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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; | |
2dcd851f | 53 | struct list_head node; |
02361418 | 54 | }; |
02361418 | 55 | static DEFINE_IDR(cpufreq_idr); |
160b7d80 | 56 | static DEFINE_MUTEX(cooling_cpufreq_lock); |
02361418 | 57 | |
160b7d80 | 58 | static unsigned int cpufreq_dev_count; |
02361418 | 59 | |
2dcd851f | 60 | static LIST_HEAD(cpufreq_dev_list); |
02361418 ADK |
61 | |
62 | /** | |
63 | * get_idr - function to get a unique id. | |
64 | * @idr: struct idr * handle used to create a id. | |
65 | * @id: int * value generated by this function. | |
79491e53 EV |
66 | * |
67 | * This function will populate @id with an unique | |
68 | * id, using the idr API. | |
69 | * | |
70 | * Return: 0 on success, an error code on failure. | |
02361418 ADK |
71 | */ |
72 | static int get_idr(struct idr *idr, int *id) | |
73 | { | |
6deb69fa | 74 | int ret; |
02361418 ADK |
75 | |
76 | mutex_lock(&cooling_cpufreq_lock); | |
6deb69fa | 77 | ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL); |
02361418 | 78 | mutex_unlock(&cooling_cpufreq_lock); |
6deb69fa TH |
79 | if (unlikely(ret < 0)) |
80 | return ret; | |
81 | *id = ret; | |
79491e53 | 82 | |
02361418 ADK |
83 | return 0; |
84 | } | |
85 | ||
86 | /** | |
87 | * release_idr - function to free the unique id. | |
88 | * @idr: struct idr * handle used for creating the id. | |
89 | * @id: int value representing the unique id. | |
90 | */ | |
91 | static void release_idr(struct idr *idr, int id) | |
92 | { | |
93 | mutex_lock(&cooling_cpufreq_lock); | |
94 | idr_remove(idr, id); | |
95 | mutex_unlock(&cooling_cpufreq_lock); | |
96 | } | |
97 | ||
98 | /* Below code defines functions to be used for cpufreq as cooling device */ | |
99 | ||
100 | /** | |
82b9ee40 | 101 | * is_cpufreq_valid - function to check frequency transitioning capability. |
02361418 | 102 | * @cpu: cpu for which check is needed. |
82b9ee40 EV |
103 | * |
104 | * This function will check the current state of the system if | |
105 | * it is capable of changing the frequency for a given @cpu. | |
106 | * | |
107 | * Return: 0 if the system is not currently capable of changing | |
108 | * the frequency of given cpu. !0 in case the frequency is changeable. | |
02361418 ADK |
109 | */ |
110 | static int is_cpufreq_valid(int cpu) | |
111 | { | |
112 | struct cpufreq_policy policy; | |
79491e53 | 113 | |
02361418 ADK |
114 | return !cpufreq_get_policy(&policy, cpu); |
115 | } | |
116 | ||
fc35b35c ZR |
117 | enum cpufreq_cooling_property { |
118 | GET_LEVEL, | |
119 | GET_FREQ, | |
120 | GET_MAXL, | |
121 | }; | |
122 | ||
2d6f28fe EV |
123 | /** |
124 | * get_property - fetch a property of interest for a give cpu. | |
125 | * @cpu: cpu for which the property is required | |
126 | * @input: query parameter | |
127 | * @output: query return | |
128 | * @property: type of query (frequency, level, max level) | |
129 | * | |
130 | * This is the common function to | |
fc35b35c ZR |
131 | * 1. get maximum cpu cooling states |
132 | * 2. translate frequency to cooling state | |
133 | * 3. translate cooling state to frequency | |
134 | * Note that the code may be not in good shape | |
135 | * but it is written in this way in order to: | |
136 | * a) reduce duplicate code as most of the code can be shared. | |
137 | * b) make sure the logic is consistent when translating between | |
138 | * cooling states and frequencies. | |
2d6f28fe EV |
139 | * |
