summaryrefslogtreecommitdiffstats
path: root/drivers/base/power/sysfs.c
blob: 95c12f6cb5b90da6257b95f839da60bfe3235c97 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
/*
 * drivers/base/power/sysfs.c - sysfs entries for device PM
 */

#include <linux/device.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/pm_qos.h>
#include <linux/pm_runtime.h>
#include <linux/atomic.h>
#include <linux/jiffies.h>
#include "power.h"

/*
 *	control - Report/change current runtime PM setting of the device
 *
 *	Runtime power management of a device can be blocked with the help of
 *	this attribute.  All devices have one of the following two values for
 *	the power/control file:
 *
 *	 + "auto\n" to allow the device to be power managed at run time;
 *	 + "on\n" to prevent the device from being power managed at run time;
 *
 *	The default for all devices is "auto", which means that devices may be
 *	subject to automatic power management, depending on their drivers.
 *	Changing this attribute to "on" prevents the driver from power managing
 *	the device at run time.  Doing that while the device is suspended causes
 *	it to be woken up.
 *
 *	wakeup - Report/change current wakeup option for device
 *
 *	Some devices support "wakeup" events, which are hardware signals
 *	used to activate devices from suspended or low power states.  Such
 *	devices have one of three values for the sysfs power/wakeup file:
 *
 *	 + "enabled\n" to issue the events;
 *	 + "disabled\n" not to do so; or
 *	 + "\n" for temporary or permanent inability to issue wakeup.
 *
 *	(For example, unconfigured USB devices can't issue wakeups.)
 *
 *	Familiar examples of devices that can issue wakeup events include
 *	keyboards and mice (both PS2 and USB styles), power buttons, modems,
 *	"Wake-On-LAN" Ethernet links, GPIO lines, and more.  Some events
 *	will wake the entire system from a suspend state; others may just
 *	wake up the device (if the system as a whole is already active).
 *	Some wakeup events use normal IRQ lines; other use special out
 *	of band signaling.
 *
 *	It is the responsibility of device drivers to enable (or disable)
 *	wakeup signaling as part of changing device power states, respecting
 *	the policy choices provided through the driver model.
 *
 *	Devices may not be able to generate wakeup events from all power
 *	states.  Also, the events may be ignored in some configurations;
 *	for example, they might need help from other devices that aren't
 *	active, or which may have wakeup disabled.  Some drivers rely on
 *	wakeup events internally (unless they are disabled), keeping
 *	their hardware in low power modes whenever they're unused.  This
 *	saves runtime power, without requiring system-wide sleep states.
 *
 *	async - Report/change current async suspend setting for the device
 *
 *	Asynchronous suspend and resume of the device during system-wide power
 *	state transitions can be enabled by writing "enabled" to this file.
 *	Analogously, if "disabled" is written to this file, the device will be
 *	suspended and resumed synchronously.
 *
 *	All devices have one of the following two values for power/async:
 *
 *	 + "enabled\n" to permit the asynchronous suspend/resume of the device;
 *	 + "disabled\n" to forbid it;
 *
 *	NOTE: It generally is unsafe to permit the asynchronous suspend/resume
 *	of a device unless it is certain that all of the PM dependencies of the
 *	device are known to the PM core.  However, for some devices this
 *	attribute is set to "enabled" by bus type code or device drivers and in
 *	that cases it should be safe to leave the default value.
 *
 *	autosuspend_delay_ms - Report/change a device's autosuspend_delay value
 *
 *	Some drivers don't want to carry out a runtime suspend as soon as a
 *	device becomes idle; they want it always to remain idle for some period
 *	of time before suspending it.  This period is the autosuspend_delay
 *	value (expressed in milliseconds) and it can be controlled by the user.
 *	If the value is negative then the device will never be runtime
 *	suspended.
 *
 *	NOTE: The autosuspend_delay_ms attribute and the autosuspend_delay
 *	value are used only if the driver calls pm_runtime_use_autosuspend().
 *
 *	wakeup_count - Report the number of wakeup events related to the device
 */

static const char enabled[] = "enabled";
static const char disabled[] = "disabled";

const char power_group_name[] = "power";
EXPORT_SYMBOL_GPL(power_group_name);

#ifdef CONFIG_PM_RUNTIME
static const char ctrl_auto[] = "auto";
static const char ctrl_on[] = "on";

static ssize_t control_show(struct device *dev, struct device_attribute *attr,
			    char *buf)
{
	return sprintf(buf, "%s\n",
				dev->power.runtime_auto ? ctrl_auto : ctrl_on);
}

static ssize_t control_store(struct device * dev, struct device_attribute *attr,
			     const char * buf, size_t n)
{
	char *cp;
	int len = n;

	cp = memchr(buf, '\n', n);
	if (cp)
		len = cp - buf;
	device_lock(dev);
	if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
		pm_runtime_allow(dev);
	else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
		pm_runtime_forbid(dev);
	else
		n = -EINVAL;
	device_unlock(dev);
	return n;
}

