xref: /linux/drivers/base/power/sysfs.c (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* sysfs entries for device PM */
3 #include <linux/device.h>
4 #include <linux/kobject.h>
5 #include <linux/string.h>
6 #include <linux/export.h>
7 #include <linux/pm_qos.h>
8 #include <linux/pm_runtime.h>
9 #include <linux/pm_wakeup.h>
10 #include <linux/atomic.h>
11 #include <linux/jiffies.h>
12 #include "power.h"
13 
14 /*
15  *	control - Report/change current runtime PM setting of the device
16  *
17  *	Runtime power management of a device can be blocked with the help of
18  *	this attribute.  All devices have one of the following two values for
19  *	the power/control file:
20  *
21  *	 + "auto\n" to allow the device to be power managed at run time;
22  *	 + "on\n" to prevent the device from being power managed at run time;
23  *
24  *	The default for all devices is "auto", which means that devices may be
25  *	subject to automatic power management, depending on their drivers.
26  *	Changing this attribute to "on" prevents the driver from power managing
27  *	the device at run time.  Doing that while the device is suspended causes
28  *	it to be woken up.
29  *
30  *	wakeup - Report/change current wakeup option for device
31  *
32  *	Some devices support "wakeup" events, which are hardware signals
33  *	used to activate devices from suspended or low power states.  Such
34  *	devices have one of three values for the sysfs power/wakeup file:
35  *
36  *	 + "enabled\n" to issue the events;
37  *	 + "disabled\n" not to do so; or
38  *	 + "\n" for temporary or permanent inability to issue wakeup.
39  *
40  *	(For example, unconfigured USB devices can't issue wakeups.)
41  *
42  *	Familiar examples of devices that can issue wakeup events include
43  *	keyboards and mice (both PS2 and USB styles), power buttons, modems,
44  *	"Wake-On-LAN" Ethernet links, GPIO lines, and more.  Some events
45  *	will wake the entire system from a suspend state; others may just
46  *	wake up the device (if the system as a whole is already active).
47  *	Some wakeup events use normal IRQ lines; other use special out
48  *	of band signaling.
49  *
50  *	It is the responsibility of device drivers to enable (or disable)
51  *	wakeup signaling as part of changing device power states, respecting
52  *	the policy choices provided through the driver model.
53  *
54  *	Devices may not be able to generate wakeup events from all power
55  *	states.  Also, the events may be ignored in some configurations;
56  *	for example, they might need help from other devices that aren't
57  *	active, or which may have wakeup disabled.  Some drivers rely on
58  *	wakeup events internally (unless they are disabled), keeping
59  *	their hardware in low power modes whenever they're unused.  This
60  *	saves runtime power, without requiring system-wide sleep states.
61  *
62  *	async - Report/change current async suspend setting for the device
63  *
64  *	Asynchronous suspend and resume of the device during system-wide power
65  *	state transitions can be enabled by writing "enabled" to this file.
66  *	Analogously, if "disabled" is written to this file, the device will be
67  *	suspended and resumed synchronously.
68  *
69  *	All devices have one of the following two values for power/async:
70  *
71  *	 + "enabled\n" to permit the asynchronous suspend/resume of the device;
72  *	 + "disabled\n" to forbid it;
73  *
74  *	NOTE: It generally is unsafe to permit the asynchronous suspend/resume
75  *	of a device unless it is certain that all of the PM dependencies of the
76  *	device are known to the PM core.  However, for some devices this
77  *	attribute is set to "enabled" by bus type code or device drivers and in
78  *	that cases it should be safe to leave the default value.
79  *
80  *	autosuspend_delay_ms - Report/change a device's autosuspend_delay value
81  *
82  *	Some drivers don't want to carry out a runtime suspend as soon as a
83  *	device becomes idle; they want it always to remain idle for some period
84  *	of time before suspending it.  This period is the autosuspend_delay
85  *	value (expressed in milliseconds) and it can be controlled by the user.
86  *	If the value is negative then the device will never be runtime
87  *	suspended.
88  *
89  *	NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
90  *	value are used only if the driver calls pm_runtime_use_autosuspend().
