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(devfreq->dev.parent, &min_freq); 92 if (IS_ERR(opp)) 93 min_freq = 0; 94 else 95 dev_pm_opp_put(opp); 96 97 return min_freq; 98 } 99 100 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(devfreq->dev.parent, &max_freq); 106 if (IS_ERR(opp)) 107 max_freq = 0; 108 else 109 dev_pm_opp_put(opp); 110 111 return max_freq; 112 } 113 114 /** 115 * 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(devfreq->dev.parent, &freq); 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 476 * default delayed work based monitoring is supported. Function 477 * to be called from governor in response to DEVFREQ_GOV_START 478 * event when device is added to devfreq framework. 479 */ 480 void devfreq_monitor_start(struct devfreq *devfreq) 481 { 482 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 483 return; 484 485 switch (devfreq->profile->timer) { 486 case DEVFREQ_TIMER_DEFERRABLE: 487 INIT_DEFERRABLE_WORK(&devfreq->work, devfreq_monitor); 488 break; 489 case DEVFREQ_TIMER_DELAYED: 490 INIT_DELAYED_WORK(&devfreq->work, devfreq_monitor); 491 break; 492 default: 493 return; 494 } 495 496 if (devfreq->profile->polling_ms) 497 queue_delayed_work(devfreq_wq, &devfreq->work, 498 msecs_to_jiffies(devfreq->profile->polling_ms)); 499 } 500 EXPORT_SYMBOL(devfreq_monitor_start); 501 502 /** 503 * devfreq_monitor_stop() - Stop load monitoring of a devfreq instance 504 * @devfreq: the devfreq instance. 505 * 506 * Helper function to stop devfreq device load monitoring. Function 507 * to be called from governor in response to DEVFREQ_GOV_STOP 508 * event when device is removed from devfreq framework. 509 */ 510 void devfreq_monitor_stop(struct devfreq *devfreq) 511 { 512 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 513 return; 514 515 cancel_delayed_work_sync(&devfreq->work); 516 } 517 EXPORT_SYMBOL(devfreq_monitor_stop); 518 519 /** 520 * devfreq_monitor_suspend() - Suspend load monitoring of a devfreq instance 521 * @devfreq: the devfreq instance. 522 * 523 * Helper function to suspend devfreq device load monitoring. Function 524 * to be called from governor in response to DEVFREQ_GOV_SUSPEND 525 * event or when polling interval is set to zero. 526 * 527 * Note: Though this function is same as devfreq_monitor_stop(), 528 * intentionally kept separate to provide hooks for collecting 529 * transition statistics. 530 */ 531 void devfreq_monitor_suspend(struct devfreq *devfreq) 532 { 533 mutex_lock(&devfreq->lock); 534 if (devfreq->stop_polling) { 535 mutex_unlock(&devfreq->lock); 536 return; 537 } 538 539 devfreq_update_status(devfreq, devfreq->previous_freq); 540 devfreq->stop_polling = true; 541 mutex_unlock(&devfreq->lock); 542 543 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 544 return; 545 546 cancel_delayed_work_sync(&devfreq->work); 547 } 548 EXPORT_SYMBOL(devfreq_monitor_suspend); 549 550 /** 551 * devfreq_monitor_resume() - Resume load monitoring of a devfreq instance 552 * @devfreq: the devfreq instance. 553 * 554 * Helper function to resume devfreq device load monitoring. Function 555 * to be called from governor in response to DEVFREQ_GOV_RESUME 556 * event or when polling interval is set to non-zero. 557 */ 558 void devfreq_monitor_resume(struct devfreq *devfreq) 559 { 560 unsigned long freq; 561 562 mutex_lock(&devfreq->lock); 563 564 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 565 goto out_update; 566 567 if (!devfreq->stop_polling) 568 goto out; 569 570 if (!delayed_work_pending(&devfreq->work) && 571 devfreq->profile->polling_ms) 572 queue_delayed_work(devfreq_wq, &devfreq->work, 573 msecs_to_jiffies(devfreq->profile->polling_ms)); 574 575 out_update: 576 devfreq->stats.last_update = get_jiffies_64(); 577 devfreq->stop_polling = false; 578 579 if (devfreq->profile->get_cur_freq && 580 !devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq)) 581 devfreq->previous_freq = freq; 582 583 out: 584 mutex_unlock(&devfreq->lock); 585 } 586 EXPORT_SYMBOL(devfreq_monitor_resume); 587 588 /** 589 * devfreq_update_interval() - Update device devfreq monitoring interval 590 * @devfreq: the devfreq instance. 591 * @delay: new polling interval to be set. 592 * 593 * Helper function to set new load monitoring polling interval. Function 594 * to be called from governor in response to DEVFREQ_GOV_UPDATE_INTERVAL event. 595 */ 596 void devfreq_update_interval(struct devfreq *devfreq, unsigned int *delay) 597 { 598 unsigned int cur_delay = devfreq->profile->polling_ms; 599 unsigned int new_delay = *delay; 600 601 mutex_lock(&devfreq->lock); 602 devfreq->profile->polling_ms = new_delay; 603 604 if (IS_SUPPORTED_FLAG(devfreq->governor->flags, IRQ_DRIVEN)) 605 goto out; 606 607 if (devfreq->stop_polling) 608 goto out; 609 610 /* if new delay is zero, stop polling */ 611 if (!new_delay) { 612 mutex_unlock(&devfreq->lock); 613 cancel_delayed_work_sync(&devfreq->work); 614 return; 615 } 616 617 /* if current delay is zero, start polling with new delay */ 618 if (!cur_delay) { 619 queue_delayed_work(devfreq_wq, &devfreq->work, 620 msecs_to_jiffies(devfreq->profile->polling_ms)); 621 goto out; 622 } 623 624 /* if current delay is greater than new delay, restart polling */ 625 if (cur_delay > new_delay) { 626 mutex_unlock(&devfreq->lock); 627 cancel_delayed_work_sync(&devfreq->work); 628 mutex_lock(&devfreq->lock); 629 if (!devfreq->stop_polling) 630 queue_delayed_work(devfreq_wq, &devfreq->work, 631 msecs_to_jiffies(devfreq->profile->polling_ms)); 632 } 633 out: 634 mutex_unlock(&devfreq->lock); 635 } 636 EXPORT_SYMBOL(devfreq_update_interval); 637 638 /** 639 * devfreq_notifier_call() - Notify that the device frequency requirements 640 * has been changed out of devfreq framework. 641 * @nb: the notifier_block (supposed to be devfreq->nb) 642 * @type: not used 643 * @devp: not used 644 * 645 * Called by a notifier that uses devfreq->nb. 646 */ 647 static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, 648 void *devp) 649 { 650 struct devfreq *devfreq = container_of(nb, struct devfreq, nb); 651 int err = -EINVAL; 652 653 mutex_lock(&devfreq->lock); 654 655 devfreq->scaling_min_freq = find_available_min_freq(devfreq); 656 if (!devfreq->scaling_min_freq) 657 goto out; 658 659 devfreq->scaling_max_freq = find_available_max_freq(devfreq); 660 if (!devfreq->scaling_max_freq) { 661 devfreq->scaling_max_freq = ULONG_MAX; 662 goto out; 663 } 664 665 err = update_devfreq(devfreq); 666 667 out: 668 mutex_unlock(&devfreq->lock); 669 if (err) 670 dev_err(devfreq->dev.parent, 671 "failed to update frequency from OPP notifier (%d)\n", 672 err); 673 674 return NOTIFY_OK; 675 } 676 677 /** 678 * qos_notifier_call() - Common handler for QoS constraints. 