xref: /linux/drivers/thermal/thermal_sysfs.c (revision fbfb6bd927c9ac6ea155471cc7ced8e16b37c2cb)
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/container_of.h>
16 #include <linux/sysfs.h>
17 #include <linux/device.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/string.h>
21 #include <linux/string_choices.h>
22 #include <linux/jiffies.h>
23 
24 #include "thermal_core.h"
25 
26 /* sys I/F for thermal zone */
27 
28 static ssize_t
type_show(struct device * dev,struct device_attribute * attr,char * buf)29 type_show(struct device *dev, struct device_attribute *attr, char *buf)
30 {
31 	struct thermal_zone_device *tz = to_thermal_zone(dev);
32 
33 	return sysfs_emit(buf, "%s\n", tz->type);
34 }
35 
36 static ssize_t
temp_show(struct device * dev,struct device_attribute * attr,char * buf)37 temp_show(struct device *dev, struct device_attribute *attr, char *buf)
38 {
39 	struct thermal_zone_device *tz = to_thermal_zone(dev);
40 	int temperature, ret;
41 
42 	ret = thermal_zone_get_temp(tz, &temperature);
43 
44 	if (!ret)
45 		return sysfs_emit(buf, "%d\n", temperature);
46 
47 	if (ret == -EAGAIN)
48 		return -ENODATA;
49 
50 	return ret;
51 }
52 
53 static ssize_t
mode_show(struct device * dev,struct device_attribute * attr,char * buf)54 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
55 {
56 	struct thermal_zone_device *tz = to_thermal_zone(dev);
57 
58 	guard(thermal_zone)(tz);
59 
60 	return sysfs_emit(buf, "%s\n",
61 		str_enabled_disabled(tz->mode == THERMAL_DEVICE_ENABLED));
62 }
63 
64 static ssize_t
mode_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)65 mode_store(struct device *dev, struct device_attribute *attr,
66 	   const char *buf, size_t count)
67 {
68 	struct thermal_zone_device *tz = to_thermal_zone(dev);
69 	int result;
70 
71 	if (!strncmp(buf, "enabled", sizeof("enabled") - 1))
72 		result = thermal_zone_device_enable(tz);
73 	else if (!strncmp(buf, "disabled", sizeof("disabled") - 1))
74 		result = thermal_zone_device_disable(tz);
75 	else
76 		result = -EINVAL;
77 
78 	if (result)
79 		return result;
80 
81 	return count;
82 }
83 
84 #define thermal_trip_of_attr(_ptr_, _attr_)				\
85 	({ 								\
86 		struct thermal_trip_desc *td;				\
87 									\
88 		td = container_of(_ptr_, struct thermal_trip_desc,	\
89 				  trip_attrs._attr_.attr);		\
90 		&td->trip;						\
91 	})
92 
93 static ssize_t
trip_point_type_show(struct device * dev,struct device_attribute * attr,char * buf)94 trip_point_type_show(struct device *dev, struct device_attribute *attr,
95 		     char *buf)
96 {
97 	struct thermal_trip *trip = thermal_trip_of_attr(attr, type);
98 
99 	return sysfs_emit(buf, "%s\n", thermal_trip_type_name(trip->type));
100 }
101 
102 static ssize_t
trip_point_temp_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)103 trip_point_temp_store(struct device *dev, struct device_attribute *attr,
104 		      const char *buf, size_t count)
105 {
106 	struct thermal_trip *trip = thermal_trip_of_attr(attr, temp);
107 	struct thermal_zone_device *tz = to_thermal_zone(dev);
108 	int temp;
109 
110 	if (kstrtoint(buf, 10, &temp))
111 		return -EINVAL;
112 
113 	guard(thermal_zone)(tz);
114 
115 	if (temp == trip->temperature)
116 		return count;
117 
