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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * devfreq_cooling: Thermal cooling device implementation for devices using
4 * devfreq
5 *
6 * Copyright (C) 2014-2015 ARM Limited
7 *
8 * TODO:
9 * - If OPPs are added or removed after devfreq cooling has
10 * registered, the devfreq cooling won't react to it.
11 */
12
13#include <linux/devfreq.h>
14#include <linux/devfreq_cooling.h>
15#include <linux/export.h>
16#include <linux/idr.h>
17#include <linux/slab.h>
18#include <linux/pm_opp.h>
19#include <linux/pm_qos.h>
20#include <linux/thermal.h>
21
22#include <trace/events/thermal.h>
23
24#define HZ_PER_KHZ 1000
25#define SCALE_ERROR_MITIGATION 100
26
27static DEFINE_IDA(devfreq_ida);
28
29/**
30 * struct devfreq_cooling_device - Devfreq cooling device
31 * @id: unique integer value corresponding to each
32 * devfreq_cooling_device registered.
33 * @cdev: Pointer to associated thermal cooling device.
34 * @devfreq: Pointer to associated devfreq device.
35 * @cooling_state: Current cooling state.
36 * @power_table: Pointer to table with maximum power draw for each
37 * cooling state. State is the index into the table, and
38 * the power is in mW.
39 * @freq_table: Pointer to a table with the frequencies sorted in descending
40 * order. You can index the table by cooling device state
41 * @freq_table_size: Size of the @freq_table and @power_table
42 * @power_ops: Pointer to devfreq_cooling_power, used to generate the
43 * @power_table.
44 * @res_util: Resource utilization scaling factor for the power.
45 * It is multiplied by 100 to minimize the error. It is used
46 * for estimation of the power budget instead of using
47 * 'utilization' (which is 'busy_time / 'total_time').
48 * The 'res_util' range is from 100 to (power_table[state] * 100)
49 * for the corresponding 'state'.
50 * @capped_state: index to cooling state with in dynamic power budget
51 * @req_max_freq: PM QoS request for limiting the maximum frequency
52 * of the devfreq device.
53 */
54struct devfreq_cooling_device {
55 int id;
56 struct thermal_cooling_device *cdev;
57 struct devfreq *devfreq;
58 unsigned long cooling_state;
59 u32 *power_table;
60 u32 *freq_table;
61 size_t freq_table_size;
62 struct devfreq_cooling_power *power_ops;
63 u32 res_util;
64 int capped_state;
65 struct dev_pm_qos_request req_max_freq;
66};
67
68static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev,
69 unsigned long *state)
70{
71 struct devfreq_cooling_device *dfc = cdev->devdata;
72
73 *state = dfc->freq_table_size - 1;
74
75 return 0;
76}
77
78static int devfreq_cooling_get_cur_state(struct thermal_cooling_device *cdev,
79 unsigned long *state)
80{
81 struct devfreq_cooling_device *dfc = cdev->devdata;
82
83 *state = dfc->cooling_state;
84
85 return 0;
86}
87
88static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev,
89 unsigned long state)
90{
91 struct devfreq_cooling_device *dfc = cdev->devdata;
92 struct devfreq *df = dfc->devfreq;
93 struct device *dev = df->dev.parent;
94 unsigned long freq;
95
96 if (state == dfc->cooling_state)
97 return 0;
98
99 dev_dbg(dev, "Setting cooling state %lu\n", state);
100
101 if (state >= dfc->freq_table_size)
102 return -EINVAL;
103
104 freq = dfc->freq_table[state];
105
106 dev_pm_qos_update_request(&dfc->req_max_freq,
107 DIV_ROUND_UP(freq, HZ_PER_KHZ));
108
109 dfc->cooling_state = state;
110
111 return 0;
112}
113
114/**
115 * freq_get_state() - get the cooling state corresponding to a frequency
116 * @dfc: Pointer to devfreq cooling device
117 * @freq: frequency in Hz
118 *
119 * Return: the cooling state associated with the @freq, or
120 * THERMAL_CSTATE_INVALID if it wasn't found.
