1 // SPDX-License-Identifier: GPL-2.0
2 /* sysfs entries for device PM */
3 #include <linux/device.h>
4 #include <linux/string.h>
5 #include <linux/export.h>
6 #include <linux/pm_qos.h>
7 #include <linux/pm_runtime.h>
8 #include <linux/pm_wakeup.h>
9 #include <linux/atomic.h>
10 #include <linux/jiffies.h>
14 * control - Report/change current runtime PM setting of the device
16 * Runtime power management of a device can be blocked with the help of
17 * this attribute. All devices have one of the following two values for
18 * the power/control file:
20 * + "auto\n" to allow the device to be power managed at run time;
21 * + "on\n" to prevent the device from being power managed at run time;
23 * The default for all devices is "auto", which means that devices may be
24 * subject to automatic power management, depending on their drivers.
25 * Changing this attribute to "on" prevents the driver from power managing
26 * the device at run time. Doing that while the device is suspended causes
29 * wakeup - Report/change current wakeup option for device
31 * Some devices support "wakeup" events, which are hardware signals
32 * used to activate devices from suspended or low power states. Such
33 * devices have one of three values for the sysfs power/wakeup file:
35 * + "enabled\n" to issue the events;
36 * + "disabled\n" not to do so; or
37 * + "\n" for temporary or permanent inability to issue wakeup.
39 * (For example, unconfigured USB devices can't issue wakeups.)
41 * Familiar examples of devices that can issue wakeup events include
42 * keyboards and mice (both PS2 and USB styles), power buttons, modems,
43 * "Wake-On-LAN" Ethernet links, GPIO lines, and more. Some events
44 * will wake the entire system from a suspend state; others may just
45 * wake up the device (if the system as a whole is already active).
46 * Some wakeup events use normal IRQ lines; other use special out
49 * It is the responsibility of device drivers to enable (or disable)
50 * wakeup signaling as part of changing device power states, respecting
51 * the policy choices provided through the driver model.
53 * Devices may not be able to generate wakeup events from all power
54 * states. Also, the events may be ignored in some configurations;
55 * for example, they might need help from other devices that aren't
56 * active, or which may have wakeup disabled. Some drivers rely on
57 * wakeup events internally (unless they are disabled), keeping
58 * their hardware in low power modes whenever they're unused. This
59 * saves runtime power, without requiring system-wide sleep states.
61 * async - Report/change current async suspend setting for the device
63 * Asynchronous suspend and resume of the device during system-wide power
64 * state transitions can be enabled by writing "enabled" to this file.
65 * Analogously, if "disabled" is written to this file, the device will be
66 * suspended and resumed synchronously.
68 * All devices have one of the following two values for power/async:
70 * + "enabled\n" to permit the asynchronous suspend/resume of the device;
71 * + "disabled\n" to forbid it;
73 * NOTE: It generally is unsafe to permit the asynchronous suspend/resume
74 * of a device unless it is certain that all of the PM dependencies of the
75 * device are known to the PM core. However, for some devices this
76 * attribute is set to "enabled" by bus type code or device drivers and in
77 * that cases it should be safe to leave the default value.
79 * autosuspend_delay_ms - Report/change a device's autosuspend_delay value
81 * Some drivers don't want to carry out a runtime suspend as soon as a
82 * device becomes idle; they want it always to remain idle for some period
83 * of time before suspending it. This period is the autosuspend_delay
84 * value (expressed in milliseconds) and it can be controlled by the user.
85 * If the value is negative then the device will never be runtime
88 * NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
89 * value are used only if the driver calls pm_runtime_use_autosuspend().