140 | * Return: 0 on success, -EINVAL when invalid parameters are passed. | |
141 | */ | |
fc35b35c | 142 | static int get_property(unsigned int cpu, unsigned long input, |
d8892a01 EV |
143 | unsigned int *output, |
144 | enum cpufreq_cooling_property property) | |
02361418 | 145 | { |
3c84ef3a | 146 | int i; |
4469b997 | 147 | unsigned long max_level = 0, level = 0; |
fc35b35c ZR |
148 | unsigned int freq = CPUFREQ_ENTRY_INVALID; |
149 | int descend = -1; | |
3c84ef3a | 150 | struct cpufreq_frequency_table *pos, *table = |
02361418 | 151 | cpufreq_frequency_get_table(cpu); |
79d26401 | 152 | |
fc35b35c ZR |
153 | if (!output) |
154 | return -EINVAL; | |
155 | ||
02361418 | 156 | if (!table) |
fc35b35c | 157 | return -EINVAL; |
02361418 | 158 | |
3c84ef3a | 159 | cpufreq_for_each_valid_entry(pos, table) { |
fc35b35c | 160 | /* ignore duplicate entry */ |
3c84ef3a | 161 | if (freq == pos->frequency) |
fc35b35c ZR |
162 | continue; |
163 | ||
164 | /* get the frequency order */ | |
24c7a381 | 165 | if (freq != CPUFREQ_ENTRY_INVALID && descend == -1) |
3c84ef3a | 166 | descend = freq > pos->frequency; |
02361418 | 167 | |
3c84ef3a | 168 | freq = pos->frequency; |
fc35b35c | 169 | max_level++; |
02361418 | 170 | } |
a116776f ZR |
171 | |
172 | /* No valid cpu frequency entry */ | |
173 | if (max_level == 0) | |
174 | return -EINVAL; | |
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 | |
3c84ef3a SK |
188 | i = 0; |
189 | cpufreq_for_each_valid_entry(pos, table) { | |
fc35b35c | 190 | /* ignore duplicate entry */ |
3c84ef3a | 191 | if (freq == pos->frequency) |
fc35b35c ZR |
192 | continue; |
193 | ||
194 | /* now we have a valid frequency entry */ | |
3c84ef3a | 195 | freq = pos->frequency; |
fc35b35c ZR |
196 | |
197 | if (property == GET_LEVEL && (unsigned int)input == freq) { | |
198 | /* get level by frequency */ | |
3c84ef3a | 199 | *output = descend ? i : (max_level - i); |
fc35b35c ZR |
200 | return 0; |
201 | } | |
3c84ef3a | 202 | if (property == GET_FREQ && level == i) { |
fc35b35c ZR |
203 | /* get frequency by level */ |
204 | *output = freq; | |
205 | return 0; | |
206 | } | |
3c84ef3a | 207 | i++; |
02361418 | 208 | } |
79491e53 | 209 | |
fc35b35c ZR |
210 | return -EINVAL; |
211 | } | |
212 | ||
44952d33 EV |
213 | /** |
214 | * cpufreq_cooling_get_level - for a give cpu, return the cooling level. | |
215 | * @cpu: cpu for which the level is required | |
216 | * @freq: the frequency of interest | |
217 | * | |
218 | * This function will match the cooling level corresponding to the | |
219 | * requested @freq and return it. | |
220 | * | |
221 | * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID | |
222 | * otherwise. | |
223 | */ | |
57df8106 ZR |
224 | unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq) |
225 | { | |
226 | unsigned int val; | |
227 | ||
228 | if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL)) | |
229 | return THERMAL_CSTATE_INVALID; | |
79491e53 | 230 | |
57df8106 ZR |
231 | return (unsigned long)val; |
232 | } | |
243dbd9c | 233 | EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level); |
57df8106 | 234 | |
fc35b35c ZR |
235 | /** |
236 | * get_cpu_frequency - get the absolute value of frequency from level. | |
237 | * @cpu: cpu for which frequency is fetched. | |
41518c41 EV |
238 | * @level: cooling level |
239 | * | |
240 | * This function matches cooling level with frequency. Based on a cooling level | |
241 | * of frequency, equals cooling state of cpu cooling device, it will return | |
