Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target...
[linux-btrfs-devel.git] / drivers / base / power / sysfs.c
blob17b7934f31cb00c014688d6d0e197886687c3730
1 /*
2 * drivers/base/power/sysfs.c - sysfs entries for device PM
3 */
5 #include <linux/device.h>
6 #include <linux/string.h>
7 #include <linux/pm_runtime.h>
8 #include <linux/atomic.h>
9 #include <linux/jiffies.h>
10 #include "power.h"
13 * control - Report/change current runtime PM setting of the device
15 * Runtime power management of a device can be blocked with the help of
16 * this attribute. All devices have one of the following two values for
17 * the power/control file:
19 * + "auto\n" to allow the device to be power managed at run time;
20 * + "on\n" to prevent the device from being power managed at run time;
22 * The default for all devices is "auto", which means that devices may be
23 * subject to automatic power management, depending on their drivers.
24 * Changing this attribute to "on" prevents the driver from power managing
25 * the device at run time. Doing that while the device is suspended causes
26 * it to be woken up.
28 * wakeup - Report/change current wakeup option for device
30 * Some devices support "wakeup" events, which are hardware signals
31 * used to activate devices from suspended or low power states. Such
32 * devices have one of three values for the sysfs power/wakeup file:
34 * + "enabled\n" to issue the events;
35 * + "disabled\n" not to do so; or
36 * + "\n" for temporary or permanent inability to issue wakeup.
38 * (For example, unconfigured USB devices can't issue wakeups.)
40 * Familiar examples of devices that can issue wakeup events include
41 * keyboards and mice (both PS2 and USB styles), power buttons, modems,
42 * "Wake-On-LAN" Ethernet links, GPIO lines, and more. Some events
43 * will wake the entire system from a suspend state; others may just
44 * wake up the device (if the system as a whole is already active).
45 * Some wakeup events use normal IRQ lines; other use special out
46 * of band signaling.
48 * It is the responsibility of device drivers to enable (or disable)
49 * wakeup signaling as part of changing device power states, respecting
50 * the policy choices provided through the driver model.
52 * Devices may not be able to generate wakeup events from all power
53 * states. Also, the events may be ignored in some configurations;
54 * for example, they might need help from other devices that aren't
55 * active, or which may have wakeup disabled. Some drivers rely on
56 * wakeup events internally (unless they are disabled), keeping
57 * their hardware in low power modes whenever they're unused. This
58 * saves runtime power, without requiring system-wide sleep states.
60 * async - Report/change current async suspend setting for the device
62 * Asynchronous suspend and resume of the device during system-wide power
63 * state transitions can be enabled by writing "enabled" to this file.
64 * Analogously, if "disabled" is written to this file, the device will be
65 * suspended and resumed synchronously.
67 * All devices have one of the following two values for power/async:
69 * + "enabled\n" to permit the asynchronous suspend/resume of the device;
70 * + "disabled\n" to forbid it;
72 * NOTE: It generally is unsafe to permit the asynchronous suspend/resume
73 * of a device unless it is certain that all of the PM dependencies of the
74 * device are known to the PM core. However, for some devices this
75 * attribute is set to "enabled" by bus type code or device drivers and in
76 * that cases it should be safe to leave the default value.
78 * autosuspend_delay_ms - Report/change a device's autosuspend_delay value
80 * Some drivers don't want to carry out a runtime suspend as soon as a
81 * device becomes idle; they want it always to remain idle for some period
82 * of time before suspending it. This period is the autosuspend_delay
83 * value (expressed in milliseconds) and it can be controlled by the user.
84 * If the value is negative then the device will never be runtime
85 * suspended.
87 * NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
88 * value are used only if the driver calls pm_runtime_use_autosuspend().