91 * wakeup_count - Report the number of wakeup events related to the device
94 const char power_group_name[] = "power";
95 EXPORT_SYMBOL_GPL(power_group_name);
97 static const char ctrl_auto[] = "auto";
98 static const char ctrl_on[] = "on";
100 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
103 return sprintf(buf, "%s\n",
104 dev->power.runtime_auto ? ctrl_auto : ctrl_on);
107 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
108 const char * buf, size_t n)
111 if (sysfs_streq(buf, ctrl_auto))
112 pm_runtime_allow(dev);
113 else if (sysfs_streq(buf, ctrl_on))
114 pm_runtime_forbid(dev);
121 static DEVICE_ATTR_RW(control);
123 static ssize_t runtime_active_time_show(struct device *dev,
124 struct device_attribute *attr, char *buf)
127 u64 tmp = pm_runtime_active_time(dev);
128 do_div(tmp, NSEC_PER_MSEC);
129 ret = sprintf(buf, "%llu\n", tmp);
133 static DEVICE_ATTR_RO(runtime_active_time);
135 static ssize_t runtime_suspended_time_show(struct device *dev,
136 struct device_attribute *attr, char *buf)
139 u64 tmp = pm_runtime_suspended_time(dev);
140 do_div(tmp, NSEC_PER_MSEC);
141 ret = sprintf(buf, "%llu\n", tmp);
145 static DEVICE_ATTR_RO(runtime_suspended_time);
147 static ssize_t runtime_status_show(struct device *dev,
148 struct device_attribute *attr, char *buf)
152 if (dev->power.runtime_error) {
154 } else if (dev->power.disable_depth) {
157 switch (dev->power.runtime_status) {
174 return sprintf(buf, p);
177 static DEVICE_ATTR_RO(runtime_status);
179 static ssize_t autosuspend_delay_ms_show(struct device *dev,
180 struct device_attribute *attr, char *buf)
182 if (!dev->power.use_autosuspend)
184 return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
187 static ssize_t autosuspend_delay_ms_store(struct device *dev,
188 struct device_attribute *attr, const char *buf, size_t n)
192 if (!dev->power.use_autosuspend)
195 if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
199 pm_runtime_set_autosuspend_delay(dev, delay);
204 static DEVICE_ATTR_RW(autosuspend_delay_ms);
206 static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
207 struct device_attribute *attr,
210 s32 value = dev_pm_qos_requested_resume_latency(dev);
213 return sprintf(buf, "n/a\n");
214 if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
217 return sprintf(buf, "%d\n", value);
220 static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
221 struct device_attribute *attr,
222 const char *buf, size_t n)
227 if (!kstrtos32(buf, 0, &value)) {
229 * Prevent users from writing negative or "no constraint" values
232 if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
236 value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
237 } else if (sysfs_streq(buf, "n/a")) {
243 ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
245 return ret < 0 ? ret : n;
248 static DEVICE_ATTR_RW(pm_qos_resume_latency_us);
250 static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
251 struct device_attribute *attr,
254 s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
257 return sprintf(buf, "auto\n");
258 if (value == PM_QOS_LATENCY_ANY)
259 return sprintf(buf, "any\n");
261 return sprintf(buf, "%d\n", value);
264 static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
265 struct device_attribute *attr,
266 const char *buf, size_t n)
271 if (kstrtos32(buf, 0, &value) == 0) {
272 /* Users can't write negative values directly */
276 if (sysfs_streq(buf, "auto"))
277 value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
278 else if (sysfs_streq(buf, "any"))
279 value = PM_QOS_LATENCY_ANY;
283 ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
284 return ret < 0 ? ret : n;
287 static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us);
289 static ssize_t pm_qos_no_power_off_show(struct device *dev,
290 struct device_attribute *attr,
