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};
44
45/* This HW really does not support a serial break, so one will be
46 * emulated when ever the break state is set to true.
47 */
48static void usb_debug_break_ctl(struct tty_struct *tty, int break_state)
49{
50	struct usb_serial_port *port = tty->driver_data;
51	if (!break_state)
52		return;
53	usb_serial_generic_write(tty, port, USB_DEBUG_BRK, USB_DEBUG_BRK_SIZE);
54}
55
56static void usb_debug_process_read_urb(struct urb *urb)
57{
58	struct usb_serial_port *port = urb->context;
59
60	if (urb->actual_length == USB_DEBUG_BRK_SIZE &&
61		memcmp(urb->transfer_buffer, USB_DEBUG_BRK,
62						USB_DEBUG_BRK_SIZE) == 0) {
63		usb_serial_handle_break(port);
64		return;
65	}
66
67	usb_serial_generic_process_read_urb(urb);
68}
69
70static struct usb_serial_driver debug_device = {
71	.driver = {
72		.owner =	THIS_MODULE,
73		.name =		"debug",
74	},
75	.id_table =		id_table,
76	.num_ports =		1,
77	.bulk_out_size =	USB_DEBUG_MAX_PACKET_SIZE,
78	.break_ctl =		usb_debug_break_ctl,
79	.process_read_urb =	usb_debug_process_read_urb,
80};
81
82static struct usb_serial_driver * const serial_drivers[] = {
83	&debug_device, NULL
84};
85
86module_usb_serial_driver(debug_driver, serial_drivers);
87MODULE_LICENSE("GPL");
88