91  *
92  *	wakeup_count - Report the number of wakeup events related to the device
93  */
94 
95 const char power_group_name[] = "power";
96 EXPORT_SYMBOL_GPL(power_group_name);
97 
98 static const char ctrl_auto[] = "auto";
99 static const char ctrl_on[] = "on";
100 
101 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
102 			    char *buf)
103 {
104 	return sprintf(buf, "%s\n",
105 				dev->power.runtime_auto ? ctrl_auto : ctrl_on);
106 }
107 
108 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
109 			     const char * buf, size_t n)
110 {
111 	device_lock(dev);
112 	if (sysfs_streq(buf, ctrl_auto))
113 		pm_runtime_allow(dev);
114 	else if (sysfs_streq(buf, ctrl_on))
115 		pm_runtime_forbid(dev);
116 	else
117 		n = -EINVAL;
118 	device_unlock(dev);
119 	return n;
120 }
121 
122 static DEVICE_ATTR_RW(control);
123 
124 static ssize_t runtime_active_time_show(struct device *dev,
125 				struct device_attribute *attr, char *buf)
126 {
127 	int ret;
128 	u64 tmp = pm_runtime_active_time(dev);
129 	do_div(tmp, NSEC_PER_MSEC);
130 	ret = sprintf(buf, "%llu\n", tmp);
131 	return ret;
132 }
133 
134 static DEVICE_ATTR_RO(runtime_active_time);
135 
136 static ssize_t runtime_suspended_time_show(struct device *dev,
137 				struct device_attribute *attr, char *buf)
138 {
139 	int ret;
140 	u64 tmp = pm_runtime_suspended_time(dev);
141 	do_div(tmp, NSEC_PER_MSEC);
142 	ret = sprintf(buf, "%llu\n", tmp);
143 	return ret;
144 }
145 
146 static DEVICE_ATTR_RO(runtime_suspended_time);
147 
148 static ssize_t runtime_status_show(struct device *dev,
149 				struct device_attribute *attr, char *buf)
150 {
151 	const char *p;
152 
153 	if (dev->power.runtime_error) {
154 		p = "error\n";
155 	} else if (dev->power.disable_depth) {
156 		p = "unsupported\n";
157 	} else {
158 		switch (dev->power.runtime_status) {
159 		case RPM_SUSPENDED:
160 			p = "suspended\n";
161 			break;
162 		case RPM_SUSPENDING:
163 			p = "suspending\n";
164 			break;
165 		case RPM_RESUMING:
166 			p = "resuming\n";
167 			break;
168 		case RPM_ACTIVE:
169 			p = "active\n";
170 			break;
171 		default:
172 			return -EIO;
173 		}
174 	}
175 	return sprintf(buf, p);
176 }
177 
178 static DEVICE_ATTR_RO(runtime_status);
179 
180 static ssize_t autosuspend_delay_ms_show(struct device *dev,
181 		struct device_attribute *attr, char *buf)
182 {
183 	if (!dev->power.use_autosuspend)
184 		return -EIO;
185 	return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
186 }
187 
188 static ssize_t autosuspend_delay_ms_store(struct device *dev,
189 		struct device_attribute *attr, const char *buf, size_t n)
190 {
191 	long delay;
192 
193 	if (!dev->power.use_autosuspend)
194 		return -EIO;
195 
196 	if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
197 		return -EINVAL;
198 
199 	device_lock(dev);
200 	pm_runtime_set_autosuspend_delay(dev, delay);
201 	device_unlock(dev);
202 	return n;
203 }
204 
205 static DEVICE_ATTR_RW(autosuspend_delay_ms);
206 
207 static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
208 					     struct device_attribute *attr,
209 					     char *buf)
210 {
211 	s32 value = dev_pm_qos_requested_resume_latency(dev);
212 
213 	if (value == 0)
214 		return sprintf(buf, "n/a\n");
215 	if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
216 		value = 0;
217 
218 	return sprintf(buf, "%d\n", value);
219 }
220 
221 static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
222 					      struct device_attribute *attr,
223 					      const char *buf, size_t n)
224 {
225 	s32 value;
226 	int ret;
227 
228 	if (!kstrtos32(buf, 0, &value)) {
229 		/*
230 		 * Prevent users from writing negative or "no constraint" values
231 		 * directly.