679 * @devfreq: the devfreq instance. 680 */ 681 static int qos_notifier_call(struct devfreq *devfreq) 682 { 683 int err; 684 685 mutex_lock(&devfreq->lock); 686 err = update_devfreq(devfreq); 687 mutex_unlock(&devfreq->lock); 688 if (err) 689 dev_err(devfreq->dev.parent, 690 "failed to update frequency from PM QoS (%d)\n", 691 err); 692 693 return NOTIFY_OK; 694 } 695 696 /** 697 * qos_min_notifier_call() - Callback for QoS min_freq changes. 698 * @nb: Should be devfreq->nb_min 699 * @val: not used 700 * @ptr: not used 701 */ 702 static int qos_min_notifier_call(struct notifier_block *nb, 703 unsigned long val, void *ptr) 704 { 705 return qos_notifier_call(container_of(nb, struct devfreq, nb_min)); 706 } 707 708 /** 709 * qos_max_notifier_call() - Callback for QoS max_freq changes. 710 * @nb: Should be devfreq->nb_max 711 * @val: not used 712 * @ptr: not used 713 */ 714 static int qos_max_notifier_call(struct notifier_block *nb, 715 unsigned long val, void *ptr) 716 { 717 return qos_notifier_call(container_of(nb, struct devfreq, nb_max)); 718 } 719 720 /** 721 * devfreq_dev_release() - Callback for struct device to release the device. 722 * @dev: the devfreq device 723 * 724 * Remove devfreq from the list and release its resources. 725 */ 726 static void devfreq_dev_release(struct device *dev) 727 { 728 struct devfreq *devfreq = to_devfreq(dev); 729 int err; 730 731 mutex_lock(&devfreq_list_lock); 732 list_del(&devfreq->node); 733 mutex_unlock(&devfreq_list_lock); 734 735 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_max, 736 DEV_PM_QOS_MAX_FREQUENCY); 737 if (err && err != -ENOENT) 738 dev_warn(dev->parent, 739 "Failed to remove max_freq notifier: %d\n", err); 740 err = dev_pm_qos_remove_notifier(devfreq->dev.parent, &devfreq->nb_min, 741 DEV_PM_QOS_MIN_FREQUENCY); 742 if (err && err != -ENOENT) 743 dev_warn(dev->parent, 744 "Failed to remove min_freq notifier: %d\n", err); 745 746 if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { 747 err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); 748 if (err < 0) 749 dev_warn(dev->parent, 750 "Failed to remove max_freq request: %d\n", err); 751 } 752 if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { 753 err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); 754 if (err < 0) 755 dev_warn(dev->parent, 756 "Failed to remove min_freq request: %d\n", err); 757 } 758 759 if (devfreq->profile->exit) 760 devfreq->profile->exit(devfreq->dev.parent); 761 762 if (devfreq->opp_table) 763 dev_pm_opp_put_opp_table(devfreq->opp_table); 764 765 mutex_destroy(&devfreq->lock); 766 kfree(devfreq); 767 } 768 769 static void create_sysfs_files(struct devfreq *devfreq, 770 const struct devfreq_governor *gov); 771 static void remove_sysfs_files(struct devfreq *devfreq, 772 const struct devfreq_governor *gov); 773 774 /** 775 * devfreq_add_device() - Add devfreq feature to the device 776 * @dev: the device to add devfreq feature. 777 * @profile: device-specific profile to run devfreq. 778 * @governor_name: name of the policy to choose frequency. 779 * @data: devfreq driver pass to governors, governor should not change it. 780 */ 781 struct devfreq *devfreq_add_device(struct device *dev, 782 struct devfreq_dev_profile *profile, 783 const char *governor_name, 784 void *data) 785 { 786 struct devfreq *devfreq; 787 struct devfreq_governor *governor; 788 unsigned long min_freq, max_freq; 789 int err = 0; 790 791 if (!dev || !profile || !governor_name) { 792 dev_err(dev, "%s: Invalid parameters.\n", __func__); 793 return ERR_PTR(-EINVAL); 794 } 795 796 mutex_lock(&devfreq_list_lock); 797 devfreq = find_device_devfreq(dev); 798 mutex_unlock(&devfreq_list_lock); 799 if (!IS_ERR(devfreq)) { 800 dev_err(dev, "%s: devfreq device already exists!\n", 801 __func__); 802 err = -EINVAL; 803 goto err_out; 804 } 805 806 devfreq = kzalloc(sizeof(struct devfreq), GFP_KERNEL); 807 if (!devfreq) { 808 err = -ENOMEM; 809 goto err_out; 810 } 811 812 mutex_init(&devfreq->lock); 813 mutex_lock(&devfreq->lock); 814 devfreq->dev.parent = dev; 815 devfreq->dev.class = devfreq_class; 816 devfreq->dev.release = devfreq_dev_release; 817 INIT_LIST_HEAD(&devfreq->node); 818 devfreq->profile = profile; 819 devfreq->previous_freq = profile->initial_freq; 820 devfreq->last_status.current_frequency = profile->initial_freq; 821 devfreq->data = data; 822 devfreq->nb.notifier_call = devfreq_notifier_call; 823 824 if (devfreq->profile->timer < 0 825 || devfreq->profile->timer >= DEVFREQ_TIMER_NUM) { 826 mutex_unlock(&devfreq->lock); 827 err = -EINVAL; 828 goto err_dev; 829 } 830 831 if (!devfreq->profile->max_state || !devfreq->profile->freq_table) { 832 mutex_unlock(&devfreq->lock); 833 err = set_freq_table(devfreq); 834 if (err < 0) 835 goto err_dev; 836 mutex_lock(&devfreq->lock); 837 } else { 838 devfreq->freq_table = devfreq->profile->freq_table; 839 devfreq->max_state = devfreq->profile->max_state; 840 } 841 842 devfreq->scaling_min_freq = find_available_min_freq(devfreq); 843 if (!devfreq->scaling_min_freq) { 844 mutex_unlock(&devfreq->lock); 845 err = -EINVAL; 846 goto err_dev; 847 } 848 849 devfreq->scaling_max_freq = find_available_max_freq(devfreq); 850 if (!devfreq->scaling_max_freq) { 851 mutex_unlock(&devfreq->lock); 852 err = -EINVAL; 853 goto err_dev; 854 } 855 856 devfreq_get_freq_range(devfreq, &min_freq, &max_freq); 857 858 devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); 859 devfreq->opp_table = dev_pm_opp_get_opp_table(dev); 860 if (IS_ERR(devfreq->opp_table)) 861 devfreq->opp_table = NULL; 862 863 atomic_set(&devfreq->suspend_count, 0); 864 865 dev_set_name(&devfreq->dev, "%s", dev_name(dev)); 866 err = device_register(&devfreq->dev); 867 if (err) { 868 mutex_unlock(&devfreq->lock); 869 put_device(&devfreq->dev); 870 goto err_out; 871 } 872 873 devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev, 874 array3_size(sizeof(unsigned int), 875 devfreq->max_state, 876 devfreq->max_state), 877 GFP_KERNEL); 878 if (!devfreq->stats.trans_table) { 879 mutex_unlock(&devfreq->lock); 880 err = -ENOMEM; 881 goto err_devfreq; 882 } 883 884 devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev, 885 devfreq->max_state, 886 sizeof(*devfreq->stats.time_in_state), 887 GFP_KERNEL); 888 if (!devfreq->stats.time_in_state) { 889 mutex_unlock(&devfreq->lock); 890 err = -ENOMEM; 891 goto err_devfreq; 892 } 893 894 devfreq->stats.total_trans = 0; 895 devfreq->stats.last_update = get_jiffies_64(); 896 897 srcu_init_notifier_head(&devfreq->transition_notifier_list); 898 899 mutex_unlock(&devfreq->lock); 900 901 err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, 902 DEV_PM_QOS_MIN_FREQUENCY, 0); 903 if (err < 0) 904 goto err_devfreq; 905 err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, 906 DEV_PM_QOS_MAX_FREQUENCY, 907 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); 908 if (err < 0) 909 goto err_devfreq; 910 911 devfreq->nb_min.notifier_call = qos_min_notifier_call; 912 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_min, 913 DEV_PM_QOS_MIN_FREQUENCY); 914 if (err) 915 goto err_devfreq; 916 917 devfreq->nb_max.notifier_call = qos_max_notifier_call; 918 err = dev_pm_qos_add_notifier(dev, &devfreq->nb_max, 919 DEV_PM_QOS_MAX_FREQUENCY); 920 if (err) 921 goto err_devfreq; 922 923 mutex_lock(&devfreq_list_lock); 924 925 governor = try_then_request_governor(governor_name); 926 if (IS_ERR(governor)) { 927 dev_err(dev, "%s: Unable to find governor for the device\n", 928 __func__); 929 err = PTR_ERR(governor); 930 goto err_init; 931 } 932 933 devfreq->governor = governor; 934 err = devfreq->governor->event_handler(devfreq, DEVFREQ_GOV_START, 935 NULL); 936 if (err) { 937 dev_err_probe(dev, err, 938 "%s: Unable to start governor for the device\n", 939 __func__); 940 goto err_init; 941 } 942 create_sysfs_files(devfreq, devfreq->governor); 943 944 list_add(&devfreq->node, &devfreq_list); 945 946 mutex_unlock(&devfreq_list_lock); 947 948 if (devfreq->profile->is_cooling_device) { 949 devfreq->cdev = devfreq_cooling_em_register(devfreq, NULL); 950 if (IS_ERR(devfreq->cdev)) 951 devfreq->cdev = NULL; 952 } 953 954 return devfreq; 955 956 err_init: 957 mutex_unlock(&devfreq_list_lock); 958 err_devfreq: 959 devfreq_remove_device(devfreq); 960 devfreq = NULL; 961 err_dev: 962 kfree(devfreq); 963 err_out: 964 return ERR_PTR(err); 965 } 966 EXPORT_SYMBOL(devfreq_add_device); 967 968 /** 969 * devfreq_remove_device() - Remove devfreq feature from a device. 970 * @devfreq: the devfreq instance to be removed 971 * 972 * The opposite of devfreq_add_device(). 973 */ 974 int devfreq_remove_device(struct devfreq *devfreq) 975 { 976 if (!devfreq) 977 return -EINVAL; 978 979 devfreq_cooling_unregister(devfreq->cdev); 980 981 if (devfreq->governor) { 982 devfreq->governor->event_handler(devfreq, 983 DEVFREQ_GOV_STOP, NULL); 984 remove_sysfs_files(devfreq, devfreq->governor); 985 } 986 987 device_unregister(&devfreq->dev); 988 989 return 0; 990 } 991 EXPORT_SYMBOL(devfreq_remove_device); 992 993 static int devm_devfreq_dev_match(struct device *dev, void *res, void *data) 994 { 995 struct devfreq **r = res; 996 997 if (WARN_ON(!r || !*r)) 998 return 0; 999 1000 return *r == data; 1001 } 1002 1003 static void devm_devfreq_dev_release(struct device *dev, void *res) 1004 { 1005 devfreq_remove_device(*(struct devfreq **)res); 1006 } 1007 1008 /** 1009 * devm_devfreq_add_device() - Resource-managed devfreq_add_device() 1010 * @dev: the device to add devfreq feature. 1011 * @profile: device-specific profile to run devfreq. 1012 * @governor_name: name of the policy to choose frequency. 1013 * @data: devfreq driver pass to governors, governor should not change it. 1014 * 1015 * This function manages automatically the memory of devfreq device using device 1016 * resource management and simplify the free operation for memory of devfreq 1017 * device. 1018 */ 1019 struct devfreq *devm_devfreq_add_device(struct device *dev, 1020 struct devfreq_dev_profile *profile, 1021 const char *governor_name, 1022 void *data) 1023 { 1024 struct devfreq **ptr, *devfreq; 1025 1026 ptr = devres_alloc(devm_devfreq_dev_release, sizeof(*ptr), GFP_KERNEL); 1027 if (!ptr) 1028 return ERR_PTR(-ENOMEM); 1029 1030 devfreq = devfreq_add_device(dev, profile, governor_name, data); 1031 if (IS_ERR(devfreq)) { 1032 devres_free(ptr); 1033 return devfreq; 1034 } 1035 1036 *ptr = devfreq; 1037 devres_add(dev, ptr); 1038 1039 return devfreq; 1040 } 1041 EXPORT_SYMBOL(devm_devfreq_add_device); 1042 1043 #ifdef CONFIG_OF 1044 /* 1045 * devfreq_get_devfreq_by_node - Get the devfreq device from devicetree 1046 * @node - pointer to device_node 1047 * 1048 * return the instance of devfreq device 1049 */ 1050 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 1051 { 1052 struct devfreq *devfreq; 1053 1054 if (!node) 1055 return ERR_PTR(-EINVAL); 1056 1057 mutex_lock(&devfreq_list_lock); 1058 list_for_each_entry(devfreq, &devfreq_list, node) { 1059 if (devfreq->dev.parent 1060 && device_match_of_node(devfreq->dev.parent, node)) { 1061 mutex_unlock(&devfreq_list_lock); 1062 return devfreq; 1063 } 1064 } 1065 mutex_unlock(&devfreq_list_lock); 1066 1067 return ERR_PTR(-ENODEV); 1068 } 1069 1070 /* 1071 * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree 1072 * @dev - instance to the given device 1073 * @phandle_name - name of property holding a phandle value 1074 * @index - index into list of devfreq 1075 * 1076 * return the instance of devfreq device 1077 */ 1078 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 1079 const char *phandle_name, int index) 1080 { 1081 struct device_node *node; 1082 struct devfreq *devfreq; 1083 1084 if (!dev || !phandle_name) 1085 return ERR_PTR(-EINVAL); 1086 1087 if (!dev->of_node) 1088 return ERR_PTR(-EINVAL); 1089 1090 node = of_parse_phandle(dev->of_node, phandle_name, index); 1091 if (!node) 1092 return ERR_PTR(-ENODEV); 1093 1094 devfreq = devfreq_get_devfreq_by_node(node); 1095 of_node_put(node); 1096 1097 return devfreq; 1098 } 1099 1100 #else 1101 struct devfreq *devfreq_get_devfreq_by_node(struct device_node *node) 1102 { 1103 return ERR_PTR(-ENODEV); 1104 } 1105 1106 struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, 1107 const char *phandle_name, int index) 1108 { 1109 return ERR_PTR(-ENODEV); 1110 } 1111 #endif /* CONFIG_OF */ 1112 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_node); 1113 EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle); 1114 1115 /** 1116 * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device() 1117 * @dev: the device from which to remove devfreq feature. 