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6b775e87 JM |
1 | /* |
2 | * A power allocator to manage temperature | |
3 | * | |
4 | * Copyright (C) 2014 ARM Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
11 | * kind, whether express or implied; without even the implied warranty | |
12 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | */ | |
15 | ||
16 | #define pr_fmt(fmt) "Power allocator: " fmt | |
17 | ||
18 | #include <linux/rculist.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/thermal.h> | |
21 | ||
6828a471 JM |
22 | #define CREATE_TRACE_POINTS |
23 | #include <trace/events/thermal_power_allocator.h> | |
24 | ||
6b775e87 JM |
25 | #include "thermal_core.h" |
26 | ||
27 | #define FRAC_BITS 10 | |
28 | #define int_to_frac(x) ((x) << FRAC_BITS) | |
29 | #define frac_to_int(x) ((x) >> FRAC_BITS) | |
30 | ||
31 | /** | |
32 | * mul_frac() - multiply two fixed-point numbers | |
33 | * @x: first multiplicand | |
34 | * @y: second multiplicand | |
35 | * | |
36 | * Return: the result of multiplying two fixed-point numbers. The | |
37 | * result is also a fixed-point number. | |
38 | */ | |
39 | static inline s64 mul_frac(s64 x, s64 y) | |
40 | { | |
41 | return (x * y) >> FRAC_BITS; | |
42 | } | |
43 | ||
44 | /** | |
45 | * div_frac() - divide two fixed-point numbers | |
46 | * @x: the dividend | |
47 | * @y: the divisor | |
48 | * | |
49 | * Return: the result of dividing two fixed-point numbers. The | |
50 | * result is also a fixed-point number. | |
51 | */ | |
52 | static inline s64 div_frac(s64 x, s64 y) | |
53 | { | |
54 | return div_s64(x << FRAC_BITS, y); | |
55 | } | |
56 | ||
57 | /** | |
58 | * struct power_allocator_params - parameters for the power allocator governor | |
59 | * @err_integral: accumulated error in the PID controller. | |
60 | * @prev_err: error in the previous iteration of the PID controller. | |
61 | * Used to calculate the derivative term. | |
62 | * @trip_switch_on: first passive trip point of the thermal zone. The | |
63 | * governor switches on when this trip point is crossed. | |
64 | * @trip_max_desired_temperature: last passive trip point of the thermal | |
65 | * zone. The temperature we are | |
66 | * controlling for. | |
67 | */ | |
68 | struct power_allocator_params { | |
69 | s64 err_integral; | |
70 | s32 prev_err; | |
71 | int trip_switch_on; | |
72 | int trip_max_desired_temperature; | |
73 | }; | |
74 | ||
e055bb0f JM |
75 | /** |
76 | * estimate_sustainable_power() - Estimate the sustainable power of a thermal zone | |
77 | * @tz: thermal zone we are operating in | |
78 | * | |
79 | * For thermal zones that don't provide a sustainable_power in their | |
80 | * thermal_zone_params, estimate one. Calculate it using the minimum | |
81 | * power of all the cooling devices as that gives a valid value that | |
82 | * can give some degree of functionality. For optimal performance of | |
83 | * this governor, provide a sustainable_power in the thermal zone's | |
84 | * thermal_zone_params. | |
85 | */ | |
86 | static u32 estimate_sustainable_power(struct thermal_zone_device *tz) | |
87 | { | |
88 | u32 sustainable_power = 0; | |
89 | struct thermal_instance *instance; | |
90 | struct power_allocator_params *params = tz->governor_data; | |
91 | ||
92 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
93 | struct thermal_cooling_device *cdev = instance->cdev; | |
94 | u32 min_power; | |
95 | ||
96 | if (instance->trip != params->trip_max_desired_temperature) | |
97 | continue; | |
98 | ||
99 | if (power_actor_get_min_power(cdev, tz, &min_power)) | |
100 | continue; | |
101 | ||
102 | sustainable_power += min_power; | |
103 | } | |
104 | ||
105 | return sustainable_power; | |
106 | } | |
107 | ||
108 | /** | |
109 | * estimate_pid_constants() - Estimate the constants for the PID controller | |