118 	/* Arrange the condition to avoid integer overflows. */
119 	if (temp != THERMAL_TEMP_INVALID &&
120 	    temp <= trip->hysteresis + THERMAL_TEMP_INVALID)
121 		return -EINVAL;
122 
123 	if (tz->ops.set_trip_temp) {
124 		int ret;
125 
126 		ret = tz->ops.set_trip_temp(tz, trip, temp);
127 		if (ret)
128 			return ret;
129 	}
130 
131 	thermal_zone_set_trip_temp(tz, trip, temp);
132 
133 	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
134 
135 	return count;
136 }
137 
138 static ssize_t
trip_point_temp_show(struct device * dev,struct device_attribute * attr,char * buf)139 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
140 		     char *buf)
141 {
142 	struct thermal_trip *trip = thermal_trip_of_attr(attr, temp);
143 
144 	return sysfs_emit(buf, "%d\n", READ_ONCE(trip->temperature));
145 }
146 
147 static ssize_t
trip_point_hyst_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)148 trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
149 		      const char *buf, size_t count)
150 {
151 	struct thermal_trip *trip = thermal_trip_of_attr(attr, hyst);
152 	struct thermal_zone_device *tz = to_thermal_zone(dev);
153 	int hyst;
154 
155 	if (kstrtoint(buf, 10, &hyst) || hyst < 0)
156 		return -EINVAL;
157 
158 	guard(thermal_zone)(tz);
159 
160 	if (hyst == trip->hysteresis)
161 		return count;
162 
163 	/*
164 	 * Allow the hysteresis to be updated when the temperature is invalid
165 	 * to allow user space to avoid having to adjust hysteresis after a
166 	 * valid temperature has been set, but in that case just change the
167 	 * value and do nothing else.
168 	 */
169 	if (trip->temperature == THERMAL_TEMP_INVALID) {
170 		WRITE_ONCE(trip->hysteresis, hyst);
171 		return count;
172 	}
173 
174 	if (trip->temperature - hyst <= THERMAL_TEMP_INVALID)
175 		return -EINVAL;
176 
177 	thermal_zone_set_trip_hyst(tz, trip, hyst);
178 
179 	__thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED);
180 
181 	return count;
182 }
183 
184 static ssize_t
trip_point_hyst_show(struct device * dev,struct device_attribute * attr,char * buf)185 trip_point_hyst_show(struct device *dev, struct device_attribute *attr,
186 		     char *buf)
187 {
188 	struct thermal_trip *trip = thermal_trip_of_attr(attr, hyst);
189 
190 	return sysfs_emit(buf, "%d\n", READ_ONCE(trip->hysteresis));
191 }
192 
193 static ssize_t
policy_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)194 policy_store(struct device *dev, struct device_attribute *attr,
195 	     const char *buf, size_t count)
196 {
197 	struct thermal_zone_device *tz = to_thermal_zone(dev);
198 	char name[THERMAL_NAME_LENGTH];
199 	int ret;
200 
201 	strscpy(name, buf);
202 
203 	ret = thermal_zone_device_set_policy(tz, name);
204 	if (!ret)
205 		ret = count;
206 
207 	return ret;
208 }
209 
210 static ssize_t
policy_show(struct device * dev,struct device_attribute * devattr,char * buf)211 policy_show(struct device *dev, struct device_attribute *devattr, char *buf)
212 {
213 	struct thermal_zone_device *tz = to_thermal_zone(dev);
214 
215 	return sysfs_emit(buf, "%s\n", tz->governor->name);
216 }
217 
218 static ssize_t
available_policies_show(struct device * dev,struct device_attribute * devattr,char * buf)219 available_policies_show(struct device *dev, struct device_attribute *devattr,
