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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); | |
160b7d80 | 61 | static DEFINE_MUTEX(cooling_cpufreq_lock); |
02361418 | 62 | |
160b7d80 | 63 | static unsigned int cpufreq_dev_count; |
02361418 ADK |
64 | |
65 | /* notify_table passes value to the CPUFREQ_ADJUST callback function. */ | |
66 | #define NOTIFY_INVALID NULL | |
a0f846c2 | 67 | static struct cpufreq_cooling_device *notify_device; |
02361418 ADK |
68 | |
69 | /** | |
70 | * get_idr - function to get a unique id. | |
71 | * @idr: struct idr * handle used to create a id. | |
72 | * @id: int * value generated by this function. | |
73 | */ | |
74 | static int get_idr(struct idr *idr, int *id) | |
75 | { | |
6deb69fa | 76 | int ret; |
02361418 ADK |
77 | |
78 | mutex_lock(&cooling_cpufreq_lock); | |
6deb69fa | 79 | ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL); |
02361418 | 80 | mutex_unlock(&cooling_cpufreq_lock); |
6deb69fa TH |
81 | if (unlikely(ret < 0)) |
82 | return ret; | |
83 | *id = ret; | |
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 | /** | |
102 | * is_cpufreq_valid - function to check if a cpu has frequency transition policy. | |
103 | * @cpu: cpu for which check is needed. | |
104 | */ | |
105 | static int is_cpufreq_valid(int cpu) | |
106 | { | |
107 | struct cpufreq_policy policy; | |
108 | return !cpufreq_get_policy(&policy, cpu); | |
109 | } | |
110 | ||
111 | /** | |
112 | * get_cpu_frequency - get the absolute value of frequency from level. | |
113 | * @cpu: cpu for which frequency is fetched. | |
475f41c3 ZR |
114 | * @level: level of frequency, equals cooling state of cpu cooling device |
115 | * e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc | |
02361418 ADK |
116 | */ |
117 | static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) | |
118 | { | |
119 | int ret = 0, i = 0; | |
120 | unsigned long level_index; | |
121 | bool descend = false; | |
122 | struct cpufreq_frequency_table *table = | |
123 | cpufreq_frequency_get_table(cpu); | |
124 | if (!table) | |
125 | return ret; | |
126 | ||
127 | while (table[i].frequency != CPUFREQ_TABLE_END) { | |
128 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) | |
129 | continue; | |
130 | ||
131 | /*check if table in ascending or descending order*/ | |
132 | if ((table[i + 1].frequency != CPUFREQ_TABLE_END) && | |
133 | (table[i + 1].frequency < table[i].frequency) | |
134 | && !descend) { | |
135 | descend = true; | |
136 | } | |
137 | ||
138 | /*return if level matched and table in descending order*/ | |
139 | if (descend && i == level) | |
140 | return table[i].frequency; | |
141 | i++; | |
142 | } | |
143 | i--; | |
144 | ||
145 | if (level > i || descend) | |
146 | return ret; | |
147 | level_index = i - level; | |
148 | ||
149 | /*Scan the table in reverse order and match the level*/ | |
150 | while (i >= 0) { | |
151 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) | |
152 | continue; | |
153 | /*return if level matched*/ | |
154 | if (i == level_index) | |
155 | return table[i].frequency; | |
156 | i--; | |
157 | } | |
158 | return ret; | |
159 | } | |
160 | ||
161 | /** | |
162 | * cpufreq_apply_cooling - function to apply frequency clipping. | |
163 | * @cpufreq_device: cpufreq_cooling_device pointer containing frequency | |
164 | * clipping data. | |
165 | * @cooling_state: value of the cooling state. | |
166 | */ | |
167 | static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device, | |
168 | unsigned long cooling_state) | |
169 | { | |
170 | unsigned int cpuid, clip_freq; | |
171 | struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; | |
172 | unsigned int cpu = cpumask_any(maskPtr); | |
173 | ||
174 | ||
175 | /* Check if the old cooling action is same as new cooling action */ | |
176 | if (cpufreq_device->cpufreq_state == cooling_state) | |
177 | return 0; | |
178 | ||
179 | clip_freq = get_cpu_frequency(cpu, cooling_state); | |
180 | if (!clip_freq) | |
181 | return -EINVAL; | |
182 | ||