static DEVICE_ATTR(control, 0644, control_show, control_store);

static ssize_t rtpm_active_time_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	int ret;
	spin_lock_irq(&dev->power.lock);
	update_pm_runtime_accounting(dev);
	ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies));
	spin_unlock_irq(&dev->power.lock);
	return ret;
}

static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);

static ssize_t rtpm_suspended_time_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	int ret;
	spin_lock_irq(&dev->power.lock);
	update_pm_runtime_accounting(dev);
	ret = sprintf(buf, "%i\n",
		jiffies_to_msecs(dev->power.suspended_jiffies));
	spin_unlock_irq(&dev->power.lock);
	return ret;
}

static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);

static ssize_t rtpm_status_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	const char *p;

	if (dev->power.runtime_error) {
		p = "error\n";
	} else if (dev->power.disable_depth) {
		p = "unsupported\n";
	} else {
		switch (dev->power.runtime_status) {
		case RPM_SUSPENDED:
			p = "suspended\n";
			break;
		case RPM_SUSPENDING:
			p = "suspending\n";
			break;
		case RPM_RESUMING:
			p = "resuming\n";
			break;
		case RPM_ACTIVE:
			p = "active\n";
			break;
		default:
			return -EIO;
		}
	}
	return sprintf(buf, p);
}

static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);

static ssize_t autosuspend_delay_ms_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	if (!dev->power.use_autosuspend)
		return -EIO;
	return sprintf(buf, "%d\n", dev->power.autosuspend_delay);
}

static ssize_t autosuspend_delay_ms_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t n)
{
	long delay;

	if (!dev->power.use_autosuspend)
		return -EIO;

	if (strict_strtol(buf, 10, &delay) != 0 || delay != (int) delay)
		return -EINVAL;

	device_lock(dev);
	pm_runtime_set_autosuspend_delay(dev, delay);
	device_unlock(dev);
	return n;
}

static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
		autosuspend_delay_ms_store);

static ssize_t pm_qos_latency_show(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", dev->power.pq_req->node.prio);
}

static ssize_t pm_qos_latency_store(struct device *dev,
				    struct device_attribute *attr,
				    const char *buf, size_t n)
{
	s32 value;
	int ret;

	if (kstrtos32(buf, 0, &value))
		return -EINVAL;

	if (value < 0)
		return -EINVAL;

	ret = dev_pm_qos_update_request(dev->power.pq_req, value);
	return ret < 0 ? ret : n;
}

static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
		   pm_qos_latency_show, pm_qos_latency_store);
#endif /* CONFIG_PM_RUNTIME */

#ifdef CONFIG_PM_SLEEP
static ssize_t
wake_show(struct device * dev, struct device_attribute *attr, char * buf)
{
	return sprintf(buf, "%s\n", device_can_wakeup(dev)
		? (device_may_wakeup(dev) ? enabled : disabled)
		: "");
}

static ssize_t
wake_store(struct device * dev, struct device_attribute *attr,
	const char * buf, size_t n)
{
	char *cp;
	int len = n;

	if (!device_can_wakeup(dev))
		return -EINVAL;

	cp = memchr(buf, '\n', n);
	if (cp)
		len = cp - buf;
	if (len == sizeof enabled - 1
			&& strncmp(buf, enabled, sizeof enabled - 1) == 0)
		device_set_wakeup_enable(dev, 1);
	else if (len == sizeof disabled - 1
			&& strncmp(buf, disabled, sizeof disabled - 1) == 0)
		device_set_wakeup_enable(dev, 0);
	else
		return -EINVAL;
	return n;
}

static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);

static ssize_t wakeup_count_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	unsigned long count = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		count = dev->power.wakeup->event_count;
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);

static ssize_t wakeup_active_count_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	unsigned long count = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		count = dev->power.wakeup->active_count;
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);

static ssize_t wakeup_hit_count_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	unsigned long count = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		count = dev->power.wakeup->hit_count;
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_hit_count, 0444, wakeup_hit_count_show, NULL);

static ssize_t wakeup_active_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	unsigned int active = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		active = dev->power.wakeup->active;
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);

static ssize_t wakeup_total_time_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	s64 msec = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		msec = ktime_to_ms(dev->power.wakeup->total_time);
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);

static ssize_t wakeup_max_time_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	s64 msec = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		msec = ktime_to_ms(dev->power.wakeup->max_time);
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);

static ssize_t wakeup_last_time_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	s64 msec = 0;
	bool enabled = false;

	spin_lock_irq(&dev->power.lock);
	if (dev->power.wakeup) {
		msec = ktime_to_ms(dev->power.wakeup->last_time);
		enabled = true;
	}
	spin_unlock_irq(&dev->power.lock);
	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}

static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM_ADVANCED_DEBUG
#ifdef CONFIG_PM_RUNTIME

static ssize_t rtpm_usagecount_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
}

static ssize_t rtpm_children_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", dev->power.ignore_children ?
		0 : atomic_read(&dev->power.child_count));
}

static ssize_t rtpm_enabled_show(struct device *dev,
				 struct device_attribute *attr, char *buf)
{
	if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
		return sprintf(buf, "disabled & forbidden\n");
	else if (dev->power.disable_depth)
		return sprintf(buf, "disabled\n");
	else if (dev->power.runtime_auto == false)
		return sprintf(buf, "forbidden\n");
	return sprintf(buf, "enabled\n");
}

static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);

