if (!df->governor) 1421 return -EINVAL; 1422 1423 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); 1424 if (ret != 1) 1425 return -EINVAL; 1426 1427 mutex_lock(&devfreq_list_lock); 1428 governor = try_then_request_governor(str_governor); 1429 if (IS_ERR(governor)) { 1430 ret = PTR_ERR(governor); 1431 goto out; 1432 } 1433 if (df->governor == governor) { 1434 ret = 0; 1435 goto out; 1436 } else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE) 1437 || IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) { 1438 ret = -EINVAL; 1439 goto out; 1440 } 1441 1442 /* 1443 * Stop the current governor and remove the specific sysfs files 1444 * which depend on current governor. 1445 */ 1446 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); 1447 if (ret) { 1448 dev_warn(dev, "%s: Governor %s not stopped(%d)\n", 1449 __func__, df->governor->name, ret); 1450 goto out; 1451 } 1452 remove_sysfs_files(df, df->governor); 1453 1454 /* 1455 * Start the new governor and create the specific sysfs files 1456 * which depend on the new governor. 1457 */ 1458 prev_governor = df->governor; 1459 df->governor = governor; 1460 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1461 if (ret) { 1462 dev_warn(dev, "%s: Governor %s not started(%d)\n", 1463 __func__, df->governor->name, ret); 1464 1465 /* Restore previous governor */ 1466 df->governor = prev_governor; 1467 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1468 if (ret) { 1469 dev_err(dev, 1470 "%s: reverting to Governor %s failed (%d)\n", 1471 __func__, prev_governor->name, ret); 1472 df->governor = NULL; 1473 goto out; 1474 } 1475 } 1476 1477 /* 1478 * Create the sysfs files for the new governor. But if failed to start 1479 * the new governor, restore the sysfs files of previous governor. 1480 */ 1481 create_sysfs_files(df, df->governor); 1482 1483 out: 1484 mutex_unlock(&devfreq_list_lock); 1485 1486 if (!ret) 1487 ret = count; 1488 return ret; 1489 } 1490 static DEVICE_ATTR_RW(governor); 1491 1492 static ssize_t available_governors_show(struct device *d, 1493 struct device_attribute *attr, 1494 char *buf) 1495 { 1496 struct devfreq *df = to_devfreq(d); 1497 ssize_t count = 0; 1498 1499 if (!df->governor) 1500 return -EINVAL; 1501 1502 mutex_lock(&devfreq_list_lock); 1503 1504 /* 1505 * The devfreq with immutable governor (e.g., passive) shows 1506 * only own governor. 1507 */ 1508 if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) { 1509 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN, 1510 "%s ", df->governor->name); 1511 /* 1512 * The devfreq device shows the registered governor except for 1513 * immutable governors such as passive governor . 1514 */ 1515 } else { 1516 struct devfreq_governor *governor; 1517 1518 list_for_each_entry(governor, &devfreq_governor_list, node) { 1519 if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) 1520 continue; 1521 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), 1522 "%s ", governor->name); 1523 } 1524 } 1525 1526 mutex_unlock(&devfreq_list_lock); 1527 1528 /* Truncate the trailing space */ 1529 if (count) 1530 count--; 1531 1532 count += sprintf(&buf[count], "\n"); 1533 1534 return count; 1535 } 1536 static DEVICE_ATTR_RO(available_governors); 1537 1538 static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, 1539 char *buf) 1540 { 1541 unsigned long freq; 1542 struct devfreq *df = to_devfreq(dev); 1543 1544 if (!df->profile) 1545 return -EINVAL; 1546 1547 if (df->profile->get_cur_freq && 1548 !df->profile->get_cur_freq(df->dev.parent, &freq)) 1549 return sprintf(buf, "%lu\n", freq); 1550 1551 return sprintf(buf, "%lu\n", df->previous_freq); 1552 } 1553 static DEVICE_ATTR_RO(cur_freq); 1554 1555 static ssize_t target_freq_show(struct device *dev, 1556 struct device_attribute *attr, char *buf) 1557 { 1558 struct devfreq *df = to_devfreq(dev); 1559 1560 return sprintf(buf, "%lu\n", df->previous_freq); 1561 } 1562 static DEVICE_ATTR_RO(target_freq); 1563 1564 static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, 1565 const char *buf, size_t count) 1566 { 1567 struct devfreq *df = to_devfreq(dev); 1568 unsigned long value; 1569 int ret; 1570 1571 /* 1572 * Protect against theoretical sysfs writes between 1573 * device_add and dev_pm_qos_add_request 1574 */ 1575 if (!dev_pm_qos_request_active(&df->user_min_freq_req)) 1576 return -EAGAIN; 1577 1578 ret = sscanf(buf, "%lu", &value); 1579 if (ret != 1) 1580 return -EINVAL; 1581 1582 /* Round down to kHz for PM QoS */ 1583 ret = dev_pm_qos_update_request(&df->user_min_freq_req, 1584 value / HZ_PER_KHZ); 1585 if (ret < 0) 1586 return ret; 1587 1588 return count; 1589 } 1590 1591 static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, 1592 char *buf) 1593 { 1594 struct devfreq *df = to_devfreq(dev); 1595 unsigned long min_freq, max_freq; 1596 1597 mutex_lock(&df->lock); 1598 devfreq_get_freq_range(df, &min_freq, &max_freq); 1599 mutex_unlock(&df->lock); 1600 1601 return sprintf(buf, "%lu\n", min_freq); 1602 } 1603 static DEVICE_ATTR_RW(min_freq); 1604 1605 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, 1606 const char *buf, size_t count) 1607 { 1608 struct devfreq *df = to_devfreq(dev); 1609 unsigned long value; 1610 int ret; 1611 1612 /* 1613 * Protect against theoretical sysfs writes between 1614 * device_add and dev_pm_qos_add_request 1615 */ 1616 if (!dev_pm_qos_request_active(&df->user_max_freq_req)) 1617 return -EINVAL; 1618 1619 ret = sscanf(buf, "%lu", &value); 1620 if (ret != 1) 1621 return -EINVAL; 1622 1623 /* 1624 * PM QoS frequencies are in kHz so we need to convert. Convert by 1625 * rounding upwards so that the acceptable interval never shrinks. 1626 * 1627 * For example if the user writes "666666666" to sysfs this value will 1628 * be converted to 666667 kHz and back to 666667000 Hz before an OPP 1629 * lookup, this ensures that an OPP of 666666666Hz is still accepted. 1630 * 1631 * A value of zero means "no limit". 1632 */ 1633 if (value) 1634 value = DIV_ROUND_UP(value, HZ_PER_KHZ); 1635 else 1636 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; 1637 1638 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); 1639 if (ret < 0) 1640 return ret; 1641 1642 return count; 1643 } 1644 1645 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, 1646 char *buf) 1647 { 1648 struct devfreq *df = to_devfreq(dev); 1649 unsigned long min_freq, max_freq; 1650 1651 mutex_lock(&df->lock); 1652 devfreq_get_freq_range(df, &min_freq, &max_freq); 1653 mutex_unlock(&df->lock); 1654 1655 return sprintf(buf, "%lu\n", max_freq); 1656 } 1657 static DEVICE_ATTR_RW(max_freq); 1658 1659 static ssize_t available_frequencies_show(struct device *d, 1660 struct device_attribute *attr, 1661 char *buf) 1662 { 1663 struct devfreq *df = to_devfreq(d); 1664 ssize_t count = 0; 1665 int i; 1666 1667 if (!df->profile) 1668 return -EINVAL; 1669 1670 mutex_lock(&df->lock); 1671 1672 for (i = 0; i < df->max_state; i++) 1673 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), 1674 "%lu ", df->freq_table[i]); 1675 1676 mutex_unlock(&df->lock); 1677 /* Truncate the trailing space */ 1678 if (count) 1679 count--; 1680 1681 count += sprintf(&buf[count], "\n"); 1682 1683 return count; 1684 } 1685 static DEVICE_ATTR_RO(available_frequencies); 1686 1687 static ssize_t trans_stat_show(struct device *dev, 1688 struct device_attribute *attr, char *buf) 1689 { 1690 struct devfreq *df = to_devfreq(dev); 1691 ssize_t len; 1692 int i, j; 1693 unsigned int max_state; 1694 1695 if (!df->profile) 1696 return -EINVAL; 1697 max_state = df->max_state; 1698 1699 if (max_state == 0) 1700 return sprintf(buf, "Not Supported.\n"); 1701 1702 mutex_lock(&df->lock); 1703 if (!df->stop_polling && 1704 devfreq_update_status(df, df->previous_freq)) { 1705 mutex_unlock(&df->lock); 1706 return 0; 1707 } 1708 mutex_unlock(&df->lock); 1709 1710 len = sprintf(buf, " From : To\n"); 1711 len += sprintf(buf + len, " :"); 1712 for (i = 0; i < max_state; i++) 1713 len += sprintf(buf + len, "%10lu", 1714 df->freq_table[i]); 1715 1716 len += sprintf(buf + len, " time(ms)\n"); 1717 1718 for (i = 0; i < max_state; i++) { 1719 if (df->freq_table[i] == df->previous_freq) 1720 len += sprintf(buf + len, "*"); 1721 else 1722 len += sprintf(buf + len, " "); 1723 1724 len += sprintf(buf + len, "%10lu:", df->freq_table[i]); 1725 for (j = 0; j < max_state; j++) 1726 len += sprintf(buf + len, "%10u", 1727 df->stats.trans_table[(i * max_state) + j]); 1728 1729 len += sprintf(buf + len, "%10llu\n", (u64) 1730 jiffies64_to_msecs(df->stats.time_in_state[i])); 1731 } 1732 1733 len += sprintf(buf + len, "Total transition : %u\n", 1734 df->stats.total_trans); 1735 return len; 1736 } 1737 1738 static ssize_t trans_stat_store(struct device *dev, 1739 struct device_attribute *attr, 1740 const char *buf, size_t count) 1741 { 1742 struct devfreq *df = to_devfreq(dev); 1743 int err, value; 1744 1745 if (!df->profile) 1746 return -EINVAL; 1747 1748 if (df->max_state == 0) 1749 return count; 1750 1751 err = kstrtoint(buf, 10, &value); 1752 if (err || value != 0) 1753 return -EINVAL; 1754 1755 mutex_lock(&df->lock); 1756 memset(df->stats.time_in_state, 0, (df->max_state * 1757 sizeof(*df->stats.time_in_state))); 1758 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int), 1759 df->max_state, 1760 df->max_state)); 1761 df->stats.total_trans = 0; 1762 df->stats.last_update = get_jiffies_64(); 1763 mutex_unlock(&df->lock); 1764 1765 return count; 1766 } 1767 static DEVICE_ATTR_RW(trans_stat); 1768 1769 static struct attribute *devfreq_attrs[] = { 1770 &dev_attr_name.attr, 1771 &dev_attr_governor.attr, 1772 &dev_attr_available_governors.attr, 1773 &dev_attr_cur_freq.attr, 1774 &dev_attr_available_frequencies.attr, 1775 &dev_attr_target_freq.attr, 1776 &dev_attr_min_freq.attr, 1777 &dev_attr_max_freq.attr, 1778 &dev_attr_trans_stat.attr, 1779 NULL, 1780 }; 1781 ATTRIBUTE_GROUPS(devfreq); 1782 1783 static ssize_t polling_interval_show(struct device *dev, 1784 struct device_attribute *attr, char *buf) 1785 { 1786 struct devfreq *df = to_devfreq(dev); 1787 1788 if (!df->profile) 1789 return -EINVAL; 1790 1791 return