242 | * the corresponding frequency. | |
fc35b35c | 243 | * e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc |
41518c41 EV |
244 | * |
245 | * Return: 0 on error, the corresponding frequency otherwise. | |
fc35b35c ZR |
246 | */ |
247 | static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) | |
248 | { | |
249 | int ret = 0; | |
250 | unsigned int freq; | |
251 | ||
252 | ret = get_property(cpu, level, &freq, GET_FREQ); | |
253 | if (ret) | |
254 | return 0; | |
79491e53 | 255 | |
fc35b35c | 256 | return freq; |
02361418 ADK |
257 | } |
258 | ||
259 | /** | |
260 | * cpufreq_apply_cooling - function to apply frequency clipping. | |
261 | * @cpufreq_device: cpufreq_cooling_device pointer containing frequency | |
262 | * clipping data. | |
263 | * @cooling_state: value of the cooling state. | |
4b33deb5 EV |
264 | * |
265 | * Function used to make sure the cpufreq layer is aware of current thermal | |
266 | * limits. The limits are applied by updating the cpufreq policy. | |
267 | * | |
268 | * Return: 0 on success, an error code otherwise (-EINVAL in case wrong | |
269 | * cooling state). | |
02361418 ADK |
270 | */ |
271 | static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, | |
5fda7f68 | 272 | unsigned long cooling_state) |
02361418 ADK |
273 | { |
274 | unsigned int cpuid, clip_freq; | |
bde00663 LNM |
275 | struct cpumask *mask = &cpufreq_device->allowed_cpus; |
276 | unsigned int cpu = cpumask_any(mask); | |
02361418 ADK |
277 | |
278 | ||
279 | /* Check if the old cooling action is same as new cooling action */ | |
280 | if (cpufreq_device->cpufreq_state == cooling_state) | |
281 | return 0; | |
282 | ||
283 | clip_freq = get_cpu_frequency(cpu, cooling_state); | |
284 | if (!clip_freq) | |
285 | return -EINVAL; | |
286 | ||
287 | cpufreq_device->cpufreq_state = cooling_state; | |
288 | cpufreq_device->cpufreq_val = clip_freq; | |
02361418 | 289 | |
bde00663 | 290 | for_each_cpu(cpuid, mask) { |
02361418 ADK |
291 | if (is_cpufreq_valid(cpuid)) |
292 | cpufreq_update_policy(cpuid); | |
293 | } | |
294 | ||
02361418 ADK |
295 | return 0; |
296 | } | |
297 | ||
298 | /** | |
299 | * cpufreq_thermal_notifier - notifier callback for cpufreq policy change. | |
300 | * @nb: struct notifier_block * with callback info. | |
301 | * @event: value showing cpufreq event for which this function invoked. | |
302 | * @data: callback-specific data | |
bab30554 | 303 | * |
9746b6e7 | 304 | * Callback to hijack the notification on cpufreq policy transition. |
bab30554 EV |
305 | * Every time there is a change in policy, we will intercept and |
306 | * update the cpufreq policy with thermal constraints. | |
307 | * | |
308 | * Return: 0 (success) | |
02361418 ADK |
309 | */ |
310 | static int cpufreq_thermal_notifier(struct notifier_block *nb, | |
5fda7f68 | 311 | unsigned long event, void *data) |
02361418 ADK |
312 | { |
313 | struct cpufreq_policy *policy = data; | |
314 | unsigned long max_freq = 0; | |
2dcd851f | 315 | struct cpufreq_cooling_device *cpufreq_dev; |
02361418 | 316 | |
2dcd851f | 317 | if (event != CPUFREQ_ADJUST) |
02361418 ADK |
318 | return 0; |
319 | ||
2dcd851f YSB |
320 | mutex_lock(&cooling_cpufreq_lock); |
321 | list_for_each_entry(cpufreq_dev, &cpufreq_dev_list, node) { | |
322 | if (!cpumask_test_cpu(policy->cpu, | |
323 | &cpufreq_dev->allowed_cpus)) | |
324 | continue; | |
325 | ||
326 | if (!cpufreq_dev->cpufreq_val) | |
327 | cpufreq_dev->cpufreq_val = get_cpu_frequency( | |
