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0de967f2 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6b775e87 JM |
2 | /* |
3 | * A power allocator to manage temperature | |
4 | * | |
5 | * Copyright (C) 2014 ARM Ltd. | |
6 | * | |
6b775e87 JM |
7 | */ |
8 | ||
9 | #define pr_fmt(fmt) "Power allocator: " fmt | |
10 | ||
11 | #include <linux/rculist.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/thermal.h> | |
14 | ||
6828a471 JM |
15 | #define CREATE_TRACE_POINTS |
16 | #include <trace/events/thermal_power_allocator.h> | |
17 | ||
6b775e87 JM |
18 | #include "thermal_core.h" |
19 | ||
8b7b390f JM |
20 | #define INVALID_TRIP -1 |
21 | ||
6b775e87 JM |
22 | #define FRAC_BITS 10 |
23 | #define int_to_frac(x) ((x) << FRAC_BITS) | |
24 | #define frac_to_int(x) ((x) >> FRAC_BITS) | |
25 | ||
26 | /** | |
27 | * mul_frac() - multiply two fixed-point numbers | |
28 | * @x: first multiplicand | |
29 | * @y: second multiplicand | |
30 | * | |
31 | * Return: the result of multiplying two fixed-point numbers. The | |
32 | * result is also a fixed-point number. | |
33 | */ | |
34 | static inline s64 mul_frac(s64 x, s64 y) | |
35 | { | |
36 | return (x * y) >> FRAC_BITS; | |
37 | } | |
38 | ||
39 | /** | |
40 | * div_frac() - divide two fixed-point numbers | |
41 | * @x: the dividend | |
42 | * @y: the divisor | |
43 | * | |
44 | * Return: the result of dividing two fixed-point numbers. The | |
45 | * result is also a fixed-point number. | |
46 | */ | |
47 | static inline s64 div_frac(s64 x, s64 y) | |
48 | { | |
49 | return div_s64(x << FRAC_BITS, y); | |
50 | } | |
51 | ||
52 | /** | |
53 | * struct power_allocator_params - parameters for the power allocator governor | |
f5cbb182 JM |
54 | * @allocated_tzp: whether we have allocated tzp for this thermal zone and |
55 | * it needs to be freed on unbind | |
6b775e87 JM |
56 | * @err_integral: accumulated error in the PID controller. |
57 | * @prev_err: error in the previous iteration of the PID controller. | |
58 | * Used to calculate the derivative term. | |
59 | * @trip_switch_on: first passive trip point of the thermal zone. The | |
60 | * governor switches on when this trip point is crossed. | |
8b7b390f JM |
61 | * If the thermal zone only has one passive trip point, |
62 | * @trip_switch_on should be INVALID_TRIP. | |
6b775e87 JM |
63 | * @trip_max_desired_temperature: last passive trip point of the thermal |
64 | * zone. The temperature we are | |
65 | * controlling for. | |
66 | */ | |
67 | struct power_allocator_params { | |
f5cbb182 | 68 | bool allocated_tzp; |
6b775e87 JM |
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 | ||
ecd1d2a3 | 99 | if (power_actor_get_min_power(cdev, &min_power)) |
e055bb0f JM |
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; | |
44241628 AA |
140 | /* |
141 | * estimate_pid_constants() tries to find appropriate default | |
142 | * values for thermal zones that don't provide them. If a | |
143 | * system integrator has configured a thermal zone with two | |
144 | * passive trip points at the same temperature, that person | |
145 | * hasn't put any effort to set up the thermal zone properly | |
146 | * so just give up. | |
147 | */ | |
148 | if (!temperature_threshold) | |
149 | return; | |
e055bb0f JM |
150 | |
151 | if (!tz->tzp->k_po || force) | |
152 | tz->tzp->k_po = int_to_frac(sustainable_power) / | |
153 | temperature_threshold; | |
154 | ||
155 | if (!tz->tzp->k_pu || force) | |
156 | tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / | |
157 | temperature_threshold; | |
158 | ||
159 | if (!tz->tzp->k_i || force) | |
160 | tz->tzp->k_i = int_to_frac(10) / 1000; | |
161 | /* | |
162 | * The default for k_d and integral_cutoff is 0, so we can | |
163 | * leave them as they are. | |