220 			char *buf)
221 {
222 	return thermal_build_list_of_policies(buf);
223 }
224 
225 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
226 static ssize_t
emul_temp_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)227 emul_temp_store(struct device *dev, struct device_attribute *attr,
228 		const char *buf, size_t count)
229 {
230 	struct thermal_zone_device *tz = to_thermal_zone(dev);
231 	int temperature;
232 
233 	if (kstrtoint(buf, 10, &temperature))
234 		return -EINVAL;
235 
236 	guard(thermal_zone)(tz);
237 
238 	if (tz->ops.set_emul_temp) {
239 		int ret;
240 
241 		ret = tz->ops.set_emul_temp(tz, temperature);
242 		if (ret)
243 			return ret;
244 	} else {
245 		tz->emul_temperature = temperature;
246 	}
247 
248 	__thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
249 
250 	return count;
251 }
252 static DEVICE_ATTR_WO(emul_temp);
253 #endif
254 
255 static ssize_t
sustainable_power_show(struct device * dev,struct device_attribute * devattr,char * buf)256 sustainable_power_show(struct device *dev, struct device_attribute *devattr,
257 		       char *buf)
258 {
259 	struct thermal_zone_device *tz = to_thermal_zone(dev);
260 
261 	if (tz->tzp)
262 		return sysfs_emit(buf, "%u\n", tz->tzp->sustainable_power);
263 	else
264 		return -EIO;
265 }
266 
267 static ssize_t
sustainable_power_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)268 sustainable_power_store(struct device *dev, struct device_attribute *devattr,
269 			const char *buf, size_t count)
270 {
271 	struct thermal_zone_device *tz = to_thermal_zone(dev);
272 	u32 sustainable_power;
273 
274 	if (!tz->tzp)
275 		return -EIO;
276 
277 	if (kstrtou32(buf, 10, &sustainable_power))
278 		return -EINVAL;
279 
280 	tz->tzp->sustainable_power = sustainable_power;
281 
282 	return count;
283 }
284 
285 #define create_s32_tzp_attr(name)					\
286 	static ssize_t							\
287 	name##_show(struct device *dev, struct device_attribute *devattr, \
288 		char *buf)						\
289 	{								\
290 	struct thermal_zone_device *tz = to_thermal_zone(dev);		\
291 									\
292 	if (tz->tzp)							\
293 		return sysfs_emit(buf, "%d\n", tz->tzp->name);		\
294 	else								\
295 		return -EIO;						\
296 	}								\
297 									\
298 	static ssize_t							\
299 	name##_store(struct device *dev, struct device_attribute *devattr, \
300 		const char *buf, size_t count)				\
301 	{								\
302 		struct thermal_zone_device *tz = to_thermal_zone(dev);	\
303 		s32 value;						\
304 									\
305 		if (!tz->tzp)						\
306 			return -EIO;					\
307 									\
308 		if (kstrtos32(buf, 10, &value))				\
309 			return -EINVAL;					\
310 									\
311 		tz->tzp->name = value;					\
312 									\
313 		return count;						\
314 	}								\
315 	static DEVICE_ATTR_RW(name)
316 
317 create_s32_tzp_attr(k_po);
318 create_s32_tzp_attr(k_pu);
319 create_s32_tzp_attr(k_i);
320 create_s32_tzp_attr(k_d);
321 create_s32_tzp_attr(integral_cutoff);
322 create_s32_tzp_attr(slope);
323 create_s32_tzp_attr(offset);
324 #undef create_s32_tzp_attr
325 
326 /*
327  * These are thermal zone device attributes that will always be present.
328  * All the attributes created for tzp (create_s32_tzp_attr) also are always
329  * present on the sysfs interface.
