shutdown.c

h内核

/*
 * shutdown.c - power management functions for the device tree.
 *
 * Copyright (c) 2002-3 Patrick Mochel
 *		 2002-3 Open Source Development Lab
 *
 * This file is released under the GPLv2
 *
 */

#include <linux/config.h>
#include <linux/device.h>
#include <asm/semaphore.h>

#include "power.h"

#define to_dev(node) container_of(node, struct device, kobj.entry)

extern struct subsystem devices_subsys;


int device_detach_shutdown(struct device * dev)
{
	if (!dev->detach_state)
		return 0;

	if (dev->detach_state == DEVICE_PM_OFF) {
		if (dev->driver && dev->driver->shutdown)
			dev->driver->shutdown(dev);
		return 0;
	}
	return dpm_runtime_suspend(dev, dev->detach_state);
}


/**
 * We handle system devices differently - we suspend and shut them
 * down last and resume them first. That way, we don't do anything stupid like
 * shutting down the interrupt controller before any devices..
 *
 * Note that there are not different stages for power management calls -
 * they only get one called once when interrupts are disabled.
 */

extern int sysdev_shutdown(void);

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
	struct device * dev;

	down_write(&devices_subsys.rwsem);
	list_for_each_entry_reverse(dev, &devices_subsys.kset.list, kobj.entry) {
		pr_debug("shutting down %s: ", dev->bus_id);
		if (dev->driver && dev->driver->shutdown) {
			pr_debug("Ok\n");
			dev->driver->shutdown(dev);
		} else
			pr_debug("Ignored.\n");
	}
	up_write(&devices_subsys.rwsem);

	sysdev_shutdown();
}