232 		 */
233 		if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
234 			return -EINVAL;
235 
236 		if (value == 0)
237 			value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
238 	} else if (sysfs_streq(buf, "n/a")) {
239 		value = 0;
240 	} else {
241 		return -EINVAL;
242 	}
243 
244 	ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
245 					value);
246 	return ret < 0 ? ret : n;
247 }
248 
249 static DEVICE_ATTR_RW(pm_qos_resume_latency_us);
250 
251 static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
252 						struct device_attribute *attr,
253 						char *buf)
254 {
255 	s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
256 
257 	if (value < 0)
258 		return sprintf(buf, "auto\n");
259 	if (value == PM_QOS_LATENCY_ANY)
260 		return sprintf(buf, "any\n");
261 
262 	return sprintf(buf, "%d\n", value);
263 }
264 
265 static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
266 						 struct device_attribute *attr,
267 						 const char *buf, size_t n)
268 {
269 	s32 value;
270 	int ret;
271 
272 	if (kstrtos32(buf, 0, &value) == 0) {
273 		/* Users can't write negative values directly */
274 		if (value < 0)
275 			return -EINVAL;
276 	} else {
277 		if (sysfs_streq(buf, "auto"))
278 			value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
279 		else if (sysfs_streq(buf, "any"))
280 			value = PM_QOS_LATENCY_ANY;
281 		else
282 			return -EINVAL;
283 	}
284 	ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
285 	return ret < 0 ? ret : n;
286 }
287 
288 static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us);
289 
290 static ssize_t pm_qos_no_power_off_show(struct device *dev,
291 					struct device_attribute *attr,
292 					char *buf)
293 {
294 	return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
295 					& PM_QOS_FLAG_NO_POWER_OFF));
296 }
297 
298 static ssize_t pm_qos_no_power_off_store(struct device *dev,
299 					 struct device_attribute *attr,
300 					 const char *buf, size_t n)
301 {
302 	int ret;
303 
304 	if (kstrtoint(buf, 0, &ret))
305 		return -EINVAL;
306 
307 	if (ret != 0 && ret != 1)
308 		return -EINVAL;
309 
310 	ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
311 	return ret < 0 ? ret : n;
312 }
313 
314 static DEVICE_ATTR_RW(pm_qos_no_power_off);
315 
316 #ifdef CONFIG_PM_SLEEP
317 static const char _enabled[] = "enabled";
318 static const char _disabled[] = "disabled";
319 
320 static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
321 			   char *buf)
322 {
323 	return sprintf(buf, "%s\n", device_can_wakeup(dev)
324 		? (device_may_wakeup(dev) ? _enabled : _disabled)
325 		: "");
326 }
327 
328 static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
329 			    const char *buf, size_t n)
330 {
331 	if (!device_can_wakeup(dev))
332 		return -EINVAL;
333 
334 	if (sysfs_streq(buf, _enabled))
335 		device_set_wakeup_enable(dev, 1);
336 	else if (sysfs_streq(buf, _disabled))
337 		device_set_wakeup_enable(dev, 0);
338 	else
339 		return -EINVAL;
340 	return n;
341 }
342 
343 static DEVICE_ATTR_RW(wakeup);
344 
345 static ssize_t wakeup_count_show(struct device *dev,
346 				 struct device_attribute *attr, char *buf)
347 {
348 	unsigned long count = 0;
349 	bool enabled = false;
350 
351 	spin_lock_irq(&dev->power.lock);
352 	if (dev->power.wakeup) {
353 		count = dev->power.wakeup->wakeup_count;
354 		enabled = true;
355 	}
356 	spin_unlock_irq(&dev->power.lock);
357 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
358 }
359 
360 static DEVICE_ATTR_RO(wakeup_count);
361 
362 static ssize_t wakeup_active_count_show(struct device *dev,
363 					struct device_attribute *attr,
364 					char *buf)
365 {
366 	unsigned long count = 0;
367 	bool enabled = false;
368 
369 	spin_lock_irq(&dev->power.lock);
370 	if (dev->power.wakeup) {
371 		count = dev->power.wakeup->active_count;
372 		enabled = true;
373 	}
374 	spin_unlock_irq(&dev->power.lock);
375 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
376 }
377 
378 static DEVICE_ATTR_RO(wakeup_active_count);
379 
380 static ssize_t wakeup_abort_count_show(struct device *dev,
381 				       struct device_attribute *attr,
382 				       char *buf)
383 {
384 	unsigned long count = 0;
385 	bool enabled = false;