183 | cpufreq_device->cpufreq_state = cooling_state; | |
184 | cpufreq_device->cpufreq_val = clip_freq; | |
185 | notify_device = cpufreq_device; | |
186 | ||
187 | for_each_cpu(cpuid, maskPtr) { | |
188 | if (is_cpufreq_valid(cpuid)) | |
189 | cpufreq_update_policy(cpuid); | |
190 | } | |
191 | ||
192 | notify_device = NOTIFY_INVALID; | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
197 | /** | |
198 | * cpufreq_thermal_notifier - notifier callback for cpufreq policy change. | |
199 | * @nb: struct notifier_block * with callback info. | |
200 | * @event: value showing cpufreq event for which this function invoked. | |
201 | * @data: callback-specific data | |
202 | */ | |
203 | static int cpufreq_thermal_notifier(struct notifier_block *nb, | |
204 | unsigned long event, void *data) | |
205 | { | |
206 | struct cpufreq_policy *policy = data; | |
207 | unsigned long max_freq = 0; | |
208 | ||
209 | if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID) | |
210 | return 0; | |
211 | ||
212 | if (cpumask_test_cpu(policy->cpu, ¬ify_device->allowed_cpus)) | |
213 | max_freq = notify_device->cpufreq_val; | |
214 | ||
215 | /* Never exceed user_policy.max*/ | |
216 | if (max_freq > policy->user_policy.max) | |
217 | max_freq = policy->user_policy.max; | |
218 | ||
219 | if (policy->max != max_freq) | |
220 | cpufreq_verify_within_limits(policy, 0, max_freq); | |
221 | ||
222 | return 0; | |
223 | } | |
224 | ||
225 | /* | |
226 | * cpufreq cooling device callback functions are defined below | |
227 | */ | |
228 | ||
229 | /** | |
230 | * cpufreq_get_max_state - callback function to get the max cooling state. | |
231 | * @cdev: thermal cooling device pointer. | |
232 | * @state: fill this variable with the max cooling state. | |
233 | */ | |
234 | static int cpufreq_get_max_state(struct thermal_cooling_device *cdev, | |
235 | unsigned long *state) | |
236 | { | |
160b7d80 | 237 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
238 | struct cpumask *maskPtr = &cpufreq_device->allowed_cpus; | |
02361418 ADK |
239 | unsigned int cpu; |
240 | struct cpufreq_frequency_table *table; | |
9c51b05a | 241 | unsigned long count = 0; |
160b7d80 | 242 | int i = 0; |
02361418 | 243 | |
02361418 ADK |
244 | cpu = cpumask_any(maskPtr); |
245 | table = cpufreq_frequency_get_table(cpu); | |
246 | if (!table) { | |
247 | *state = 0; | |
160b7d80 | 248 | return 0; |
02361418 ADK |
249 | } |
250 | ||
9c51b05a | 251 | for (i = 0; (table[i].frequency != CPUFREQ_TABLE_END); i++) { |
02361418 ADK |
252 | if (table[i].frequency == CPUFREQ_ENTRY_INVALID) |
253 | continue; | |
9c51b05a | 254 | count++; |
02361418 | 255 | } |
9c51b05a | 256 | |
257 | if (count > 0) { | |
258 | *state = --count; | |
160b7d80 | 259 | return 0; |
02361418 ADK |
260 | } |
261 | ||
160b7d80 | 262 | return -EINVAL; |
02361418 ADK |
263 | } |
264 | ||
265 | /** | |
266 | * cpufreq_get_cur_state - callback function to get the current cooling state. | |
267 | * @cdev: thermal cooling device pointer. | |
268 | * @state: fill this variable with the current cooling state. | |
269 | */ | |
270 | static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev, | |
271 | unsigned long *state) | |
272 | { | |
160b7d80 | 273 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
02361418 | 274 | |
160b7d80 | 275 | *state = cpufreq_device->cpufreq_state; |
276 | return 0; | |
02361418 ADK |
277 | } |
278 | ||
279 | /** | |
280 | * cpufreq_set_cur_state - callback function to set the current cooling state. | |
281 | * @cdev: thermal cooling device pointer. | |
282 | * @state: set this variable to the current cooling state. | |
283 | */ | |
284 | static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev, | |
285 | unsigned long state) | |
286 | { | |
160b7d80 | 287 | struct cpufreq_cooling_device *cpufreq_device = cdev->devdata; |
02361418 | 288 | |
160b7d80 | 289 | return cpufreq_apply_cooling(cpufreq_device, state); |
02361418 ADK |
290 | } |
291 | ||
292 | /* Bind cpufreq callbacks to thermal cooling device ops */ | |
