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Amit Daniel Kachhap02361412012-08-16 17:11:40 +05301/*
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 */
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053023#include <linux/module.h>
24#include <linux/thermal.h>
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053025#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/**
Eduardo Valentin3b3c0742013-04-17 17:11:56 +000032 * struct cpufreq_cooling_device - data for cooling device with cpufreq
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053033 * @id: unique integer value corresponding to each cpufreq_cooling_device
34 * registered.
Eduardo Valentin3b3c0742013-04-17 17:11:56 +000035 * @cool_dev: thermal_cooling_device pointer to keep track of the
36 * registered cooling device.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053037 * @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.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053042 *
43 * This structure is required for keeping information of each
Eduardo Valentin67d0b2a2013-04-17 17:12:19 +000044 * cpufreq_cooling_device registered. In order to prevent corruption of this a
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053045 * mutex lock cooling_cpufreq_lock is used.
46 */
47struct 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;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053053};
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053054static DEFINE_IDR(cpufreq_idr);
hongbo.zhang160b7d82012-10-30 17:48:59 +010055static DEFINE_MUTEX(cooling_cpufreq_lock);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053056
hongbo.zhang160b7d82012-10-30 17:48:59 +010057static unsigned int cpufreq_dev_count;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053058
59/* notify_table passes value to the CPUFREQ_ADJUST callback function. */
60#define NOTIFY_INVALID NULL
Sachin Kamata0f846c2012-11-15 12:19:44 +053061static struct cpufreq_cooling_device *notify_device;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053062
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.
Eduardo Valentin79491e52013-04-17 17:11:59 +000067 *
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.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053072 */
73static int get_idr(struct idr *idr, int *id)
74{
Tejun Heo6deb69f2013-02-27 17:04:46 -080075 int ret;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053076
77 mutex_lock(&cooling_cpufreq_lock);
Tejun Heo6deb69f2013-02-27 17:04:46 -080078 ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053079 mutex_unlock(&cooling_cpufreq_lock);
Tejun Heo6deb69f2013-02-27 17:04:46 -080080 if (unlikely(ret < 0))
81 return ret;
82 *id = ret;
Eduardo Valentin79491e52013-04-17 17:11:59 +000083
Amit Daniel Kachhap02361412012-08-16 17:11:40 +053084 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 */
92static 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/**
Eduardo Valentin82b9ee42013-04-17 17:12:00 +0000102 * is_cpufreq_valid - function to check frequency transitioning capability.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530103 * @cpu: cpu for which check is needed.
Eduardo Valentin82b9ee42013-04-17 17:12:00 +0000104 *
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.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530110 */
111static int is_cpufreq_valid(int cpu)
112{
113 struct cpufreq_policy policy;
Eduardo Valentin79491e52013-04-17 17:11:59 +0000114
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530115 return !cpufreq_get_policy(&policy, cpu);
116}
117
Zhang Ruifc35b352013-02-08 13:09:32 +0800118enum cpufreq_cooling_property {
119 GET_LEVEL,
120 GET_FREQ,
121 GET_MAXL,
122};
123
Eduardo Valentin2d6f28f2013-04-17 17:12:01 +0000124/**
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
Zhang Ruifc35b352013-02-08 13:09:32 +0800132 * 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.
Eduardo Valentin2d6f28f2013-04-17 17:12:01 +0000140 *
141 * Return: 0 on success, -EINVAL when invalid parameters are passed.
