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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> | |
2f96c035 | 24 | #include <linux/idr.h> |
a76caf55 ØE |
25 | #include <linux/slab.h> |
26 | #include <linux/pm_opp.h> | |
27 | #include <linux/thermal.h> | |
28 | ||
9876b1a4 JM |
29 | #include <trace/events/thermal.h> |
30 | ||
2f96c035 | 31 | static DEFINE_IDA(devfreq_ida); |
a76caf55 ØE |
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 | ||
a76caf55 ØE |
60 | /** |
61 | * partition_enable_opps() - disable all opps above a given state | |
62 | * @dfc: Pointer to devfreq we are operating on | |
63 | * @cdev_state: cooling device state we're setting | |
64 | * | |
65 | * Go through the OPPs of the device, enabling all OPPs until | |
66 | * @cdev_state and disabling those frequencies above it. | |
67 | */ | |
68 | static int partition_enable_opps(struct devfreq_cooling_device *dfc, | |
69 | unsigned long cdev_state) | |
70 | { | |
71 | int i; | |
72 | struct device *dev = dfc->devfreq->dev.parent; | |
73 | ||
74 | for (i = 0; i < dfc->freq_table_size; i++) { | |
75 | struct dev_pm_opp *opp; | |
76 | int ret = 0; | |
77 | unsigned int freq = dfc->freq_table[i]; | |
78 | bool want_enable = i >= cdev_state ? true : false; | |
79 | ||
a76caf55 | 80 | opp = dev_pm_opp_find_freq_exact(dev, freq, !want_enable); |
a76caf55 ØE |
81 | |
82 | if (PTR_ERR(opp) == -ERANGE) | |
83 | continue; | |
84 | else if (IS_ERR(opp)) | |
85 | return PTR_ERR(opp); | |
86 | ||
8a31d9d9 VK |
87 | dev_pm_opp_put(opp); |
88 | ||
a76caf55 ØE |
89 | if (want_enable) |
90 | ret = dev_pm_opp_enable(dev, freq); | |
91 | else | |
92 | ret = dev_pm_opp_disable(dev, freq); | |
93 | ||
94 | if (ret) | |
95 | return ret; | |
96 | } | |
97 | ||
98 | return 0; | |
99 | } | |
100 | ||
101 | static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev, | |
102 | unsigned long *state) | |
103 | { | |
104 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
105 | ||
106 | *state = dfc->freq_table_size - 1; | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | static int devfreq_cooling_get_cur_state(struct thermal_cooling_device *cdev, | |
112 | unsigned long *state) | |
113 | { | |
114 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
115 | ||
116 | *state = dfc->cooling_state; | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
121 | static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev, | |
122 | unsigned long state) | |
123 | { | |
124 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
125 | struct devfreq *df = dfc->devfreq; | |
126 | struct device *dev = df->dev.parent; | |
127 | int ret; | |
128 | ||
129 | if (state == dfc->cooling_state) | |
130 | return 0; | |
131 | ||
132 | dev_dbg(dev, "Setting cooling state %lu\n", state); | |
133 | ||
134 | if (state >= dfc->freq_table_size) | |
135 | return -EINVAL; | |
136 | ||
137 | ret = partition_enable_opps(dfc, state); | |
138 | if (ret) | |
139 | return ret; | |
140 | ||
141 | dfc->cooling_state = state; | |
142 | ||
143 | return 0; | |
144 | } | |
145 | ||
146 | /** | |
147 | * freq_get_state() - get the cooling state corresponding to a frequency | |
148 | * @dfc: Pointer to devfreq cooling device | |
149 | * @freq: frequency in Hz | |
150 | * | |
151 | * Return: the cooling state associated with the @freq, or | |
152 | * THERMAL_CSTATE_INVALID if it wasn't found. | |
153 | */ | |
154 | static unsigned long | |
