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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 | */ | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/thermal.h> | |
26 | #include <linux/platform_device.h> | |
27 | #include <linux/cpufreq.h> | |
28 | #include <linux/err.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/cpu.h> | |
31 | #include <linux/cpu_cooling.h> | |
32 | ||
33 | /** | |
34 | * struct cpufreq_cooling_device | |
35 | * @id: unique integer value corresponding to each cpufreq_cooling_device | |
36 | * registered. | |
37 | * @cool_dev: thermal_cooling_device pointer to keep track of the the | |
38 | * egistered cooling device. | |
39 | * @cpufreq_state: integer value representing the current state of cpufreq | |
40 | * cooling devices. | |
41 | * @cpufreq_val: integer value representing the absolute value of the clipped | |
42 | * frequency. | |
43 | * @allowed_cpus: all the cpus involved for this cpufreq_cooling_device. | |
44 | * @node: list_head to link all cpufreq_cooling_device together. | |
45 | * | |
46 | * This structure is required for keeping information of each | |
47 | * cpufreq_cooling_device registered as a list whose head is represented by | |
48 | * cooling_cpufreq_list. In order to prevent corruption of this list a | |
49 | * mutex lock cooling_cpufreq_lock is used. | |
50 | */ | |
51 | struct cpufreq_cooling_device { | |
52 | int id; | |
53 | struct thermal_cooling_device *cool_dev; | |
54 | unsigned int cpufreq_state; | |
55 | unsigned int cpufreq_val; | |
56 | struct cpumask allowed_cpus; | |
57 | struct list_head node; | |
58 | }; | |
59 | static LIST_HEAD(cooling_cpufreq_list); | |
60 | static DEFINE_IDR(cpufreq_idr); | |
61 | ||
62 | static struct mutex cooling_cpufreq_lock; | |
63 | ||
64 | /* notify_table passes value to the CPUFREQ_ADJUST callback function. */ | |
65 | #define NOTIFY_INVALID NULL | |
66 | struct cpufreq_cooling_device *notify_device; | |
67 | ||
68 | /** | |
69 | * get_idr - function to get a unique id. | |
70 | * @idr: struct idr * handle used to create a id. | |
71 | * @id: int * value generated by this function. | |
72 | */ | |
73 | static int get_idr(struct idr *idr, int *id) | |
74 | { | |
75 | int err; | |
76 | again: | |
77 | if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0)) | |
78 | return -ENOMEM; | |
79 | ||
80 | mutex_lock(&cooling_cpufreq_lock); | |
81 | err = idr_get_new(idr, NULL, id); | |
82 | mutex_unlock(&cooling_cpufreq_lock); | |
83 | ||
84 | if (unlikely(err == -EAGAIN)) | |
85 | goto again; | |
86 | else if (unlikely(err)) | |
87 | return err; | |
88 | ||
89 | *id = *id & MAX_ID_MASK; | |
90 | return 0; | |
91 | } | |
92 | ||
93 | /** | |
94 | * release_idr - function to free the unique id. | |
95 | * @idr: struct idr * handle used for creating the id. | |
96 | * @id: int value representing the unique id. | |
97 | */ | |
98 | static void release_idr(struct idr *idr, int id) | |
99 | { | |
100 | mutex_lock(&cooling_cpufreq_lock); | |
101 | idr_remove(idr, id); | |
102 | mutex_unlock(&cooling_cpufreq_lock); | |
103 | } | |
104 | ||
105 | /* Below code defines functions to be used for cpufreq as cooling device */ | |
106 | ||
107 | /** | |
108 | * is_cpufreq_valid - function to check if a cpu has frequency transition policy. | |
109 | * @cpu: cpu for which check is needed. | |
110 | */ | |
111 | static int is_cpufreq_valid(int cpu) | |
112 | { | |
113 | struct cpufreq_policy policy; | |
114 | return !cpufreq_get_policy(&policy, cpu); | |
115 | } | |
116 | ||
117 | /** | |
118 | * get_cpu_frequency - get the absolute value of frequency from level. | |
119 | * @cpu: cpu for which frequency is fetched. | |
120 | * @level: level of frequency of the CPU | |
121 | * e.g level=1 --> 1st MAX FREQ, LEVEL=2 ---> 2nd MAX FREQ, .... etc | |
122 | */ | |
123 | static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) | |