328 | cpumask_any(&cpufreq_dev->allowed_cpus), | |
329 | cpufreq_dev->cpufreq_state); | |
02361418 | 330 | |
2dcd851f | 331 | max_freq = cpufreq_dev->cpufreq_val; |
02361418 | 332 | |
2dcd851f YSB |
333 | if (policy->max != max_freq) |
334 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
335 | } | |
336 | mutex_unlock(&cooling_cpufreq_lock); | |
02361418 ADK |
337 | |
338 | return 0; | |
339 | } | |
340 | ||
1b9e3526 | 341 | /* cpufreq cooling device callback functions are defined below */ |
02361418 ADK |
342 | |
343 | /** | |
344 | * cpufreq_get_max_state - callback function to get the max cooling state. | |
345 | * @cdev: thermal cooling device pointer. | |
346 | * @state: fill this variable with the max cooling state. | |
62c00421 EV |
347 | * |
348 | * Callback for the thermal cooling device to return the cpufreq | |
349 | * max cooling state. | |
350 | * | |
351 | * Return: 0 on success, an error code otherwise. | |
02361418 ADK |
352 | */ |
353 | static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, | |
354 | unsigned long *state) | |
355 | { | |
160b7d80 | 356 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
bde00663 | 357 | struct cpumask *mask = &cpufreq_device->allowed_cpus; |
02361418 | 358 | unsigned int cpu; |
4f89038f | 359 | unsigned int count = 0; |
fc35b35c | 360 | int ret; |
02361418 | 361 | |
bde00663 | 362 | cpu = cpumask_any(mask); |
02361418 | 363 | |
4f89038f | 364 | ret = get_property(cpu, 0, &count, GET_MAXL); |
9c51b05a | 365 | |
fc35b35c ZR |
366 | if (count > 0) |
367 | *state = count; | |
02361418 | 368 | |
fc35b35c | 369 | return ret; |
02361418 ADK |
370 | } |
371 | ||
372 | /** | |
373 | * cpufreq_get_cur_state - callback function to get the current cooling state. | |
374 | * @cdev: thermal cooling device pointer. | |
375 | * @state: fill this variable with the current cooling state. | |
3672552d EV |
376 | * |
377 | * Callback for the thermal cooling device to return the cpufreq | |
378 | * current cooling state. | |
379 | * | |
380 | * Return: 0 on success, an error code otherwise. | |
02361418 ADK |
381 | */ |
382 | static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, | |
383 | unsigned long *state) | |
384 | { | |
160b7d80 | 385 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
02361418 | 386 | |
160b7d80 | 387 | *state = cpufreq_device->cpufreq_state; |
79491e53 | 388 | |
160b7d80 | 389 | return 0; |
02361418 ADK |
390 | } |
391 | ||
392 | /** | |
393 | * cpufreq_set_cur_state - callback function to set the current cooling state. | |
394 | * @cdev: thermal cooling device pointer. | |
395 | * @state: set this variable to the current cooling state. | |
56e05fdb EV |
396 | * |
397 | * Callback for the thermal cooling device to change the cpufreq | |
398 | * current cooling state. | |
399 | * | |
400 | * Return: 0 on success, an error code otherwise. | |
02361418 ADK |
401 | */ |
402 | static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, | |
403 | unsigned long state) | |
404 | { | |
160b7d80 | 405 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
02361418 | 406 | |
160b7d80 | 407 | return cpufreq_apply_cooling(cpufreq_device, state); |
02361418 ADK |
408 | } |
409 | ||
410 | /* Bind cpufreq callbacks to thermal cooling device ops */ | |
411 | static struct thermal_cooling_device_ops const cpufreq_cooling_ops = { | |
412 | .get_max_state = cpufreq_get_max_state, | |
413 | .get_cur_state = cpufreq_get_cur_state, | |
414 | .set_cur_state = cpufreq_set_cur_state, | |
415 | }; | |
