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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/usb/core/devices.c
Initial import
Diffstat (limited to 'drivers/usb/core/devices.c')
-rw-r--r--drivers/usb/core/devices.c692
1 files changed, 692 insertions, 0 deletions
diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
new file mode 100644
index 000000000..2a3bbdf7e
--- /dev/null
+++ b/drivers/usb/core/devices.c
@@ -0,0 +1,692 @@
+/*
+ * devices.c
+ * (C) Copyright 1999 Randy Dunlap.
+ * (C) Copyright 1999,2000 Thomas Sailer <sailer@ife.ee.ethz.ch>.
+ * (proc file per device)
+ * (C) Copyright 1999 Deti Fliegl (new USB architecture)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *************************************************************
+ *
+ * <mountpoint>/devices contains USB topology, device, config, class,
+ * interface, & endpoint data.
+ *
+ * I considered using /proc/bus/usb/devices/device# for each device
+ * as it is attached or detached, but I didn't like this for some
+ * reason -- maybe it's just too deep of a directory structure.
+ * I also don't like looking in multiple places to gather and view
+ * the data. Having only one file for ./devices also prevents race
+ * conditions that could arise if a program was reading device info
+ * for devices that are being removed (unplugged). (That is, the
+ * program may find a directory for devnum_12 then try to open it,
+ * but it was just unplugged, so the directory is now deleted.
+ * But programs would just have to be prepared for situations like
+ * this in any plug-and-play environment.)
+ *
+ * 1999-12-16: Thomas Sailer <sailer@ife.ee.ethz.ch>
+ * Converted the whole proc stuff to real
+ * read methods. Now not the whole device list needs to fit
+ * into one page, only the device list for one bus.
+ * Added a poll method to /proc/bus/usb/devices, to wake
+ * up an eventual usbd
+ * 2000-01-04: Thomas Sailer <sailer@ife.ee.ethz.ch>
+ * Turned into its own filesystem
+ * 2000-07-05: Ashley Montanaro <ashley@compsoc.man.ac.uk>
+ * Converted file reading routine to dump to buffer once
+ * per device, not per bus
+ */
+
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/poll.h>
+#include <linux/usb.h>
+#include <linux/usbdevice_fs.h>
+#include <linux/usb/hcd.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+
+#include "usb.h"
+
+/* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */
+#define ALLOW_SERIAL_NUMBER
+
+static const char format_topo[] =
+/* T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd */
+"\nT: Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%-4s MxCh=%2d\n";
+
+static const char format_string_manufacturer[] =
+/* S: Manufacturer=xxxx */
+ "S: Manufacturer=%.100s\n";
+
+static const char format_string_product[] =
+/* S: Product=xxxx */
+ "S: Product=%.100s\n";
+
+#ifdef ALLOW_SERIAL_NUMBER
+static const char format_string_serialnumber[] =
+/* S: SerialNumber=xxxx */
+ "S: SerialNumber=%.100s\n";
+#endif
+
+static const char format_bandwidth[] =
+/* B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */
+ "B: Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n";
+
+static const char format_device1[] =
+/* D: Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */
+ "D: Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n";
+
+static const char format_device2[] =
+/* P: Vendor=xxxx ProdID=xxxx Rev=xx.xx */
+ "P: Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";
+
+static const char format_config[] =
+/* C: #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */
+ "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";
+
+static const char format_iad[] =
+/* A: FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */
+ "A: FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n";
+
+static const char format_iface[] =
+/* I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
+ "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
+
+static const char format_endpt[] =
+/* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
+ "E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
+
+
+/*
+ * Need access to the driver and USB bus lists.
+ * extern struct list_head usb_bus_list;
+ * However, these will come from functions that return ptrs to each of them.
+ */
+
+/*
+ * Wait for an connect/disconnect event to happen. We initialize
+ * the event counter with an odd number, and each event will increment
+ * the event counter by two, so it will always _stay_ odd. That means
+ * that it will never be zero, so "event 0" will never match a current
+ * event, and thus 'poll' will always trigger as readable for the first
+ * time it gets called.
