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 	if (sscanf(buf, "%ld\n", &state) != 1)
614 		return -EINVAL;
615 
616 	if ((long)state < 0)
617 		return -EINVAL;
618 
619 	mutex_lock(&cdev->lock);
620 
621 	result = cdev->ops->set_cur_state(cdev, state);
622 	if (!result)
623 		thermal_cooling_device_stats_update(cdev, state);
624 
625 	mutex_unlock(&cdev->lock);
626 	return result ? result : count;
627 }
628 
629 static struct device_attribute
630 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
631 static DEVICE_ATTR_RO(max_state);
632 static DEVICE_ATTR_RW(cur_state);
633 
634 static struct attribute *cooling_device_attrs[] = {
635 	&dev_attr_cdev_type.attr,
636 	&dev_attr_max_state.attr,
637 	&dev_attr_cur_state.attr,
638 	NULL,
639 };
640 
641 static const struct attribute_group cooling_device_attr_group = {
642 	.attrs = cooling_device_attrs,
643 };
644 
645 static const struct attribute_group *cooling_device_attr_groups[] = {
646 	&cooling_device_attr_group,
647 	NULL, /* Space allocated for cooling_device_stats_attr_group */
648 	NULL,
649 };
650 
651 #ifdef CONFIG_THERMAL_STATISTICS
652 struct cooling_dev_stats {
653 	spinlock_t lock;
654 	unsigned int total_trans;
655 	unsigned long state;
656 	unsigned long max_states;
657 	ktime_t last_time;
658 	ktime_t *time_in_state;
659 	unsigned int *trans_table;
660 };
661 
662 static void update_time_in_state(struct cooling_dev_stats *stats)
663 {
664 	ktime_t now = ktime_get(), delta;
665 
666 	delta = ktime_sub(now, stats->last_time);
667 	stats->time_in_state[stats->state] =
668 		ktime_add(stats->time_in_state[stats->state], delta);
669 	stats->last_time = now;
670 }
671 
672 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
673 					 unsigned long new_state)
674 {
675 	struct cooling_dev_stats *stats = cdev->stats;
676 
677 	if (!stats)
678 		return;
679 
680 	spin_lock(&stats->lock);
681 
682 	if (stats->state == new_state)
683 		goto unlock;
684 
685 	update_time_in_state(stats);
686 	stats->trans_table[stats->state * stats->max_states + new_state]++;
687 	stats->state = new_state;
688 	stats->total_trans++;
689 
690 unlock:
691 	spin_unlock(&stats->lock);
692 }
693 
694 static ssize_t total_trans_show(struct device *dev,
695 				struct device_attribute *attr, char *buf)
696 {
697 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
698 	struct cooling_dev_stats *stats = cdev->stats;
699 	int ret;
700 
701 	spin_lock(&stats->lock);
702 	ret = sprintf(buf, "%u\n", stats->total_trans);
703 	spin_unlock(&stats->lock);
704 
705 	return ret;
706 }
707 
708 static ssize_t
709 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
710 		      char *buf)
711 {
712 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
713 	struct cooling_dev_stats *stats = cdev->stats;
714 	ssize_t len = 0;
715 	int i;
716 
717 	spin_lock(&stats->lock);
718 	update_time_in_state(stats);
719 
720 	for (i = 0; i < stats->max_states; i++) {
721 		len += sprintf(buf + len, "state%u\t%llu\n", i,
722 			       ktime_to_ms(stats->time_in_state[i]));
723 	}
724 	spin_unlock(&stats->lock);
725 
726 	return len;
727 }
728 
729 static ssize_t
730 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
731 	    size_t count)
732 {
733 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
734 	struct cooling_dev_stats *stats = cdev->stats;
735 	int i, states = stats->max_states;
736 
737 	spin_lock(&stats->lock);
738 
739 	stats->total_trans = 0;
740 	stats->last_time = ktime_get();
741 	memset(stats->trans_table, 0,
742 	       states * states * sizeof(*stats->trans_table));
743 
744 	for (i = 0; i < stats->max_states; i++)
745 		stats->time_in_state[i] = ktime_set(0, 0);
746 
747 	spin_unlock(&stats->lock);
748 
749 	return count;
750 }
751 
752 static ssize_t trans_table_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 	ssize_t len = 0;
758 	int i, j;
759 
760 	len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
761 	len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
