mirror of https://gitee.com/openkylin/linux.git
79 lines
2.3 KiB
C
79 lines
2.3 KiB
C
/*
|
|
* drivers/base/power/main.c - Where the driver meets power management.
|
|
*
|
|
* Copyright (c) 2003 Patrick Mochel
|
|
* Copyright (c) 2003 Open Source Development Lab
|
|
*
|
|
* This file is released under the GPLv2
|
|
*
|
|
*
|
|
* The driver model core calls device_pm_add() when a device is registered.
|
|
* This will intialize the embedded device_pm_info object in the device
|
|
* and add it to the list of power-controlled devices. sysfs entries for
|
|
* controlling device power management will also be added.
|
|
*
|
|
* A different set of lists than the global subsystem list are used to
|
|
* keep track of power info because we use different lists to hold
|
|
* devices based on what stage of the power management process they
|
|
* are in. The power domain dependencies may also differ from the
|
|
* ancestral dependencies that the subsystem list maintains.
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include "power.h"
|
|
|
|
LIST_HEAD(dpm_active);
|
|
LIST_HEAD(dpm_off);
|
|
LIST_HEAD(dpm_off_irq);
|
|
|
|
DECLARE_MUTEX(dpm_sem);
|
|
DECLARE_MUTEX(dpm_list_sem);
|
|
|
|
/**
|
|
* device_pm_set_parent - Specify power dependency.
|
|
* @dev: Device who needs power.
|
|
* @parent: Device that supplies power.
|
|
*
|
|
* This function is used to manually describe a power-dependency
|
|
* relationship. It may be used to specify a transversal relationship
|
|
* (where the power supplier is not the physical (or electrical)
|
|
* ancestor of a specific device.
|
|
* The effect of this is that the supplier will not be powered down
|
|
* before the power dependent.
|
|
*/
|
|
|
|
void device_pm_set_parent(struct device * dev, struct device * parent)
|
|
{
|
|
put_device(dev->power.pm_parent);
|
|
dev->power.pm_parent = get_device(parent);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_pm_set_parent);
|
|
|
|
int device_pm_add(struct device * dev)
|
|
{
|
|
int error;
|
|
|
|
pr_debug("PM: Adding info for %s:%s\n",
|
|
dev->bus ? dev->bus->name : "No Bus", dev->kobj.name);
|
|
down(&dpm_list_sem);
|
|
list_add_tail(&dev->power.entry, &dpm_active);
|
|
device_pm_set_parent(dev, dev->parent);
|
|
if ((error = dpm_sysfs_add(dev)))
|
|
list_del(&dev->power.entry);
|
|
up(&dpm_list_sem);
|
|
return error;
|
|
}
|
|
|
|
void device_pm_remove(struct device * dev)
|
|
{
|
|
pr_debug("PM: Removing info for %s:%s\n",
|
|
dev->bus ? dev->bus->name : "No Bus", dev->kobj.name);
|
|
down(&dpm_list_sem);
|
|
dpm_sysfs_remove(dev);
|
|
put_device(dev->power.pm_parent);
|
|
list_del_init(&dev->power.entry);
|
|
up(&dpm_list_sem);
|
|
}
|
|
|
|
|