1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/drivers/thermal/cpufreq_cooling.c 4 * 5 * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) 6 * 7 * Copyright (C) 2012-2018 Linaro Limited. 8 * 9 * Authors: Amit Daniel <amit.kachhap@linaro.org> 10 * Viresh Kumar <viresh.kumar@linaro.org> 11 * 12 */ 13 #include <linux/cpu.h> 14 #include <linux/cpufreq.h> 15 #include <linux/cpu_cooling.h> 16 #include <linux/device.h> 17 #include <linux/energy_model.h> 18 #include <linux/err.h> 19 #include <linux/export.h> 20 #include <linux/pm_opp.h> 21 #include <linux/pm_qos.h> 22 #include <linux/slab.h> 23 #include <linux/thermal.h> 24 25 #include <trace/events/thermal.h> 26 27 /* 28 * Cooling state <-> CPUFreq frequency 29 * 30 * Cooling states are translated to frequencies throughout this driver and this 31 * is the relation between them. 32 * 33 * Highest cooling state corresponds to lowest possible frequency. 34 * 35 * i.e. 36 * level 0 --> 1st Max Freq 37 * level 1 --> 2nd Max Freq 38 * ... 39 */ 40 41 /** 42 * struct time_in_idle - Idle time stats 43 * @time: previous reading of the absolute time that this cpu was idle 44 * @timestamp: wall time of the last invocation of get_cpu_idle_time_us() 45 */ 46 struct time_in_idle { 47 u64 time; 48 u64 timestamp; 49 }; 50 51 /** 52 * struct cpufreq_cooling_device - data for cooling device with cpufreq 53 * @last_load: load measured by the latest call to cpufreq_get_requested_power() 54 * @cpufreq_state: integer value representing the current state of cpufreq 55 * cooling devices. 56 * @max_level: maximum cooling level. One less than total number of valid 57 * cpufreq frequencies. 58 * @em: Reference on the Energy Model of the device 59 * @cdev: thermal_cooling_device pointer to keep track of the 60 * registered cooling device. 61 * @policy: cpufreq policy. 62 * @node: list_head to link all cpufreq_cooling_device together. 63 * @idle_time: idle time stats 64 * @qos_req: PM QoS contraint to apply 65 * 66 * This structure is required for keeping information of each registered 67 * cpufreq_cooling_device. 68 */ 69 struct cpufreq_cooling_device { 70 u32 last_load; 71 unsigned int cpufreq_state; 72 unsigned int max_level; 73 struct em_perf_domain *em; 74 struct cpufreq_policy *policy; 75 struct list_head node; 76 #ifndef CONFIG_SMP 77 struct time_in_idle *idle_time; 78 #endif 79 struct freq_qos_request qos_req; 80 }; 81 82 static DEFINE_MUTEX(cooling_list_lock); 83 static LIST_HEAD(cpufreq_cdev_list); 84 85 #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR 86 /** 87 * get_level: Find the level for a particular frequency 88 * @cpufreq_cdev: cpufreq_cdev for which the property is required 89 * @freq: Frequency 90 * 91 * Return: level corresponding to the frequency. 92 */ 93 static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_cdev, 94 unsigned int freq) 95 { 96 int i; 97 98 for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { 99 if (freq > cpufreq_cdev->em->table[i].frequency) 100 break; 101 } 102 103 return cpufreq_cdev->max_level - i - 1; 104 } 105 106 static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev, 107 u32 freq) 108 { 109 int i; 110 111 for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { 112 if (freq > cpufreq_cdev->em->table[i].frequency) 113 break; 114 } 115 116 return cpufreq_cdev->em->table[i + 1].power; 117 } 118 119 static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, 120 u32 power) 121 { 122 int i; 123 124 for (i = cpufreq_cdev->max_level; i >= 0; i--) { 125 if (power >= cpufreq_cdev->em->table[i].power) 126 break; 127 } 128 129 return cpufreq_cdev->em->table[i].frequency; 130 } 131 132 /** 133 * get_load() - get load for a cpu 134 * @cpufreq_cdev: struct cpufreq_cooling_device for the cpu 135 * @cpu: cpu number 136 * @cpu_idx: index of the cpu in time_in_idle array 137 * 138 * Return: The average load of cpu @cpu in percentage since this 139 * function was last called. 