]>
Commit | Line | Data |
---|---|---|
a76caf55 ØE |
1 | /* |
2 | * devfreq_cooling: Thermal cooling device implementation for devices using | |
3 | * devfreq | |
4 | * | |
5 | * Copyright (C) 2014-2015 ARM Limited | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
12 | * kind, whether express or implied; without even the implied warranty | |
13 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * TODO: | |
17 | * - If OPPs are added or removed after devfreq cooling has | |
18 | * registered, the devfreq cooling won't react to it. | |
19 | */ | |
20 | ||
21 | #include <linux/devfreq.h> | |
22 | #include <linux/devfreq_cooling.h> | |
23 | #include <linux/export.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/pm_opp.h> | |
26 | #include <linux/thermal.h> | |
27 | ||
9876b1a4 JM |
28 | #include <trace/events/thermal.h> |
29 | ||
a76caf55 ØE |
30 | static DEFINE_MUTEX(devfreq_lock); |
31 | static DEFINE_IDR(devfreq_idr); | |
32 | ||
33 | /** | |
34 | * struct devfreq_cooling_device - Devfreq cooling device | |
35 | * @id: unique integer value corresponding to each | |
36 | * devfreq_cooling_device registered. | |
37 | * @cdev: Pointer to associated thermal cooling device. | |
38 | * @devfreq: Pointer to associated devfreq device. | |
39 | * @cooling_state: Current cooling state. | |
40 | * @power_table: Pointer to table with maximum power draw for each | |
41 | * cooling state. State is the index into the table, and | |
42 | * the power is in mW. | |
43 | * @freq_table: Pointer to a table with the frequencies sorted in descending | |
44 | * order. You can index the table by cooling device state | |
45 | * @freq_table_size: Size of the @freq_table and @power_table | |
46 | * @power_ops: Pointer to devfreq_cooling_power, used to generate the | |
47 | * @power_table. | |
48 | */ | |
49 | struct devfreq_cooling_device { | |
50 | int id; | |
51 | struct thermal_cooling_device *cdev; | |
52 | struct devfreq *devfreq; | |
53 | unsigned long cooling_state; | |
54 | u32 *power_table; | |
55 | u32 *freq_table; | |
56 | size_t freq_table_size; | |
57 | struct devfreq_cooling_power *power_ops; | |
58 | }; | |
59 | ||
60 | /** | |
61 | * get_idr - function to get a unique id. | |
62 | * @idr: struct idr * handle used to create a id. | |
63 | * @id: int * value generated by this function. | |
64 | * | |
65 | * This function will populate @id with an unique | |
66 | * id, using the idr API. | |
67 | * | |
68 | * Return: 0 on success, an error code on failure. | |
69 | */ | |
70 | static int get_idr(struct idr *idr, int *id) | |
71 | { | |
72 | int ret; | |
73 | ||
74 | mutex_lock(&devfreq_lock); | |
75 | ret = idr_alloc(idr, NULL, 0, 0, GFP_KERNEL); | |
76 | mutex_unlock(&devfreq_lock); | |
77 | if (unlikely(ret < 0)) | |
78 | return ret; | |
79 | *id = ret; | |
80 | ||
81 | return 0; | |
82 | } | |
83 | ||
84 | /** | |
85 | * release_idr - function to free the unique id. | |
86 | * @idr: struct idr * handle used for creating the id. | |
87 | * @id: int value representing the unique id. | |
88 | */ | |
89 | static void release_idr(struct idr *idr, int id) | |
90 | { | |
91 | mutex_lock(&devfreq_lock); | |
92 | idr_remove(idr, id); | |
93 | mutex_unlock(&devfreq_lock); | |
94 | } | |
95 | ||
96 | /** | |
97 | * partition_enable_opps() - disable all opps above a given state | |
98 | * @dfc: Pointer to devfreq we are operating on | |
99 | * @cdev_state: cooling device state we're setting | |
100 | * | |
101 | * Go through the OPPs of the device, enabling all OPPs until | |
102 | * @cdev_state and disabling those frequencies above it. | |
103 | */ | |
104 | static int partition_enable_opps(struct devfreq_cooling_device *dfc, | |
105 | unsigned long cdev_state) | |
106 | { | |
107 | int i; | |
108 | struct device *dev = dfc->devfreq->dev.parent; | |
109 | ||
110 | for (i = 0; i < dfc->freq_table_size; i++) { | |
111 | struct dev_pm_opp *opp; | |