155 | freq_get_state(struct devfreq_cooling_device *dfc, unsigned long freq) | |
156 | { | |
157 | int i; | |
158 | ||
159 | for (i = 0; i < dfc->freq_table_size; i++) { | |
160 | if (dfc->freq_table[i] == freq) | |
161 | return i; | |
162 | } | |
163 | ||
164 | return THERMAL_CSTATE_INVALID; | |
165 | } | |
166 | ||
167 | /** | |
168 | * get_static_power() - calculate the static power | |
169 | * @dfc: Pointer to devfreq cooling device | |
170 | * @freq: Frequency in Hz | |
171 | * | |
172 | * Calculate the static power in milliwatts using the supplied | |
173 | * get_static_power(). The current voltage is calculated using the | |
174 | * OPP library. If no get_static_power() was supplied, assume the | |
175 | * static power is negligible. | |
176 | */ | |
177 | static unsigned long | |
178 | get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq) | |
179 | { | |
180 | struct devfreq *df = dfc->devfreq; | |
181 | struct device *dev = df->dev.parent; | |
182 | unsigned long voltage; | |
183 | struct dev_pm_opp *opp; | |
184 | ||
185 | if (!dfc->power_ops->get_static_power) | |
186 | return 0; | |
187 | ||
a76caf55 | 188 | opp = dev_pm_opp_find_freq_exact(dev, freq, true); |
a4e49c9b | 189 | if (PTR_ERR(opp) == -ERANGE) |
a76caf55 ØE |
190 | opp = dev_pm_opp_find_freq_exact(dev, freq, false); |
191 | ||
afd1f4e0 VK |
192 | if (IS_ERR(opp)) { |
193 | dev_err_ratelimited(dev, "Failed to find OPP for frequency %lu: %ld\n", | |
194 | freq, PTR_ERR(opp)); | |
195 | return 0; | |
196 | } | |
197 | ||
a76caf55 | 198 | voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */ |
8a31d9d9 | 199 | dev_pm_opp_put(opp); |
a76caf55 ØE |
200 | |
201 | if (voltage == 0) { | |
8327b830 | 202 | dev_err_ratelimited(dev, |
afd1f4e0 VK |
203 | "Failed to get voltage for frequency %lu\n", |
204 | freq); | |
a76caf55 ØE |
205 | return 0; |
206 | } | |
207 | ||
3aa53743 | 208 | return dfc->power_ops->get_static_power(df, voltage); |
a76caf55 ØE |
209 | } |
210 | ||
211 | /** | |
212 | * get_dynamic_power - calculate the dynamic power | |
213 | * @dfc: Pointer to devfreq cooling device | |
214 | * @freq: Frequency in Hz | |
215 | * @voltage: Voltage in millivolts | |
216 | * | |
217 | * Calculate the dynamic power in milliwatts consumed by the device at | |
218 | * frequency @freq and voltage @voltage. If the get_dynamic_power() | |
219 | * was supplied as part of the devfreq_cooling_power struct, then that | |
220 | * function is used. Otherwise, a simple power model (Pdyn = Coeff * | |
221 | * Voltage^2 * Frequency) is used. | |
222 | */ | |
223 | static unsigned long | |
224 | get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq, | |
225 | unsigned long voltage) | |
226 | { | |
61c8e8aa | 227 | u64 power; |
a76caf55 ØE |
228 | u32 freq_mhz; |
229 | struct devfreq_cooling_power *dfc_power = dfc->power_ops; | |
230 | ||
231 | if (dfc_power->get_dynamic_power) | |
3aa53743 JM |
232 | return dfc_power->get_dynamic_power(dfc->devfreq, freq, |
233 | voltage); | |
a76caf55 ØE |
234 | |
235 | freq_mhz = freq / 1000000; | |
236 | power = (u64)dfc_power->dyn_power_coeff * freq_mhz * voltage * voltage; | |
237 | do_div(power, 1000000000); | |
238 | ||
239 | return power; | |
240 | } | |
241 | ||
242 | static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev, | |
243 | struct thermal_zone_device *tz, | |
244 | u32 *power) | |
245 | { | |
246 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
247 | struct devfreq *df = dfc->devfreq; | |
