aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/omninet.c
blob: a180b17d24323b074aee19e33bf0f497ad271d8a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
/*
 * USB ZyXEL omni.net LCD PLUS driver
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License version
 *	2 as published by the Free Software Foundation.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this
 * driver
 *
 * Please report both successes and troubles to the author at omninet@kroah.com
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

#define DRIVER_AUTHOR "Alessandro Zummo"
#define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"

#define ZYXEL_VENDOR_ID		0x0586
#define ZYXEL_OMNINET_ID	0x1000
/* This one seems to be a re-branded ZyXEL device */
#define BT_IGNITIONPRO_ID	0x2000

/* function prototypes */
static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
static void omninet_process_read_urb(struct urb *urb);
static void omninet_write_bulk_callback(struct urb *urb);
static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
				const unsigned char *buf, int count);
static int  omninet_write_room(struct tty_struct *tty);
static void omninet_disconnect(struct usb_serial *serial);
static int omninet_attach(struct usb_serial *serial);
static int omninet_port_probe(struct usb_serial_port *port);
static int omninet_port_remove(struct usb_serial_port *port);

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
	{ }						/* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_serial_driver zyxel_omninet_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"omninet",
	},
	.description =		"ZyXEL - omni.net lcd plus usb",
	.id_table =		id_table,
	.num_ports =		1,
	.attach =		omninet_attach,
	.port_probe =		omninet_port_probe,
	.port_remove =		omninet_port_remove,
	.open =			omninet_open,
	.write =		omninet_write,
	.write_room =		omninet_write_room,
	.write_bulk_callback =	omninet_write_bulk_callback,
	.process_read_urb =	omninet_process_read_urb,
	.disconnect =		omninet_disconnect,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&zyxel_omninet_device, NULL
};


/*
 * The protocol.
 *
 * The omni.net always exchange 64 bytes of data with the host. The first
 * four bytes are the control header.
 *
 * oh_seq is a sequence number. Don't know if/how it's used.
 * oh_len is the length of the data bytes in the packet.
 * oh_xxx Bit-mapped, related to handshaking and status info.
 *	I normally set it to 0x03 in transmitted frames.
 *	7: Active when the TA is in a CONNECTed state.
 *	6: unknown
 *	5: handshaking, unknown
 *	4: handshaking, unknown
 *	3: unknown, usually 0
 *	2: unknown, usually 0
 *	1: handshaking, unknown, usually set to 1 in transmitted frames
 *	0: handshaking, unknown, usually set to 1 in transmitted frames
 * oh_pad Probably a pad byte.
 *
 * After the header you will find data bytes if oh_len was greater than zero.
 */
struct omninet_header {
	__u8	oh_seq;
	__u8	oh_len;
	__u8	oh_xxx;
	__u8	oh_pad;
};

struct omninet_data {
	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
};

static int omninet_attach(struct usb_serial *serial)
{
	/* The second bulk-out endpoint is used for writing. */
	if (serial->num_bulk_out < 2) {
		dev_err(&serial->interface->dev, "missing endpoints\n");
		return -ENODEV;
	}

	return 0;
}

static int omninet_port_probe(struct usb_serial_port *port)
{
	struct omninet_data *od;

	od = kzalloc(sizeof(*od), GFP_KERNEL);
	if (!od)
		return -ENOMEM;

	usb_set_serial_port_data(port, od);

	return 0;
}

static int omninet_port_remove(struct usb_serial_port *port)
{
	struct omninet_data *od;

	od = usb_get_serial_port_data(port);
	kfree(od);

	return 0;
}

static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	struct usb_serial	*serial = port->serial;
	struct usb_serial_port	*wport;

	wport = serial->port[1];
	tty_port_tty_set(&wport->port, tty);

	return usb_serial_generic_open(tty, port);
}

#define OMNINET_HEADERLEN	4
#define OMNINET_BULKOUTSIZE	64
#define OMNINET_PAYLOADSIZE	(OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)

static void omninet_process_read_urb(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	const struct omninet_header *hdr = urb->transfer_buffer;
	const unsigned char *data;
	size_t data_len;

	if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
		return;

	data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
	data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
								hdr->oh_len);
	tty_insert_flip_string(&port->port, data, data_len);
	tty_flip_buffer_push(&port->port);
}

static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
					const unsigned char *buf, int count)
{
	struct usb_serial *serial = port->serial;
	struct usb_serial_port *wport = serial->port[1];

	struct omninet_data *od = usb_get_serial_port_data(port);
	struct omninet_header *header = (struct omninet_header *)
					wport->write_urb->transfer_buffer;

	int			result;

	if (count == 0) {
		dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
		return 0;
	}

	if (!test_and_clear_bit(0, &port->write_urbs_free)) {
		dev_dbg(&port->dev, "%s - already writing\n", __func__);
		return 0;
	}

	count = (count > OMNINET_PAYLOADSIZE) ? OMNINET_PAYLOADSIZE : count;

	memcpy(wport->write_urb->transfer_buffer + OMNINET_HEADERLEN,
								buf, count);

	usb_serial_debug_data(&port->dev, __func__, count,
			      wport->write_urb->transfer_buffer);

	header->oh_seq 	= od->od_outseq++;
	header->oh_len 	= count;
	header->oh_xxx  = 0x03;
	header->oh_pad 	= 0x00;

	/* send the data out the bulk port, always 64 bytes */
	wport->write_urb->transfer_buffer_length = OMNINET_BULKOUTSIZE;

	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
	if (result) {
		set_bit(0, &wport->write_urbs_free);
		dev_err_console(port,
			"%s - failed submitting write urb, error %d\n",
			__func__, result);
	} else
		result = count;

	return result;
}


static int omninet_write_room(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct usb_serial 	*serial = port->serial;
	struct usb_serial_port 	*wport 	= serial->port[1];

	int room = 0; /* Default: no room */

	if (test_bit(0, &wport->write_urbs_free))
		room = wport->bulk_out_size - OMNINET_HEADERLEN;

	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);

	return room;
}

static void omninet_write_bulk_callback(struct urb *urb)
{
/*	struct omninet_header	*header = (struct omninet_header  *)
						urb->transfer_buffer; */
	struct usb_serial_port 	*port   =  urb->context;
	int status = urb->status;

	set_bit(0, &port->write_urbs_free);
	if (status) {
		dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
			__func__, status);
		return;
	}

	usb_serial_port_softint(port);
}


static void omninet_disconnect(struct usb_serial *serial)
{
	struct usb_serial_port *wport = serial->port[1];

	usb_kill_urb(wport->write_urb);
}

module_usb_serial_driver(serial_drivers, id_table);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");