293 | static struct thermal_cooling_device_ops const cpufreq_cooling_ops = { | |
294 | .get_max_state = cpufreq_get_max_state, | |
295 | .get_cur_state = cpufreq_get_cur_state, | |
296 | .set_cur_state = cpufreq_set_cur_state, | |
297 | }; | |
298 | ||
299 | /* Notifier for cpufreq policy change */ | |
300 | static struct notifier_block thermal_cpufreq_notifier_block = { | |
301 | .notifier_call = cpufreq_thermal_notifier, | |
302 | }; | |
303 | ||
304 | /** | |
305 | * cpufreq_cooling_register - function to create cpufreq cooling device. | |
306 | * @clip_cpus: cpumask of cpus where the frequency constraints will happen. | |
307 | */ | |
308 | struct thermal_cooling_device *cpufreq_cooling_register( | |
3778ff5c | 309 | const struct cpumask *clip_cpus) |
02361418 ADK |
310 | { |
311 | struct thermal_cooling_device *cool_dev; | |
312 | struct cpufreq_cooling_device *cpufreq_dev = NULL; | |
160b7d80 | 313 | unsigned int min = 0, max = 0; |
02361418 | 314 | char dev_name[THERMAL_NAME_LENGTH]; |
a4b6fec9 | 315 | int ret = 0, i; |
02361418 ADK |
316 | struct cpufreq_policy policy; |
317 | ||
02361418 ADK |
318 | /*Verify that all the clip cpus have same freq_min, freq_max limit*/ |
319 | for_each_cpu(i, clip_cpus) { | |
320 | /*continue if cpufreq policy not found and not return error*/ | |
321 | if (!cpufreq_get_policy(&policy, i)) | |
322 | continue; | |
323 | if (min == 0 && max == 0) { | |
324 | min = policy.cpuinfo.min_freq; | |
325 | max = policy.cpuinfo.max_freq; | |
326 | } else { | |
327 | if (min != policy.cpuinfo.min_freq || | |
328 | max != policy.cpuinfo.max_freq) | |
329 | return ERR_PTR(-EINVAL); | |
6b6519df | 330 | } |
02361418 ADK |
331 | } |
332 | cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device), | |
333 | GFP_KERNEL); | |
334 | if (!cpufreq_dev) | |
335 | return ERR_PTR(-ENOMEM); | |
336 | ||
337 | cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus); | |
338 | ||
02361418 ADK |
339 | ret = get_idr(&cpufreq_idr, &cpufreq_dev->id); |
340 | if (ret) { | |
341 | kfree(cpufreq_dev); | |
342 | return ERR_PTR(-EINVAL); | |
343 | } | |
344 | ||
345 | sprintf(dev_name, "thermal-cpufreq-%d", cpufreq_dev->id); | |
346 | ||
347 | cool_dev = thermal_cooling_device_register(dev_name, cpufreq_dev, | |
348 | &cpufreq_cooling_ops); | |
349 | if (!cool_dev) { | |
350 | release_idr(&cpufreq_idr, cpufreq_dev->id); | |
351 | kfree(cpufreq_dev); | |
352 | return ERR_PTR(-EINVAL); | |
353 | } | |
02361418 ADK |
354 | cpufreq_dev->cool_dev = cool_dev; |
355 | cpufreq_dev->cpufreq_state = 0; | |
356 | mutex_lock(&cooling_cpufreq_lock); | |
02361418 ADK |
357 | |
358 | /* Register the notifier for first cpufreq cooling device */ | |
359 | if (cpufreq_dev_count == 0) | |
360 | cpufreq_register_notifier(&thermal_cpufreq_notifier_block, | |
361 | CPUFREQ_POLICY_NOTIFIER); | |
160b7d80 | 362 | cpufreq_dev_count++; |
02361418 ADK |
363 | |
364 | mutex_unlock(&cooling_cpufreq_lock); | |
365 | return cool_dev; | |
366 | } | |
367 | EXPORT_SYMBOL(cpufreq_cooling_register); | |
368 | ||
369 | /** | |
370 | * cpufreq_cooling_unregister - function to remove cpufreq cooling device. | |
371 | * @cdev: thermal cooling device pointer. | |
372 | */ | |
373 | void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev) | |
374 | { | |
160b7d80 | 375 | struct cpufreq_cooling_device *cpufreq_dev = cdev->devdata; |
02361418 ADK |
376 | |
377 | mutex_lock(&cooling_cpufreq_lock); | |
160b7d80 | 378 | cpufreq_dev_count--; |
02361418 ADK |
379 | |
380 | /* Unregister the notifier for the last cpufreq cooling device */ | |
160b7d80 | 381 | if (cpufreq_dev_count == 0) { |
02361418 ADK |
382 | cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block, |
383 | CPUFREQ_POLICY_NOTIFIER); | |
384 | } | |
385 | mutex_unlock(&cooling_cpufreq_lock); | |
160b7d80 | 386 | |
02361418 ADK |
387 | thermal_cooling_device_unregister(cpufreq_dev->cool_dev); |
388 | release_idr(&cpufreq_idr, cpufreq_dev->id); | |
02361418 ADK |
389 | kfree(cpufreq_dev); |
390 | } | |
391 | EXPORT_SYMBOL(cpufreq_cooling_unregister); |