Merge tag 'for-5.18/io_uring-2022-04-01' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.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 = thermal_zone_device_is_enabled(tz);
53
54         return sprintf(buf, "%s\n", enabled ? "enabled" : "disabled");
55 }
56
57 static ssize_t
58 mode_store(struct device *dev, struct device_attribute *attr,
59            const char *buf, size_t count)
60 {
61         struct thermal_zone_device *tz = to_thermal_zone(dev);
62         int result;
63
64         if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
65                 result = thermal_zone_device_enable(tz);
66         else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
67                 result = thermal_zone_device_disable(tz);
68         else
69                 result = -EINVAL;
70
71         if (result)
72                 return result;
73
74         return count;
75 }
76
77 static ssize_t
78 trip_point_type_show(struct device *dev, struct device_attribute *attr,
79                      char *buf)
80 {
81         struct thermal_zone_device *tz = to_thermal_zone(dev);
82         enum thermal_trip_type type;
83         int trip, result;
84
85         if (!tz->ops->get_trip_type)
86                 return -EPERM;
87
88         if (sscanf(attr->attr.name, "trip_point_%d_type", &trip) != 1)
89                 return -EINVAL;
90
91         result = tz->ops->get_trip_type(tz, trip, &type);
92         if (result)
93                 return result;
94
95         switch (type) {
96         case THERMAL_TRIP_CRITICAL:
97                 return sprintf(buf, "critical\n");
98         case THERMAL_TRIP_HOT:
99                 return sprintf(buf, "hot\n");
100         case THERMAL_TRIP_PASSIVE:
101                 return sprintf(buf, "passive\n");
102         case THERMAL_TRIP_ACTIVE:
103                 return sprintf(buf, "active\n");
104         default:
105                 return sprintf(buf, "unknown\n");
106         }
107 }
108
109 static ssize_t
110 trip_point_temp_store(struct device *dev, struct device_attribute *attr,
111                       const char *buf, size_t count)
112 {
113         struct thermal_zone_device *tz = to_thermal_zone(dev);
114         int trip, ret;
115         int temperature, hyst = 0;
116         enum thermal_trip_type type;
117
118         if (!tz->ops->set_trip_temp)
119                 return -EPERM;
120
121         if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
122                 return -EINVAL;
123
124         if (kstrtoint(buf, 10, &temperature))
125                 return -EINVAL;
126
127         ret = tz->ops->set_trip_temp(tz, trip, temperature);
128         if (ret)
129                 return ret;
130
131         if (tz->ops->get_trip_hyst) {
132                 ret = tz->ops->get_trip_hyst(tz, trip, &hyst);
133                 if (ret)
134                         return ret;
135         }
136
137         ret = tz->ops->get_trip_type(tz, trip, &type);
138         if (ret)
139                 return ret;
140
141         thermal_notify_tz_trip_change(tz->id, trip, type, temperature, hyst);
142
143         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
144
145         return count;
146 }
147
148 static ssize_t
149 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
150                      char *buf)
151 {
152         struct thermal_zone_device *tz = to_thermal_zone(dev);
153         int trip, ret;
154         int temperature;
155
156         if (!tz->ops->get_trip_temp)
157                 return -EPERM;
158
159         if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip) != 1)
160                 return -EINVAL;
161
162         ret = tz->ops->get_trip_temp(tz, trip, &temperature);
163
164         if (ret)
165                 return ret;
166
167         return sprintf(buf, "%d\n", temperature);
168 }
169
170 static ssize_t
171 trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
172                       const char *buf, size_t count)
173 {
174         struct thermal_zone_device *tz = to_thermal_zone(dev);
175         int trip, ret;
176         int temperature;
177
178         if (!tz->ops->set_trip_hyst)
179                 return -EPERM;
180
181         if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
182                 return -EINVAL;
183
184         if (kstrtoint(buf, 10, &temperature))
185                 return -EINVAL;
186
187         /*
188          * We are not doing any check on the 'temperature' value
189          * here. The driver implementing 'set_trip_hyst' has to
190          * take care of this.