sprintf(buf, "%d\n", df->profile->polling_ms); 1792 } 1793 1794 static ssize_t polling_interval_store(struct device *dev, 1795 struct device_attribute *attr, 1796 const char *buf, size_t count) 1797 { 1798 struct devfreq *df = to_devfreq(dev); 1799 unsigned int value; 1800 int ret; 1801 1802 if (!df->governor) 1803 return -EINVAL; 1804 1805 ret = sscanf(buf, "%u", &value); 1806 if (ret != 1) 1807 return -EINVAL; 1808 1809 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value); 1810 ret = count; 1811 1812 return ret; 1813 } 1814 static DEVICE_ATTR_RW(polling_interval); 1815 1816 static ssize_t timer_show(struct device *dev, 1817 struct device_attribute *attr, char *buf) 1818 { 1819 struct devfreq *df = to_devfreq(dev); 1820 1821 if (!df->profile) 1822 return -EINVAL; 1823 1824 return sprintf(buf, "%s\n", timer_name[df->profile->timer]); 1825 } 1826 1827 static ssize_t timer_store(struct device *dev, struct device_attribute *attr, 1828 const char *buf, size_t count) 1829 { 1830 struct devfreq *df = to_devfreq(dev); 1831 char str_timer[DEVFREQ_NAME_LEN + 1]; 1832 int timer = -1; 1833 int ret = 0, i; 1834 1835 if (!df->governor || !df->profile) 1836 return -EINVAL; 1837 1838 ret = sscanf(buf, "%16s", str_timer); 1839 if (ret != 1) 1840 return -EINVAL; 1841 1842 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) { 1843 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) { 1844 timer = i; 1845 break; 1846 } 1847 } 1848 1849 if (timer < 0) { 1850 ret = -EINVAL; 1851 goto out; 1852 } 1853 1854 if (df->profile->timer == timer) { 1855 ret = 0; 1856 goto out; 1857 } 1858 1859 mutex_lock(&df->lock); 1860 df->profile->timer = timer; 1861 mutex_unlock(&df->lock); 1862 1863 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); 1864 if (ret) { 1865 dev_warn(dev, "%s: Governor %s not stopped(%d)\n", 1866 __func__, df->governor->name, ret); 1867 goto out; 1868 } 1869 1870 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1871 if (ret) 1872 dev_warn(dev, "%s: Governor %s not started(%d)\n", 1873 __func__, df->governor->name, ret); 1874 out: 1875 return ret ? ret : count; 1876 } 1877 static DEVICE_ATTR_RW(timer); 1878 1879 #define CREATE_SYSFS_FILE(df, name) \ 1880 { \ 1881 int ret; \ 1882 ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \ 1883 if (ret < 0) { \ 1884 dev_warn(&df->dev, \ 1885 "Unable to create attr(%s)\n", "##name"); \ 1886 } \ 1887 } \ 1888 1889 /* Create the specific sysfs files which depend on each governor. */ 1890 static void create_sysfs_files(struct devfreq *devfreq, 1891 const struct devfreq_governor *gov) 1892 { 1893 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL)) 1894 CREATE_SYSFS_FILE(devfreq, polling_interval); 1895 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER)) 1896 CREATE_SYSFS_FILE(devfreq, timer); 1897 } 1898 1899 /* Remove the specific sysfs files which depend on each governor. */ 1900 static void remove_sysfs_files(struct devfreq *devfreq, 1901 const struct devfreq_governor *gov) 1902 { 1903 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL)) 1904 sysfs_remove_file(&devfreq->dev.kobj, 1905 &dev_attr_polling_interval.attr); 1906 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER)) 1907 sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr); 1908 } 1909 1910 /** 1911 * devfreq_summary_show() - Show the summary of the devfreq devices 1912 * @s: seq_file instance to show the summary of devfreq devices 1913 * @data: not used 1914 * 1915 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. 