140 */ 141 #ifdef CONFIG_SMP 142 static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, 143 int cpu_idx) 144 { 145 unsigned long max = arch_scale_cpu_capacity(cpu); 146 unsigned long util; 147 148 util = sched_cpu_util(cpu, max); 149 return (util * 100) / max; 150 } 151 #else /* !CONFIG_SMP */ 152 static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, 153 int cpu_idx) 154 { 155 u32 load; 156 u64 now, now_idle, delta_time, delta_idle; 157 struct time_in_idle *idle_time = &cpufreq_cdev->idle_time[cpu_idx]; 158 159 now_idle = get_cpu_idle_time(cpu, &now, 0); 160 delta_idle = now_idle - idle_time->time; 161 delta_time = now - idle_time->timestamp; 162 163 if (delta_time <= delta_idle) 164 load = 0; 165 else 166 load = div64_u64(100 * (delta_time - delta_idle), delta_time); 167 168 idle_time->time = now_idle; 169 idle_time->timestamp = now; 170 171 return load; 172 } 173 #endif /* CONFIG_SMP */ 174 175 /** 176 * get_dynamic_power() - calculate the dynamic power 177 * @cpufreq_cdev: &cpufreq_cooling_device for this cdev 178 * @freq: current frequency 179 * 180 * Return: the dynamic power consumed by the cpus described by 181 * @cpufreq_cdev. 182 */ 183 static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_cdev, 184 unsigned long freq) 185 { 186 u32 raw_cpu_power; 187 188 raw_cpu_power = cpu_freq_to_power(cpufreq_cdev, freq); 189 return (raw_cpu_power * cpufreq_cdev->last_load) / 100; 190 } 191 192 /** 193 * cpufreq_get_requested_power() - get the current power 194 * @cdev: &thermal_cooling_device pointer 195 * @power: pointer in which to store the resulting power 196 * 197 * Calculate the current power consumption of the cpus in milliwatts 198 * and store it in @power. This function should actually calculate 199 * the requested power, but it's hard to get the frequency that 200 * cpufreq would have assigned if there were no thermal limits. 201 * Instead, we calculate the current power on the assumption that the 202 * immediate future will look like the immediate past. 203 * 204 * We use the current frequency and the average load since this 205 * function was last called. In reality, there could have been 206 * multiple opps since this function was last called and that affects 207 * the load calculation. While it's not perfectly accurate, this 208 * simplification is good enough and works. REVISIT this, as more 209 * complex code may be needed if experiments show that it's not 210 * accurate enough. 211 * 212 * Return: 0 on success, -E* if getting the static power failed. 213 */ 214 static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev, 215 u32 *power) 216 { 217 unsigned long freq; 218 int i = 0, cpu; 219 u32 total_load = 0; 220 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 221 struct cpufreq_policy *policy = cpufreq_cdev->policy; 222 u32 *load_cpu = NULL; 223 224 freq = cpufreq_quick_get(policy->cpu); 225 226 if (trace_thermal_power_cpu_get_power_enabled()) { 227 u32 ncpus = cpumask_weight(policy->related_cpus); 228 229 load_cpu = kcalloc(ncpus, sizeof(*load_cpu), GFP_KERNEL); 230 } 231 232 for_each_cpu(cpu, policy->related_cpus) { 233 u32 load; 234 235 if (cpu_online(cpu)) 236 load = get_load(cpufreq_cdev, cpu, i); 237 else 238 load = 0; 239 240 total_load += load; 241 if (load_cpu) 242 load_cpu[i] = load; 243 244 i++; 245 } 246 247 cpufreq_cdev->last_load = total_load; 248 249 *power = get_dynamic_power(cpufreq_cdev, freq); 250 251 if (load_cpu) { 252 trace_thermal_power_cpu_get_power(policy->related_cpus, freq, 253 load_cpu, i, *power); 254 255 kfree(load_cpu); 256 } 257 258 return 0; 259 } 260 261 /** 262 * cpufreq_state2power() - convert a cpu cdev state to power consumed 263 * @cdev: &thermal_cooling_device pointer 264 * @state: cooling device state to be converted 265 * @power: pointer in which to store the resulting power 266 * 267 * Convert cooling device state @state into power consumption in 268 * milliwatts assuming 100% load. Store the calculated power in 269 * @power. 