GNU Linux-libre 6.1.24-gnu
[releases.git] / drivers / thermal / thermal_sysfs.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  thermal.c - sysfs interface of thermal devices
4  *
5  *  Copyright (C) 2016 Eduardo Valentin <edubezval@gmail.com>
6  *
7  *  Highly based on original thermal_core.c
8  *  Copyright (C) 2008 Intel Corp
9  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
10  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
11  */
12
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15 #include <linux/sysfs.h>
16 #include <linux/device.h>
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/jiffies.h>
21
22 #include "thermal_core.h"
23
24 /* sys I/F for thermal zone */
25
26 static ssize_t
27 type_show(struct device *dev, struct device_attribute *attr, char *buf)
28 {
29         struct thermal_zone_device *tz = to_thermal_zone(dev);
30
31         return sprintf(buf, "%s\n", tz->type);
32 }
33
34 static ssize_t
35 temp_show(struct device *dev, struct device_attribute *attr, char *buf)
36 {
37         struct thermal_zone_device *tz = to_thermal_zone(dev);
38         int temperature, ret;
39
40         ret = thermal_zone_get_temp(tz, &temperature);
41
42         if (ret)
43                 return ret;
44
45         return sprintf(buf, "%d\n", temperature);
46 }
47
48 static ssize_t
49 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
50 {
51         struct thermal_zone_device *tz = to_thermal_zone(dev);
52         int enabled;
53
54         mutex_lock(&tz->lock);
55         enabled = thermal_zone_device_is_enabled(tz);
56         mutex_unlock(&tz->lock);
57
58         return sprintf(buf, "%s\n", enabled ? "enabled" : "disabled");
59 }
60
61 static ssize_t
62 mode_store(struct device *dev, struct device_attribute *attr,
63            const char *buf, size_t count)
64 {
65         struct thermal_zone_device *tz = to_thermal_zone(dev);
66         int result;
67
68         if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
69                 result = thermal_zone_device_enable(tz);
70         else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
71                 result = thermal_zone_device_disable(tz);
72         else
73                 result = -EINVAL;
74
75         if (result)
76                 return result;
77
78         return count;
79 }
80
81 static ssize_t
82 trip_point_type_show(struct device *dev, struct device_attribute *attr,
83                      char *buf)
84 {
85         struct thermal_zone_device *tz = to_thermal_zone(dev);
86         enum thermal_trip_type type;
87         int trip, result;
88
89         if (!tz->ops->get_trip_type)
90                 return -EPERM;
91
92         if (sscanf(attr->attr.name, "trip_point_%d_type", &trip) != 1)
93                 return -EINVAL;
94
95         result = tz->ops->get_trip_type(tz, trip, &type);
96         if (result)
97                 return result;
98
99         switch (type) {
100         case THERMAL_TRIP_CRITICAL:
101                 return sprintf(buf, "critical\n");
102         case THERMAL_TRIP_HOT:
103                 return sprintf(buf, "hot\n");
104         case THERMAL_TRIP_PASSIVE:
105                 return sprintf(buf, "passive\n");
106         case THERMAL_TRIP_ACTIVE:
107                 return sprintf(buf, "active\n");
108         default:
109                 return sprintf(buf, "unknown\n");
110         }
111 }
112
113 static ssize_t
114 trip_point_temp_store(struct device *dev, struct device_attribute *attr,
115                       const char *buf, size_t count)
116 {
117         struct thermal_zone_device *tz = to_thermal_zone(dev);
118         int trip, ret;
119         int temperature, hyst = 0;
120         enum thermal_trip_type type;
121
122         if (!tz->ops->set_trip_temp && !tz->trips)
123                 return -EPERM;
124
125         if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
126                 return -EINVAL;
127
128         if (kstrtoint(buf, 10, &temperature))
129                 return -EINVAL;
130
131         if (tz->ops->set_trip_temp) {
132                 ret = tz->ops->set_trip_temp(tz, trip, temperature);
133                 if (ret)
134                         return ret;
135         }
136
137         if (tz->trips)
138                 tz->trips[trip].temperature = temperature;
139
140         if (tz->ops->get_trip_hyst) {
141                 ret = tz->ops->get_trip_hyst(tz, trip, &hyst);
142                 if (ret)
143                         return ret;
144         }
145
146         ret = tz->ops->get_trip_type(tz, trip, &type);
147         if (ret)
148                 return ret;
149
150         thermal_notify_tz_trip_change(tz->id, trip, type, temperature, hyst);
151
152         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
153