1916 * It helps that user can know the detailed information of the devfreq devices. 1917 * 1918 * Return 0 always because it shows the information without any data change. 1919 */ 1920 static int devfreq_summary_show(struct seq_file *s, void *data) 1921 { 1922 struct devfreq *devfreq; 1923 struct devfreq *p_devfreq = NULL; 1924 unsigned long cur_freq, min_freq, max_freq; 1925 unsigned int polling_ms; 1926 unsigned int timer; 1927 1928 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n", 1929 "dev", 1930 "parent_dev", 1931 "governor", 1932 "timer", 1933 "polling_ms", 1934 "cur_freq_Hz", 1935 "min_freq_Hz", 1936 "max_freq_Hz"); 1937 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n", 1938 "------------------------------", 1939 "------------------------------", 1940 "---------------", 1941 "----------", 1942 "----------", 1943 "------------", 1944 "------------", 1945 "------------"); 1946 1947 mutex_lock(&devfreq_list_lock); 1948 1949 list_for_each_entry_reverse(devfreq, &devfreq_list, node) { 1950 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) 1951 if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE, 1952 DEVFREQ_NAME_LEN)) { 1953 struct devfreq_passive_data *data = devfreq->data; 1954 1955 if (data) 1956 p_devfreq = data->parent; 1957 } else { 1958 p_devfreq = NULL; 1959 } 1960 #endif 1961 1962 mutex_lock(&devfreq->lock); 1963 cur_freq = devfreq->previous_freq; 1964 devfreq_get_freq_range(devfreq, &min_freq, &max_freq); 1965 timer = devfreq->profile->timer; 1966 1967 if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL)) 1968 polling_ms = devfreq->profile->polling_ms; 1969 else 1970 polling_ms = 0; 1971 mutex_unlock(&devfreq->lock); 1972 1973 seq_printf(s, 1974 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n", 1975 dev_name(&devfreq->dev), 1976 p_devfreq ? dev_name(&p_devfreq->dev) : "null", 1977 devfreq->governor->name, 1978 polling_ms ? timer_name[timer] : "null", 1979 polling_ms, 1980 cur_freq, 1981 min_freq, 1982 max_freq); 1983 } 1984 1985 mutex_unlock(&devfreq_list_lock); 1986 1987 return 0; 1988 } 1989 DEFINE_SHOW_ATTRIBUTE(devfreq_summary); 1990 1991 static int __init devfreq_init(void) 1992 { 1993 devfreq_class = class_create("devfreq"); 1994 if (IS_ERR(devfreq_class)) { 1995 pr_err("%s: couldn't create class\n", __FILE__); 1996 return PTR_ERR(devfreq_class); 1997 } 1998 1999 devfreq_wq = create_freezable_workqueue("devfreq_wq"); 2000 if (!devfreq_wq) { 2001 class_destroy(devfreq_class); 2002 pr_err("%s: couldn't create workqueue\n", __FILE__); 2003 return -ENOMEM; 2004 } 2005 devfreq_class->dev_groups = devfreq_groups; 2006 2007 devfreq_debugfs = debugfs_create_dir("devfreq", NULL); 2008 debugfs_create_file("devfreq_summary", 0444, 2009 devfreq_debugfs, NULL, 2010 &devfreq_summary_fops); 2011 2012 return 0; 2013 } 2014 subsys_initcall(devfreq_init); 2015 2016 /* 2017 * The following are helper functions for devfreq user device drivers with 2018 * OPP framework. 2019 */ 2020 2021 /** 2022 * devfreq_recommended_opp() - Helper function to get proper OPP for the 2023 * freq value given to target callback. 2024 * @dev: The devfreq user device. (parent of devfreq) 2025 * @freq: The frequency given to target function 2026 * @flags: Flags handed from devfreq framework. 