270 * 271 * Return: 0 on success, -EINVAL if the cooling device state could not 272 * be converted into a frequency or other -E* if there was an error 273 * when calculating the static power. 274 */ 275 static int cpufreq_state2power(struct thermal_cooling_device *cdev, 276 unsigned long state, u32 *power) 277 { 278 unsigned int freq, num_cpus, idx; 279 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 280 281 /* Request state should be less than max_level */ 282 if (state > cpufreq_cdev->max_level) 283 return -EINVAL; 284 285 num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus); 286 287 idx = cpufreq_cdev->max_level - state; 288 freq = cpufreq_cdev->em->table[idx].frequency; 289 *power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus; 290 291 return 0; 292 } 293 294 /** 295 * cpufreq_power2state() - convert power to a cooling device state 296 * @cdev: &thermal_cooling_device pointer 297 * @power: power in milliwatts to be converted 298 * @state: pointer in which to store the resulting state 299 * 300 * Calculate a cooling device state for the cpus described by @cdev 301 * that would allow them to consume at most @power mW and store it in 302 * @state. Note that this calculation depends on external factors 303 * such as the cpu load or the current static power. Calling this 304 * function with the same power as input can yield different cooling 305 * device states depending on those external factors. 306 * 307 * Return: 0 on success, -ENODEV if no cpus are online or -EINVAL if 308 * the calculated frequency could not be converted to a valid state. 309 * The latter should not happen unless the frequencies available to 310 * cpufreq have changed since the initialization of the cpu cooling 311 * device. 312 */ 313 static int cpufreq_power2state(struct thermal_cooling_device *cdev, 314 u32 power, unsigned long *state) 315 { 316 unsigned int target_freq; 317 u32 last_load, normalised_power; 318 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 319 struct cpufreq_policy *policy = cpufreq_cdev->policy; 320 321 last_load = cpufreq_cdev->last_load ?: 1; 322 normalised_power = (power * 100) / last_load; 323 target_freq = cpu_power_to_freq(cpufreq_cdev, normalised_power); 324 325 *state = get_level(cpufreq_cdev, target_freq); 326 trace_thermal_power_cpu_limit(policy->related_cpus, target_freq, *state, 327 power); 328 return 0; 329 } 330 331 static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev, 332 struct em_perf_domain *em) { 333 struct cpufreq_policy *policy; 334 unsigned int nr_levels; 335 336 if (!em) 337 return false; 338 339 policy = cpufreq_cdev->policy; 340 if (!cpumask_equal(policy->related_cpus, em_span_cpus(em))) { 341 pr_err("The span of pd %*pbl is misaligned with cpufreq policy %*pbl\n", 342 cpumask_pr_args(em_span_cpus(em)), 343 cpumask_pr_args(policy->related_cpus)); 344 return false; 345 } 346 347 nr_levels = cpufreq_cdev->max_level + 1; 348 if (em_pd_nr_perf_states(em) != nr_levels) { 349 pr_err("The number of performance states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n", 350 cpumask_pr_args(em_span_cpus(em)), 351 