90 * wakeup_count - Report the number of wakeup events related to the device
93 static const char enabled[] = "enabled";
94 static const char disabled[] = "disabled";
96 const char power_group_name[] = "power";
97 EXPORT_SYMBOL_GPL(power_group_name);
99 #ifdef CONFIG_PM_RUNTIME
100 static const char ctrl_auto[] = "auto";
101 static const char ctrl_on[] = "on";
103 static ssize_t control_show(struct device *dev, struct device_attribute *attr,
104 char *buf)
106 return sprintf(buf, "%s\n",
107 dev->power.runtime_auto ? ctrl_auto : ctrl_on);
110 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
111 const char * buf, size_t n)
113 char *cp;
114 int len = n;
116 cp = memchr(buf, '\n', n);
117 if (cp)
118 len = cp - buf;
119 device_lock(dev);
120 if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
121 pm_runtime_allow(dev);
122 else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
123 pm_runtime_forbid(dev);
124 else
125 n = -EINVAL;
126 device_unlock(dev);
127 return n;
130 static DEVICE_ATTR(control, 0644, control_show, control_store);
132 static ssize_t rtpm_active_time_show(struct device *dev,
133 struct device_attribute *attr, char *buf)
135 int ret;
136 spin_lock_irq(&dev->power.lock);
137 update_pm_runtime_accounting(dev);
138 ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
139 spin_unlock_irq(&dev->power.lock);
140 return ret;
143 static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
145 static ssize_t rtpm_suspended_time_show(struct device *dev,
146 struct device_attribute *attr, char *buf)
148 int ret;
149 spin_lock_irq(&dev->power.lock);
150 update_pm_runtime_accounting(dev);
151 ret = sprintf(buf, "%i\n",
152 jiffies_to_msecs(dev->power.suspended_jiffies));
153 spin_unlock_irq(&dev->power.lock);
154 return ret;
157 static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
159 static ssize_t rtpm_status_show(struct device *dev,
160 struct device_attribute *attr, char *buf)
162 const char *p;
164 if (dev->power.runtime_error) {
165 p = "error\n";
166 } else if (dev->power.disable_depth) {
167 p = "unsupported\n";
168 } else {
169 switch (dev->power.runtime_status) {
170 case RPM_SUSPENDED:
171 p = "suspended\n";
172 break;
173 case RPM_SUSPENDING:
174 p = "suspending\n";
175 break;
176 case RPM_RESUMING:
177 p = "resuming\n";
178 break;
179 case RPM_ACTIVE:
180 p = "active\n";
181 break;
182 default:
183 return -EIO;
186 return sprintf(buf, p);
189 static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
191 static ssize_t autosuspend_delay_ms_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
194 if (!dev->power.use_autosuspend)
195 return -EIO;
196 return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
199 static ssize_t autosuspend_delay_ms_store(struct device *dev,
200 struct device_attribute *attr, const char *buf, size_t n)
202 long delay;
204 if (!dev->power.use_autosuspend)
205 return -EIO;
207 if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
208 return -EINVAL;
210 device_lock(dev);
211 pm_runtime_set_autosuspend_delay(dev, delay);
212 device_unlock(dev);
213 return n;
216 static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
217 autosuspend_delay_ms_store);
219 #endif /* CONFIG_PM_RUNTIME */
221 #ifdef CONFIG_PM_SLEEP
222 static ssize_t
223 wake_show(struct device * dev, struct device_attribute *attr, char * buf)
225 return sprintf(buf, "%s\n", device_can_wakeup(dev)
226 ? (device_may_wakeup(dev) ? enabled : disabled)
227 : "");
230 static ssize_t
231 wake_store(struct device * dev, struct device_attribute *attr,
232 const char * buf, size_t n)
234 char *cp;
235 int len = n;
237 if (!device_can_wakeup(dev))
238 return -EINVAL;
240 cp = memchr(buf, '\n', n);
241 if (cp)
242 len = cp - buf;
243 if (len == sizeof enabled - 1
244 && strncmp(buf, enabled, sizeof enabled - 1) == 0)
245 device_set_wakeup_enable(dev, 1);