164 | */ | |
165 | } | |
166 | ||
6b775e87 JM |
167 | /** |
168 | * pid_controller() - PID controller | |
169 | * @tz: thermal zone we are operating in | |
6b775e87 JM |
170 | * @control_temp: the target temperature in millicelsius |
171 | * @max_allocatable_power: maximum allocatable power for this thermal zone | |
172 | * | |
173 | * This PID controller increases the available power budget so that the | |
174 | * temperature of the thermal zone gets as close as possible to | |
175 | * @control_temp and limits the power if it exceeds it. k_po is the | |
176 | * proportional term when we are overshooting, k_pu is the | |
177 | * proportional term when we are undershooting. integral_cutoff is a | |
178 | * threshold below which we stop accumulating the error. The | |
179 | * accumulated error is only valid if the requested power will make | |
180 | * the system warmer. If the system is mostly idle, there's no point | |
181 | * in accumulating positive error. | |
182 | * | |
183 | * Return: The power budget for the next period. | |
184 | */ | |
185 | static u32 pid_controller(struct thermal_zone_device *tz, | |
17e8351a | 186 | int control_temp, |
6b775e87 JM |
187 | u32 max_allocatable_power) |
188 | { | |
189 | s64 p, i, d, power_range; | |
190 | s32 err, max_power_frac; | |
e055bb0f | 191 | u32 sustainable_power; |
6b775e87 JM |
192 | struct power_allocator_params *params = tz->governor_data; |
193 | ||
194 | max_power_frac = int_to_frac(max_allocatable_power); | |
195 | ||
e055bb0f JM |
196 | if (tz->tzp->sustainable_power) { |
197 | sustainable_power = tz->tzp->sustainable_power; | |
198 | } else { | |
199 | sustainable_power = estimate_sustainable_power(tz); | |
200 | estimate_pid_constants(tz, sustainable_power, | |
201 | params->trip_switch_on, control_temp, | |
202 | true); | |
203 | } | |
204 | ||
bb404db4 | 205 | err = control_temp - tz->temperature; |
6b775e87 JM |
206 | err = int_to_frac(err); |
207 | ||
208 | /* Calculate the proportional term */ | |
209 | p = mul_frac(err < 0 ? tz->tzp->k_po : tz->tzp->k_pu, err); | |
210 | ||
211 | /* | |
212 | * Calculate the integral term | |
213 | * | |
214 | * if the error is less than cut off allow integration (but | |
215 | * the integral is limited to max power) | |
216 | */ | |
217 | i = mul_frac(tz->tzp->k_i, params->err_integral); | |
218 | ||
219 | if (err < int_to_frac(tz->tzp->integral_cutoff)) { | |
220 | s64 i_next = i + mul_frac(tz->tzp->k_i, err); | |
221 | ||
79211c8e | 222 | if (abs(i_next) < max_power_frac) { |
6b775e87 JM |
223 | i = i_next; |
224 | params->err_integral += err; | |
225 | } | |
226 | } | |
227 | ||
228 | /* | |
229 | * Calculate the derivative term | |
230 | * | |
231 | * We do err - prev_err, so with a positive k_d, a decreasing | |
232 | * error (i.e. driving closer to the line) results in less | |
233 | * power being applied, slowing down the controller) | |
234 | */ | |
235 | d = mul_frac(tz->tzp->k_d, err - params->prev_err); | |
236 | d = div_frac(d, tz->passive_delay); | |
237 | params->prev_err = err; | |
238 | ||
239 | power_range = p + i + d; | |
240 | ||
241 | /* feed-forward the known sustainable dissipatable power */ | |
e055bb0f | 242 | power_range = sustainable_power + frac_to_int(power_range); |
6b775e87 | 243 | |
6828a471 JM |
244 | power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power); |
245 | ||
246 | trace_thermal_power_allocator_pid(tz, frac_to_int(err), | |
247 | frac_to_int(params->err_integral), | |
248 | frac_to_int(p), frac_to_int(i), | |
249 | frac_to_int(d), power_range); | |
250 | ||
251 | return power_range; | |
6b775e87 JM |
252 | } |
253 | ||
254 | /** | |
255 | * divvy_up_power() - divvy the allocated power between the actors | |