121 */
122static unsigned long
123freq_get_state(struct devfreq_cooling_device *dfc, unsigned long freq)
124{
125 int i;
126
127 for (i = 0; i < dfc->freq_table_size; i++) {
128 if (dfc->freq_table[i] == freq)
129 return i;
130 }
131
132 return THERMAL_CSTATE_INVALID;
133}
134
135static unsigned long get_voltage(struct devfreq *df, unsigned long freq)
136{
137 struct device *dev = df->dev.parent;
138 unsigned long voltage;
139 struct dev_pm_opp *opp;
140
141 opp = dev_pm_opp_find_freq_exact(dev, freq, true);
142 if (PTR_ERR(opp) == -ERANGE)
143 opp = dev_pm_opp_find_freq_exact(dev, freq, false);
144
145 if (IS_ERR(opp)) {
146 dev_err_ratelimited(dev, "Failed to find OPP for frequency %lu: %ld\n",
147 freq, PTR_ERR(opp));
148 return 0;
149 }
150
151 voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
152 dev_pm_opp_put(opp);
153
154 if (voltage == 0) {
155 dev_err_ratelimited(dev,
156 "Failed to get voltage for frequency %lu\n",
157 freq);
158 }
159
160 return voltage;
161}
162
163/**
164 * get_static_power() - calculate the static power
165 * @dfc: Pointer to devfreq cooling device
166 * @freq: Frequency in Hz
167 *
168 * Calculate the static power in milliwatts using the supplied
169 * get_static_power(). The current voltage is calculated using the
170 * OPP library. If no get_static_power() was supplied, assume the
171 * static power is negligible.
172 */
173static unsigned long
174get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq)
175{
176 struct devfreq *df = dfc->devfreq;
177 unsigned long voltage;
178
179 if (!dfc->power_ops->get_static_power)
180 return 0;
181
182 voltage = get_voltage(df, freq);
183
184 if (voltage == 0)
185 return 0;
186
187 return dfc->power_ops->get_static_power(df, voltage);
188}
189
190/**
191 * get_dynamic_power - calculate the dynamic power
192 * @dfc: Pointer to devfreq cooling device
193 * @freq: Frequency in Hz
194 * @voltage: Voltage in millivolts
195 *
196 * Calculate the dynamic power in milliwatts consumed by the device at
197 * frequency @freq and voltage @voltage. If the get_dynamic_power()
198 * was supplied as part of the devfreq_cooling_power struct, then that
199 * function is used. Otherwise, a simple power model (Pdyn = Coeff *
200 * Voltage^2 * Frequency) is used.
201 */
202static unsigned long
203get_dynamic_power(struct devfreq_cooling_device *dfc, unsigned long freq,
204 unsigned long voltage)
205{
206 u64 power;
207 u32 freq_mhz;
208 struct devfreq_cooling_power *dfc_power = dfc->power_ops;
209
210 if (dfc_power->get_dynamic_power)
211 return dfc_power->get_dynamic_power(dfc->devfreq, freq,
212 voltage);
213
214 freq_mhz = freq / 1000000;
215 power = (u64)dfc_power->dyn_power_coeff * freq_mhz * voltage * voltage;
216 do_div(power, 1000000000);
217
218 return power;
219}
220
221
222static inline unsigned long get_total_power(struct devfreq_cooling_device *dfc,
223 unsigned long freq,
224 unsigned long voltage)
225{
226 return get_static_power(dfc, freq) + get_dynamic_power(dfc, freq,
227 voltage);
228}
229
230
231static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev,
232 struct thermal_zone_device *tz,
233 u32 *power)
234{
235 struct devfreq_cooling_device *dfc = cdev->devdata;
236 struct devfreq *df = dfc->devfreq;
237 struct devfreq_dev_status *status = &df->last_status;
238 unsigned long state;
239 unsigned long freq = status->current_frequency;
240 unsigned long voltage;
241 u32 dyn_power = 0;
242 u32 static_power = 0;
243 int res;
244
245 state = freq_get_state(dfc, freq);
246 if (state == THERMAL_CSTATE_INVALID) {
247 res = -EAGAIN;
248 goto fail;
249 }
250
251 if (dfc->power_ops->get_real_power) {
252 voltage = get_voltage(df, freq);
253 if (voltage == 0) {
254 res = -EINVAL;
255 goto fail;
256 }
257
258 res = dfc->power_ops->get_real_power(df, power, freq, voltage);
259 if (!res) {
260 state = dfc->capped_state;
261 dfc->res_util = dfc->power_table[state];
262 dfc->res_util *= SCALE_ERROR_MITIGATION;
263
264 if (*power > 1)
265 dfc->res_util /= *power;
266 } else {
267 goto fail;
268 }
269 } else {
270 dyn_power = dfc->power_table[state];
271
272 /* Scale dynamic power for utilization */
273 dyn_power *= status->busy_time;
274 dyn_power /= status->total_time;
275 /* Get static power */
276 static_power = get_static_power(dfc, freq);
277
278 *power = dyn_power + static_power;
279 }
280
281 trace_thermal_power_devfreq_get_power(cdev, status, freq, dyn_power,
282 static_power, *power);
283
284 return 0;
285fail:
286 /* It is safe to set max in this case */
287 dfc->res_util = SCALE_ERROR_MITIGATION;