330  */
331 static DEVICE_ATTR_RO(type);
332 static DEVICE_ATTR_RO(temp);
333 static DEVICE_ATTR_RW(policy);
334 static DEVICE_ATTR_RO(available_policies);
335 static DEVICE_ATTR_RW(sustainable_power);
336 
337 /* These thermal zone device attributes are created based on conditions */
338 static DEVICE_ATTR_RW(mode);
339 
340 /* These attributes are unconditionally added to a thermal zone */
341 static struct attribute *thermal_zone_dev_attrs[] = {
342 	&dev_attr_type.attr,
343 	&dev_attr_temp.attr,
344 #if (IS_ENABLED(CONFIG_THERMAL_EMULATION))
345 	&dev_attr_emul_temp.attr,
346 #endif
347 	&dev_attr_policy.attr,
348 	&dev_attr_available_policies.attr,
349 	&dev_attr_sustainable_power.attr,
350 	&dev_attr_k_po.attr,
351 	&dev_attr_k_pu.attr,
352 	&dev_attr_k_i.attr,
353 	&dev_attr_k_d.attr,
354 	&dev_attr_integral_cutoff.attr,
355 	&dev_attr_slope.attr,
356 	&dev_attr_offset.attr,
357 	NULL,
358 };
359 
360 static const struct attribute_group thermal_zone_attribute_group = {
361 	.attrs = thermal_zone_dev_attrs,
362 };
363 
364 static struct attribute *thermal_zone_mode_attrs[] = {
365 	&dev_attr_mode.attr,
366 	NULL,
367 };
368 
369 static const struct attribute_group thermal_zone_mode_attribute_group = {
370 	.attrs = thermal_zone_mode_attrs,
371 };
372 
373 static const struct attribute_group *thermal_zone_attribute_groups[] = {
374 	&thermal_zone_attribute_group,
375 	&thermal_zone_mode_attribute_group,
376 	/* This is not NULL terminated as we create the group dynamically */
377 };
378 
379 /**
380  * create_trip_attrs() - create attributes for trip points
381  * @tz:		the thermal zone device
382  *
383  * helper function to instantiate sysfs entries for every trip
384  * point and its properties of a struct thermal_zone_device.
385  *
386  * Return: 0 on success, the proper error value otherwise.
387  */
create_trip_attrs(struct thermal_zone_device * tz)388 static int create_trip_attrs(struct thermal_zone_device *tz)
389 {
390 	struct thermal_trip_desc *td;
391 	struct attribute **attrs;
392 	int i;
393 
394 	attrs = kzalloc_objs(*attrs, tz->num_trips * 3 + 1);
395 	if (!attrs)
396 		return -ENOMEM;
397 
398 	i = 0;
399 	for_each_trip_desc(tz, td) {
400 		struct thermal_trip_attrs *trip_attrs = &td->trip_attrs;
401 
402 		/* create trip type attribute */
403 		snprintf(trip_attrs->type.name, THERMAL_NAME_LENGTH,
404 			 "trip_point_%d_type", i);
405 
406 		sysfs_attr_init(&trip_attrs->type.attr.attr);
407 		trip_attrs->type.attr.attr.name = trip_attrs->type.name;
408 		trip_attrs->type.attr.attr.mode = S_IRUGO;
409 		trip_attrs->type.attr.show = trip_point_type_show;
410 		attrs[i] = &trip_attrs->type.attr.attr;
411 
412 		/* create trip temp attribute */
413 		snprintf(trip_attrs->temp.name, THERMAL_NAME_LENGTH,
414 			 "trip_point_%d_temp", i);
415 
416 		sysfs_attr_init(&trip_attrs->temp.attr.attr);
417 		trip_attrs->temp.attr.attr.name = trip_attrs->temp.name;
418 		trip_attrs->temp.attr.attr.mode = S_IRUGO;
419 		trip_attrs->temp.attr.show = trip_point_temp_show;
420 		if (td->trip.flags & THERMAL_TRIP_FLAG_RW_TEMP) {
421 			trip_attrs->temp.attr.attr.mode |= S_IWUSR;
422 			trip_attrs->temp.attr.store = trip_point_temp_store;
423 		}
424 		attrs[i + tz->num_trips] = &trip_attrs->temp.attr.attr;
425 
426 		snprintf(trip_attrs->hyst.name, THERMAL_NAME_LENGTH,
427 			 "trip_point_%d_hyst", i);
428 
429 		sysfs_attr_init(&trip_attrs->hyst.attr.attr);
430 		trip_attrs->hyst.attr.attr.name = trip_attrs->hyst.name;
