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>
15 * control - Report/change current runtime PM setting of the device
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:
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;
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
30 * wakeup - Report/change current wakeup option for device
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:
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.
40 * (For example, unconfigured USB devices can't issue wakeups.)
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
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.
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.
62 * async - Report/change current async suspend setting for the device
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.
69 * All devices have one of the following two values for power/async:
71 * + "enabled\n" to permit the asynchronous suspend/resume of the device;
72 * + "disabled\n" to forbid it;
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.
80 * autosuspend_delay_ms - Report/change a device's autosuspend_delay value
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
89 * NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
90 * value are used only if the driver calls pm_runtime_use_autosuspend().
92 * wakeup_count - Report the number of wakeup events related to the device
95 const char power_group_name[] = "power";
96 EXPORT_SYMBOL_GPL(power_group_name);
98 static const char ctrl_auto[] = "auto";
99 static const char ctrl_on[] = "on";
101 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
104 return sysfs_emit(buf, "%s\n",
105 dev->power.runtime_auto ? ctrl_auto : ctrl_on);
108 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
109 const char * buf, size_t n)
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);
122 static DEVICE_ATTR_RW(control);
124 static ssize_t runtime_active_time_show(struct device *dev,
125 struct device_attribute *attr,
128 u64 tmp = pm_runtime_active_time(dev);
130 do_div(tmp, NSEC_PER_MSEC);
132 return sysfs_emit(buf, "%llu\n", tmp);
135 static DEVICE_ATTR_RO(runtime_active_time);
137 static ssize_t runtime_suspended_time_show(struct device *dev,
138 struct device_attribute *attr,
141 u64 tmp = pm_runtime_suspended_time(dev);
143 do_div(tmp, NSEC_PER_MSEC);
145 return sysfs_emit(buf, "%llu\n", tmp);
148 static DEVICE_ATTR_RO(runtime_suspended_time);
150 static ssize_t runtime_status_show(struct device *dev,
151 struct device_attribute *attr, char *buf)
155 if (dev->power.runtime_error) {
157 } else if (dev->power.disable_depth) {
158 output = "unsupported";
160 switch (dev->power.runtime_status) {
162 output = "suspended";
165 output = "suspending";
177 return sysfs_emit(buf, "%s\n", output);
180 static DEVICE_ATTR_RO(runtime_status);
182 static ssize_t autosuspend_delay_ms_show(struct device *dev,
183 struct device_attribute *attr,
186 if (!dev->power.use_autosuspend)
189 return sysfs_emit(buf, "%d\n", dev->power.autosuspend_delay);
192 static ssize_t autosuspend_delay_ms_store(struct device *dev,
193 struct device_attribute *attr, const char *buf, size_t n)
197 if (!dev->power.use_autosuspend)
200 if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
204 pm_runtime_set_autosuspend_delay(dev, delay);
209 static DEVICE_ATTR_RW(autosuspend_delay_ms);
211 static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
212 struct device_attribute *attr,
215 s32 value = dev_pm_qos_requested_resume_latency(dev);
218 return sysfs_emit(buf, "n/a\n");
219 if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
222 return sysfs_emit(buf, "%d\n", value);
225 static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
226 struct device_attribute *attr,
227 const char *buf, size_t n)