+ */
+static struct device_connect_event {
+ atomic_t count;
+ wait_queue_head_t wait;
+} device_event = {
+ .count = ATOMIC_INIT(1),
+ .wait = __WAIT_QUEUE_HEAD_INITIALIZER(device_event.wait)
+};
+
+struct class_info {
+ int class;
+ char *class_name;
+};
+
+static const struct class_info clas_info[] = {
+ /* max. 5 chars. per name string */
+ {USB_CLASS_PER_INTERFACE, ">ifc"},
+ {USB_CLASS_AUDIO, "audio"},
+ {USB_CLASS_COMM, "comm."},
+ {USB_CLASS_HID, "HID"},
+ {USB_CLASS_PHYSICAL, "PID"},
+ {USB_CLASS_STILL_IMAGE, "still"},
+ {USB_CLASS_PRINTER, "print"},
+ {USB_CLASS_MASS_STORAGE, "stor."},
+ {USB_CLASS_HUB, "hub"},
+ {USB_CLASS_CDC_DATA, "data"},
+ {USB_CLASS_CSCID, "scard"},
+ {USB_CLASS_CONTENT_SEC, "c-sec"},
+ {USB_CLASS_VIDEO, "video"},
+ {USB_CLASS_WIRELESS_CONTROLLER, "wlcon"},
+ {USB_CLASS_MISC, "misc"},
+ {USB_CLASS_APP_SPEC, "app."},
+ {USB_CLASS_VENDOR_SPEC, "vend."},
+ {-1, "unk."} /* leave as last */
+};
+
+/*****************************************************************/
+
+void usbfs_conn_disc_event(void)
+{
+ atomic_add(2, &device_event.count);
+ wake_up(&device_event.wait);
+}
+
+static const char *class_decode(const int class)
+{
+ int ix;
+
+ for (ix = 0; clas_info[ix].class != -1; ix++)
+ if (clas_info[ix].class == class)
+ break;
+ return clas_info[ix].class_name;
+}
+
+static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end,
+ const struct usb_endpoint_descriptor *desc)
+{
+ char dir, unit, *type;
+ unsigned interval, bandwidth = 1;
+
+ if (start > end)
+ return start;
+
+ dir = usb_endpoint_dir_in(desc) ? 'I' : 'O';
+
+ if (speed == USB_SPEED_HIGH) {
+ switch (usb_endpoint_maxp(desc) & (0x03 << 11)) {
+ case 1 << 11:
+ bandwidth = 2; break;
+ case 2 << 11:
+ bandwidth = 3; break;
+ }
+ }
+
+ /* this isn't checking for illegal values */
+ switch (usb_endpoint_type(desc)) {
+ case USB_ENDPOINT_XFER_CONTROL:
+ type = "Ctrl";
+ if (speed == USB_SPEED_HIGH) /* uframes per NAK */
+ interval = desc->bInterval;
+ else
+ interval = 0;
+ dir = 'B'; /* ctrl is bidirectional */
+ break;
+ case USB_ENDPOINT_XFER_ISOC:
+ type = "Isoc";
+ interval = 1 << (desc->bInterval - 1);
+ break;
+ case USB_ENDPOINT_XFER_BULK:
+ type = "Bulk";
+ if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */
+ interval = desc->bInterval;
+ else
+ interval = 0;
+ break;
+ case USB_ENDPOINT_XFER_INT:
+ type = "Int.";
+ if (speed == USB_SPEED_HIGH || speed == USB_SPEED_SUPER)
+ interval = 1 << (desc->bInterval - 1);
+ else
+ interval = desc->bInterval;
+ break;
+ default: /* "can't happen" */
+ return start;
+ }
+ interval *= (speed == USB_SPEED_HIGH ||
+ speed == USB_SPEED_SUPER) ? 125 : 1000;
+ if (interval % 1000)
+ unit = 'u';
+ else {
+ unit = 'm';
+ interval /= 1000;
+ }
+
+ start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
+ desc->bmAttributes, type,
+ (usb_endpoint_maxp(desc) & 0x07ff) *
+ bandwidth,
+ interval, unit);
+ return start;
+}
+
+static char *usb_dump_interface_descriptor(char *start, char *end,
+ const struct usb_interface_cache *intfc,
+ const struct usb_interface *iface,
+ int setno)
+{
+ const struct usb_interface_descriptor *desc;
+ const char *driver_name = "";
+ int active = 0;
+
+ if (start > end)
+ return start;
+ desc = &intfc->altsetting[setno].desc;
+ if (iface) {
+ driver_name = (iface->dev.driver
+ ? iface->dev.driver->name
+ : "(none)");
+ active = (desc == &iface->cur_altsetting->desc);
+ }
+ start += sprintf(start, format_iface,