386 
387 	spin_lock_irq(&dev->power.lock);
388 	if (dev->power.wakeup) {
389 		count = dev->power.wakeup->wakeup_count;
390 		enabled = true;
391 	}
392 	spin_unlock_irq(&dev->power.lock);
393 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
394 }
395 
396 static DEVICE_ATTR_RO(wakeup_abort_count);
397 
398 static ssize_t wakeup_expire_count_show(struct device *dev,
399 					struct device_attribute *attr,
400 					char *buf)
401 {
402 	unsigned long count = 0;
403 	bool enabled = false;
404 
405 	spin_lock_irq(&dev->power.lock);
406 	if (dev->power.wakeup) {
407 		count = dev->power.wakeup->expire_count;
408 		enabled = true;
409 	}
410 	spin_unlock_irq(&dev->power.lock);
411 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
412 }
413 
414 static DEVICE_ATTR_RO(wakeup_expire_count);
415 
416 static ssize_t wakeup_active_show(struct device *dev,
417 				  struct device_attribute *attr, char *buf)
418 {
419 	unsigned int active = 0;
420 	bool enabled = false;
421 
422 	spin_lock_irq(&dev->power.lock);
423 	if (dev->power.wakeup) {
424 		active = dev->power.wakeup->active;
425 		enabled = true;
426 	}
427 	spin_unlock_irq(&dev->power.lock);
428 	return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
429 }
430 
431 static DEVICE_ATTR_RO(wakeup_active);
432 
433 static ssize_t wakeup_total_time_ms_show(struct device *dev,
434 					 struct device_attribute *attr,
435 					 char *buf)
436 {
437 	s64 msec = 0;
438 	bool enabled = false;
439 
440 	spin_lock_irq(&dev->power.lock);
441 	if (dev->power.wakeup) {
442 		msec = ktime_to_ms(dev->power.wakeup->total_time);
443 		enabled = true;
444 	}
445 	spin_unlock_irq(&dev->power.lock);
446 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
447 }
448 
449 static DEVICE_ATTR_RO(wakeup_total_time_ms);
450 
451 static ssize_t wakeup_max_time_ms_show(struct device *dev,
452 				       struct device_attribute *attr, char *buf)
453 {
454 	s64 msec = 0;
455 	bool enabled = false;
456 
457 	spin_lock_irq(&dev->power.lock);
458 	if (dev->power.wakeup) {
459 		msec = ktime_to_ms(dev->power.wakeup->max_time);
460 		enabled = true;
461 	}
462 	spin_unlock_irq(&dev->power.lock);
463 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
464 }
465 
466 static DEVICE_ATTR_RO(wakeup_max_time_ms);
467 
468 static ssize_t wakeup_last_time_ms_show(struct device *dev,
469 					struct device_attribute *attr,
470 					char *buf)
471 {
472 	s64 msec = 0;
473 	bool enabled = false;
474 
475 	spin_lock_irq(&dev->power.lock);
476 	if (dev->power.wakeup) {
477 		msec = ktime_to_ms(dev->power.wakeup->last_time);
478 		enabled = true;
479 	}
480 	spin_unlock_irq(&dev->power.lock);
481 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
482 }
483 
484 static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
485 						kgid_t kgid)
486 {
487 	if (dev->power.wakeup && dev->power.wakeup->dev)
488 		return device_change_owner(dev->power.wakeup->dev, kuid, kgid);
489 	return 0;
490 }
491 
492 static DEVICE_ATTR_RO(wakeup_last_time_ms);
493 
494 #ifdef CONFIG_PM_AUTOSLEEP
495 static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
496 						 struct device_attribute *attr,
497 						 char *buf)
498 {
499 	s64 msec = 0;
500 	bool enabled = false;
501 
502 	spin_lock_irq(&dev->power.lock);
503 	if (dev->power.wakeup) {
504 		msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
505 		enabled = true;
506 	}
507 	spin_unlock_irq(&dev->power.lock);
508 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
509 }
510 
511 static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);
512 #endif /* CONFIG_PM_AUTOSLEEP */
513 #else /* CONFIG_PM_SLEEP */
514 static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
515 						kgid_t kgid)
516 {
517 	return 0;
518 }
519 #endif
520 
521 #ifdef CONFIG_PM_ADVANCED_DEBUG
522 static ssize_t runtime_usage_show(struct device *dev,
523 				  struct device_attribute *attr, char *buf)
524 {
525 	return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
526 }
527 static DEVICE_ATTR_RO(runtime_usage);
528 
529 static ssize_t runtime_active_kids_show(struct device *dev,
530 					struct device_attribute *attr,
531 					char *buf)
532 {
533 	return sprintf(buf, "%d\n", dev->power.ignore_children ?