248 | struct devfreq_dev_status *status = &df->last_status; | |
249 | unsigned long state; | |
250 | unsigned long freq = status->current_frequency; | |
251 | u32 dyn_power, static_power; | |
252 | ||
253 | /* Get dynamic power for state */ | |
254 | state = freq_get_state(dfc, freq); | |
255 | if (state == THERMAL_CSTATE_INVALID) | |
256 | return -EAGAIN; | |
257 | ||
258 | dyn_power = dfc->power_table[state]; | |
259 | ||
260 | /* Scale dynamic power for utilization */ | |
261 | dyn_power = (dyn_power * status->busy_time) / status->total_time; | |
262 | ||
263 | /* Get static power */ | |
264 | static_power = get_static_power(dfc, freq); | |
265 | ||
9876b1a4 JM |
266 | trace_thermal_power_devfreq_get_power(cdev, status, freq, dyn_power, |
267 | static_power); | |
268 | ||
a76caf55 ØE |
269 | *power = dyn_power + static_power; |
270 | ||
271 | return 0; | |
272 | } | |
273 | ||
274 | static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev, | |
275 | struct thermal_zone_device *tz, | |
276 | unsigned long state, | |
277 | u32 *power) | |
278 | { | |
279 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
280 | unsigned long freq; | |
281 | u32 static_power; | |
282 | ||
e3da1cbe | 283 | if (state >= dfc->freq_table_size) |
a76caf55 ØE |
284 | return -EINVAL; |
285 | ||
286 | freq = dfc->freq_table[state]; | |
287 | static_power = get_static_power(dfc, freq); | |
288 | ||
289 | *power = dfc->power_table[state] + static_power; | |
290 | return 0; | |
291 | } | |
292 | ||
293 | static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev, | |
294 | struct thermal_zone_device *tz, | |
295 | u32 power, unsigned long *state) | |
296 | { | |
297 | struct devfreq_cooling_device *dfc = cdev->devdata; | |
298 | struct devfreq *df = dfc->devfreq; | |
299 | struct devfreq_dev_status *status = &df->last_status; | |
300 | unsigned long freq = status->current_frequency; | |
301 | unsigned long busy_time; | |
302 | s32 dyn_power; | |
303 | u32 static_power; | |
304 | int i; | |
305 | ||
306 | static_power = get_static_power(dfc, freq); | |
307 | ||
308 | dyn_power = power - static_power; | |
309 | dyn_power = dyn_power > 0 ? dyn_power : 0; | |
310 | ||
311 | /* Scale dynamic power for utilization */ | |
312 | busy_time = status->busy_time ?: 1; | |
313 | dyn_power = (dyn_power * status->total_time) / busy_time; | |
314 | ||
315 | /* | |
316 | * Find the first cooling state that is within the power | |
317 | * budget for dynamic power. | |
318 | */ | |
319 | for (i = 0; i < dfc->freq_table_size - 1; i++) | |
320 | if (dyn_power >= dfc->power_table[i]) | |
321 | break; | |
322 | ||
323 | *state = i; | |
9876b1a4 | 324 | trace_thermal_power_devfreq_limit(cdev, freq, *state, power); |
a76caf55 ØE |
325 | return 0; |
326 | } | |
327 | ||
328 | static struct thermal_cooling_device_ops devfreq_cooling_ops = { | |
329 | .get_max_state = devfreq_cooling_get_max_state, | |
330 | .get_cur_state = devfreq_cooling_get_cur_state, | |
331 | .set_cur_state = devfreq_cooling_set_cur_state, | |
332 | }; | |
333 | ||
334 | /** | |
335 | * devfreq_cooling_gen_tables() - Generate power and freq tables. | |
336 | * @dfc: Pointer to devfreq cooling device. | |
337 | * | |
338 | * Generate power and frequency tables: the power table hold the | |
339 | * device's maximum power usage at each cooling state (OPP). The | |
340 | * static and dynamic power using the appropriate voltage and | |
341 | * frequency for the state, is acquired from the struct | |