246 else if (len == sizeof disabled - 1
247 && strncmp(buf, disabled, sizeof disabled - 1) == 0)
248 device_set_wakeup_enable(dev, 0);
249 else
250 return -EINVAL;
251 return n;
254 static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
256 static ssize_t wakeup_count_show(struct device *dev,
257 struct device_attribute *attr, char *buf)
259 unsigned long count = 0;
260 bool enabled = false;
262 spin_lock_irq(&dev->power.lock);
263 if (dev->power.wakeup) {
264 count = dev->power.wakeup->event_count;
265 enabled = true;
267 spin_unlock_irq(&dev->power.lock);
268 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
271 static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
273 static ssize_t wakeup_active_count_show(struct device *dev,
274 struct device_attribute *attr, char *buf)
276 unsigned long count = 0;
277 bool enabled = false;
279 spin_lock_irq(&dev->power.lock);
280 if (dev->power.wakeup) {
281 count = dev->power.wakeup->active_count;
282 enabled = true;
284 spin_unlock_irq(&dev->power.lock);
285 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
288 static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
290 static ssize_t wakeup_hit_count_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
293 unsigned long count = 0;
294 bool enabled = false;
296 spin_lock_irq(&dev->power.lock);
297 if (dev->power.wakeup) {
298 count = dev->power.wakeup->hit_count;
299 enabled = true;
301 spin_unlock_irq(&dev->power.lock);
302 return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
305 static DEVICE_ATTR(wakeup_hit_count, 0444, wakeup_hit_count_show, NULL);
307 static ssize_t wakeup_active_show(struct device *dev,
308 struct device_attribute *attr, char *buf)
310 unsigned int active = 0;
311 bool enabled = false;
313 spin_lock_irq(&dev->power.lock);
314 if (dev->power.wakeup) {
315 active = dev->power.wakeup->active;
316 enabled = true;
318 spin_unlock_irq(&dev->power.lock);
319 return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
322 static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
324 static ssize_t wakeup_total_time_show(struct device *dev,
325 struct device_attribute *attr, char *buf)
327 s64 msec = 0;
328 bool enabled = false;
330 spin_lock_irq(&dev->power.lock);
331 if (dev->power.wakeup) {
332 msec = ktime_to_ms(dev->power.wakeup->total_time);
333 enabled = true;
335 spin_unlock_irq(&dev->power.lock);
336 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
339 static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
341 static ssize_t wakeup_max_time_show(struct device *dev,
342 struct device_attribute *attr, char *buf)
344 s64 msec = 0;
345 bool enabled = false;
347 spin_lock_irq(&dev->power.lock);
348 if (dev->power.wakeup) {
349 msec = ktime_to_ms(dev->power.wakeup->max_time);
350 enabled = true;
352 spin_unlock_irq(&dev->power.lock);
353 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
356 static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
358 static ssize_t wakeup_last_time_show(struct device *dev,
359 struct device_attribute *attr, char *buf)
361 s64 msec = 0;
362 bool enabled = false;
364 spin_lock_irq(&dev->power.lock);
365 if (dev->power.wakeup) {
366 msec = ktime_to_ms(dev->power.wakeup->last_time);
367 enabled = true;
369 spin_unlock_irq(&dev->power.lock);
370 return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
373 static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
374 #endif /* CONFIG_PM_SLEEP */
376 #ifdef CONFIG_PM_ADVANCED_DEBUG
377 #ifdef CONFIG_PM_RUNTIME
379 static ssize_t rtpm_usagecount_show(struct device *dev,
380 struct device_attribute *attr, char *buf)
382 return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
385 static ssize_t rtpm_children_show(struct device *dev,
386 struct device_attribute *attr, char *buf)
388 return sprintf(buf, "%d\n", dev->power.ignore_children ?