762 	for (i = 0; i < stats->max_states; i++) {
763 		if (len >= PAGE_SIZE)
764 			break;
765 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
766 	}
767 	if (len >= PAGE_SIZE)
768 		return PAGE_SIZE;
769 
770 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
771 
772 	for (i = 0; i < stats->max_states; i++) {
773 		if (len >= PAGE_SIZE)
774 			break;
775 
776 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
777 
778 		for (j = 0; j < stats->max_states; j++) {
779 			if (len >= PAGE_SIZE)
780 				break;
781 			len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
782 				stats->trans_table[i * stats->max_states + j]);
783 		}
784 		if (len >= PAGE_SIZE)
785 			break;
786 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
787 	}
788 
789 	if (len >= PAGE_SIZE) {
790 		pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
791 		return -EFBIG;
792 	}
793 	return len;
794 }
795 
796 static DEVICE_ATTR_RO(total_trans);
797 static DEVICE_ATTR_RO(time_in_state_ms);
798 static DEVICE_ATTR_WO(reset);
799 static DEVICE_ATTR_RO(trans_table);
800 
801 static struct attribute *cooling_device_stats_attrs[] = {
802 	&dev_attr_total_trans.attr,
803 	&dev_attr_time_in_state_ms.attr,
804 	&dev_attr_reset.attr,
805 	&dev_attr_trans_table.attr,
806 	NULL
807 };
808 
809 static const struct attribute_group cooling_device_stats_attr_group = {
810 	.attrs = cooling_device_stats_attrs,
811 	.name = "stats"
812 };
813 
814 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
815 {
816 	struct cooling_dev_stats *stats;
817 	unsigned long states;
818 	int var;
819 
820 	if (cdev->ops->get_max_state(cdev, &states))
821 		return;
822 
823 	states++; /* Total number of states is highest state + 1 */
824 
825 	var = sizeof(*stats);
826 	var += sizeof(*stats->time_in_state) * states;
827 	var += sizeof(*stats->trans_table) * states * states;
828 
829 	stats = kzalloc(var, GFP_KERNEL);
830 	if (!stats)
831 		return;
832 
833 	stats->time_in_state = (ktime_t *)(stats + 1);
834 	stats->trans_table = (unsigned int *)(stats->time_in_state + states);
835 	cdev->stats = stats;
836 	stats->last_time = ktime_get();
837 	stats->max_states = states;
838 
839 	spin_lock_init(&stats->lock);
840 
841 	/* Fill the empty slot left in cooling_device_attr_groups */
842 	var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
843 	cooling_device_attr_groups[var] = &cooling_device_stats_attr_group;
844 }
845 
846 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
847 {
848 	kfree(cdev->stats);
849 	cdev->stats = NULL;
850 }
851 
852 #else
853 
854 static inline void
855 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
856 static inline void
857 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
858 
859 #endif /* CONFIG_THERMAL_STATISTICS */
860 
861 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
862 {
863 	cooling_device_stats_setup(cdev);
864 	cdev->device.groups = cooling_device_attr_groups;
865 }
866 
867 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
868 {
869 	cooling_device_stats_destroy(cdev);
870 }
871 
872 /* these helper will be used only at the time of bindig */
873 ssize_t
874 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
875 {
876 	struct thermal_instance *instance;
877 
878 	instance =
879 	    container_of(attr, struct thermal_instance, attr);
880 
881 	return sprintf(buf, "%d\n", instance->trip);
882 }
883 
884 ssize_t
885 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
886 {
887 	struct thermal_instance *instance;
888 
889 	instance = container_of(attr, struct thermal_instance, weight_attr);
890 
891 	return sprintf(buf, "%d\n", instance->weight);
892 }
893 
894 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
895 		     const char *buf, size_t count)
896 {
897 	struct thermal_instance *instance;
898 	int ret, weight;
899 
900 	ret = kstrtoint(buf, 0, &weight);
901 	if (ret)
902 		return ret;
903 
904 	instance = container_of(attr, struct thermal_instance, weight_attr);
905 	instance->weight = weight;
906 
907 	return count;
908 }
909