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02361418 ADK |
1 | /* |
2 | * linux/drivers/thermal/cpu_cooling.c | |
3 | * | |
4 | * Copyright (C) 2012 Samsung Electronics Co., Ltd(http://www.samsung.com) | |
5 | * Copyright (C) 2012 Amit Daniel <amit.kachhap@linaro.org> | |
6 | * | |
7 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; version 2 of the License. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along | |
18 | * with this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
20 | * | |
21 | * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
22 | */ | |
02361418 ADK |
23 | #include <linux/module.h> |
24 | #include <linux/thermal.h> | |
02361418 ADK |
25 | #include <linux/cpufreq.h> |
26 | #include <linux/err.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/cpu.h> | |
29 | #include <linux/cpu_cooling.h> | |
30 | ||
31 | /** | |
3b3c0748 | 32 | * struct cpufreq_cooling_device - data for cooling device with cpufreq |
02361418 ADK |
33 | * @id: unique integer value corresponding to each cpufreq_cooling_device |
34 | * registered. | |
3b3c0748 EV |
35 | * @cool_dev: thermal_cooling_device pointer to keep track of the |
36 | * registered cooling device. | |
02361418 ADK |
37 | * @cpufreq_state: integer value representing the current state of cpufreq |
38 | * cooling devices. | |
39 | * @cpufreq_val: integer value representing the absolute value of the clipped | |
40 | * frequency. | |
41 | * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device. | |
02361418 ADK |
42 | * |
43 | * This structure is required for keeping information of each | |
67d0b2a8 | 44 | * cpufreq_cooling_device registered. In order to prevent corruption of this a |
02361418 ADK |
45 | * mutex lock cooling_cpufreq_lock is used. |
46 | */ | |
47 | struct cpufreq_cooling_device { | |
48 | int id; | |
49 | struct thermal_cooling_device *cool_dev; | |
50 | unsigned int cpufreq_state; | |
51 | unsigned int cpufreq_val; | |
52 | struct cpumask allowed_cpus; | |
02361418 | 53 | }; |
02361418 | 54 | static DEFINE_IDR(cpufreq_idr); |
160b7d80 | 55 | static DEFINE_MUTEX(cooling_cpufreq_lock); |
02361418 | 56 | |
160b7d80 | 57 | static unsigned int cpufreq_dev_count; |
02361418 ADK |
58 | |
59 | /* notify_table passes value to the CPUFREQ_ADJUST callback function. */ | |
60 | #define NOTIFY_INVALID NULL | |
a0f846c2 | 61 | static struct cpufreq_cooling_device *notify_device; |
02361418 ADK |
62 | |
63 | /** | |
64 | * get_idr - function to get a unique id. | |
65 | * @idr: struct idr * handle used to create a id. | |
66 | * @id: int * value generated by this function. | |
79491e53 EV |
67 | * |
68 | * This function will populate @id with an unique | |
69 | * id, using the idr API. | |
70 | * | |
71 | * Return: 0 on success, an error code on failure. | |
02361418 ADK |
72 | */ |
73 | static int get_idr(struct idr *idr, int *id) | |
74 | { | |
6deb69fa | 75 | int ret; |
02361418 ADK |
76 | |
77 | mutex_lock(&cooling_cpufreq_lock); | |
6deb69fa | 78 | ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL); |
02361418 | 79 | mutex_unlock(&cooling_cpufreq_lock); |
6deb69fa TH |
80 | if (unlikely(ret < 0)) |
81 | return ret; | |
82 | *id = ret; | |
79491e53 | 83 | |
02361418 ADK |
84 | return 0; |
85 | } | |
86 | ||
87 | /** | |
88 | * release_idr - function to free the unique id. | |
89 | * @idr: struct idr * handle used for creating the id. | |
90 | * @id: int value representing the unique id. | |
91 | */ | |