191          */
192         ret = tz->ops->set_trip_hyst(tz, trip, temperature);
193
194         if (!ret)
195                 thermal_zone_set_trips(tz);
196
197         return ret ? ret : count;
198 }
199
200 static ssize_t
201 trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
202                      char *buf)
203 {
204         struct thermal_zone_device *tz = to_thermal_zone(dev);
205         int trip, ret;
206         int temperature;
207
208         if (!tz->ops->get_trip_hyst)
209                 return -EPERM;
210
211         if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip) != 1)
212                 return -EINVAL;
213
214         ret = tz->ops->get_trip_hyst(tz, trip, &temperature);
215
216         return ret ? ret : sprintf(buf, "%d\n", temperature);
217 }
218
219 static ssize_t
220 policy_store(struct device *dev, struct device_attribute *attr,
221              const char *buf, size_t count)
222 {
223         struct thermal_zone_device *tz = to_thermal_zone(dev);
224         char name[THERMAL_NAME_LENGTH];
225         int ret;
226
227         snprintf(name, sizeof(name), "%s", buf);
228
229         ret = thermal_zone_device_set_policy(tz, name);
230         if (!ret)
231                 ret = count;
232
233         return ret;
234 }
235
236 static ssize_t
237 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
238 {
239         struct thermal_zone_device *tz = to_thermal_zone(dev);
240
241         return sprintf(buf, "%s\n", tz->governor->name);
242 }
243
244 static ssize_t
245 available_policies_show(struct device *dev, struct device_attribute *devattr,
246                         char *buf)
247 {
248         return thermal_build_list_of_policies(buf);
249 }
250
251 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
252 static ssize_t
253 emul_temp_store(struct device *dev, struct device_attribute *attr,
254                 const char *buf, size_t count)
255 {
256         struct thermal_zone_device *tz = to_thermal_zone(dev);
257         int ret = 0;
258         int temperature;
259
260         if (kstrtoint(buf, 10, &temperature))
261                 return -EINVAL;
262
263         if (!tz->ops->set_emul_temp) {
264                 mutex_lock(&tz->lock);
265                 tz->emul_temperature = temperature;
266                 mutex_unlock(&tz->lock);
267         } else {
268                 ret = tz->ops->set_emul_temp(tz, temperature);
269         }
270
271         if (!ret)
272                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
273
274         return ret ? ret : count;
275 }
276 static DEVICE_ATTR_WO(emul_temp);
277 #endif
278
279 static ssize_t
280 sustainable_power_show(struct device *dev, struct device_attribute *devattr,
281                        char *buf)
282 {
283         struct thermal_zone_device *tz = to_thermal_zone(dev);
284
285         if (tz->tzp)
286                 return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
287         else
288                 return -EIO;
289 }
290
291 static ssize_t
292 sustainable_power_store(struct device *dev, struct device_attribute *devattr,
293                         const char *buf, size_t count)
294 {
295         struct thermal_zone_device *tz = to_thermal_zone(dev);
296         u32 sustainable_power;
297
298         if (!tz->tzp)
299                 return -EIO;
300
301         if (kstrtou32(buf, 10, &sustainable_power))
302                 return -EINVAL;
303
304         tz->tzp->sustainable_power = sustainable_power;
305
306         return count;
307 }
308
309 #define create_s32_tzp_attr(name)                                       \
310         static ssize_t                                                  \
311         name##_show(struct device *dev, struct device_attribute *devattr, \
312                 char *buf)                                              \
313         {                                                               \
314         struct thermal_zone_device *tz = to_thermal_zone(dev);          \
315                                                                         \
316         if (tz->tzp)                                                    \
317                 return sprintf(buf, "%d\n", tz->tzp->name);             \
318         else                                                            \
319                 return -EIO;                                            \
320         }                                                               \
321                                                                         \
322         static ssize_t                                                  \
323         name##_store(struct device *dev, struct device_attribute *devattr, \
324                 const char *buf, size_t count)                          \
325         {                                                               \
326                 struct thermal_zone_device *tz = to_thermal_zone(dev);  \
327                 s32 value;                                              \
328                                                                         \
329                 if (!tz->tzp)                                           \
330                         return -EIO;                                    \
331                                                                         \
332                 if (kstrtos32(buf, 10, &value))                         \
333                         return -EINVAL;                                 \
334                                                                         \
335                 tz->tzp->name = value;                                  \
336                                                                         \
337                 return count;                                           \
338         }                                                               \
339         static DEVICE_ATTR_RW(name)
340
341 create_s32_tzp_attr(k_po);
342 create_s32_tzp_attr(k_pu);
343 create_s32_tzp_attr(k_i);
344 create_s32_tzp_attr(k_d);
345 create_s32_tzp_attr(integral_cutoff);
346 create_s32_tzp_attr(slope);
347 create_s32_tzp_attr(offset);
348 #undef create_s32_tzp_attr
349
350 /*
351  * These are thermal zone device attributes that will always be present.