154         return count;
155 }
156
157 static ssize_t
158 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
159                      char *buf)
160 {
161         struct thermal_zone_device *tz = to_thermal_zone(dev);
162         int trip, ret;
163         int temperature;
164
165         if (!tz->ops->get_trip_temp)
166                 return -EPERM;
167
168         if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
169                 return -EINVAL;
170
171         ret = tz->ops->get_trip_temp(tz, trip, &temperature);
172
173         if (ret)
174                 return ret;
175
176         return sprintf(buf, "%d\n", temperature);
177 }
178
179 static ssize_t
180 trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
181                       const char *buf, size_t count)
182 {
183         struct thermal_zone_device *tz = to_thermal_zone(dev);
184         int trip, ret;
185         int temperature;
186
187         if (!tz->ops->set_trip_hyst)
188                 return -EPERM;
189
190         if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
191                 return -EINVAL;
192
193         if (kstrtoint(buf, 10, &temperature))
194                 return -EINVAL;
195
196         /*
197          * We are not doing any check on the 'temperature' value
198          * here. The driver implementing 'set_trip_hyst' has to
199          * take care of this.
200          */
201         ret = tz->ops->set_trip_hyst(tz, trip, temperature);
202
203         if (!ret)
204                 thermal_zone_set_trips(tz);
205
206         return ret ? ret : count;
207 }
208
209 static ssize_t
210 trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
211                      char *buf)
212 {
213         struct thermal_zone_device *tz = to_thermal_zone(dev);
214         int trip, ret;
215         int temperature;
216
217         if (!tz->ops->get_trip_hyst)
218                 return -EPERM;
219
220         if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
221                 return -EINVAL;
222
223         ret = tz->ops->get_trip_hyst(tz, trip, &temperature);
224
225         return ret ? ret : sprintf(buf, "%d\n", temperature);
226 }
227
228 static ssize_t
229 policy_store(struct device *dev, struct device_attribute *attr,
230              const char *buf, size_t count)
231 {
232         struct thermal_zone_device *tz = to_thermal_zone(dev);
233         char name[THERMAL_NAME_LENGTH];
234         int ret;
235
236         snprintf(name, sizeof(name), "%s", buf);
237
238         ret = thermal_zone_device_set_policy(tz, name);
239         if (!ret)
240                 ret = count;
241
242         return ret;
243 }
244
245 static ssize_t
246 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
247 {
248         struct thermal_zone_device *tz = to_thermal_zone(dev);
249
250         return sprintf(buf, "%s\n", tz->governor->name);
251 }
252
253 static ssize_t
254 available_policies_show(struct device *dev, struct device_attribute *devattr,
255                         char *buf)
256 {
257         return thermal_build_list_of_policies(buf);
258 }
259
260 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
261 static ssize_t
262 emul_temp_store(struct device *dev, struct device_attribute *attr,
263                 const char *buf, size_t count)
264 {
265         struct thermal_zone_device *tz = to_thermal_zone(dev);
266         int ret = 0;
267         int temperature;
268
269         if (kstrtoint(buf, 10, &temperature))
270                 return -EINVAL;
271
272         if (!tz->ops->set_emul_temp) {
273                 mutex_lock(&tz->lock);
274                 tz->emul_temperature = temperature;
275                 mutex_unlock(&tz->lock);
276         } else {
277                 ret = tz->ops->set_emul_temp(tz, temperature);
278         }
279
280         if (!ret)
281                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
282
283         return ret ? ret : count;
284 }
285 static DEVICE_ATTR_WO(emul_temp);
286 #endif
287
288 static ssize_t
289 sustainable_power_show(struct device *dev, struct device_attribute *devattr,
290                        char *buf)
291 {
292         struct thermal_zone_device *tz = to_thermal_zone(dev);
293
294         if (tz->tzp)
295                 return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
296         else
297                 return -EIO;
298 }
299
300 static ssize_t
301 sustainable_power_store(struct device *dev, struct device_attribute *devattr,
302                         const char *buf, size_t count)
303 {
304         struct thermal_zone_device *tz = to_thermal_zone(dev);
305         u32 sustainable_power;
306
307         if (!tz->tzp)
308                 return -EIO;
309
310         if (kstrtou32(buf, 10, &sustainable_power))
311                 return -EINVAL;
