2 * drivers/base/power/sysfs.c - sysfs entries for device PM
5 #include <linux/device.h>
6 #include <linux/string.h>
7 #include <linux/export.h>
8 #include <linux/pm_qos.h>
9 #include <linux/pm_runtime.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 sprintf(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)
114 cp = memchr(buf, '\n', n);
118 if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
119 pm_runtime_allow(dev);
120 else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
121 pm_runtime_forbid(dev);
128 static DEVICE_ATTR(control, 0644, control_show, control_store);
130 static ssize_t rtpm_active_time_show(struct device *dev,
131 struct device_attribute *attr, char *buf)
134 spin_lock_irq(&dev->power.lock);
135 update_pm_runtime_accounting(dev);
136 ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
137 spin_unlock_irq(&dev->power.lock);
141 static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
143 static ssize_t rtpm_suspended_time_show(struct device *dev,
144 struct device_attribute *attr, char *buf)
147 spin_lock_irq(&dev->power.lock);
148 update_pm_runtime_accounting(dev);
149 ret = sprintf(buf, "%i\n",
150 jiffies_to_msecs(dev->power.suspended_jiffies));
151 spin_unlock_irq(&dev->power.lock);
155 static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
157 static ssize_t rtpm_status_show(struct device *dev,
158 struct device_attribute *attr, char *buf)
162 if (dev->power.runtime_error) {
164 } else if (dev->power.disable_depth) {
167 switch (dev->power.runtime_status) {
184 return sprintf(buf, p);
187 static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
189 static ssize_t autosuspend_delay_ms_show(struct device *dev,
190 struct device_attribute *attr, char *buf)
192 if (!dev->power.use_autosuspend)
194 return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
197 static ssize_t autosuspend_delay_ms_store(struct device *dev,
198 struct device_attribute *attr, const char *buf, size_t n)
202 if (!dev->power.use_autosuspend)
205 if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
209 pm_runtime_set_autosuspend_delay(dev, delay);
214 static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
215 autosuspend_delay_ms_store);
217 static ssize_t pm_qos_resume_latency_show(struct device *dev,
218 struct device_attribute *attr,
221 s32 value = dev_pm_qos_requested_resume_latency(dev);
224 return sprintf(buf, "n/a\n");
225 else if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
228 return sprintf(buf, "%d\n", value);
231 static ssize_t pm_qos_resume_latency_store(struct device *dev,
232 struct device_attribute *attr,
233 const char *buf, size_t n)
238 if (!kstrtos32(buf, 0, &value)) {
240 * Prevent users from writing negative or "no constraint" values
243 if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
247 value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
248 } else if (!strcmp(buf, "n/a") || !strcmp(buf, "n/a\n")) {
254 ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
256 return ret < 0 ? ret : n;
259 static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
260 pm_qos_resume_latency_show, pm_qos_resume_latency_store);
262 static ssize_t pm_qos_latency_tolerance_show(struct device *dev,
263 struct device_attribute *attr,
266 s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
269 return sprintf(buf, "auto\n");
270 else if (value == PM_QOS_LATENCY_ANY)
271 return sprintf(buf, "any\n");
273 return sprintf(buf, "%d\n", value);
276 static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
277 struct device_attribute *attr,
278 const char *buf, size_t n)
283 if (kstrtos32(buf, 0, &value) == 0) {
284 /* Users can't write negative values directly */
288 if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n"))
289 value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
290 else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))
291 value = PM_QOS_LATENCY_ANY;
295 ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
296 return ret < 0 ? ret : n;
299 static DEVICE_ATTR(pm_qos_latency_tolerance_us, 0644,
300 pm_qos_latency_tolerance_show, pm_qos_latency_tolerance_store);
302 static ssize_t pm_qos_no_power_off_show(struct device *dev,
303 struct device_attribute *attr,
306 return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
307 & PM_QOS_FLAG_NO_POWER_OFF));
310 static ssize_t pm_qos_no_power_off_store(struct device *dev,
311 struct device_attribute *attr,
312 const char *buf, size_t n)
316 if (kstrtoint(buf, 0, &ret))
319 if (ret != 0 && ret != 1)
322 ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
323 return ret < 0 ? ret : n;
326 static DEVICE_ATTR(pm_qos_no_power_off, 0644,
327 pm_qos_no_power_off_show, pm_qos_no_power_off_store);
329 #ifdef CONFIG_PM_SLEEP
330 static const char _enabled[] = "enabled";
331 static const char _disabled[] = "disabled";
334 wake_show(struct device * dev, struct device_attribute *attr, char * buf)
336 return sprintf(buf, "%s\n", device_can_wakeup(dev)
337 ? (device_may_wakeup(dev) ? _enabled : _disabled)
342 wake_store(struct device * dev, struct device_attribute *attr,
343 const char * buf, size_t n)
348 if (!device_can_wakeup(dev))
351 cp = memchr(buf, '\n', n);
354 if (len == sizeof _enabled - 1
355 && strncmp(buf, _enabled, sizeof _enabled - 1) == 0)
356 device_set_wakeup_enable(dev, 1);
357 else if (len == sizeof _disabled - 1
