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
26static ssize_t
27type_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
34static ssize_t
35temp_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
48static ssize_t
49mode_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
61static ssize_t
62mode_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
81static ssize_t
82trip_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	struct thermal_trip trip;
87	int trip_id, result;
88
89	if (sscanf(attr->attr.name, "trip_point_%d_type", &trip_id) != 1)
90		return -EINVAL;
91
92	mutex_lock(&tz->lock);
93
94	if (device_is_registered(dev))
95		result = __thermal_zone_get_trip(tz, trip_id, &trip);
96	else
97		result = -ENODEV;
98
99	mutex_unlock(&tz->lock);
100
101	if (result)
102		return result;
103
104	switch (trip.type) {
105	case THERMAL_TRIP_CRITICAL:
106		return sprintf(buf, "critical\n");
107	case THERMAL_TRIP_HOT:
108		return sprintf(buf, "hot\n");
109	case THERMAL_TRIP_PASSIVE:
110		return sprintf(buf, "passive\n");
111	case THERMAL_TRIP_ACTIVE:
112		return sprintf(buf, "active\n");
113	default:
114		return sprintf(buf, "unknown\n");
115	}
116}
117
118static ssize_t
119trip_point_temp_store(struct device *dev, struct device_attribute *attr,
120		      const char *buf, size_t count)
121{
122	struct thermal_zone_device *tz = to_thermal_zone(dev);
123	struct thermal_trip trip;
124	int trip_id, ret;
125
126	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
127		return -EINVAL;
128
129	mutex_lock(&tz->lock);
130
131	if (!device_is_registered(dev)) {
132		ret = -ENODEV;
133		goto unlock;
134	}
135
136	ret = __thermal_zone_get_trip(tz, trip_id, &trip);
137	if (ret)
138		goto unlock;
139
140	ret = kstrtoint(buf, 10, &trip.temperature);
141	if (ret)
142		goto unlock;
143
144	ret = thermal_zone_set_trip(tz, trip_id, &trip);
145unlock:
146	mutex_unlock(&tz->lock);
147
148	return ret ? ret : count;
149}
150
151static ssize_t
152trip_point_temp_show(struct device *dev, struct device_attribute *attr,
153		     char *buf)
154{
155	struct thermal_zone_device *tz = to_thermal_zone(dev);
156	struct thermal_trip trip;
157	int trip_id, ret;
158
159	if (sscanf(attr->attr.name, "trip_point_%d_temp", &trip_id) != 1)
160		return -EINVAL;
161
162	mutex_lock(&tz->lock);
163
164	if (device_is_registered(dev))
165		ret = __thermal_zone_get_trip(tz, trip_id, &trip);
166	else
167		ret = -ENODEV;
168
169	mutex_unlock(&tz->lock);
170
171	if (ret)
172		return ret;
173
174	return sprintf(buf, "%d\n", trip.temperature);
175}
176
177static ssize_t
178trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
179		      const char *buf, size_t count)
180{
181	struct thermal_zone_device *tz = to_thermal_zone(dev);
182	struct thermal_trip trip;
183	int trip_id, ret;
184
185	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
186		return -EINVAL;
187
188	mutex_lock(&tz->lock);
189
190	if (!device_is_registered(dev)) {
191		ret = -ENODEV;
192		goto unlock;
193	}
194
195	ret = __thermal_zone_get_trip(tz, trip_id, &trip);
196	if (ret)
197		goto unlock;
198
199	ret = kstrtoint(buf, 10, &trip.hysteresis);
200	if (ret)
201		goto unlock;
202
203	ret = thermal_zone_set_trip(tz, trip_id, &trip);
204unlock:
205	mutex_unlock(&tz->lock);
206
207	return ret ? ret : count;
208}
209
210static ssize_t
211trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
212		     char *buf)
213{
214	struct thermal_zone_device *tz = to_thermal_zone(dev);
215	struct thermal_trip trip;
216	int trip_id, ret;
217
218	if (sscanf(attr->attr.name, "trip_point_%d_hyst", &trip_id) != 1)
219		return -EINVAL;
220
221	mutex_lock(&tz->lock);
222
223	if (device_is_registered(dev))
224		ret = __thermal_zone_get_trip(tz, trip_id, &trip);
225	else