534 		0 : atomic_read(&dev->power.child_count));
535 }
536 static DEVICE_ATTR_RO(runtime_active_kids);
537 
538 static ssize_t runtime_enabled_show(struct device *dev,
539 				    struct device_attribute *attr, char *buf)
540 {
541 	if (dev->power.disable_depth && (dev->power.runtime_auto == false))
542 		return sprintf(buf, "disabled & forbidden\n");
543 	if (dev->power.disable_depth)
544 		return sprintf(buf, "disabled\n");
545 	if (dev->power.runtime_auto == false)
546 		return sprintf(buf, "forbidden\n");
547 	return sprintf(buf, "enabled\n");
548 }
549 static DEVICE_ATTR_RO(runtime_enabled);
550 
551 #ifdef CONFIG_PM_SLEEP
552 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
553 			  char *buf)
554 {
555 	return sprintf(buf, "%s\n",
556 			device_async_suspend_enabled(dev) ?
557 				_enabled : _disabled);
558 }
559 
560 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
561 			   const char *buf, size_t n)
562 {
563 	if (sysfs_streq(buf, _enabled))
564 		device_enable_async_suspend(dev);
565 	else if (sysfs_streq(buf, _disabled))
566 		device_disable_async_suspend(dev);
567 	else
568 		return -EINVAL;
569 	return n;
570 }
571 
572 static DEVICE_ATTR_RW(async);
573 
574 #endif /* CONFIG_PM_SLEEP */
575 #endif /* CONFIG_PM_ADVANCED_DEBUG */
576 
577 static struct attribute *power_attrs[] = {
578 #ifdef CONFIG_PM_ADVANCED_DEBUG
579 #ifdef CONFIG_PM_SLEEP
580 	&dev_attr_async.attr,
581 #endif
582 	&dev_attr_runtime_status.attr,
583 	&dev_attr_runtime_usage.attr,
584 	&dev_attr_runtime_active_kids.attr,
585 	&dev_attr_runtime_enabled.attr,
586 #endif /* CONFIG_PM_ADVANCED_DEBUG */
587 	NULL,
588 };
589 static const struct attribute_group pm_attr_group = {
590 	.name	= power_group_name,
591 	.attrs	= power_attrs,
592 };
593 
594 static struct attribute *wakeup_attrs[] = {
595 #ifdef CONFIG_PM_SLEEP
596 	&dev_attr_wakeup.attr,
597 	&dev_attr_wakeup_count.attr,
598 	&dev_attr_wakeup_active_count.attr,
599 	&dev_attr_wakeup_abort_count.attr,
600 	&dev_attr_wakeup_expire_count.attr,
601 	&dev_attr_wakeup_active.attr,
602 	&dev_attr_wakeup_total_time_ms.attr,
603 	&dev_attr_wakeup_max_time_ms.attr,
604 	&dev_attr_wakeup_last_time_ms.attr,
605 #ifdef CONFIG_PM_AUTOSLEEP
606 	&dev_attr_wakeup_prevent_sleep_time_ms.attr,
607 #endif
608 #endif
609 	NULL,
610 };
611 static const struct attribute_group pm_wakeup_attr_group = {
612 	.name	= power_group_name,
613 	.attrs	= wakeup_attrs,
614 };
615 
616 static struct attribute *runtime_attrs[] = {
617 #ifndef CONFIG_PM_ADVANCED_DEBUG
618 	&dev_attr_runtime_status.attr,
619 #endif
620 	&dev_attr_control.attr,
621 	&dev_attr_runtime_suspended_time.attr,
622 	&dev_attr_runtime_active_time.attr,
623 	&dev_attr_autosuspend_delay_ms.attr,
624 	NULL,
625 };
626 static const struct attribute_group pm_runtime_attr_group = {
627 	.name	= power_group_name,
628 	.attrs	= runtime_attrs,
629 };
630 
631 static struct attribute *pm_qos_resume_latency_attrs[] = {
632 	&dev_attr_pm_qos_resume_latency_us.attr,
633 	NULL,
634 };
635 static const struct attribute_group pm_qos_resume_latency_attr_group = {
636 	.name	= power_group_name,
637 	.attrs	= pm_qos_resume_latency_attrs,
638 };
639 
640 static struct attribute *pm_qos_latency_tolerance_attrs[] = {
641 	&dev_attr_pm_qos_latency_tolerance_us.attr,
642 	NULL,
643 };
644 static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
645 	.name	= power_group_name,
646 	.attrs	= pm_qos_latency_tolerance_attrs,
647 };
648 
649 static struct attribute *pm_qos_flags_attrs[] = {
650 	&dev_attr_pm_qos_no_power_off.attr,
651 	NULL,
652 };
653 static const struct attribute_group pm_qos_flags_attr_group = {
654 	.name	= power_group_name,
655 	.attrs	= pm_qos_flags_attrs,
656 };
657 
658 int dpm_sysfs_add(struct device *dev)
659 {
660 	int rc;
