devices.c

linux core 函数例程

/*
 * devices.c
 * (C) Copyright 1999 Randy Dunlap.
 * (C) Copyright 1999,2000 Thomas Sailer <[e-mail]>. (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 <[e-mail]>
 *   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 <[e-mail]>
 *   Turned into its own filesystem
 * 2000-07-05: Ashley Montanaro <[e-mail]>
 *   Converted file reading routine to dump to buffer once
 *   per device, not per bus
 *
 * $Id: devices.c,v 1.5 2000/01/11 13:58:21 tom Exp $
 */

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/usb.h>
#include <linux/smp_lock.h>
#include <linux/usbdevice_fs.h>
#include <asm/uaccess.h>

#include "hcd.h"

#define MAX_TOPO_LEVEL		6

/* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */
#define ALLOW_SERIAL_NUMBER

static char *format_topo =
/* T:  Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=ddd MxCh=dd */
  "T:  Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%3s MxCh=%2d\n";

static char *format_string_manufacturer =
/* S:  Manufacturer=xxxx */
  "S:  Manufacturer=%.100s\n";

static char *format_string_product =
/* S:  Product=xxxx */
  "S:  Product=%.100s\n";

#ifdef ALLOW_SERIAL_NUMBER
static char *format_string_serialnumber =
/* S:  SerialNumber=xxxx */
  "S:  SerialNumber=%.100s\n";
#endif

static 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 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 char *format_device2 =
/* P:  Vendor=xxxx ProdID=xxxx Rev=xx.xx */
  "P:  Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";

static char *format_config =
/* C:  #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */
  "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";
  
static char *format_iface =
/* I:  If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
  "I:  If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";

static 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_driver_list;
 * extern struct list_head usb_bus_list;
 * However, these will come from functions that return ptrs to each of them.
 */

static DECLARE_WAIT_QUEUE_HEAD(deviceconndiscwq);
static unsigned int conndiscevcnt = 0;

/* this struct stores the poll state for <mountpoint>/devices pollers */
struct usb_device_status {
	unsigned int lastev;
};

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_HUB,			"hub"},
	{USB_CLASS_PHYSICAL,		"PID"},
	{USB_CLASS_PRINTER,		"print"},
	{USB_CLASS_MASS_STORAGE,	"stor."},
	{USB_CLASS_CDC_DATA,		"data"},
	{USB_CLASS_APP_SPEC,		"app."},
	{USB_CLASS_VENDOR_SPEC,		"vend."},
	{USB_CLASS_STILL_IMAGE,		"still"},
	{USB_CLASS_CSCID,		"scard"},
	{USB_CLASS_CONTENT_SEC,		"c-sec"},
	{-1,				"unk."}		/* leave as last */
};

/*****************************************************************/

void usbdevfs_conn_disc_event(void)
{
	wake_up(&deviceconndiscwq);
	conndiscevcnt++;
}

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, in, bandwidth = 1;

	if (start > end)
		return start;
	in = (desc->bEndpointAddress & USB_DIR_IN);
	dir = in ? 'I' : 'O';
	if (speed == USB_SPEED_HIGH) {
		switch (desc->wMaxPacketSize & (0x03 << 11)) {
		case 1 << 11:	bandwidth = 2; break;
		case 2 << 11:	bandwidth = 3; break;
		}
	}

	/* this isn't checking for illegal values */
	switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
	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 && !in)	/* uframes per NAK */
			interval = desc->bInterval;
		else
			interval = 0;
		break;
	case USB_ENDPOINT_XFER_INT:
		type = "Int.";
		if (speed == USB_SPEED_HIGH) {
			interval = 1 << (desc->bInterval - 1);
		} else
			interval = desc->bInterval;
		break;
	default:	/* "can't happen" */
		return start;
	}
	interval *= (speed == USB_SPEED_HIGH) ? 125 : 1000;
	if (interval % 1000)
		unit = 'u';
	else {
		unit = 'm';
		interval /= 1000;
	}

	start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
			 desc->bmAttributes, type,
			 (desc->wMaxPacketSize & 0x07ff) * bandwidth,
			 interval, unit);
	return start;
}

static char *usb_dump_interface_descriptor(char *start, char *end, const struct usb_interface *iface, int setno)
{
	struct usb_interface_descriptor *desc = &iface->altsetting[setno];

	if (start > end)
		return start;
	start += sprintf(start, format_iface,
			 desc->bInterfaceNumber,
			 desc->bAlternateSetting,
			 desc->bNumEndpoints,
			 desc->bInterfaceClass,
			 class_decode(desc->bInterfaceClass),
			 desc->bInterfaceSubClass,
			 desc->bInterfaceProtocol,
			 iface->driver ? iface->driver->name : "(none)");
	return start;
}

static char *usb_dump_interface(
	int speed,
	char *start,
	char *end,
	const struct usb_interface *iface,
	int setno
) {
	struct usb_interface_descriptor *desc = &iface->altsetting[setno];
	int i;

	start = usb_dump_interface_descriptor(start, end, iface, setno);
	for (i = 0; i < desc->bNumEndpoints; i++) {
		if (start > end)
			return start;
		start = usb_dump_endpoint_descriptor(speed,
				start, end, desc->endpoint + i);
	}
	return start;
}

/* TBD:
 * 0. TBDs
 * 1. marking active config and ifaces (code lists all, but should mark
 *    which ones are active, if any)
 * 2. add <halted> status to each endpoint line
 */

static char *usb_dump_config_descriptor(char *start, char *end, const struct usb_config_descriptor *desc, int active)
{
	if (start > end)
		return start;
	start += sprintf(start, format_config,
			 active ? '*' : ' ',	/* mark active/actual/current cfg. */
			 desc->bNumInterfaces,
			 desc->bConfigurationValue,
			 desc->bmAttributes,
			 desc->MaxPower * 2);
	return start;
}

static char *usb_dump_config (
	int speed,
	char *start,
	char *end,
	const struct usb_config_descriptor *config,
	int active
)
{
	int i, j;
	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, active);
	for (i = 0; i < config->bNumInterfaces; i++) {
		interface = config->interface + i;
		if (!interface)
			break;
		for (j = 0; j < interface->num_altsetting; j++) {
			if (start > end)
				return start;
			start = usb_dump_interface(speed,
					start, end, 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)
{
	if (start > end)
		return start;
	start += sprintf (start, format_device1,
			  desc->bcdUSB >> 8, desc->bcdUSB & 0xff,