110 | * @tz: thermal zone for which to estimate the constants | |
111 | * @sustainable_power: sustainable power for the thermal zone | |
112 | * @trip_switch_on: trip point number for the switch on temperature | |
113 | * @control_temp: target temperature for the power allocator governor | |
114 | * @force: whether to force the update of the constants | |
115 | * | |
116 | * This function is used to update the estimation of the PID | |
117 | * controller constants in struct thermal_zone_parameters. | |
118 | * Sustainable power is provided in case it was estimated. The | |
119 | * estimated sustainable_power should not be stored in the | |
120 | * thermal_zone_parameters so it has to be passed explicitly to this | |
121 | * function. | |
122 | * | |
123 | * If @force is not set, the values in the thermal zone's parameters | |
124 | * are preserved if they are not zero. If @force is set, the values | |
125 | * in thermal zone's parameters are overwritten. | |
126 | */ | |
127 | static void estimate_pid_constants(struct thermal_zone_device *tz, | |
128 | u32 sustainable_power, int trip_switch_on, | |
129 | int control_temp, bool force) | |
130 | { | |
131 | int ret; | |
132 | int switch_on_temp; | |
133 | u32 temperature_threshold; | |
134 | ||
135 | ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp); | |
136 | if (ret) | |
137 | switch_on_temp = 0; | |
138 | ||
139 | temperature_threshold = control_temp - switch_on_temp; | |
140 | ||
141 | if (!tz->tzp->k_po || force) | |
142 | tz->tzp->k_po = int_to_frac(sustainable_power) / | |
143 | temperature_threshold; | |
144 | ||
145 | if (!tz->tzp->k_pu || force) | |
146 | tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / | |
147 | temperature_threshold; | |
148 | ||
149 | if (!tz->tzp->k_i || force) | |
150 | tz->tzp->k_i = int_to_frac(10) / 1000; | |
151 | /* | |
152 | * The default for k_d and integral_cutoff is 0, so we can | |
153 | * leave them as they are. | |
154 | */ | |
155 | } | |
156 | ||
6b775e87 JM |
157 | /** |
158 | * pid_controller() - PID controller | |
159 | * @tz: thermal zone we are operating in | |
160 | * @current_temp: the current temperature in millicelsius | |
161 | * @control_temp: the target temperature in millicelsius | |
162 | * @max_allocatable_power: maximum allocatable power for this thermal zone | |
163 | * | |
164 | * This PID controller increases the available power budget so that the | |
165 | * temperature of the thermal zone gets as close as possible to | |
166 | * @control_temp and limits the power if it exceeds it. k_po is the | |
167 | * proportional term when we are overshooting, k_pu is the | |
168 | * proportional term when we are undershooting. integral_cutoff is a | |
169 | * threshold below which we stop accumulating the error. The | |
170 | * accumulated error is only valid if the requested power will make | |
171 | * the system warmer. If the system is mostly idle, there's no point | |
172 | * in accumulating positive error. | |
173 | * | |
174 | * Return: The power budget for the next period. | |
175 | */ | |
176 | static u32 pid_controller(struct thermal_zone_device *tz, | |
17e8351a SH |
177 | int current_temp, |
178 | int control_temp, | |
6b775e87 JM |
179 | u32 max_allocatable_power) |
180 | { | |
181 | s64 p, i, d, power_range; | |
182 | s32 err, max_power_frac; | |
e055bb0f | 183 | u32 sustainable_power; |
6b775e87 JM |
184 | struct power_allocator_params *params = tz->governor_data; |
185 | ||
186 | max_power_frac = int_to_frac(max_allocatable_power); | |
187 | ||
e055bb0f JM |
188 | if (tz->tzp->sustainable_power) { |
189 | sustainable_power = tz->tzp->sustainable_power; | |
190 | } else { | |
191 | sustainable_power = estimate_sustainable_power(tz); | |
192 | estimate_pid_constants(tz, sustainable_power, | |
193 | params->trip_switch_on, control_temp, | |
194 | true); | |
195 | } | |