288 return res;
289}
290
291static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev,
292 struct thermal_zone_device *tz,
293 unsigned long state,
294 u32 *power)
295{
296 struct devfreq_cooling_device *dfc = cdev->devdata;
297 unsigned long freq;
298 u32 static_power;
299
300 if (state >= dfc->freq_table_size)
301 return -EINVAL;
302
303 freq = dfc->freq_table[state];
304 static_power = get_static_power(dfc, freq);
305
306 *power = dfc->power_table[state] + static_power;
307 return 0;
308}
309
310static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev,
311 struct thermal_zone_device *tz,
312 u32 power, unsigned long *state)
313{
314 struct devfreq_cooling_device *dfc = cdev->devdata;
315 struct devfreq *df = dfc->devfreq;
316 struct devfreq_dev_status *status = &df->last_status;
317 unsigned long freq = status->current_frequency;
318 unsigned long busy_time;
319 s32 dyn_power;
320 u32 static_power;
321 s32 est_power;
322 int i;
323
324 if (dfc->power_ops->get_real_power) {
325 /* Scale for resource utilization */
326 est_power = power * dfc->res_util;
327 est_power /= SCALE_ERROR_MITIGATION;
328 } else {
329 static_power = get_static_power(dfc, freq);
330
331 dyn_power = power - static_power;
332 dyn_power = dyn_power > 0 ? dyn_power : 0;
333
334 /* Scale dynamic power for utilization */
335 busy_time = status->busy_time ?: 1;
336 est_power = (dyn_power * status->total_time) / busy_time;
337 }
338
339 /*
340 * Find the first cooling state that is within the power
341 * budget for dynamic power.
342 */
343 for (i = 0; i < dfc->freq_table_size - 1; i++)
344 if (est_power >= dfc->power_table[i])
345 break;
346
347 *state = i;
348 dfc->capped_state = i;
349 trace_thermal_power_devfreq_limit(cdev, freq, *state, power);
350 return 0;
351}
352
353static struct thermal_cooling_device_ops devfreq_cooling_ops = {
354 .get_max_state = devfreq_cooling_get_max_state,
355 .get_cur_state = devfreq_cooling_get_cur_state,
356 .set_cur_state = devfreq_cooling_set_cur_state,
357};
358
359/**
360 * devfreq_cooling_gen_tables() - Generate power and freq tables.
361 * @dfc: Pointer to devfreq cooling device.
362 *
363 * Generate power and frequency tables: the power table hold the
364 * device's maximum power usage at each cooling state (OPP). The
365 * static and dynamic power using the appropriate voltage and
366 * frequency for the state, is acquired from the struct
367 * devfreq_cooling_power, and summed to make the maximum power draw.
368 *
369 * The frequency table holds the frequencies in descending order.
370 * That way its indexed by cooling device state.
371 *
372 * The tables are malloced, and pointers put in dfc. They must be
373 * freed when unregistering the devfreq cooling device.
374 *
375 * Return: 0 on success, negative error code on failure.
376 */
377static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc)
378{
379 struct devfreq *df = dfc->devfreq;
380 struct device *dev = df->dev.parent;
381 int ret, num_opps;
382 unsigned long freq;
383 u32 *power_table = NULL;
384 u32 *freq_table;
385 int i;
386
387 num_opps = dev_pm_opp_get_opp_count(dev);
388
389 if (dfc->power_ops) {
390 power_table = kcalloc(num_opps, sizeof(*power_table),
391 GFP_KERNEL);
392 if (!power_table)
393 return -ENOMEM;
394 }
395
396 freq_table = kcalloc(num_opps, sizeof(*freq_table),
397 GFP_KERNEL);
398 if (!freq_table) {
399 ret = -ENOMEM;
400 goto free_power_table;
401 }
402
403 for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) {
404 unsigned long power, voltage;
405 struct dev_pm_opp *opp;
406
407 opp = dev_pm_opp_find_freq_floor(dev, &freq);
408 if (IS_ERR(opp)) {
409 ret = PTR_ERR(opp);
410 goto free_tables;
411 }
412
413 voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
414 dev_pm_opp_put(opp);
415
416 if (dfc->power_ops) {
417 if (dfc->power_ops->get_real_power)
418 power = get_total_power(dfc, freq, voltage);
419 else
420 power = get_dynamic_power(dfc, freq, voltage);
421
422 dev_dbg(dev, "Power table: %lu MHz @ %lu mV: %lu = %lu mW\n",
423 freq / 1000000, voltage, power, power);
424
425 power_table[i] = power;
426 }
427
428 freq_table[i] = freq;
429 }
430
431 if (dfc->power_ops)
432 dfc->power_table = power_table;
433
434 dfc->freq_table = freq_table;
435 dfc->freq_table_size = num_opps;
436
437 return 0;
438
439free_tables:
440 kfree(freq_table);
441free_power_table:
442 kfree(power_table);
443
444 return ret;
445}
446
447/**
448 * of_devfreq_cooling_register_power() - Register devfreq cooling device,
449 * with OF and power information.
