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