196 | ||
17e8351a | 197 | err = control_temp - current_temp; |
6b775e87 JM |
198 | err = int_to_frac(err); |
199 | ||
200 | /* Calculate the proportional term */ | |
201 | p = mul_frac(err < 0 ? tz->tzp->k_po : tz->tzp->k_pu, err); | |
202 | ||
203 | /* | |
204 | * Calculate the integral term | |
205 | * | |
206 | * if the error is less than cut off allow integration (but | |
207 | * the integral is limited to max power) | |
208 | */ | |
209 | i = mul_frac(tz->tzp->k_i, params->err_integral); | |
210 | ||
211 | if (err < int_to_frac(tz->tzp->integral_cutoff)) { | |
212 | s64 i_next = i + mul_frac(tz->tzp->k_i, err); | |
213 | ||
214 | if (abs64(i_next) < max_power_frac) { | |
215 | i = i_next; | |
216 | params->err_integral += err; | |
217 | } | |
218 | } | |
219 | ||
220 | /* | |
221 | * Calculate the derivative term | |
222 | * | |
223 | * We do err - prev_err, so with a positive k_d, a decreasing | |
224 | * error (i.e. driving closer to the line) results in less | |
225 | * power being applied, slowing down the controller) | |
226 | */ | |
227 | d = mul_frac(tz->tzp->k_d, err - params->prev_err); | |
228 | d = div_frac(d, tz->passive_delay); | |
229 | params->prev_err = err; | |
230 | ||
231 | power_range = p + i + d; | |
232 | ||
233 | /* feed-forward the known sustainable dissipatable power */ | |
e055bb0f | 234 | power_range = sustainable_power + frac_to_int(power_range); |
6b775e87 | 235 | |
6828a471 JM |
236 | power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power); |
237 | ||
238 | trace_thermal_power_allocator_pid(tz, frac_to_int(err), | |
239 | frac_to_int(params->err_integral), | |
240 | frac_to_int(p), frac_to_int(i), | |
241 | frac_to_int(d), power_range); | |
242 | ||
243 | return power_range; | |
6b775e87 JM |
244 | } |
245 | ||
246 | /** | |
247 | * divvy_up_power() - divvy the allocated power between the actors | |
248 | * @req_power: each actor's requested power | |
249 | * @max_power: each actor's maximum available power | |
250 | * @num_actors: size of the @req_power, @max_power and @granted_power's array | |
251 | * @total_req_power: sum of @req_power | |
252 | * @power_range: total allocated power | |
253 | * @granted_power: output array: each actor's granted power | |
254 | * @extra_actor_power: an appropriately sized array to be used in the | |
255 | * function as temporary storage of the extra power given | |
256 | * to the actors | |
257 | * | |
258 | * This function divides the total allocated power (@power_range) | |
259 | * fairly between the actors. It first tries to give each actor a | |
260 | * share of the @power_range according to how much power it requested | |
261 | * compared to the rest of the actors. For example, if only one actor | |
262 | * requests power, then it receives all the @power_range. If | |
263 | * three actors each requests 1mW, each receives a third of the | |
264 | * @power_range. | |
265 | * | |
266 | * If any actor received more than their maximum power, then that | |
267 | * surplus is re-divvied among the actors based on how far they are | |
268 | * from their respective maximums. | |
269 | * | |
270 | * Granted power for each actor is written to @granted_power, which | |
271 | * should've been allocated by the calling function. | |
272 | */ | |
273 | static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors, | |
274 | u32 total_req_power, u32 power_range, | |
275 | u32 *granted_power, u32 *extra_actor_power) | |
276 | { | |
277 | u32 extra_power, capped_extra_power; | |
278 | int i; | |
279 | ||
280 | /* | |
281 | * Prevent division by 0 if none of the actors request power. | |
282 | */ | |
283 | if (!total_req_power) | |
284 | total_req_power = 1; | |
285 | ||
286 | capped_extra_power = 0; | |
287 | extra_power = 0; | |
288 | for (i = 0; i < num_actors; i++) { | |
289 | u64 req_range = req_power[i] * power_range; | |