312
313         tz->tzp->sustainable_power = sustainable_power;
314
315         return count;
316 }
317
318 #define create_s32_tzp_attr(name)                                       \
319         static ssize_t                                                  \
320         name##_show(struct device *dev, struct device_attribute *devattr, \
321                 char *buf)                                              \
322         {                                                               \
323         struct thermal_zone_device *tz = to_thermal_zone(dev);          \
324                                                                         \
325         if (tz->tzp)                                                    \
326                 return sprintf(buf, "%d\n", tz->tzp->name);             \
327         else                                                            \
328                 return -EIO;                                            \
329         }                                                               \
330                                                                         \
331         static ssize_t                                                  \
332         name##_store(struct device *dev, struct device_attribute *devattr, \
333                 const char *buf, size_t count)                          \
334         {                                                               \
335                 struct thermal_zone_device *tz = to_thermal_zone(dev);  \
336                 s32 value;                                              \
337                                                                         \
338                 if (!tz->tzp)                                           \
339                         return -EIO;                                    \
340                                                                         \
341                 if (kstrtos32(buf, 10, &value))                         \
342                         return -EINVAL;                                 \
343                                                                         \
344                 tz->tzp->name = value;                                  \
345                                                                         \
346                 return count;                                           \
347         }                                                               \
348         static DEVICE_ATTR_RW(name)
349
350 create_s32_tzp_attr(k_po);
351 create_s32_tzp_attr(k_pu);
352 create_s32_tzp_attr(k_i);
353 create_s32_tzp_attr(k_d);
354 create_s32_tzp_attr(integral_cutoff);
355 create_s32_tzp_attr(slope);
356 create_s32_tzp_attr(offset);
357 #undef create_s32_tzp_attr
358
359 /*
360  * These are thermal zone device attributes that will always be present.
361  * All the attributes created for tzp (create_s32_tzp_attr) also are always
362  * present on the sysfs interface.
363  */
364 static DEVICE_ATTR_RO(type);
365 static DEVICE_ATTR_RO(temp);
366 static DEVICE_ATTR_RW(policy);
367 static DEVICE_ATTR_RO(available_policies);
368 static DEVICE_ATTR_RW(sustainable_power);
369
370 /* These thermal zone device attributes are created based on conditions */
371 static DEVICE_ATTR_RW(mode);
372
373 /* These attributes are unconditionally added to a thermal zone */
374 static struct attribute *thermal_zone_dev_attrs[] = {
375         &dev_attr_type.attr,
376         &dev_attr_temp.attr,
377 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
378         &dev_attr_emul_temp.attr,
379 #endif
380         &dev_attr_policy.attr,
381         &dev_attr_available_policies.attr,
382         &dev_attr_sustainable_power.attr,
383         &dev_attr_k_po.attr,
384         &dev_attr_k_pu.attr,
385         &dev_attr_k_i.attr,
386         &dev_attr_k_d.attr,
387         &dev_attr_integral_cutoff.attr,
388         &dev_attr_slope.attr,
389         &dev_attr_offset.attr,
390         NULL,
391 };
392
393 static const struct attribute_group thermal_zone_attribute_group = {
394         .attrs = thermal_zone_dev_attrs,
395 };
396
397 static struct attribute *thermal_zone_mode_attrs[] = {
398         &dev_attr_mode.attr,
399         NULL,
400 };
401
402 static const struct attribute_group thermal_zone_mode_attribute_group = {
403         .attrs = thermal_zone_mode_attrs,
404 };
405
406 static const struct attribute_group *thermal_zone_attribute_groups[] = {
407         &thermal_zone_attribute_group,
408         &thermal_zone_mode_attribute_group,
409         /* This is not NULL terminated as we create the group dynamically */
410 };
411
412 /**
413  * create_trip_attrs() - create attributes for trip points
414  * @tz:         the thermal zone device
415  * @mask:       Writeable trip point bitmap.
