xref: /linux/drivers/usb/serial/omninet.c (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
1 /*
2  * USB ZyXEL omni.net LCD PLUS driver
3  *
4  *	This program is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU General Public License version
6  *	2 as published by the Free Software Foundation.
7  *
8  * See Documentation/usb/usb-serial.txt for more information on using this
9  * driver
10  *
11  * Please report both successes and troubles to the author at omninet@kroah.com
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <linux/tty.h>
19 #include <linux/tty_driver.h>
20 #include <linux/tty_flip.h>
21 #include <linux/module.h>
22 #include <linux/uaccess.h>
23 #include <linux/usb.h>
24 #include <linux/usb/serial.h>
25 
26 #define DRIVER_AUTHOR "Alessandro Zummo"
27 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
28 
29 #define ZYXEL_VENDOR_ID		0x0586
30 #define ZYXEL_OMNINET_ID	0x1000
31 /* This one seems to be a re-branded ZyXEL device */
32 #define BT_IGNITIONPRO_ID	0x2000
33 
34 /* function prototypes */
35 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
36 static void omninet_close(struct usb_serial_port *port);
37 static void omninet_read_bulk_callback(struct urb *urb);
38 static void omninet_write_bulk_callback(struct urb *urb);
39 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
40 				const unsigned char *buf, int count);
41 static int  omninet_write_room(struct tty_struct *tty);
42 static void omninet_disconnect(struct usb_serial *serial);
43 static int omninet_port_probe(struct usb_serial_port *port);
44 static int omninet_port_remove(struct usb_serial_port *port);
45 
46 static const struct usb_device_id id_table[] = {
47 	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
48 	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
49 	{ }						/* Terminating entry */
50 };
51 MODULE_DEVICE_TABLE(usb, id_table);
52 
53 static struct usb_serial_driver zyxel_omninet_device = {
54 	.driver = {
55 		.owner =	THIS_MODULE,
56 		.name =		"omninet",
57 	},
58 	.description =		"ZyXEL - omni.net lcd plus usb",
59 	.id_table =		id_table,
60 	.num_ports =		1,
61 	.port_probe =		omninet_port_probe,
62 	.port_remove =		omninet_port_remove,
63 	.open =			omninet_open,
64 	.close =		omninet_close,
65 	.write =		omninet_write,
66 	.write_room =		omninet_write_room,
67 	.read_bulk_callback =	omninet_read_bulk_callback,
68 	.write_bulk_callback =	omninet_write_bulk_callback,
69 	.disconnect =		omninet_disconnect,
70 };
71 
72 static struct usb_serial_driver * const serial_drivers[] = {
73 	&zyxel_omninet_device, NULL
74 };
75 
76 
77 /* The protocol.
78  *
79  * The omni.net always exchange 64 bytes of data with the host. The first
80  * four bytes are the control header, you can see it in the above structure.
81  *
82  * oh_seq is a sequence number. Don't know if/how it's used.
83  * oh_len is the length of the data bytes in the packet.
84  * oh_xxx Bit-mapped, related to handshaking and status info.
85  *	I normally set it to 0x03 in trasmitted frames.
86  *	7: Active when the TA is in a CONNECTed state.
87  *	6: unknown
88  *	5: handshaking, unknown
89  *	4: handshaking, unknown
90  *	3: unknown, usually 0
91  *	2: unknown, usually 0
92  *	1: handshaking, unknown, usually set to 1 in trasmitted frames
93  *	0: handshaking, unknown, usually set to 1 in trasmitted frames
94  * oh_pad Probably a pad byte.
95  *
96  * After the header you will find data bytes if oh_len was greater than zero.