342 | * devfreq_cooling_power, and summed to make the maximum power draw. | |
343 | * | |
344 | * The frequency table holds the frequencies in descending order. | |
345 | * That way its indexed by cooling device state. | |
346 | * | |
347 | * The tables are malloced, and pointers put in dfc. They must be | |
348 | * freed when unregistering the devfreq cooling device. | |
349 | * | |
350 | * Return: 0 on success, negative error code on failure. | |
351 | */ | |
352 | static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc) | |
353 | { | |
354 | struct devfreq *df = dfc->devfreq; | |
355 | struct device *dev = df->dev.parent; | |
356 | int ret, num_opps; | |
357 | unsigned long freq; | |
358 | u32 *power_table = NULL; | |
359 | u32 *freq_table; | |
360 | int i; | |
361 | ||
362 | num_opps = dev_pm_opp_get_opp_count(dev); | |
363 | ||
364 | if (dfc->power_ops) { | |
365 | power_table = kcalloc(num_opps, sizeof(*power_table), | |
366 | GFP_KERNEL); | |
367 | if (!power_table) | |
ce5ee161 | 368 | return -ENOMEM; |
a76caf55 ØE |
369 | } |
370 | ||
371 | freq_table = kcalloc(num_opps, sizeof(*freq_table), | |
372 | GFP_KERNEL); | |
373 | if (!freq_table) { | |
374 | ret = -ENOMEM; | |
375 | goto free_power_table; | |
376 | } | |
377 | ||
378 | for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) { | |
379 | unsigned long power_dyn, voltage; | |
380 | struct dev_pm_opp *opp; | |
381 | ||
a76caf55 ØE |
382 | opp = dev_pm_opp_find_freq_floor(dev, &freq); |
383 | if (IS_ERR(opp)) { | |
a76caf55 ØE |
384 | ret = PTR_ERR(opp); |
385 | goto free_tables; | |
386 | } | |
387 | ||
388 | voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */ | |
8a31d9d9 | 389 | dev_pm_opp_put(opp); |
a76caf55 ØE |
390 | |
391 | if (dfc->power_ops) { | |
392 | power_dyn = get_dynamic_power(dfc, freq, voltage); | |
393 | ||
394 | dev_dbg(dev, "Dynamic power table: %lu MHz @ %lu mV: %lu = %lu mW\n", | |
395 | freq / 1000000, voltage, power_dyn, power_dyn); | |
396 | ||
397 | power_table[i] = power_dyn; | |
398 | } | |
399 | ||
400 | freq_table[i] = freq; | |
401 | } | |
402 | ||
403 | if (dfc->power_ops) | |
404 | dfc->power_table = power_table; | |
405 | ||
406 | dfc->freq_table = freq_table; | |
407 | dfc->freq_table_size = num_opps; | |
408 | ||
409 | return 0; | |
410 | ||
411 | free_tables: | |
412 | kfree(freq_table); | |
413 | free_power_table: | |
414 | kfree(power_table); | |
415 | ||
416 | return ret; | |
417 | } | |
418 | ||
419 | /** | |
420 | * of_devfreq_cooling_register_power() - Register devfreq cooling device, | |
421 | * with OF and power information. | |
422 | * @np: Pointer to OF device_node. | |
423 | * @df: Pointer to devfreq device. | |
424 | * @dfc_power: Pointer to devfreq_cooling_power. | |
425 | * | |
426 | * Register a devfreq cooling device. The available OPPs must be | |
427 | * registered on the device. | |
428 | * | |
429 | * If @dfc_power is provided, the cooling device is registered with the | |
430 | * power extensions. For the power extensions to work correctly, | |
431 | * devfreq should use the simple_ondemand governor, other governors | |
432 | * are not currently supported. | |
433 | */ | |
3c99c2ce | 434 | struct thermal_cooling_device * |
a76caf55 ØE |
435 | of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df, |
436 | struct devfreq_cooling_power *dfc_power) | |
437 | { | |
438 | struct thermal_cooling_device *cdev; | |