450 * @np: Pointer to OF device_node.
451 * @df: Pointer to devfreq device.
452 * @dfc_power: Pointer to devfreq_cooling_power.
453 *
454 * Register a devfreq cooling device. The available OPPs must be
455 * registered on the device.
456 *
457 * If @dfc_power is provided, the cooling device is registered with the
458 * power extensions. For the power extensions to work correctly,
459 * devfreq should use the simple_ondemand governor, other governors
460 * are not currently supported.
461 */
462struct thermal_cooling_device *
463of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
464 struct devfreq_cooling_power *dfc_power)
465{
466 struct thermal_cooling_device *cdev;
467 struct devfreq_cooling_device *dfc;
468 char dev_name[THERMAL_NAME_LENGTH];
469 int err;
470
471 dfc = kzalloc(sizeof(*dfc), GFP_KERNEL);
472 if (!dfc)
473 return ERR_PTR(-ENOMEM);
474
475 dfc->devfreq = df;
476
477 if (dfc_power) {
478 dfc->power_ops = dfc_power;
479
480 devfreq_cooling_ops.get_requested_power =
481 devfreq_cooling_get_requested_power;
482 devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
483 devfreq_cooling_ops.power2state = devfreq_cooling_power2state;
484 }
485
486 err = devfreq_cooling_gen_tables(dfc);
487 if (err)
488 goto free_dfc;
489
490 err = dev_pm_qos_add_request(df->dev.parent, &dfc->req_max_freq,
491 DEV_PM_QOS_MAX_FREQUENCY,
492 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
493 if (err < 0)
494 goto free_tables;
495
496 err = ida_simple_get(&devfreq_ida, 0, 0, GFP_KERNEL);
497 if (err < 0)
498 goto remove_qos_req;
499 dfc->id = err;
500
501 snprintf(dev_name, sizeof(dev_name), "thermal-devfreq-%d", dfc->id);
502
503 cdev = thermal_of_cooling_device_register(np, dev_name, dfc,
504 &devfreq_cooling_ops);
505 if (IS_ERR(cdev)) {
506 err = PTR_ERR(cdev);
507 dev_err(df->dev.parent,
508 "Failed to register devfreq cooling device (%d)\n",
509 err);
510 goto release_ida;
511 }
512
513 dfc->cdev = cdev;
514
515 return cdev;
516
517release_ida:
518 ida_simple_remove(&devfreq_ida, dfc->id);
519
520remove_qos_req:
521 dev_pm_qos_remove_request(&dfc->req_max_freq);
522
523free_tables:
524 kfree(dfc->power_table);
525 kfree(dfc->freq_table);
526free_dfc:
527 kfree(dfc);
528
529 return ERR_PTR(err);
530}
531EXPORT_SYMBOL_GPL(of_devfreq_cooling_register_power);
532
533/**
534 * of_devfreq_cooling_register() - Register devfreq cooling device,
535 * with OF information.
536 * @np: Pointer to OF device_node.
537 * @df: Pointer to devfreq device.
538 */
539struct thermal_cooling_device *
540of_devfreq_cooling_register(struct device_node *np, struct devfreq *df)
541{
542 return of_devfreq_cooling_register_power(np, df, NULL);
543}
544EXPORT_SYMBOL_GPL(of_devfreq_cooling_register);
545
546/**
547 * devfreq_cooling_register() - Register devfreq cooling device.
548 * @df: Pointer to devfreq device.
549 */
550struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df)
551{
552 return of_devfreq_cooling_register(NULL, df);
553}
554EXPORT_SYMBOL_GPL(devfreq_cooling_register);
555
556/**
557 * devfreq_cooling_unregister() - Unregister devfreq cooling device.
558 * @cdev: Pointer to devfreq cooling device to unregister.