226		ret = -ENODEV;
227
228	mutex_unlock(&tz->lock);
229
230	return ret ? ret : sprintf(buf, "%d\n", trip.hysteresis);
231}
232
233static ssize_t
234policy_store(struct device *dev, struct device_attribute *attr,
235	     const char *buf, size_t count)
236{
237	struct thermal_zone_device *tz = to_thermal_zone(dev);
238	char name[THERMAL_NAME_LENGTH];
239	int ret;
240
241	snprintf(name, sizeof(name), "%s", buf);
242
243	ret = thermal_zone_device_set_policy(tz, name);
244	if (!ret)
245		ret = count;
246
247	return ret;
248}
249
250static ssize_t
251policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
252{
253	struct thermal_zone_device *tz = to_thermal_zone(dev);
254
255	return sprintf(buf, "%s\n", tz->governor->name);
256}
257
258static ssize_t
259available_policies_show(struct device *dev, struct device_attribute *devattr,
260			char *buf)
261{
262	return thermal_build_list_of_policies(buf);
263}
264
265#if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
266static ssize_t
267emul_temp_store(struct device *dev, struct device_attribute *attr,
268		const char *buf, size_t count)
269{
270	struct thermal_zone_device *tz = to_thermal_zone(dev);
271	int ret = 0;
272	int temperature;
273
274	if (kstrtoint(buf, 10, &temperature))
275		return -EINVAL;
276
277	mutex_lock(&tz->lock);
278
279	if (!device_is_registered(dev)) {
280		ret = -ENODEV;
281		goto unlock;
282	}
283
284	if (!tz->ops->set_emul_temp)
285		tz->emul_temperature = temperature;
286	else
287		ret = tz->ops->set_emul_temp(tz, temperature);
288
289	if (!ret)
290		__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
291
292unlock:
293	mutex_unlock(&tz->lock);
294
295	return ret ? ret : count;
296}
297static DEVICE_ATTR_WO(emul_temp);
298#endif
299
300static ssize_t
301sustainable_power_show(struct device *dev, struct device_attribute *devattr,
302		       char *buf)
303{
304	struct thermal_zone_device *tz = to_thermal_zone(dev);
305
306	if (tz->tzp)
307		return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
308	else
309		return -EIO;
310}
311
312static ssize_t
313sustainable_power_store(struct device *dev, struct device_attribute *devattr,
314			const char *buf, size_t count)
315{
316	struct thermal_zone_device *tz = to_thermal_zone(dev);
317	u32 sustainable_power;
318
319	if (!tz->tzp)
320		return -EIO;
321
322	if (kstrtou32(buf, 10, &sustainable_power))
323		return -EINVAL;
324
325	tz->tzp->sustainable_power = sustainable_power;
326
327	return count;
328}
329
330#define create_s32_tzp_attr(name)					\
331	static ssize_t							\
332	name##_show(struct device *dev, struct device_attribute *devattr, \
333		char *buf)						\
334	{								\
335	struct thermal_zone_device *tz = to_thermal_zone(dev);		\
336									\
337	if (tz->tzp)							\
338		return sprintf(buf, "%d\n", tz->tzp->name);		\
339	else								\
340		return -EIO;						\
341	}								\
342									\
343	static ssize_t							\
344	name##_store(struct device *dev, struct device_attribute *devattr, \
345		const char *buf, size_t count)				\
346	{								\
347		struct thermal_zone_device *tz = to_thermal_zone(dev);	\
348		s32 value;						\
349									\
350		if (!tz->tzp)						\
351			return -EIO;					\
352									\
353		if (kstrtos32(buf, 10, &value))				\
354			return -EINVAL;					\
355									\
356		tz->tzp->name = value;					\
357									\
358		return count;						\
359	}								\
360	static DEVICE_ATTR_RW(name)
361
362create_s32_tzp_attr(k_po);
363create_s32_tzp_attr(k_pu);
364create_s32_tzp_attr(k_i);
365create_s32_tzp_attr(k_d);
366create_s32_tzp_attr(integral_cutoff);
367create_s32_tzp_attr(slope);
368create_s32_tzp_attr(offset);
369#undef create_s32_tzp_attr
370
371/*
372 * These are thermal zone device attributes that will always be present.