2027 * 2028 * The callers are required to call dev_pm_opp_put() for the returned OPP after 2029 * use. 2030 */ 2031 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, 2032 unsigned long *freq, 2033 u32 flags) 2034 { 2035 struct dev_pm_opp *opp; 2036 2037 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { 2038 /* The freq is an upper bound. opp should be lower */ 2039 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0); 2040 2041 /* If not available, use the closest opp */ 2042 if (opp == ERR_PTR(-ERANGE)) 2043 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0); 2044 } else { 2045 /* The freq is an lower bound. opp should be higher */ 2046 opp = dev_pm_opp_find_freq_ceil_indexed(dev, freq, 0); 2047 2048 /* If not available, use the closest opp */ 2049 if (opp == ERR_PTR(-ERANGE)) 2050 opp = dev_pm_opp_find_freq_floor_indexed(dev, freq, 0); 2051 } 2052 2053 return opp; 2054 } 2055 EXPORT_SYMBOL(devfreq_recommended_opp); 2056 2057 /** 2058 * devfreq_register_opp_notifier() - Helper function to get devfreq notified 2059 * for any changes in the OPP availability 2060 * changes 2061 * @dev: The devfreq user device. (parent of devfreq) 2062 * @devfreq: The devfreq object. 2063 */ 2064 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) 2065 { 2066 return dev_pm_opp_register_notifier(dev, &devfreq->nb); 2067 } 2068 EXPORT_SYMBOL(devfreq_register_opp_notifier); 2069 2070 /** 2071 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq 2072 * notified for any changes in the OPP 2073 * availability changes anymore. 2074 * @dev: The devfreq user device. (parent of devfreq) 2075 * @devfreq: The devfreq object. 2076 * 2077 * At exit() callback of devfreq_dev_profile, this must be included if 2078 * devfreq_recommended_opp is used. 2079 */ 2080 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) 2081 { 2082 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb); 2083 } 2084 EXPORT_SYMBOL(devfreq_unregister_opp_notifier); 2085 2086 static void devm_devfreq_opp_release(struct device *dev, void *res) 2087 { 2088 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res); 2089 } 2090 2091 /** 2092 * devm_devfreq_register_opp_notifier() - Resource-managed 2093 * devfreq_register_opp_notifier() 2094 * @dev: The devfreq user device. (parent of devfreq) 2095 * @devfreq: The devfreq object. 2096 */ 2097 int devm_devfreq_register_opp_notifier(struct device *dev, 2098 struct devfreq *devfreq) 2099 { 2100 struct devfreq **ptr; 2101 int ret; 2102 2103 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL); 2104 if (!ptr) 2105 return -ENOMEM; 2106 2107 ret = devfreq_register_opp_notifier(dev, devfreq); 2108 if (ret) { 2109 devres_free(ptr); 2110 return ret; 2111 } 2112 2113 *ptr = devfreq; 2114 devres_add(dev, ptr); 2115 2116 return 0; 2117 } 2118 EXPORT_SYMBOL(devm_devfreq_register_opp_notifier); 2119 2120 /** 2121 * devm_devfreq_unregister_opp_notifier() - Resource-managed 2122 * devfreq_unregister_opp_notifier() 2123 * @dev: The devfreq user device. (parent of devfreq) 2124 * @devfreq: The devfreq object. 2125 */ 2126 void devm_devfreq_unregister_opp_notifier(struct device *dev, 2127 struct devfreq *devfreq) 2128 { 2129 WARN_ON(devres_release(dev, devm_devfreq_opp_release, 2130 devm_devfreq_dev_match, devfreq)); 2131 } 2132 EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier); 2133 2134 /** 2135 * devfreq_register_notifier() - Register a driver with devfreq 2136 * @devfreq: The devfreq object. 