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 static const char enabled[] = "enabled";
96 static const char disabled[] = "disabled";
98 const char power_group_name[] = "power";
99 EXPORT_SYMBOL_GPL(power_group_name);
101 #ifdef CONFIG_PM_RUNTIME
102 static const char ctrl_auto[] = "auto";
103 static const char ctrl_on[] = "on";
105 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
108 return sprintf(buf, "%s\n",
109 dev->power.runtime_auto ? ctrl_auto : ctrl_on);
112 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
113 const char * buf, size_t n)
118 cp = memchr(buf, '\n', n);
122 if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
123 pm_runtime_allow(dev);
124 else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
125 pm_runtime_forbid(dev);
132 static DEVICE_ATTR(control, 0644, control_show, control_store);
134 static ssize_t rtpm_active_time_show(struct device *dev,
135 struct device_attribute *attr, char *buf)
138 spin_lock_irq(&dev->power.lock);
139 update_pm_runtime_accounting(dev);
140 ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
141 spin_unlock_irq(&dev->power.lock);
145 static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
147 static ssize_t rtpm_suspended_time_show(struct device *dev,
148 struct device_attribute *attr, char *buf)
151 spin_lock_irq(&dev->power.lock);
152 update_pm_runtime_accounting(dev);
153 ret = sprintf(buf, "%i\n",
154 jiffies_to_msecs(dev->power.suspended_jiffies));
155 spin_unlock_irq(&dev->power.lock);
159 static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
161 static ssize_t rtpm_status_show(struct device *dev,
162 struct device_attribute *attr, char *buf)
166 if (dev->power.runtime_error) {
168 } else if (dev->power.disable_depth) {
171 switch (dev->power.runtime_status) {
188 return sprintf(buf, p);
191 static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
193 static ssize_t autosuspend_delay_ms_show(struct device *dev,
194 struct device_attribute *attr, char *buf)
196 if (!dev->power.use_autosuspend)
198 return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
201 static ssize_t autosuspend_delay_ms_store(struct device *dev,
202 struct device_attribute *attr, const char *buf, size_t n)
206 if (!dev->power.use_autosuspend)
209 if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
213 pm_runtime_set_autosuspend_delay(dev, delay);
218 static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
219 autosuspend_delay_ms_store);
221 static ssize_t pm_qos_latency_show(struct device *dev,
222 struct device_attribute *attr, char *buf)
224 return sprintf(buf, "%d\n", dev->power.pq_req->node.prio);
227 static ssize_t pm_qos_latency_store(struct device *dev,
228 struct device_attribute *attr,
229 const char *buf, size_t n)
234 if (kstrtos32(buf, 0, &value))
240 ret = dev_pm_qos_update_request(dev->power.pq_req, value);
241 return ret < 0 ? ret : n;
244 static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
245 pm_qos_latency_show, pm_qos_latency_store);
246 #endif /* CONFIG_PM_RUNTIME */
248 #ifdef CONFIG_PM_SLEEP
250 wake_show(struct device * dev, struct device_attribute *attr, char * buf)
252 return sprintf(buf, "%s\n", device_can_wakeup(dev)
253 ? (device_may_wakeup(dev) ? enabled : disabled)
258 wake_store(struct device * dev, struct device_attribute *attr,
259 const char * buf, size_t n)
264 if (!device_can_wakeup(dev))
267 cp = memchr(buf, '\n', n);
270 if (len == sizeof enabled - 1
271 && strncmp(buf, enabled, sizeof enabled - 1) == 0)
272 device_set_wakeup_enable(dev, 1);
273 else if (len == sizeof disabled - 1
274 && strncmp(buf, disabled, sizeof disabled - 1) == 0)
275 device_set_wakeup_enable(dev, 0);
281 static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
283 static ssize_t wakeup_count_show(struct device *dev,
284 struct device_attribute *attr, char *buf)
286 unsigned long count = 0;
287 bool enabled = false;
289 spin_lock_irq(&dev->power.lock);
290 if (dev->power.wakeup) {
291 count = dev->power.wakeup->event_count;
294 spin_unlock_irq(&dev->power.lock);
