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)
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, char *buf)
128 spin_lock_irq(&dev->power.lock);
129 update_pm_runtime_accounting(dev);
130 ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
131 spin_unlock_irq(&dev->power.lock);
135 static DEVICE_ATTR_RO(runtime_active_time);
137 static ssize_t runtime_suspended_time_show(struct device *dev,
138 struct device_attribute *attr, char *buf)
141 spin_lock_irq(&dev->power.lock);
142 update_pm_runtime_accounting(dev);
143 ret = sprintf(buf, "%i\n",
144 jiffies_to_msecs(dev->power.suspended_jiffies));
145 spin_unlock_irq(&dev->power.lock);
149 static DEVICE_ATTR_RO(runtime_suspended_time);
151 static ssize_t runtime_status_show(struct device *dev,
152 struct device_attribute *attr, char *buf)
156 if (dev->power.runtime_error) {
158 } else if (dev->power.disable_depth) {
161 switch (dev->power.runtime_status) {
178 return sprintf(buf, p);
181 static DEVICE_ATTR_RO(runtime_status);
183 static ssize_t autosuspend_delay_ms_show(struct device *dev,
184 struct device_attribute *attr, char *buf)
186 if (!dev->power.use_autosuspend)
188 return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
191 static ssize_t autosuspend_delay_ms_store(struct device *dev,
192 struct device_attribute *attr, const char *buf, size_t n)
196 if (!dev->power.use_autosuspend)
199 if (kstrtol(buf, 10, &delay) != 0 || delay != (int) delay)
203 pm_runtime_set_autosuspend_delay(dev, delay);
208 static DEVICE_ATTR_RW(autosuspend_delay_ms);
210 static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
211 struct device_attribute *attr,
214 s32 value = dev_pm_qos_requested_resume_latency(dev);
217 return sprintf(buf, "n/a\n");
218 if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
221 return sprintf(buf, "%d\n", value);
224 static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
225 struct device_attribute *attr,
226 const char *buf, size_t n)
231 if (!kstrtos32(buf, 0, &value)) {
233 * Prevent users from writing negative or "no constraint" values
236 if (value < 0 || value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
240 value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
241 } else if (sysfs_streq(buf, "n/a")) {
247 ret = dev_pm_qos_update_request(dev->power.qos->resume_latency_req,
249 return ret < 0 ? ret : n;
252 static DEVICE_ATTR_RW(pm_qos_resume_latency_us);
254 static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
255 struct device_attribute *attr,
258 s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
261 return sprintf(buf, "auto\n");
262 if (value == PM_QOS_LATENCY_ANY)
263 return sprintf(buf, "any\n");
265 return sprintf(buf, "%d\n", value);
268 static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
269 struct device_attribute *attr,
270 const char *buf, size_t n)
275 if (kstrtos32(buf, 0, &value) == 0) {
276 /* Users can't write negative values directly */
280 if (sysfs_streq(buf, "auto"))
281 value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
282 else if (sysfs_streq(buf, "any"))
283 value = PM_QOS_LATENCY_ANY;
287 ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
288 return ret < 0 ? ret : n;
291 static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us);
293 static ssize_t pm_qos_no_power_off_show(struct device *dev,
294 struct device_attribute *attr,
297 return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
298 & PM_QOS_FLAG_NO_POWER_OFF));
301 static ssize_t pm_qos_no_power_off_store(struct device *dev,
302 struct device_attribute *attr,
303 const char *buf, size_t n)
307 if (kstrtoint(buf, 0, &ret))
310 if (ret != 0 && ret != 1)
313 ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
314 return ret < 0 ? ret : n;
317 static DEVICE_ATTR_RW(pm_qos_no_power_off);
319 #ifdef CONFIG_PM_SLEEP
320 static const char _enabled[] = "enabled";
321 static const char _disabled[] = "disabled";
323 static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
326 return sprintf(buf, "%s\n", device_can_wakeup(dev)
327 ? (device_may_wakeup(dev) ? _enabled : _disabled)
331 static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
332 const char *buf, size_t n)
334 if (!device_can_wakeup(dev))
337 if (sysfs_streq(buf, _enabled))
338 device_set_wakeup_enable(dev, 1);
339 else if (sysfs_streq(buf, _disabled))
340 device_set_wakeup_enable(dev, 0);
346 static DEVICE_ATTR_RW(wakeup);