416  *
417  * helper function to instantiate sysfs entries for every trip
418  * point and its properties of a struct thermal_zone_device.
419  *
420  * Return: 0 on success, the proper error value otherwise.
421  */
422 static int create_trip_attrs(struct thermal_zone_device *tz, int mask)
423 {
424         struct attribute **attrs;
425         int indx;
426
427         /* This function works only for zones with at least one trip */
428         if (tz->num_trips <= 0)
429                 return -EINVAL;
430
431         tz->trip_type_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_type_attrs),
432                                       GFP_KERNEL);
433         if (!tz->trip_type_attrs)
434                 return -ENOMEM;
435
436         tz->trip_temp_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_temp_attrs),
437                                       GFP_KERNEL);
438         if (!tz->trip_temp_attrs) {
439                 kfree(tz->trip_type_attrs);
440                 return -ENOMEM;
441         }
442
443         if (tz->ops->get_trip_hyst) {
444                 tz->trip_hyst_attrs = kcalloc(tz->num_trips,
445                                               sizeof(*tz->trip_hyst_attrs),
446                                               GFP_KERNEL);
447                 if (!tz->trip_hyst_attrs) {
448                         kfree(tz->trip_type_attrs);
449                         kfree(tz->trip_temp_attrs);
450                         return -ENOMEM;
451                 }
452         }
453
454         attrs = kcalloc(tz->num_trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
455         if (!attrs) {
456                 kfree(tz->trip_type_attrs);
457                 kfree(tz->trip_temp_attrs);
458                 if (tz->ops->get_trip_hyst)
459                         kfree(tz->trip_hyst_attrs);
460                 return -ENOMEM;
461         }
462
463         for (indx = 0; indx < tz->num_trips; indx++) {
464                 /* create trip type attribute */
465                 snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
466                          "trip_point_%d_type", indx);
467
468                 sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
469                 tz->trip_type_attrs[indx].attr.attr.name =
470                                                 tz->trip_type_attrs[indx].name;
471                 tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
472                 tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
473                 attrs[indx] = &tz->trip_type_attrs[indx].attr.attr;
474
475                 /* create trip temp attribute */
476                 snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
477                          "trip_point_%d_temp", indx);
478
479                 sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
480                 tz->trip_temp_attrs[indx].attr.attr.name =
481                                                 tz->trip_temp_attrs[indx].name;
482                 tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
483                 tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
484                 if (IS_ENABLED(CONFIG_THERMAL_WRITABLE_TRIPS) &&
485                     mask & (1 << indx)) {
486                         tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
487                         tz->trip_temp_attrs[indx].attr.store =
488                                                         trip_point_temp_store;
489                 }
490                 attrs[indx + tz->num_trips] = &tz->trip_temp_attrs[indx].attr.attr;
491
492                 /* create Optional trip hyst attribute */
493                 if (!tz->ops->get_trip_hyst)
494                         continue;
495                 snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH,
496                          "trip_point_%d_hyst", indx);
497
498                 sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr);
499                 tz->trip_hyst_attrs[indx].attr.attr.name =
500                                         tz->trip_hyst_attrs[indx].name;
501                 tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO;
502                 tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show;
503                 if (tz->ops->set_trip_hyst) {
504                         tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR;
505                         tz->trip_hyst_attrs[indx].attr.store =