389 0 : atomic_read(&dev->power.child_count));
392 static ssize_t rtpm_enabled_show(struct device *dev,
393 struct device_attribute *attr, char *buf)
395 if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
396 return sprintf(buf, "disabled & forbidden\n");
397 else if (dev->power.disable_depth)
398 return sprintf(buf, "disabled\n");
399 else if (dev->power.runtime_auto == false)
400 return sprintf(buf, "forbidden\n");
401 return sprintf(buf, "enabled\n");
404 static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
405 static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
406 static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);
408 #endif
410 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
411 char *buf)
413 return sprintf(buf, "%s\n",
414 device_async_suspend_enabled(dev) ? enabled : disabled);
417 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
418 const char *buf, size_t n)
420 char *cp;
421 int len = n;
423 cp = memchr(buf, '\n', n);
424 if (cp)
425 len = cp - buf;
426 if (len == sizeof enabled - 1 && strncmp(buf, enabled, len) == 0)
427 device_enable_async_suspend(dev);
428 else if (len == sizeof disabled - 1 && strncmp(buf, disabled, len) == 0)
429 device_disable_async_suspend(dev);
430 else
431 return -EINVAL;
432 return n;
435 static DEVICE_ATTR(async, 0644, async_show, async_store);
436 #endif /* CONFIG_PM_ADVANCED_DEBUG */
438 static struct attribute *power_attrs[] = {
439 #ifdef CONFIG_PM_ADVANCED_DEBUG
440 #ifdef CONFIG_PM_SLEEP
441 &dev_attr_async.attr,
442 #endif
443 #ifdef CONFIG_PM_RUNTIME
444 &dev_attr_runtime_status.attr,
445 &dev_attr_runtime_usage.attr,
446 &dev_attr_runtime_active_kids.attr,
447 &dev_attr_runtime_enabled.attr,
448 #endif
449 #endif /* CONFIG_PM_ADVANCED_DEBUG */
450 NULL,
452 static struct attribute_group pm_attr_group = {
453 .name = power_group_name,
454 .attrs = power_attrs,
457 static struct attribute *wakeup_attrs[] = {
458 #ifdef CONFIG_PM_SLEEP
459 &dev_attr_wakeup.attr,
460 &dev_attr_wakeup_count.attr,
461 &dev_attr_wakeup_active_count.attr,
462 &dev_attr_wakeup_hit_count.attr,
463 &dev_attr_wakeup_active.attr,
464 &dev_attr_wakeup_total_time_ms.attr,
465 &dev_attr_wakeup_max_time_ms.attr,
466 &dev_attr_wakeup_last_time_ms.attr,
467 #endif
468 NULL,
470 static struct attribute_group pm_wakeup_attr_group = {
471 .name = power_group_name,
472 .attrs = wakeup_attrs,
475 static struct attribute *runtime_attrs[] = {
476 #ifdef CONFIG_PM_RUNTIME
477 #ifndef CONFIG_PM_ADVANCED_DEBUG
478 &dev_attr_runtime_status.attr,
479 #endif
480 &dev_attr_control.attr,
481 &dev_attr_runtime_suspended_time.attr,
482 &dev_attr_runtime_active_time.attr,
483 &dev_attr_autosuspend_delay_ms.attr,
484 #endif /* CONFIG_PM_RUNTIME */
485 NULL,
487 static struct attribute_group pm_runtime_attr_group = {
488 .name = power_group_name,
489 .attrs = runtime_attrs,
492 int dpm_sysfs_add(struct device *dev)
494 int rc;
496 rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
497 if (rc)
498 return rc;
500 if (pm_runtime_callbacks_present(dev)) {
501 rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
502 if (rc)
503 goto err_out;
506 if (device_can_wakeup(dev)) {
507 rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
508 if (rc) {
509 if (pm_runtime_callbacks_present(dev))
510 sysfs_unmerge_group(&dev->kobj,
511 &pm_runtime_attr_group);
512 goto err_out;
515 return 0;
517 err_out:
518 sysfs_remove_group(&dev->kobj, &pm_attr_group);
519 return rc;
522 int wakeup_sysfs_add(struct device *dev)
524 return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
527 void wakeup_sysfs_remove(struct device *dev)
529 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
532 void rpm_sysfs_remove(struct device *dev)
534 sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
537 void dpm_sysfs_remove(struct device *dev)
539 rpm_sysfs_remove(dev);
540 sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
541 sysfs_remove_group(&dev->kobj, &pm_attr_group);