256 | * @req_power: each actor's requested power | |
257 | * @max_power: each actor's maximum available power | |
258 | * @num_actors: size of the @req_power, @max_power and @granted_power's array | |
259 | * @total_req_power: sum of @req_power | |
260 | * @power_range: total allocated power | |
261 | * @granted_power: output array: each actor's granted power | |
262 | * @extra_actor_power: an appropriately sized array to be used in the | |
263 | * function as temporary storage of the extra power given | |
264 | * to the actors | |
265 | * | |
266 | * This function divides the total allocated power (@power_range) | |
267 | * fairly between the actors. It first tries to give each actor a | |
268 | * share of the @power_range according to how much power it requested | |
269 | * compared to the rest of the actors. For example, if only one actor | |
270 | * requests power, then it receives all the @power_range. If | |
271 | * three actors each requests 1mW, each receives a third of the | |
272 | * @power_range. | |
273 | * | |
274 | * If any actor received more than their maximum power, then that | |
275 | * surplus is re-divvied among the actors based on how far they are | |
276 | * from their respective maximums. | |
277 | * | |
278 | * Granted power for each actor is written to @granted_power, which | |
279 | * should've been allocated by the calling function. | |
280 | */ | |
281 | static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors, | |
282 | u32 total_req_power, u32 power_range, | |
283 | u32 *granted_power, u32 *extra_actor_power) | |
284 | { | |
285 | u32 extra_power, capped_extra_power; | |
286 | int i; | |
287 | ||
288 | /* | |
289 | * Prevent division by 0 if none of the actors request power. | |
290 | */ | |
291 | if (!total_req_power) | |
292 | total_req_power = 1; | |
293 | ||
294 | capped_extra_power = 0; | |
295 | extra_power = 0; | |
296 | for (i = 0; i < num_actors; i++) { | |
f9d03814 | 297 | u64 req_range = (u64)req_power[i] * power_range; |
6b775e87 | 298 | |
ea54cac9 JM |
299 | granted_power[i] = DIV_ROUND_CLOSEST_ULL(req_range, |
300 | total_req_power); | |
6b775e87 JM |
301 | |
302 | if (granted_power[i] > max_power[i]) { | |
303 | extra_power += granted_power[i] - max_power[i]; | |
304 | granted_power[i] = max_power[i]; | |
305 | } | |
306 | ||
307 | extra_actor_power[i] = max_power[i] - granted_power[i]; | |
308 | capped_extra_power += extra_actor_power[i]; | |
309 | } | |
310 | ||
311 | if (!extra_power) | |
312 | return; | |
313 | ||
314 | /* | |
315 | * Re-divvy the reclaimed extra among actors based on | |
316 | * how far they are from the max | |
317 | */ | |
318 | extra_power = min(extra_power, capped_extra_power); | |
319 | if (capped_extra_power > 0) | |
320 | for (i = 0; i < num_actors; i++) | |
321 | granted_power[i] += (extra_actor_power[i] * | |
322 | extra_power) / capped_extra_power; | |
323 | } | |
324 | ||
325 | static int allocate_power(struct thermal_zone_device *tz, | |
17e8351a | 326 | int control_temp) |
6b775e87 JM |
327 | { |
328 | struct thermal_instance *instance; | |
329 | struct power_allocator_params *params = tz->governor_data; | |
330 | u32 *req_power, *max_power, *granted_power, *extra_actor_power; | |
d5f83109 JM |
331 | u32 *weighted_req_power; |
332 | u32 total_req_power, max_allocatable_power, total_weighted_req_power; | |
6828a471 | 333 | u32 total_granted_power, power_range; |
6b775e87 JM |
334 | int i, num_actors, total_weight, ret = 0; |
335 | int trip_max_desired_temperature = params->trip_max_desired_temperature; | |
336 | ||
337 | mutex_lock(&tz->lock); | |
338 | ||
339 | num_actors = 0; | |
340 | total_weight = 0; | |
341 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
342 | if ((instance->trip == trip_max_desired_temperature) && | |