373 * All the attributes created for tzp (create_s32_tzp_attr) also are always
374 * present on the sysfs interface.
375 */
376static DEVICE_ATTR_RO(type);
377static DEVICE_ATTR_RO(temp);
378static DEVICE_ATTR_RW(policy);
379static DEVICE_ATTR_RO(available_policies);
380static DEVICE_ATTR_RW(sustainable_power);
381
382/* These thermal zone device attributes are created based on conditions */
383static DEVICE_ATTR_RW(mode);
384
385/* These attributes are unconditionally added to a thermal zone */
386static struct attribute *thermal_zone_dev_attrs[] = {
387	&dev_attr_type.attr,
388	&dev_attr_temp.attr,
389#if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
390	&dev_attr_emul_temp.attr,
391#endif
392	&dev_attr_policy.attr,
393	&dev_attr_available_policies.attr,
394	&dev_attr_sustainable_power.attr,
395	&dev_attr_k_po.attr,
396	&dev_attr_k_pu.attr,
397	&dev_attr_k_i.attr,
398	&dev_attr_k_d.attr,
399	&dev_attr_integral_cutoff.attr,
400	&dev_attr_slope.attr,
401	&dev_attr_offset.attr,
402	NULL,
403};
404
405static const struct attribute_group thermal_zone_attribute_group = {
406	.attrs = thermal_zone_dev_attrs,
407};
408
409static struct attribute *thermal_zone_mode_attrs[] = {
410	&dev_attr_mode.attr,
411	NULL,
412};
413
414static const struct attribute_group thermal_zone_mode_attribute_group = {
415	.attrs = thermal_zone_mode_attrs,
416};
417
418static const struct attribute_group *thermal_zone_attribute_groups[] = {
419	&thermal_zone_attribute_group,
420	&thermal_zone_mode_attribute_group,
421	/* This is not NULL terminated as we create the group dynamically */
422};
423
424/**
425 * create_trip_attrs() - create attributes for trip points
426 * @tz:		the thermal zone device
427 * @mask:	Writeable trip point bitmap.
428 *
429 * helper function to instantiate sysfs entries for every trip
430 * point and its properties of a struct thermal_zone_device.
431 *
432 * Return: 0 on success, the proper error value otherwise.