97  *
98  */
99 
100 struct omninet_header {
101 	__u8	oh_seq;
102 	__u8	oh_len;
103 	__u8	oh_xxx;
104 	__u8	oh_pad;
105 };
106 
107 struct omninet_data {
108 	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
109 };
110 
111 static int omninet_port_probe(struct usb_serial_port *port)
112 {
113 	struct omninet_data *od;
114 
115 	od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
116 	if (!od)
117 		return -ENOMEM;
118 
119 	usb_set_serial_port_data(port, od);
120 
121 	return 0;
122 }
123 
124 static int omninet_port_remove(struct usb_serial_port *port)
125 {
126 	struct omninet_data *od;
127 
128 	od = usb_get_serial_port_data(port);
129 	kfree(od);
130 
131 	return 0;
132 }
133 
134 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
135 {
136 	struct usb_serial	*serial = port->serial;
137 	struct usb_serial_port	*wport;
138 	int			result = 0;
139 
140 	wport = serial->port[1];
141 	tty_port_tty_set(&wport->port, tty);
142 
143 	/* Start reading from the device */
144 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
145 	if (result)
146 		dev_err(&port->dev,
147 			"%s - failed submitting read urb, error %d\n",
148 			__func__, result);
149 	return result;
150 }
151 
152 static void omninet_close(struct usb_serial_port *port)
153 {
154 	usb_kill_urb(port->read_urb);
155 }
156 
157 
158 #define OMNINET_DATAOFFSET	0x04
159 #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
160 #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
161 
162 static void omninet_read_bulk_callback(struct urb *urb)
163 {
164 	struct usb_serial_port 	*port 	= urb->context;
165 	unsigned char 		*data 	= urb->transfer_buffer;
166 	struct omninet_header 	*header = (struct omninet_header *) &data[0];
167 	int status = urb->status;
168 	int result;
169 
170 	if (status) {
171 		dev_dbg(&port->dev, "%s - nonzero read bulk status received: %d\n",
172 			__func__, status);
173 		return;
174 	}
175 
176 	if (urb->actual_length && header->oh_len) {
177 		tty_insert_flip_string(&port->port, data + OMNINET_DATAOFFSET,
178 				header->oh_len);
179 		tty_flip_buffer_push(&port->port);
180 	}
181 
182 	/* Continue trying to always read  */
183 	result = usb_submit_urb(urb, GFP_ATOMIC);
184 	if (result)
185 		dev_err(&port->dev,
186 			"%s - failed resubmitting read urb, error %d\n",
187 			__func__, result);
188 }
189 
190 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
191 					const unsigned char *buf, int count)
192 {
193 	struct usb_serial *serial = port->serial;
194 	struct usb_serial_port *wport = serial->port[1];
195 
196 	struct omninet_data *od = usb_get_serial_port_data(port);
197 	struct omninet_header *header = (struct omninet_header *)
198 					wport->write_urb->transfer_buffer;
199 
200 	int			result;
201 
202 	if (count == 0) {
203 		dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
204 		return 0;
205 	}
206 
207 	if (!test_and_clear_bit(0, &port->write_urbs_free)) {
208 		dev_dbg(&port->dev, "%s - already writing\n", __func__);
209 		return 0;
210 	}
211 
212 	count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
213 
214 	memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
215 								buf, count);
216 
217 	usb_serial_debug_data(&port->dev, __func__, count,
218 			      wport->write_urb->transfer_buffer);
219 
220 	header->oh_seq 	= od->od_outseq++;
221 	header->oh_len 	= count;
222 	header->oh_xxx  = 0x03;
223 	header->oh_pad 	= 0x00;
224 
225 	/* send the data out the bulk port, always 64 bytes */
226 	wport->write_urb->transfer_buffer_length = 64;
227 
228 	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
229 	if (result) {
230 		set_bit(0, &wport->write_urbs_free);
231 		dev_err_console(port,
232 			"%s - failed submitting write urb, error %d\n",
233 			__func__, result);
234 	} else
235 		result = count;
236 
237 	return result;
238 }
239 
240 
241 static int omninet_write_room(struct tty_struct *tty)
242 {
243 	struct usb_serial_port *port = tty->driver_data;
244 	struct usb_serial 	*serial = port->serial;
245 	struct usb_serial_port 	*wport 	= serial->port[1];
246 
247 	int room = 0; /* Default: no room */
248 
249 	if (test_bit(0, &wport->write_urbs_free))
250 		room = wport->bulk_out_size - OMNINET_HEADERLEN;
251 
252 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
253 
254 	return room;
255 }
256 
257 static void omninet_write_bulk_callback(struct urb *urb)
258 {
259 /*	struct omninet_header	*header = (struct omninet_header  *)
260 						urb->transfer_buffer; */
261 	struct usb_serial_port 	*port   =  urb->context;
262 	int status = urb->status;
263 
264 	set_bit(0, &port->write_urbs_free);
265 	if (status) {
266 		dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
267 			__func__, status);
268 		return;
269 	}
270 
271 	usb_serial_port_softint(port);
272 }
273 
274 
275 static void omninet_disconnect(struct usb_serial *serial)
276 {
277 	struct usb_serial_port *wport = serial->port[1];
278 
279 	usb_kill_urb(wport->write_urb);
280 }
281 
282 module_usb_serial_driver(serial_drivers, id_table);
283 
284 MODULE_AUTHOR(DRIVER_AUTHOR);
285 MODULE_DESCRIPTION(DRIVER_DESC);
286 MODULE_LICENSE("GPL");
287