mirror of https://gitee.com/openkylin/linux.git
143 lines
4.3 KiB
C
143 lines
4.3 KiB
C
/*
|
|
* drivers/base/power/sysfs.c - sysfs entries for device PM
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/string.h>
|
|
#include "power.h"
|
|
|
|
|
|
/**
|
|
* state - Control current power state of device
|
|
*
|
|
* show() returns the current power state of the device. '0' indicates
|
|
* the device is on. Other values (1-3) indicate the device is in a low
|
|
* power state.
|
|
*
|
|
* store() sets the current power state, which is an integer value
|
|
* between 0-3. If the device is on ('0'), and the value written is
|
|
* greater than 0, then the device is placed directly into the low-power
|
|
* state (via its driver's ->suspend() method).
|
|
* If the device is currently in a low-power state, and the value is 0,
|
|
* the device is powered back on (via the ->resume() method).
|
|
* If the device is in a low-power state, and a different low-power state
|
|
* is requested, the device is first resumed, then suspended into the new
|
|
* low-power state.
|
|
*/
|
|
|
|
static ssize_t state_show(struct device * dev, struct device_attribute *attr, char * buf)
|
|
{
|
|
return sprintf(buf, "%u\n", dev->power.power_state.event);
|
|
}
|
|
|
|
static ssize_t state_store(struct device * dev, struct device_attribute *attr, const char * buf, size_t n)
|
|
{
|
|
pm_message_t state;
|
|
char * rest;
|
|
int error = 0;
|
|
|
|
state.event = simple_strtoul(buf, &rest, 10);
|
|
if (*rest)
|
|
return -EINVAL;
|
|
if (state.event)
|
|
error = dpm_runtime_suspend(dev, state);
|
|
else
|
|
dpm_runtime_resume(dev);
|
|
return error ? error : n;
|
|
}
|
|
|
|
static DEVICE_ATTR(state, 0644, state_show, state_store);
|
|
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
static const char enabled[] = "enabled";
|
|
static const char disabled[] = "disabled";
|
|
|
|
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 struct attribute * power_attrs[] = {
|
|
&dev_attr_state.attr,
|
|
&dev_attr_wakeup.attr,
|
|
NULL,
|
|
};
|
|
static struct attribute_group pm_attr_group = {
|
|
.name = "power",
|
|
.attrs = power_attrs,
|
|
};
|
|
|
|
int dpm_sysfs_add(struct device * dev)
|
|
{
|
|
return sysfs_create_group(&dev->kobj, &pm_attr_group);
|
|
}
|
|
|
|
void dpm_sysfs_remove(struct device * dev)
|
|
{
|
|
sysfs_remove_group(&dev->kobj, &pm_attr_group);
|
|
}
|