433 */
434static int create_trip_attrs(struct thermal_zone_device *tz, int mask)
435{
436	struct attribute **attrs;
437	int indx;
438
439	/* This function works only for zones with at least one trip */
440	if (tz->num_trips <= 0)
441		return -EINVAL;
442
443	tz->trip_type_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_type_attrs),
444				      GFP_KERNEL);
445	if (!tz->trip_type_attrs)
446		return -ENOMEM;
447
448	tz->trip_temp_attrs = kcalloc(tz->num_trips, sizeof(*tz->trip_temp_attrs),
449				      GFP_KERNEL);
450	if (!tz->trip_temp_attrs) {
451		kfree(tz->trip_type_attrs);
452		return -ENOMEM;
453	}
454
455	tz->trip_hyst_attrs = kcalloc(tz->num_trips,
456				      sizeof(*tz->trip_hyst_attrs),
457				      GFP_KERNEL);
458	if (!tz->trip_hyst_attrs) {
459		kfree(tz->trip_type_attrs);
460		kfree(tz->trip_temp_attrs);
461		return -ENOMEM;
462	}
463
464	attrs = kcalloc(tz->num_trips * 3 + 1, sizeof(*attrs), GFP_KERNEL);
465	if (!attrs) {
466		kfree(tz->trip_type_attrs);
467		kfree(tz->trip_temp_attrs);
468		kfree(tz->trip_hyst_attrs);
469		return -ENOMEM;
470	}
471
472	for (indx = 0; indx < tz->num_trips; indx++) {
473		/* create trip type attribute */
474		snprintf(tz->trip_type_attrs[indx].name, THERMAL_NAME_LENGTH,
475			 "trip_point_%d_type", indx);
476
477		sysfs_attr_init(&tz->trip_type_attrs[indx].attr.attr);
478		tz->trip_type_attrs[indx].attr.attr.name =
479						tz->trip_type_attrs[indx].name;
480		tz->trip_type_attrs[indx].attr.attr.mode = S_IRUGO;
481		tz->trip_type_attrs[indx].attr.show = trip_point_type_show;
482		attrs[indx] = &tz->trip_type_attrs[indx].attr.attr;
483
484		/* create trip temp attribute */
485		snprintf(tz->trip_temp_attrs[indx].name, THERMAL_NAME_LENGTH,
486			 "trip_point_%d_temp", indx);
487
488		sysfs_attr_init(&tz->trip_temp_attrs[indx].attr.attr);
489		tz->trip_temp_attrs[indx].attr.attr.name =
490						tz->trip_temp_attrs[indx].name;
491		tz->trip_temp_attrs[indx].attr.attr.mode = S_IRUGO;
492		tz->trip_temp_attrs[indx].attr.show = trip_point_temp_show;
493		if (IS_ENABLED(CONFIG_THERMAL_WRITABLE_TRIPS) &&
494		    mask & (1 << indx)) {
495			tz->trip_temp_attrs[indx].attr.attr.mode |= S_IWUSR;
496			tz->trip_temp_attrs[indx].attr.store =
497							trip_point_temp_store;
498		}
499		attrs[indx + tz->num_trips] = &tz->trip_temp_attrs[indx].attr.attr;
500
501		snprintf(tz->trip_hyst_attrs[indx].name, THERMAL_NAME_LENGTH,
502			 "trip_point_%d_hyst", indx);
503
504		sysfs_attr_init(&tz->trip_hyst_attrs[indx].attr.attr);
505		tz->trip_hyst_attrs[indx].attr.attr.name =
506					tz->trip_hyst_attrs[indx].name;
507		tz->trip_hyst_attrs[indx].attr.attr.mode = S_IRUGO;
508		tz->trip_hyst_attrs[indx].attr.show = trip_point_hyst_show;
509		if (tz->ops->set_trip_hyst) {
510			tz->trip_hyst_attrs[indx].attr.attr.mode |= S_IWUSR;
511			tz->trip_hyst_attrs[indx].attr.store =
512					trip_point_hyst_store;
513		}
514		attrs[indx + tz->num_trips * 2] =
515					&tz->trip_hyst_attrs[indx].attr.attr;
516	}
517	attrs[tz->num_trips * 3] = NULL;
518
519	tz->trips_attribute_group.attrs = attrs;
520
521	return 0;
522}
523
524/**
525 * destroy_trip_attrs() - destroy attributes for trip points
526 * @tz:		the thermal zone device
527 *
528 * helper function to free resources allocated by create_trip_attrs()
529 */
530static void destroy_trip_attrs(struct thermal_zone_device *tz)
531{
532	if (!tz)
533		return;
534
535	kfree(tz->trip_type_attrs);
536	kfree(tz->trip_temp_attrs);
537	kfree(tz->trip_hyst_attrs);
538	kfree(tz->trips_attribute_group.attrs);
539}
540
541int thermal_zone_create_device_groups(struct thermal_zone_device *tz,
542				      int mask)