416 | ||
417 | /* Notifier for cpufreq policy change */ | |
418 | static struct notifier_block thermal_cpufreq_notifier_block = { | |
419 | .notifier_call = cpufreq_thermal_notifier, | |
420 | }; | |
421 | ||
422 | /** | |
39d99cff EV |
423 | * __cpufreq_cooling_register - helper function to create cpufreq cooling device |
424 | * @np: a valid struct device_node to the cooling device device tree node | |
02361418 | 425 | * @clip_cpus: cpumask of cpus where the frequency constraints will happen. |
12cb08ba EV |
426 | * |
427 | * This interface function registers the cpufreq cooling device with the name | |
428 | * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq | |
39d99cff EV |
429 | * cooling devices. It also gives the opportunity to link the cooling device |
430 | * with a device tree node, in order to bind it via the thermal DT code. | |
12cb08ba EV |
431 | * |
432 | * Return: a valid struct thermal_cooling_device pointer on success, | |
433 | * on failure, it returns a corresponding ERR_PTR(). | |
02361418 | 434 | */ |
39d99cff EV |
435 | static struct thermal_cooling_device * |
436 | __cpufreq_cooling_register(struct device_node *np, | |
437 | const struct cpumask *clip_cpus) | |
02361418 ADK |
438 | { |
439 | struct thermal_cooling_device *cool_dev; | |
440 | struct cpufreq_cooling_device *cpufreq_dev = NULL; | |
160b7d80 | 441 | unsigned int min = 0, max = 0; |
02361418 | 442 | char dev_name[THERMAL_NAME_LENGTH]; |
a4b6fec9 | 443 | int ret = 0, i; |
02361418 ADK |
444 | struct cpufreq_policy policy; |
445 | ||
1b9e3526 | 446 | /* Verify that all the clip cpus have same freq_min, freq_max limit */ |
02361418 | 447 | for_each_cpu(i, clip_cpus) { |
1b9e3526 | 448 | /* continue if cpufreq policy not found and not return error */ |
02361418 ADK |
449 | if (!cpufreq_get_policy(&policy, i)) |
450 | continue; | |
451 | if (min == 0 && max == 0) { | |
452 | min = policy.cpuinfo.min_freq; | |
453 | max = policy.cpuinfo.max_freq; | |
454 | } else { | |
455 | if (min != policy.cpuinfo.min_freq || | |
5fda7f68 | 456 | max != policy.cpuinfo.max_freq) |
02361418 | 457 | return ERR_PTR(-EINVAL); |
6b6519df | 458 | } |
02361418 ADK |
459 | } |
460 | cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device), | |
5fda7f68 | 461 | GFP_KERNEL); |
02361418 ADK |
462 | if (!cpufreq_dev) |
463 | return ERR_PTR(-ENOMEM); | |
464 | ||
465 | cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus); | |
466 | ||
02361418 ADK |
467 | ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); |
468 | if (ret) { | |
469 | kfree(cpufreq_dev); | |
470 | return ERR_PTR(-EINVAL); | |
471 | } | |
472 | ||
99871a71 EV |
473 | snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d", |
474 | cpufreq_dev->id); | |
02361418 | 475 | |
39d99cff EV |
476 | cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev, |
477 | &cpufreq_cooling_ops); | |
73b9bcd7 | 478 | if (IS_ERR(cool_dev)) { |
02361418 ADK |
479 | release_idr(&cpufreq_idr, cpufreq_dev->id); |
480 | kfree(cpufreq_dev); | |
73b9bcd7 | 481 | return cool_dev; |
02361418 | 482 | } |
02361418 ADK |
483 | cpufreq_dev->cool_dev = cool_dev; |
484 | cpufreq_dev->cpufreq_state = 0; | |
485 | mutex_lock(&cooling_cpufreq_lock); | |
02361418 ADK |
486 | |
487 | /* Register the notifier for first cpufreq cooling device */ | |
488 | if (cpufreq_dev_count == 0) | |
489 | cpufreq_register_notifier(&thermal_cpufreq_notifier_block, | |
5fda7f68 | 490 | CPUFREQ_POLICY_NOTIFIER); |
160b7d80 | 491 | cpufreq_dev_count++; |
