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/tty.h>
  14#include <linux/module.h>
  15#include <linux/usb.h>
  16#include <linux/usb/serial.h>
  17
  18#define USB_DEBUG_MAX_PACKET_SIZE       8
  19#define USB_DEBUG_BRK_SIZE              8
  20static char USB_DEBUG_BRK[USB_DEBUG_BRK_SIZE] = {
  21        0x00,
  22        0xff,
  23        0x01,
  24        0xfe,
  25        0x00,
  26        0xfe,
  27        0x01,
  28        0xff,
  29};
  30
  31static const struct usb_device_id id_table[] = {
  32        { USB_DEVICE(0x0525, 0x127a) },
  33        { },
  34};
  35MODULE_DEVICE_TABLE(usb, id_table);
  36
  37/* This HW really does not support a serial break, so one will be
  38 * emulated when ever the break state is set to true.
  39 */
  40static void usb_debug_break_ctl(struct tty_struct *tty, int break_state)
  41{
  42        struct usb_serial_port *port = tty->driver_data;
  43        if (!break_state)
  44                return;
  45        usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
  46}
  47
  48static void usb_debug_process_read_urb(struct urb *urb)
  49{
  50        struct usb_serial_port *port = urb->context;
  51
  52        if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
  53                memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
  54                                                USB_DEBUG_BRK_SIZE) == 0) {
  55                usb_serial_handle_break(port);
  56                return;
  57        }
  58
  59        usb_serial_generic_process_read_urb(urb);
  60}
  61
  62static struct usb_serial_driver debug_device = {
  63        .driver = {
  64                .owner =        THIS_MODULE,
  65                .name =         "debug",
  66        },
  67        .id_table =             id_table,
  68        .num_ports =            1,
  69        .bulk_out_size =        USB_DEBUG_MAX_PACKET_SIZE,
  70        .break_ctl =            usb_debug_break_ctl,
  71        .process_read_urb =     usb_debug_process_read_urb,
  72};
  73
  74static struct usb_serial_driver * const serial_drivers[] = {
  75        &debug_device, NULL
  76};
  77
  78module_usb_serial_driver(serial_drivers, id_table);
  79MODULE_LICENSE("GPL");
  80