sysfs.c

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/*
 * drivers/usb/core/sysfs.c
 *
 * (C) Copyright 2002 David Brownell
 * (C) Copyright 2002,2004 Greg Kroah-Hartman
 * (C) Copyright 2002,2004 IBM Corp.
 *
 * All of the sysfs file attributes for usb devices and interfaces.
 *
 */


#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/usb.h>
#include "usb.h"

/* Active configuration fields */
#define usb_actconfig_show(field, multiplier, format_string)		\
static ssize_t  show_##field(struct device *dev,			\
		struct device_attribute *attr, char *buf)		\
{									\
	struct usb_device *udev;					\
	struct usb_host_config *actconfig;				\
									\
	udev = to_usb_device(dev);					\
	actconfig = udev->actconfig;					\
	if (actconfig)							\
		return sprintf(buf, format_string,			\
				actconfig->desc.field * multiplier);	\
	else								\
		return 0;						\
}									\

#define usb_actconfig_attr(field, multiplier, format_string)		\
usb_actconfig_show(field, multiplier, format_string)			\
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);

usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
usb_actconfig_attr(bmAttributes, 1, "%2x\n")
usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")

static ssize_t show_configuration_string(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	struct usb_host_config *actconfig;

	udev = to_usb_device(dev);
	actconfig = udev->actconfig;
	if ((!actconfig) || (!actconfig->string))
		return 0;
	return sprintf(buf, "%s\n", actconfig->string);
}
static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);

/* configuration value is always present, and r/w */
usb_actconfig_show(bConfigurationValue, 1, "%u\n");

static ssize_t
set_bConfigurationValue(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device	*udev = to_usb_device(dev);
	int			config, value;

	if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
		return -EINVAL;
	usb_lock_device(udev);
	value = usb_set_configuration(udev, config);
	usb_unlock_device(udev);
	return (value < 0) ? value : count;
}

static DEVICE_ATTR(bConfigurationValue, S_IRUGO | S_IWUSR, 
		show_bConfigurationValue, set_bConfigurationValue);

/* String fields */
#define usb_string_attr(name)						\
static ssize_t  show_##name(struct device *dev,				\
		struct device_attribute *attr, char *buf)		\
{									\
	struct usb_device *udev;					\
									\
	udev = to_usb_device(dev);					\
	return sprintf(buf, "%s\n", udev->name);			\
}									\
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);

usb_string_attr(product);
usb_string_attr(manufacturer);
usb_string_attr(serial);

static ssize_t
show_speed(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	char *speed;

	udev = to_usb_device(dev);

	switch (udev->speed) {
	case USB_SPEED_LOW:
		speed = "1.5";
		break;
	case USB_SPEED_UNKNOWN:
	case USB_SPEED_FULL:
		speed = "12";
		break;
	case USB_SPEED_HIGH:
		speed = "480";
		break;
	default:
		speed = "unknown";
	}
	return sprintf(buf, "%s\n", speed);
}
static DEVICE_ATTR(speed, S_IRUGO, show_speed, NULL);

static ssize_t
show_busnum(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", udev->bus->busnum);
}
static DEVICE_ATTR(busnum, S_IRUGO, show_busnum, NULL);

static ssize_t
show_devnum(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", udev->devnum);
}
static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL);

static ssize_t
show_version(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	u16 bcdUSB;

	udev = to_usb_device(dev);
	bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
	return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);

static ssize_t
show_maxchild(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", udev->maxchild);
}
static DEVICE_ATTR(maxchild, S_IRUGO, show_maxchild, NULL);

static ssize_t
show_quirks(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "0x%x\n", udev->quirks);
}
static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);

static ssize_t
show_urbnum(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", atomic_read(&udev->urbnum));
}
static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);


#if defined(CONFIG_USB_PERSIST) || defined(CONFIG_USB_SUSPEND)
static const char power_group[] = "power";
#endif

#ifdef	CONFIG_USB_PERSIST

static ssize_t
show_persist(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev = to_usb_device(dev);

	return sprintf(buf, "%d\n", udev->persist_enabled);
}

static ssize_t
set_persist(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	int value;

