- 根目录:
- drivers
- base
- power
- sysfs.c
/*
* 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 (kstrtol(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_pm_qos_requested_latency(dev));
}
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.qos->latency_req, value);
return ret < 0 ? ret : n;
}
static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
pm_qos_latency_show, pm_qos_latency_store);
static ssize_t pm_qos_no_power_off_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
& PM_QOS_FLAG_NO_POWER_OFF));
}
static ssize_t pm_qos_no_power_off_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t n)
{
int ret;
if (kstrtoint(buf, 0, &ret))
return -EINVAL;
if (ret != 0 && ret != 1)
return -EINVAL;
ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_NO_POWER_OFF, ret);
return ret < 0 ? ret : n;
}
static DEVICE_ATTR(pm_qos_no_power_off, 0644,
pm_qos_no_power_off_show, pm_qos_no_power_off_store);
static ssize_t pm_qos_remote_wakeup_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev)
& PM_QOS_FLAG_REMOTE_WAKEUP));
}
static ssize_t pm_qos_remote_wakeup_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t n)
{
int ret;
if (kstrtoint(buf, 0, &ret))
return -EINVAL;
if (ret != 0 && ret != 1)
return -EINVAL;
ret = dev_pm_qos_update_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP, ret);
return ret < 0 ? ret : n;
}
static DEVICE_ATTR(pm_qos_remote_wakeup, 0644,
pm_qos_remote_wakeup_show, pm_qos_remote_wakeup_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_abort_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->wakeup_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_abort_count, 0444, wakeup_abort_count_show, NULL);
static ssize_t wakeup_expire_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->expire_count;
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_expire_count, 0444, wakeup_expire_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);
#ifdef CONFIG_PM_AUTOSLEEP
static ssize_t wakeup_prevent_sleep_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->prevent_sleep_time);
enabled = true;
}
spin_unlock_irq(&dev->power.lock);
return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
}
static DEVICE_ATTR(wakeup_prevent_sleep_time_ms, 0444,
wakeup_prevent_sleep_time_show, NULL);
#endif /* CONFIG_PM_AUTOSLEEP */
#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
#ifdef CONFIG_PM_SLEEP
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
#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_abort_count.attr,
&dev_attr_wakeup_expire_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,
#ifdef CONFIG_PM_AUTOSLEEP
&dev_attr_wakeup_prevent_sleep_time_ms.attr,
#endif
#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_latency_attrs[] = {
#ifdef CONFIG_PM_RUNTIME
&dev_attr_pm_qos_resume_latency_us.attr,
#endif /* CONFIG_PM_RUNTIME */
NULL,
};
static struct attribute_group pm_qos_latency_attr_group = {
.name = power_group_name,
.attrs = pm_qos_latency_attrs,
};
static struct attribute *pm_qos_flags_attrs[] = {
#ifdef CONFIG_PM_RUNTIME
&dev_attr_pm_qos_no_power_off.attr,
&dev_attr_pm_qos_remote_wakeup.attr,
#endif /* CONFIG_PM_RUNTIME */
NULL,
};
static struct attribute_group pm_qos_flags_attr_group = {
.name = power_group_name,
.attrs = pm_qos_flags_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_latency(struct device *dev)
{
return sysfs_merge_group(&dev->kobj, &pm_qos_latency_attr_group);
}
void pm_qos_sysfs_remove_latency(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_attr_group);
}
int pm_qos_sysfs_add_flags(struct device *dev)
{
return sysfs_merge_group(&dev->kobj, &pm_qos_flags_attr_group);
}
void pm_qos_sysfs_remove_flags(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &pm_qos_flags_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)
{
dev_pm_qos_constraints_destroy(dev);
rpm_sysfs_remove(dev);
sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
sysfs_remove_group(&dev->kobj, &pm_attr_group);
}