LXR linux/drivers/usb/serial/usb

   1/*
   2 * USB Debug cable driver
   3 *
   4 * Copyright (C) 2006 Greg Kroah-Hartman <greg@kroah.com>
   5 *
   6 *      This program is free software; you can redistribute it and/or
   7 *      modify it under the terms of the GNU General Public License version
   8 *      2 as published by the Free Software Foundation.
   9 */
  10
  11#include <linux/gfp.h>
  12#include <linux/kernel.h>
  13#include <linux/init.h>
  14#include <linux/tty.h>
  15#include <linux/module.h>
  16#include <linux/usb.h>
  17#include <linux/usb/serial.h>
  18
  19#define USB_DEBUG_MAX_PACKET_SIZE       8
  20#define USB_DEBUG_BRK_SIZE              8
  21static char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = {
  22        0x00,
  23        0xff,
  24        0x01,
  25        0xfe,
  26        0x00,
  27        0xfe,
  28        0x01,
  29        0xff,
  30};
  31
  32static const struct usb_device_id id_table[] = {
  33        { USB_DEVICE(0x0525, 0x127a) },
  34        { },
  35};
  36MODULE_DEVICE_TABLE(usb, id_table);
  37
  38/* This HW really does not support a serial break, so one will be
  39 * emulated when ever the break state is set to true.
  40 */
  41static void usb_debug_break_ctl(struct tty_struct *tty, int break_state)
  42{
  43        struct usb_serial_port *port = tty->driver_data;
  44        if (!break_state)
  45                return;
  46        usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
  47}
  48
  49static void usb_debug_process_read_urb(struct urb *urb)
  50{
  51        struct usb_serial_port *port = urb->context;
  52
  53        if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
  54                memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
  55                                                USB_DEBUG_BRK_SIZE) == 0) {
  56                usb_serial_handle_break(port);
  57                return;
  58        }
  59
  60        usb_serial_generic_process_read_urb(urb);
  61}
  62
  63static struct usb_serial_driver debug_device = {
  64        .driver = {
  65                .owner =        THIS_MODULE,
  66                .name =         "debug",
  67        },
  68        .id_table =             id_table,
  69        .num_ports =            1,
  70        .bulk_out_size =        USB_DEBUG_MAX_PACKET_SIZE,
  71        .break_ctl =            usb_debug_break_ctl,
  72        .process_read_urb =     usb_debug_process_read_urb,
  73};
  74
  75static struct usb_serial_driver * const serial_drivers[] = {
  76        &debug_device, NULL
  77};
  78
  79module_usb_serial_driver(serial_drivers, id_table);
  80MODULE_LICENSE("GPL");
  81