232 if (!kstrtos32(buf, 0, &value)) {
234 * Prevent users from writing negative or "no constraint" values
237 if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
241 value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
242 } else if (sysfs_streq(buf, "n/a")) {
248 ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
250 return ret < 0 ? ret : n;
253 static DEVICE_ATTR_RW(pm_qos_resume_latency_us);
255 static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
256 struct device_attribute *attr,
259 s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
262 return sysfs_emit(buf, "%s\n", "auto");
263 if (value == PM_QOS_LATENCY_ANY)
264 return sysfs_emit(buf, "%s\n", "any");
266 return sysfs_emit(buf, "%d\n", value);
269 static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
270 struct device_attribute *attr,
271 const char *buf, size_t n)
276 if (kstrtos32(buf, 0, &value) == 0) {
277 /* Users can't write negative values directly */
281 if (sysfs_streq(buf, "auto"))
282 value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
283 else if (sysfs_streq(buf, "any"))
284 value = PM_QOS_LATENCY_ANY;
288 ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
289 return ret < 0 ? ret : n;
292 static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us);
294 static ssize_t pm_qos_no_power_off_show(struct device *dev,
295 struct device_attribute *attr,
298 return sysfs_emit(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
299 & PM_QOS_FLAG_NO_POWER_OFF));
302 static ssize_t pm_qos_no_power_off_store(struct device *dev,
303 struct device_attribute *attr,
304 const char *buf, size_t n)
308 if (kstrtoint(buf, 0, &ret))
311 if (ret != 0 && ret != 1)
314 ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
315 return ret < 0 ? ret : n;
318 static DEVICE_ATTR_RW(pm_qos_no_power_off);
320 #ifdef CONFIG_PM_SLEEP
321 static const char _enabled[] = "enabled";
322 static const char _disabled[] = "disabled";
324 static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
327 return sysfs_emit(buf, "%s\n", device_can_wakeup(dev)
328 ? (device_may_wakeup(dev) ? _enabled : _disabled)
332 static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
333 const char *buf, size_t n)
335 if (!device_can_wakeup(dev))
338 if (sysfs_streq(buf, _enabled))
339 device_set_wakeup_enable(dev, 1);
340 else if (sysfs_streq(buf, _disabled))
341 device_set_wakeup_enable(dev, 0);
347 static DEVICE_ATTR_RW(wakeup);
349 static ssize_t wakeup_count_show(struct device *dev,
350 struct device_attribute *attr, char *buf)
353 bool enabled = false;
355 spin_lock_irq(&dev->power.lock);
356 if (dev->power.wakeup) {
357 count = dev->power.wakeup->wakeup_count;
360 spin_unlock_irq(&dev->power.lock);
363 return sysfs_emit(buf, "\n");
364 return sysfs_emit(buf, "%lu\n", count);
367 static DEVICE_ATTR_RO(wakeup_count);
369 static ssize_t wakeup_active_count_show(struct device *dev,
370 struct device_attribute *attr,
374 bool enabled = false;
376 spin_lock_irq(&dev->power.lock);
377 if (dev->power.wakeup) {
378 count = dev->power.wakeup->active_count;
381 spin_unlock_irq(&dev->power.lock);
384 return sysfs_emit(buf, "\n");
385 return sysfs_emit(buf, "%lu\n", count);
388 static DEVICE_ATTR_RO(wakeup_active_count);
390 static ssize_t wakeup_abort_count_show(struct device *dev,
391 struct device_attribute *attr,
395 bool enabled = false;
397 spin_lock_irq(&dev->power.lock);
398 if (dev->power.wakeup) {
399 count = dev->power.wakeup->wakeup_count;
402 spin_unlock_irq(&dev->power.lock);
405 return sysfs_emit(buf, "\n");
406 return sysfs_emit(buf, "%lu\n", count);
409 static DEVICE_ATTR_RO(wakeup_abort_count);
411 static ssize_t wakeup_expire_count_show(struct device *dev,
412 struct device_attribute *attr,
416 bool enabled = false;