290 | ||
ea54cac9 JM |
291 | granted_power[i] = DIV_ROUND_CLOSEST_ULL(req_range, |
292 | total_req_power); | |
6b775e87 JM |
293 | |
294 | if (granted_power[i] > max_power[i]) { | |
295 | extra_power += granted_power[i] - max_power[i]; | |
296 | granted_power[i] = max_power[i]; | |
297 | } | |
298 | ||
299 | extra_actor_power[i] = max_power[i] - granted_power[i]; | |
300 | capped_extra_power += extra_actor_power[i]; | |
301 | } | |
302 | ||
303 | if (!extra_power) | |
304 | return; | |
305 | ||
306 | /* | |
307 | * Re-divvy the reclaimed extra among actors based on | |
308 | * how far they are from the max | |
309 | */ | |
310 | extra_power = min(extra_power, capped_extra_power); | |
311 | if (capped_extra_power > 0) | |
312 | for (i = 0; i < num_actors; i++) | |
313 | granted_power[i] += (extra_actor_power[i] * | |
314 | extra_power) / capped_extra_power; | |
315 | } | |
316 | ||
317 | static int allocate_power(struct thermal_zone_device *tz, | |
17e8351a SH |
318 | int current_temp, |
319 | int control_temp) | |
6b775e87 JM |
320 | { |
321 | struct thermal_instance *instance; | |
322 | struct power_allocator_params *params = tz->governor_data; | |
323 | u32 *req_power, *max_power, *granted_power, *extra_actor_power; | |
d5f83109 JM |
324 | u32 *weighted_req_power; |
325 | u32 total_req_power, max_allocatable_power, total_weighted_req_power; | |
6828a471 | 326 | u32 total_granted_power, power_range; |
6b775e87 JM |
327 | int i, num_actors, total_weight, ret = 0; |
328 | int trip_max_desired_temperature = params->trip_max_desired_temperature; | |
329 | ||
330 | mutex_lock(&tz->lock); | |
331 | ||
332 | num_actors = 0; | |
333 | total_weight = 0; | |
334 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
335 | if ((instance->trip == trip_max_desired_temperature) && | |
336 | cdev_is_power_actor(instance->cdev)) { | |
337 | num_actors++; | |
338 | total_weight += instance->weight; | |
339 | } | |
340 | } | |
341 | ||
342 | /* | |
d5f83109 JM |
343 | * We need to allocate five arrays of the same size: |
344 | * req_power, max_power, granted_power, extra_actor_power and | |
345 | * weighted_req_power. They are going to be needed until this | |
346 | * function returns. Allocate them all in one go to simplify | |
347 | * the allocation and deallocation logic. | |
6b775e87 JM |
348 | */ |
349 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*max_power)); | |
350 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*granted_power)); | |
351 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*extra_actor_power)); | |
d5f83109 | 352 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*weighted_req_power)); |
9751a9e4 | 353 | req_power = kcalloc(num_actors * 5, sizeof(*req_power), GFP_KERNEL); |
6b775e87 JM |
354 | if (!req_power) { |
355 | ret = -ENOMEM; | |
356 | goto unlock; | |
357 | } | |
358 | ||
359 | max_power = &req_power[num_actors]; | |
360 | granted_power = &req_power[2 * num_actors]; | |
361 | extra_actor_power = &req_power[3 * num_actors]; | |
d5f83109 | 362 | weighted_req_power = &req_power[4 * num_actors]; |
6b775e87 JM |
363 | |
364 | i = 0; | |
d5f83109 | 365 | total_weighted_req_power = 0; |
6b775e87 JM |
366 | total_req_power = 0; |
367 | max_allocatable_power = 0; | |
368 | ||
369 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
370 | int weight; | |
371 | struct thermal_cooling_device *cdev = instance->cdev; | |
372 | ||
373 | if (instance->trip != trip_max_desired_temperature) | |
374 | continue; | |
375 | ||
376 | if (!cdev_is_power_actor(cdev)) | |
377 | continue; | |
378 | ||
379 | if (cdev->ops->get_requested_power(cdev, tz, &req_power[i])) | |
380 | continue; | |
381 | ||
382 | if (!total_weight) | |
383 | weight = 1 << FRAC_BITS; | |
384 | else | |
385 | weight = instance->weight; | |
386 | ||