92 | static void release_idr(struct idr *idr, int id) | |
93 | { | |
94 | mutex_lock(&cooling_cpufreq_lock); | |
95 | idr_remove(idr, id); | |
96 | mutex_unlock(&cooling_cpufreq_lock); | |
97 | } | |
98 | ||
99 | /* Below code defines functions to be used for cpufreq as cooling device */ | |
100 | ||
101 | /** | |
82b9ee40 | 102 | * is_cpufreq_valid - function to check frequency transitioning capability. |
02361418 | 103 | * @cpu: cpu for which check is needed. |
82b9ee40 EV |
104 | * |
105 | * This function will check the current state of the system if | |
106 | * it is capable of changing the frequency for a given @cpu. | |
107 | * | |
108 | * Return: 0 if the system is not currently capable of changing | |
109 | * the frequency of given cpu. !0 in case the frequency is changeable. | |
02361418 ADK |
110 | */ |
111 | static int is_cpufreq_valid(int cpu) | |
112 | { | |
113 | struct cpufreq_policy policy; | |
79491e53 | 114 | |
02361418 ADK |
115 | return !cpufreq_get_policy(&policy, cpu); |
116 | } | |
117 | ||
fc35b35c ZR |
118 | enum cpufreq_cooling_property { |
119 | GET_LEVEL, | |
120 | GET_FREQ, | |
121 | GET_MAXL, | |
122 | }; | |
123 | ||
2d6f28fe EV |
124 | /** |
125 | * get_property - fetch a property of interest for a give cpu. | |
126 | * @cpu: cpu for which the property is required | |
127 | * @input: query parameter | |
128 | * @output: query return | |
129 | * @property: type of query (frequency, level, max level) | |
130 | * | |
131 | * This is the common function to | |
fc35b35c ZR |
132 | * 1. get maximum cpu cooling states |
133 | * 2. translate frequency to cooling state | |
134 | * 3. translate cooling state to frequency | |
135 | * Note that the code may be not in good shape | |
136 | * but it is written in this way in order to: | |
137 | * a) reduce duplicate code as most of the code can be shared. | |
138 | * b) make sure the logic is consistent when translating between | |
139 | * cooling states and frequencies. | |
2d6f28fe EV |
140 | * |
141 | * Return: 0 on success, -EINVAL when invalid parameters are passed. | |
142 | */ | |
fc35b35c | 143 | static int get_property(unsigned int cpu, unsigned long input, |
d8892a01 EV |
144 | unsigned int *output, |
145 | enum cpufreq_cooling_property property) | |
02361418 | 146 | { |
fc35b35c | 147 | int i, j; |
4469b997 | 148 | unsigned long max_level = 0, level = 0; |
fc35b35c ZR |
149 | unsigned int freq = CPUFREQ_ENTRY_INVALID; |
150 | int descend = -1; | |
02361418 ADK |
151 | struct cpufreq_frequency_table *table = |
152 | cpufreq_frequency_get_table(cpu); | |
79d26401 | 153 | |
fc35b35c ZR |
154 | if (!output) |
155 | return -EINVAL; | |
156 | ||
02361418 | 157 | if (!table) |
fc35b35c | 158 | return -EINVAL; |
02361418 | 159 | |
fc35b35c ZR |
160 | for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { |
161 | /* ignore invalid entries */ | |
02361418 ADK |
162 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) |
163 | continue; | |
164 | ||
fc35b35c ZR |
165 | /* ignore duplicate entry */ |
166 | if (freq == table[i].frequency) | |
167 | continue; | |
168 | ||
169 | /* get the frequency order */ | |
24c7a381 | 170 | if (freq != CPUFREQ_ENTRY_INVALID && descend == -1) |
fc35b35c | 171 | descend = !!(freq > table[i].frequency); |
02361418 | 172 | |
fc35b35c ZR |
173 | freq = table[i].frequency; |
174 | max_level++; | |
02361418 | 175 | } |
1c9573a4 EV |
176 | /* max_level is an index, not a counter */ |
177 | max_level--; | |
02361418 | 178 | |