142 */
Zhang Ruifc35b352013-02-08 13:09:32 +0800143static int get_property(unsigned int cpu, unsigned long input,
Eduardo Valentind8892a02013-04-17 17:12:03 +0000144 unsigned int *output,
145 enum cpufreq_cooling_property property)
Zhang Ruifc35b352013-02-08 13:09:32 +0800146{
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300147 int i;
Eduardo Valentin4469b992013-04-17 17:11:58 +0000148 unsigned long max_level = 0, level = 0;
Zhang Ruifc35b352013-02-08 13:09:32 +0800149 unsigned int freq = CPUFREQ_ENTRY_INVALID;
150 int descend = -1;
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300151 struct cpufreq_frequency_table *pos, *table =
Zhang Ruifc35b352013-02-08 13:09:32 +0800152 cpufreq_frequency_get_table(cpu);
Eduardo Valentin79d26402013-04-17 17:11:55 +0000153
Zhang Ruifc35b352013-02-08 13:09:32 +0800154 if (!output)
155 return -EINVAL;
156
157 if (!table)
158 return -EINVAL;
159
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300160 cpufreq_for_each_valid_entry(pos, table) {
Zhang Ruifc35b352013-02-08 13:09:32 +0800161 /* ignore duplicate entry */
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300162 if (freq == pos->frequency)
Zhang Ruifc35b352013-02-08 13:09:32 +0800163 continue;
164
165 /* get the frequency order */
Shawn Guo24c7a382013-05-28 06:22:32 +0000166 if (freq != CPUFREQ_ENTRY_INVALID && descend == -1)
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300167 descend = freq > pos->frequency;
Zhang Ruifc35b352013-02-08 13:09:32 +0800168
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300169 freq = pos->frequency;
Zhang Ruifc35b352013-02-08 13:09:32 +0800170 max_level++;
171 }
Zhang Ruia1167762014-01-02 11:57:48 +0800172
173 /* No valid cpu frequency entry */
174 if (max_level == 0)
175 return -EINVAL;
176
Eduardo Valentin1c9573a2013-11-13 14:11:09 -0400177 /* max_level is an index, not a counter */
178 max_level--;
Zhang Ruifc35b352013-02-08 13:09:32 +0800179
180 /* get max level */
181 if (property == GET_MAXL) {
182 *output = (unsigned int)max_level;
183 return 0;
184 }
185
186 if (property == GET_FREQ)
Eduardo Valentin1c9573a2013-11-13 14:11:09 -0400187 level = descend ? input : (max_level - input);
Zhang Ruifc35b352013-02-08 13:09:32 +0800188
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300189 i = 0;
190 cpufreq_for_each_valid_entry(pos, table) {
Zhang Ruifc35b352013-02-08 13:09:32 +0800191 /* ignore duplicate entry */
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300192 if (freq == pos->frequency)
Zhang Ruifc35b352013-02-08 13:09:32 +0800193 continue;
194
195 /* now we have a valid frequency entry */
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300196 freq = pos->frequency;
Zhang Ruifc35b352013-02-08 13:09:32 +0800197
198 if (property == GET_LEVEL && (unsigned int)input == freq) {
199 /* get level by frequency */
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300200 *output = descend ? i : (max_level - i);
Zhang Ruifc35b352013-02-08 13:09:32 +0800201 return 0;
202 }
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300203 if (property == GET_FREQ && level == i) {
Zhang Ruifc35b352013-02-08 13:09:32 +0800204 /* get frequency by level */
205 *output = freq;
206 return 0;
207 }
Stratos Karafotis3c84ef32014-04-25 23:16:39 +0300208 i++;
Zhang Ruifc35b352013-02-08 13:09:32 +0800209 }
Eduardo Valentin79491e52013-04-17 17:11:59 +0000210
Zhang Ruifc35b352013-02-08 13:09:32 +0800211 return -EINVAL;
212}
213
Eduardo Valentin44952d32013-04-17 17:12:05 +0000214/**
215 * cpufreq_cooling_get_level - for a give cpu, return the cooling level.
216 * @cpu: cpu for which the level is required
217 * @freq: the frequency of interest
218 *
219 * This function will match the cooling level corresponding to the
220 * requested @freq and return it.
221 *
222 * Return: The matched cooling level on success or THERMAL_CSTATE_INVALID
223 * otherwise.
224 */
Zhang Rui57df8102013-02-08 14:52:06 +0800225unsigned long cpufreq_cooling_get_level(unsigned int cpu, unsigned int freq)
226{
227 unsigned int val;
228
229 if (get_property(cpu, (unsigned long)freq, &val, GET_LEVEL))
230 return THERMAL_CSTATE_INVALID;
Eduardo Valentin79491e52013-04-17 17:11:59 +0000231
Zhang Rui57df8102013-02-08 14:52:06 +0800232 return (unsigned long)val;
233}
Eduardo Valentin243dbd92013-04-17 17:11:57 +0000234EXPORT_SYMBOL_GPL(cpufreq_cooling_get_level);
Zhang Rui57df8102013-02-08 14:52:06 +0800235
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530236/**
237 * get_cpu_frequency - get the absolute value of frequency from level.