543{
544	const struct attribute_group **groups;
545	int i, size, result;
546
547	/* we need one extra for trips and the NULL to terminate the array */
548	size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
549	/* This also takes care of API requirement to be NULL terminated */
550	groups = kcalloc(size, sizeof(*groups), GFP_KERNEL);
551	if (!groups)
552		return -ENOMEM;
553
554	for (i = 0; i < size - 2; i++)
555		groups[i] = thermal_zone_attribute_groups[i];
556
557	if (tz->num_trips) {
558		result = create_trip_attrs(tz, mask);
559		if (result) {
560			kfree(groups);
561
562			return result;
563		}
564
565		groups[size - 2] = &tz->trips_attribute_group;
566	}
567
568	tz->device.groups = groups;
569
570	return 0;
571}
572
573void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
574{
575	if (!tz)
576		return;
577
578	if (tz->num_trips)
579		destroy_trip_attrs(tz);
580
581	kfree(tz->device.groups);
582}
583
584/* sys I/F for cooling device */
585static ssize_t
586cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
587{
588	struct thermal_cooling_device *cdev = to_cooling_device(dev);
589
590	return sprintf(buf, "%s\n", cdev->type);
591}
592
593static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
594			      char *buf)
595{
596	struct thermal_cooling_device *cdev = to_cooling_device(dev);
597
598	return sprintf(buf, "%ld\n", cdev->max_state);
599}
600
601static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
602			      char *buf)
603{
604	struct thermal_cooling_device *cdev = to_cooling_device(dev);
605	unsigned long state;
606	int ret;
607
608	ret = cdev->ops->get_cur_state(cdev, &state);
609	if (ret)
610		return ret;
611	return sprintf(buf, "%ld\n", state);
612}
613
614static ssize_t
615cur_state_store(struct device *dev, struct device_attribute *attr,
616		const char *buf, size_t count)
617{
618	struct thermal_cooling_device *cdev = to_cooling_device(dev);
619	unsigned long state;
620	int result;
621
622	if (sscanf(buf, "%ld\n", &state) != 1)
623		return -EINVAL;
624
625	if ((long)state < 0)
626		return -EINVAL;
627
628	/* Requested state should be less than max_state + 1 */
629	if (state > cdev->max_state)
630		return -EINVAL;
631
632	mutex_lock(&cdev->lock);
633
634	result = cdev->ops->set_cur_state(cdev, state);
635	if (!result)
636		thermal_cooling_device_stats_update(cdev, state);
637
638	mutex_unlock(&cdev->lock);
639	return result ? result : count;
640}
641
642static struct device_attribute
643dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
644static DEVICE_ATTR_RO(max_state);
645static DEVICE_ATTR_RW(cur_state);
646
647static struct attribute *cooling_device_attrs[] = {
648	&dev_attr_cdev_type.attr,
649	&dev_attr_max_state.attr,
650	&dev_attr_cur_state.attr,
651	NULL,
652};
653
654static const struct attribute_group cooling_device_attr_group = {
655	.attrs = cooling_device_attrs,
656};
657
658static const struct attribute_group *cooling_device_attr_groups[] = {
659	&cooling_device_attr_group,
660	NULL, /* Space allocated for cooling_device_stats_attr_group */
661	NULL,
662};
663
664#ifdef CONFIG_THERMAL_STATISTICS
665struct cooling_dev_stats {
666	spinlock_t lock;
667	unsigned int total_trans;
668	unsigned long state;
669	ktime_t last_time;
670	ktime_t *time_in_state;
671	unsigned int *trans_table;
672};
673
674static void update_time_in_state(struct cooling_dev_stats *stats)
675{
676	ktime_t now = ktime_get(), delta;
677
678	delta = ktime_sub(now, stats->last_time);
679	stats->time_in_state[stats->state] =
680		ktime_add(stats->time_in_state[stats->state], delta);
681	stats->last_time = now;
682}
683