em_pd_nr_perf_states(em), nr_levels); 352 return false; 353 } 354 355 return true; 356 } 357 #endif /* CONFIG_THERMAL_GOV_POWER_ALLOCATOR */ 358 359 #ifdef CONFIG_SMP 360 static inline int allocate_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 361 { 362 return 0; 363 } 364 365 static inline void free_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 366 { 367 } 368 #else 369 static int allocate_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 370 { 371 unsigned int num_cpus = cpumask_weight(cpufreq_cdev->policy->related_cpus); 372 373 cpufreq_cdev->idle_time = kcalloc(num_cpus, 374 sizeof(*cpufreq_cdev->idle_time), 375 GFP_KERNEL); 376 if (!cpufreq_cdev->idle_time) 377 return -ENOMEM; 378 379 return 0; 380 } 381 382 static void free_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 383 { 384 kfree(cpufreq_cdev->idle_time); 385 cpufreq_cdev->idle_time = NULL; 386 } 387 #endif /* CONFIG_SMP */ 388 389 static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev, 390 unsigned long state) 391 { 392 struct cpufreq_policy *policy; 393 unsigned long idx; 394 395 #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR 396 /* Use the Energy Model table if available */ 397 if (cpufreq_cdev->em) { 398 idx = cpufreq_cdev->max_level - state; 399 return cpufreq_cdev->em->table[idx].frequency; 400 } 401 #endif 402 403 /* Otherwise, fallback on the CPUFreq table */ 404 policy = cpufreq_cdev->policy; 405 if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING) 406 idx = cpufreq_cdev->max_level - state; 407 else 408 idx = state; 409 410 return policy->freq_table[idx].frequency; 411 } 412 413 /* cpufreq cooling device callback functions are defined below */ 414 415 /** 416 * cpufreq_get_max_state - callback function to get the max cooling state. 417 * @cdev: thermal cooling device pointer. 418 * @state: fill this variable with the max cooling state. 419 * 420 * Callback for the thermal cooling device to return the cpufreq 421 * max cooling state. 422 * 423 * Return: 0 on success, an error code otherwise. 424 */ 425 static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, 426 unsigned long *state) 427 { 428 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 429 430 *state = cpufreq_cdev->max_level; 431 return 0; 432 } 433 434 /** 435 * cpufreq_get_cur_state - callback function to get the current cooling state. 436 * @cdev: thermal cooling device pointer. 437 * @state: fill this variable with the current cooling state. 438 * 439 * Callback for the thermal cooling device to return the cpufreq 440 * current cooling state. 441 * 442 * Return: 0 on success, an error code otherwise. 443 */ 444 static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, 445 unsigned long *state) 446 { 447 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 448 449 *state = cpufreq_cdev->cpufreq_state; 450 451 return 0; 452 } 453 454 /** 455 * cpufreq_set_cur_state - callback function to set the current cooling state. 456 * @cdev: thermal cooling device pointer. 457 * @state: set this variable to the current cooling state. 458 * 459 * Callback for the thermal cooling device to change the cpufreq 460 * current cooling state. 461 * 462 * Return: 0 on success, an error code otherwise. 