293 return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
294 & PM_QOS_FLAG_NO_POWER_OFF));
297 static ssize_t pm_qos_no_power_off_store(struct device *dev,
298 struct device_attribute *attr,
299 const char *buf, size_t n)
303 if (kstrtoint(buf, 0, &ret))
306 if (ret != 0 && ret != 1)
309 ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
310 return ret < 0 ? ret : n;
313 static DEVICE_ATTR_RW(pm_qos_no_power_off);
315 #ifdef CONFIG_PM_SLEEP
316 static const char _enabled[] = "enabled";
317 static const char _disabled[] = "disabled";
319 static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
322 return sprintf(buf, "%s\n", device_can_wakeup(dev)
323 ? (device_may_wakeup(dev) ? _enabled : _disabled)
327 static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
328 const char *buf, size_t n)
330 if (!device_can_wakeup(dev))
333 if (sysfs_streq(buf, _enabled))
334 device_set_wakeup_enable(dev, 1);
335 else if (sysfs_streq(buf, _disabled))
336 device_set_wakeup_enable(dev, 0);
342 static DEVICE_ATTR_RW(wakeup);
344 static ssize_t wakeup_count_show(struct device *dev,
345 struct device_attribute *attr, char *buf)
347 unsigned long count = 0;
348 bool enabled = false;
350 spin_lock_irq(&dev->power.lock);
351 if (dev->power.wakeup) {
352 count = dev->power.wakeup->wakeup_count;
355 spin_unlock_irq(&dev->power.lock);
356 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
359 static DEVICE_ATTR_RO(wakeup_count);
361 static ssize_t wakeup_active_count_show(struct device *dev,
362 struct device_attribute *attr,
365 unsigned long count = 0;
366 bool enabled = false;
368 spin_lock_irq(&dev->power.lock);
369 if (dev->power.wakeup) {
370 count = dev->power.wakeup->active_count;
373 spin_unlock_irq(&dev->power.lock);
374 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
377 static DEVICE_ATTR_RO(wakeup_active_count);
379 static ssize_t wakeup_abort_count_show(struct device *dev,
380 struct device_attribute *attr,
383 unsigned long count = 0;
384 bool enabled = false;
386 spin_lock_irq(&dev->power.lock);
387 if (dev->power.wakeup) {
388 count = dev->power.wakeup->wakeup_count;
391 spin_unlock_irq(&dev->power.lock);
392 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
395 static DEVICE_ATTR_RO(wakeup_abort_count);
397 static ssize_t wakeup_expire_count_show(struct device *dev,
398 struct device_attribute *attr,
401 unsigned long count = 0;
402 bool enabled = false;
404 spin_lock_irq(&dev->power.lock);
405 if (dev->power.wakeup) {
406 count = dev->power.wakeup->expire_count;
409 spin_unlock_irq(&dev->power.lock);
410 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
413 static DEVICE_ATTR_RO(wakeup_expire_count);
415 static ssize_t wakeup_active_show(struct device *dev,
416 struct device_attribute *attr, char *buf)
418 unsigned int active = 0;
419 bool enabled = false;
421 spin_lock_irq(&dev->power.lock);
422 if (dev->power.wakeup) {
423 active = dev->power.wakeup->active;
426 spin_unlock_irq(&dev->power.lock);
427 return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
430 static DEVICE_ATTR_RO(wakeup_active);
432 static ssize_t wakeup_total_time_ms_show(struct device *dev,
433 struct device_attribute *attr,
437 bool enabled = false;
439 spin_lock_irq(&dev->power.lock);
440 if (dev->power.wakeup) {
441 msec = ktime_to_ms(dev->power.wakeup->total_time);
444 spin_unlock_irq(&dev->power.lock);
445 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
448 static DEVICE_ATTR_RO(wakeup_total_time_ms);
450 static ssize_t wakeup_max_time_ms_show(struct device *dev,
451 struct device_attribute *attr, char *buf)
454 bool enabled = false;
456 spin_lock_irq(&dev->power.lock);
457 if (dev->power.wakeup) {
458 msec = ktime_to_ms(dev->power.wakeup->max_time);
461 spin_unlock_irq(&dev->power.lock);
462 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