418 spin_lock_irq(&dev->power.lock);
419 if (dev->power.wakeup) {
420 count = dev->power.wakeup->expire_count;
423 spin_unlock_irq(&dev->power.lock);
426 return sysfs_emit(buf, "\n");
427 return sysfs_emit(buf, "%lu\n", count);
430 static DEVICE_ATTR_RO(wakeup_expire_count);
432 static ssize_t wakeup_active_show(struct device *dev,
433 struct device_attribute *attr, char *buf)
436 bool enabled = false;
438 spin_lock_irq(&dev->power.lock);
439 if (dev->power.wakeup) {
440 active = dev->power.wakeup->active;
443 spin_unlock_irq(&dev->power.lock);
446 return sysfs_emit(buf, "\n");
447 return sysfs_emit(buf, "%u\n", active);
450 static DEVICE_ATTR_RO(wakeup_active);
452 static ssize_t wakeup_total_time_ms_show(struct device *dev,
453 struct device_attribute *attr,
457 bool enabled = false;
459 spin_lock_irq(&dev->power.lock);
460 if (dev->power.wakeup) {
461 msec = ktime_to_ms(dev->power.wakeup->total_time);
464 spin_unlock_irq(&dev->power.lock);
467 return sysfs_emit(buf, "\n");
468 return sysfs_emit(buf, "%lld\n", msec);
471 static DEVICE_ATTR_RO(wakeup_total_time_ms);
473 static ssize_t wakeup_max_time_ms_show(struct device *dev,
474 struct device_attribute *attr, char *buf)
477 bool enabled = false;
479 spin_lock_irq(&dev->power.lock);
480 if (dev->power.wakeup) {
481 msec = ktime_to_ms(dev->power.wakeup->max_time);
484 spin_unlock_irq(&dev->power.lock);
487 return sysfs_emit(buf, "\n");
488 return sysfs_emit(buf, "%lld\n", msec);
491 static DEVICE_ATTR_RO(wakeup_max_time_ms);
493 static ssize_t wakeup_last_time_ms_show(struct device *dev,
494 struct device_attribute *attr,
498 bool enabled = false;
500 spin_lock_irq(&dev->power.lock);
501 if (dev->power.wakeup) {
502 msec = ktime_to_ms(dev->power.wakeup->last_time);
505 spin_unlock_irq(&dev->power.lock);
508 return sysfs_emit(buf, "\n");
509 return sysfs_emit(buf, "%lld\n", msec);
512 static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
515 if (dev->power.wakeup && dev->power.wakeup->dev)
516 return device_change_owner(dev->power.wakeup->dev, kuid, kgid);
520 static DEVICE_ATTR_RO(wakeup_last_time_ms);
522 #ifdef CONFIG_PM_AUTOSLEEP
523 static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
524 struct device_attribute *attr,
528 bool enabled = false;
530 spin_lock_irq(&dev->power.lock);
531 if (dev->power.wakeup) {
532 msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
535 spin_unlock_irq(&dev->power.lock);
538 return sysfs_emit(buf, "\n");
539 return sysfs_emit(buf, "%lld\n", msec);
542 static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);
543 #endif /* CONFIG_PM_AUTOSLEEP */
544 #else /* CONFIG_PM_SLEEP */
545 static inline int dpm_sysfs_wakeup_change_owner(struct device *dev, kuid_t kuid,
552 #ifdef CONFIG_PM_ADVANCED_DEBUG
553 static ssize_t runtime_usage_show(struct device *dev,
554 struct device_attribute *attr, char *buf)
556 return sysfs_emit(buf, "%d\n", atomic_read(&dev->power.usage_count));
558 static DEVICE_ATTR_RO(runtime_usage);
560 static ssize_t runtime_active_kids_show(struct device *dev,
561 struct device_attribute *attr,
564 return sysfs_emit(buf, "%d\n", dev->power.ignore_children ?
565 0 : atomic_read(&dev->power.child_count));
567 static DEVICE_ATTR_RO(runtime_active_kids);
569 static ssize_t runtime_enabled_show(struct device *dev,
570 struct device_attribute *attr, char *buf)
574 if (dev->power.disable_depth && !dev->power.runtime_auto)
575 output = "disabled & forbidden";
576 else if (dev->power.disable_depth)
578 else if (!dev->power.runtime_auto)
579 output = "forbidden";
583 return sysfs_emit(buf, "%s\n", output);
585 static DEVICE_ATTR_RO(runtime_enabled);
587 #ifdef CONFIG_PM_SLEEP
588 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
591 return sysfs_emit(buf, "%s\n",
592 device_async_suspend_enabled(dev) ?