d5f83109 | 387 | weighted_req_power[i] = frac_to_int(weight * req_power[i]); |
6b775e87 JM |
388 | |
389 | if (power_actor_get_max_power(cdev, tz, &max_power[i])) | |
390 | continue; | |
391 | ||
392 | total_req_power += req_power[i]; | |
393 | max_allocatable_power += max_power[i]; | |
d5f83109 | 394 | total_weighted_req_power += weighted_req_power[i]; |
6b775e87 JM |
395 | |
396 | i++; | |
397 | } | |
398 | ||
399 | power_range = pid_controller(tz, current_temp, control_temp, | |
400 | max_allocatable_power); | |
401 | ||
d5f83109 JM |
402 | divvy_up_power(weighted_req_power, max_power, num_actors, |
403 | total_weighted_req_power, power_range, granted_power, | |
404 | extra_actor_power); | |
6b775e87 | 405 | |
6828a471 | 406 | total_granted_power = 0; |
6b775e87 JM |
407 | i = 0; |
408 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
409 | if (instance->trip != trip_max_desired_temperature) | |
410 | continue; | |
411 | ||
412 | if (!cdev_is_power_actor(instance->cdev)) | |
413 | continue; | |
414 | ||
415 | power_actor_set_power(instance->cdev, instance, | |
416 | granted_power[i]); | |
6828a471 | 417 | total_granted_power += granted_power[i]; |
6b775e87 JM |
418 | |
419 | i++; | |
420 | } | |
421 | ||
6828a471 JM |
422 | trace_thermal_power_allocator(tz, req_power, total_req_power, |
423 | granted_power, total_granted_power, | |
424 | num_actors, power_range, | |
425 | max_allocatable_power, current_temp, | |
17e8351a | 426 | control_temp - current_temp); |
6828a471 | 427 | |
cf736ea6 | 428 | kfree(req_power); |
6b775e87 JM |
429 | unlock: |
430 | mutex_unlock(&tz->lock); | |
431 | ||
432 | return ret; | |
433 | } | |
434 | ||
435 | static int get_governor_trips(struct thermal_zone_device *tz, | |
436 | struct power_allocator_params *params) | |
437 | { | |
438 | int i, ret, last_passive; | |
439 | bool found_first_passive; | |
440 | ||
441 | found_first_passive = false; | |
442 | last_passive = -1; | |
443 | ret = -EINVAL; | |
444 | ||
445 | for (i = 0; i < tz->trips; i++) { | |
446 | enum thermal_trip_type type; | |
447 | ||
448 | ret = tz->ops->get_trip_type(tz, i, &type); | |
449 | if (ret) | |
450 | return ret; | |
451 | ||
452 | if (!found_first_passive) { | |
453 | if (type == THERMAL_TRIP_PASSIVE) { | |
454 | params->trip_switch_on = i; | |
455 | found_first_passive = true; | |
456 | } | |
457 | } else if (type == THERMAL_TRIP_PASSIVE) { | |
458 | last_passive = i; | |
459 | } else { | |
460 | break; | |
461 | } | |
462 | } | |
463 | ||
464 | if (last_passive != -1) { | |
465 | params->trip_max_desired_temperature = last_passive; | |
466 | ret = 0; | |
467 | } else { | |
468 | ret = -EINVAL; | |
469 | } | |
470 | ||
471 | return ret; | |
472 | } | |
473 | ||
474 | static void reset_pid_controller(struct power_allocator_params *params) | |
475 | { | |
476 | params->err_integral = 0; | |
477 | params->prev_err = 0; | |
478 | } | |
479 | ||
480 | static void allow_maximum_power(struct thermal_zone_device *tz) | |
481 | { | |
482 | struct thermal_instance *instance; | |
483 | struct power_allocator_params *params = tz->governor_data; | |
484 | ||
485 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
486 | if ((instance->trip != params->trip_max_desired_temperature) || | |
487 | (!cdev_is_power_actor(instance->cdev))) | |
488 | continue; | |
489 | ||
490 | instance->target = 0; | |
491 | instance->cdev->updated = false; | |
492 | thermal_cdev_update(instance->cdev); | |
493 | } | |
494 | } | |
495 | ||
496 | /** | |
497 | * power_allocator_bind() - bind the power_allocator governor to a thermal zone | |
498 | * @tz: thermal zone to bind it to | |
499 | * | |
500 | * Check that the thermal zone is valid for this governor, that is, it | |
501 | * has two thermal trips. If so, initialize the PID controller | |
502 | * parameters and bind it to the thermal zone. | |
503 | * | |