+ active ? '*' : ' ', /* mark active altsetting */
+ desc->bInterfaceNumber,
+ desc->bAlternateSetting,
+ desc->bNumEndpoints,
+ desc->bInterfaceClass,
+ class_decode(desc->bInterfaceClass),
+ desc->bInterfaceSubClass,
+ desc->bInterfaceProtocol,
+ driver_name);
+ return start;
+}
+
+static char *usb_dump_interface(int speed, char *start, char *end,
+ const struct usb_interface_cache *intfc,
+ const struct usb_interface *iface, int setno)
+{
+ const struct usb_host_interface *desc = &intfc->altsetting[setno];
+ int i;
+
+ start = usb_dump_interface_descriptor(start, end, intfc, iface, setno);
+ for (i = 0; i < desc->desc.bNumEndpoints; i++) {
+ if (start > end)
+ return start;
+ start = usb_dump_endpoint_descriptor(speed,
+ start, end, &desc->endpoint[i].desc);
+ }
+ return start;
+}
+
+static char *usb_dump_iad_descriptor(char *start, char *end,
+ const struct usb_interface_assoc_descriptor *iad)
+{
+ if (start > end)
+ return start;
+ start += sprintf(start, format_iad,
+ iad->bFirstInterface,
+ iad->bInterfaceCount,
+ iad->bFunctionClass,
+ class_decode(iad->bFunctionClass),
+ iad->bFunctionSubClass,
+ iad->bFunctionProtocol);
+ return start;
+}
+
+/* TBD:
+ * 0. TBDs
+ * 1. marking active interface altsettings (code lists all, but should mark
+ * which ones are active, if any)
+ */
+static char *usb_dump_config_descriptor(char *start, char *end,
+ const struct usb_config_descriptor *desc,
+ int active, int speed)
+{
+ int mul;
+
+ if (start > end)
+ return start;
+ if (speed == USB_SPEED_SUPER)
+ mul = 8;
+ else
+ mul = 2;
+ start += sprintf(start, format_config,
+ /* mark active/actual/current cfg. */
+ active ? '*' : ' ',
+ desc->bNumInterfaces,
+ desc->bConfigurationValue,
+ desc->bmAttributes,
+ desc->bMaxPower * mul);
+ return start;
+}
+
+static char *usb_dump_config(int speed, char *start, char *end,
+ const struct usb_host_config *config, int active)
+{
+ int i, j;
+ struct usb_interface_cache *intfc;
+ struct usb_interface *interface;
+
+ if (start > end)
+ return start;
+ if (!config)
+ /* getting these some in 2.3.7; none in 2.3.6 */
+ return start + sprintf(start, "(null Cfg. desc.)\n");
+ start = usb_dump_config_descriptor(start, end, &config->desc, active,
+ speed);
+ for (i = 0; i < USB_MAXIADS; i++) {
+ if (config->intf_assoc[i] == NULL)
+ break;
+ start = usb_dump_iad_descriptor(start, end,
+ config->intf_assoc[i]);
+ }
+ for (i = 0; i < config->desc.bNumInterfaces; i++) {
+ intfc = config->intf_cache[i];
+ interface = config->interface[i];
+ for (j = 0; j < intfc->num_altsetting; j++) {
+ if (start > end)
+ return start;
+ start = usb_dump_interface(speed,
+ start, end, intfc, interface, j);
+ }
+ }
+ return start;
+}
+
+/*
+ * Dump the different USB descriptors.
+ */
+static char *usb_dump_device_descriptor(char *start, char *end,
+ const struct usb_device_descriptor *desc)
+{
+ u16 bcdUSB = le16_to_cpu(desc->bcdUSB);
+ u16 bcdDevice = le16_to_cpu(desc->bcdDevice);
+
+ if (start > end)
+ return start;
+ start += sprintf(start, format_device1,
+ bcdUSB >> 8, bcdUSB & 0xff,
+ desc->bDeviceClass,
+ class_decode(desc->bDeviceClass),
+ desc->bDeviceSubClass,
+ desc->bDeviceProtocol,
+ desc->bMaxPacketSize0,
+ desc->bNumConfigurations);
+ if (start > end)
+ return start;
+ start += sprintf(start, format_device2,
+ le16_to_cpu(desc->idVendor),
+ le16_to_cpu(desc->idProduct),
+ bcdDevice >> 8, bcdDevice & 0xff);
+ return start;
+}
+
+/*
+ * Dump the different strings that this device holds.