112 | int ret = 0; | |
113 | unsigned int freq = dfc->freq_table[i]; | |
114 | bool want_enable = i >= cdev_state ? true : false; | |
115 | ||
116 | rcu_read_lock(); | |
117 | opp = dev_pm_opp_find_freq_exact(dev, freq, !want_enable); | |
118 | rcu_read_unlock(); | |
119 | ||
120 | if (PTR_ERR(opp) == -ERANGE) | |
121 | continue; | |
122 | else if (IS_ERR(opp)) | |
123 | return PTR_ERR(opp); | |
124 | ||
125 | if (want_enable) | |
126 | ret = dev_pm_opp_enable(dev, freq); | |
127 | else | |
128 | ret = dev_pm_opp_disable(dev, freq); | |
129 | ||
130 | if (ret) | |
131 | return ret; | |
132 | } | |
133 | ||
134 | return 0; | |
135 | } | |
136 | ||
137 | static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev, | |
138 | unsigned long *state) | |
139 | { | |
140 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
141 | ||
142 | *state = dfc->freq_table_size - 1; | |
143 | ||
144 | return 0; | |
145 | } | |
146 | ||
147 | static int devfreq_cooling_get_cur_state(struct thermal_cooling_device *cdev, | |
148 | unsigned long *state) | |
149 | { | |
150 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
151 | ||
152 | *state = dfc->cooling_state; | |
153 | ||
154 | return 0; | |
155 | } | |
156 | ||
157 | static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev, | |
158 | unsigned long state) | |
159 | { | |
160 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
161 | struct devfreq *df = dfc->devfreq; | |
162 | struct device *dev = df->dev.parent; | |
163 | int ret; | |
164 | ||
165 | if (state == dfc->cooling_state) | |
166 | return 0; | |
167 | ||
168 | dev_dbg(dev, "Setting cooling state %lu\n", state); | |
169 | ||
170 | if (state >= dfc->freq_table_size) | |
171 | return -EINVAL; | |
172 | ||
173 | ret = partition_enable_opps(dfc, state); | |
174 | if (ret) | |
175 | return ret; | |
176 | ||
177 | dfc->cooling_state = state; | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | /** | |
183 | * freq_get_state() - get the cooling state corresponding to a frequency | |
184 | * @dfc: Pointer to devfreq cooling device | |
185 | * @freq: frequency in Hz | |
186 | * | |
187 | * Return: the cooling state associated with the @freq, or | |
188 | * THERMAL_CSTATE_INVALID if it wasn't found. | |
189 | */ | |
190 | static unsigned long | |
191 | freq_get_state(struct devfreq_cooling_device *dfc, unsigned long freq) | |
192 | { | |
193 | int i; | |
194 | ||
195 | for (i = 0; i < dfc->freq_table_size; i++) { | |
196 | if (dfc->freq_table[i] == freq) | |
197 | return i; | |
198 | } | |
199 | ||
200 | return THERMAL_CSTATE_INVALID; | |
201 | } | |
202 | ||
203 | /** | |
204 | * get_static_power() - calculate the static power | |
205 | * @dfc: Pointer to devfreq cooling device | |
206 | * @freq: Frequency in Hz | |
207 | * | |
208 | * Calculate the static power in milliwatts using the supplied | |
209 | * get_static_power(). The current voltage is calculated using the | |
210 | * OPP library. If no get_static_power() was supplied, assume the | |
211 | * static power is negligible. | |
212 | */ | |
213 | static unsigned long | |
214 | get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq) | |
215 | { | |
216 | struct devfreq *df = dfc->devfreq; | |
217 | struct device *dev = df->dev.parent; | |
218 | unsigned long voltage; | |
219 | struct dev_pm_opp *opp; | |
220 | ||
221 | if (!dfc->power_ops->get_static_power) | |
222 | return 0; | |
223 | ||
224 | rcu_read_lock(); | |
225 | ||
226 | opp = dev_pm_opp_find_freq_exact(dev, freq, true); | |
227 | if (IS_ERR(opp) && (PTR_ERR(opp) == -ERANGE)) | |
228 | opp = dev_pm_opp_find_freq_exact(dev, freq, false); | |
229 | ||
230 | voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */ | |
231 | ||
232 | rcu_read_unlock(); | |
233 | ||
234 | if (voltage == 0) { | |
235 | dev_warn_ratelimited(dev, | |
236 | "Failed to get voltage for frequency %lu: %ld\n", | |
237 | freq, IS_ERR(opp) ? PTR_ERR(opp) : 0); | |
