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 #include <linux/units.h> 25 26 #include <trace/events/thermal.h> 27 28 /* 29 * Cooling state <-> CPUFreq frequency 30 * 31 * Cooling states are translated to frequencies throughout this driver and this 32 * is the relation between them. 33 * 34 * Highest cooling state corresponds to lowest possible frequency. 35 * 36 * i.e. 37 * level 0 --> 1st Max Freq 38 * level 1 --> 2nd Max Freq 39 * ... 40 */ 41 42 /** 43 * struct time_in_idle - Idle time stats 44 * @time: previous reading of the absolute time that this cpu was idle 45 * @timestamp: wall time of the last invocation of get_cpu_idle_time_us() 46 */ 47 struct time_in_idle { 48 u64 time; 49 u64 timestamp; 50 }; 51 52 /** 53 * struct cpufreq_cooling_device - data for cooling device with cpufreq 54 * @last_load: load measured by the latest call to cpufreq_get_requested_power() 55 * @cpufreq_state: integer value representing the current state of cpufreq 56 * cooling devices. 57 * @max_level: maximum cooling level. One less than total number of valid 58 * cpufreq frequencies. 59 * @em: Reference on the Energy Model of the device 60 * @cdev: thermal_cooling_device pointer to keep track of the 61 * registered cooling device. 62 * @policy: cpufreq policy. 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 #ifndef CONFIG_SMP 76 struct time_in_idle *idle_time; 77 #endif 78 struct freq_qos_request qos_req; 79 }; 80 81 #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR 82 /** 83 * get_level: Find the level for a particular frequency 84 * @cpufreq_cdev: cpufreq_cdev for which the property is required 85 * @freq: Frequency 86 * 87 * Return: level corresponding to the frequency. 88 */ 89 static unsigned long get_level(struct cpufreq_cooling_device *cpufreq_cdev, 90 unsigned int freq) 91 { 92 int i; 93 94 for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { 95 if (freq > cpufreq_cdev->em->table[i].frequency) 96 break; 97 } 98 99 return cpufreq_cdev->max_level - i - 1; 100 } 101 102 static u32 cpu_freq_to_power(struct cpufreq_cooling_device *cpufreq_cdev, 103 u32 freq) 104 { 105 unsigned long power_mw; 106 int i; 107 108 for (i = cpufreq_cdev->max_level - 1; i >= 0; i--) { 109 if (freq > cpufreq_cdev->em->table[i].frequency) 110 break; 111 } 112 113 power_mw = cpufreq_cdev->em->table[i + 1].power; 114 power_mw /= MICROWATT_PER_MILLIWATT; 115 116 return power_mw; 117 } 118 119 static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev, 120 u32 power) 121 { 122 unsigned long em_power_mw; 123 int i; 124 125 for (i = cpufreq_cdev->max_level; i > 0; i--) { 126 /* Convert EM power to milli-Watts to make safe comparison */ 127 em_power_mw = cpufreq_cdev->em->table[i].power; 128 em_power_mw /= MICROWATT_PER_MILLIWATT; 129 if (power >= em_power_mw) 130 break; 131 } 132 133 return cpufreq_cdev->em->table[i].frequency; 134 } 135 136 /** 137 * get_load() - get load for a cpu 138 * @cpufreq_cdev: struct cpufreq_cooling_device for the cpu 139 * @cpu: cpu number 140 * @cpu_idx: index of the cpu in time_in_idle array 141 * 142 * Return: The average load of cpu @cpu in percentage since this 143 * function was last called. 144 */ 145 #ifdef CONFIG_SMP 146 static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, 147 int cpu_idx) 148 { 149 unsigned long max = arch_scale_cpu_capacity(cpu); 150 unsigned long util; 151 152 util = sched_cpu_util(cpu, max); 153 return (util * 100) / max; 154 } 155 #else /* !CONFIG_SMP */ 156 static u32 get_load(struct cpufreq_cooling_device *cpufreq_cdev, int cpu, 157 int cpu_idx) 158 { 159 u32 load; 160 u64 now, now_idle, delta_time, delta_idle; 161 struct time_in_idle *idle_time = &cpufreq_cdev->idle_time[cpu_idx]; 162 163 now_idle = get_cpu_idle_time(cpu, &now, 0); 164 delta_idle = now_idle - idle_time->time; 165 delta_time = now - idle_time->timestamp; 166 167 if (delta_time <= delta_idle) 168 load = 0; 169 else 170 load = div64_u64(100 * (delta_time - delta_idle), delta_time); 171 172 idle_time->time = now_idle; 173 idle_time->timestamp = now; 174 175 return load; 176 } 177 #endif /* CONFIG_SMP */ 178 179 /** 180 * get_dynamic_power() - calculate the dynamic power 181 * @cpufreq_cdev: &cpufreq_cooling_device for this cdev 182 * @freq: current frequency 183 * 184 * Return: the dynamic power consumed by the cpus described by 185 * @cpufreq_cdev. 186 */ 187 static u32 