1118 * @devfreq: the devfreq instance to be removed 1119 */ 1120 void devm_devfreq_remove_device(struct device *dev, struct devfreq *devfreq) 1121 { 1122 WARN_ON(devres_release(dev, devm_devfreq_dev_release, 1123 devm_devfreq_dev_match, devfreq)); 1124 } 1125 EXPORT_SYMBOL(devm_devfreq_remove_device); 1126 1127 /** 1128 * devfreq_suspend_device() - Suspend devfreq of a device. 1129 * @devfreq: the devfreq instance to be suspended 1130 * 1131 * This function is intended to be called by the pm callbacks 1132 * (e.g., runtime_suspend, suspend) of the device driver that 1133 * holds the devfreq. 1134 */ 1135 int devfreq_suspend_device(struct devfreq *devfreq) 1136 { 1137 int ret; 1138 1139 if (!devfreq) 1140 return -EINVAL; 1141 1142 if (atomic_inc_return(&devfreq->suspend_count) > 1) 1143 return 0; 1144 1145 if (devfreq->governor) { 1146 ret = devfreq->governor->event_handler(devfreq, 1147 DEVFREQ_GOV_SUSPEND, NULL); 1148 if (ret) 1149 return ret; 1150 } 1151 1152 if (devfreq->suspend_freq) { 1153 mutex_lock(&devfreq->lock); 1154 ret = devfreq_set_target(devfreq, devfreq->suspend_freq, 0); 1155 mutex_unlock(&devfreq->lock); 1156 if (ret) 1157 return ret; 1158 } 1159 1160 return 0; 1161 } 1162 EXPORT_SYMBOL(devfreq_suspend_device); 1163 1164 /** 1165 * devfreq_resume_device() - Resume devfreq of a device. 1166 * @devfreq: the devfreq instance to be resumed 1167 * 1168 * This function is intended to be called by the pm callbacks 1169 * (e.g., runtime_resume, resume) of the device driver that 1170 * holds the devfreq. 1171 */ 1172 int devfreq_resume_device(struct devfreq *devfreq) 1173 { 1174 int ret; 1175 1176 if (!devfreq) 1177 return -EINVAL; 1178 1179 if (atomic_dec_return(&devfreq->suspend_count) >= 1) 1180 return 0; 1181 1182 if (devfreq->resume_freq) { 1183 mutex_lock(&devfreq->lock); 1184 ret = devfreq_set_target(devfreq, devfreq->resume_freq, 0); 1185 mutex_unlock(&devfreq->lock); 1186 if (ret) 1187 return ret; 1188 } 1189 1190 if (devfreq->governor) { 1191 ret = devfreq->governor->event_handler(devfreq, 1192 DEVFREQ_GOV_RESUME, NULL); 1193 if (ret) 1194 return ret; 1195 } 1196 1197 return 0; 1198 } 1199 EXPORT_SYMBOL(devfreq_resume_device); 1200 1201 /** 1202 * devfreq_suspend() - Suspend devfreq governors and devices 1203 * 1204 * Called during system wide Suspend/Hibernate cycles for suspending governors 1205 * and devices preserving the state for resume. On some platforms the devfreq 1206 * device must have precise state (frequency) after resume in order to provide 1207 * fully operating setup. 1208 */ 1209 void devfreq_suspend(void) 1210 { 1211 struct devfreq *devfreq; 1212 int ret; 1213 1214 mutex_lock(&devfreq_list_lock); 1215 list_for_each_entry(devfreq, &devfreq_list, node) { 1216 ret = devfreq_suspend_device(devfreq); 1217 if (ret) 1218 dev_err(&devfreq->dev, 1219 "failed to suspend devfreq device\n"); 1220 } 1221 mutex_unlock(&devfreq_list_lock); 1222 } 1223 1224 /** 1225 * devfreq_resume() - Resume devfreq governors and devices 1226 * 1227 * Called during system wide Suspend/Hibernate cycle for resuming governors and 1228 * devices that are suspended with devfreq_suspend(). 1229 */ 1230 void devfreq_resume(void) 1231 { 1232 struct devfreq *devfreq; 1233 int ret; 1234 1235 mutex_lock(&devfreq_list_lock); 1236 list_for_each_entry(devfreq, &devfreq_list, node) { 1237 ret = devfreq_resume_device(devfreq); 1238 if (ret) 1239 dev_warn(&devfreq->dev, 1240 "failed to resume devfreq device\n"); 1241 } 1242 mutex_unlock(&devfreq_list_lock); 1243 } 1244 1245 /** 1246 * devfreq_add_governor() - Add devfreq governor 1247 * @governor: the devfreq governor to be added 1248 */ 1249 int devfreq_add_governor(struct devfreq_governor *governor) 1250 { 1251 struct devfreq_governor *g; 1252 struct devfreq *devfreq; 1253 int err = 0; 1254 1255 if (!governor) { 1256 pr_err("%s: Invalid parameters.\n", __func__); 1257 return -EINVAL; 1258 } 1259 1260 mutex_lock(&devfreq_list_lock); 1261 g = find_devfreq_governor(governor->name); 1262 if (!IS_ERR(g)) { 1263 pr_err("%s: governor %s already registered\n", __func__, 1264 g->name); 1265 err = -EINVAL; 1266 goto err_out; 1267 } 1268 1269 list_add(&governor->node, &devfreq_governor_list); 1270 1271 list_for_each_entry(devfreq, &devfreq_list, node) { 1272 int ret = 0; 1273 struct device *dev = devfreq->dev.parent; 1274 1275 if (!strncmp(devfreq->governor->name, governor->name, 1276 DEVFREQ_NAME_LEN)) { 1277 /* The following should never occur */ 1278 if (devfreq->governor) { 1279 dev_warn(dev, 1280 "%s: Governor %s already present\n", 1281 __func__, devfreq->governor->name); 1282 ret = devfreq->governor->event_handler(devfreq, 1283 DEVFREQ_GOV_STOP, NULL); 1284 if (ret) { 1285 dev_warn(dev, 1286 "%s: Governor %s stop = %d\n", 1287 __func__, 1288 devfreq->governor->name, ret); 1289 } 1290 /* Fall through */ 1291 } 1292 devfreq->governor = governor; 1293 ret = devfreq->governor->event_handler(devfreq, 1294 DEVFREQ_GOV_START, NULL); 1295 if (ret) { 1296 dev_warn(dev, "%s: Governor %s start=%d\n", 1297 __func__, devfreq->governor->name, 1298 ret); 1299 } 1300 } 1301 } 1302 1303 err_out: 1304 mutex_unlock(&devfreq_list_lock); 1305 1306 return err; 1307 } 1308 EXPORT_SYMBOL(devfreq_add_governor); 1309 1310 static void devm_devfreq_remove_governor(void *governor) 1311 { 1312 WARN_ON(devfreq_remove_governor(governor)); 1313 } 1314 1315 /** 1316 * devm_devfreq_add_governor() - Add devfreq governor 1317 * @dev: device which adds devfreq governor 1318 * @governor: the devfreq governor to be added 1319 * 1320 * This is a resource-managed variant of devfreq_add_governor(). 1321 */ 1322 int devm_devfreq_add_governor(struct device *dev, 1323 struct devfreq_governor *governor) 1324 { 1325 int err; 1326 1327 err = devfreq_add_governor(governor); 1328 if (err) 1329 return err; 1330 1331 return devm_add_action_or_reset(dev, devm_devfreq_remove_governor, 1332 governor); 1333 } 1334 EXPORT_SYMBOL(devm_devfreq_add_governor); 1335 1336 /** 1337 * devfreq_remove_governor() - Remove devfreq feature from a device. 1338 * @governor: the devfreq governor to be removed 1339 */ 1340 int devfreq_remove_governor(struct devfreq_governor *governor) 1341 { 1342 struct devfreq_governor *g; 1343 struct devfreq *devfreq; 1344 int err = 0; 1345 1346 if (!governor) { 1347 pr_err("%s: Invalid parameters.