+ */
+static char *usb_dump_device_strings(char *start, char *end,
+ struct usb_device *dev)
+{
+ if (start > end)
+ return start;
+ if (dev->manufacturer)
+ start += sprintf(start, format_string_manufacturer,
+ dev->manufacturer);
+ if (start > end)
+ goto out;
+ if (dev->product)
+ start += sprintf(start, format_string_product, dev->product);
+ if (start > end)
+ goto out;
+#ifdef ALLOW_SERIAL_NUMBER
+ if (dev->serial)
+ start += sprintf(start, format_string_serialnumber,
+ dev->serial);
+#endif
+ out:
+ return start;
+}
+
+static char *usb_dump_desc(char *start, char *end, struct usb_device *dev)
+{
+ int i;
+
+ if (start > end)
+ return start;
+
+ start = usb_dump_device_descriptor(start, end, &dev->descriptor);
+
+ if (start > end)
+ return start;
+
+ start = usb_dump_device_strings(start, end, dev);
+
+ for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
+ if (start > end)
+ return start;
+ start = usb_dump_config(dev->speed,
+ start, end, dev->config + i,
+ /* active ? */
+ (dev->config + i) == dev->actconfig);
+ }
+ return start;
+}
+
+
+#ifdef PROC_EXTRA /* TBD: may want to add this code later */
+
+static char *usb_dump_hub_descriptor(char *start, char *end,
+ const struct usb_hub_descriptor *desc)
+{
+ int leng = USB_DT_HUB_NONVAR_SIZE;
+ unsigned char *ptr = (unsigned char *)desc;
+
+ if (start > end)
+ return start;
+ start += sprintf(start, "Interface:");
+ while (leng && start <= end) {
+ start += sprintf(start, " %02x", *ptr);
+ ptr++; leng--;
+ }
+ *start++ = '\n';
+ return start;
+}
+
+static char *usb_dump_string(char *start, char *end,
+ const struct usb_device *dev, char *id, int index)
+{
+ if (start > end)
+ return start;
+ start += sprintf(start, "Interface:");
+ if (index <= dev->maxstring && dev->stringindex &&
+ dev->stringindex[index])
+ start += sprintf(start, "%s: %.100s ", id,
+ dev->stringindex[index]);
+ return start;
+}
+
+#endif /* PROC_EXTRA */
+
+/*****************************************************************/
+
+/* This is a recursive function. Parameters:
+ * buffer - the user-space buffer to write data into
+ * nbytes - the maximum number of bytes to write
+ * skip_bytes - the number of bytes to skip before writing anything
+ * file_offset - the offset into the devices file on completion
+ * The caller must own the device lock.
+ */
+static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
+ loff_t *skip_bytes, loff_t *file_offset,
+ struct usb_device *usbdev, struct usb_bus *bus,
+ int level, int index, int count)
+{
+ int chix;
+ int ret, cnt = 0;
+ int parent_devnum = 0;
+ char *pages_start, *data_end, *speed;
+ unsigned int length;
+ ssize_t total_written = 0;
+ struct usb_device *childdev = NULL;
+
+ /* don't bother with anything else if we're not writing any data */
+ if (*nbytes <= 0)
+ return 0;
+
+ if (level > MAX_TOPO_LEVEL)
+ return 0;
+ /* allocate 2^1 pages = 8K (on i386);
+ * should be more than enough for one device */
+ pages_start = (char *)__get_free_pages(GFP_NOIO, 1);
+ if (!pages_start)
+ return -ENOMEM;
+
+ if (usbdev->parent && usbdev->parent->devnum != -1)
+ parent_devnum = usbdev->parent->devnum;
+ /*
+ * So the root hub's parent is 0 and any device that is
+ * plugged into the root hub has a parent of 0.
+ */
+ switch (usbdev->speed) {
+ case USB_SPEED_LOW:
+ speed = "1.5"; break;
+ case USB_SPEED_UNKNOWN: /* usb 1.1 root hub code */
+ case USB_SPEED_FULL:
+ speed = "12"; break;
+ case USB_SPEED_WIRELESS: /* Wireless has no real fixed speed */
+ case USB_SPEED_HIGH:
+ speed = "480"; break;
+ case USB_SPEED_SUPER:
+ speed = "5000"; break;
+ default:
+ speed = "??";
+ }
+ data_end = pages_start + sprintf(pages_start, format_topo,
+ bus->busnum, level, parent_devnum,
+ index, count, usbdev->devnum,
+ speed, usbdev->maxchild);
+ /*
+ * level = topology-tier level;
+ * parent_devnum = parent device number;
+ * index = parent's connector number;
+ * count = device count at this level
+ */
+ /* If this is the root hub, display the bandwidth information */
+ if (level == 0) {
+ int max;
+
+ /* super/high speed reserves 80%, full/low reserves 90% */
+ if (usbdev->speed == USB_SPEED_HIGH ||
+ usbdev->speed == USB_SPEED_SUPER)
+ max = 800;
+ else
+ max = FRAME_TIME_MAX_USECS_ALLOC;
+
+ /* report "average" periodic allocation over a microsecond.