465 static DEVICE_ATTR_RO(wakeup_max_time_ms);
467 static ssize_t wakeup_last_time_ms_show(struct device *dev,
468 struct device_attribute *attr,
472 bool enabled = false;
474 spin_lock_irq(&dev->power.lock);
475 if (dev->power.wakeup) {
476 msec = ktime_to_ms(dev->power.wakeup->last_time);
479 spin_unlock_irq(&dev->power.lock);
480 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
483 static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
486 if (dev->power.wakeup && dev->power.wakeup->dev)
487 return device_change_owner(dev->power.wakeup->dev, kuid, kgid);
491 static DEVICE_ATTR_RO(wakeup_last_time_ms);
493 #ifdef CONFIG_PM_AUTOSLEEP
494 static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
495 struct device_attribute *attr,
499 bool enabled = false;
501 spin_lock_irq(&dev->power.lock);
502 if (dev->power.wakeup) {
503 msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
506 spin_unlock_irq(&dev->power.lock);
507 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
510 static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);
511 #endif /* CONFIG_PM_AUTOSLEEP */
512 #else /* CONFIG_PM_SLEEP */
513 static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
520 #ifdef CONFIG_PM_ADVANCED_DEBUG
521 static ssize_t runtime_usage_show(struct device *dev,
522 struct device_attribute *attr, char *buf)
524 return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
526 static DEVICE_ATTR_RO(runtime_usage);
528 static ssize_t runtime_active_kids_show(struct device *dev,
529 struct device_attribute *attr,
532 return sprintf(buf, "%d\n", dev->power.ignore_children ?
533 0 : atomic_read(&dev->power.child_count));
535 static DEVICE_ATTR_RO(runtime_active_kids);
537 static ssize_t runtime_enabled_show(struct device *dev,
538 struct device_attribute *attr, char *buf)
540 if (dev->power.disable_depth && (dev->power.runtime_auto == false))
541 return sprintf(buf, "disabled & forbidden\n");
542 if (dev->power.disable_depth)
543 return sprintf(buf, "disabled\n");
544 if (dev->power.runtime_auto == false)
545 return sprintf(buf, "forbidden\n");
546 return sprintf(buf, "enabled\n");
548 static DEVICE_ATTR_RO(runtime_enabled);
550 #ifdef CONFIG_PM_SLEEP
551 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
554 return sprintf(buf, "%s\n",
555 device_async_suspend_enabled(dev) ?
556 _enabled : _disabled);
559 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
560 const char *buf, size_t n)
562 if (sysfs_streq(buf, _enabled))
563 device_enable_async_suspend(dev);
564 else if (sysfs_streq(buf, _disabled))
565 device_disable_async_suspend(dev);
571 static DEVICE_ATTR_RW(async);
573 #endif /* CONFIG_PM_SLEEP */
574 #endif /* CONFIG_PM_ADVANCED_DEBUG */
576 static struct attribute *power_attrs[] = {
577 #ifdef CONFIG_PM_ADVANCED_DEBUG
578 #ifdef CONFIG_PM_SLEEP
579 &dev_attr_async.attr,
581 &dev_attr_runtime_status.attr,
582 &dev_attr_runtime_usage.attr,
583 &dev_attr_runtime_active_kids.attr,
584 &dev_attr_runtime_enabled.attr,
585 #endif /* CONFIG_PM_ADVANCED_DEBUG */
588 static const struct attribute_group pm_attr_group = {
589 .name = power_group_name,
590 .attrs = power_attrs,
593 static struct attribute *wakeup_attrs[] = {
594 #ifdef CONFIG_PM_SLEEP
595 &dev_attr_wakeup.attr,
596 &dev_attr_wakeup_count.attr,
597 &dev_attr_wakeup_active_count.attr,
598 &dev_attr_wakeup_abort_count.attr,
599 &dev_attr_wakeup_expire_count.attr,
600 &dev_attr_wakeup_active.attr,
601 &dev_attr_wakeup_total_time_ms.attr,
602 &dev_attr_wakeup_max_time_ms.attr,
603 &dev_attr_wakeup_last_time_ms.attr,
604 #ifdef CONFIG_PM_AUTOSLEEP
605 &dev_attr_wakeup_prevent_sleep_time_ms.attr,
610 static const struct attribute_group pm_wakeup_attr_group = {
611 .name = power_group_name,
612 .attrs = wakeup_attrs,
615 static struct attribute *runtime_attrs[] = {
616 #ifndef CONFIG_PM_ADVANCED_DEBUG
