aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/core
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/sysfs.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index d47ae89154a..2ab222be8fd 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -441,6 +441,54 @@ static struct attribute_group dev_attr_grp = {
.attrs = dev_attrs,
};
+/* Binary descriptors */
+
+static ssize_t
+read_descriptors(struct kobject *kobj, struct bin_attribute *attr,
+ char *buf, loff_t off, size_t count)
+{
+ struct usb_device *udev = to_usb_device(
+ container_of(kobj, struct device, kobj));
+ size_t nleft = count;
+ size_t srclen, n;
+
+ usb_lock_device(udev);
+
+ /* The binary attribute begins with the device descriptor */
+ srclen = sizeof(struct usb_device_descriptor);
+ if (off < srclen) {
+ n = min_t(size_t, nleft, srclen - off);
+ memcpy(buf, off + (char *) &udev->descriptor, n);
+ nleft -= n;
+ buf += n;
+ off = 0;
+ } else {
+ off -= srclen;
+ }
+
+ /* Then follows the raw descriptor entry for the current
+ * configuration (config plus subsidiary descriptors).
+ */
+ if (udev->actconfig) {
+ int cfgno = udev->actconfig - udev->config;
+
+ srclen = __le16_to_cpu(udev->actconfig->desc.wTotalLength);
+ if (off < srclen) {
+ n = min_t(size_t, nleft, srclen - off);
+ memcpy(buf, off + udev->rawdescriptors[cfgno], n);
+ nleft -= n;
+ }
+ }
+ usb_unlock_device(udev);
+ 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;
@@ -450,6 +498,10 @@ int usb_create_sysfs_dev_files(struct usb_device *udev)
if (retval)
return retval;
+ retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
+ if (retval)
+ goto error;
+
retval = add_persist_attributes(dev);
if (retval)
goto error;
@@ -492,6 +544,7 @@ void usb_remove_sysfs_dev_files(struct usb_device *udev)
device_remove_file(dev, &dev_attr_serial);
remove_power_attributes(dev);
remove_persist_attributes(dev);
+ device_remove_bin_file(dev, &dev_bin_attr_descriptors);
sysfs_remove_group(&dev->kobj, &dev_attr_grp);
}