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