617 &dev_attr_runtime_status.attr,
619 &dev_attr_control.attr,
620 &dev_attr_runtime_suspended_time.attr,
621 &dev_attr_runtime_active_time.attr,
622 &dev_attr_autosuspend_delay_ms.attr,
625 static const struct attribute_group pm_runtime_attr_group = {
626 .name = power_group_name,
627 .attrs = runtime_attrs,
630 static struct attribute *pm_qos_resume_latency_attrs[] = {
631 &dev_attr_pm_qos_resume_latency_us.attr,
634 static const struct attribute_group pm_qos_resume_latency_attr_group = {
635 .name = power_group_name,
636 .attrs = pm_qos_resume_latency_attrs,
639 static struct attribute *pm_qos_latency_tolerance_attrs[] = {
640 &dev_attr_pm_qos_latency_tolerance_us.attr,
643 static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
644 .name = power_group_name,
645 .attrs = pm_qos_latency_tolerance_attrs,
648 static struct attribute *pm_qos_flags_attrs[] = {
649 &dev_attr_pm_qos_no_power_off.attr,
652 static const struct attribute_group pm_qos_flags_attr_group = {
653 .name = power_group_name,
654 .attrs = pm_qos_flags_attrs,
657 int dpm_sysfs_add(struct device *dev)
661 /* No need to create PM sysfs if explicitly disabled. */
662 if (device_pm_not_required(dev))
665 rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
669 if (pm_runtime_callbacks_present(dev)) {
670 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
674 if (device_can_wakeup(dev)) {
675 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
679 if (dev->power.set_latency_tolerance) {
680 rc = sysfs_merge_group(&dev->kobj,
681 &pm_qos_latency_tolerance_attr_group);
685 rc = pm_wakeup_source_sysfs_add(dev);
691 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
693 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
695 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
697 sysfs_remove_group(&dev->kobj, &pm_attr_group);
701 int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
705 if (device_pm_not_required(dev))
708 rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
712 if (pm_runtime_callbacks_present(dev)) {
713 rc = sysfs_group_change_owner(
714 &dev->kobj, &pm_runtime_attr_group, kuid, kgid);
719 if (device_can_wakeup(dev)) {
720 rc = sysfs_group_change_owner(&dev->kobj, &pm_wakeup_attr_group,
725 rc = dpm_sysfs_wakeup_change_owner(dev, kuid, kgid);
730 if (dev->power.set_latency_tolerance) {
731 rc = sysfs_group_change_owner(
732 &dev->kobj, &pm_qos_latency_tolerance_attr_group, kuid,
740 int wakeup_sysfs_add(struct device *dev)
742 return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
745 void wakeup_sysfs_remove(struct device *dev)
747 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
750 int pm_qos_sysfs_add_resume_latency(struct device *dev)
752 return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
755 void pm_qos_sysfs_remove_resume_latency(struct device *dev)
757 sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
760 int pm_qos_sysfs_add_flags(struct device *dev)
762 return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
765 void pm_qos_sysfs_remove_flags(struct device *dev)
767 sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
770 int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
772 return sysfs_merge_group(&dev->kobj,
773 &pm_qos_latency_tolerance_attr_group);
776 void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
778 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
781 void rpm_sysfs_remove(struct device *dev)
783 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
786 void dpm_sysfs_remove(struct device *dev)
788 if (device_pm_not_required(dev))
790 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
791 dev_pm_qos_constraints_destroy(dev);
792 rpm_sysfs_remove(dev);
793 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
794 sysfs_remove_group(&dev->kobj, &pm_attr_group);