684void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
685					 unsigned long new_state)
686{
687	struct cooling_dev_stats *stats = cdev->stats;
688
689	lockdep_assert_held(&cdev->lock);
690
691	if (!stats)
692		return;
693
694	spin_lock(&stats->lock);
695
696	if (stats->state == new_state)
697		goto unlock;
698
699	update_time_in_state(stats);
700	stats->trans_table[stats->state * (cdev->max_state + 1) + new_state]++;
701	stats->state = new_state;
702	stats->total_trans++;
703
704unlock:
705	spin_unlock(&stats->lock);
706}
707
708static ssize_t total_trans_show(struct device *dev,
709				struct device_attribute *attr, char *buf)
710{
711	struct thermal_cooling_device *cdev = to_cooling_device(dev);
712	struct cooling_dev_stats *stats;
713	int ret = 0;
714
715	mutex_lock(&cdev->lock);
716
717	stats = cdev->stats;
718	if (!stats)
719		goto unlock;
720
721	spin_lock(&stats->lock);
722	ret = sprintf(buf, "%u\n", stats->total_trans);
723	spin_unlock(&stats->lock);
724
725unlock:
726	mutex_unlock(&cdev->lock);
727
728	return ret;
729}
730
731static ssize_t
732time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
733		      char *buf)
734{
735	struct thermal_cooling_device *cdev = to_cooling_device(dev);
736	struct cooling_dev_stats *stats;
737	ssize_t len = 0;
738	int i;
739
740	mutex_lock(&cdev->lock);
741
742	stats = cdev->stats;
743	if (!stats)
744		goto unlock;
745
746	spin_lock(&stats->lock);
747
748	update_time_in_state(stats);
749
750	for (i = 0; i <= cdev->max_state; i++) {
751		len += sprintf(buf + len, "state%u\t%llu\n", i,
752			       ktime_to_ms(stats->time_in_state[i]));
753	}
754	spin_unlock(&stats->lock);
755
756unlock:
757	mutex_unlock(&cdev->lock);
758
759	return len;
760}
761
762static ssize_t
763reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
764	    size_t count)
765{
766	struct thermal_cooling_device *cdev = to_cooling_device(dev);
767	struct cooling_dev_stats *stats;
768	int i, states;
769
770	mutex_lock(&cdev->lock);
771
772	stats = cdev->stats;
773	if (!stats)
774		goto unlock;
775
776	states = cdev->max_state + 1;
777
778	spin_lock(&stats->lock);
779
780	stats->total_trans = 0;
781	stats->last_time = ktime_get();
782	memset(stats->trans_table, 0,
783	       states * states * sizeof(*stats->trans_table));
784
785	for (i = 0; i < states; i++)
786		stats->time_in_state[i] = ktime_set(0, 0);
787
788	spin_unlock(&stats->lock);
789
790unlock:
791	mutex_unlock(&cdev->lock);
792
793	return count;
794}
795
796static ssize_t trans_table_show(struct device *dev,
797				struct device_attribute *attr, char *buf)
798{
799	struct thermal_cooling_device *cdev = to_cooling_device(dev);
800	struct cooling_dev_stats *stats;
801	ssize_t len = 0;
802	int i, j;
803
804	mutex_lock(&cdev->lock);
805
806	stats = cdev->stats;
807	if (!stats) {
808		len = -ENODATA;
809		goto unlock;
810	}
811
812	len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
813	len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
814	for (i = 0; i <= cdev->max_state; i++) {
815		if (len >= PAGE_SIZE)
816			break;
817		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
818	}
819	if (len >= PAGE_SIZE) {
820		len = PAGE_SIZE;
821		goto unlock;
822	}
823
824	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
825
826	for (i = 0; i <= cdev->max_state; i++) {
827		if (len >= PAGE_SIZE)
828			break;
829
830		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
831
832		for (j = 0; j <= cdev->max_state; j++) {
833			if (len >= PAGE_SIZE)
834				break;
835			len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
836				stats->trans_table[i * (cdev->max_state + 1) + j]);
837		}
838		if (len >= PAGE_SIZE)