238 * @cpu: cpu for which frequency is fetched.
Eduardo Valentin41518c42013-04-17 17:12:07 +0000239 * @level: cooling level
240 *
241 * This function matches cooling level with frequency. Based on a cooling level
242 * of frequency, equals cooling state of cpu cooling device, it will return
243 * the corresponding frequency.
Zhang Rui475f41c2013-02-06 09:34:32 +0800244 * e.g level=0 --> 1st MAX FREQ, level=1 ---> 2nd MAX FREQ, .... etc
Eduardo Valentin41518c42013-04-17 17:12:07 +0000245 *
246 * Return: 0 on error, the corresponding frequency otherwise.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530247 */
248static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level)
249{
Zhang Ruifc35b352013-02-08 13:09:32 +0800250 int ret = 0;
251 unsigned int freq;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530252
Zhang Ruifc35b352013-02-08 13:09:32 +0800253 ret = get_property(cpu, level, &freq, GET_FREQ);
254 if (ret)
255 return 0;
Eduardo Valentin79491e52013-04-17 17:11:59 +0000256
Zhang Ruifc35b352013-02-08 13:09:32 +0800257 return freq;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530258}
259
260/**
261 * cpufreq_apply_cooling - function to apply frequency clipping.
262 * @cpufreq_device: cpufreq_cooling_device pointer containing frequency
263 * clipping data.
264 * @cooling_state: value of the cooling state.
Eduardo Valentin4b33deb2013-04-17 17:12:08 +0000265 *
266 * Function used to make sure the cpufreq layer is aware of current thermal
267 * limits. The limits are applied by updating the cpufreq policy.
268 *
269 * Return: 0 on success, an error code otherwise (-EINVAL in case wrong
270 * cooling state).
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530271 */
272static int cpufreq_apply_cooling(struct cpufreq_cooling_device *cpufreq_device,
Eduardo Valentin5fda7f62013-04-17 17:12:11 +0000273 unsigned long cooling_state)
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530274{
275 unsigned int cpuid, clip_freq;
Laurent Navet [Mali]bde00662013-03-12 10:47:50 +0000276 struct cpumask *mask = &cpufreq_device->allowed_cpus;
277 unsigned int cpu = cpumask_any(mask);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530278
279
280 /* Check if the old cooling action is same as new cooling action */
281 if (cpufreq_device->cpufreq_state == cooling_state)
282 return 0;
283
284 clip_freq = get_cpu_frequency(cpu, cooling_state);
285 if (!clip_freq)
286 return -EINVAL;
287
288 cpufreq_device->cpufreq_state = cooling_state;
289 cpufreq_device->cpufreq_val = clip_freq;
290 notify_device = cpufreq_device;
291
Laurent Navet [Mali]bde00662013-03-12 10:47:50 +0000292 for_each_cpu(cpuid, mask) {
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530293 if (is_cpufreq_valid(cpuid))
294 cpufreq_update_policy(cpuid);
295 }
296
297 notify_device = NOTIFY_INVALID;
298
299 return 0;
300}
301
302/**
303 * cpufreq_thermal_notifier - notifier callback for cpufreq policy change.
304 * @nb: struct notifier_block * with callback info.
305 * @event: value showing cpufreq event for which this function invoked.
306 * @data: callback-specific data
Eduardo Valentinbab30552013-04-17 17:12:09 +0000307 *
308 * Callback to highjack the notification on cpufreq policy transition.
309 * Every time there is a change in policy, we will intercept and
310 * update the cpufreq policy with thermal constraints.