506                                         trip_point_hyst_store;
507                 }
508                 attrs[indx + tz->num_trips * 2] =
509                                         &tz->trip_hyst_attrs[indx].attr.attr;
510         }
511         attrs[tz->num_trips * 3] = NULL;
512
513         tz->trips_attribute_group.attrs = attrs;
514
515         return 0;
516 }
517
518 /**
519  * destroy_trip_attrs() - destroy attributes for trip points
520  * @tz:         the thermal zone device
521  *
522  * helper function to free resources allocated by create_trip_attrs()
523  */
524 static void destroy_trip_attrs(struct thermal_zone_device *tz)
525 {
526         if (!tz)
527                 return;
528
529         kfree(tz->trip_type_attrs);
530         kfree(tz->trip_temp_attrs);
531         if (tz->ops->get_trip_hyst)
532                 kfree(tz->trip_hyst_attrs);
533         kfree(tz->trips_attribute_group.attrs);
534 }
535
536 int thermal_zone_create_device_groups(struct thermal_zone_device *tz,
537                                       int mask)
538 {
539         const struct attribute_group **groups;
540         int i, size, result;
541
542         /* we need one extra for trips and the NULL to terminate the array */
543         size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
544         /* This also takes care of API requirement to be NULL terminated */
545         groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
546         if (!groups)
547                 return -ENOMEM;
548
549         for (i = 0; i < size - 2; i++)
550                 groups[i] = thermal_zone_attribute_groups[i];
551
552         if (tz->num_trips) {
553                 result = create_trip_attrs(tz, mask);
554                 if (result) {
555                         kfree(groups);
556
557                         return result;
558                 }
559
560                 groups[size - 2] = &tz->trips_attribute_group;
561         }
562
563         tz->device.groups = groups;
564
565         return 0;
566 }
567
568 void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
569 {
570         if (!tz)
571                 return;
572
573         if (tz->num_trips)
574                 destroy_trip_attrs(tz);
575
576         kfree(tz->device.groups);
577 }
578
579 /* sys I/F for cooling device */
580 static ssize_t
581 cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
582 {
583         struct thermal_cooling_device *cdev = to_cooling_device(dev);
584
585         return sprintf(buf, "%s\n", cdev->type);
586 }
587
588 static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
589                               char *buf)
590 {
591         struct thermal_cooling_device *cdev = to_cooling_device(dev);
592
593         return sprintf(buf, "%ld\n", cdev->max_state);
594 }
595
596 static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
597                               char *buf)
598 {
599         struct thermal_cooling_device *cdev = to_cooling_device(dev);
600         unsigned long state;
601         int ret;
602
603         ret = cdev->ops->get_cur_state(cdev, &state);
604         if (ret)
605                 return ret;
606         return sprintf(buf, "%ld\n", state);
607 }
608
609 static ssize_t
610 cur_state_store(struct device *dev, struct device_attribute *attr,
611                 const char *buf, size_t count)
612 {
613         struct thermal_cooling_device *cdev = to_cooling_device(dev);
614         unsigned long state;
615         int result;
616
617         if (sscanf(buf, "%ld\n", &state) != 1)
618                 return -EINVAL;
619
620         if ((long)state < 0)
621                 return -EINVAL;
622
623         /* Requested state should be less than max_state + 1 */
624         if (state > cdev->max_state)
625                 return -EINVAL;
626
627         mutex_lock(&cdev->lock);
628
629         result = cdev->ops->set_cur_state(cdev, state);
630         if (!result)
631                 thermal_cooling_device_stats_update(cdev, state);
632
633         mutex_unlock(&cdev->lock);
634         return result ? result : count;
635 }
636
637 static struct device_attribute
638 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
639 static DEVICE_ATTR_RO(max_state);
640 static DEVICE_ATTR_RW(cur_state);
641
642 static struct attribute *cooling_device_attrs[] = {
643         &dev_attr_cdev_type.attr,
644         &dev_attr_max_state.attr,
645         &dev_attr_cur_state.attr,