\n", __func__); 1348 return -EINVAL; 1349 } 1350 1351 mutex_lock(&devfreq_list_lock); 1352 g = find_devfreq_governor(governor->name); 1353 if (IS_ERR(g)) { 1354 pr_err("%s: governor %s not registered\n", __func__, 1355 governor->name); 1356 err = PTR_ERR(g); 1357 goto err_out; 1358 } 1359 list_for_each_entry(devfreq, &devfreq_list, node) { 1360 int ret; 1361 struct device *dev = devfreq->dev.parent; 1362 1363 if (!strncmp(devfreq->governor->name, governor->name, 1364 DEVFREQ_NAME_LEN)) { 1365 /* we should have a devfreq governor! */ 1366 if (!devfreq->governor) { 1367 dev_warn(dev, "%s: Governor %s NOT present\n", 1368 __func__, governor->name); 1369 continue; 1370 /* Fall through */ 1371 } 1372 ret = devfreq->governor->event_handler(devfreq, 1373 DEVFREQ_GOV_STOP, NULL); 1374 if (ret) { 1375 dev_warn(dev, "%s: Governor %s stop=%d\n", 1376 __func__, devfreq->governor->name, 1377 ret); 1378 } 1379 devfreq->governor = NULL; 1380 } 1381 } 1382 1383 list_del(&governor->node); 1384 err_out: 1385 mutex_unlock(&devfreq_list_lock); 1386 1387 return err; 1388 } 1389 EXPORT_SYMBOL(devfreq_remove_governor); 1390 1391 static ssize_t name_show(struct device *dev, 1392 struct device_attribute *attr, char *buf) 1393 { 1394 struct devfreq *df = to_devfreq(dev); 1395 return sprintf(buf, "%s\n", dev_name(df->dev.parent)); 1396 } 1397 static DEVICE_ATTR_RO(name); 1398 1399 static ssize_t governor_show(struct device *dev, 1400 struct device_attribute *attr, char *buf) 1401 { 1402 struct devfreq *df = to_devfreq(dev); 1403 1404 if (!df->governor) 1405 return -EINVAL; 1406 1407 return sprintf(buf, "%s\n", df->governor->name); 1408 } 1409 1410 static ssize_t governor_store(struct device *dev, struct device_attribute *attr, 1411 const char *buf, size_t count) 1412 { 1413 struct devfreq *df = to_devfreq(dev); 1414 int ret; 1415 char str_governor[DEVFREQ_NAME_LEN + 1]; 1416 const struct devfreq_governor *governor, *prev_governor; 1417 1418 if (!df->governor) 1419 return -EINVAL; 1420 1421 ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); 1422 if (ret != 1) 1423 return -EINVAL; 1424 1425 mutex_lock(&devfreq_list_lock); 1426 governor = try_then_request_governor(str_governor); 1427 if (IS_ERR(governor)) { 1428 ret = PTR_ERR(governor); 1429 goto out; 1430 } 1431 if (df->governor == governor) { 1432 ret = 0; 1433 goto out; 1434 } else if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE) 1435 || IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) { 1436 ret = -EINVAL; 1437 goto out; 1438 } 1439 1440 /* 1441 * Stop the current governor and remove the specific sysfs files 1442 * which depend on current governor. 1443 */ 1444 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); 1445 if (ret) { 1446 dev_warn(dev, "%s: Governor %s not stopped(%d)\n", 1447 __func__, df->governor->name, ret); 1448 goto out; 1449 } 1450 remove_sysfs_files(df, df->governor); 1451 1452 /* 1453 * Start the new governor and create the specific sysfs files 1454 * which depend on the new governor. 1455 */ 1456 prev_governor = df->governor; 1457 df->governor = governor; 1458 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1459 if (ret) { 1460 dev_warn(dev, "%s: Governor %s not started(%d)\n", 1461 __func__, df->governor->name, ret); 1462 1463 /* Restore previous governor */ 1464 df->governor = prev_governor; 1465 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1466 if (ret) { 1467 dev_err(dev, 1468 "%s: reverting to Governor %s failed (%d)\n", 1469 __func__, prev_governor->name, ret); 1470 df->governor = NULL; 1471 goto out; 1472 } 1473 } 1474 1475 /* 1476 * Create the sysfs files for the new governor. But if failed to start 1477 * the new governor, restore the sysfs files of previous governor. 1478 */ 1479 create_sysfs_files(df, df->governor); 1480 1481 out: 1482 mutex_unlock(&devfreq_list_lock); 1483 1484 if (!ret) 1485 ret = count; 1486 return ret; 1487 } 1488 static DEVICE_ATTR_RW(governor); 1489 1490 static ssize_t available_governors_show(struct device *d, 1491 struct device_attribute *attr, 1492 char *buf) 1493 { 1494 struct devfreq *df = to_devfreq(d); 1495 ssize_t count = 0; 1496 1497 if (!df->governor) 1498 return -EINVAL; 1499 1500 mutex_lock(&devfreq_list_lock); 1501 1502 /* 1503 * The devfreq with immutable governor (e.g., passive) shows 1504 * only own governor. 1505 */ 1506 if (IS_SUPPORTED_FLAG(df->governor->flags, IMMUTABLE)) { 1507 count = scnprintf(&buf[count], DEVFREQ_NAME_LEN, 1508 "%s ", df->governor->name); 1509 /* 1510 * The devfreq device shows the registered governor except for 1511 * immutable governors such as passive governor . 1512 */ 1513 } else { 1514 struct devfreq_governor *governor; 1515 1516 list_for_each_entry(governor, &devfreq_governor_list, node) { 1517 if (IS_SUPPORTED_FLAG(governor->flags, IMMUTABLE)) 1518 continue; 1519 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), 1520 "%s ", governor->name); 1521 } 1522 } 1523 1524 mutex_unlock(&devfreq_list_lock); 1525 1526 /* Truncate the trailing space */ 1527 if (count) 1528 count--; 1529 1530 count += sprintf(&buf[count], "\n"); 1531 1532 return count; 1533 } 1534 static DEVICE_ATTR_RO(available_governors); 1535 1536 static ssize_t cur_freq_show(struct device *dev, struct device_attribute *attr, 1537 char *buf) 1538 { 1539 unsigned long freq; 1540 struct devfreq *df = to_devfreq(dev); 1541 1542 if (!df->profile) 1543 return -EINVAL; 1544 1545 if (df->profile->get_cur_freq && 1546 !df->profile->get_cur_freq(df->dev.parent, &freq)) 1547 return sprintf(buf, "%lu\n", freq); 1548 1549 return sprintf(buf, "%lu\n", df->previous_freq); 1550 } 1551 static DEVICE_ATTR_RO(cur_freq); 1552 1553 static ssize_t target_freq_show(struct device *dev, 1554 struct device_attribute *attr, char *buf) 1555 { 1556 struct devfreq *df = to_devfreq(dev); 1557 1558 return sprintf(buf, "%lu\n", df->previous_freq); 1559 } 1560 static DEVICE_ATTR_RO(target_freq); 1561 1562 static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, 1563 const char *buf, size_t count) 1564 { 1565 struct devfreq *df = to_devfreq(dev); 1566 unsigned long value; 1567 int ret; 1568 1569 /* 1570 * Protect against theoretical sysfs writes between 1571 * device_add and dev_pm_qos_add_request 1572 */ 1573 if (!dev_pm_qos_request_active(&df->user_min_freq_req)) 1574 return -EAGAIN; 1575 1576 ret = sscanf(buf, "%lu", &value); 1577 if (ret != 1) 1578 return -EINVAL; 1579 1580 /* Round