238 | return 0; | |
239 | } | |
240 | ||
241 | return dfc->power_ops->get_static_power(voltage); | |
242 | } | |
243 | ||
244 | /** | |
245 | * get_dynamic_power - calculate the dynamic power | |
246 | * @dfc: Pointer to devfreq cooling device | |
247 | * @freq: Frequency in Hz | |
248 | * @voltage: Voltage in millivolts | |
249 | * | |
250 | * Calculate the dynamic power in milliwatts consumed by the device at | |
251 | * frequency @freq and voltage @voltage. If the get_dynamic_power() | |
252 | * was supplied as part of the devfreq_cooling_power struct, then that | |
253 | * function is used. Otherwise, a simple power model (Pdyn = Coeff * | |
254 | * Voltage^2 * Frequency) is used. | |
255 | */ | |
256 | static unsigned long | |
257 | get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq, | |
258 | unsigned long voltage) | |
259 | { | |
61c8e8aa | 260 | u64 power; |
a76caf55 ØE |
261 | u32 freq_mhz; |
262 | struct devfreq_cooling_power *dfc_power = dfc->power_ops; | |
263 | ||
264 | if (dfc_power->get_dynamic_power) | |
265 | return dfc_power->get_dynamic_power(freq, voltage); | |
266 | ||
267 | freq_mhz = freq / 1000000; | |
268 | power = (u64)dfc_power->dyn_power_coeff * freq_mhz * voltage * voltage; | |
269 | do_div(power, 1000000000); | |
270 | ||
271 | return power; | |
272 | } | |
273 | ||
274 | static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev, | |
275 | struct thermal_zone_device *tz, | |
276 | u32 *power) | |
277 | { | |
278 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
279 | struct devfreq *df = dfc->devfreq; | |
280 | struct devfreq_dev_status *status = &df->last_status; | |
281 | unsigned long state; | |
282 | unsigned long freq = status->current_frequency; | |
283 | u32 dyn_power, static_power; | |
284 | ||
285 | /* Get dynamic power for state */ | |
286 | state = freq_get_state(dfc, freq); | |
287 | if (state == THERMAL_CSTATE_INVALID) | |
288 | return -EAGAIN; | |
289 | ||
290 | dyn_power = dfc->power_table[state]; | |
291 | ||
292 | /* Scale dynamic power for utilization */ | |
293 | dyn_power = (dyn_power * status->busy_time) / status->total_time; | |
294 | ||
295 | /* Get static power */ | |
296 | static_power = get_static_power(dfc, freq); | |
297 | ||
9876b1a4 JM |
298 | trace_thermal_power_devfreq_get_power(cdev, status, freq, dyn_power, |
299 | static_power); | |
300 | ||
a76caf55 ØE |
301 | *power = dyn_power + static_power; |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev, | |
307 | struct thermal_zone_device *tz, | |
308 | unsigned long state, | |
309 | u32 *power) | |
310 | { | |
311 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
312 | unsigned long freq; | |
313 | u32 static_power; | |
314 | ||
315 | if (state < 0 || state >= dfc->freq_table_size) | |
316 | return -EINVAL; | |
317 | ||
318 | freq = dfc->freq_table[state]; | |
319 | static_power = get_static_power(dfc, freq); | |
320 | ||
321 | *power = dfc->power_table[state] + static_power; | |
322 | return 0; | |
323 | } | |
324 | ||
325 | static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev, | |
326 | struct thermal_zone_device *tz, | |
327 | u32 power, unsigned long *state) | |
328 | { | |
329 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
330 | struct devfreq *df = dfc->devfreq; | |
331 | struct devfreq_dev_status *status = &df->last_status; | |
332 | unsigned long freq = status->current_frequency; | |
333 | unsigned long busy_time; | |
334 | s32 dyn_power; | |
335 | u32 static_power; | |
336 | int i; | |
337 | ||
338 | static_power = get_static_power(dfc, freq); | |
339 | ||
340 | dyn_power = power - static_power; | |
341 | dyn_power = dyn_power > 0 ? dyn_power : 0; | |
342 | ||
343 | /* Scale dynamic power for utilization */ | |
344 | busy_time = status->busy_time ?: 1; | |
345 | dyn_power = (dyn_power * status->total_time) / busy_time; | |
346 | ||
347 | /* | |