463 */ 464 static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, 465 unsigned long state) 466 { 467 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 468 struct cpumask *cpus; 469 unsigned int frequency; 470 unsigned long max_capacity, capacity; 471 int ret; 472 473 /* Request state should be less than max_level */ 474 if (state > cpufreq_cdev->max_level) 475 return -EINVAL; 476 477 /* Check if the old cooling action is same as new cooling action */ 478 if (cpufreq_cdev->cpufreq_state == state) 479 return 0; 480 481 frequency = get_state_freq(cpufreq_cdev, state); 482 483 ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency); 484 if (ret >= 0) { 485 cpufreq_cdev->cpufreq_state = state; 486 cpus = cpufreq_cdev->policy->cpus; 487 max_capacity = arch_scale_cpu_capacity(cpumask_first(cpus)); 488 capacity = frequency * max_capacity; 489 capacity /= cpufreq_cdev->policy->cpuinfo.max_freq; 490 arch_set_thermal_pressure(cpus, max_capacity - capacity); 491 ret = 0; 492 } 493 494 return ret; 495 } 496 497 /* Bind cpufreq callbacks to thermal cooling device ops */ 498 499 static struct thermal_cooling_device_ops cpufreq_cooling_ops = { 500 .get_max_state = cpufreq_get_max_state, 501 .get_cur_state = cpufreq_get_cur_state, 502 .set_cur_state = cpufreq_set_cur_state, 503 }; 504 505 /** 506 * __cpufreq_cooling_register - helper function to create cpufreq cooling device 507 * @np: a valid struct device_node to the cooling device device tree node 508 * @policy: cpufreq policy 509 * Normally this should be same as cpufreq policy->related_cpus. 510 * @em: Energy Model of the cpufreq policy 511 * 512 * This interface function registers the cpufreq cooling device with the name 513 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq 514 * cooling devices. It also gives the opportunity to link the cooling device 515 * with a device tree node, in order to bind it via the thermal DT code. 516 * 517 * Return: a valid struct thermal_cooling_device pointer on success, 518 * on failure, it returns a corresponding ERR_PTR(). 519 */ 520 static struct thermal_cooling_device * 521 __cpufreq_cooling_register(struct device_node *np, 522 struct cpufreq_policy *policy, 523 struct em_perf_domain *em) 524 { 525 struct thermal_cooling_device *cdev; 526 struct cpufreq_cooling_device *cpufreq_cdev; 527 unsigned int i; 528 struct device *dev; 529 int ret; 530 struct thermal_cooling_device_ops *cooling_ops; 531 char *name; 532 533 dev = get_cpu_device(policy->cpu); 534 if (unlikely(!dev)) { 535 pr_warn("No cpu device for cpu %d\n", policy->cpu); 536 return ERR_PTR(-ENODEV); 537 } 538 539 if (IS_ERR_OR_NULL(policy)) { 540 pr_err("%s: cpufreq policy isn't valid: %p\n", __func__, policy); 541 return ERR_PTR(-EINVAL); 542 } 543 544 i = cpufreq_table_count_valid_entries(policy); 545 if (!i) { 546 pr_debug("%s: CPUFreq table not found or has no valid entries\n", 547 __func__); 548 return ERR_PTR(-ENODEV); 549 } 550 551 cpufreq_cdev = kzalloc(sizeof(*cpufreq_cdev), GFP_KERNEL); 552 if (!cpufreq_cdev) 553 return ERR_PTR(-ENOMEM); 554 555 cpufreq_cdev->policy = policy; 556 557 ret = allocate_idle_time(cpufreq_cdev); 558 if (ret) { 559 cdev = ERR_PTR(ret); 560 goto free_cdev; 561 } 562 563 /* max_level is an index, not a counter */ 564 cpufreq_cdev->max_level = i - 1; 565 566 cooling_ops = &cpufreq_cooling_ops; 567 568 #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR 569 if (em_is_sane(cpufreq_cdev, em)) { 570 cpufreq_cdev->em = em; 571 cooling_ops->get_requested_power = cpufreq_get_requested_power; 572 cooling_ops->state2power = cpufreq_state2power; 573 cooling_ops->power2state = cpufreq_power2state; 574 } else 575 #endif 576 if (policy->freq_table_sorted == CPUFREQ_TABLE_UNSORTED) { 577 pr_err("%s: unsorted frequency tables are not supported\n", 578 __func__); 579 cdev = ERR_PTR(-EINVAL); 580 goto free_idle_time; 581 } 582 583 ret = freq_qos_add_request(&policy->constraints, 584 &cpufreq_cdev->qos_req, FREQ_QOS_MAX, 585 get_state_freq(cpufreq_cdev, 0)); 586 if (ret < 0) { 587 pr_err("%s: Failed to add freq constraint (%d)\n", __func__, 588 ret); 589 cdev = ERR_PTR(ret); 590 goto free_idle_time; 