linux/drivers/usb/core/sysfs.c

834 lines
21 KiB
C

/*
* 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 <linux/usb/quirks.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);
#ifdef CONFIG_PM
static const char power_group[] = "power";
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,
* no point in creating the attribute file.
*/
if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
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_PM */
#ifdef CONFIG_USB_SUSPEND
static ssize_t
show_connected_duration(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%u\n",
jiffies_to_msecs(jiffies - udev->connect_time));
}
static DEVICE_ATTR(connected_duration, S_IRUGO, show_connected_duration, NULL);
/*
* If the device is resumed, the last time the device was suspended has
* been pre-subtracted from active_duration. We add the current time to
* get the duration that the device was actually active.
*
* If the device is suspended, the active_duration is up-to-date.
*/
static ssize_t
show_active_duration(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev = to_usb_device(dev);
int duration;
if (udev->state != USB_STATE_SUSPENDED)
duration = jiffies_to_msecs(jiffies + udev->active_duration);
else
duration = jiffies_to_msecs(udev->active_duration);
return sprintf(buf, "%u\n", duration);
}
static DEVICE_ATTR(active_duration, S_IRUGO, show_active_duration, NULL);
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, PMSG_USER_RESUME);
} 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, PMSG_USER_RESUME);
} 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_USER_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);
if (rc == 0)
rc = sysfs_add_file_to_group(&dev->kobj,
&dev_attr_connected_duration.attr,
power_group);
if (rc == 0)
rc = sysfs_add_file_to_group(&dev->kobj,
&dev_attr_active_duration.attr,
power_group);
}
return rc;
}
static void remove_power_attributes(struct device *dev)
{
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_active_duration.attr,
power_group);
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_connected_duration.attr,
power_group);
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
#define remove_power_attributes(dev) do {} while (0)
#endif /* CONFIG_USB_SUSPEND */
/* Descriptor fields */
#define usb_descriptor_attr_le16(field, format_string) \
static ssize_t \
show_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, format_string, \
le16_to_cpu(udev->descriptor.field)); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_descriptor_attr_le16(idVendor, "%04x\n")
usb_descriptor_attr_le16(idProduct, "%04x\n")
usb_descriptor_attr_le16(bcdDevice, "%04x\n")
#define usb_descriptor_attr(field, format_string) \
static ssize_t \
show_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, format_string, udev->descriptor.field); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_descriptor_attr(bDeviceClass, "%02x\n")
usb_descriptor_attr(bDeviceSubClass, "%02x\n")
usb_descriptor_attr(bDeviceProtocol, "%02x\n")
usb_descriptor_attr(bNumConfigurations, "%d\n")
usb_descriptor_attr(bMaxPacketSize0, "%d\n")
/* show if the device is authorized (1) or not (0) */
static ssize_t usb_dev_authorized_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct usb_device *usb_dev = to_usb_device(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
}
/*
* Authorize a device to be used in the system
*
* Writing a 0 deauthorizes the device, writing a 1 authorizes it.
*/
static ssize_t usb_dev_authorized_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
ssize_t result;
struct usb_device *usb_dev = to_usb_device(dev);
unsigned val;
result = sscanf(buf, "%u\n", &val);
if (result != 1)
result = -EINVAL;
else if (val == 0)
result = usb_deauthorize_device(usb_dev);
else
result = usb_authorize_device(usb_dev);
return result < 0? result : size;
}
static DEVICE_ATTR(authorized, 0644,
usb_dev_authorized_show, usb_dev_authorized_store);
static struct attribute *dev_attrs[] = {
/* current configuration's attributes */
&dev_attr_configuration.attr,
&dev_attr_bNumInterfaces.attr,
&dev_attr_bConfigurationValue.attr,
&dev_attr_bmAttributes.attr,
&dev_attr_bMaxPower.attr,
&dev_attr_urbnum.attr,
/* device attributes */
&dev_attr_idVendor.attr,
&dev_attr_idProduct.attr,
&dev_attr_bcdDevice.attr,
&dev_attr_bDeviceClass.attr,
&dev_attr_bDeviceSubClass.attr,
&dev_attr_bDeviceProtocol.attr,
&dev_attr_bNumConfigurations.attr,
&dev_attr_bMaxPacketSize0.attr,
&dev_attr_speed.attr,
&dev_attr_busnum.attr,
&dev_attr_devnum.attr,
&dev_attr_version.attr,
&dev_attr_maxchild.attr,
&dev_attr_quirks.attr,
&dev_attr_authorized.attr,
NULL,
};
static struct attribute_group dev_attr_grp = {
.attrs = dev_attrs,
};
/* When modifying this list, be sure to modify dev_string_attrs_are_visible()
* accordingly.