#endif

static ssize_t async_show(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	return sprintf(buf, "%s\n",
			device_async_suspend_enabled(dev) ? enabled : disabled);
}

static ssize_t async_store(struct device *dev, struct device_attribute *attr,
			   const char *buf, size_t n)
{
	char *cp;
	int len = n;

	cp = memchr(buf, '\n', n);
	if (cp)
		len = cp - buf;
	if (len == sizeof enabled - 1 && strncmp(buf, enabled, len) == 0)
		device_enable_async_suspend(dev);
	else if (len == sizeof disabled - 1 && strncmp(buf, disabled, len) == 0)
		device_disable_async_suspend(dev);
	else
		return -EINVAL;
	return n;
}

static DEVICE_ATTR(async, 0644, async_show, async_store);
#endif /* CONFIG_PM_ADVANCED_DEBUG */

static struct attribute *power_attrs[] = {
#ifdef CONFIG_PM_ADVANCED_DEBUG
#ifdef CONFIG_PM_SLEEP
	&dev_attr_async.attr,
#endif
#ifdef CONFIG_PM_RUNTIME
	&dev_attr_runtime_status.attr,
	&dev_attr_runtime_usage.attr,
	&dev_attr_runtime_active_kids.attr,
	&dev_attr_runtime_enabled.attr,
#endif
#endif /* CONFIG_PM_ADVANCED_DEBUG */
	NULL,
};
static struct attribute_group pm_attr_group = {
	.name	= power_group_name,
	.attrs	= power_attrs,
};

static struct attribute *wakeup_attrs[] = {
#ifdef CONFIG_PM_SLEEP
	&dev_attr_wakeup.attr,
	&dev_attr_wakeup_count.attr,
	&dev_attr_wakeup_active_count.attr,
	&dev_attr_wakeup_hit_count.attr,
	&dev_attr_wakeup_active.attr,
	&dev_attr_wakeup_total_time_ms.attr,
	&dev_attr_wakeup_max_time_ms.attr,
	&dev_attr_wakeup_last_time_ms.attr,
#endif
	NULL,
};
static struct attribute_group pm_wakeup_attr_group = {
	.name	= power_group_name,
	.attrs	= wakeup_attrs,
};

static struct attribute *runtime_attrs[] = {
#ifdef CONFIG_PM_RUNTIME
#ifndef CONFIG_PM_ADVANCED_DEBUG
	&dev_attr_runtime_status.attr,
#endif
	&dev_attr_control.attr,
	&dev_attr_runtime_suspended_time.attr,
	&dev_attr_runtime_active_time.attr,
	&dev_attr_autosuspend_delay_ms.attr,
#endif /* CONFIG_PM_RUNTIME */
	NULL,
};
static struct attribute_group pm_runtime_attr_group = {
	.name	= power_group_name,
	.attrs	= runtime_attrs,
};

static struct attribute *pm_qos_attrs[] = {
#ifdef CONFIG_PM_RUNTIME
	&dev_attr_pm_qos_resume_latency_us.attr,
#endif /* CONFIG_PM_RUNTIME */
	NULL,
};
static struct attribute_group pm_qos_attr_group = {
	.name	= power_group_name,
	.attrs	= pm_qos_attrs,
};

int dpm_sysfs_add(struct device *dev)
{
	int rc;

	rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
	if (rc)
		return rc;

	if (pm_runtime_callbacks_present(dev)) {
		rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
		if (rc)
			goto err_out;
	}

	if (device_can_wakeup(dev)) {
		rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
		if (rc) {
			if (pm_runtime_callbacks_present(dev))
				sysfs_unmerge_group(&dev->kobj,
						    &pm_runtime_attr_group);
			goto err_out;
		}
	}
	return 0;

 err_out:
	sysfs_remove_group(&dev->kobj, &pm_attr_group);
	return rc;
}

int wakeup_sysfs_add(struct device *dev)
{
	return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
}

void wakeup_sysfs_remove(struct device *dev)
{
	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
}

int pm_qos_sysfs_add(struct device *dev)
{
	return sysfs_merge_group(&dev->kobj, &pm_qos_attr_group);
}

void pm_qos_sysfs_remove(struct device *dev)
{
	sysfs_unmerge_group(&dev->kobj, &pm_qos_attr_group);
}

void rpm_sysfs_remove(struct device *dev)
{
	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
}

void dpm_sysfs_remove(struct device *dev)
{
	rpm_sysfs_remove(dev);
	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
	sysfs_remove_group(&dev->kobj, &pm_attr_group);
}
OpenPOWER on IntegriCloud