295 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
298 static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
300 static ssize_t wakeup_active_count_show(struct device *dev,
301 struct device_attribute *attr, char *buf)
303 unsigned long count = 0;
304 bool enabled = false;
306 spin_lock_irq(&dev->power.lock);
307 if (dev->power.wakeup) {
308 count = dev->power.wakeup->active_count;
311 spin_unlock_irq(&dev->power.lock);
312 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
315 static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
317 static ssize_t wakeup_abort_count_show(struct device *dev,
318 struct device_attribute *attr,
321 unsigned long count = 0;
322 bool enabled = false;
324 spin_lock_irq(&dev->power.lock);
325 if (dev->power.wakeup) {
326 count = dev->power.wakeup->wakeup_count;
329 spin_unlock_irq(&dev->power.lock);
330 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
333 static DEVICE_ATTR(wakeup_abort_count, 0444, wakeup_abort_count_show, NULL);
335 static ssize_t wakeup_expire_count_show(struct device *dev,
336 struct device_attribute *attr,
339 unsigned long count = 0;
340 bool enabled = false;
342 spin_lock_irq(&dev->power.lock);
343 if (dev->power.wakeup) {
344 count = dev->power.wakeup->expire_count;
347 spin_unlock_irq(&dev->power.lock);
348 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
351 static DEVICE_ATTR(wakeup_expire_count, 0444, wakeup_expire_count_show, NULL);
353 static ssize_t wakeup_active_show(struct device *dev,
354 struct device_attribute *attr, char *buf)
356 unsigned int active = 0;
357 bool enabled = false;
359 spin_lock_irq(&dev->power.lock);
360 if (dev->power.wakeup) {
361 active = dev->power.wakeup->active;
364 spin_unlock_irq(&dev->power.lock);
365 return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
368 static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
370 static ssize_t wakeup_total_time_show(struct device *dev,
371 struct device_attribute *attr, char *buf)
374 bool enabled = false;
376 spin_lock_irq(&dev->power.lock);
377 if (dev->power.wakeup) {
378 msec = ktime_to_ms(dev->power.wakeup->total_time);
381 spin_unlock_irq(&dev->power.lock);
382 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
385 static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
387 static ssize_t wakeup_max_time_show(struct device *dev,
388 struct device_attribute *attr, char *buf)
391 bool enabled = false;
393 spin_lock_irq(&dev->power.lock);
394 if (dev->power.wakeup) {
395 msec = ktime_to_ms(dev->power.wakeup->max_time);
398 spin_unlock_irq(&dev->power.lock);
399 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
402 static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
404 static ssize_t wakeup_last_time_show(struct device *dev,
405 struct device_attribute *attr, char *buf)
408 bool enabled = false;
410 spin_lock_irq(&dev->power.lock);
411 if (dev->power.wakeup) {
412 msec = ktime_to_ms(dev->power.wakeup->last_time);
415 spin_unlock_irq(&dev->power.lock);
416 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
419 static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
421 #ifdef CONFIG_PM_AUTOSLEEP
422 static ssize_t wakeup_prevent_sleep_time_show(struct device *dev,
423 struct device_attribute *attr,
427 bool enabled = false;
429 spin_lock_irq(&dev->power.lock);
430 if (dev->power.wakeup) {
431 msec = ktime_to_ms(dev->power.wakeup->prevent_sleep_time);
434 spin_unlock_irq(&dev->power.lock);
435 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
438 static DEVICE_ATTR(wakeup_prevent_sleep_time_ms, 0444,
439 wakeup_prevent_sleep_time_show, NULL);
440 #endif /* CONFIG_PM_AUTOSLEEP */
441 #endif /* CONFIG_PM_SLEEP */
443 #ifdef CONFIG_PM_ADVANCED_DEBUG
444 #ifdef CONFIG_PM_RUNTIME
446 static ssize_t rtpm_usagecount_show(struct device *dev,
447 struct device_attribute *attr, char *buf)
449 return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
452 static ssize_t rtpm_children_show(struct device *dev,
453 struct device_attribute *attr, char *buf)
455 return sprintf(buf, "%d\n", dev->power.ignore_children ?