646         NULL,
647 };
648
649 static const struct attribute_group cooling_device_attr_group = {
650         .attrs = cooling_device_attrs,
651 };
652
653 static const struct attribute_group *cooling_device_attr_groups[] = {
654         &cooling_device_attr_group,
655         NULL, /* Space allocated for cooling_device_stats_attr_group */
656         NULL,
657 };
658
659 #ifdef CONFIG_THERMAL_STATISTICS
660 struct cooling_dev_stats {
661         spinlock_t lock;
662         unsigned int total_trans;
663         unsigned long state;
664         unsigned long max_states;
665         ktime_t last_time;
666         ktime_t *time_in_state;
667         unsigned int *trans_table;
668 };
669
670 static void update_time_in_state(struct cooling_dev_stats *stats)
671 {
672         ktime_t now = ktime_get(), delta;
673
674         delta = ktime_sub(now, stats->last_time);
675         stats->time_in_state[stats->state] =
676                 ktime_add(stats->time_in_state[stats->state], delta);
677         stats->last_time = now;
678 }
679
680 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
681                                          unsigned long new_state)
682 {
683         struct cooling_dev_stats *stats = cdev->stats;
684
685         if (!stats)
686                 return;
687
688         spin_lock(&stats->lock);
689
690         if (stats->state == new_state)
691                 goto unlock;
692
693         update_time_in_state(stats);
694         stats->trans_table[stats->state * stats->max_states + new_state]++;
695         stats->state = new_state;
696         stats->total_trans++;
697
698 unlock:
699         spin_unlock(&stats->lock);
700 }
701
702 static ssize_t total_trans_show(struct device *dev,
703                                 struct device_attribute *attr, char *buf)
704 {
705         struct thermal_cooling_device *cdev = to_cooling_device(dev);
706         struct cooling_dev_stats *stats = cdev->stats;
707         int ret;
708
709         spin_lock(&stats->lock);
710         ret = sprintf(buf, "%u\n", stats->total_trans);
711         spin_unlock(&stats->lock);
712
713         return ret;
714 }
715
716 static ssize_t
717 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
718                       char *buf)
719 {
720         struct thermal_cooling_device *cdev = to_cooling_device(dev);
721         struct cooling_dev_stats *stats = cdev->stats;
722         ssize_t len = 0;
723         int i;
724
725         spin_lock(&stats->lock);
726         update_time_in_state(stats);
727
728         for (i = 0; i < stats->max_states; i++) {
729                 len += sprintf(buf + len, "state%u\t%llu\n", i,
730                                ktime_to_ms(stats->time_in_state[i]));
731         }
732         spin_unlock(&stats->lock);
733
734         return len;
735 }
736
737 static ssize_t
738 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
739             size_t count)
740 {
741         struct thermal_cooling_device *cdev = to_cooling_device(dev);
742         struct cooling_dev_stats *stats = cdev->stats;
743         int i, states = stats->max_states;
744
745         spin_lock(&stats->lock);
746
747         stats->total_trans = 0;
748         stats->last_time = ktime_get();
749         memset(stats->trans_table, 0,
750                states * states * sizeof(*stats->trans_table));
751
752         for (i = 0; i < stats->max_states; i++)
753                 stats->time_in_state[i] = ktime_set(0, 0);
754
755         spin_unlock(&stats->lock);
756
757         return count;
758 }
759
760 static ssize_t trans_table_show(struct device *dev,
761                                 struct device_attribute *attr, char *buf)
762 {
763         struct thermal_cooling_device *cdev = to_cooling_device(dev);
764         struct cooling_dev_stats *stats = cdev->stats;
765         ssize_t len = 0;
766         int i, j;
767
768         len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
769         len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
770         for (i = 0; i < stats->max_states; i++) {
771                 if (len >= PAGE_SIZE)
772                         break;
773                 len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
774         }
775         if (len >= PAGE_SIZE)
776                 return PAGE_SIZE;
777
778         len += snprintf(buf + len, PAGE_SIZE - len, "\n");
779
780         for (i = 0; i < stats->max_states; i++) {