439 | struct devfreq_cooling_device *dfc; | |
440 | char dev_name[THERMAL_NAME_LENGTH]; | |
441 | int err; | |
442 | ||
443 | dfc = kzalloc(sizeof(*dfc), GFP_KERNEL); | |
444 | if (!dfc) | |
445 | return ERR_PTR(-ENOMEM); | |
446 | ||
447 | dfc->devfreq = df; | |
448 | ||
449 | if (dfc_power) { | |
450 | dfc->power_ops = dfc_power; | |
451 | ||
452 | devfreq_cooling_ops.get_requested_power = | |
453 | devfreq_cooling_get_requested_power; | |
454 | devfreq_cooling_ops.state2power = devfreq_cooling_state2power; | |
455 | devfreq_cooling_ops.power2state = devfreq_cooling_power2state; | |
456 | } | |
457 | ||
458 | err = devfreq_cooling_gen_tables(dfc); | |
459 | if (err) | |
460 | goto free_dfc; | |
461 | ||
2f96c035 MW |
462 | err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL); |
463 | if (err < 0) | |
a76caf55 | 464 | goto free_tables; |
2f96c035 | 465 | dfc->id = err; |
a76caf55 ØE |
466 | |
467 | snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id); | |
468 | ||
469 | cdev = thermal_of_cooling_device_register(np, dev_name, dfc, | |
470 | &devfreq_cooling_ops); | |
471 | if (IS_ERR(cdev)) { | |
472 | err = PTR_ERR(cdev); | |
473 | dev_err(df->dev.parent, | |
474 | "Failed to register devfreq cooling device (%d)\n", | |
475 | err); | |
2f96c035 | 476 | goto release_ida; |
a76caf55 ØE |
477 | } |
478 | ||
479 | dfc->cdev = cdev; | |
480 | ||
3c99c2ce | 481 | return cdev; |
a76caf55 | 482 | |
2f96c035 MW |
483 | release_ida: |
484 | ida_simple_remove(&devfreq_ida, dfc->id); | |
a76caf55 ØE |
485 | free_tables: |
486 | kfree(dfc->power_table); | |
487 | kfree(dfc->freq_table); | |
488 | free_dfc: | |
489 | kfree(dfc); | |
490 | ||
491 | return ERR_PTR(err); | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(of_devfreq_cooling_register_power); | |
494 | ||
495 | /** | |
496 | * of_devfreq_cooling_register() - Register devfreq cooling device, | |
497 | * with OF information. | |
498 | * @np: Pointer to OF device_node. | |
499 | * @df: Pointer to devfreq device. | |
500 | */ | |
3c99c2ce | 501 | struct thermal_cooling_device * |
a76caf55 ØE |
502 | of_devfreq_cooling_register(struct device_node *np, struct devfreq *df) |
503 | { | |
504 | return of_devfreq_cooling_register_power(np, df, NULL); | |
505 | } | |
506 | EXPORT_SYMBOL_GPL(of_devfreq_cooling_register); | |
507 | ||
508 | /** | |
509 | * devfreq_cooling_register() - Register devfreq cooling device. | |
510 | * @df: Pointer to devfreq device. | |
511 | */ | |
3c99c2ce | 512 | struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df) |
a76caf55 ØE |
513 | { |
514 | return of_devfreq_cooling_register(NULL, df); | |
515 | } | |
516 | EXPORT_SYMBOL_GPL(devfreq_cooling_register); | |
517 | ||
518 | /** | |
519 | * devfreq_cooling_unregister() - Unregister devfreq cooling device. | |
520 | * @dfc: Pointer to devfreq cooling device to unregister. | |
521 | */ | |
3c99c2ce | 522 | void devfreq_cooling_unregister(struct thermal_cooling_device *cdev) |
a76caf55 | 523 | { |
3c99c2ce JM |
524 | struct devfreq_cooling_device *dfc; |
525 | ||
526 | if (!cdev) | |
a76caf55 ØE |
527 | return; |
528 | ||
3c99c2ce JM |
529 | dfc = cdev->devdata; |
530 | ||
a76caf55 | 531 | thermal_cooling_device_unregister(dfc->cdev); |
2f96c035 | 532 | ida_simple_remove(&devfreq_ida, dfc->id); |
a76caf55 ØE |
533 | kfree(dfc->power_table); |
534 | kfree(dfc->freq_table); | |
535 | ||
536 | kfree(dfc); | |
537 | } | |
538 | EXPORT_SYMBOL_GPL(devfreq_cooling_unregister); |