down to kHz for PM QoS */ 1581 ret = dev_pm_qos_update_request(&df->user_min_freq_req, 1582 value / HZ_PER_KHZ); 1583 if (ret < 0) 1584 return ret; 1585 1586 return count; 1587 } 1588 1589 static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, 1590 char *buf) 1591 { 1592 struct devfreq *df = to_devfreq(dev); 1593 unsigned long min_freq, max_freq; 1594 1595 mutex_lock(&df->lock); 1596 devfreq_get_freq_range(df, &min_freq, &max_freq); 1597 mutex_unlock(&df->lock); 1598 1599 return sprintf(buf, "%lu\n", min_freq); 1600 } 1601 static DEVICE_ATTR_RW(min_freq); 1602 1603 static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, 1604 const char *buf, size_t count) 1605 { 1606 struct devfreq *df = to_devfreq(dev); 1607 unsigned long value; 1608 int ret; 1609 1610 /* 1611 * Protect against theoretical sysfs writes between 1612 * device_add and dev_pm_qos_add_request 1613 */ 1614 if (!dev_pm_qos_request_active(&df->user_max_freq_req)) 1615 return -EINVAL; 1616 1617 ret = sscanf(buf, "%lu", &value); 1618 if (ret != 1) 1619 return -EINVAL; 1620 1621 /* 1622 * PM QoS frequencies are in kHz so we need to convert. Convert by 1623 * rounding upwards so that the acceptable interval never shrinks. 1624 * 1625 * For example if the user writes "666666666" to sysfs this value will 1626 * be converted to 666667 kHz and back to 666667000 Hz before an OPP 1627 * lookup, this ensures that an OPP of 666666666Hz is still accepted. 1628 * 1629 * A value of zero means "no limit". 1630 */ 1631 if (value) 1632 value = DIV_ROUND_UP(value, HZ_PER_KHZ); 1633 else 1634 value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; 1635 1636 ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); 1637 if (ret < 0) 1638 return ret; 1639 1640 return count; 1641 } 1642 1643 static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, 1644 char *buf) 1645 { 1646 struct devfreq *df = to_devfreq(dev); 1647 unsigned long min_freq, max_freq; 1648 1649 mutex_lock(&df->lock); 1650 devfreq_get_freq_range(df, &min_freq, &max_freq); 1651 mutex_unlock(&df->lock); 1652 1653 return sprintf(buf, "%lu\n", max_freq); 1654 } 1655 static DEVICE_ATTR_RW(max_freq); 1656 1657 static ssize_t available_frequencies_show(struct device *d, 1658 struct device_attribute *attr, 1659 char *buf) 1660 { 1661 struct devfreq *df = to_devfreq(d); 1662 ssize_t count = 0; 1663 int i; 1664 1665 if (!df->profile) 1666 return -EINVAL; 1667 1668 mutex_lock(&df->lock); 1669 1670 for (i = 0; i < df->max_state; i++) 1671 count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), 1672 "%lu ", df->freq_table[i]); 1673 1674 mutex_unlock(&df->lock); 1675 /* Truncate the trailing space */ 1676 if (count) 1677 count--; 1678 1679 count += sprintf(&buf[count], "\n"); 1680 1681 return count; 1682 } 1683 static DEVICE_ATTR_RO(available_frequencies); 1684 1685 static ssize_t trans_stat_show(struct device *dev, 1686 struct device_attribute *attr, char *buf) 1687 { 1688 struct devfreq *df = to_devfreq(dev); 1689 ssize_t len; 1690 int i, j; 1691 unsigned int max_state; 1692 1693 if (!df->profile) 1694 return -EINVAL; 1695 max_state = df->max_state; 1696 1697 if (max_state == 0) 1698 return sprintf(buf, "Not Supported.\n"); 1699 1700 mutex_lock(&df->lock); 1701 if (!df->stop_polling && 1702 devfreq_update_status(df, df->previous_freq)) { 1703 mutex_unlock(&df->lock); 1704 return 0; 1705 } 1706 mutex_unlock(&df->lock); 1707 1708 len = sprintf(buf, " From : To\n"); 1709 len += sprintf(buf + len, " :"); 1710 for (i = 0; i < max_state; i++) 1711 len += sprintf(buf + len, "%10lu", 1712 df->freq_table[i]); 1713 1714 len += sprintf(buf + len, " time(ms)\n"); 1715 1716 for (i = 0; i < max_state; i++) { 1717 if (df->freq_table[i] == df->previous_freq) 1718 len += sprintf(buf + len, "*"); 1719 else 1720 len += sprintf(buf + len, " "); 1721 1722 len += sprintf(buf + len, "%10lu:", df->freq_table[i]); 1723 for (j = 0; j < max_state; j++) 1724 len += sprintf(buf + len, "%10u", 1725 df->stats.trans_table[(i * max_state) + j]); 1726 1727 len += sprintf(buf + len, "%10llu\n", (u64) 1728 jiffies64_to_msecs(df->stats.time_in_state[i])); 1729 } 1730 1731 len += sprintf(buf + len, "Total transition : %u\n", 1732 df->stats.total_trans); 1733 return len; 1734 } 1735 1736 static ssize_t trans_stat_store(struct device *dev, 1737 struct device_attribute *attr, 1738 const char *buf, size_t count) 1739 { 1740 struct devfreq *df = to_devfreq(dev); 1741 int err, value; 1742 1743 if (!df->profile) 1744 return -EINVAL; 1745 1746 if (df->max_state == 0) 1747 return count; 1748 1749 err = kstrtoint(buf, 10, &value); 1750 if (err || value != 0) 1751 return -EINVAL; 1752 1753 mutex_lock(&df->lock); 1754 memset(df->stats.time_in_state, 0, (df->max_state * 1755 sizeof(*df->stats.time_in_state))); 1756 memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int), 1757 df->max_state, 1758 df->max_state)); 1759 df->stats.total_trans = 0; 1760 df->stats.last_update = get_jiffies_64(); 1761 mutex_unlock(&df->lock); 1762 1763 return count; 1764 } 1765 static DEVICE_ATTR_RW(trans_stat); 1766 1767 static struct attribute *devfreq_attrs[] = { 1768 &dev_attr_name.attr, 1769 &dev_attr_governor.attr, 1770 &dev_attr_available_governors.attr, 1771 &dev_attr_cur_freq.attr, 1772 &dev_attr_available_frequencies.attr, 1773 &dev_attr_target_freq.attr, 1774 &dev_attr_min_freq.attr, 1775 &dev_attr_max_freq.attr, 1776 &dev_attr_trans_stat.attr, 1777 NULL, 1778 }; 1779 ATTRIBUTE_GROUPS(devfreq); 1780 1781 static ssize_t polling_interval_show(struct device *dev, 1782 struct device_attribute *attr, char *buf) 1783 { 1784 struct devfreq *df = to_devfreq(dev); 1785 1786 if (!df->profile) 1787 return -EINVAL; 1788 1789 return sprintf(buf, "%d\n", df->profile->polling_ms); 1790 } 1791 1792 static ssize_t polling_interval_store(struct device *dev, 1793 struct device_attribute *attr, 1794 const char *buf, size_t count) 1795 { 1796 struct devfreq *df = to_devfreq(dev); 1797 unsigned int value; 1798 int ret; 1799 1800 if (!df->governor) 1801 return -EINVAL; 1802 1803 ret = sscanf(buf, "%u", &value); 1804 if (ret != 1) 1805 return -EINVAL; 1806 1807 df->governor->event_handler(df, DEVFREQ_GOV_UPDATE_INTERVAL, &value); 1808 ret = count; 1809 1810 return ret; 1811 } 1812 static DEVICE_ATTR_RW(polling_interval); 1813 1814 static ssize_t timer_show(struct device *dev, 1815 struct device_attribute *attr, char *buf) 1816 { 1817 struct devfreq *df = to_devfreq(dev); 1818 1819 if (!df->profile) 1820 return -EINVAL; 1821 1822 return sprintf(buf, "%s\n", timer_name[df->profile->timer]); 1823 } 1824 1825 static ssize_t timer_store(struct device *dev, struct device_attribute *attr, 1826 const char *buf, size_t count) 1827 { 1828 struct devfreq *df = to_devfreq(dev); 1829 char str_timer[DEVFREQ_NAME_LEN + 1]; 1830 int timer = -1; 1831 int ret = 0, i; 1832 1833 if (!df->governor || !df->profile) 1834 return -EINVAL; 1835 1836 ret = sscanf(buf, "%16s", str_timer); 1837 if (ret != 1) 1838 return -EINVAL; 1839 1840 for (i = 0; i < DEVFREQ_TIMER_NUM; i++) { 1841 if (!strncmp(timer_name[i], str_timer, DEVFREQ_NAME_LEN)) { 1842 timer = i; 1843 break; 1844 } 1845 } 1846 1847 if (timer < 0) { 1848 ret = -EINVAL; 1849 goto out; 1850 } 1851 1852 if (df->profile->timer == timer) { 1853 ret = 0; 1854 goto out; 1855 } 1856 1857 mutex_lock(&df->lock); 1858 df->profile->timer = timer; 1859 mutex_unlock(&df->lock); 1860 1861 ret = df->governor->event_handler(df, DEVFREQ_GOV_STOP, NULL); 1862 if (ret) { 1863 dev_warn(dev, "%s: Governor %s not stopped(%d)\n", 1864 __func__, df->governor->name, ret); 1865 goto out; 1866 } 1867 1868 ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); 1869 if (ret) 1870 dev_warn(dev, "%s: Governor %s not started(%d)\n", 1871 __func__, df->governor->name, ret); 1872 out: 1873 return ret ? ret : count; 1874 } 1875 static DEVICE_ATTR_RW(timer); 1876 1877 #define CREATE_SYSFS_FILE(df, name) \ 1878 { \ 1879 int ret; \ 1880 ret = sysfs_create_file(&df->dev.kobj, &dev_attr_##name.attr); \ 1881 if (ret < 0) { \ 1882 dev_warn(&df->dev, \ 1883 "Unable to create attr(%s)\n", "##name"); \ 1884 } \ 1885 } \ 1886 1887 /* Create the specific sysfs files which depend on each governor. */ 1888 static void create_sysfs_files(struct devfreq *devfreq, 1889 const struct devfreq_governor *gov) 1890 { 1891 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL)) 1892 CREATE_SYSFS_FILE(devfreq, polling_interval); 1893 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER)) 1894 CREATE_SYSFS_FILE(devfreq, timer); 1895 } 1896 1897 /* Remove the specific sysfs files which depend on each governor. */ 1898 static void remove_sysfs_files(struct devfreq *devfreq, 1899 const struct devfreq_governor *gov) 1900 { 1901 if (IS_SUPPORTED_ATTR(gov->attrs, POLLING_INTERVAL)) 1902 sysfs_remove_file(&devfreq->dev.kobj, 1903 &dev_attr_polling_interval.attr); 1904 if (IS_SUPPORTED_ATTR(gov->attrs, TIMER)) 1905 sysfs_remove_file(&devfreq->dev.kobj, &dev_attr_timer.attr); 1906 } 1907 1908 /** 1909 * devfreq_summary_show() - Show the summary of the devfreq devices 1910 * @s: seq_file instance to show the summary of devfreq devices 1911 * @data: not used 1912 * 1913 * Show the summary of the devfreq devices via 'devfreq_summary' debugfs file. 1914 * It helps that user can know the detailed information of the devfreq devices. 1915 * 1916 * Return 0 always because it shows the information without any data change. 1917 */ 1918 static int devfreq_summary_show(struct seq_file *s, void *data) 1919 { 1920 struct devfreq *devfreq; 1921 struct devfreq *p_devfreq = NULL; 1922 unsigned long cur_freq, min_freq, max_freq; 1923 unsigned int polling_ms; 1924 unsigned int timer; 1925 1926 seq_printf(s, "%-30s %-30s %-15s %-10s %10s %12s %12s %12s\n", 1927 "dev", 1928 "parent_dev", 1929 "governor", 1930 "timer", 1931 "polling_ms", 1932 "cur_freq_Hz", 1933 "min_freq_Hz", 1934 "max_freq_Hz"); 1935 seq_printf(s, "%30s %30s %15s %10s %10s %12s %12s %12s\n", 1936 "------------------------------", 1937 "------------------------------", 1938 "---------------", 1939 "----------", 1940 "----------", 1941 "------------", 1942 "------------", 1943 "------------"); 1944 1945 mutex_lock(&devfreq_list_lock); 1946 1947 list_for_each_entry_reverse(devfreq, &devfreq_list, node) { 1948 #if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE) 1949 if (!strncmp(devfreq->governor->name, DEVFREQ_GOV_PASSIVE, 1950 DEVFREQ_NAME_LEN)) { 1951 struct devfreq_passive_data *data = devfreq->data; 1952 1953 if (data) 1954 p_devfreq = data->parent; 1955 } else { 1956 p_devfreq = NULL; 1957 } 1958 #endif 1959 1960 mutex_lock(&devfreq->lock); 1961 cur_freq = devfreq->previous_freq; 1962 devfreq_get_freq_range(devfreq, &min_freq, &max_freq); 1963 timer = devfreq->profile->timer; 1964 1965 if (IS_SUPPORTED_ATTR(devfreq->governor->attrs, POLLING_INTERVAL)) 1966 polling_ms = devfreq->profile->polling_ms; 1967 else 1968 polling_ms = 0; 1969 mutex_unlock(&devfreq->lock); 1970 1971 seq_printf(s, 1972 "%-30s %-30s %-15s %-10s %10d %12ld %12ld %12ld\n", 1973 dev_name(&devfreq->dev), 1974 p_devfreq ? dev_name(&p_devfreq->dev) : "null", 1975 devfreq->governor->name, 1976 polling_ms ? timer_name[timer] : "null", 1977 polling_ms, 1978 cur_freq, 1979 min_freq, 1980 max_freq); 1981 } 1982 1983 mutex_unlock(&devfreq_list_lock); 1984 1985 return 0; 1986 } 1987 DEFINE_SHOW_ATTRIBUTE(devfreq_summary); 1988 1989 static int __init devfreq_init(void) 1990 { 1991 devfreq_class = class_create("devfreq"); 1992 if (IS_ERR(devfreq_class)) { 1993 pr_err("%s: couldn't create class\n", __FILE__); 1994 return PTR_ERR(devfreq_class); 1995 } 1996 1997 devfreq_wq = create_freezable_workqueue("devfreq_wq"); 1998 if (!devfreq_wq) { 1999 class_destroy(devfreq_class); 2000 pr_err("%s: couldn't create workqueue\n", __FILE__); 2001 return -ENOMEM; 2002 } 2003 devfreq_class->dev_groups = devfreq_groups; 2004 2005 devfreq_debugfs = debugfs_create_dir("devfreq", NULL); 2006 debugfs_create_file("devfreq_summary", 0444, 2007 devfreq_debugfs, NULL, 2008 &devfreq_summary_fops); 2009 2010 return 0; 2011 } 2012 subsys_initcall(devfreq_init); 2013 2014 /* 2015 * The following are helper functions for devfreq user device drivers with 2016 * OPP framework. 2017 */ 2018 2019 /** 2020 * devfreq_recommended_opp() - Helper function to get proper OPP for the 2021 * freq value given to target callback. 2022 * @dev: The devfreq user device. (parent of devfreq) 2023 * @freq: The frequency given to target function 2024 * @flags: Flags handed from devfreq framework. 