348 static ssize_t wakeup_count_show(struct device *dev,
349 struct device_attribute *attr, char *buf)
351 unsigned long count = 0;
352 bool enabled = false;
354 spin_lock_irq(&dev->power.lock);
355 if (dev->power.wakeup) {
356 count = dev->power.wakeup->event_count;
359 spin_unlock_irq(&dev->power.lock);
360 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
363 static DEVICE_ATTR_RO(wakeup_count);
365 static ssize_t wakeup_active_count_show(struct device *dev,
366 struct device_attribute *attr,
369 unsigned long count = 0;
370 bool enabled = false;
372 spin_lock_irq(&dev->power.lock);
373 if (dev->power.wakeup) {
374 count = dev->power.wakeup->active_count;
377 spin_unlock_irq(&dev->power.lock);
378 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
381 static DEVICE_ATTR_RO(wakeup_active_count);
383 static ssize_t wakeup_abort_count_show(struct device *dev,
384 struct device_attribute *attr,
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->wakeup_count;
395 spin_unlock_irq(&dev->power.lock);
396 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
399 static DEVICE_ATTR_RO(wakeup_abort_count);
401 static ssize_t wakeup_expire_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->expire_count;
413 spin_unlock_irq(&dev->power.lock);
414 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
417 static DEVICE_ATTR_RO(wakeup_expire_count);
419 static ssize_t wakeup_active_show(struct device *dev,
420 struct device_attribute *attr, char *buf)
422 unsigned int active = 0;
423 bool enabled = false;
425 spin_lock_irq(&dev->power.lock);
426 if (dev->power.wakeup) {
427 active = dev->power.wakeup->active;
430 spin_unlock_irq(&dev->power.lock);
431 return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
434 static DEVICE_ATTR_RO(wakeup_active);
436 static ssize_t wakeup_total_time_ms_show(struct device *dev,
437 struct device_attribute *attr,
441 bool enabled = false;
443 spin_lock_irq(&dev->power.lock);
444 if (dev->power.wakeup) {
445 msec = ktime_to_ms(dev->power.wakeup->total_time);
448 spin_unlock_irq(&dev->power.lock);
449 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
452 static DEVICE_ATTR_RO(wakeup_total_time_ms);
454 static ssize_t wakeup_max_time_ms_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->max_time);
465 spin_unlock_irq(&dev->power.lock);
466 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
469 static DEVICE_ATTR_RO(wakeup_max_time_ms);
471 static ssize_t wakeup_last_time_ms_show(struct device *dev,
472 struct device_attribute *attr,
476 bool enabled = false;
478 spin_lock_irq(&dev->power.lock);
479 if (dev->power.wakeup) {
480 msec = ktime_to_ms(dev->power.wakeup->last_time);
483 spin_unlock_irq(&dev->power.lock);
484 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
487 static DEVICE_ATTR_RO(wakeup_last_time_ms);
489 #ifdef CONFIG_PM_AUTOSLEEP
490 static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
491 struct device_attribute *attr,
495 bool enabled = false;
497 spin_lock_irq(&dev->power.lock);
498 if (dev->power.wakeup) {
499 msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
502 spin_unlock_irq(&dev->power.lock);
503 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
506 static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);
507 #endif /* CONFIG_PM_AUTOSLEEP */
508 #endif /* CONFIG_PM_SLEEP */
510 #ifdef CONFIG_PM_ADVANCED_DEBUG
511 static ssize_t runtime_usage_show(struct device *dev,
512 struct device_attribute *attr, char *buf)
514 return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
516 static DEVICE_ATTR_RO(runtime_usage);
518 static ssize_t runtime_active_kids_show(struct device *dev,
519 struct device_attribute *attr,
522 return sprintf(buf, "%d\n", dev->power.ignore_children ?
523 0 : atomic_read(&dev->power.child_count));
525 static DEVICE_ATTR_RO(runtime_active_kids);
527 static ssize_t runtime_enabled_show(struct device *dev,
528 struct device_attribute *attr, char *buf)
530 if (dev->power.disable_depth && (dev->power.runtime_auto == false))
531 return sprintf(buf, "disabled & forbidden\n");
532 if (dev->power.disable_depth)
533 return sprintf(buf, "disabled\n");
534 if (dev->power.runtime_auto == false)
535 return sprintf(buf, "forbidden\n");
536 return sprintf(buf, "enabled\n");
538 static DEVICE_ATTR_RO(runtime_enabled);
540 #ifdef CONFIG_PM_SLEEP
541 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
544 return sprintf(buf, "%s\n",
545 device_async_suspend_enabled(dev) ?