get_dynamic_power(struct cpufreq_cooling_device *cpufreq_cdev, 188 unsigned long freq) 189 { 190 u32 raw_cpu_power; 191 192 raw_cpu_power = cpu_freq_to_power(cpufreq_cdev, freq); 193 return (raw_cpu_power * cpufreq_cdev->last_load) / 100; 194 } 195 196 /** 197 * cpufreq_get_requested_power() - get the current power 198 * @cdev: &thermal_cooling_device pointer 199 * @power: pointer in which to store the resulting power 200 * 201 * Calculate the current power consumption of the cpus in milliwatts 202 * and store it in @power. This function should actually calculate 203 * the requested power, but it's hard to get the frequency that 204 * cpufreq would have assigned if there were no thermal limits. 205 * Instead, we calculate the current power on the assumption that the 206 * immediate future will look like the immediate past. 207 * 208 * We use the current frequency and the average load since this 209 * function was last called. In reality, there could have been 210 * multiple opps since this function was last called and that affects 211 * the load calculation. While it's not perfectly accurate, this 212 * simplification is good enough and works. REVISIT this, as more 213 * complex code may be needed if experiments show that it's not 214 * accurate enough. 215 * 216 * Return: 0 on success, -E* if getting the static power failed. 217 */ 218 static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev, 219 u32 *power) 220 { 221 unsigned long freq; 222 int i = 0, cpu; 223 u32 total_load = 0; 224 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 225 struct cpufreq_policy *policy = cpufreq_cdev->policy; 226 u32 *load_cpu = NULL; 227 228 freq = cpufreq_quick_get(policy->cpu); 229 230 if (trace_thermal_power_cpu_get_power_enabled()) { 231 u32 ncpus = cpumask_weight(policy->related_cpus); 232 233 load_cpu = kcalloc(ncpus, sizeof(*load_cpu), GFP_KERNEL); 234 } 235 236 for_each_cpu(cpu, policy->related_cpus) { 237 u32 load; 238 239 if (cpu_online(cpu)) 240 load = get_load(cpufreq_cdev, cpu, i); 241 else 242 load = 0; 243 244 total_load += load; 245 if (load_cpu) 246 load_cpu[i] = load; 247 248 i++; 249 } 250 251 cpufreq_cdev->last_load = total_load; 252 253 *power = get_dynamic_power(cpufreq_cdev, freq); 254 255 if (load_cpu) { 256 trace_thermal_power_cpu_get_power(policy->related_cpus, freq, 257 load_cpu, i, *power); 258 259 kfree(load_cpu); 260 } 261 262 return 0; 263 } 264 265 /** 266 * cpufreq_state2power() - convert a cpu cdev state to power consumed 267 * @cdev: &thermal_cooling_device pointer 268 * @state: cooling device state to be converted 269 * @power: pointer in which to store the resulting power 270 * 271 * Convert cooling device state @state into power consumption in 272 * milliwatts assuming 100% load. Store the calculated power in 273 * @power. 274 * 275 * Return: 0 on success, -EINVAL if the cooling device state could not 276 * be converted into a frequency or other -E* if there was an error 277 * when calculating the static power. 278 */ 279 static int cpufreq_state2power(struct thermal_cooling_device *cdev, 280 unsigned long state, u32 *power) 281 { 282 unsigned int freq, num_cpus, idx; 283 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 284 285 /* Request state should be less than max_level */ 286 if (state > cpufreq_cdev->max_level) 287 return -EINVAL; 288 289 num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus); 290 291 idx = cpufreq_cdev->max_level - state; 292 freq = cpufreq_cdev->em->table[idx].frequency; 293 *power = cpu_freq_to_power(cpufreq_cdev, freq) * num_cpus; 294 295 return 0; 296 } 297 298 /** 299 * cpufreq_power2state() - convert power to a cooling device state 300 * @cdev: &thermal_cooling_device pointer 301 * @power: power in milliwatts to be converted 302 * @state: pointer in which to store the resulting state 303 * 304 * Calculate a cooling device state for the cpus described by @cdev 305 * that would allow them to consume at most @power mW and store it in 306 * @state. Note that this calculation depends on external factors 307 * such as the cpu load or the current static power. Calling this 308 * function with the same power as input can yield different cooling 309 * device states depending on those external factors. 310 * 311 * Return: 0 on success, -ENODEV if no cpus are online or -EINVAL if 312 * the calculated frequency could not be converted to a valid state. 