348 | * Find the first cooling state that is within the power | |
349 | * budget for dynamic power. | |
350 | */ | |
351 | for (i = 0; i < dfc->freq_table_size - 1; i++) | |
352 | if (dyn_power >= dfc->power_table[i]) | |
353 | break; | |
354 | ||
355 | *state = i; | |
9876b1a4 | 356 | trace_thermal_power_devfreq_limit(cdev, freq, *state, power); |
a76caf55 ØE |
357 | return 0; |
358 | } | |
359 | ||
360 | static struct thermal_cooling_device_ops devfreq_cooling_ops = { | |
361 | .get_max_state = devfreq_cooling_get_max_state, | |
362 | .get_cur_state = devfreq_cooling_get_cur_state, | |
363 | .set_cur_state = devfreq_cooling_set_cur_state, | |
364 | }; | |
365 | ||
366 | /** | |
367 | * devfreq_cooling_gen_tables() - Generate power and freq tables. | |
368 | * @dfc: Pointer to devfreq cooling device. | |
369 | * | |
370 | * Generate power and frequency tables: the power table hold the | |
371 | * device's maximum power usage at each cooling state (OPP). The | |
372 | * static and dynamic power using the appropriate voltage and | |
373 | * frequency for the state, is acquired from the struct | |
374 | * devfreq_cooling_power, and summed to make the maximum power draw. | |
375 | * | |
376 | * The frequency table holds the frequencies in descending order. | |
377 | * That way its indexed by cooling device state. | |
378 | * | |
379 | * The tables are malloced, and pointers put in dfc. They must be | |
380 | * freed when unregistering the devfreq cooling device. | |
381 | * | |
382 | * Return: 0 on success, negative error code on failure. | |
383 | */ | |
384 | static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc) | |
385 | { | |
386 | struct devfreq *df = dfc->devfreq; | |
387 | struct device *dev = df->dev.parent; | |
388 | int ret, num_opps; | |
389 | unsigned long freq; | |
390 | u32 *power_table = NULL; | |
391 | u32 *freq_table; | |
392 | int i; | |
393 | ||
394 | num_opps = dev_pm_opp_get_opp_count(dev); | |
395 | ||
396 | if (dfc->power_ops) { | |
397 | power_table = kcalloc(num_opps, sizeof(*power_table), | |
398 | GFP_KERNEL); | |
399 | if (!power_table) | |
400 | ret = -ENOMEM; | |
401 | } | |
402 | ||
403 | freq_table = kcalloc(num_opps, sizeof(*freq_table), | |
404 | GFP_KERNEL); | |
405 | if (!freq_table) { | |
406 | ret = -ENOMEM; | |
407 | goto free_power_table; | |
408 | } | |
409 | ||
410 | for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) { | |
411 | unsigned long power_dyn, voltage; | |
412 | struct dev_pm_opp *opp; | |
413 | ||
414 | rcu_read_lock(); | |
415 | ||
416 | opp = dev_pm_opp_find_freq_floor(dev, &freq); | |
417 | if (IS_ERR(opp)) { | |
418 | rcu_read_unlock(); | |
419 | ret = PTR_ERR(opp); | |
420 | goto free_tables; | |
421 | } | |
422 | ||
423 | voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */ | |
424 | ||
425 | rcu_read_unlock(); | |
426 | ||
427 | if (dfc->power_ops) { | |
428 | power_dyn = get_dynamic_power(dfc, freq, voltage); | |
429 | ||
430 | dev_dbg(dev, "Dynamic power table: %lu MHz @ %lu mV: %lu = %lu mW\n", | |
431 | freq / 1000000, voltage, power_dyn, power_dyn); | |
432 | ||
433 | power_table[i] = power_dyn; | |
434 | } | |
435 | ||
436 | freq_table[i] = freq; | |
437 | } | |
438 | ||
439 | if (dfc->power_ops) | |
440 | dfc->power_table = power_table; | |
441 | ||
442 | dfc->freq_table = freq_table; | |
443 | dfc->freq_table_size = num_opps; | |
444 | ||
445 | return 0; | |
446 | ||
447 | free_tables: | |
448 | kfree(freq_table); | |
449 | free_power_table: | |
450 | kfree(power_table); | |
451 | ||
452 | return ret; | |
453 | } | |
454 | ||
455 | /** | |
456 | * of_devfreq_cooling_register_power() - Register devfreq cooling device, | |
457 | * with OF and power information. | |
458 | * @np: Pointer to OF device_node. | |
459 | * @df: Pointer to devfreq device. | |
460 | * @dfc_power: Pointer to devfreq_cooling_power. | |
461 | * | |
462 | * Register a devfreq cooling device. The available OPPs must be | |