559 */
560void devfreq_cooling_unregister(struct thermal_cooling_device *cdev)
561{
562 struct devfreq_cooling_device *dfc;
563
564 if (!cdev)
565 return;
566
567 dfc = cdev->devdata;
568
569 thermal_cooling_device_unregister(dfc->cdev);
570 ida_simple_remove(&devfreq_ida, dfc->id);
571 dev_pm_qos_remove_request(&dfc->req_max_freq);
572 kfree(dfc->power_table);
573 kfree(dfc->freq_table);
574
575 kfree(dfc);
576}
577EXPORT_SYMBOL_GPL(devfreq_cooling_unregister);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * devfreq_cooling: Thermal cooling device implementation for devices using
4 * devfreq
5 *
6 * Copyright (C) 2014-2015 ARM Limited
7 *
8 * TODO:
9 * - If OPPs are added or removed after devfreq cooling has
10 * registered, the devfreq cooling won't react to it.
11 */
12
13#include <linux/devfreq.h>
14#include <linux/devfreq_cooling.h>
15#include <linux/energy_model.h>
16#include <linux/export.h>
17#include <linux/slab.h>
18#include <linux/pm_opp.h>
19#include <linux/pm_qos.h>
20#include <linux/thermal.h>
21#include <linux/units.h>
22
23#include "thermal_trace.h"
24
25#define SCALE_ERROR_MITIGATION 100
26
27/**
28 * struct devfreq_cooling_device - Devfreq cooling device
29 * devfreq_cooling_device registered.
30 * @cdev: Pointer to associated thermal cooling device.
31 * @cooling_ops: devfreq callbacks to thermal cooling device ops
32 * @devfreq: Pointer to associated devfreq device.
33 * @cooling_state: Current cooling state.
34 * @freq_table: Pointer to a table with the frequencies sorted in descending
35 * order. You can index the table by cooling device state
36 * @max_state: It is the last index, that is, one less than the number of the
37 * OPPs
38 * @power_ops: Pointer to devfreq_cooling_power, a more precised model.
39 * @res_util: Resource utilization scaling factor for the power.
40 * It is multiplied by 100 to minimize the error. It is used
41 * for estimation of the power budget instead of using
42 * 'utilization' (which is 'busy_time' / 'total_time').
43 * The 'res_util' range is from 100 to power * 100 for the
44 * corresponding 'state'.
45 * @capped_state: index to cooling state with in dynamic power budget
46 * @req_max_freq: PM QoS request for limiting the maximum frequency
47 * of the devfreq device.
48 * @em_pd: Energy Model for the associated Devfreq device
49 */
50struct devfreq_cooling_device {
51 struct thermal_cooling_device *cdev;
52 struct thermal_cooling_device_ops cooling_ops;
53 struct devfreq *devfreq;
54 unsigned long cooling_state;
55 u32 *freq_table;
56 size_t max_state;
57 struct devfreq_cooling_power *power_ops;
58 u32 res_util;
59 int capped_state;
60 struct dev_pm_qos_request req_max_freq;
61 struct em_perf_domain *em_pd;
62};
63
64static int devfreq_cooling_get_max_state(struct thermal_cooling_device *cdev,
65 unsigned long *state)
66{
67 struct devfreq_cooling_device *dfc = cdev->devdata;
68
69 *state = dfc->max_state;
70
71 return 0;
72}
73
74static int devfreq_cooling_get_cur_state(struct thermal_cooling_device *cdev,
75 unsigned long *state)
76{
77 struct devfreq_cooling_device *dfc = cdev->devdata;
78
79 *state = dfc->cooling_state;
80
81 return 0;
82}
83
84static int devfreq_cooling_set_cur_state(struct thermal_cooling_device *cdev,
85 unsigned long state)
86{
87 struct devfreq_cooling_device *dfc = cdev->devdata;
88 struct devfreq *df = dfc->devfreq;
89 struct device *dev = df->dev.parent;
90 unsigned long freq;
91 int perf_idx;
92
93 if (state == dfc->cooling_state)
94 return 0;
95
96 dev_dbg(dev, "Setting cooling state %lu\n", state);
97
98 if (state > dfc->max_state)
99 return -EINVAL;
100
101 if (dfc->em_pd) {
102 perf_idx = dfc->max_state - state;
103 freq = dfc->em_pd->table[perf_idx].frequency * 1000;
104 } else {
105 freq = dfc->freq_table[state];
106 }
107
108 dev_pm_qos_update_request(&dfc->req_max_freq,
109 DIV_ROUND_UP(freq, HZ_PER_KHZ));
110
111 dfc->cooling_state = state;
112
113 return 0;
114}
115
116/**
117 * get_perf_idx() - get the performance index corresponding to a frequency
118 * @em_pd: Pointer to device's Energy Model
119 * @freq: frequency in kHz
120 *
121 * Return: the performance index associated with the @freq, or
122 * -EINVAL if it wasn't found.