311 *
312 * Return: 0 (success)
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530313 */
314static int cpufreq_thermal_notifier(struct notifier_block *nb,
Eduardo Valentin5fda7f62013-04-17 17:12:11 +0000315 unsigned long event, void *data)
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530316{
317 struct cpufreq_policy *policy = data;
318 unsigned long max_freq = 0;
319
320 if (event != CPUFREQ_ADJUST || notify_device == NOTIFY_INVALID)
321 return 0;
322
323 if (cpumask_test_cpu(policy->cpu, &notify_device->allowed_cpus))
324 max_freq = notify_device->cpufreq_val;
Lan Tianyu044d5c22013-08-13 10:07:28 +0800325 else
326 return 0;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530327
Eduardo Valentin1b9e3522013-04-17 17:12:02 +0000328 /* Never exceed user_policy.max */
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530329 if (max_freq > policy->user_policy.max)
330 max_freq = policy->user_policy.max;
331
332 if (policy->max != max_freq)
333 cpufreq_verify_within_limits(policy, 0, max_freq);
334
335 return 0;
336}
337
Eduardo Valentin1b9e3522013-04-17 17:12:02 +0000338/* cpufreq cooling device callback functions are defined below */
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530339
340/**
341 * cpufreq_get_max_state - callback function to get the max cooling state.
342 * @cdev: thermal cooling device pointer.
343 * @state: fill this variable with the max cooling state.
Eduardo Valentin62c00422013-04-17 17:12:12 +0000344 *
345 * Callback for the thermal cooling device to return the cpufreq
346 * max cooling state.
347 *
348 * Return: 0 on success, an error code otherwise.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530349 */
350static int cpufreq_get_max_state(struct thermal_cooling_device *cdev,
351 unsigned long *state)
352{
hongbo.zhang160b7d82012-10-30 17:48:59 +0100353 struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
Laurent Navet [Mali]bde00662013-03-12 10:47:50 +0000354 struct cpumask *mask = &cpufreq_device->allowed_cpus;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530355 unsigned int cpu;
Dan Carpenter4f890382013-04-17 07:18:28 +0000356 unsigned int count = 0;
Zhang Ruifc35b352013-02-08 13:09:32 +0800357 int ret;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530358
Laurent Navet [Mali]bde00662013-03-12 10:47:50 +0000359 cpu = cpumask_any(mask);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530360
Dan Carpenter4f890382013-04-17 07:18:28 +0000361 ret = get_property(cpu, 0, &count, GET_MAXL);
hongbo.zhang9c51b052012-10-30 17:48:58 +0100362
Zhang Ruifc35b352013-02-08 13:09:32 +0800363 if (count > 0)
364 *state = count;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530365
Zhang Ruifc35b352013-02-08 13:09:32 +0800366 return ret;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530367}
368
369/**
370 * cpufreq_get_cur_state - callback function to get the current cooling state.
371 * @cdev: thermal cooling device pointer.
372 * @state: fill this variable with the current cooling state.
Eduardo Valentin36725522013-04-17 17:12:13 +0000373 *
374 * Callback for the thermal cooling device to return the cpufreq
375 * current cooling state.
376 *
377 * Return: 0 on success, an error code otherwise.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530378 */
379static int cpufreq_get_cur_state(struct thermal_cooling_device *cdev,
380 unsigned long *state)
381{
hongbo.zhang160b7d82012-10-30 17:48:59 +0100382 struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530383
hongbo.zhang160b7d82012-10-30 17:48:59 +0100384 *state = cpufreq_device->cpufreq_state;
Eduardo Valentin79491e52013-04-17 17:11:59 +0000385
hongbo.zhang160b7d82012-10-30 17:48:59 +0100386 return 0;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530387}
388
389/**
390 * cpufreq_set_cur_state - callback function to set the current cooling state.
391 * @cdev: thermal cooling device pointer.
392 * @state: set this variable to the current cooling state.
Eduardo Valentin56e05fdb2013-04-17 17:12:14 +0000393 *
394 * Callback for the thermal cooling device to change the cpufreq
395 * current cooling state.