352  * All the attributes created for tzp (create_s32_tzp_attr) also are always
353  * present on the sysfs interface.
354  */
355 static DEVICE_ATTR_RO(type);
356 static DEVICE_ATTR_RO(temp);
357 static DEVICE_ATTR_RW(policy);
358 static DEVICE_ATTR_RO(available_policies);
359 static DEVICE_ATTR_RW(sustainable_power);
360
361 /* These thermal zone device attributes are created based on conditions */
362 static DEVICE_ATTR_RW(mode);
363
364 /* These attributes are unconditionally added to a thermal zone */
365 static struct attribute *thermal_zone_dev_attrs[] = {
366         &dev_attr_type.attr,
367         &dev_attr_temp.attr,
368 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
369         &dev_attr_emul_temp.attr,
370 #endif
371         &dev_attr_policy.attr,
372         &dev_attr_available_policies.attr,
373         &dev_attr_sustainable_power.attr,
374         &dev_attr_k_po.attr,
375         &dev_attr_k_pu.attr,
376         &dev_attr_k_i.attr,
377         &dev_attr_k_d.attr,
378         &dev_attr_integral_cutoff.attr,
379         &dev_attr_slope.attr,
380         &dev_attr_offset.attr,
381         NULL,
382 };
383
384 static const struct attribute_group thermal_zone_attribute_group = {
385         .attrs = thermal_zone_dev_attrs,
386 };
387
388 static struct attribute *thermal_zone_mode_attrs[] = {
389         &dev_attr_mode.attr,
390         NULL,
391 };
392
393 static const struct attribute_group thermal_zone_mode_attribute_group = {
394         .attrs = thermal_zone_mode_attrs,
395 };
396
397 static const struct attribute_group *thermal_zone_attribute_groups[] = {
398         &thermal_zone_attribute_group,
399         &thermal_zone_mode_attribute_group,
400         /* This is not NULL terminated as we create the group dynamically */
401 };
402
403 /**
404  * create_trip_attrs() - create attributes for trip points
405  * @tz:         the thermal zone device
406  * @mask:       Writeable trip point bitmap.
407  *
408  * helper function to instantiate sysfs entries for every trip
409  * point and its properties of a struct thermal_zone_device.
410  *
411  * Return: 0 on success, the proper error value otherwise.
412  */
413 static int create_trip_attrs(struct thermal_zone_device *tz, int mask)
414 {
415         struct attribute **attrs;
416         int indx;
417
418         /* This function works only for zones with at least one trip */
419         if (tz->trips <= 0)
420                 return -EINVAL;
421
422         tz->trip_type_attrs = kcalloc(tz->trips, sizeof(*tz->trip_type_attrs),
423                                       GFP_KERNEL);
424         if (!tz->trip_type_attrs)
425                 return -ENOMEM;
426
427         tz->trip_temp_attrs = kcalloc(tz->trips, sizeof(*tz->trip_temp_attrs),
428                                       GFP_KERNEL);
429         if (!tz->trip_temp_attrs) {
430                 kfree(tz->trip_type_attrs);
431                 return -ENOMEM;
432         }
433
434         if (tz->ops->get_trip_hyst) {
435                 tz->trip_hyst_attrs = kcalloc(tz->trips,
436                                               sizeof(*tz->trip_hyst_attrs),
437                                               GFP_KERNEL);
438                 if (!tz->trip_hyst_attrs) {
439                         kfree(tz->trip_type_attrs);
440                         kfree(tz->trip_temp_attrs);
441                         return -ENOMEM;
442                 }
443         }
444
445         attrs = kcalloc(tz->trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
446         if (!attrs) {
447                 kfree(tz->trip_type_attrs);
448                 kfree(tz->trip_temp_attrs);
449                 if (tz->ops->get_trip_hyst)
450                         kfree(tz->trip_hyst_attrs);
451                 return -ENOMEM;
452         }
453
454         for (indx = 0; indx < tz->trips; indx++) {
455                 /* create trip type attribute */
456                 snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
457                          "trip_point_%d_type", indx);
458
459                 sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
460                 tz->trip_type_attrs[indx].attr.attr.name =
461                                                 tz->trip_type_attrs[indx].name;
462                 tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
463                 tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
464                 attrs[indx] = &tz->trip_type_attrs[indx].attr.attr;
465
466                 /* create trip temp attribute */
467                 snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
468                          "trip_point_%d_temp", indx);
469
470                 sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
471                 tz->trip_temp_attrs[indx].attr.attr.name =
472                                                 tz->trip_temp_attrs[indx].name;