124 | { | |
125 | int ret = 0, i = 0; | |
126 | unsigned long level_index; | |
127 | bool descend = false; | |
128 | struct cpufreq_frequency_table *table = | |
129 | cpufreq_frequency_get_table(cpu); | |
130 | if (!table) | |
131 | return ret; | |
132 | ||
133 | while (table[i].frequency != CPUFREQ_TABLE_END) { | |
134 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) | |
135 | continue; | |
136 | ||
137 | /*check if table in ascending or descending order*/ | |
138 | if ((table[i + 1].frequency != CPUFREQ_TABLE_END) && | |
139 | (table[i + 1].frequency < table[i].frequency) | |
140 | && !descend) { | |
141 | descend = true; | |
142 | } | |
143 | ||
144 | /*return if level matched and table in descending order*/ | |
145 | if (descend && i == level) | |
146 | return table[i].frequency; | |
147 | i++; | |
148 | } | |
149 | i--; | |
150 | ||
151 | if (level > i || descend) | |
152 | return ret; | |
153 | level_index = i - level; | |
154 | ||
155 | /*Scan the table in reverse order and match the level*/ | |
156 | while (i >= 0) { | |
157 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) | |
158 | continue; | |
159 | /*return if level matched*/ | |
160 | if (i == level_index) | |
161 | return table[i].frequency; | |
162 | i--; | |
163 | } | |
164 | return ret; | |
165 | } | |
166 | ||
167 | /** | |
168 | * cpufreq_apply_cooling - function to apply frequency clipping. | |
169 | * @cpufreq_device: cpufreq_cooling_device pointer containing frequency | |
170 | * clipping data. | |
171 | * @cooling_state: value of the cooling state. | |
172 | */ | |
173 | static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, | |
174 | unsigned long cooling_state) | |
175 | { | |
176 | unsigned int cpuid, clip_freq; | |
177 | struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; | |
178 | unsigned int cpu = cpumask_any(maskPtr); | |
179 | ||
180 | ||
181 | /* Check if the old cooling action is same as new cooling action */ | |
182 | if (cpufreq_device->cpufreq_state == cooling_state) | |
183 | return 0; | |
184 | ||
185 | clip_freq = get_cpu_frequency(cpu, cooling_state); | |
186 | if (!clip_freq) | |
187 | return -EINVAL; | |
188 | ||
189 | cpufreq_device->cpufreq_state = cooling_state; | |
190 | cpufreq_device->cpufreq_val = clip_freq; | |
191 | notify_device = cpufreq_device; | |
192 | ||
193 | for_each_cpu(cpuid, maskPtr) { | |
194 | if (is_cpufreq_valid(cpuid)) | |
195 | cpufreq_update_policy(cpuid); | |
196 | } | |
197 | ||
198 | notify_device = NOTIFY_INVALID; | |
199 | ||
200 | return 0; | |
201 | } | |
202 | ||
203 | /** | |
204 | * cpufreq_thermal_notifier - notifier callback for cpufreq policy change. | |
205 | * @nb: struct notifier_block * with callback info. | |
206 | * @event: value showing cpufreq event for which this function invoked. | |
207 | * @data: callback-specific data | |
208 | */ | |
209 | static int cpufreq_thermal_notifier(struct notifier_block *nb, | |
210 | unsigned long event, void *data) | |
211 | { | |
212 | struct cpufreq_policy *policy = data; | |
213 | unsigned long max_freq = 0; | |
214 | ||
215 | if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID) | |
216 | return 0; | |
217 | ||
218 | if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus)) | |
219 | max_freq = notify_device->cpufreq_val; | |
220 | ||
221 | /* Never exceed user_policy.max*/ | |
222 | if (max_freq > policy->user_policy.max) | |
223 | max_freq = policy->user_policy.max; | |
224 | ||
225 | if (policy->max != max_freq) | |
226 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
227 | ||
228 | return 0; | |
229 | } | |
230 | ||
231 | /* | |
232 | * cpufreq cooling device callback functions are defined below | |
233 | */ | |
234 | ||
235 | /** | |
236 | * cpufreq_get_max_state - callback function to get the max cooling state. | |