fc35b35c ZR |
179 | /* get max level */ |
180 | if (property == GET_MAXL) { | |
181 | *output = (unsigned int)max_level; | |
182 | return 0; | |
183 | } | |
02361418 | 184 | |
fc35b35c | 185 | if (property == GET_FREQ) |
1c9573a4 | 186 | level = descend ? input : (max_level - input); |
fc35b35c | 187 | |
fc35b35c ZR |
188 | for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { |
189 | /* ignore invalid entry */ | |
02361418 ADK |
190 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) |
191 | continue; | |
fc35b35c ZR |
192 | |
193 | /* ignore duplicate entry */ | |
194 | if (freq == table[i].frequency) | |
195 | continue; | |
196 | ||
197 | /* now we have a valid frequency entry */ | |
198 | freq = table[i].frequency; | |
199 | ||
200 | if (property == GET_LEVEL && (unsigned int)input == freq) { | |
201 | /* get level by frequency */ | |
1c9573a4 | 202 | *output = descend ? j : (max_level - j); |
fc35b35c ZR |
203 | return 0; |
204 | } | |
205 | if (property == GET_FREQ && level == j) { | |
206 | /* get frequency by level */ | |
207 | *output = freq; | |
208 | return 0; | |
209 | } | |
210 | j++; | |
02361418 | 211 | } |
79491e53 | 212 | |
fc35b35c ZR |
213 | return -EINVAL; |
214 | } | |
215 | ||
44952d33 EV |
216 | /** |
217 | * cpufreq_cooling_get_level - for a give cpu, return the cooling level. | |
218 | * @cpu: cpu for which the level is required | |
219 | * @freq: the frequency of interest | |
220 | * | |
221 | * This function will match the cooling level corresponding to the | |
222 | * requested @freq and return it. | |
223 | * | |
224 | * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID | |
225 | * otherwise. | |
226 | */ | |
57df8106 ZR |
227 | unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq) |
228 | { | |
229 | unsigned int val; | |
230 | ||
231 | if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL)) | |
232 | return THERMAL_CSTATE_INVALID; | |
79491e53 | 233 | |
57df8106 ZR |
234 | return (unsigned long)val; |
235 | } | |
243dbd9c | 236 | EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level); |
57df8106 | 237 | |
fc35b35c ZR |
238 | /** |
239 | * get_cpu_frequency - get the absolute value of frequency from level. | |
240 | * @cpu: cpu for which frequency is fetched. | |
41518c41 EV |
241 | * @level: cooling level |
242 | * | |
243 | * This function matches cooling level with frequency. Based on a cooling level | |
244 | * of frequency, equals cooling state of cpu cooling device, it will return | |
245 | * the corresponding frequency. | |
fc35b35c | 246 | * e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc |
41518c41 EV |
247 | * |
248 | * Return: 0 on error, the corresponding frequency otherwise. | |
fc35b35c ZR |
249 | */ |
250 | static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) | |
251 | { | |
252 | int ret = 0; | |
253 | unsigned int freq; | |
254 | ||
255 | ret = get_property(cpu, level, &freq, GET_FREQ); | |
256 | if (ret) | |
257 | return 0; | |
79491e53 | 258 | |
fc35b35c | 259 | return freq; |
02361418 ADK |
260 | } |
261 | ||
262 | /** | |
263 | * cpufreq_apply_cooling - function to apply frequency clipping. | |
264 | * @cpufreq_device: cpufreq_cooling_device pointer containing frequency | |
265 | * clipping data. | |
266 | * @cooling_state: value of the cooling state. | |
4b33deb5 EV |
267 | * |
268 | * Function used to make sure the cpufreq layer is aware of current thermal | |
269 | * limits. The limits are applied by updating the cpufreq policy. | |