313 * The latter should not happen unless the frequencies available to 314 * cpufreq have changed since the initialization of the cpu cooling 315 * device. 316 */ 317 static int cpufreq_power2state(struct thermal_cooling_device *cdev, 318 u32 power, unsigned long *state) 319 { 320 unsigned int target_freq; 321 u32 last_load, normalised_power; 322 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 323 struct cpufreq_policy *policy = cpufreq_cdev->policy; 324 325 last_load = cpufreq_cdev->last_load ?: 1; 326 normalised_power = (power * 100) / last_load; 327 target_freq = cpu_power_to_freq(cpufreq_cdev, normalised_power); 328 329 *state = get_level(cpufreq_cdev, target_freq); 330 trace_thermal_power_cpu_limit(policy->related_cpus, target_freq, *state, 331 power); 332 return 0; 333 } 334 335 static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev, 336 struct em_perf_domain *em) { 337 struct cpufreq_policy *policy; 338 unsigned int nr_levels; 339 340 if (!em || em_is_artificial(em)) 341 return false; 342 343 policy = cpufreq_cdev->policy; 344 if (!cpumask_equal(policy->related_cpus, em_span_cpus(em))) { 345 pr_err("The span of pd %*pbl is misaligned with cpufreq policy %*pbl\n", 346 cpumask_pr_args(em_span_cpus(em)), 347 cpumask_pr_args(policy->related_cpus)); 348 return false; 349 } 350 351 nr_levels = cpufreq_cdev->max_level + 1; 352 if (em_pd_nr_perf_states(em) != nr_levels) { 353 pr_err("The number of performance states in pd %*pbl (%u) doesn't match the number of cooling levels (%u)\n", 354 cpumask_pr_args(em_span_cpus(em)), 355 em_pd_nr_perf_states(em), nr_levels); 356 return false; 357 } 358 359 return true; 360 } 361 #endif /* CONFIG_THERMAL_GOV_POWER_ALLOCATOR */ 362 363 #ifdef CONFIG_SMP 364 static inline int allocate_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 365 { 366 return 0; 367 } 368 369 static inline void free_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 370 { 371 } 372 #else 373 static int allocate_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 374 { 375 unsigned int num_cpus = cpumask_weight(cpufreq_cdev->policy->related_cpus); 376 377 cpufreq_cdev->idle_time = kcalloc(num_cpus, 378 sizeof(*cpufreq_cdev->idle_time), 379 GFP_KERNEL); 380 if (!cpufreq_cdev->idle_time) 381 return -ENOMEM; 382 383 return 0; 384 } 385 386 static void free_idle_time(struct cpufreq_cooling_device *cpufreq_cdev) 387 { 388 kfree(cpufreq_cdev->idle_time); 389 cpufreq_cdev->idle_time = NULL; 390 } 391 #endif /* CONFIG_SMP */ 392 393 static unsigned int get_state_freq(struct cpufreq_cooling_device *cpufreq_cdev, 394 unsigned long state) 395 { 396 struct cpufreq_policy *policy; 397 unsigned long idx; 398 399 #ifdef CONFIG_THERMAL_GOV_POWER_ALLOCATOR 400 /* Use the Energy Model table if available */ 401 if (cpufreq_cdev->em) { 402 idx = cpufreq_cdev->max_level - state; 403 return cpufreq_cdev->em->table[idx].frequency; 404 } 405 #endif 406 407 /* Otherwise, fallback on the CPUFreq table */ 408 policy = cpufreq_cdev->policy; 409 if (policy->freq_table_sorted == CPUFREQ_TABLE_SORTED_ASCENDING) 410 idx = cpufreq_cdev->max_level - state; 411 else 412 idx = state; 413 414 return policy->freq_table[idx].frequency; 415 } 416 417 /* cpufreq cooling device callback functions are defined below */ 418 419 /** 420 * cpufreq_get_max_state - callback function to get the max cooling state. 421 * @cdev: thermal cooling device pointer. 422 * @state: fill this variable with the max cooling state. 423 * 424 * Callback for the thermal cooling device to return the cpufreq 425 * max cooling state. 426 * 427 * Return: 0 on success, an error code otherwise. 428 */ 429 static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, 430 unsigned long *state) 431 { 432 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 433 434 *state = cpufreq_cdev->max_level; 435 return 0; 436 } 437 438 /** 439 * cpufreq_get_cur_state - callback function to get the current cooling state. 440 * @cdev: thermal cooling device pointer. 441 * @state: fill this variable with the current cooling state. 442 * 443 * Callback for the thermal cooling device to return the cpufreq 444 * current cooling state. 445 * 446 * Return: 0 on success, an error code otherwise. 447 */ 448 static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, 449 unsigned long *state) 450 { 451 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 452 453 *state = cpufreq_cdev->cpufreq_state; 454 455 return 0; 456 } 457 458 /** 459 * cpufreq_set_cur_state - callback function to set the current cooling state. 