546 _enabled : _disabled);
549 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
550 const char *buf, size_t n)
552 if (sysfs_streq(buf, _enabled))
553 device_enable_async_suspend(dev);
554 else if (sysfs_streq(buf, _disabled))
555 device_disable_async_suspend(dev);
561 static DEVICE_ATTR_RW(async);
563 #endif /* CONFIG_PM_SLEEP */
564 #endif /* CONFIG_PM_ADVANCED_DEBUG */
566 static struct attribute *power_attrs[] = {
567 #ifdef CONFIG_PM_ADVANCED_DEBUG
568 #ifdef CONFIG_PM_SLEEP
569 &dev_attr_async.attr,
571 &dev_attr_runtime_status.attr,
572 &dev_attr_runtime_usage.attr,
573 &dev_attr_runtime_active_kids.attr,
574 &dev_attr_runtime_enabled.attr,
575 #endif /* CONFIG_PM_ADVANCED_DEBUG */
578 static const struct attribute_group pm_attr_group = {
579 .name = power_group_name,
580 .attrs = power_attrs,
583 static struct attribute *wakeup_attrs[] = {
584 #ifdef CONFIG_PM_SLEEP
585 &dev_attr_wakeup.attr,
586 &dev_attr_wakeup_count.attr,
587 &dev_attr_wakeup_active_count.attr,
588 &dev_attr_wakeup_abort_count.attr,
589 &dev_attr_wakeup_expire_count.attr,
590 &dev_attr_wakeup_active.attr,
591 &dev_attr_wakeup_total_time_ms.attr,
592 &dev_attr_wakeup_max_time_ms.attr,
593 &dev_attr_wakeup_last_time_ms.attr,
594 #ifdef CONFIG_PM_AUTOSLEEP
595 &dev_attr_wakeup_prevent_sleep_time_ms.attr,
600 static const struct attribute_group pm_wakeup_attr_group = {
601 .name = power_group_name,
602 .attrs = wakeup_attrs,
605 static struct attribute *runtime_attrs[] = {
606 #ifndef CONFIG_PM_ADVANCED_DEBUG
607 &dev_attr_runtime_status.attr,
609 &dev_attr_control.attr,
610 &dev_attr_runtime_suspended_time.attr,
611 &dev_attr_runtime_active_time.attr,
612 &dev_attr_autosuspend_delay_ms.attr,
615 static const struct attribute_group pm_runtime_attr_group = {
616 .name = power_group_name,
617 .attrs = runtime_attrs,
620 static struct attribute *pm_qos_resume_latency_attrs[] = {
621 &dev_attr_pm_qos_resume_latency_us.attr,
624 static const struct attribute_group pm_qos_resume_latency_attr_group = {
625 .name = power_group_name,
626 .attrs = pm_qos_resume_latency_attrs,
629 static struct attribute *pm_qos_latency_tolerance_attrs[] = {
630 &dev_attr_pm_qos_latency_tolerance_us.attr,
633 static const struct attribute_group pm_qos_latency_tolerance_attr_group = {
634 .name = power_group_name,
635 .attrs = pm_qos_latency_tolerance_attrs,
638 static struct attribute *pm_qos_flags_attrs[] = {
639 &dev_attr_pm_qos_no_power_off.attr,
642 static const struct attribute_group pm_qos_flags_attr_group = {
643 .name = power_group_name,
644 .attrs = pm_qos_flags_attrs,
647 int dpm_sysfs_add(struct device *dev)
651 rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
655 if (pm_runtime_callbacks_present(dev)) {
656 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
660 if (device_can_wakeup(dev)) {
661 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
665 if (dev->power.set_latency_tolerance) {
666 rc = sysfs_merge_group(&dev->kobj,
667 &pm_qos_latency_tolerance_attr_group);
674 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
676 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
678 sysfs_remove_group(&dev->kobj, &pm_attr_group);
682 int wakeup_sysfs_add(struct device *dev)
684 return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
687 void wakeup_sysfs_remove(struct device *dev)
689 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
692 int pm_qos_sysfs_add_resume_latency(struct device *dev)
694 return sysfs_merge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
697 void pm_qos_sysfs_remove_resume_latency(struct device *dev)
699 sysfs_unmerge_group(&dev->kobj, &pm_qos_resume_latency_attr_group);
702 int pm_qos_sysfs_add_flags(struct device *dev)
704 return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
707 void pm_qos_sysfs_remove_flags(struct device *dev)
709 sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_attr_group);
712 int pm_qos_sysfs_add_latency_tolerance(struct device *dev)
714 return sysfs_merge_group(&dev->kobj,
715 &pm_qos_latency_tolerance_attr_group);
718 void pm_qos_sysfs_remove_latency_tolerance(struct device *dev)
720 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
723 void rpm_sysfs_remove(struct device *dev)
725 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
728 void dpm_sysfs_remove(struct device *dev)
730 sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group);
731 dev_pm_qos_constraints_destroy(dev);
732 rpm_sysfs_remove(dev);
733 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
734 sysfs_remove_group(&dev->kobj, &pm_attr_group);