473                 tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
474                 tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
475                 if (IS_ENABLED(CONFIG_THERMAL_WRITABLE_TRIPS) &&
476                     mask & (1 << indx)) {
477                         tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
478                         tz->trip_temp_attrs[indx].attr.store =
479                                                         trip_point_temp_store;
480                 }
481                 attrs[indx + tz->trips] = &tz->trip_temp_attrs[indx].attr.attr;
482
483                 /* create Optional trip hyst attribute */
484                 if (!tz->ops->get_trip_hyst)
485                         continue;
486                 snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH,
487                          "trip_point_%d_hyst", indx);
488
489                 sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr);
490                 tz->trip_hyst_attrs[indx].attr.attr.name =
491                                         tz->trip_hyst_attrs[indx].name;
492                 tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO;
493                 tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show;
494                 if (tz->ops->set_trip_hyst) {
495                         tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR;
496                         tz->trip_hyst_attrs[indx].attr.store =
497                                         trip_point_hyst_store;
498                 }
499                 attrs[indx + tz->trips * 2] =
500                                         &tz->trip_hyst_attrs[indx].attr.attr;
501         }
502         attrs[tz->trips * 3] = NULL;
503
504         tz->trips_attribute_group.attrs = attrs;
505
506         return 0;
507 }
508
509 /**
510  * destroy_trip_attrs() - destroy attributes for trip points
511  * @tz:         the thermal zone device
512  *
513  * helper function to free resources allocated by create_trip_attrs()
514  */
515 static void destroy_trip_attrs(struct thermal_zone_device *tz)
516 {
517         if (!tz)
518                 return;
519
520         kfree(tz->trip_type_attrs);
521         kfree(tz->trip_temp_attrs);
522         if (tz->ops->get_trip_hyst)
523                 kfree(tz->trip_hyst_attrs);
524         kfree(tz->trips_attribute_group.attrs);
525 }
526
527 int thermal_zone_create_device_groups(struct thermal_zone_device *tz,
528                                       int mask)
529 {
530         const struct attribute_group **groups;
531         int i, size, result;
532
533         /* we need one extra for trips and the NULL to terminate the array */
534         size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
535         /* This also takes care of API requirement to be NULL terminated */
536         groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
537         if (!groups)
538                 return -ENOMEM;
539
540         for (i = 0; i < size - 2; i++)
541                 groups[i] = thermal_zone_attribute_groups[i];
542
543         if (tz->trips) {
544                 result = create_trip_attrs(tz, mask);
545                 if (result) {
546                         kfree(groups);
547
548                         return result;
549                 }
550
551                 groups[size - 2] = &tz->trips_attribute_group;
552         }
553
554         tz->device.groups = groups;
555
556         return 0;
557 }
558
559 void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
560 {
561         if (!tz)
562                 return;
563
564         if (tz->trips)
565                 destroy_trip_attrs(tz);
566
567         kfree(tz->device.groups);
568 }
569
570 /* sys I/F for cooling device */
571 static ssize_t
572 cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
573 {
574         struct thermal_cooling_device *cdev = to_cooling_device(dev);
575
576         return sprintf(buf, "%s\n", cdev->type);
577 }
578
579 static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
580                               char *buf)
581 {
582         struct thermal_cooling_device *cdev = to_cooling_device(dev);
583         unsigned long state;
584         int ret;
585
586         ret = cdev->ops->get_max_state(cdev, &state);
587         if (ret)
588                 return ret;
589         return sprintf(buf, "%ld\n", state);
590 }
591
592 static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
593                               char *buf)
594 {
595         struct thermal_cooling_device *cdev = to_cooling_device(dev);
596         unsigned long state;
597         int ret;
598
599         ret = cdev->ops->get_cur_state(cdev, &state);
600         if (ret)
601                 return ret;
602         return sprintf(buf, "%ld\n", state);
603 }
604
605 static ssize_t
606 cur_state_store(struct device *dev, struct device_attribute *attr,