460 * @cdev: thermal cooling device pointer. 461 * @state: set this variable to the current cooling state. 462 * 463 * Callback for the thermal cooling device to change the cpufreq 464 * current cooling state. 465 * 466 * Return: 0 on success, an error code otherwise. 467 */ 468 static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, 469 unsigned long state) 470 { 471 struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata; 472 struct cpumask *cpus; 473 unsigned int frequency; 474 int ret; 475 476 /* Request state should be less than max_level */ 477 if (state > cpufreq_cdev->max_level) 478 return -EINVAL; 479 480 /* Check if the old cooling action is same as new cooling action */ 481 if (cpufreq_cdev->cpufreq_state == state) 482 return 0; 483 484 frequency = get_state_freq(cpufreq_cdev, state); 485 486 ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency); 487 if (ret >= 0) { 488 cpufreq_cdev->cpufreq_state = state; 489 cpus = cpufreq_cdev->policy->related_cpus; 490 arch_update_thermal_pressure(cpus, frequency); 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 return cdev; 606 607 remove_qos_req: 608 freq_qos_remove_request(&cpufreq_cdev->qos_req); 609 free_idle_time: 610 free_idle_time(cpufreq_cdev); 611 free_cdev: 612 kfree(cpufreq_cdev); 613 return cdev; 614 } 615 616 /** 617 * cpufreq_cooling_register - function to create cpufreq cooling device. 618 * @policy: cpufreq policy 619 * 620 * This interface function registers the cpufreq cooling device with the name 621 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq 622 * cooling devices. 623 * 624 * Return: a valid struct thermal_cooling_device pointer on success, 625 * on failure, it returns a corresponding ERR_PTR(). 626 */ 627 struct thermal_cooling_device * 628 cpufreq_cooling_register(struct cpufreq_policy *policy) 629 { 630 return __cpufreq_cooling_register(NULL, policy, NULL); 631 } 632 EXPORT_SYMBOL_GPL(cpufreq_cooling_register); 633 634 /** 635 * of_cpufreq_cooling_register - function to create cpufreq cooling device. 636 * @policy: cpufreq policy 637 * 638 * This interface function registers the cpufreq cooling device with the name 639 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq 640 * cooling devices. Using this API, the cpufreq cooling device will be 641 * linked to the device tree node provided. 642 * 643 * Using this function, the cooling device will implement the power 644 * extensions by using a simple cpu power model. The cpus must have 645 * registered their OPPs using the OPP library. 646 * 647 * It also takes into account, if property present in policy CPU node, the 648 * static power consumed by the cpu. 649 * 650 * Return: a valid struct thermal_cooling_device pointer on success, 651 * and NULL on failure. 652 */ 653 struct thermal_cooling_device * 654 of_cpufreq_cooling_register(struct cpufreq_policy *policy) 655 { 656 struct device_node *np = of_get_cpu_node(policy->cpu, NULL); 657 struct thermal_cooling_device *cdev = NULL; 658 659 if (!np) { 660 pr_err("cpufreq_cooling: OF node not available for cpu%d\n", 661 policy->cpu); 662 return NULL; 663 } 664 665 if (of_find_property(np, "#cooling-cells", NULL)) { 666 struct em_perf_domain *em = em_cpu_get(policy->cpu); 667 668 cdev = __cpufreq_cooling_register(np, policy, em); 669 if (IS_ERR(cdev)) { 670 pr_err("cpufreq_cooling: cpu%d failed to register as cooling device: %ld\n", 671 policy->cpu, PTR_ERR(cdev)); 672 cdev = NULL; 673 } 674 } 675 676 of_node_put(np); 677 return cdev; 678 } 679 EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register); 680 681 /** 682 * cpufreq_cooling_unregister - function to remove cpufreq cooling device. 683 * @cdev: thermal cooling device pointer. 684 * 685 * This interface function unregisters the "thermal-cpufreq-%x" cooling device. 686 */ 687 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) 688 { 689 struct cpufreq_cooling_device *cpufreq_cdev; 690 691 if (!cdev) 692 return; 693 694 cpufreq_cdev = cdev->devdata; 695 696 thermal_cooling_device_unregister(cdev); 697 freq_qos_remove_request(&cpufreq_cdev->qos_req); 698 free_idle_time(cpufreq_cdev); 699 kfree(cpufreq_cdev); 700 } 701 EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister); 702