	/* Hubs are always enabled for USB_PERSIST */
	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
		return -EPERM;

	if (sscanf(buf, "%d", &value) != 1)
		return -EINVAL;
	usb_pm_lock(udev);
	udev->persist_enabled = !!value;
	usb_pm_unlock(udev);
	return count;
}

static DEVICE_ATTR(persist, S_IRUGO | S_IWUSR, show_persist, set_persist);

static int add_persist_attributes(struct device *dev)
{
	int rc = 0;

	if (is_usb_device(dev)) {
		struct usb_device *udev = to_usb_device(dev);

		/* Hubs are automatically enabled for USB_PERSIST */
		if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
			udev->persist_enabled = 1;
		rc = sysfs_add_file_to_group(&dev->kobj,
				&dev_attr_persist.attr,
				power_group);
	}
	return rc;
}

static void remove_persist_attributes(struct device *dev)
{
	sysfs_remove_file_from_group(&dev->kobj,
			&dev_attr_persist.attr,
			power_group);
}

#else

#define add_persist_attributes(dev)	0
#define remove_persist_attributes(dev)	do {} while (0)

#endif	/* CONFIG_USB_PERSIST */

#ifdef	CONFIG_USB_SUSPEND

static ssize_t
show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev = to_usb_device(dev);

	return sprintf(buf, "%d\n", udev->autosuspend_delay / HZ);
}

static ssize_t
set_autosuspend(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	int value;

	if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/HZ ||
			value <= - INT_MAX/HZ)
		return -EINVAL;
	value *= HZ;

	udev->autosuspend_delay = value;
	if (value >= 0)
		usb_try_autosuspend_device(udev);
	else {
		if (usb_autoresume_device(udev) == 0)
			usb_autosuspend_device(udev);
	}
	return count;
}

static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
		show_autosuspend, set_autosuspend);

static const char on_string[] = "on";
static const char auto_string[] = "auto";
static const char suspend_string[] = "suspend";

static ssize_t
show_level(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev = to_usb_device(dev);
	const char *p = auto_string;

	if (udev->state == USB_STATE_SUSPENDED) {
		if (udev->autoresume_disabled)
			p = suspend_string;
	} else {
		if (udev->autosuspend_disabled)
			p = on_string;
	}
	return sprintf(buf, "%s\n", p);
}

static ssize_t
set_level(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	int len = count;
	char *cp;
	int rc = 0;
	int old_autosuspend_disabled, old_autoresume_disabled;

	cp = memchr(buf, '\n', count);
	if (cp)
		len = cp - buf;

	usb_lock_device(udev);
	old_autosuspend_disabled = udev->autosuspend_disabled;
	old_autoresume_disabled = udev->autoresume_disabled;

	/* Setting the flags without calling usb_pm_lock is a subject to
	 * races, but who cares...
	 */
	if (len == sizeof on_string - 1 &&
			strncmp(buf, on_string, len) == 0) {
		udev->autosuspend_disabled = 1;
		udev->autoresume_disabled = 0;
		rc = usb_external_resume_device(udev);

	} else if (len == sizeof auto_string - 1 &&
			strncmp(buf, auto_string, len) == 0) {
		udev->autosuspend_disabled = 0;
		udev->autoresume_disabled = 0;
		rc = usb_external_resume_device(udev);

	} else if (len == sizeof suspend_string - 1 &&
			strncmp(buf, suspend_string, len) == 0) {
		udev->autosuspend_disabled = 0;
		udev->autoresume_disabled = 1;
		rc = usb_external_suspend_device(udev, PMSG_SUSPEND);

	} else
		rc = -EINVAL;

	if (rc) {
		udev->autosuspend_disabled = old_autosuspend_disabled;
		udev->autoresume_disabled = old_autoresume_disabled;
	}
	usb_unlock_device(udev);
	return (rc < 0 ? rc : count);
}

static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);

static int add_power_attributes(struct device *dev)
{
	int rc = 0;

	if (is_usb_device(dev)) {
		rc = sysfs_add_file_to_group(&dev->kobj,
				&dev_attr_autosuspend.attr,
				power_group);
		if (rc == 0)
			rc = sysfs_add_file_to_group(&dev->kobj,
					&dev_attr_level.attr,
					power_group);
	}
	return rc;
}

static void remove_power_attributes(struct device *dev)
{
	sysfs_remove_file_from_group(&dev->kobj,
			&dev_attr_level.attr,
			power_group);
	sysfs_remove_file_from_group(&dev->kobj,
			&dev_attr_autosuspend.attr,
			power_group);
}

#else

#define add_power_attributes(dev)	0