343 | cdev_is_power_actor(instance->cdev)) { | |
344 | num_actors++; | |
345 | total_weight += instance->weight; | |
346 | } | |
347 | } | |
348 | ||
97584d18 JM |
349 | if (!num_actors) { |
350 | ret = -ENODEV; | |
351 | goto unlock; | |
352 | } | |
353 | ||
6b775e87 | 354 | /* |
d5f83109 JM |
355 | * We need to allocate five arrays of the same size: |
356 | * req_power, max_power, granted_power, extra_actor_power and | |
357 | * weighted_req_power. They are going to be needed until this | |
358 | * function returns. Allocate them all in one go to simplify | |
359 | * the allocation and deallocation logic. | |
6b775e87 JM |
360 | */ |
361 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*max_power)); | |
362 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*granted_power)); | |
363 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*extra_actor_power)); | |
d5f83109 | 364 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*weighted_req_power)); |
9751a9e4 | 365 | req_power = kcalloc(num_actors * 5, sizeof(*req_power), GFP_KERNEL); |
6b775e87 JM |
366 | if (!req_power) { |
367 | ret = -ENOMEM; | |
368 | goto unlock; | |
369 | } | |
370 | ||
371 | max_power = &req_power[num_actors]; | |
372 | granted_power = &req_power[2 * num_actors]; | |
373 | extra_actor_power = &req_power[3 * num_actors]; | |
d5f83109 | 374 | weighted_req_power = &req_power[4 * num_actors]; |
6b775e87 JM |
375 | |
376 | i = 0; | |
d5f83109 | 377 | total_weighted_req_power = 0; |
6b775e87 JM |
378 | total_req_power = 0; |
379 | max_allocatable_power = 0; | |
380 | ||
381 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
382 | int weight; | |
383 | struct thermal_cooling_device *cdev = instance->cdev; | |
384 | ||
385 | if (instance->trip != trip_max_desired_temperature) | |
386 | continue; | |
387 | ||
388 | if (!cdev_is_power_actor(cdev)) | |
389 | continue; | |
390 | ||
ecd1d2a3 | 391 | if (cdev->ops->get_requested_power(cdev, &req_power[i])) |
6b775e87 JM |
392 | continue; |
393 | ||
394 | if (!total_weight) | |
395 | weight = 1 << FRAC_BITS; | |
396 | else | |
397 | weight = instance->weight; | |
398 | ||
d5f83109 | 399 | weighted_req_power[i] = frac_to_int(weight * req_power[i]); |
6b775e87 | 400 | |
ecd1d2a3 | 401 | if (power_actor_get_max_power(cdev, &max_power[i])) |
6b775e87 JM |
402 | continue; |
403 | ||
404 | total_req_power += req_power[i]; | |
405 | max_allocatable_power += max_power[i]; | |
d5f83109 | 406 | total_weighted_req_power += weighted_req_power[i]; |
6b775e87 JM |
407 | |
408 | i++; | |
409 | } | |
410 | ||
bb404db4 | 411 | power_range = pid_controller(tz, control_temp, max_allocatable_power); |
6b775e87 | 412 | |
d5f83109 JM |
413 | divvy_up_power(weighted_req_power, max_power, num_actors, |
414 | total_weighted_req_power, power_range, granted_power, | |
415 | extra_actor_power); | |
6b775e87 | 416 | |
6828a471 | 417 | total_granted_power = 0; |
6b775e87 JM |
418 | i = 0; |
419 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
420 | if (instance->trip != trip_max_desired_temperature) | |
421 | continue; | |
422 | ||
423 | if (!cdev_is_power_actor(instance->cdev)) | |
424 | continue; | |
425 | ||
426 | power_actor_set_power(instance->cdev, instance, | |
427 | granted_power[i]); | |
6828a471 | 428 | total_granted_power += granted_power[i]; |
6b775e87 JM |
429 | |
430 | i++; | |
431 | } | |
432 | ||
6828a471 JM |
433 | trace_thermal_power_allocator(tz, req_power, total_req_power, |
434 | granted_power, total_granted_power, | |
435 | num_actors, power_range, | |
bb404db4 KS |
436 | max_allocatable_power, tz->temperature, |
437 | control_temp - tz->temperature); | |
6828a471 | 438 | |
cf736ea6 | 439 | kfree(req_power); |
6b775e87 JM |
440 | unlock: |
