linux/drivers/usb/core/sysfs.c
Alan Stern 356c05d58a sysfs: get rid of some lockdep false positives
This patch (as1554) fixes a lockdep false-positive report.  The
problem arises because lockdep is unable to deal with the
tree-structured locks created by the device core and sysfs.

This particular problem involves a sysfs attribute method that
unregisters itself, not from the device it was called for, but from a
descendant device.  Lockdep doesn't understand the distinction and
reports a possible deadlock, even though the operation is safe.

This is the sort of thing that would normally be handled by using a
nested lock annotation; unfortunately it's not feasible to do that
here.  There's no sensible way to tell sysfs when attribute removal
occurs in the context of a parent attribute method.

As a workaround, the patch adds a new flag to struct attribute
telling sysfs not to inform lockdep when it acquires a readlock on a
sysfs_dirent instance for the attribute.  The readlock is still
acquired, but lockdep doesn't know about it and hence does not
complain about impossible deadlock scenarios.

Also added are macros for static initialization of attribute
structures with the ignore_lockdep flag set.  The three offending
attributes in the USB subsystem are converted to use the new macros.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Tejun Heo <tj@kernel.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-14 12:19:56 -07:00

947 lines
24 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_IGNORE_LOCKDEP(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; \
int retval; \
\
udev = to_usb_device(dev); \
usb_lock_device(udev); \
retval = sprintf(buf, "%s\n", udev->name); \
usb_unlock_device(udev); \
return retval; \
} \
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;
case USB_SPEED_WIRELESS:
speed = "480";
break;
case USB_SPEED_SUPER:
speed = "5000";
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_devpath(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%s\n", udev->devpath);
}
static DEVICE_ATTR(devpath, S_IRUGO, show_devpath, 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_avoid_reset_quirk(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", !!(udev->quirks & USB_QUIRK_RESET_MORPHS));
}
static ssize_t
set_avoid_reset_quirk(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int config;
if (sscanf(buf, "%d", &config) != 1 || config < 0 || config > 1)
return -EINVAL;
usb_lock_device(udev);
if (config)
udev->quirks |= USB_QUIRK_RESET_MORPHS;
else
udev->quirks &= ~USB_QUIRK_RESET_MORPHS;
usb_unlock_device(udev);
return count;
}
static DEVICE_ATTR(avoid_reset_quirk, S_IRUGO | S_IWUSR,
show_avoid_reset_quirk, set_avoid_reset_quirk);
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);
static ssize_t
show_removable(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
char *state;
udev = to_usb_device(dev);
switch (udev->removable) {
case USB_DEVICE_REMOVABLE:
state = "removable";
break;
case USB_DEVICE_FIXED:
state = "fixed";
break;
default:
state = "unknown";
}
return sprintf(buf, "%s\n", state);
}
static DEVICE_ATTR(removable, S_IRUGO, show_removable, NULL);
#ifdef CONFIG_PM
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_lock_device(udev);
udev->persist_enabled = !!value;
usb_unlock_device(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_name);
}
return rc;
}
static void remove_persist_attributes(struct device *dev)
{
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_persist.attr,
power_group_name);
}
#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)
{
return sprintf(buf, "%d\n", dev->power.autosuspend_delay / 1000);
}
static ssize_t
set_autosuspend(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
int value;
if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/1000 ||
value <= -INT_MAX/1000)
return -EINVAL;
pm_runtime_set_autosuspend_delay(dev, value * 1000);
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 void warn_level(void) {
static int level_warned;
if (!level_warned) {
level_warned = 1;
printk(KERN_WARNING "WARNING! power/level is deprecated; "
"use power/control instead\n");
}
}