431 		trip_attrs->hyst.attr.attr.mode = S_IRUGO;
432 		trip_attrs->hyst.attr.show = trip_point_hyst_show;
433 		if (td->trip.flags & THERMAL_TRIP_FLAG_RW_HYST) {
434 			trip_attrs->hyst.attr.attr.mode |= S_IWUSR;
435 			trip_attrs->hyst.attr.store = trip_point_hyst_store;
436 		}
437 		attrs[i + 2 * tz->num_trips] = &trip_attrs->hyst.attr.attr;
438 		i++;
439 	}
440 	attrs[tz->num_trips * 3] = NULL;
441 
442 	tz->trips_attribute_group.attrs = attrs;
443 
444 	return 0;
445 }
446 
447 /**
448  * destroy_trip_attrs() - destroy attributes for trip points
449  * @tz:		the thermal zone device
450  *
451  * helper function to free resources allocated by create_trip_attrs()
452  */
destroy_trip_attrs(struct thermal_zone_device * tz)453 static void destroy_trip_attrs(struct thermal_zone_device *tz)
454 {
455 	if (tz)
456 		kfree(tz->trips_attribute_group.attrs);
457 }
458 
thermal_zone_create_device_groups(struct thermal_zone_device * tz)459 int thermal_zone_create_device_groups(struct thermal_zone_device *tz)
460 {
461 	const struct attribute_group **groups;
462 	int i, size, result;
463 
464 	/* we need one extra for trips and the NULL to terminate the array */
465 	size = ARRAY_SIZE(thermal_zone_attribute_groups) + 2;
466 	/* This also takes care of API requirement to be NULL terminated */
467 	groups = kzalloc_objs(*groups, size);
468 	if (!groups)
469 		return -ENOMEM;
470 
471 	for (i = 0; i < size - 2; i++)
472 		groups[i] = thermal_zone_attribute_groups[i];
473 
474 	if (tz->num_trips) {
475 		result = create_trip_attrs(tz);
476 		if (result) {
477 			kfree(groups);
478 
479 			return result;
480 		}
481 
482 		groups[size - 2] = &tz->trips_attribute_group;
483 	}
484 
485 	tz->device.groups = groups;
486 
487 	return 0;
488 }
489 
thermal_zone_destroy_device_groups(struct thermal_zone_device * tz)490 void thermal_zone_destroy_device_groups(struct thermal_zone_device *tz)
491 {
492 	if (!tz)
493 		return;
494 
495 	if (tz->num_trips)
496 		destroy_trip_attrs(tz);
497 
498 	kfree(tz->device.groups);
499 }
500 
501 /* sys I/F for cooling device */
502 static ssize_t
cdev_type_show(struct device * dev,struct device_attribute * attr,char * buf)503 cdev_type_show(struct device *dev, struct device_attribute *attr, char *buf)
504 {
505 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
506 
507 	return sysfs_emit(buf, "%s\n", cdev->type);
508 }
509 
max_state_show(struct device * dev,struct device_attribute * attr,char * buf)510 static ssize_t max_state_show(struct device *dev, struct device_attribute *attr,
511 			      char *buf)
512 {
513 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
514 
515 	return sysfs_emit(buf, "%ld\n", cdev->max_state);
516 }
517 
cur_state_show(struct device * dev,struct device_attribute * attr,char * buf)518 static ssize_t cur_state_show(struct device *dev, struct device_attribute *attr,
519 			      char *buf)
520 {
521 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
522 	unsigned long state;
523 	int ret;
524 
525 	ret = cdev->ops->get_cur_state(cdev, &state);
526 	if (ret)
527 		return ret;
528 	return sysfs_emit(buf, "%ld\n", state);
529 }
530 
531 static ssize_t
cur_state_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)532 cur_state_store(struct device *dev, struct device_attribute *attr,
533 		const char *buf, size_t count)
534 {
535 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
536 	unsigned long state;
537 	int result;
538 
539 	if (sscanf(buf, "%ld\n", &state) != 1)
540 		return -EINVAL;