270 | * | |
271 | * Return: 0 on success, an error code otherwise (-EINVAL in case wrong | |
272 | * cooling state). | |
02361418 ADK |
273 | */ |
274 | static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, | |
5fda7f68 | 275 | unsigned long cooling_state) |
02361418 ADK |
276 | { |
277 | unsigned int cpuid, clip_freq; | |
bde00663 LNM |
278 | struct cpumask *mask = &cpufreq_device->allowed_cpus; |
279 | unsigned int cpu = cpumask_any(mask); | |
02361418 ADK |
280 | |
281 | ||
282 | /* Check if the old cooling action is same as new cooling action */ | |
283 | if (cpufreq_device->cpufreq_state == cooling_state) | |
284 | return 0; | |
285 | ||
286 | clip_freq = get_cpu_frequency(cpu, cooling_state); | |
287 | if (!clip_freq) | |
288 | return -EINVAL; | |
289 | ||
290 | cpufreq_device->cpufreq_state = cooling_state; | |
291 | cpufreq_device->cpufreq_val = clip_freq; | |
292 | notify_device = cpufreq_device; | |
293 | ||
bde00663 | 294 | for_each_cpu(cpuid, mask) { |
02361418 ADK |
295 | if (is_cpufreq_valid(cpuid)) |
296 | cpufreq_update_policy(cpuid); | |
297 | } | |
298 | ||
299 | notify_device = NOTIFY_INVALID; | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | /** | |
305 | * cpufreq_thermal_notifier - notifier callback for cpufreq policy change. | |
306 | * @nb: struct notifier_block * with callback info. | |
307 | * @event: value showing cpufreq event for which this function invoked. | |
308 | * @data: callback-specific data | |
bab30554 EV |
309 | * |
310 | * Callback to highjack the notification on cpufreq policy transition. | |
311 | * Every time there is a change in policy, we will intercept and | |
312 | * update the cpufreq policy with thermal constraints. | |
313 | * | |
314 | * Return: 0 (success) | |
02361418 ADK |
315 | */ |
316 | static int cpufreq_thermal_notifier(struct notifier_block *nb, | |
5fda7f68 | 317 | unsigned long event, void *data) |
02361418 ADK |
318 | { |
319 | struct cpufreq_policy *policy = data; | |
320 | unsigned long max_freq = 0; | |
321 | ||
322 | if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID) | |
323 | return 0; | |
324 | ||
325 | if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus)) | |
326 | max_freq = notify_device->cpufreq_val; | |
044d5c26 LT |
327 | else |
328 | return 0; | |
02361418 | 329 | |
1b9e3526 | 330 | /* Never exceed user_policy.max */ |
02361418 ADK |
331 | if (max_freq > policy->user_policy.max) |
332 | max_freq = policy->user_policy.max; | |
333 | ||
334 | if (policy->max != max_freq) | |
335 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
336 | ||
337 | return 0; | |
338 | } | |
339 | ||
1b9e3526 | 340 | /* cpufreq cooling device callback functions are defined below */ |
02361418 ADK |
341 | |
342 | /** | |
343 | * cpufreq_get_max_state - callback function to get the max cooling state. | |
344 | * @cdev: thermal cooling device pointer. | |
345 | * @state: fill this variable with the max cooling state. | |
62c00421 EV |
346 | * |
347 | * Callback for the thermal cooling device to return the cpufreq | |
348 | * max cooling state. | |
349 | * | |
350 | * Return: 0 on success, an error code otherwise. | |
02361418 ADK |
351 | */ |
352 | static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, | |
353 | unsigned long *state) | |
354 | { | |
160b7d80 | 355 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
bde00663 | 356 | struct cpumask *mask = &cpufreq_device->allowed_cpus; |