237 | * @cdev: thermal cooling device pointer. | |
238 | * @state: fill this variable with the max cooling state. | |
239 | */ | |
240 | static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, | |
241 | unsigned long *state) | |
242 | { | |
243 | int ret = -EINVAL, i = 0; | |
244 | struct cpufreq_cooling_device *cpufreq_device; | |
245 | struct cpumask *maskPtr; | |
246 | unsigned int cpu; | |
247 | struct cpufreq_frequency_table *table; | |
248 | ||
249 | mutex_lock(&cooling_cpufreq_lock); | |
250 | list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { | |
251 | if (cpufreq_device && cpufreq_device->cool_dev == cdev) | |
252 | break; | |
253 | } | |
254 | if (cpufreq_device == NULL) | |
255 | goto return_get_max_state; | |
256 | ||
257 | maskPtr = &cpufreq_device->allowed_cpus; | |
258 | cpu = cpumask_any(maskPtr); | |
259 | table = cpufreq_frequency_get_table(cpu); | |
260 | if (!table) { | |
261 | *state = 0; | |
262 | ret = 0; | |
263 | goto return_get_max_state; | |
264 | } | |
265 | ||
266 | while (table[i].frequency != CPUFREQ_TABLE_END) { | |
267 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) | |
268 | continue; | |
269 | i++; | |
270 | } | |
271 | if (i > 0) { | |
272 | *state = --i; | |
273 | ret = 0; | |
274 | } | |
275 | ||
276 | return_get_max_state: | |
277 | mutex_unlock(&cooling_cpufreq_lock); | |
278 | return ret; | |
279 | } | |
280 | ||
281 | /** | |
282 | * cpufreq_get_cur_state - callback function to get the current cooling state. | |
283 | * @cdev: thermal cooling device pointer. | |
284 | * @state: fill this variable with the current cooling state. | |
285 | */ | |
286 | static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, | |
287 | unsigned long *state) | |
288 | { | |
289 | int ret = -EINVAL; | |
290 | struct cpufreq_cooling_device *cpufreq_device; | |
291 | ||
292 | mutex_lock(&cooling_cpufreq_lock); | |
293 | list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { | |
294 | if (cpufreq_device && cpufreq_device->cool_dev == cdev) { | |
295 | *state = cpufreq_device->cpufreq_state; | |
296 | ret = 0; | |
297 | break; | |
298 | } | |
299 | } | |
300 | mutex_unlock(&cooling_cpufreq_lock); | |
301 | ||
302 | return ret; | |
303 | } | |
304 | ||
305 | /** | |
306 | * cpufreq_set_cur_state - callback function to set the current cooling state. | |
307 | * @cdev: thermal cooling device pointer. | |
308 | * @state: set this variable to the current cooling state. | |
309 | */ | |
310 | static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, | |
311 | unsigned long state) | |
312 | { | |
313 | int ret = -EINVAL; | |
314 | struct cpufreq_cooling_device *cpufreq_device; | |
315 | ||
316 | mutex_lock(&cooling_cpufreq_lock); | |
317 | list_for_each_entry(cpufreq_device, &cooling_cpufreq_list, node) { | |
318 | if (cpufreq_device && cpufreq_device->cool_dev == cdev) { | |
319 | ret = 0; | |
320 | break; | |
321 | } | |
322 | } | |
323 | if (!ret) | |
324 | ret = cpufreq_apply_cooling(cpufreq_device, state); | |
325 | ||
326 | mutex_unlock(&cooling_cpufreq_lock); | |
327 | ||
328 | return ret; | |
329 | } | |
330 | ||
331 | /* Bind cpufreq callbacks to thermal cooling device ops */ | |
332 | static struct thermal_cooling_device_ops const cpufreq_cooling_ops = { | |
333 | .get_max_state = cpufreq_get_max_state, | |
334 | .get_cur_state = cpufreq_get_cur_state, | |
335 | .set_cur_state = cpufreq_set_cur_state, | |
336 | }; | |
337 | ||
338 | /* Notifier for cpufreq policy change */ | |
339 | static struct notifier_block thermal_cpufreq_notifier_block = { | |
340 | .notifier_call = cpufreq_thermal_notifier, | |
341 | }; | |
342 | ||
343 | /** | |
344 | * cpufreq_cooling_register - function to create cpufreq cooling device. | |
345 | * @clip_cpus: cpumask of cpus where the frequency constraints will happen. | |
346 | */ | |
347 | struct thermal_cooling_device *cpufreq_cooling_register( | |