2137 * @nb: The notifier block to register. 2138 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2139 */ 2140 int devfreq_register_notifier(struct devfreq *devfreq, 2141 struct notifier_block *nb, 2142 unsigned int list) 2143 { 2144 int ret = 0; 2145 2146 if (!devfreq) 2147 return -EINVAL; 2148 2149 switch (list) { 2150 case DEVFREQ_TRANSITION_NOTIFIER: 2151 ret = srcu_notifier_chain_register( 2152 &devfreq->transition_notifier_list, nb); 2153 break; 2154 default: 2155 ret = -EINVAL; 2156 } 2157 2158 return ret; 2159 } 2160 EXPORT_SYMBOL(devfreq_register_notifier); 2161 2162 /* 2163 * devfreq_unregister_notifier() - Unregister a driver with devfreq 2164 * @devfreq: The devfreq object. 2165 * @nb: The notifier block to be unregistered. 2166 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2167 */ 2168 int devfreq_unregister_notifier(struct devfreq *devfreq, 2169 struct notifier_block *nb, 2170 unsigned int list) 2171 { 2172 int ret = 0; 2173 2174 if (!devfreq) 2175 return -EINVAL; 2176 2177 switch (list) { 2178 case DEVFREQ_TRANSITION_NOTIFIER: 2179 ret = srcu_notifier_chain_unregister( 2180 &devfreq->transition_notifier_list, nb); 2181 break; 2182 default: 2183 ret = -EINVAL; 2184 } 2185 2186 return ret; 2187 } 2188 EXPORT_SYMBOL(devfreq_unregister_notifier); 2189 2190 struct devfreq_notifier_devres { 2191 struct devfreq *devfreq; 2192 struct notifier_block *nb; 2193 unsigned int list; 2194 }; 2195 2196 static void devm_devfreq_notifier_release(struct device *dev, void *res) 2197 { 2198 struct devfreq_notifier_devres *this = res; 2199 2200 devfreq_unregister_notifier(this->devfreq, this->nb, this->list); 2201 } 2202 2203 /** 2204 * devm_devfreq_register_notifier() 2205 * - Resource-managed devfreq_register_notifier() 2206 * @dev: The devfreq user device. (parent of devfreq) 2207 * @devfreq: The devfreq object. 2208 * @nb: The notifier block to be unregistered. 2209 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2210 */ 2211 int devm_devfreq_register_notifier(struct device *dev, 2212 struct devfreq *devfreq, 2213 struct notifier_block *nb, 2214 unsigned int list) 2215 { 2216 struct devfreq_notifier_devres *ptr; 2217 int ret; 2218 2219 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr), 2220 GFP_KERNEL); 2221 if (!ptr) 2222 return -ENOMEM; 2223 2224 ret = devfreq_register_notifier(devfreq, nb, list); 2225 if (ret) { 2226 devres_free(ptr); 2227 return ret; 2228 } 2229 2230 ptr->devfreq = devfreq; 2231 ptr->nb = nb; 2232 ptr->list = list; 2233 devres_add(dev, ptr); 2234 2235 return 0; 2236 } 2237 EXPORT_SYMBOL(devm_devfreq_register_notifier); 2238 2239 /** 2240 * devm_devfreq_unregister_notifier() 2241 * - Resource-managed devfreq_unregister_notifier() 2242 * @dev: The devfreq user device. (parent of devfreq) 2243 * @devfreq: The devfreq object. 2244 * @nb: The notifier block to be unregistered. 2245 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2246 */ 2247 void devm_devfreq_unregister_notifier(struct device *dev, 2248 struct devfreq *devfreq, 2249 struct notifier_block *nb, 2250 unsigned int list) 2251 { 2252 WARN_ON(devres_release(dev, devm_devfreq_notifier_release, 2253 devm_devfreq_dev_match, devfreq)); 2254 } 2255 EXPORT_SYMBOL(devm_devfreq_unregister_notifier); 2256