541 
542 	if ((long)state < 0)
543 		return -EINVAL;
544 
545 	/* Requested state should be less than max_state + 1 */
546 	if (state > cdev->max_state)
547 		return -EINVAL;
548 
549 	guard(cooling_dev)(cdev);
550 
551 	result = cdev->ops->set_cur_state(cdev, state);
552 	if (result)
553 		return result;
554 
555 	thermal_cooling_device_stats_update(cdev, state);
556 
557 	return count;
558 }
559 
560 static struct device_attribute
561 dev_attr_cdev_type = __ATTR(type, 0444, cdev_type_show, NULL);
562 static DEVICE_ATTR_RO(max_state);
563 static DEVICE_ATTR_RW(cur_state);
564 
565 static struct attribute *cooling_device_attrs[] = {
566 	&dev_attr_cdev_type.attr,
567 	&dev_attr_max_state.attr,
568 	&dev_attr_cur_state.attr,
569 	NULL,
570 };
571 
572 static const struct attribute_group cooling_device_attr_group = {
573 	.attrs = cooling_device_attrs,
574 };
575 
576 static const struct attribute_group *cooling_device_attr_groups[] = {
577 	&cooling_device_attr_group,
578 	NULL, /* Space allocated for cooling_device_stats_attr_group */
579 	NULL,
580 };
581 
582 #ifdef CONFIG_THERMAL_STATISTICS
583 struct cooling_dev_stats {
584 	spinlock_t lock;
585 	unsigned int total_trans;
586 	unsigned long state;
587 	ktime_t last_time;
588 	ktime_t *time_in_state;
589 	unsigned int *trans_table;
590 };
591 
update_time_in_state(struct cooling_dev_stats * stats)592 static void update_time_in_state(struct cooling_dev_stats *stats)
593 {
594 	ktime_t now = ktime_get(), delta;
595 
596 	delta = ktime_sub(now, stats->last_time);
597 	stats->time_in_state[stats->state] =
598 		ktime_add(stats->time_in_state[stats->state], delta);
599 	stats->last_time = now;
600 }
601 
thermal_cooling_device_stats_update(struct thermal_cooling_device * cdev,unsigned long new_state)602 void thermal_cooling_device_stats_update(struct thermal_cooling_device *cdev,
603 					 unsigned long new_state)
604 {
605 	struct cooling_dev_stats *stats = cdev->stats;
606 
607 	lockdep_assert_held(&cdev->lock);
608 
609 	if (!stats)
610 		return;
611 
612 	spin_lock(&stats->lock);
613 
614 	if (stats->state == new_state)
615 		goto unlock;
616 
617 	update_time_in_state(stats);
618 	stats->trans_table[stats->state * (cdev->max_state + 1) + new_state]++;
619 	stats->state = new_state;
620 	stats->total_trans++;
621 
622 unlock:
623 	spin_unlock(&stats->lock);
624 }
625 
total_trans_show(struct device * dev,struct device_attribute * attr,char * buf)626 static ssize_t total_trans_show(struct device *dev,
627 				struct device_attribute *attr, char *buf)
628 {
629 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
630 	struct cooling_dev_stats *stats;
631 	int ret;
632 
633 	guard(cooling_dev)(cdev);
634 
635 	stats = cdev->stats;
636 	if (!stats)
637 		return 0;
638 
639 	spin_lock(&stats->lock);
640 	ret = sysfs_emit(buf, "%u\n", stats->total_trans);
641 	spin_unlock(&stats->lock);
642 
643 	return ret;
644 }
645 
646 static ssize_t
time_in_state_ms_show(struct device * dev,struct device_attribute * attr,char * buf)647 time_in_state_ms_show(struct device *dev, struct device_attribute *attr,
648 		      char *buf)
649 {
650 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
651 	struct cooling_dev_stats *stats;
652 	ssize_t len = 0;
653 	int i;
654 
655 	guard(cooling_dev)(cdev);
656 
657 	stats = cdev->stats;
658 	if (!stats)
659 		return 0;
660 
661 	spin_lock(&stats->lock);
662 
663 	update_time_in_state(stats);
664 
665 	for (i = 0; i <= cdev->max_state; i++) {