348 | struct cpumask *clip_cpus) | |
349 | { | |
350 | struct thermal_cooling_device *cool_dev; | |
351 | struct cpufreq_cooling_device *cpufreq_dev = NULL; | |
352 | unsigned int cpufreq_dev_count = 0, min = 0, max = 0; | |
353 | char dev_name[THERMAL_NAME_LENGTH]; | |
a4b6fec9 | 354 | int ret = 0, i; |
02361418 ADK |
355 | struct cpufreq_policy policy; |
356 | ||
357 | list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) | |
358 | cpufreq_dev_count++; | |
359 | ||
360 | /*Verify that all the clip cpus have same freq_min, freq_max limit*/ | |
361 | for_each_cpu(i, clip_cpus) { | |
362 | /*continue if cpufreq policy not found and not return error*/ | |
363 | if (!cpufreq_get_policy(&policy, i)) | |
364 | continue; | |
365 | if (min == 0 && max == 0) { | |
366 | min = policy.cpuinfo.min_freq; | |
367 | max = policy.cpuinfo.max_freq; | |
368 | } else { | |
369 | if (min != policy.cpuinfo.min_freq || | |
370 | max != policy.cpuinfo.max_freq) | |
371 | return ERR_PTR(-EINVAL); | |
372 | } | |
373 | } | |
374 | cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device), | |
375 | GFP_KERNEL); | |
376 | if (!cpufreq_dev) | |
377 | return ERR_PTR(-ENOMEM); | |
378 | ||
379 | cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus); | |
380 | ||
381 | if (cpufreq_dev_count == 0) | |
382 | mutex_init(&cooling_cpufreq_lock); | |
383 | ||
384 | ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); | |
385 | if (ret) { | |
386 | kfree(cpufreq_dev); | |
387 | return ERR_PTR(-EINVAL); | |
388 | } | |
389 | ||
390 | sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id); | |
391 | ||
392 | cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev, | |
393 | &cpufreq_cooling_ops); | |
394 | if (!cool_dev) { | |
395 | release_idr(&cpufreq_idr, cpufreq_dev->id); | |
396 | kfree(cpufreq_dev); | |
397 | return ERR_PTR(-EINVAL); | |
398 | } | |
02361418 ADK |
399 | cpufreq_dev->cool_dev = cool_dev; |
400 | cpufreq_dev->cpufreq_state = 0; | |
401 | mutex_lock(&cooling_cpufreq_lock); | |
402 | list_add_tail(&cpufreq_dev->node, &cooling_cpufreq_list); | |
403 | ||
404 | /* Register the notifier for first cpufreq cooling device */ | |
405 | if (cpufreq_dev_count == 0) | |
406 | cpufreq_register_notifier(&thermal_cpufreq_notifier_block, | |
407 | CPUFREQ_POLICY_NOTIFIER); | |
408 | ||
409 | mutex_unlock(&cooling_cpufreq_lock); | |
410 | return cool_dev; | |
411 | } | |
412 | EXPORT_SYMBOL(cpufreq_cooling_register); | |
413 | ||
414 | /** | |
415 | * cpufreq_cooling_unregister - function to remove cpufreq cooling device. | |
416 | * @cdev: thermal cooling device pointer. | |
417 | */ | |
418 | void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) | |
419 | { | |
420 | struct cpufreq_cooling_device *cpufreq_dev = NULL; | |
421 | unsigned int cpufreq_dev_count = 0; | |
422 | ||
423 | mutex_lock(&cooling_cpufreq_lock); | |
424 | list_for_each_entry(cpufreq_dev, &cooling_cpufreq_list, node) { | |
425 | if (cpufreq_dev && cpufreq_dev->cool_dev == cdev) | |
426 | break; | |
427 | cpufreq_dev_count++; | |
428 | } | |
429 | ||
430 | if (!cpufreq_dev || cpufreq_dev->cool_dev != cdev) { | |
431 | mutex_unlock(&cooling_cpufreq_lock); | |
432 | return; | |
433 | } | |
434 | ||
435 | list_del(&cpufreq_dev->node); | |
436 | ||
437 | /* Unregister the notifier for the last cpufreq cooling device */ | |
438 | if (cpufreq_dev_count == 1) { | |
439 | cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, | |
440 | CPUFREQ_POLICY_NOTIFIER); | |
441 | } | |
442 | mutex_unlock(&cooling_cpufreq_lock); | |
443 | thermal_cooling_device_unregister(cpufreq_dev->cool_dev); | |
444 | release_idr(&cpufreq_idr, cpufreq_dev->id); | |
445 | if (cpufreq_dev_count == 1) | |
446 | mutex_destroy(&cooling_cpufreq_lock); | |
447 | kfree(cpufreq_dev); | |
448 | } | |
449 | EXPORT_SYMBOL(cpufreq_cooling_unregister); |