358 && strncmp(buf, _disabled, sizeof _disabled - 1) == 0)
359 device_set_wakeup_enable(dev, 0);
365 static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
367 static ssize_t wakeup_count_show(struct device *dev,
368 struct device_attribute *attr, char *buf)
370 unsigned long count = 0;
371 bool enabled = false;
373 spin_lock_irq(&dev->power.lock);
374 if (dev->power.wakeup) {
375 count = dev->power.wakeup->event_count;
378 spin_unlock_irq(&dev->power.lock);
379 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
382 static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
384 static ssize_t wakeup_active_count_show(struct device *dev,
385 struct device_attribute *attr, char *buf)
387 unsigned long count = 0;
388 bool enabled = false;
390 spin_lock_irq(&dev->power.lock);
391 if (dev->power.wakeup) {
392 count = dev->power.wakeup->active_count;
395 spin_unlock_irq(&dev->power.lock);
396 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
399 static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
401 static ssize_t wakeup_abort_count_show(struct device *dev,
402 struct device_attribute *attr,
405 unsigned long count = 0;
406 bool enabled = false;
408 spin_lock_irq(&dev->power.lock);
409 if (dev->power.wakeup) {
410 count = dev->power.wakeup->wakeup_count;
413 spin_unlock_irq(&dev->power.lock);
414 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
417 static DEVICE_ATTR(wakeup_abort_count, 0444, wakeup_abort_count_show, NULL);
419 static ssize_t wakeup_expire_count_show(struct device *dev,
420 struct device_attribute *attr,
423 unsigned long count = 0;
424 bool enabled = false;
426 spin_lock_irq(&dev->power.lock);
427 if (dev->power.wakeup) {
428 count = dev->power.wakeup->expire_count;
431 spin_unlock_irq(&dev->power.lock);
432 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
435 static DEVICE_ATTR(wakeup_expire_count, 0444, wakeup_expire_count_show, NULL);
437 static ssize_t wakeup_active_show(struct device *dev,
438 struct device_attribute *attr, char *buf)
440 unsigned int active = 0;
441 bool enabled = false;
443 spin_lock_irq(&dev->power.lock);
444 if (dev->power.wakeup) {
445 active = dev->power.wakeup->active;
448 spin_unlock_irq(&dev->power.lock);
449 return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
452 static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
454 static ssize_t wakeup_total_time_show(struct device *dev,
455 struct device_attribute *attr, char *buf)
458 bool enabled = false;
460 spin_lock_irq(&dev->power.lock);
461 if (dev->power.wakeup) {
462 msec = ktime_to_ms(dev->power.wakeup->total_time);
465 spin_unlock_irq(&dev->power.lock);
466 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
469 static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
471 static ssize_t wakeup_max_time_show(struct device *dev,
472 struct device_attribute *attr, char *buf)
475 bool enabled = false;
477 spin_lock_irq(&dev->power.lock);
478 if (dev->power.wakeup) {
479 msec = ktime_to_ms(dev->power.wakeup->max_time);
482 spin_unlock_irq(&dev->power.lock);
483 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
486 static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
488 static ssize_t wakeup_last_time_show(struct device *dev,
489 struct device_attribute *attr, char *buf)
492 bool enabled = false;
494 spin_lock_irq(&dev->power.lock);
495 if (dev->power.wakeup) {
496 msec = ktime_to_ms(dev->power.wakeup->last_time);
499 spin_unlock_irq(&dev->power.lock);
500 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
503 static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
505 #ifdef CONFIG_PM_AUTOSLEEP
506 static ssize_t wakeup_prevent_sleep_time_show(struct device *dev,
507 struct device_attribute *attr,
511 bool enabled = false;
513 spin_lock_irq(&dev->power.lock);
514 if (dev->power.wakeup) {
515 msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
518 spin_unlock_irq(&dev->power.lock);
519 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
522 static DEVICE_ATTR(wakeup_prevent_sleep_time_ms, 0444,
523 wakeup_prevent_sleep_time_show, NULL);
524 #endif /* CONFIG_PM_AUTOSLEEP */
525 #endif /* CONFIG_PM_SLEEP */
527 #ifdef CONFIG_PM_ADVANCED_DEBUG
528 static ssize_t rtpm_usagecount_show(struct device *dev,
529 struct device_attribute *attr, char *buf)
531 return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
534 static ssize_t rtpm_children_show(struct device *dev,
535 struct device_attribute *attr, char *buf)
537 return sprintf(buf, "%d\n", dev->power.ignore_children ?
538 0 : atomic_read(&dev->power.child_count));
541 static ssize_t rtpm_enabled_show(struct device *dev,
542 struct device_attribute *attr, char *buf)
544 if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
545 return sprintf(buf, "disabled & forbidden\n");
546 else if (dev->power.disable_depth)
547 return sprintf(buf, "disabled\n");
548 else if (dev->power.runtime_auto == false)
549 return sprintf(buf, "forbidden\n");
550 return sprintf(buf, "enabled\n");
553 static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
554 static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
555 static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);
557 #ifdef CONFIG_PM_SLEEP
558 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
561 return sprintf(buf, "%s\n",
562 device_async_suspend_enabled(dev) ?