441 | mutex_unlock(&tz->lock); | |
442 | ||
443 | return ret; | |
444 | } | |
445 | ||
8b7b390f JM |
446 | /** |
447 | * get_governor_trips() - get the number of the two trip points that are key for this governor | |
448 | * @tz: thermal zone to operate on | |
449 | * @params: pointer to private data for this governor | |
450 | * | |
451 | * The power allocator governor works optimally with two trips points: | |
452 | * a "switch on" trip point and a "maximum desired temperature". These | |
453 | * are defined as the first and last passive trip points. | |
454 | * | |
455 | * If there is only one trip point, then that's considered to be the | |
456 | * "maximum desired temperature" trip point and the governor is always | |
457 | * on. If there are no passive or active trip points, then the | |
458 | * governor won't do anything. In fact, its throttle function | |
459 | * won't be called at all. | |
460 | */ | |
461 | static void get_governor_trips(struct thermal_zone_device *tz, | |
462 | struct power_allocator_params *params) | |
6b775e87 | 463 | { |
8b7b390f | 464 | int i, last_active, last_passive; |
6b775e87 JM |
465 | bool found_first_passive; |
466 | ||
467 | found_first_passive = false; | |
8b7b390f JM |
468 | last_active = INVALID_TRIP; |
469 | last_passive = INVALID_TRIP; | |
6b775e87 JM |
470 | |
471 | for (i = 0; i < tz->trips; i++) { | |
472 | enum thermal_trip_type type; | |
8b7b390f | 473 | int ret; |
6b775e87 JM |
474 | |
475 | ret = tz->ops->get_trip_type(tz, i, &type); | |
8b7b390f JM |
476 | if (ret) { |
477 | dev_warn(&tz->device, | |
478 | "Failed to get trip point %d type: %d\n", i, | |
479 | ret); | |
480 | continue; | |
481 | } | |
6b775e87 | 482 | |
8b7b390f JM |
483 | if (type == THERMAL_TRIP_PASSIVE) { |
484 | if (!found_first_passive) { | |
6b775e87 JM |
485 | params->trip_switch_on = i; |
486 | found_first_passive = true; | |
8b7b390f JM |
487 | } else { |
488 | last_passive = i; | |
6b775e87 | 489 | } |
8b7b390f JM |
490 | } else if (type == THERMAL_TRIP_ACTIVE) { |
491 | last_active = i; | |
6b775e87 JM |
492 | } else { |
493 | break; | |
494 | } | |
495 | } | |
496 | ||
8b7b390f | 497 | if (last_passive != INVALID_TRIP) { |
6b775e87 | 498 | params->trip_max_desired_temperature = last_passive; |
8b7b390f JM |
499 | } else if (found_first_passive) { |
500 | params->trip_max_desired_temperature = params->trip_switch_on; | |
501 | params->trip_switch_on = INVALID_TRIP; | |
6b775e87 | 502 | } else { |
8b7b390f JM |
503 | params->trip_switch_on = INVALID_TRIP; |
504 | params->trip_max_desired_temperature = last_active; | |
6b775e87 | 505 | } |
6b775e87 JM |
506 | } |
507 | ||
508 | static void reset_pid_controller(struct power_allocator_params *params) | |
509 | { | |
510 | params->err_integral = 0; | |
511 | params->prev_err = 0; | |
512 | } | |
513 | ||
514 | static void allow_maximum_power(struct thermal_zone_device *tz) | |
515 | { | |
516 | struct thermal_instance *instance; | |
517 | struct power_allocator_params *params = tz->governor_data; | |
518 | ||
a5de11d6 | 519 | mutex_lock(&tz->lock); |
6b775e87 JM |
520 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { |
521 | if ((instance->trip != params->trip_max_desired_temperature) || | |
522 | (!cdev_is_power_actor(instance->cdev))) | |
523 | continue; | |
524 | ||
525 | instance->target = 0; | |
d0b7306d | 526 | mutex_lock(&instance->cdev->lock); |
6b775e87 | 527 | instance->cdev->updated = false; |
d0b7306d | 528 | mutex_unlock(&instance->cdev->lock); |
6b775e87 JM |
529 | thermal_cdev_update(instance->cdev); |
530 | } | |
a5de11d6 | 531 | mutex_unlock(&tz->lock); |
6b775e87 JM |
532 | } |
533 | ||
534 | /** | |
535 | * power_allocator_bind() - bind the power_allocator governor to a thermal zone | |