781                 if (len >= PAGE_SIZE)
782                         break;
783
784                 len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
785
786                 for (j = 0; j < stats->max_states; j++) {
787                         if (len >= PAGE_SIZE)
788                                 break;
789                         len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
790                                 stats->trans_table[i * stats->max_states + j]);
791                 }
792                 if (len >= PAGE_SIZE)
793                         break;
794                 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
795         }
796
797         if (len >= PAGE_SIZE) {
798                 pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
799                 return -EFBIG;
800         }
801         return len;
802 }
803
804 static DEVICE_ATTR_RO(total_trans);
805 static DEVICE_ATTR_RO(time_in_state_ms);
806 static DEVICE_ATTR_WO(reset);
807 static DEVICE_ATTR_RO(trans_table);
808
809 static struct attribute *cooling_device_stats_attrs[] = {
810         &dev_attr_total_trans.attr,
811         &dev_attr_time_in_state_ms.attr,
812         &dev_attr_reset.attr,
813         &dev_attr_trans_table.attr,
814         NULL
815 };
816
817 static const struct attribute_group cooling_device_stats_attr_group = {
818         .attrs = cooling_device_stats_attrs,
819         .name = "stats"
820 };
821
822 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
823 {
824         const struct attribute_group *stats_attr_group = NULL;
825         struct cooling_dev_stats *stats;
826         unsigned long states;
827         int var;
828
829         if (cdev->ops->get_max_state(cdev, &states))
830                 goto out;
831
832         states++; /* Total number of states is highest state + 1 */
833
834         var = sizeof(*stats);
835         var += sizeof(*stats->time_in_state) * states;
836         var += sizeof(*stats->trans_table) * states * states;
837
838         stats = kzalloc(var, GFP_KERNEL);
839         if (!stats)
840                 goto out;
841
842         stats->time_in_state = (ktime_t *)(stats + 1);
843         stats->trans_table = (unsigned int *)(stats->time_in_state + states);
844         cdev->stats = stats;
845         stats->last_time = ktime_get();
846         stats->max_states = states;
847
848         spin_lock_init(&stats->lock);
849
850         stats_attr_group = &cooling_device_stats_attr_group;
851
852 out:
853         /* Fill the empty slot left in cooling_device_attr_groups */
854         var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
855         cooling_device_attr_groups[var] = stats_attr_group;
856 }
857
858 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
859 {
860         kfree(cdev->stats);
861         cdev->stats = NULL;
862 }
863
864 #else
865
866 static inline void
867 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
868 static inline void
869 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
870
871 #endif /* CONFIG_THERMAL_STATISTICS */
872
873 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
874 {
875         cooling_device_stats_setup(cdev);
876         cdev->device.groups = cooling_device_attr_groups;
877 }
878
879 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
880 {
881         cooling_device_stats_destroy(cdev);
882 }
883
884 /* these helper will be used only at the time of bindig */
885 ssize_t
886 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
887 {
888         struct thermal_instance *instance;
889
890         instance =
891             container_of(attr, struct thermal_instance, attr);
892
893         return sprintf(buf, "%d\n", instance->trip);
894 }
895
896 ssize_t
897 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
898 {
899         struct thermal_instance *instance;
900
901         instance = container_of(attr, struct thermal_instance, weight_attr);
902
903         return sprintf(buf, "%d\n", instance->weight);
904 }
905
906 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
907                      const char *buf, size_t count)
908 {
909         struct thermal_instance *instance;
910         int ret, weight;
911
912         ret = kstrtoint(buf, 0, &weight);
913         if (ret)
914                 return ret;
915
916         instance = container_of(attr, struct thermal_instance, weight_attr);
917         instance->weight = weight;
918
919         return count;
920 }