463 | * registered on the device. | |
464 | * | |
465 | * If @dfc_power is provided, the cooling device is registered with the | |
466 | * power extensions. For the power extensions to work correctly, | |
467 | * devfreq should use the simple_ondemand governor, other governors | |
468 | * are not currently supported. | |
469 | */ | |
3c99c2ce | 470 | struct thermal_cooling_device * |
a76caf55 ØE |
471 | of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, |
472 | struct devfreq_cooling_power *dfc_power) | |
473 | { | |
474 | struct thermal_cooling_device *cdev; | |
475 | struct devfreq_cooling_device *dfc; | |
476 | char dev_name[THERMAL_NAME_LENGTH]; | |
477 | int err; | |
478 | ||
479 | dfc = kzalloc(sizeof(*dfc), GFP_KERNEL); | |
480 | if (!dfc) | |
481 | return ERR_PTR(-ENOMEM); | |
482 | ||
483 | dfc->devfreq = df; | |
484 | ||
485 | if (dfc_power) { | |
486 | dfc->power_ops = dfc_power; | |
487 | ||
488 | devfreq_cooling_ops.get_requested_power = | |
489 | devfreq_cooling_get_requested_power; | |
490 | devfreq_cooling_ops.state2power = devfreq_cooling_state2power; | |
491 | devfreq_cooling_ops.power2state = devfreq_cooling_power2state; | |
492 | } | |
493 | ||
494 | err = devfreq_cooling_gen_tables(dfc); | |
495 | if (err) | |
496 | goto free_dfc; | |
497 | ||
498 | err = get_idr(&devfreq_idr, &dfc->id); | |
499 | if (err) | |
500 | goto free_tables; | |
501 | ||
502 | snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id); | |
503 | ||
504 | cdev = thermal_of_cooling_device_register(np, dev_name, dfc, | |
505 | &devfreq_cooling_ops); | |
506 | if (IS_ERR(cdev)) { | |
507 | err = PTR_ERR(cdev); | |
508 | dev_err(df->dev.parent, | |
509 | "Failed to register devfreq cooling device (%d)\n", | |
510 | err); | |
511 | goto release_idr; | |
512 | } | |
513 | ||
514 | dfc->cdev = cdev; | |
515 | ||
3c99c2ce | 516 | return cdev; |
a76caf55 ØE |
517 | |
518 | release_idr: | |
519 | release_idr(&devfreq_idr, dfc->id); | |
520 | free_tables: | |
521 | kfree(dfc->power_table); | |
522 | kfree(dfc->freq_table); | |
523 | free_dfc: | |
524 | kfree(dfc); | |
525 | ||
526 | return ERR_PTR(err); | |
527 | } | |
528 | EXPORT_SYMBOL_GPL(of_devfreq_cooling_register_power); | |
529 | ||
530 | /** | |
531 | * of_devfreq_cooling_register() - Register devfreq cooling device, | |
532 | * with OF information. | |
533 | * @np: Pointer to OF device_node. | |
534 | * @df: Pointer to devfreq device. | |
535 | */ | |
3c99c2ce | 536 | struct thermal_cooling_device * |
a76caf55 ØE |
537 | of_devfreq_cooling_register(struct device_node *np, struct devfreq *df) |
538 | { | |
539 | return of_devfreq_cooling_register_power(np, df, NULL); | |
540 | } | |
541 | EXPORT_SYMBOL_GPL(of_devfreq_cooling_register); | |
542 | ||
543 | /** | |
544 | * devfreq_cooling_register() - Register devfreq cooling device. | |
545 | * @df: Pointer to devfreq device. | |
546 | */ | |
3c99c2ce | 547 | struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df) |
a76caf55 ØE |
548 | { |
549 | return of_devfreq_cooling_register(NULL, df); | |
550 | } | |
551 | EXPORT_SYMBOL_GPL(devfreq_cooling_register); | |
552 | ||
553 | /** | |
554 | * devfreq_cooling_unregister() - Unregister devfreq cooling device. | |
555 | * @dfc: Pointer to devfreq cooling device to unregister. | |
556 | */ | |
3c99c2ce | 557 | void devfreq_cooling_unregister(struct thermal_cooling_device *cdev) |
a76caf55 | 558 | { |
3c99c2ce JM |
559 | struct devfreq_cooling_device *dfc; |
560 | ||
561 | if (!cdev) | |
a76caf55 ØE |
562 | return; |
563 | ||
3c99c2ce JM |
564 | dfc = cdev->devdata; |
565 | ||
a76caf55 ØE |
566 | thermal_cooling_device_unregister(dfc->cdev); |
567 | release_idr(&devfreq_idr, dfc->id); | |
568 | kfree(dfc->power_table); | |
569 | kfree(dfc->freq_table); | |
570 | ||
571 | kfree(dfc); | |
572 | } | |
573 | EXPORT_SYMBOL_GPL(devfreq_cooling_unregister); |