456 0 : atomic_read(&dev->power.child_count));
459 static ssize_t rtpm_enabled_show(struct device *dev,
460 struct device_attribute *attr, char *buf)
462 if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
463 return sprintf(buf, "disabled & forbidden\n");
464 else if (dev->power.disable_depth)
465 return sprintf(buf, "disabled\n");
466 else if (dev->power.runtime_auto == false)
467 return sprintf(buf, "forbidden\n");
468 return sprintf(buf, "enabled\n");
471 static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
472 static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
473 static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);
477 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
480 return sprintf(buf, "%s\n",
481 device_async_suspend_enabled(dev) ? enabled : disabled);
484 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
485 const char *buf, size_t n)
490 cp = memchr(buf, '\n', n);
493 if (len == sizeof enabled - 1 && strncmp(buf, enabled, len) == 0)
494 device_enable_async_suspend(dev);
495 else if (len == sizeof disabled - 1 && strncmp(buf, disabled, len) == 0)
496 device_disable_async_suspend(dev);
502 static DEVICE_ATTR(async, 0644, async_show, async_store);
503 #endif /* CONFIG_PM_ADVANCED_DEBUG */
505 static struct attribute *power_attrs[] = {
506 #ifdef CONFIG_PM_ADVANCED_DEBUG
507 #ifdef CONFIG_PM_SLEEP
508 &dev_attr_async.attr,
510 #ifdef CONFIG_PM_RUNTIME
511 &dev_attr_runtime_status.attr,
512 &dev_attr_runtime_usage.attr,
513 &dev_attr_runtime_active_kids.attr,
514 &dev_attr_runtime_enabled.attr,
516 #endif /* CONFIG_PM_ADVANCED_DEBUG */
519 static struct attribute_group pm_attr_group = {
520 .name = power_group_name,
521 .attrs = power_attrs,
524 static struct attribute *wakeup_attrs[] = {
525 #ifdef CONFIG_PM_SLEEP
526 &dev_attr_wakeup.attr,
527 &dev_attr_wakeup_count.attr,
528 &dev_attr_wakeup_active_count.attr,
529 &dev_attr_wakeup_abort_count.attr,
530 &dev_attr_wakeup_expire_count.attr,
531 &dev_attr_wakeup_active.attr,
532 &dev_attr_wakeup_total_time_ms.attr,
533 &dev_attr_wakeup_max_time_ms.attr,
534 &dev_attr_wakeup_last_time_ms.attr,
535 #ifdef CONFIG_PM_AUTOSLEEP
536 &dev_attr_wakeup_prevent_sleep_time_ms.attr,
541 static struct attribute_group pm_wakeup_attr_group = {
542 .name = power_group_name,
543 .attrs = wakeup_attrs,
546 static struct attribute *runtime_attrs[] = {
547 #ifdef CONFIG_PM_RUNTIME
548 #ifndef CONFIG_PM_ADVANCED_DEBUG
549 &dev_attr_runtime_status.attr,
551 &dev_attr_control.attr,
552 &dev_attr_runtime_suspended_time.attr,
553 &dev_attr_runtime_active_time.attr,
554 &dev_attr_autosuspend_delay_ms.attr,
555 #endif /* CONFIG_PM_RUNTIME */
558 static struct attribute_group pm_runtime_attr_group = {
559 .name = power_group_name,
560 .attrs = runtime_attrs,
563 static struct attribute *pm_qos_attrs[] = {
564 #ifdef CONFIG_PM_RUNTIME
565 &dev_attr_pm_qos_resume_latency_us.attr,
566 #endif /* CONFIG_PM_RUNTIME */
569 static struct attribute_group pm_qos_attr_group = {
570 .name = power_group_name,
571 .attrs = pm_qos_attrs,
574 int dpm_sysfs_add(struct device *dev)
578 rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
582 if (pm_runtime_callbacks_present(dev)) {
583 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
588 if (device_can_wakeup(dev)) {
589 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
591 if (pm_runtime_callbacks_present(dev))
592 sysfs_unmerge_group(&dev->kobj,
593 &pm_runtime_attr_group);
600 sysfs_remove_group(&dev->kobj, &pm_attr_group);
604 int wakeup_sysfs_add(struct device *dev)
606 return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
609 void wakeup_sysfs_remove(struct device *dev)
611 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
614 int pm_qos_sysfs_add(struct device *dev)
616 return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group);
619 void pm_qos_sysfs_remove(struct device *dev)
621 sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group);
624 void rpm_sysfs_remove(struct device *dev)
626 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
629 void dpm_sysfs_remove(struct device *dev)
631 rpm_sysfs_remove(dev);
632 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
633 sysfs_remove_group(&dev->kobj, &pm_attr_group);