666 		len += sysfs_emit_at(buf, len, "state%u\t%llu\n", i,
667 				     ktime_to_ms(stats->time_in_state[i]));
668 	}
669 	spin_unlock(&stats->lock);
670 
671 	return len;
672 }
673 
674 static ssize_t
reset_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)675 reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
676 	    size_t count)
677 {
678 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
679 	struct cooling_dev_stats *stats;
680 	int i, states;
681 
682 	guard(cooling_dev)(cdev);
683 
684 	stats = cdev->stats;
685 	if (!stats)
686 		return count;
687 
688 	states = cdev->max_state + 1;
689 
690 	spin_lock(&stats->lock);
691 
692 	stats->total_trans = 0;
693 	stats->last_time = ktime_get();
694 	memset(stats->trans_table, 0,
695 	       states * states * sizeof(*stats->trans_table));
696 
697 	for (i = 0; i < states; i++)
698 		stats->time_in_state[i] = ktime_set(0, 0);
699 
700 	spin_unlock(&stats->lock);
701 
702 	return count;
703 }
704 
trans_table_show(struct device * dev,struct device_attribute * attr,char * buf)705 static ssize_t trans_table_show(struct device *dev,
706 				struct device_attribute *attr, char *buf)
707 {
708 	struct thermal_cooling_device *cdev = to_cooling_device(dev);
709 	struct cooling_dev_stats *stats;
710 	ssize_t len = 0;
711 	int i, j;
712 
713 	guard(cooling_dev)(cdev);
714 
715 	stats = cdev->stats;
716 	if (!stats)
717 		return -ENODATA;
718 
719 	len += snprintf(buf + len, PAGE_SIZE - len, " From  :    To\n");
720 	len += snprintf(buf + len, PAGE_SIZE - len, "       : ");
721 	for (i = 0; i <= cdev->max_state; i++) {
722 		if (len >= PAGE_SIZE)
723 			break;
724 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u  ", i);
725 	}
726 	if (len >= PAGE_SIZE)
727 		return PAGE_SIZE;
728 
729 	len += snprintf(buf + len, PAGE_SIZE - len, "\n");
730 
731 	for (i = 0; i <= cdev->max_state; i++) {
732 		if (len >= PAGE_SIZE)
733 			break;
734 
735 		len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
736 
737 		for (j = 0; j <= cdev->max_state; j++) {
738 			if (len >= PAGE_SIZE)
739 				break;
740 			len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
741 				stats->trans_table[i * (cdev->max_state + 1) + j]);
742 		}
743 		if (len >= PAGE_SIZE)
744 			break;
745 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
746 	}
747 
748 	if (len >= PAGE_SIZE) {
749 		pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
750 		len = -EFBIG;
751 	}
752 
753 	return len;
754 }
755 
756 static DEVICE_ATTR_RO(total_trans);
757 static DEVICE_ATTR_RO(time_in_state_ms);
758 static DEVICE_ATTR_WO(reset);
759 static DEVICE_ATTR_RO(trans_table);
760 
761 static struct attribute *cooling_device_stats_attrs[] = {
762 	&dev_attr_total_trans.attr,
763 	&dev_attr_time_in_state_ms.attr,
764 	&dev_attr_reset.attr,
765 	&dev_attr_trans_table.attr,
766 	NULL
767 };
768 
769 static const struct attribute_group cooling_device_stats_attr_group = {
770 	.attrs = cooling_device_stats_attrs,
771 	.name = "stats"
772 };
773 
cooling_device_stats_setup(struct thermal_cooling_device * cdev)774 static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
775 {
776 	const struct attribute_group *stats_attr_group = NULL;
777 	struct cooling_dev_stats *stats;
778 	/* Total number of states is highest state + 1 */
779 	unsigned long states = cdev->max_state + 1;
780 	int var;
781 
782 	var = sizeof(*stats);
783 	var += sizeof(*stats->time_in_state) * states;
784 	var += sizeof(*stats->trans_table) * states * states;
785 