607                 const char *buf, size_t count)
608 {
609         struct thermal_cooling_device *cdev = to_cooling_device(dev);
610         unsigned long state;
611         int result;
612
613         dev_warn_once(&cdev->device,
614                       "Setting cooling device state is deprecated\n");
615         
616         if (sscanf(buf, "%ld\n", &state) != 1)
617                 return -EINVAL;
618
619         if ((long)state < 0)
620                 return -EINVAL;
621
622         mutex_lock(&cdev->lock);
623
624         result = cdev->ops->set_cur_state(cdev, state);
625         if (!result)
626                 thermal_cooling_device_stats_update(cdev, state);
627
628         mutex_unlock(&cdev->lock);
629         return result ? result : count;
630 }
631
632 static struct device_attribute
633 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
634 static DEVICE_ATTR_RO(max_state);
635 static DEVICE_ATTR_RW(cur_state);
636
637 static struct attribute *cooling_device_attrs[] = {
638         &dev_attr_cdev_type.attr,
639         &dev_attr_max_state.attr,
640         &dev_attr_cur_state.attr,
641         NULL,
642 };
643
644 static const struct attribute_group cooling_device_attr_group = {
645         .attrs = cooling_device_attrs,
646 };
647
648 static const struct attribute_group *cooling_device_attr_groups[] = {
649         &cooling_device_attr_group,
650         NULL, /* Space allocated for cooling_device_stats_attr_group */
651         NULL,
652 };
653
654 #ifdef CONFIG_THERMAL_STATISTICS
655 struct cooling_dev_stats {
656         spinlock_t lock;
657         unsigned int total_trans;
658         unsigned long state;
659         unsigned long max_states;
660         ktime_t last_time;
661         ktime_t *time_in_state;
662         unsigned int *trans_table;
663 };
664
665 static void update_time_in_state(struct cooling_dev_stats *stats)
666 {
667         ktime_t now = ktime_get(), delta;
668
669         delta = ktime_sub(now, stats->last_time);
670         stats->time_in_state[stats->state] =
671                 ktime_add(stats->time_in_state[stats->state], delta);
672         stats->last_time = now;
673 }
674
675 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
676                                          unsigned long new_state)
677 {
678         struct cooling_dev_stats *stats = cdev->stats;
679
680         if (!stats)
681                 return;
682
683         spin_lock(&stats->lock);
684
685         if (stats->state == new_state)
686                 goto unlock;
687
688         update_time_in_state(stats);
689         stats->trans_table[stats->state * stats->max_states + new_state]++;
690         stats->state = new_state;
691         stats->total_trans++;
692
693 unlock:
694         spin_unlock(&stats->lock);
695 }
696
697 static ssize_t total_trans_show(struct device *dev,
698                                 struct device_attribute *attr, char *buf)
699 {
700         struct thermal_cooling_device *cdev = to_cooling_device(dev);
701         struct cooling_dev_stats *stats = cdev->stats;
702         int ret;
703
704         spin_lock(&stats->lock);
705         ret = sprintf(buf, "%u\n", stats->total_trans);
706         spin_unlock(&stats->lock);
707
708         return ret;
709 }
710
711 static ssize_t
712 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
713                       char *buf)
714 {
715         struct thermal_cooling_device *cdev = to_cooling_device(dev);
716         struct cooling_dev_stats *stats = cdev->stats;
717         ssize_t len = 0;
718         int i;
719
720         spin_lock(&stats->lock);
721         update_time_in_state(stats);
722
723         for (i = 0; i < stats->max_states; i++) {
724                 len += sprintf(buf + len, "state%u\t%llu\n", i,
725                                ktime_to_ms(stats->time_in_state[i]));
726         }
727         spin_unlock(&stats->lock);
728
729         return len;
730 }
731
732 static ssize_t
733 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
734             size_t count)
735 {
736         struct thermal_cooling_device *cdev = to_cooling_device(dev);
737         struct cooling_dev_stats *stats = cdev->stats;
738         int i, states = stats->max_states;
739
740         spin_lock(&stats->lock);
741
742         stats->total_trans = 0;
743         stats->last_time = ktime_get();
744         memset(stats->trans_table, 0,
745                states * states * sizeof(*stats->trans_table));
746
747         for (i = 0; i < stats->max_states; i++)
748                 stats->time_in_state[i] = ktime_set(0, 0);
749
750         spin_unlock(&stats->lock);
751
752         return count;
753 }
754
755 static ssize_t trans_table_show(struct device *dev,
756                                 struct device_attribute *attr, char *buf)
757 {
758         struct thermal_cooling_device *cdev = to_cooling_device(dev);
759         struct cooling_dev_stats *stats = cdev->stats;
760         ssize_t len = 0;
