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
  38static struct usb_driver debug_driver = {
  39        .name =         "debug",
  40        .probe =        usb_serial_probe,
  41        .disconnect =   usb_serial_disconnect,
  42        .id_table =     id_table,
  43        .no_dynamic_id =        1,
  44};
  45
  46/* This HW really does not support a serial break, so one will be
  47 * emulated when ever the break state is set to true.
  48 */
  49static void usb_debug_break_ctl(struct tty_struct *tty, int break_state)
  50{
  51        struct usb_serial_port *port = tty->driver_data;
  52        if (!break_state)
  53                return;
  54        usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
  55}
  56
  57static void usb_debug_read_bulk_callback(struct urb *urb)
  58{
  59        struct usb_serial_port *port = urb->context;
  60
  61        if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
  62            memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
  63                   USB_DEBUG_BRK_SIZE) == 0) {
  64                usb_serial_handle_break(port);
  65                usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
  66                return;
  67        }
  68
  69        usb_serial_generic_read_bulk_callback(urb);
  70}
  71
  72static struct usb_serial_driver debug_device = {
  73        .driver = {
  74                .owner =        THIS_MODULE,
  75                .name =         "debug",
  76        },
  77        .id_table =             id_table,
  78        .usb_driver =           &debug_driver,
  79        .num_ports =            1,
  80        .bulk_out_size =        USB_DEBUG_MAX_PACKET_SIZE,
  81        .break_ctl =            usb_debug_break_ctl,
  82        .read_bulk_callback =   usb_debug_read_bulk_callback,
  83};
  84
  85static int __init debug_init(void)
  86{
  87        int retval;
  88
  89        retval = usb_serial_register(&debug_device);
  90        if (retval)
  91                return retval;
  92        retval = usb_register(&debug_driver);
  93        if (retval)
  94                usb_serial_deregister(&debug_device);
  95        return retval;
  96}
  97
  98static void __exit debug_exit(void)
  99{
 100        usb_deregister(&debug_driver);
 101        usb_serial_deregister(&debug_device);
 102}
 103
 104module_init(debug_init);
 105module_exit(debug_exit);
 106MODULE_LICENSE("GPL");
 107