536 | * @tz: thermal zone to bind it to | |
537 | * | |
8b7b390f JM |
538 | * Initialize the PID controller parameters and bind it to the thermal |
539 | * zone. | |
6b775e87 | 540 | * |
f5cbb182 | 541 | * Return: 0 on success, or -ENOMEM if we ran out of memory. |
6b775e87 JM |
542 | */ |
543 | static int power_allocator_bind(struct thermal_zone_device *tz) | |
544 | { | |
545 | int ret; | |
546 | struct power_allocator_params *params; | |
e055bb0f | 547 | int control_temp; |
6b775e87 | 548 | |
cf736ea6 | 549 | params = kzalloc(sizeof(*params), GFP_KERNEL); |
6b775e87 JM |
550 | if (!params) |
551 | return -ENOMEM; | |
552 | ||
f5cbb182 JM |
553 | if (!tz->tzp) { |
554 | tz->tzp = kzalloc(sizeof(*tz->tzp), GFP_KERNEL); | |
555 | if (!tz->tzp) { | |
556 | ret = -ENOMEM; | |
557 | goto free_params; | |
558 | } | |
559 | ||
560 | params->allocated_tzp = true; | |
561 | } | |
562 | ||
e055bb0f JM |
563 | if (!tz->tzp->sustainable_power) |
564 | dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); | |
565 | ||
8b7b390f | 566 | get_governor_trips(tz, params); |
6b775e87 | 567 | |
8b7b390f JM |
568 | if (tz->trips > 0) { |
569 | ret = tz->ops->get_trip_temp(tz, | |
570 | params->trip_max_desired_temperature, | |
571 | &control_temp); | |
572 | if (!ret) | |
573 | estimate_pid_constants(tz, tz->tzp->sustainable_power, | |
574 | params->trip_switch_on, | |
575 | control_temp, false); | |
576 | } | |
6b775e87 | 577 | |
6b775e87 JM |
578 | reset_pid_controller(params); |
579 | ||
580 | tz->governor_data = params; | |
581 | ||
582 | return 0; | |
f5cbb182 JM |
583 | |
584 | free_params: | |
585 | kfree(params); | |
586 | ||
587 | return ret; | |
6b775e87 JM |
588 | } |
589 | ||
590 | static void power_allocator_unbind(struct thermal_zone_device *tz) | |
591 | { | |
f5cbb182 JM |
592 | struct power_allocator_params *params = tz->governor_data; |
593 | ||
6b775e87 | 594 | dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id); |
f5cbb182 JM |
595 | |
596 | if (params->allocated_tzp) { | |
597 | kfree(tz->tzp); | |
598 | tz->tzp = NULL; | |
599 | } | |
600 | ||
cf736ea6 | 601 | kfree(tz->governor_data); |
6b775e87 JM |
602 | tz->governor_data = NULL; |
603 | } | |
604 | ||
605 | static int power_allocator_throttle(struct thermal_zone_device *tz, int trip) | |
606 | { | |
607 | int ret; | |
bb404db4 | 608 | int switch_on_temp, control_temp; |
6b775e87 JM |
609 | struct power_allocator_params *params = tz->governor_data; |
610 | ||
611 | /* | |
612 | * We get called for every trip point but we only need to do | |
613 | * our calculations once | |
614 | */ | |
615 | if (trip != params->trip_max_desired_temperature) | |
616 | return 0; | |
617 | ||
6b775e87 JM |
618 | ret = tz->ops->get_trip_temp(tz, params->trip_switch_on, |
619 | &switch_on_temp); | |
bb404db4 | 620 | if (!ret && (tz->temperature < switch_on_temp)) { |
6b775e87 JM |
621 | tz->passive = 0; |
622 | reset_pid_controller(params); | |
623 | allow_maximum_power(tz); | |
624 | return 0; | |
625 | } | |
626 | ||
627 | tz->passive = 1; | |
628 | ||
629 | ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature, | |
630 | &control_temp); | |
631 | if (ret) { | |
632 | dev_warn(&tz->device, | |
633 | "Failed to get the maximum desired temperature: %d\n", | |
634 | ret); | |
635 | return ret; | |
636 | } | |
637 | ||
bb404db4 | 638 | return allocate_power(tz, control_temp); |
6b775e87 JM |
639 | } |
640 | ||
641 | static struct thermal_governor thermal_gov_power_allocator = { | |
642 | .name = "power_allocator", | |
643 | .bind_to_tz = power_allocator_bind, | |
644 | .unbind_from_tz = power_allocator_unbind, | |
645 | .throttle = power_allocator_throttle, | |
646 | }; | |
57c5b2ec | 647 | THERMAL_GOVERNOR_DECLARE(thermal_gov_power_allocator); |