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;
warn_level();
if (udev->state != USB_STATE_SUSPENDED && !udev->dev.power.runtime_auto)
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 = count;
warn_level();
cp = memchr(buf, '\n', count);
if (cp)
len = cp - buf;
usb_lock_device(udev);
if (len == sizeof on_string - 1 &&
strncmp(buf, on_string, len) == 0)
usb_disable_autosuspend(udev);
else if (len == sizeof auto_string - 1 &&
strncmp(buf, auto_string, len) == 0)
usb_enable_autosuspend(udev);
else
rc = -EINVAL;
usb_unlock_device(udev);
return rc;
}
static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);
static ssize_t
show_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct usb_device *udev = to_usb_device(dev);
const char *p;
if (udev->usb2_hw_lpm_enabled == 1)
p = "enabled";
else
p = "disabled";
return sprintf(buf, "%s\n", p);
}
static ssize_t
set_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
bool value;
int ret;
usb_lock_device(udev);
ret = strtobool(buf, &value);
if (!ret)
ret = usb_set_usb2_hardware_lpm(udev, value);
usb_unlock_device(udev);
if (!ret)
return count;
return ret;
}
static DEVICE_ATTR(usb2_hardware_lpm, S_IRUGO | S_IWUSR, show_usb2_hardware_lpm,
set_usb2_hardware_lpm);
static struct attribute *usb2_hardware_lpm_attr[] = {
&dev_attr_usb2_hardware_lpm.attr,
NULL,
};
static struct attribute_group usb2_hardware_lpm_attr_group = {
.name = power_group_name,
.attrs = usb2_hardware_lpm_attr,
};
static struct attribute *power_attrs[] = {
&dev_attr_autosuspend.attr,
&dev_attr_level.attr,
&dev_attr_connected_duration.attr,
&dev_attr_active_duration.attr,
NULL,
};
static struct attribute_group power_attr_group = {
.name = power_group_name,
.attrs = power_attrs,
};
static int add_power_attributes(struct device *dev)
{
int rc = 0;
if (is_usb_device(dev)) {
struct usb_device *udev = to_usb_device(dev);
rc = sysfs_merge_group(&dev->kobj, &power_attr_group);
if (udev->usb2_hw_lpm_capable == 1)
rc = sysfs_merge_group(&dev->kobj,
&usb2_hardware_lpm_attr_group);
}
return rc;
}
static void remove_power_attributes(struct device *dev)
{
sysfs_unmerge_group(&dev->kobj, &usb2_hardware_lpm_attr_group);
sysfs_unmerge_group(&dev->kobj, &power_attr_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_IGNORE_LOCKDEP(authorized, 0644,
usb_dev_authorized_show, usb_dev_authorized_store);
/* "Safely remove a device" */
static ssize_t usb_remove_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int rc = 0;
usb_lock_device(udev);
if (udev->state != USB_STATE_NOTATTACHED) {
/* To avoid races, first unconfigure and then remove */
usb_set_configuration(udev, -1);
rc = usb_remove_device(udev);
}
if (rc == 0)
rc = count;
usb_unlock_device(udev);
return rc;
}
static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0200, NULL, usb_remove_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,
/* device attributes */
&dev_attr_urbnum.attr,
&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_devpath.attr,
&dev_attr_version.attr,
&dev_attr_maxchild.attr,
&dev_attr_quirks.attr,
&dev_attr_avoid_reset_quirk.attr,
&dev_attr_authorized.attr,
&dev_attr_remove.attr,
&dev_attr_removable.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 umode_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,
};
const struct attribute_group *usb_device_groups[] = {
&dev_attr_grp,
&dev_string_attr_grp,
NULL
};
/* Binary descriptors */
static ssize_t
read_descriptors(struct file *filp, 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 umode_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,
};
const struct attribute_group *usb_interface_groups[] = {
&intf_attr_grp,
&intf_assoc_attr_grp,
NULL
};
void 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;
if (intf->sysfs_files_created || intf->unregistering)
return;
if (!alt->string && !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
alt->string = usb_cache_string(udev, alt->desc.iInterface);
if (alt->string && device_create_file(&intf->dev, &dev_attr_interface))
; /* We don't actually care if the function fails. */
intf->sysfs_files_created = 1;
}
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;
}