// SPDX-License-Identifier: GPL-2.0+
/*
* devices.c
* (C) Copyright 1999 Randy Dunlap.
* (C) Copyright 1999,2000 Thomas Sailer <[email protected]>.
* (proc file per device)
* (C) Copyright 1999 Deti Fliegl (new USB architecture)
*
*************************************************************
*
* <mountpoint>/devices contains USB topology, device, config, class,
* interface, & endpoint data.
*
* I considered using /dev/bus/usb/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 <[email protected]>
* 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 /sys/kernel/debug/usb/devices, to wake
* up an eventual usbd
* 2000-01-04: Thomas Sailer <[email protected]>
* Turned into its own filesystem
* 2000-07-05: Ashley Montanaro <[email protected]>
* 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/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";
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_PERSONAL_HEALTHCARE, "perhc"},
{USB_CLASS_AUDIO_VIDEO, "av"},
{USB_CLASS_BILLBOARD, "blbrd"},
{USB_CLASS_USB_TYPE_C_BRIDGE, "bridg"},
{USB_CLASS_WIRELESS_CONTROLLER, "wlcon"},
{USB_CLASS_MISC, "misc"},
{USB_CLASS_APP_SPEC, "app."},
{USB_CLASS_VENDOR_SPEC, "vend."},
{-1, "unk."} /* leave as last */
};
/*****************************************************************/
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)
bandwidth = usb_endpoint_maxp_mult(desc);
/* this isn't checking for illegal values */
switch (usb_endpoint_type(desc)) {
case USB_ENDPOINT_XFER_CONTROL:
type = "Ctrl";
dir = 'B'; /* ctrl is bidirectional */
break;
case USB_ENDPOINT_XFER_ISOC:
type = "Isoc";
break;
case USB_ENDPOINT_XFER_BULK:
type = "Bulk";
break;
case USB_ENDPOINT_XFER_INT:
type = "Int.";
break;
default: /* "can't happen" */
return start;
}
interval = usb_decode_interval(desc, speed);
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) *
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++) {
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++) {
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;
start = usb_dump_device_descriptor(start, end, &dev->descriptor);
start = usb_dump_device_strings(start, end, dev);
for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
start = usb_dump_config(dev->speed,
start, end, dev->config + i,
/* active ? */
(dev->config + i) == dev->actconfig);
}
return start;
}
/*****************************************************************/
/* 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_HIGH:
speed = "480"; break;
case USB_SPEED_SUPER:
speed = "5000"; break;
case USB_SPEED_SUPER_PLUS:
speed = "10000"; 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;
int id;
if (*ppos < 0)
return -EINVAL;
if (nbytes <= 0)
return 0;
mutex_lock(&usb_bus_idr_lock);
/* print devices for all busses */
idr_for_each_entry(&usb_bus_idr, bus, id) {
/* 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_idr_lock);
return ret;
}
total_written += ret;
}
mutex_unlock(&usb_bus_idr_lock);
return total_written;
}
const struct file_operations usbfs_devices_fops = {
.llseek = no_seek_end_llseek,
.read = usb_device_read,
};
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