504 | * Return: 0 on success, -EINVAL if the trips were invalid or -ENOMEM | |
505 | * if we ran out of memory. | |
506 | */ | |
507 | static int power_allocator_bind(struct thermal_zone_device *tz) | |
508 | { | |
509 | int ret; | |
510 | struct power_allocator_params *params; | |
e055bb0f | 511 | int control_temp; |
6b775e87 | 512 | |
e055bb0f | 513 | if (!tz->tzp) |
6b775e87 | 514 | return -EINVAL; |
6b775e87 | 515 | |
cf736ea6 | 516 | params = kzalloc(sizeof(*params), GFP_KERNEL); |
6b775e87 JM |
517 | if (!params) |
518 | return -ENOMEM; | |
519 | ||
e055bb0f JM |
520 | if (!tz->tzp->sustainable_power) |
521 | dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); | |
522 | ||
6b775e87 JM |
523 | ret = get_governor_trips(tz, params); |
524 | if (ret) { | |
525 | dev_err(&tz->device, | |
526 | "thermal zone %s has wrong trip setup for power allocator\n", | |
527 | tz->type); | |
528 | goto free; | |
529 | } | |
530 | ||
6b775e87 JM |
531 | ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature, |
532 | &control_temp); | |
533 | if (ret) | |
534 | goto free; | |
535 | ||
e055bb0f JM |
536 | estimate_pid_constants(tz, tz->tzp->sustainable_power, |
537 | params->trip_switch_on, control_temp, false); | |
6b775e87 JM |
538 | reset_pid_controller(params); |
539 | ||
540 | tz->governor_data = params; | |
541 | ||
542 | return 0; | |
543 | ||
544 | free: | |
cf736ea6 | 545 | kfree(params); |
6b775e87 JM |
546 | return ret; |
547 | } | |
548 | ||
549 | static void power_allocator_unbind(struct thermal_zone_device *tz) | |
550 | { | |
551 | dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id); | |
cf736ea6 | 552 | kfree(tz->governor_data); |
6b775e87 JM |
553 | tz->governor_data = NULL; |
554 | } | |
555 | ||
556 | static int power_allocator_throttle(struct thermal_zone_device *tz, int trip) | |
557 | { | |
558 | int ret; | |
17e8351a | 559 | int switch_on_temp, control_temp, current_temp; |
6b775e87 JM |
560 | struct power_allocator_params *params = tz->governor_data; |
561 | ||
562 | /* | |
563 | * We get called for every trip point but we only need to do | |
564 | * our calculations once | |
565 | */ | |
566 | if (trip != params->trip_max_desired_temperature) | |
567 | return 0; | |
568 | ||
569 | ret = thermal_zone_get_temp(tz, ¤t_temp); | |
570 | if (ret) { | |
571 | dev_warn(&tz->device, "Failed to get temperature: %d\n", ret); | |
572 | return ret; | |
573 | } | |
574 | ||
575 | ret = tz->ops->get_trip_temp(tz, params->trip_switch_on, | |
576 | &switch_on_temp); | |
577 | if (ret) { | |
578 | dev_warn(&tz->device, | |
579 | "Failed to get switch on temperature: %d\n", ret); | |
580 | return ret; | |
581 | } | |
582 | ||
583 | if (current_temp < switch_on_temp) { | |
584 | tz->passive = 0; | |
585 | reset_pid_controller(params); | |
586 | allow_maximum_power(tz); | |
587 | return 0; | |
588 | } | |
589 | ||
590 | tz->passive = 1; | |
591 | ||
592 | ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature, | |
593 | &control_temp); | |
594 | if (ret) { | |
595 | dev_warn(&tz->device, | |
596 | "Failed to get the maximum desired temperature: %d\n", | |
597 | ret); | |
598 | return ret; | |
599 | } | |
600 | ||
601 | return allocate_power(tz, current_temp, control_temp); | |
602 | } | |
603 | ||
604 | static struct thermal_governor thermal_gov_power_allocator = { | |
605 | .name = "power_allocator", | |
606 | .bind_to_tz = power_allocator_bind, | |
607 | .unbind_from_tz = power_allocator_unbind, | |
608 | .throttle = power_allocator_throttle, | |
609 | }; | |
610 | ||
611 | int thermal_gov_power_allocator_register(void) | |
612 | { | |
613 | return thermal_register_governor(&thermal_gov_power_allocator); | |
614 | } | |
615 | ||
616 | void thermal_gov_power_allocator_unregister(void) | |
617 | { | |
618 | thermal_unregister_governor(&thermal_gov_power_allocator); | |
619 | } |