761         int i, j;
762
763         len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
764         len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
765         for (i = 0; i < stats->max_states; i++) {
766                 if (len >= PAGE_SIZE)
767                         break;
768                 len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
769         }
770         if (len >= PAGE_SIZE)
771                 return PAGE_SIZE;
772
773         len += snprintf(buf + len, PAGE_SIZE - len, "\n");
774
775         for (i = 0; i < stats->max_states; i++) {
776                 if (len >= PAGE_SIZE)
777                         break;
778
779                 len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
780
781                 for (j = 0; j < stats->max_states; j++) {
782                         if (len >= PAGE_SIZE)
783                                 break;
784                         len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
785                                 stats->trans_table[i * stats->max_states + j]);
786                 }
787                 if (len >= PAGE_SIZE)
788                         break;
789                 len += snprintf(buf + len, PAGE_SIZE - len, "\n");
790         }
791
792         if (len >= PAGE_SIZE) {
793                 pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
794                 return -EFBIG;
795         }
796         return len;
797 }
798
799 static DEVICE_ATTR_RO(total_trans);
800 static DEVICE_ATTR_RO(time_in_state_ms);
801 static DEVICE_ATTR_WO(reset);
802 static DEVICE_ATTR_RO(trans_table);
803
804 static struct attribute *cooling_device_stats_attrs[] = {
805         &dev_attr_total_trans.attr,
806         &dev_attr_time_in_state_ms.attr,
807         &dev_attr_reset.attr,
808         &dev_attr_trans_table.attr,
809         NULL
810 };
811
812 static const struct attribute_group cooling_device_stats_attr_group = {
813         .attrs = cooling_device_stats_attrs,
814         .name = "stats"
815 };
816
817 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
818 {
819         struct cooling_dev_stats *stats;
820         unsigned long states;
821         int var;
822
823         if (cdev->ops->get_max_state(cdev, &states))
824                 return;
825
826         states++; /* Total number of states is highest state + 1 */
827
828         var = sizeof(*stats);
829         var += sizeof(*stats->time_in_state) * states;
830         var += sizeof(*stats->trans_table) * states * states;
831
832         stats = kzalloc(var, GFP_KERNEL);
833         if (!stats)
834                 return;
835
836         stats->time_in_state = (ktime_t *)(stats + 1);
837         stats->trans_table = (unsigned int *)(stats->time_in_state + states);
838         cdev->stats = stats;
839         stats->last_time = ktime_get();
840         stats->max_states = states;
841
842         spin_lock_init(&stats->lock);
843
844         /* Fill the empty slot left in cooling_device_attr_groups */
845         var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
846         cooling_device_attr_groups[var] = &cooling_device_stats_attr_group;
847 }
848
849 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
850 {
851         kfree(cdev->stats);
852         cdev->stats = NULL;
853 }
854
855 #else
856
857 static inline void
858 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
859 static inline void
860 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
861
862 #endif /* CONFIG_THERMAL_STATISTICS */
863
864 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
865 {
866         cooling_device_stats_setup(cdev);
867         cdev->device.groups = cooling_device_attr_groups;
868 }
869
870 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
871 {
872         cooling_device_stats_destroy(cdev);
873 }
874
875 /* these helper will be used only at the time of bindig */
876 ssize_t
877 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
878 {
879         struct thermal_instance *instance;
880
881         instance =
882             container_of(attr, struct thermal_instance, attr);
883
884         return sprintf(buf, "%d\n", instance->trip);
885 }
886
887 ssize_t
888 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
889 {
890         struct thermal_instance *instance;
891
892         instance = container_of(attr, struct thermal_instance, weight_attr);
893
894         return sprintf(buf, "%d\n", instance->weight);
895 }
896
897 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
898                      const char *buf, size_t count)
899 {
900         struct thermal_instance *instance;
901         int ret, weight;
902
903         ret = kstrtoint(buf, 0, &weight);
904         if (ret)
905                 return ret;
906
907         instance = container_of(attr, struct thermal_instance, weight_attr);
908         instance->weight = weight;
909
910         return count;
911 }