+ * the schedules are actually bursty, HCDs need to deal with
+ * that and just compute/report this average.
+ */
+ data_end += sprintf(data_end, format_bandwidth,
+ bus->bandwidth_allocated, max,
+ (100 * bus->bandwidth_allocated + max / 2)
+ / max,
+ bus->bandwidth_int_reqs,
+ bus->bandwidth_isoc_reqs);
+
+ }
+ data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256,
+ usbdev);
+
+ if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
+ data_end += sprintf(data_end, "(truncated)\n");
+
+ length = data_end - pages_start;
+ /* if we can start copying some data to the user */
+ if (length > *skip_bytes) {
+ length -= *skip_bytes;
+ if (length > *nbytes)
+ length = *nbytes;
+ if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) {
+ free_pages((unsigned long)pages_start, 1);
+ return -EFAULT;
+ }
+ *nbytes -= length;
+ *file_offset += length;
+ total_written += length;
+ *buffer += length;
+ *skip_bytes = 0;
+ } else
+ *skip_bytes -= length;
+
+ free_pages((unsigned long)pages_start, 1);
+
+ /* Now look at all of this device's children. */
+ usb_hub_for_each_child(usbdev, chix, childdev) {
+ usb_lock_device(childdev);
+ ret = usb_device_dump(buffer, nbytes, skip_bytes,
+ file_offset, childdev, bus,
+ level + 1, chix - 1, ++cnt);
+ usb_unlock_device(childdev);
+ if (ret == -EFAULT)
+ return total_written;
+ total_written += ret;
+ }
+ return total_written;
+}
+
+static ssize_t usb_device_read(struct file *file, char __user *buf,
+ size_t nbytes, loff_t *ppos)
+{
+ struct usb_bus *bus;
+ ssize_t ret, total_written = 0;
+ loff_t skip_bytes = *ppos;
+
+ if (*ppos < 0)
+ return -EINVAL;
+ if (nbytes <= 0)
+ return 0;
+ if (!access_ok(VERIFY_WRITE, buf, nbytes))
+ return -EFAULT;
+
+ mutex_lock(&usb_bus_list_lock);
+ /* print devices for all busses */
+ list_for_each_entry(bus, &usb_bus_list, bus_list) {
+ /* recurse through all children of the root hub */
+ if (!bus_to_hcd(bus)->rh_registered)
+ continue;
+ usb_lock_device(bus->root_hub);
+ ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos,
+ bus->root_hub, bus, 0, 0, 0);
+ usb_unlock_device(bus->root_hub);
+ if (ret < 0) {
+ mutex_unlock(&usb_bus_list_lock);
+ return ret;
+ }
+ total_written += ret;
+ }
+ mutex_unlock(&usb_bus_list_lock);
+ return total_written;
+}
+
+/* Kernel lock for "lastev" protection */
+static unsigned int usb_device_poll(struct file *file,
+ struct poll_table_struct *wait)
+{
+ unsigned int event_count;
+
+ poll_wait(file, &device_event.wait, wait);
+
+ event_count = atomic_read(&device_event.count);
+ if (file->f_version != event_count) {
+ file->f_version = event_count;
+ return POLLIN | POLLRDNORM;
+ }
+
+ return 0;
+}
+
+static loff_t usb_device_lseek(struct file *file, loff_t offset, int orig)
+{
+ loff_t ret;
+
+ mutex_lock(&file_inode(file)->i_mutex);
+
+ switch (orig) {
+ case 0:
+ file->f_pos = offset;
+ ret = file->f_pos;
+ break;
+ case 1:
+ file->f_pos += offset;
+ ret = file->f_pos;
+ break;
+ case 2:
+ default:
+ ret = -EINVAL;
+ }
+
+ mutex_unlock(&file_inode(file)->i_mutex);
+ return ret;
+}
+
+const struct file_operations usbfs_devices_fops = {
+ .llseek = usb_device_lseek,
+ .read = usb_device_read,
+ .poll = usb_device_poll,
+};