xref: /linux/drivers/usb/serial/omninet.c (revision 08ec212c0f92cbf30e3ecc7349f18151714041d6)
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 /*
27  * Version Information
28  */
29 #define DRIVER_VERSION "v1.1"
30 #define DRIVER_AUTHOR "Alessandro Zummo"
31 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
32 
33 #define ZYXEL_VENDOR_ID		0x0586
34 #define ZYXEL_OMNINET_ID	0x1000
35 /* This one seems to be a re-branded ZyXEL device */
36 #define BT_IGNITIONPRO_ID	0x2000
37 
38 /* function prototypes */
39 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
40 static void omninet_close(struct usb_serial_port *port);
41 static void omninet_read_bulk_callback(struct urb *urb);
42 static void omninet_write_bulk_callback(struct urb *urb);
43 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
44 				const unsigned char *buf, int count);
45 static int  omninet_write_room(struct tty_struct *tty);
46 static void omninet_disconnect(struct usb_serial *serial);
47 static void omninet_release(struct usb_serial *serial);
48 static int omninet_attach(struct usb_serial *serial);
49 
50 static const struct usb_device_id id_table[] = {
51 	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
52 	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
53 	{ }						/* Terminating entry */
54 };
55 MODULE_DEVICE_TABLE(usb, id_table);
56 
57 static struct usb_serial_driver zyxel_omninet_device = {
58 	.driver = {
59 		.owner =	THIS_MODULE,
60 		.name =		"omninet",
61 	},
62 	.description =		"ZyXEL - omni.net lcd plus usb",
63 	.id_table =		id_table,
64 	.num_ports =		1,
65 	.attach =		omninet_attach,
66 	.open =			omninet_open,
67 	.close =		omninet_close,
68 	.write =		omninet_write,
69 	.write_room =		omninet_write_room,
70 	.read_bulk_callback =	omninet_read_bulk_callback,
71 	.write_bulk_callback =	omninet_write_bulk_callback,
72 	.disconnect =		omninet_disconnect,
73 	.release =		omninet_release,
74 };
75 
76 static struct usb_serial_driver * const serial_drivers[] = {
77 	&zyxel_omninet_device, NULL
78 };
79 
80 
81 /* The protocol.
82  *
83  * The omni.net always exchange 64 bytes of data with the host. The first
84  * four bytes are the control header, you can see it in the above structure.
85  *
86  * oh_seq is a sequence number. Don't know if/how it's used.
87  * oh_len is the length of the data bytes in the packet.
88  * oh_xxx Bit-mapped, related to handshaking and status info.
89  *	I normally set it to 0x03 in trasmitted frames.
90  *	7: Active when the TA is in a CONNECTed state.
91  *	6: unknown
92  *	5: handshaking, unknown
93  *	4: handshaking, unknown
94  *	3: unknown, usually 0
95  *	2: unknown, usually 0
96  *	1: handshaking, unknown, usually set to 1 in trasmitted frames
97  *	0: handshaking, unknown, usually set to 1 in trasmitted frames
98  * oh_pad Probably a pad byte.
99  *
100  * After the header you will find data bytes if oh_len was greater than zero.
101  *
102  */
103 
104 struct omninet_header {
105 	__u8	oh_seq;
106 	__u8	oh_len;
107 	__u8	oh_xxx;
108 	__u8	oh_pad;
109 };
110 
111 struct omninet_data {
112 	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
113 };
114 
115 static int omninet_attach(struct usb_serial *serial)
116 {
117 	struct omninet_data *od;
118 	struct usb_serial_port *port = serial->port[0];
119 
120 	od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
121 	if (!od) {
122 		dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n",
123 			__func__, sizeof(struct omninet_data));
124 		return -ENOMEM;
125 	}
126 	usb_set_serial_port_data(port, od);
127 	return 0;
128 }
129 
130 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
131 {
132 	struct usb_serial	*serial = port->serial;
133 	struct usb_serial_port	*wport;
134 	int			result = 0;
135 
136 	wport = serial->port[1];
137 	tty_port_tty_set(&wport->port, tty);
138 
139 	/* Start reading from the device */
140 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
141 	if (result)
142 		dev_err(&port->dev,
143 			"%s - failed submitting read urb, error %d\n",
144 			__func__, result);
145 	return result;
146 }
147 
148 static void omninet_close(struct usb_serial_port *port)
149 {
150 	usb_kill_urb(port->read_urb);
151 }
152 
153 
154 #define OMNINET_DATAOFFSET	0x04
155 #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
156 #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
157 
158 static void omninet_read_bulk_callback(struct urb *urb)
159 {
160 	struct usb_serial_port 	*port 	= urb->context;
161 	unsigned char 		*data 	= urb->transfer_buffer;
162 	struct omninet_header 	*header = (struct omninet_header *) &data[0];
163 	int status = urb->status;
164 	int result;
165 
166 	if (status) {
167 		dev_dbg(&port->dev, "%s - nonzero read bulk status received: %d\n",
168 			__func__, status);
169 		return;
170 	}
171 
172 	if (urb->actual_length && header->oh_len) {
173 		struct tty_struct *tty = tty_port_tty_get(&port->port);
174 		if (tty) {
175 			tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
176 							header->oh_len);
177 			tty_flip_buffer_push(tty);
178 			tty_kref_put(tty);
179 		}
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 
283 static void omninet_release(struct usb_serial *serial)
284 {
285 	struct usb_serial_port *port = serial->port[0];
286 
287 	kfree(usb_get_serial_port_data(port));
288 }
289 
290 module_usb_serial_driver(serial_drivers, id_table);
291 
292 MODULE_AUTHOR(DRIVER_AUTHOR);
293 MODULE_DESCRIPTION(DRIVER_DESC);
294 MODULE_LICENSE("GPL");
295