591 } 592 593 cdev = ERR_PTR(-ENOMEM); 594 name = kasprintf(GFP_KERNEL, "cpufreq-%s", dev_name(dev)); 595 if (!name) 596 goto remove_qos_req; 597 598 cdev = thermal_of_cooling_device_register(np, name, cpufreq_cdev, 599 cooling_ops); 600 kfree(name); 601 602 if (IS_ERR(cdev)) 603 goto remove_qos_req; 604 605 mutex_lock(&cooling_list_lock); 606 list_add(&cpufreq_cdev->node, &cpufreq_cdev_list); 607 mutex_unlock(&cooling_list_lock); 608 609 return cdev; 610 611 remove_qos_req: 612 freq_qos_remove_request(&cpufreq_cdev->qos_req); 613 free_idle_time: 614 free_idle_time(cpufreq_cdev); 615 free_cdev: 616 kfree(cpufreq_cdev); 617 return cdev; 618 } 619 620 /** 621 * cpufreq_cooling_register - function to create cpufreq cooling device. 622 * @policy: cpufreq policy 623 * 624 * This interface function registers the cpufreq cooling device with the name 625 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq 626 * cooling devices. 627 * 628 * Return: a valid struct thermal_cooling_device pointer on success, 629 * on failure, it returns a corresponding ERR_PTR(). 630 */ 631 struct thermal_cooling_device * 632 cpufreq_cooling_register(struct cpufreq_policy *policy) 633 { 634 return __cpufreq_cooling_register(NULL, policy, NULL); 635 } 636 EXPORT_SYMBOL_GPL(cpufreq_cooling_register); 637 638 /** 639 * of_cpufreq_cooling_register - function to create cpufreq cooling device. 640 * @policy: cpufreq policy 641 * 642 * This interface function registers the cpufreq cooling device with the name 643 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq 644 * cooling devices. Using this API, the cpufreq cooling device will be 645 * linked to the device tree node provided. 646 * 647 * Using this function, the cooling device will implement the power 648 * extensions by using a simple cpu power model. The cpus must have 649 * registered their OPPs using the OPP library. 650 * 651 * It also takes into account, if property present in policy CPU node, the 652 * static power consumed by the cpu. 653 * 654 * Return: a valid struct thermal_cooling_device pointer on success, 655 * and NULL on failure. 656 */ 657 struct thermal_cooling_device * 658 of_cpufreq_cooling_register(struct cpufreq_policy *policy) 659 { 660 struct device_node *np = of_get_cpu_node(policy->cpu, NULL); 661 struct thermal_cooling_device *cdev = NULL; 662 663 if (!np) { 664 pr_err("cpufreq_cooling: OF node not available for cpu%d\n", 665 policy->cpu); 666 return NULL; 667 } 668 669 if (of_find_property(np, "#cooling-cells", NULL)) { 670 struct em_perf_domain *em = em_cpu_get(policy->cpu); 671 672 cdev = __cpufreq_cooling_register(np, policy, em); 673 if (IS_ERR(cdev)) { 674 pr_err("cpufreq_cooling: cpu%d failed to register as cooling device: %ld\n", 675 policy->cpu, PTR_ERR(cdev)); 676 cdev = NULL; 677 } 678 } 679 680 of_node_put(np); 681 return cdev; 682 } 683 EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register); 684 685 /** 686 * cpufreq_cooling_unregister - function to remove cpufreq cooling device. 687 * @cdev: thermal cooling device pointer. 688 * 689 * This interface function unregisters the "thermal-cpufreq-%x" cooling device. 690 */ 691 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) 692 { 693 struct cpufreq_cooling_device *cpufreq_cdev; 694 695 if (!cdev) 696 return; 697 698 cpufreq_cdev = cdev->devdata; 699 700 mutex_lock(&cooling_list_lock); 701 list_del(&cpufreq_cdev->node); 702 mutex_unlock(&cooling_list_lock); 703 704 thermal_cooling_device_unregister(cdev); 705 freq_qos_remove_request(&cpufreq_cdev->qos_req); 706 free_idle_time(cpufreq_cdev); 707 kfree(cpufreq_cdev); 708 } 709 EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister); 710