396 *
397 * Return: 0 on success, an error code otherwise.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530398 */
399static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
400 unsigned long state)
401{
hongbo.zhang160b7d82012-10-30 17:48:59 +0100402 struct cpufreq_cooling_device *cpufreq_device = cdev->devdata;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530403
hongbo.zhang160b7d82012-10-30 17:48:59 +0100404 return cpufreq_apply_cooling(cpufreq_device, state);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530405}
406
407/* Bind cpufreq callbacks to thermal cooling device ops */
408static struct thermal_cooling_device_ops const cpufreq_cooling_ops = {
409 .get_max_state = cpufreq_get_max_state,
410 .get_cur_state = cpufreq_get_cur_state,
411 .set_cur_state = cpufreq_set_cur_state,
412};
413
414/* Notifier for cpufreq policy change */
415static struct notifier_block thermal_cpufreq_notifier_block = {
416 .notifier_call = cpufreq_thermal_notifier,
417};
418
419/**
Eduardo Valentin39d99cf2013-09-12 19:26:45 -0400420 * __cpufreq_cooling_register - helper function to create cpufreq cooling device
421 * @np: a valid struct device_node to the cooling device device tree node
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530422 * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
Eduardo Valentin12cb08b2013-04-17 17:12:15 +0000423 *
424 * This interface function registers the cpufreq cooling device with the name
425 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
Eduardo Valentin39d99cf2013-09-12 19:26:45 -0400426 * cooling devices. It also gives the opportunity to link the cooling device
427 * with a device tree node, in order to bind it via the thermal DT code.
Eduardo Valentin12cb08b2013-04-17 17:12:15 +0000428 *
429 * Return: a valid struct thermal_cooling_device pointer on success,
430 * on failure, it returns a corresponding ERR_PTR().
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530431 */
Eduardo Valentin39d99cf2013-09-12 19:26:45 -0400432static struct thermal_cooling_device *
433__cpufreq_cooling_register(struct device_node *np,
434 const struct cpumask *clip_cpus)
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530435{
436 struct thermal_cooling_device *cool_dev;
437 struct cpufreq_cooling_device *cpufreq_dev = NULL;
hongbo.zhang160b7d82012-10-30 17:48:59 +0100438 unsigned int min = 0, max = 0;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530439 char dev_name[THERMAL_NAME_LENGTH];
Jonghwa Leea4b6fec2012-09-26 09:43:31 +0900440 int ret = 0, i;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530441 struct cpufreq_policy policy;
442
Eduardo Valentin1b9e3522013-04-17 17:12:02 +0000443 /* Verify that all the clip cpus have same freq_min, freq_max limit */
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530444 for_each_cpu(i, clip_cpus) {
Eduardo Valentin1b9e3522013-04-17 17:12:02 +0000445 /* continue if cpufreq policy not found and not return error */
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530446 if (!cpufreq_get_policy(&policy, i))
447 continue;
448 if (min == 0 && max == 0) {
449 min = policy.cpuinfo.min_freq;
450 max = policy.cpuinfo.max_freq;
451 } else {
452 if (min != policy.cpuinfo.min_freq ||
Eduardo Valentin5fda7f62013-04-17 17:12:11 +0000453 max != policy.cpuinfo.max_freq)
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530454 return ERR_PTR(-EINVAL);
hongbo.zhang6b6519d2012-10-30 17:48:57 +0100455 }
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530456 }
457 cpufreq_dev = kzalloc(sizeof(struct cpufreq_cooling_device),
Eduardo Valentin5fda7f62013-04-17 17:12:11 +0000458 GFP_KERNEL);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530459 if (!cpufreq_dev)
460 return ERR_PTR(-ENOMEM);
461
462 cpumask_copy(&cpufreq_dev->allowed_cpus, clip_cpus);
463
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530464 ret = get_idr(&cpufreq_idr, &cpufreq_dev->id);
465 if (ret) {
466 kfree(cpufreq_dev);
467 return ERR_PTR(-EINVAL);
468 }
469
Eduardo Valentin99871a72013-04-17 17:12:17 +0000470 snprintf(dev_name, sizeof(dev_name), "thermal-cpufreq-%d",
471 cpufreq_dev->id);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530472
Eduardo Valentin39d99cf2013-09-12 19:26:45 -0400473 cool_dev = thermal_of_cooling_device_register(np, dev_name, cpufreq_dev,
474 &cpufreq_cooling_ops);
Wei Yongjun73b9bcd2013-10-25 21:55:42 +0800475 if (IS_ERR(cool_dev)) {
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530476 release_idr(&cpufreq_idr, cpufreq_dev->id);
477 kfree(cpufreq_dev);
Wei Yongjun73b9bcd2013-10-25 21:55:42 +0800478 return cool_dev;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530479 }
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530480 cpufreq_dev->cool_dev = cool_dev;
481 cpufreq_dev->cpufreq_state = 0;
482 mutex_lock(&cooling_cpufreq_lock);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530483
484 /* Register the notifier for first cpufreq cooling device */
485 if (cpufreq_dev_count == 0)
486 cpufreq_register_notifier(&thermal_cpufreq_notifier_block,
Eduardo Valentin5fda7f62013-04-17 17:12:11 +0000487 CPUFREQ_POLICY_NOTIFIER);
hongbo.zhang160b7d82012-10-30 17:48:59 +0100488 cpufreq_dev_count++;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530489
490 mutex_unlock(&cooling_cpufreq_lock);
Eduardo Valentin79491e52013-04-17 17:11:59 +0000491
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530492 return cool_dev;
493}
Eduardo Valentin39d99cf2013-09-12 19:26:45 -0400494
495/**
496 * cpufreq_cooling_register - function to create cpufreq cooling device.
