Merge tag 'iio-fixes-for-6.6a' of https://git.kernel.org/pub/scm/linux/kernel/git...
[platform/kernel/linux-starfive.git] / drivers / thermal / devfreq_cooling.c
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  */
50 struct 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
64 static 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
74 static 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
84 static 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  */
124 static 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
136 static 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
164 static 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
178 static 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;
238 fail:
239         /* It is safe to set max in this case */
240         dfc->res_util = SCALE_ERROR_MITIGATION;
241         return res;
242 }
243
244 static 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
260 static 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  */
317 static 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  */
361 struct thermal_cooling_device *
362 of_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
441 remove_qos_req:
442         dev_pm_qos_remove_request(&dfc->req_max_freq);
443 free_table:
444         kfree(dfc->freq_table);
445 free_dfc:
446         kfree(dfc);
447
448         return ERR_PTR(err);
449 }
450 EXPORT_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  */
458 struct thermal_cooling_device *
459 of_devfreq_cooling_register(struct device_node *np, struct devfreq *df)
460 {
461         return of_devfreq_cooling_register_power(np, df, NULL);
462 }
463 EXPORT_SYMBOL_GPL(of_devfreq_cooling_register);
464
465 /**
466  * devfreq_cooling_register() - Register devfreq cooling device.
467  * @df: Pointer to devfreq device.
468  */
469 struct thermal_cooling_device *devfreq_cooling_register(struct devfreq *df)
470 {
471         return of_devfreq_cooling_register(NULL, df);
472 }
473 EXPORT_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  */
491 struct thermal_cooling_device *
492 devfreq_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 }
516 EXPORT_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  */
525 void 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 }
544 EXPORT_SYMBOL_GPL(devfreq_cooling_unregister);