*/
static struct attribute *dev_string_attrs[] = {
&dev_attr_manufacturer.attr,
&dev_attr_product.attr,
&dev_attr_serial.attr,
NULL
};
static mode_t dev_string_attrs_are_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct usb_device *udev = to_usb_device(dev);
if (a == &dev_attr_manufacturer.attr) {
if (udev->manufacturer == NULL)
return 0;
} else if (a == &dev_attr_product.attr) {
if (udev->product == NULL)
return 0;
} else if (a == &dev_attr_serial.attr) {
if (udev->serial == NULL)
return 0;
}
return a->mode;
}
static struct attribute_group dev_string_attr_grp = {
.attrs = dev_string_attrs,
.is_visible = dev_string_attrs_are_visible,
};
struct attribute_group *usb_device_groups[] = {
&dev_attr_grp,
&dev_string_attr_grp,
NULL
};
/* Binary descriptors */
static ssize_t
read_descriptors(struct kobject *kobj, struct bin_attribute *attr,
char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct usb_device *udev = to_usb_device(dev);
size_t nleft = count;
size_t srclen, n;
int cfgno;
void *src;
/* The binary attribute begins with the device descriptor.
* Following that are the raw descriptor entries for all the
* configurations (config plus subsidiary descriptors).
*/
for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
nleft > 0; ++cfgno) {
if (cfgno < 0) {
src = &udev->descriptor;
srclen = sizeof(struct usb_device_descriptor);
} else {
src = udev->rawdescriptors[cfgno];
srclen = __le16_to_cpu(udev->config[cfgno].desc.
wTotalLength);
}
if (off < srclen) {
n = min(nleft, srclen - (size_t) off);
memcpy(buf, src + off, n);
nleft -= n;
buf += n;
off = 0;
} else {
off -= srclen;
}
}
return count - nleft;
}
static struct bin_attribute dev_bin_attr_descriptors = {
.attr = {.name = "descriptors", .mode = 0444},
.read = read_descriptors,
.size = 18 + 65535, /* dev descr + max-size raw descriptor */
};
int usb_create_sysfs_dev_files(struct usb_device *udev)
{
struct device *dev = &udev->dev;
int retval;
retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
if (retval)
goto error;
retval = add_persist_attributes(dev);
if (retval)
goto error;
retval = add_power_attributes(dev);
if (retval)
goto error;
return retval;
error:
usb_remove_sysfs_dev_files(udev);
return retval;
}
void usb_remove_sysfs_dev_files(struct usb_device *udev)
{
struct device *dev = &udev->dev;
remove_power_attributes(dev);
remove_persist_attributes(dev);
device_remove_bin_file(dev, &dev_bin_attr_descriptors);
}
/* Interface Accociation Descriptor fields */
#define usb_intf_assoc_attr(field, format_string) \
static ssize_t \
show_iad_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
\
return sprintf(buf, format_string, \
intf->intf_assoc->field); \
} \
static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);
usb_intf_assoc_attr(bFirstInterface, "%02x\n")
usb_intf_assoc_attr(bInterfaceCount, "%02d\n")
usb_intf_assoc_attr(bFunctionClass, "%02x\n")
usb_intf_assoc_attr(bFunctionSubClass, "%02x\n")
usb_intf_assoc_attr(bFunctionProtocol, "%02x\n")
/* Interface fields */
#define usb_intf_attr(field, format_string) \
static ssize_t \
show_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
\
return sprintf(buf, format_string, \
intf->cur_altsetting->desc.field); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_intf_attr(bInterfaceNumber, "%02x\n")
usb_intf_attr(bAlternateSetting, "%2d\n")
usb_intf_attr(bNumEndpoints, "%02x\n")
usb_intf_attr(bInterfaceClass, "%02x\n")
