/* * drivers/base/interface.c - common driverfs interface that's exported to * 	the world for all devices. * * Copyright (c) 2002-3 Patrick Mochel * Copyright (c) 2002-3 Open Source Development Labs * * This file is released under the GPLv2 * */ #include <linux/device.h>#include <linux/err.h>#include <linux/stat.h>#include <linux/string.h> /** *	detach_state - control the default power state for the device. * *	This is the state the device enters when it's driver module is *	unloaded. The value is an unsigned integer, in the range of 0-4. *	'0' indicates 'On', so no action will be taken when the driver is *	unloaded. This is the default behavior. *	'4' indicates 'Off', meaning the driver core will call the driver's *	shutdown method to quiesce the device. *	1-3 indicate a low-power state for the device to enter via the *	driver's suspend method. */ static ssize_t detach_show(struct device * dev, char * buf){	return sprintf(buf, "%u\n", dev->detach_state);} static ssize_t detach_store(struct device * dev, const char * buf, size_t n){	u32 state;	state = simple_strtoul(buf, NULL, 10);	if (state > 4)		return -EINVAL;	dev->detach_state = state;	return n;} static DEVICE_ATTR(detach_state, 0644, detach_show, detach_store);  struct attribute * dev_default_attrs[] = {	&dev_attr_detach_state.attr,	NULL,};