02361418 | 357 | unsigned int cpu; |
4f89038f | 358 | unsigned int count = 0; |
fc35b35c | 359 | int ret; |
02361418 | 360 | |
bde00663 | 361 | cpu = cpumask_any(mask); |
02361418 | 362 | |
4f89038f | 363 | ret = get_property(cpu, 0, &count, GET_MAXL); |
9c51b05a | 364 | |
fc35b35c ZR |
365 | if (count > 0) |
366 | *state = count; | |
02361418 | 367 | |
fc35b35c | 368 | return ret; |
02361418 ADK |
369 | } |
370 | ||
371 | /** | |
372 | * cpufreq_get_cur_state - callback function to get the current cooling state. | |
373 | * @cdev: thermal cooling device pointer. | |
374 | * @state: fill this variable with the current cooling state. | |
3672552d EV |
375 | * |
376 | * Callback for the thermal cooling device to return the cpufreq | |
377 | * current cooling state. | |
378 | * | |
379 | * Return: 0 on success, an error code otherwise. | |
02361418 ADK |
380 | */ |
381 | static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, | |
382 | unsigned long *state) | |
383 | { | |
160b7d80 | 384 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
02361418 | 385 | |
160b7d80 | 386 | *state = cpufreq_device->cpufreq_state; |
79491e53 | 387 | |
160b7d80 | 388 | return 0; |
02361418 ADK |
389 | } |
390 | ||
391 | /** | |
392 | * cpufreq_set_cur_state - callback function to set the current cooling state. | |
393 | * @cdev: thermal cooling device pointer. | |
394 | * @state: set this variable to the current cooling state. | |
56e05fdb EV |
395 | * |
396 | * Callback for the thermal cooling device to change the cpufreq | |
397 | * current cooling state. | |
398 | * | |
399 | * Return: 0 on success, an error code otherwise. | |
02361418 ADK |
400 | */ |
401 | static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, | |
402 | unsigned long state) | |
403 | { | |
160b7d80 | 404 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
02361418 | 405 | |
160b7d80 | 406 | return cpufreq_apply_cooling(cpufreq_device, state); |
02361418 ADK |
407 | } |
408 | ||
409 | /* Bind cpufreq callbacks to thermal cooling device ops */ | |
410 | static struct thermal_cooling_device_ops const cpufreq_cooling_ops = { | |
411 | .get_max_state = cpufreq_get_max_state, | |
412 | .get_cur_state = cpufreq_get_cur_state, | |
413 | .set_cur_state = cpufreq_set_cur_state, | |
414 | }; | |
415 | ||
416 | /* Notifier for cpufreq policy change */ | |
417 | static struct notifier_block thermal_cpufreq_notifier_block = { | |
418 | .notifier_call = cpufreq_thermal_notifier, | |
419 | }; | |
420 | ||
421 | /** | |
422 | * cpufreq_cooling_register - function to create cpufreq cooling device. | |
423 | * @clip_cpus: cpumask of cpus where the frequency constraints will happen. | |
12cb08ba EV |
424 | * |
425 | * This interface function registers the cpufreq cooling device with the name | |
426 | * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq | |
427 | * cooling devices. | |
428 | * | |
429 | * Return: a valid struct thermal_cooling_device pointer on success, | |
430 | * on failure, it returns a corresponding ERR_PTR(). | |
02361418 | 431 | */ |
5fda7f68 EV |
432 | struct thermal_cooling_device * |
433 | cpufreq_cooling_register(const struct cpumask *clip_cpus) | |
02361418 ADK |
434 | { |
435 | struct thermal_cooling_device *cool_dev; | |
436 | struct cpufreq_cooling_device *cpufreq_dev = NULL; | |
160b7d80 | 437 | unsigned int min = 0, max = 0; |
02361418 | 438 | char dev_name[THERMAL_NAME_LENGTH]; |
a4b6fec9 | 439 | int ret = 0, i; |
02361418 ADK |