593 _enabled : _disabled);
596 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
597 const char *buf, size_t n)
599 if (sysfs_streq(buf, _enabled))
600 device_enable_async_suspend(dev);
601 else if (sysfs_streq(buf, _disabled))
602 device_disable_async_suspend(dev);
608 static DEVICE_ATTR_RW(async);
610 #endif /* CONFIG_PM_SLEEP */
611 #endif /* CONFIG_PM_ADVANCED_DEBUG */
613 static struct attribute *power_attrs[] = {
614 #ifdef CONFIG_PM_ADVANCED_DEBUG
615 #ifdef CONFIG_PM_SLEEP
616 &dev_attr_async.attr,
618 &dev_attr_runtime_status.attr,
619 &dev_attr_runtime_usage.attr,
620 &dev_attr_runtime_active_kids.attr,
621 &dev_attr_runtime_enabled.attr,
622 #endif /* CONFIG_PM_ADVANCED_DEBUG */
625 static const struct attribute_group pm_attr_group = {
626 .name = power_group_name,
627 .attrs = power_attrs,
630 static struct attribute *wakeup_attrs[] = {
631 #ifdef CONFIG_PM_SLEEP
632 &dev_attr_wakeup.attr,
633 &dev_attr_wakeup_count.attr,
634 &dev_attr_wakeup_active_count.attr,
635 &dev_attr_wakeup_abort_count.attr,
636 &dev_attr_wakeup_expire_count.attr,
637 &dev_attr_wakeup_active.attr,
638 &dev_attr_wakeup_total_time_ms.attr,
639 &dev_attr_wakeup_max_time_ms.attr,
640 &dev_attr_wakeup_last_time_ms.attr,
641 #ifdef CONFIG_PM_AUTOSLEEP
642 &dev_attr_wakeup_prevent_sleep_time_ms.attr,
647 static const struct attribute_group pm_wakeup_attr_group = {
648 .name = power_group_name,
649 .attrs = wakeup_attrs,
652 static struct attribute *runtime_attrs[] = {
653 #ifndef CONFIG_PM_ADVANCED_DEBUG
654 &dev_attr_runtime_status.attr,
656 &dev_attr_control.attr,
657 &dev_attr_runtime_suspended_time.attr,
658 &dev_attr_runtime_active_time.attr,
659 &dev_attr_autosuspend_delay_ms.attr,
662 static const struct attribute_group pm_runtime_attr_group = {
663 .name = power_group_name,
664 .attrs = runtime_attrs,
667 static struct attribute *pm_qos_resume_latency_attrs[] = {
668 &dev_attr_pm_qos_resume_latency_us.attr,
671 static const struct attribute_group pm_qos_resume_latency_attr_group = {
672 .name = power_group_name,
673 .attrs = pm_qos_resume_latency_attrs,
676 static struct attribute *pm_qos_latency_tolerance_attrs[] = {
677 &dev_attr_pm_qos_latency_tolerance_us.attr,
680 static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
681 .name = power_group_name,
682 .attrs = pm_qos_latency_tolerance_attrs,
685 static struct attribute *pm_qos_flags_attrs[] = {
686 &dev_attr_pm_qos_no_power_off.attr,
689 static const struct attribute_group pm_qos_flags_attr_group = {
690 .name = power_group_name,
691 .attrs = pm_qos_flags_attrs,
694 int dpm_sysfs_add(struct device *dev)
698 /* No need to create PM sysfs if explicitly disabled. */
699 if (device_pm_not_required(dev))
702 rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
706 if (!pm_runtime_has_no_callbacks(dev)) {
707 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
711 if (device_can_wakeup(dev)) {
712 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
716 if (dev->power.set_latency_tolerance) {
717 rc = sysfs_merge_group(&dev->kobj,
718 &pm_qos_latency_tolerance_attr_group);
722 rc = pm_wakeup_source_sysfs_add(dev);
728 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
730 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
732 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
734 sysfs_remove_group(&dev->kobj, &pm_attr_group);
738 int dpm_sysfs_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
742 if (device_pm_not_required(dev))
745 rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
749 if (!pm_runtime_has_no_callbacks(dev)) {
750 rc = sysfs_group_change_owner(
751 &dev->kobj, &pm_runtime_attr_group, kuid, kgid);
756 if (device_can_wakeup(dev)) {
757 rc = sysfs_group_change_owner(&dev->kobj, &pm_wakeup_attr_group,
762 rc = dpm_sysfs_wakeup_change_owner(dev, kuid, kgid);
767 if (dev->power.set_latency_tolerance) {
768 rc = sysfs_group_change_owner(
769 &dev->kobj, &pm_qos_latency_tolerance_attr_group, kuid,
777 int wakeup_sysfs_add(struct device *dev)
779 int ret = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
782 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
787 void wakeup_sysfs_remove(struct device *dev)
789 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
790 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
793 int pm_qos_sysfs_add_resume_latency(struct device *dev)
795 return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
798 void pm_qos_sysfs_remove_resume_latency(struct device *dev)
800 sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
803 int pm_qos_sysfs_add_flags(struct device *dev)
805 return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
808 void pm_qos_sysfs_remove_flags(struct device *dev)
810 sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
813 int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
815 return sysfs_merge_group(&dev->kobj,
816 &pm_qos_latency_tolerance_attr_group);
819 void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
821 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
824 void rpm_sysfs_remove(struct device *dev)
826 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
829 void dpm_sysfs_remove(struct device *dev)
831 if (device_pm_not_required(dev))
833 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
834 dev_pm_qos_constraints_destroy(dev);
835 rpm_sysfs_remove(dev);
836 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
837 sysfs_remove_group(&dev->kobj, &pm_attr_group);