123 */
124static int get_perf_idx(struct em_perf_domain *em_pd, unsigned long freq)
125{
126 int i;
127
128 for (i = 0; i < em_pd->nr_perf_states; i++) {
129 if (em_pd->table[i].frequency == freq)
130 return i;
131 }
132
133 return -EINVAL;
134}
135
136static unsigned long get_voltage(struct devfreq *df, unsigned long freq)
137{
138 struct device *dev = df->dev.parent;
139 unsigned long voltage;
140 struct dev_pm_opp *opp;
141
142 opp = dev_pm_opp_find_freq_exact(dev, freq, true);
143 if (PTR_ERR(opp) == -ERANGE)
144 opp = dev_pm_opp_find_freq_exact(dev, freq, false);
145
146 if (IS_ERR(opp)) {
147 dev_err_ratelimited(dev, "Failed to find OPP for frequency %lu: %ld\n",
148 freq, PTR_ERR(opp));
149 return 0;
150 }
151
152 voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
153 dev_pm_opp_put(opp);
154
155 if (voltage == 0) {
156 dev_err_ratelimited(dev,
157 "Failed to get voltage for frequency %lu\n",
158 freq);
159 }
160
161 return voltage;
162}
163
164static void _normalize_load(struct devfreq_dev_status *status)
165{
166 if (status->total_time > 0xfffff) {
167 status->total_time >>= 10;
168 status->busy_time >>= 10;
169 }
170
171 status->busy_time <<= 10;
172 status->busy_time /= status->total_time ? : 1;
173
174 status->busy_time = status->busy_time ? : 1;
175 status->total_time = 1024;
176}
177
178static int devfreq_cooling_get_requested_power(struct thermal_cooling_device *cdev,
179 u32 *power)
180{
181 struct devfreq_cooling_device *dfc = cdev->devdata;
182 struct devfreq *df = dfc->devfreq;
183 struct devfreq_dev_status status;
184 unsigned long state;
185 unsigned long freq;
186 unsigned long voltage;
187 int res, perf_idx;
188
189 mutex_lock(&df->lock);
190 status = df->last_status;
191 mutex_unlock(&df->lock);
192
193 freq = status.current_frequency;
194
195 if (dfc->power_ops && dfc->power_ops->get_real_power) {
196 voltage = get_voltage(df, freq);
197 if (voltage == 0) {
198 res = -EINVAL;
199 goto fail;
200 }
201
202 res = dfc->power_ops->get_real_power(df, power, freq, voltage);
203 if (!res) {
204 state = dfc->capped_state;
205
206 /* Convert EM power into milli-Watts first */
207 dfc->res_util = dfc->em_pd->table[state].power;
208 dfc->res_util /= MICROWATT_PER_MILLIWATT;
209
210 dfc->res_util *= SCALE_ERROR_MITIGATION;
211
212 if (*power > 1)
213 dfc->res_util /= *power;
214 } else {
215 goto fail;
216 }
217 } else {
218 /* Energy Model frequencies are in kHz */
219 perf_idx = get_perf_idx(dfc->em_pd, freq / 1000);
220 if (perf_idx < 0) {
221 res = -EAGAIN;
222 goto fail;
223 }
224
225 _normalize_load(&status);
226
227 /* Convert EM power into milli-Watts first */
228 *power = dfc->em_pd->table[perf_idx].power;
229 *power /= MICROWATT_PER_MILLIWATT;
230 /* Scale power for utilization */
231 *power *= status.busy_time;
232 *power >>= 10;
233 }
234
235 trace_thermal_power_devfreq_get_power(cdev, &status, freq, *power);
236
237 return 0;
238fail:
239 /* It is safe to set max in this case */
240 dfc->res_util = SCALE_ERROR_MITIGATION;
241 return res;
242}
243
244static int devfreq_cooling_state2power(struct thermal_cooling_device *cdev,
245 unsigned long state, u32 *power)
246{
247 struct devfreq_cooling_device *dfc = cdev->devdata;
248 int perf_idx;
249
250 if (state > dfc->max_state)
251 return -EINVAL;
252
253 perf_idx = dfc->max_state - state;
254 *power = dfc->em_pd->table[perf_idx].power;
255 *power /= MICROWATT_PER_MILLIWATT;
256
257 return 0;
258}
259
260static int devfreq_cooling_power2state(struct thermal_cooling_device *cdev,
261 u32 power, unsigned long *state)
262{
263 struct devfreq_cooling_device *dfc = cdev->devdata;
264 struct devfreq *df = dfc->devfreq;
265 struct devfreq_dev_status status;
266 unsigned long freq, em_power_mw;
267 s32 est_power;
268 int i;
269
270 mutex_lock(&df->lock);
271 status = df->last_status;
272 mutex_unlock(&df->lock);
273
274 freq = status.current_frequency;
275
276 if (dfc->power_ops && dfc->power_ops->get_real_power) {
277 /* Scale for resource utilization */
278 est_power = power * dfc->res_util;
279 est_power /= SCALE_ERROR_MITIGATION;
280 } else {
281 /* Scale dynamic power for utilization */
282 _normalize_load(&status);
283 est_power = power << 10;
284 est_power /= status.busy_time;
285 }
286
287 /*
288 * Find the first cooling state that is within the power
289 * budget. The EM power table is sorted ascending.