563 _enabled : _disabled);
566 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
567 const char *buf, size_t n)
572 cp = memchr(buf, '\n', n);
575 if (len == sizeof _enabled - 1 && strncmp(buf, _enabled, len) == 0)
576 device_enable_async_suspend(dev);
577 else if (len == sizeof _disabled - 1 &&
578 strncmp(buf, _disabled, len) == 0)
579 device_disable_async_suspend(dev);
585 static DEVICE_ATTR(async, 0644, async_show, async_store);
587 #endif /* CONFIG_PM_SLEEP */
588 #endif /* CONFIG_PM_ADVANCED_DEBUG */
590 static struct attribute *power_attrs[] = {
591 #ifdef CONFIG_PM_ADVANCED_DEBUG
592 #ifdef CONFIG_PM_SLEEP
593 &dev_attr_async.attr,
595 &dev_attr_runtime_status.attr,
596 &dev_attr_runtime_usage.attr,
597 &dev_attr_runtime_active_kids.attr,
598 &dev_attr_runtime_enabled.attr,
599 #endif /* CONFIG_PM_ADVANCED_DEBUG */
602 static const struct attribute_group pm_attr_group = {
603 .name = power_group_name,
604 .attrs = power_attrs,
607 static struct attribute *wakeup_attrs[] = {
608 #ifdef CONFIG_PM_SLEEP
609 &dev_attr_wakeup.attr,
610 &dev_attr_wakeup_count.attr,
611 &dev_attr_wakeup_active_count.attr,
612 &dev_attr_wakeup_abort_count.attr,
613 &dev_attr_wakeup_expire_count.attr,
614 &dev_attr_wakeup_active.attr,
615 &dev_attr_wakeup_total_time_ms.attr,
616 &dev_attr_wakeup_max_time_ms.attr,
617 &dev_attr_wakeup_last_time_ms.attr,
618 #ifdef CONFIG_PM_AUTOSLEEP
619 &dev_attr_wakeup_prevent_sleep_time_ms.attr,
624 static const struct attribute_group pm_wakeup_attr_group = {
625 .name = power_group_name,
626 .attrs = wakeup_attrs,
629 static struct attribute *runtime_attrs[] = {
630 #ifndef CONFIG_PM_ADVANCED_DEBUG
631 &dev_attr_runtime_status.attr,
633 &dev_attr_control.attr,
634 &dev_attr_runtime_suspended_time.attr,
635 &dev_attr_runtime_active_time.attr,
636 &dev_attr_autosuspend_delay_ms.attr,
639 static const struct attribute_group pm_runtime_attr_group = {
640 .name = power_group_name,
641 .attrs = runtime_attrs,
644 static struct attribute *pm_qos_resume_latency_attrs[] = {
645 &dev_attr_pm_qos_resume_latency_us.attr,
648 static const struct attribute_group pm_qos_resume_latency_attr_group = {
649 .name = power_group_name,
650 .attrs = pm_qos_resume_latency_attrs,
653 static struct attribute *pm_qos_latency_tolerance_attrs[] = {
654 &dev_attr_pm_qos_latency_tolerance_us.attr,
657 static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
658 .name = power_group_name,
659 .attrs = pm_qos_latency_tolerance_attrs,
662 static struct attribute *pm_qos_flags_attrs[] = {
663 &dev_attr_pm_qos_no_power_off.attr,
666 static const struct attribute_group pm_qos_flags_attr_group = {
667 .name = power_group_name,
668 .attrs = pm_qos_flags_attrs,
671 int dpm_sysfs_add(struct device *dev)
675 rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
679 if (pm_runtime_callbacks_present(dev)) {
680 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
684 if (device_can_wakeup(dev)) {
685 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
689 if (dev->power.set_latency_tolerance) {
690 rc = sysfs_merge_group(&dev->kobj,
691 &pm_qos_latency_tolerance_attr_group);
698 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
700 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
702 sysfs_remove_group(&dev->kobj, &pm_attr_group);
706 int wakeup_sysfs_add(struct device *dev)
708 return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
711 void wakeup_sysfs_remove(struct device *dev)
713 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
716 int pm_qos_sysfs_add_resume_latency(struct device *dev)
718 return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
721 void pm_qos_sysfs_remove_resume_latency(struct device *dev)
723 sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
726 int pm_qos_sysfs_add_flags(struct device *dev)
728 return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
731 void pm_qos_sysfs_remove_flags(struct device *dev)
733 sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
736 int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
738 return sysfs_merge_group(&dev->kobj,
739 &pm_qos_latency_tolerance_attr_group);
742 void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
744 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
747 void rpm_sysfs_remove(struct device *dev)
749 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
752 void dpm_sysfs_remove(struct device *dev)
754 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
755 dev_pm_qos_constraints_destroy(dev);
756 rpm_sysfs_remove(dev);
757 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
758 sysfs_remove_group(&dev->kobj, &pm_attr_group);