440 | struct cpufreq_policy policy; |
441 | ||
1b9e3526 | 442 | /* Verify that all the clip cpus have same freq_min, freq_max limit */ |
02361418 | 443 | for_each_cpu(i, clip_cpus) { |
1b9e3526 | 444 | /* continue if cpufreq policy not found and not return error */ |
02361418 ADK |
445 | if (!cpufreq_get_policy(&policy, i)) |
446 | continue; | |
447 | if (min == 0 && max == 0) { | |
448 | min = policy.cpuinfo.min_freq; | |
449 | max = policy.cpuinfo.max_freq; | |
450 | } else { | |
451 | if (min != policy.cpuinfo.min_freq || | |
5fda7f68 | 452 | max != policy.cpuinfo.max_freq) |
02361418 | 453 | return ERR_PTR(-EINVAL); |
6b6519df | 454 | } |
02361418 ADK |
455 | } |
456 | cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device), | |
5fda7f68 | 457 | GFP_KERNEL); |
02361418 ADK |
458 | if (!cpufreq_dev) |
459 | return ERR_PTR(-ENOMEM); | |
460 | ||
461 | cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus); | |
462 | ||
02361418 ADK |
463 | ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); |
464 | if (ret) { | |
465 | kfree(cpufreq_dev); | |
466 | return ERR_PTR(-EINVAL); | |
467 | } | |
468 | ||
99871a71 EV |
469 | snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d", |
470 | cpufreq_dev->id); | |
02361418 ADK |
471 | |
472 | cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev, | |
5fda7f68 | 473 | &cpufreq_cooling_ops); |
73b9bcd7 | 474 | if (IS_ERR(cool_dev)) { |
02361418 ADK |
475 | release_idr(&cpufreq_idr, cpufreq_dev->id); |
476 | kfree(cpufreq_dev); | |
73b9bcd7 | 477 | return cool_dev; |
02361418 | 478 | } |
02361418 ADK |
479 | cpufreq_dev->cool_dev = cool_dev; |
480 | cpufreq_dev->cpufreq_state = 0; | |
481 | mutex_lock(&cooling_cpufreq_lock); | |
02361418 ADK |
482 | |
483 | /* Register the notifier for first cpufreq cooling device */ | |
484 | if (cpufreq_dev_count == 0) | |
485 | cpufreq_register_notifier(&thermal_cpufreq_notifier_block, | |
5fda7f68 | 486 | CPUFREQ_POLICY_NOTIFIER); |
160b7d80 | 487 | cpufreq_dev_count++; |
02361418 ADK |
488 | |
489 | mutex_unlock(&cooling_cpufreq_lock); | |
79491e53 | 490 | |
02361418 ADK |
491 | return cool_dev; |
492 | } | |
243dbd9c | 493 | EXPORT_SYMBOL_GPL(cpufreq_cooling_register); |
02361418 ADK |
494 | |
495 | /** | |
496 | * cpufreq_cooling_unregister - function to remove cpufreq cooling device. | |
497 | * @cdev: thermal cooling device pointer. | |
135266b4 EV |
498 | * |
499 | * This interface function unregisters the "thermal-cpufreq-%x" cooling device. | |
02361418 ADK |
500 | */ |
501 | void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) | |
502 | { | |
50e66c7e | 503 | struct cpufreq_cooling_device *cpufreq_dev; |
02361418 | 504 | |
50e66c7e EV |
505 | if (!cdev) |
506 | return; | |
507 | ||
508 | cpufreq_dev = cdev->devdata; | |
02361418 | 509 | mutex_lock(&cooling_cpufreq_lock); |
160b7d80 | 510 | cpufreq_dev_count--; |
02361418 ADK |
511 | |
512 | /* Unregister the notifier for the last cpufreq cooling device */ | |
2d9bf71c | 513 | if (cpufreq_dev_count == 0) |
02361418 | 514 | cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, |
5fda7f68 | 515 | CPUFREQ_POLICY_NOTIFIER); |
02361418 | 516 | mutex_unlock(&cooling_cpufreq_lock); |
160b7d80 | 517 | |
02361418 ADK |
518 | thermal_cooling_device_unregister(cpufreq_dev->cool_dev); |
519 | release_idr(&cpufreq_idr, cpufreq_dev->id); | |
02361418 ADK |
520 | kfree(cpufreq_dev); |
521 | } | |
243dbd9c | 522 | EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister); |