786 	stats = kzalloc(var, GFP_KERNEL);
787 	if (!stats)
788 		goto out;
789 
790 	stats->time_in_state = (ktime_t *)(stats + 1);
791 	stats->trans_table = (unsigned int *)(stats->time_in_state + states);
792 	cdev->stats = stats;
793 	stats->last_time = ktime_get();
794 
795 	spin_lock_init(&stats->lock);
796 
797 	stats_attr_group = &cooling_device_stats_attr_group;
798 
799 out:
800 	/* Fill the empty slot left in cooling_device_attr_groups */
801 	var = ARRAY_SIZE(cooling_device_attr_groups) - 2;
802 	cooling_device_attr_groups[var] = stats_attr_group;
803 }
804 
cooling_device_stats_destroy(struct thermal_cooling_device * cdev)805 static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
806 {
807 	kfree(cdev->stats);
808 	cdev->stats = NULL;
809 }
810 
811 #else
812 
813 static inline void
cooling_device_stats_setup(struct thermal_cooling_device * cdev)814 cooling_device_stats_setup(struct thermal_cooling_device *cdev) {}
815 static inline void
cooling_device_stats_destroy(struct thermal_cooling_device * cdev)816 cooling_device_stats_destroy(struct thermal_cooling_device *cdev) {}
817 
818 #endif /* CONFIG_THERMAL_STATISTICS */
819 
thermal_cooling_device_setup_sysfs(struct thermal_cooling_device * cdev)820 void thermal_cooling_device_setup_sysfs(struct thermal_cooling_device *cdev)
821 {
822 	cooling_device_stats_setup(cdev);
823 	cdev->device.groups = cooling_device_attr_groups;
824 }
825 
thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device * cdev)826 void thermal_cooling_device_destroy_sysfs(struct thermal_cooling_device *cdev)
827 {
828 	cooling_device_stats_destroy(cdev);
829 }
830 
thermal_cooling_device_stats_reinit(struct thermal_cooling_device * cdev)831 void thermal_cooling_device_stats_reinit(struct thermal_cooling_device *cdev)
832 {
833 	lockdep_assert_held(&cdev->lock);
834 
835 	cooling_device_stats_destroy(cdev);
836 	cooling_device_stats_setup(cdev);
837 }
838 
839 /* these helper will be used only at the time of bindig */
840 ssize_t
trip_point_show(struct device * dev,struct device_attribute * attr,char * buf)841 trip_point_show(struct device *dev, struct device_attribute *attr, char *buf)
842 {
843 	struct thermal_zone_device *tz = to_thermal_zone(dev);
844 	struct thermal_instance *instance;
845 
846 	instance = container_of(attr, struct thermal_instance, attr);
847 
848 	return sysfs_emit(buf, "%d\n", thermal_zone_trip_id(tz, instance->trip));
849 }
850 
851 ssize_t
weight_show(struct device * dev,struct device_attribute * attr,char * buf)852 weight_show(struct device *dev, struct device_attribute *attr, char *buf)
853 {
854 	struct thermal_instance *instance;
855 
856 	instance = container_of(attr, struct thermal_instance, weight_attr);
857 
858 	return sysfs_emit(buf, "%d\n", instance->weight);
859 }
860 
weight_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)861 ssize_t weight_store(struct device *dev, struct device_attribute *attr,
862 		     const char *buf, size_t count)
863 {
864 	struct thermal_zone_device *tz = to_thermal_zone(dev);
865 	struct thermal_instance *instance;
866 	int ret, weight;
867 
868 	ret = kstrtoint(buf, 0, &weight);
869 	if (ret)
870 		return ret;
871 
872 	instance = container_of(attr, struct thermal_instance, weight_attr);
873 
874 	/* Don't race with governors using the 'weight' value */
875 	guard(thermal_zone)(tz);
876 
877 	instance->weight = weight;
878 
879 	thermal_governor_update_tz(tz, THERMAL_INSTANCE_WEIGHT_CHANGED);
880 
881 	return count;
882 }
883