82 строки
1.7 KiB
C
82 строки
1.7 KiB
C
/*
|
|
* drivers/base/power/runtime.c - Handling dynamic device power management.
|
|
*
|
|
* Copyright (c) 2003 Patrick Mochel
|
|
* Copyright (c) 2003 Open Source Development Lab
|
|
*
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include "power.h"
|
|
|
|
|
|
static void runtime_resume(struct device * dev)
|
|
{
|
|
dev_dbg(dev, "resuming\n");
|
|
if (!dev->power.power_state)
|
|
return;
|
|
if (!resume_device(dev))
|
|
dev->power.power_state = 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* dpm_runtime_resume - Power one device back on.
|
|
* @dev: Device.
|
|
*
|
|
* Bring one device back to the on state by first powering it
|
|
* on, then restoring state. We only operate on devices that aren't
|
|
* already on.
|
|
* FIXME: We need to handle devices that are in an unknown state.
|
|
*/
|
|
|
|
void dpm_runtime_resume(struct device * dev)
|
|
{
|
|
down(&dpm_sem);
|
|
runtime_resume(dev);
|
|
up(&dpm_sem);
|
|
}
|
|
|
|
|
|
/**
|
|
* dpm_runtime_suspend - Put one device in low-power state.
|
|
* @dev: Device.
|
|
* @state: State to enter.
|
|
*/
|
|
|
|
int dpm_runtime_suspend(struct device * dev, pm_message_t state)
|
|
{
|
|
int error = 0;
|
|
|
|
down(&dpm_sem);
|
|
if (dev->power.power_state == state)
|
|
goto Done;
|
|
|
|
if (dev->power.power_state)
|
|
runtime_resume(dev);
|
|
|
|
if (!(error = suspend_device(dev, state)))
|
|
dev->power.power_state = state;
|
|
Done:
|
|
up(&dpm_sem);
|
|
return error;
|
|
}
|
|
|
|
|
|
/**
|
|
* dpm_set_power_state - Update power_state field.
|
|
* @dev: Device.
|
|
* @state: Power state device is in.
|
|
*
|
|
* This is an update mechanism for drivers to notify the core
|
|
* what power state a device is in. Device probing code may not
|
|
* always be able to tell, but we need accurate information to
|
|
* work reliably.
|
|
*/
|
|
void dpm_set_power_state(struct device * dev, pm_message_t state)
|
|
{
|
|
down(&dpm_sem);
|
|
dev->power.power_state = state;
|
|
up(&dpm_sem);
|
|
}
|