290 */
291 for (i = dfc->max_state; i > 0; i--) {
292 /* Convert EM power to milli-Watts to make safe comparison */
293 em_power_mw = dfc->em_pd->table[i].power;
294 em_power_mw /= MICROWATT_PER_MILLIWATT;
295 if (est_power >= em_power_mw)
296 break;
297 }
298
299 *state = dfc->max_state - i;
300 dfc->capped_state = *state;
301
302 trace_thermal_power_devfreq_limit(cdev, freq, *state, power);
303 return 0;
304}
305
306/**
307 * devfreq_cooling_gen_tables() - Generate frequency table.
308 * @dfc: Pointer to devfreq cooling device.
309 * @num_opps: Number of OPPs
310 *
311 * Generate frequency table which holds the frequencies in descending
312 * order. That way its indexed by cooling device state. This is for
313 * compatibility with drivers which do not register Energy Model.
314 *
315 * Return: 0 on success, negative error code on failure.
316 */
317static int devfreq_cooling_gen_tables(struct devfreq_cooling_device *dfc,
318 int num_opps)
319{
320 struct devfreq *df = dfc->devfreq;
321 struct device *dev = df->dev.parent;
322 unsigned long freq;
323 int i;
324
325 dfc->freq_table = kcalloc(num_opps, sizeof(*dfc->freq_table),
326 GFP_KERNEL);
327 if (!dfc->freq_table)
328 return -ENOMEM;
329
330 for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) {
331 struct dev_pm_opp *opp;
332
333 opp = dev_pm_opp_find_freq_floor(dev, &freq);
334 if (IS_ERR(opp)) {
335 kfree(dfc->freq_table);
336 return PTR_ERR(opp);
337 }
338
339 dev_pm_opp_put(opp);
340 dfc->freq_table[i] = freq;
341 }
342
343 return 0;
344}
345
346/**
347 * of_devfreq_cooling_register_power() - Register devfreq cooling device,
348 * with OF and power information.
349 * @np: Pointer to OF device_node.
350 * @df: Pointer to devfreq device.
351 * @dfc_power: Pointer to devfreq_cooling_power.
352 *
353 * Register a devfreq cooling device. The available OPPs must be
354 * registered on the device.
355 *
356 * If @dfc_power is provided, the cooling device is registered with the
357 * power extensions. For the power extensions to work correctly,
358 * devfreq should use the simple_ondemand governor, other governors
359 * are not currently supported.
360 */
361struct thermal_cooling_device *
362of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
363 struct devfreq_cooling_power *dfc_power)
364{
365 struct thermal_cooling_device *cdev;
366 struct device *dev = df->dev.parent;
367 struct devfreq_cooling_device *dfc;
368 struct em_perf_domain *em;
369 struct thermal_cooling_device_ops *ops;
370 char *name;
371 int err, num_opps;
372
373
374 dfc = kzalloc(sizeof(*dfc), GFP_KERNEL);
375 if (!dfc)
376 return ERR_PTR(-ENOMEM);
377
378 dfc->devfreq = df;
379
380 ops = &dfc->cooling_ops;
381 ops->get_max_state = devfreq_cooling_get_max_state;
382 ops->get_cur_state = devfreq_cooling_get_cur_state;
383 ops->set_cur_state = devfreq_cooling_set_cur_state;
384
385 em = em_pd_get(dev);
386 if (em && !em_is_artificial(em)) {
387 dfc->em_pd = em;
388 ops->get_requested_power =
389 devfreq_cooling_get_requested_power;
390 ops->state2power = devfreq_cooling_state2power;
391 ops->power2state = devfreq_cooling_power2state;
392
393 dfc->power_ops = dfc_power;
394
395 num_opps = em_pd_nr_perf_states(dfc->em_pd);
396 } else {
397 /* Backward compatibility for drivers which do not use IPA */
398 dev_dbg(dev, "missing proper EM for cooling device\n");
399
400 num_opps = dev_pm_opp_get_opp_count(dev);
401
402 err = devfreq_cooling_gen_tables(dfc, num_opps);
403 if (err)
404 goto free_dfc;
405 }
406
407 if (num_opps <= 0) {
408 err = -EINVAL;
409 goto free_dfc;
410 }
411
412 /* max_state is an index, not a counter */
413 dfc->max_state = num_opps - 1;
414
415 err = dev_pm_qos_add_request(dev, &dfc->req_max_freq,
416 DEV_PM_QOS_MAX_FREQUENCY,
417 PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE);
418 if (err < 0)
419 goto free_table;
420
421 err = -ENOMEM;
422 name = kasprintf(GFP_KERNEL, "devfreq-%s", dev_name(dev));
423 if (!name)
424 goto remove_qos_req;
425
426 cdev = thermal_of_cooling_device_register(np, name, dfc, ops);
427 kfree(name);
428
429 if (IS_ERR(cdev)) {
430 err = PTR_ERR(cdev);
431 dev_err(dev,
432 "Failed to register devfreq cooling device (%d)\n",
433 err);
434 goto remove_qos_req;
435 }
436
437 dfc->cdev = cdev;
438
439 return cdev;
440
441remove_qos_req:
442 dev_pm_qos_remove_request(&dfc->req_max_freq);
443free_table:
444 kfree(dfc->freq_table);
445free_dfc:
446 kfree(dfc);
447
448 return ERR_PTR(err);
449}
450EXPORT_SYMBOL_GPL(of_devfreq_cooling_register_power);
451
452/**
453 * of_devfreq_cooling_register() - Register devfreq cooling device,
454 * with OF information.
