path: root/drivers/usb/core/devices.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * 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 /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 <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 /sys/kernel/debug/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";

/*
 * 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)
		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";
		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) *
			 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 =