661 
662 	/* No need to create PM sysfs if explicitly disabled. */
663 	if (device_pm_not_required(dev))
664 		return 0;
665 
666 	rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
667 	if (rc)
668 		return rc;
669 
670 	if (!pm_runtime_has_no_callbacks(dev)) {
671 		rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
672 		if (rc)
673 			goto err_out;
674 	}
675 	if (device_can_wakeup(dev)) {
676 		rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
677 		if (rc)
678 			goto err_runtime;
679 	}
680 	if (dev->power.set_latency_tolerance) {
681 		rc = sysfs_merge_group(&dev->kobj,
682 				       &pm_qos_latency_tolerance_attr_group);
683 		if (rc)
684 			goto err_wakeup;
685 	}
686 	rc = pm_wakeup_source_sysfs_add(dev);
687 	if (rc)
688 		goto err_latency;
689 	return 0;
690 
691  err_latency:
692 	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
693  err_wakeup:
694 	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
695  err_runtime:
696 	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
697  err_out:
698 	sysfs_remove_group(&dev->kobj, &pm_attr_group);
699 	return rc;
700 }
701 
702 int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
703 {
704 	int rc;
705 
706 	if (device_pm_not_required(dev))
707 		return 0;
708 
709 	rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
710 	if (rc)
711 		return rc;
712 
713 	if (!pm_runtime_has_no_callbacks(dev)) {
714 		rc = sysfs_group_change_owner(
715 			&dev->kobj, &pm_runtime_attr_group, kuid, kgid);
716 		if (rc)
717 			return rc;
718 	}
719 
720 	if (device_can_wakeup(dev)) {
721 		rc = sysfs_group_change_owner(&dev->kobj, &pm_wakeup_attr_group,
722 					      kuid, kgid);
723 		if (rc)
724 			return rc;
725 
726 		rc = dpm_sysfs_wakeup_change_owner(dev, kuid, kgid);
727 		if (rc)
728 			return rc;
729 	}
730 
731 	if (dev->power.set_latency_tolerance) {
732 		rc = sysfs_group_change_owner(
733 			&dev->kobj, &pm_qos_latency_tolerance_attr_group, kuid,
734 			kgid);
735 		if (rc)
736 			return rc;
737 	}
738 	return 0;
739 }
740 
741 int wakeup_sysfs_add(struct device *dev)
742 {
743 	int ret = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
744 
745 	if (!ret)
746 		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
747 
748 	return ret;
749 }
750 
751 void wakeup_sysfs_remove(struct device *dev)
752 {
753 	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
754 	kobject_uevent(&dev->kobj, KOBJ_CHANGE);
755 }
756 
757 int pm_qos_sysfs_add_resume_latency(struct device *dev)
758 {
759 	return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
760 }
761 
762 void pm_qos_sysfs_remove_resume_latency(struct device *dev)
763 {
764 	sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
765 }
766 
767 int pm_qos_sysfs_add_flags(struct device *dev)
768 {
769 	return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
770 }
771 
772 void pm_qos_sysfs_remove_flags(struct device *dev)
773 {
774 	sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
775 }
776 
777 int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
778 {
779 	return sysfs_merge_group(&dev->kobj,
780 				 &pm_qos_latency_tolerance_attr_group);
781 }
782 
783 void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
784 {
785 	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
786 }
787 
788 void rpm_sysfs_remove(struct device *dev)
789 {
790 	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
791 }
792 
793 void dpm_sysfs_remove(struct device *dev)
794 {
795 	if (device_pm_not_required(dev))
796 		return;
797 	sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
798 	dev_pm_qos_constraints_destroy(dev);
799 	rpm_sysfs_remove(dev);
800 	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
801 	sysfs_remove_group(&dev->kobj, &pm_attr_group);
802 }
803