497 * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
498 *
499 * This interface function registers the cpufreq cooling device with the name
500 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
501 * cooling devices.
502 *
503 * Return: a valid struct thermal_cooling_device pointer on success,
504 * on failure, it returns a corresponding ERR_PTR().
505 */
506struct thermal_cooling_device *
507cpufreq_cooling_register(const struct cpumask *clip_cpus)
508{
509 return __cpufreq_cooling_register(NULL, clip_cpus);
510}
Eduardo Valentin243dbd92013-04-17 17:11:57 +0000511EXPORT_SYMBOL_GPL(cpufreq_cooling_register);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530512
513/**
Eduardo Valentin39d99cf2013-09-12 19:26:45 -0400514 * of_cpufreq_cooling_register - function to create cpufreq cooling device.
515 * @np: a valid struct device_node to the cooling device device tree node
516 * @clip_cpus: cpumask of cpus where the frequency constraints will happen.
517 *
518 * This interface function registers the cpufreq cooling device with the name
519 * "thermal-cpufreq-%x". This api can support multiple instances of cpufreq
520 * cooling devices. Using this API, the cpufreq cooling device will be
521 * linked to the device tree node provided.
522 *
523 * Return: a valid struct thermal_cooling_device pointer on success,
524 * on failure, it returns a corresponding ERR_PTR().
525 */
526struct thermal_cooling_device *
527of_cpufreq_cooling_register(struct device_node *np,
528 const struct cpumask *clip_cpus)
529{
530 if (!np)
531 return ERR_PTR(-EINVAL);
532
533 return __cpufreq_cooling_register(np, clip_cpus);
534}
535EXPORT_SYMBOL_GPL(of_cpufreq_cooling_register);
536
537/**
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530538 * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
539 * @cdev: thermal cooling device pointer.
Eduardo Valentin135266b2013-04-17 17:12:16 +0000540 *
541 * This interface function unregisters the "thermal-cpufreq-%x" cooling device.
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530542 */
543void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
544{
Eduardo Valentin50e66c72013-08-15 10:54:46 -0400545 struct cpufreq_cooling_device *cpufreq_dev;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530546
Eduardo Valentin50e66c72013-08-15 10:54:46 -0400547 if (!cdev)
548 return;
549
550 cpufreq_dev = cdev->devdata;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530551 mutex_lock(&cooling_cpufreq_lock);
hongbo.zhang160b7d82012-10-30 17:48:59 +0100552 cpufreq_dev_count--;
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530553
554 /* Unregister the notifier for the last cpufreq cooling device */
Eduardo Valentin2d9bf712013-04-17 17:12:18 +0000555 if (cpufreq_dev_count == 0)
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530556 cpufreq_unregister_notifier(&thermal_cpufreq_notifier_block,
Eduardo Valentin5fda7f62013-04-17 17:12:11 +0000557 CPUFREQ_POLICY_NOTIFIER);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530558 mutex_unlock(&cooling_cpufreq_lock);
hongbo.zhang160b7d82012-10-30 17:48:59 +0100559
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530560 thermal_cooling_device_unregister(cpufreq_dev->cool_dev);
561 release_idr(&cpufreq_idr, cpufreq_dev->id);
Amit Daniel Kachhap02361412012-08-16 17:11:40 +0530562 kfree(cpufreq_dev);
563}
Eduardo Valentin243dbd92013-04-17 17:11:57 +0000564EXPORT_SYMBOL_GPL(cpufreq_cooling_unregister);