839			break;
840		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
841	}
842
843	if (len >= PAGE_SIZE) {
844		pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
845		len = -EFBIG;
846	}
847
848unlock:
849	mutex_unlock(&cdev->lock);
850
851	return len;
852}
853
854static DEVICE_ATTR_RO(total_trans);
855static DEVICE_ATTR_RO(time_in_state_ms);
856static DEVICE_ATTR_WO(reset);
857static DEVICE_ATTR_RO(trans_table);
858
859static struct attribute *cooling_device_stats_attrs[] = {
860	&dev_attr_total_trans.attr,
861	&dev_attr_time_in_state_ms.attr,
862	&dev_attr_reset.attr,
863	&dev_attr_trans_table.attr,
864	NULL
865};
866
867static const struct attribute_group cooling_device_stats_attr_group = {
868	.attrs = cooling_device_stats_attrs,
869	.name = "stats"
870};
871
872static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
873{
874	const struct attribute_group *stats_attr_group = NULL;
875	struct cooling_dev_stats *stats;
876	/* Total number of states is highest state + 1 */
877	unsigned long states = cdev->max_state + 1;
878	int var;
879
880	var = sizeof(*stats);
881	var += sizeof(*stats->time_in_state) * states;
882	var += sizeof(*stats->trans_table) * states * states;
883
884	stats = kzalloc(var, GFP_KERNEL);
885	if (!stats)
886		goto out;
887
888	stats->time_in_state = (ktime_t *)(stats + 1);
889	stats->trans_table = (unsigned int *)(stats->time_in_state + states);
890	cdev->stats = stats;
891	stats->last_time = ktime_get();
892
893	spin_lock_init(&stats->lock);
894
895	stats_attr_group = &cooling_device_stats_attr_group;
896
897out:
898	/* Fill the empty slot left in cooling_device_attr_groups */
899	var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
900	cooling_device_attr_groups[var] = stats_attr_group;
901}
902
903static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
904{
905	kfree(cdev->stats);
906	cdev->stats = NULL;
907}
908
909#else
910
911static inline void
912cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
913static inline void
914cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
915
916#endif /* CONFIG_THERMAL_STATISTICS */
917
918void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
919{
920	cooling_device_stats_setup(cdev);
921	cdev->device.groups = cooling_device_attr_groups;
922}
923
924void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
925{
926	cooling_device_stats_destroy(cdev);
927}
928
929void thermal_cooling_device_stats_reinit(struct thermal_cooling_device *cdev)
930{
931	lockdep_assert_held(&cdev->lock);
932
933	cooling_device_stats_destroy(cdev);
934	cooling_device_stats_setup(cdev);
935}
936
937/* these helper will be used only at the time of bindig */
938ssize_t
939trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
940{
941	struct thermal_instance *instance;
942
943	instance =
944	    container_of(attr, struct thermal_instance, attr);
945
946	return sprintf(buf, "%d\n",
947		       thermal_zone_trip_id(instance->tz, instance->trip));
948}
949
950ssize_t
951weight_show(struct device *dev, struct device_attribute *attr, char *buf)
952{
953	struct thermal_instance *instance;
954
955	instance = container_of(attr, struct thermal_instance, weight_attr);
956
957	return sprintf(buf, "%d\n", instance->weight);
958}
959
960ssize_t weight_store(struct device *dev, struct device_attribute *attr,
961		     const char *buf, size_t count)
962{
963	struct thermal_instance *instance;
964	int ret, weight;
965
966	ret = kstrtoint(buf, 0, &weight);
967	if (ret)
968		return ret;
969
970	instance = container_of(attr, struct thermal_instance, weight_attr);
971	instance->weight = weight;
972
973	return count;
974}
975