2dcd851f | 492 | list_add(&cpufreq_dev->node, &cpufreq_dev_list); |
02361418 ADK |
493 | |
494 | mutex_unlock(&cooling_cpufreq_lock); | |
79491e53 | 495 | |
02361418 ADK |
496 | return cool_dev; |
497 | } | |
39d99cff EV |
498 | |
499 | /** | |
500 | * cpufreq_cooling_register - function to create cpufreq cooling device. | |
501 | * @clip_cpus: cpumask of cpus where the frequency constraints will happen. | |
502 | * | |
503 | * This interface function registers the cpufreq cooling device with the name | |
504 | * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq | |
505 | * cooling devices. | |
506 | * | |
507 | * Return: a valid struct thermal_cooling_device pointer on success, | |
508 | * on failure, it returns a corresponding ERR_PTR(). | |
509 | */ | |
510 | struct thermal_cooling_device * | |
511 | cpufreq_cooling_register(const struct cpumask *clip_cpus) | |
512 | { | |
513 | return __cpufreq_cooling_register(NULL, clip_cpus); | |
514 | } | |
243dbd9c | 515 | EXPORT_SYMBOL_GPL(cpufreq_cooling_register); |
02361418 | 516 | |
39d99cff EV |
517 | /** |
518 | * of_cpufreq_cooling_register - function to create cpufreq cooling device. | |
519 | * @np: a valid struct device_node to the cooling device device tree node | |
520 | * @clip_cpus: cpumask of cpus where the frequency constraints will happen. | |
521 | * | |
522 | * This interface function registers the cpufreq cooling device with the name | |
523 | * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq | |
524 | * cooling devices. Using this API, the cpufreq cooling device will be | |
525 | * linked to the device tree node provided. | |
526 | * | |
527 | * Return: a valid struct thermal_cooling_device pointer on success, | |
528 | * on failure, it returns a corresponding ERR_PTR(). | |
529 | */ | |
530 | struct thermal_cooling_device * | |
531 | of_cpufreq_cooling_register(struct device_node *np, | |
532 | const struct cpumask *clip_cpus) | |
533 | { | |
534 | if (!np) | |
535 | return ERR_PTR(-EINVAL); | |
536 | ||
537 | return __cpufreq_cooling_register(np, clip_cpus); | |
538 | } | |
539 | EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register); | |
540 | ||
02361418 ADK |
541 | /** |
542 | * cpufreq_cooling_unregister - function to remove cpufreq cooling device. | |
543 | * @cdev: thermal cooling device pointer. | |
135266b4 EV |
544 | * |
545 | * This interface function unregisters the "thermal-cpufreq-%x" cooling device. | |
02361418 ADK |
546 | */ |
547 | void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) | |
548 | { | |
50e66c7e | 549 | struct cpufreq_cooling_device *cpufreq_dev; |
02361418 | 550 | |
50e66c7e EV |
551 | if (!cdev) |
552 | return; | |
553 | ||
554 | cpufreq_dev = cdev->devdata; | |
02361418 | 555 | mutex_lock(&cooling_cpufreq_lock); |
2dcd851f | 556 | list_del(&cpufreq_dev->node); |
160b7d80 | 557 | cpufreq_dev_count--; |
02361418 ADK |
558 | |
559 | /* Unregister the notifier for the last cpufreq cooling device */ | |
2d9bf71c | 560 | if (cpufreq_dev_count == 0) |
02361418 | 561 | cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, |
5fda7f68 | 562 | CPUFREQ_POLICY_NOTIFIER); |
02361418 | 563 | mutex_unlock(&cooling_cpufreq_lock); |
160b7d80 | 564 | |
02361418 ADK |
565 | thermal_cooling_device_unregister(cpufreq_dev->cool_dev); |
566 | release_idr(&cpufreq_idr, cpufreq_dev->id); | |
02361418 ADK |
567 | kfree(cpufreq_dev); |
568 | } | |
243dbd9c | 569 | EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister); |