2025 * 2026 * The callers are required to call dev_pm_opp_put() for the returned OPP after 2027 * use. 2028 */ 2029 struct dev_pm_opp *devfreq_recommended_opp(struct device *dev, 2030 unsigned long *freq, 2031 u32 flags) 2032 { 2033 struct dev_pm_opp *opp; 2034 2035 if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) { 2036 /* The freq is an upper bound. opp should be lower */ 2037 opp = dev_pm_opp_find_freq_floor(dev, freq); 2038 2039 /* If not available, use the closest opp */ 2040 if (opp == ERR_PTR(-ERANGE)) 2041 opp = dev_pm_opp_find_freq_ceil(dev, freq); 2042 } else { 2043 /* The freq is an lower bound. opp should be higher */ 2044 opp = dev_pm_opp_find_freq_ceil(dev, freq); 2045 2046 /* If not available, use the closest opp */ 2047 if (opp == ERR_PTR(-ERANGE)) 2048 opp = dev_pm_opp_find_freq_floor(dev, freq); 2049 } 2050 2051 return opp; 2052 } 2053 EXPORT_SYMBOL(devfreq_recommended_opp); 2054 2055 /** 2056 * devfreq_register_opp_notifier() - Helper function to get devfreq notified 2057 * for any changes in the OPP availability 2058 * changes 2059 * @dev: The devfreq user device. (parent of devfreq) 2060 * @devfreq: The devfreq object. 2061 */ 2062 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq) 2063 { 2064 return dev_pm_opp_register_notifier(dev, &devfreq->nb); 2065 } 2066 EXPORT_SYMBOL(devfreq_register_opp_notifier); 2067 2068 /** 2069 * devfreq_unregister_opp_notifier() - Helper function to stop getting devfreq 2070 * notified for any changes in the OPP 2071 * availability changes anymore. 2072 * @dev: The devfreq user device. (parent of devfreq) 2073 * @devfreq: The devfreq object. 2074 * 2075 * At exit() callback of devfreq_dev_profile, this must be included if 2076 * devfreq_recommended_opp is used. 2077 */ 2078 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq) 2079 { 2080 return dev_pm_opp_unregister_notifier(dev, &devfreq->nb); 2081 } 2082 EXPORT_SYMBOL(devfreq_unregister_opp_notifier); 2083 2084 static void devm_devfreq_opp_release(struct device *dev, void *res) 2085 { 2086 devfreq_unregister_opp_notifier(dev, *(struct devfreq **)res); 2087 } 2088 2089 /** 2090 * devm_devfreq_register_opp_notifier() - Resource-managed 2091 * devfreq_register_opp_notifier() 2092 * @dev: The devfreq user device. (parent of devfreq) 2093 * @devfreq: The devfreq object. 2094 */ 2095 int devm_devfreq_register_opp_notifier(struct device *dev, 2096 struct devfreq *devfreq) 2097 { 2098 struct devfreq **ptr; 2099 int ret; 2100 2101 ptr = devres_alloc(devm_devfreq_opp_release, sizeof(*ptr), GFP_KERNEL); 2102 if (!ptr) 2103 return -ENOMEM; 2104 2105 ret = devfreq_register_opp_notifier(dev, devfreq); 2106 if (ret) { 2107 devres_free(ptr); 2108 return ret; 2109 } 2110 2111 *ptr = devfreq; 2112 devres_add(dev, ptr); 2113 2114 return 0; 2115 } 2116 EXPORT_SYMBOL(devm_devfreq_register_opp_notifier); 2117 2118 /** 2119 * devm_devfreq_unregister_opp_notifier() - Resource-managed 2120 * devfreq_unregister_opp_notifier() 2121 * @dev: The devfreq user device. (parent of devfreq) 2122 * @devfreq: The devfreq object. 2123 */ 2124 void devm_devfreq_unregister_opp_notifier(struct device *dev, 2125 struct devfreq *devfreq) 2126 { 2127 WARN_ON(devres_release(dev, devm_devfreq_opp_release, 2128 devm_devfreq_dev_match, devfreq)); 2129 } 2130 EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier); 2131 2132 /** 2133 * devfreq_register_notifier() - Register a driver with devfreq 2134 * @devfreq: The devfreq object. 2135 * @nb: The notifier block to register. 2136 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2137 */ 2138 int devfreq_register_notifier(struct devfreq *devfreq, 2139 struct notifier_block *nb, 2140 unsigned int list) 2141 { 2142 int ret = 0; 2143 2144 if (!devfreq) 2145 return -EINVAL; 2146 2147 switch (list) { 2148 case DEVFREQ_TRANSITION_NOTIFIER: 2149 ret = srcu_notifier_chain_register( 2150 &devfreq->transition_notifier_list, nb); 2151 break; 2152 default: 2153 ret = -EINVAL; 2154 } 2155 2156 return ret; 2157 } 2158 EXPORT_SYMBOL(devfreq_register_notifier); 2159 2160 /* 2161 * devfreq_unregister_notifier() - Unregister a driver with devfreq 2162 * @devfreq: The devfreq object. 2163 * @nb: The notifier block to be unregistered. 2164 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2165 */ 2166 int devfreq_unregister_notifier(struct devfreq *devfreq, 2167 struct notifier_block *nb, 2168 unsigned int list) 2169 { 2170 int ret = 0; 2171 2172 if (!devfreq) 2173 return -EINVAL; 2174 2175 switch (list) { 2176 case DEVFREQ_TRANSITION_NOTIFIER: 2177 ret = srcu_notifier_chain_unregister( 2178 &devfreq->transition_notifier_list, nb); 2179 break; 2180 default: 2181 ret = -EINVAL; 2182 } 2183 2184 return ret; 2185 } 2186 EXPORT_SYMBOL(devfreq_unregister_notifier); 2187 2188 struct devfreq_notifier_devres { 2189 struct devfreq *devfreq; 2190 struct notifier_block *nb; 2191 unsigned int list; 2192 }; 2193 2194 static void devm_devfreq_notifier_release(struct device *dev, void *res) 2195 { 2196 struct devfreq_notifier_devres *this = res; 2197 2198 devfreq_unregister_notifier(this->devfreq, this->nb, this->list); 2199 } 2200 2201 /** 2202 * devm_devfreq_register_notifier() 2203 * - Resource-managed devfreq_register_notifier() 2204 * @dev: The devfreq user device. (parent of devfreq) 2205 * @devfreq: The devfreq object. 2206 * @nb: The notifier block to be unregistered. 2207 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2208 */ 2209 int devm_devfreq_register_notifier(struct device *dev, 2210 struct devfreq *devfreq, 2211 struct notifier_block *nb, 2212 unsigned int list) 2213 { 2214 struct devfreq_notifier_devres *ptr; 2215 int ret; 2216 2217 ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr), 2218 GFP_KERNEL); 2219 if (!ptr) 2220 return -ENOMEM; 2221 2222 ret = devfreq_register_notifier(devfreq, nb, list); 2223 if (ret) { 2224 devres_free(ptr); 2225 return ret; 2226 } 2227 2228 ptr->devfreq = devfreq; 2229 ptr->nb = nb; 2230 ptr->list = list; 2231 devres_add(dev, ptr); 2232 2233 return 0; 2234 } 2235 EXPORT_SYMBOL(devm_devfreq_register_notifier); 2236 2237 /** 2238 * devm_devfreq_unregister_notifier() 2239 * - Resource-managed devfreq_unregister_notifier() 2240 * @dev: The devfreq user device. (parent of devfreq) 2241 * @devfreq: The devfreq object. 2242 * @nb: The notifier block to be unregistered. 2243 * @list: DEVFREQ_TRANSITION_NOTIFIER. 2244 */ 2245 void devm_devfreq_unregister_notifier(struct device *dev, 2246 struct devfreq *devfreq, 2247 struct notifier_block *nb, 2248 unsigned int list) 2249 { 2250 WARN_ON(devres_release(dev, devm_devfreq_notifier_release, 2251 devm_devfreq_dev_match, devfreq)); 2252 } 2253 EXPORT_SYMBOL(devm_devfreq_unregister_notifier); 2254