455 * @np: Pointer to OF device_node.
456 * @df: Pointer to devfreq device.
457 */
458struct thermal_cooling_device *
459of_devfreq_cooling_register(struct device_node *np, struct devfreq *df)
460{
461 return of_devfreq_cooling_register_power(np, df, NULL);
462}
463EXPORT_SYMBOL_GPL(of_devfreq_cooling_register);
464
465/**
466 * devfreq_cooling_register() - Register devfreq cooling device.
467 * @df: Pointer to devfreq device.
468 */
469struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df)
470{
471 return of_devfreq_cooling_register(NULL, df);
472}
473EXPORT_SYMBOL_GPL(devfreq_cooling_register);
474
475/**
476 * devfreq_cooling_em_register() - Register devfreq cooling device with
477 * power information and automatically register Energy Model (EM)
478 * @df: Pointer to devfreq device.
479 * @dfc_power: Pointer to devfreq_cooling_power.
480 *
481 * Register a devfreq cooling device and automatically register EM. The
482 * available OPPs must be registered for the device.
483 *
484 * If @dfc_power is provided, the cooling device is registered with the
485 * power extensions. It is using the simple Energy Model which requires
486 * "dynamic-power-coefficient" a devicetree property. To not break drivers
487 * which miss that DT property, the function won't bail out when the EM
488 * registration failed. The cooling device will be registered if everything
489 * else is OK.
490 */
491struct thermal_cooling_device *
492devfreq_cooling_em_register(struct devfreq *df,
493 struct devfreq_cooling_power *dfc_power)
494{
495 struct thermal_cooling_device *cdev;
496 struct device *dev;
497 int ret;
498
499 if (IS_ERR_OR_NULL(df))
500 return ERR_PTR(-EINVAL);
501
502 dev = df->dev.parent;
503
504 ret = dev_pm_opp_of_register_em(dev, NULL);
505 if (ret)
506 dev_dbg(dev, "Unable to register EM for devfreq cooling device (%d)\n",
507 ret);
508
509 cdev = of_devfreq_cooling_register_power(dev->of_node, df, dfc_power);
510
511 if (IS_ERR_OR_NULL(cdev))
512 em_dev_unregister_perf_domain(dev);
513
514 return cdev;
515}
516EXPORT_SYMBOL_GPL(devfreq_cooling_em_register);
517
518/**
519 * devfreq_cooling_unregister() - Unregister devfreq cooling device.
520 * @cdev: Pointer to devfreq cooling device to unregister.
521 *
522 * Unregisters devfreq cooling device and related Energy Model if it was
523 * present.
524 */
525void devfreq_cooling_unregister(struct thermal_cooling_device *cdev)
526{
527 struct devfreq_cooling_device *dfc;
528 struct device *dev;
529
530 if (IS_ERR_OR_NULL(cdev))
531 return;
532
533 dfc = cdev->devdata;
534 dev = dfc->devfreq->dev.parent;
535
536 thermal_cooling_device_unregister(dfc->cdev);
537 dev_pm_qos_remove_request(&dfc->req_max_freq);
538
539 em_dev_unregister_perf_domain(dev);
540
541 kfree(dfc->freq_table);
542 kfree(dfc);
543}
544EXPORT_SYMBOL_GPL(devfreq_cooling_unregister);