usb_intf_attr(bInterfaceSubClass, "%02x\n")
usb_intf_attr(bInterfaceProtocol, "%02x\n")
static ssize_t show_interface_string(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf;
char *string;
intf = to_usb_interface(dev);
string = intf->cur_altsetting->string;
barrier(); /* The altsetting might change! */
if (!string)
return 0;
return sprintf(buf, "%s\n", string);
}
static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);
static ssize_t show_modalias(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf;
struct usb_device *udev;
struct usb_host_interface *alt;
intf = to_usb_interface(dev);
udev = interface_to_usbdev(intf);
alt = intf->cur_altsetting;
return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
"ic%02Xisc%02Xip%02X\n",
le16_to_cpu(udev->descriptor.idVendor),
le16_to_cpu(udev->descriptor.idProduct),
le16_to_cpu(udev->descriptor.bcdDevice),
udev->descriptor.bDeviceClass,
udev->descriptor.bDeviceSubClass,
udev->descriptor.bDeviceProtocol,
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol);
}
static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
static ssize_t show_supports_autosuspend(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf;
struct usb_device *udev;
int ret;
intf = to_usb_interface(dev);
udev = interface_to_usbdev(intf);
usb_lock_device(udev);
/* Devices will be autosuspended even when an interface isn't claimed */
if (!intf->dev.driver ||
to_usb_driver(intf->dev.driver)->supports_autosuspend)
ret = sprintf(buf, "%u\n", 1);
else
ret = sprintf(buf, "%u\n", 0);
usb_unlock_device(udev);
return ret;
}
static DEVICE_ATTR(supports_autosuspend, S_IRUGO, show_supports_autosuspend, NULL);
static struct attribute *intf_attrs[] = {
&dev_attr_bInterfaceNumber.attr,
&dev_attr_bAlternateSetting.attr,
&dev_attr_bNumEndpoints.attr,
&dev_attr_bInterfaceClass.attr,
&dev_attr_bInterfaceSubClass.attr,
&dev_attr_bInterfaceProtocol.attr,
&dev_attr_modalias.attr,
&dev_attr_supports_autosuspend.attr,
NULL,
};
static struct attribute_group intf_attr_grp = {
.attrs = intf_attrs,
};
static struct attribute *intf_assoc_attrs[] = {
&dev_attr_iad_bFirstInterface.attr,
&dev_attr_iad_bInterfaceCount.attr,
&dev_attr_iad_bFunctionClass.attr,
&dev_attr_iad_bFunctionSubClass.attr,
&dev_attr_iad_bFunctionProtocol.attr,
NULL,
};
static mode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
struct attribute *a, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct usb_interface *intf = to_usb_interface(dev);
if (intf->intf_assoc == NULL)
return 0;
return a->mode;
}
static struct attribute_group intf_assoc_attr_grp = {
.attrs = intf_assoc_attrs,
.is_visible = intf_assoc_attrs_are_visible,
};
struct attribute_group *usb_interface_groups[] = {
&intf_attr_grp,
&intf_assoc_attr_grp,
NULL
};
int usb_create_sysfs_intf_files(struct usb_interface *intf)
{
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *alt = intf->cur_altsetting;
int retval;
if (intf->sysfs_files_created || intf->unregistering)
return 0;
if (alt->string == NULL &&
!(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
alt->string = usb_cache_string(udev, alt->desc.iInterface);
if (alt->string)
retval = device_create_file(&intf->dev, &dev_attr_interface);
intf->sysfs_files_created = 1;
return 0;
}
void usb_remove_sysfs_intf_files(struct usb_interface *intf)
{
if (!intf->sysfs_files_created)
return;
device_remove_file(&intf->dev, &dev_attr_interface);
intf->sysfs_files_created = 0;
}