xref: /linux/drivers/usb/serial/omninet.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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  * (05/30/2001) gkh
14  *	switched from using spinlock to a semaphore, which fixes lots of
15  *	problems.
16  *
17  * (04/08/2001) gb
18  *	Identify version on module load.
19  *
20  * (11/01/2000) Adam J. Richter
21  *	usb_device_id table support
22  *
23  * (10/05/2000) gkh
24  *	Fixed bug with urb->dev not being set properly, now that the usb
25  *	core needs it.
26  *
27  * (08/28/2000) gkh
28  *	Added locks for SMP safeness.
29  *	Fixed MOD_INC and MOD_DEC logic and the ability to open a port more
30  *	than once.
31  *	Fixed potential race in omninet_write_bulk_callback
32  *
33  * (07/19/2000) gkh
34  *	Added module_init and module_exit functions to handle the fact that this
35  *	driver is a loadable module now.
36  *
37  */
38 
39 #include <linux/kernel.h>
40 #include <linux/errno.h>
41 #include <linux/init.h>
42 #include <linux/slab.h>
43 #include <linux/tty.h>
44 #include <linux/tty_driver.h>
45 #include <linux/tty_flip.h>
46 #include <linux/module.h>
47 #include <linux/spinlock.h>
48 #include <linux/uaccess.h>
49 #include <linux/usb.h>
50 #include <linux/usb/serial.h>
51 
52 static int debug;
53 
54 /*
55  * Version Information
56  */
57 #define DRIVER_VERSION "v1.1"
58 #define DRIVER_AUTHOR "Alessandro Zummo"
59 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
60 
61 #define ZYXEL_VENDOR_ID		0x0586
62 #define ZYXEL_OMNINET_ID	0x1000
63 /* This one seems to be a re-branded ZyXEL device */
64 #define BT_IGNITIONPRO_ID	0x2000
65 
66 /* function prototypes */
67 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
68 static void omninet_close(struct usb_serial_port *port);
69 static void omninet_read_bulk_callback(struct urb *urb);
70 static void omninet_write_bulk_callback(struct urb *urb);
71 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
72 				const unsigned char *buf, int count);
73 static int  omninet_write_room(struct tty_struct *tty);
74 static void omninet_disconnect(struct usb_serial *serial);
75 static void omninet_release(struct usb_serial *serial);
76 static int omninet_attach(struct usb_serial *serial);
77 
78 static const struct usb_device_id id_table[] = {
79 	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
80 	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
81 	{ }						/* Terminating entry */
82 };
83 
84 MODULE_DEVICE_TABLE(usb, id_table);
85 
86 static struct usb_driver omninet_driver = {
87 	.name =		"omninet",
88 	.probe =	usb_serial_probe,
89 	.disconnect =	usb_serial_disconnect,
90 	.id_table =	id_table,
91 	.no_dynamic_id = 	1,
92 };
93 
94 
95 static struct usb_serial_driver zyxel_omninet_device = {
96 	.driver = {
97 		.owner =	THIS_MODULE,
98 		.name =		"omninet",
99 	},
100 	.description =		"ZyXEL - omni.net lcd plus usb",
101 	.usb_driver =		&omninet_driver,
102 	.id_table =		id_table,
103 	.num_ports =		1,
104 	.attach =		omninet_attach,
105 	.open =			omninet_open,
106 	.close =		omninet_close,
107 	.write =		omninet_write,
108 	.write_room =		omninet_write_room,
109 	.read_bulk_callback =	omninet_read_bulk_callback,
110 	.write_bulk_callback =	omninet_write_bulk_callback,
111 	.disconnect =		omninet_disconnect,
112 	.release =		omninet_release,
113 };
114 
115 
116 /* The protocol.
117  *
118  * The omni.net always exchange 64 bytes of data with the host. The first
119  * four bytes are the control header, you can see it in the above structure.
120  *
121  * oh_seq is a sequence number. Don't know if/how it's used.
122  * oh_len is the length of the data bytes in the packet.
123  * oh_xxx Bit-mapped, related to handshaking and status info.
124  *	I normally set it to 0x03 in trasmitted frames.
125  *	7: Active when the TA is in a CONNECTed state.
126  *	6: unknown
127  *	5: handshaking, unknown
128  *	4: handshaking, unknown
129  *	3: unknown, usually 0
130  *	2: unknown, usually 0
131  *	1: handshaking, unknown, usually set to 1 in trasmitted frames
132  *	0: handshaking, unknown, usually set to 1 in trasmitted frames
133  * oh_pad Probably a pad byte.
134  *
135  * After the header you will find data bytes if oh_len was greater than zero.
136  *
137  */
138 
139 struct omninet_header {
140 	__u8	oh_seq;
141 	__u8	oh_len;
142 	__u8	oh_xxx;
143 	__u8	oh_pad;
144 };
145 
146 struct omninet_data {
147 	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
148 };
149 
150 static int omninet_attach(struct usb_serial *serial)
151 {
152 	struct omninet_data *od;
153 	struct usb_serial_port *port = serial->port[0];
154 
155 	od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
156 	if (!od) {
157 		dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n",
158 			__func__, sizeof(struct omninet_data));
159 		return -ENOMEM;
160 	}
161 	usb_set_serial_port_data(port, od);
162 	return 0;
163 }
164 
165 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
166 {
167 	struct usb_serial	*serial = port->serial;
168 	struct usb_serial_port	*wport;
169 	int			result = 0;
170 
171 	dbg("%s - port %d", __func__, port->number);
172 
173 	wport = serial->port[1];
174 	tty_port_tty_set(&wport->port, tty);
175 
176 	/* Start reading from the device */
177 	usb_fill_bulk_urb(port->read_urb, serial->dev,
178 			usb_rcvbulkpipe(serial->dev,
179 				port->bulk_in_endpointAddress),
180 			port->read_urb->transfer_buffer,
181 			port->read_urb->transfer_buffer_length,
182 			omninet_read_bulk_callback, port);
183 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
184 	if (result)
185 		dev_err(&port->dev,
186 			"%s - failed submitting read urb, error %d\n",
187 			__func__, result);
188 	return result;
189 }
190 
191 static void omninet_close(struct usb_serial_port *port)
192 {
193 	dbg("%s - port %d", __func__, port->number);
194 	usb_kill_urb(port->read_urb);
195 }
196 
197 
198 #define OMNINET_DATAOFFSET	0x04
199 #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
200 #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
201 
202 static void omninet_read_bulk_callback(struct urb *urb)
203 {
204 	struct usb_serial_port 	*port 	= urb->context;
205 	unsigned char 		*data 	= urb->transfer_buffer;
206 	struct omninet_header 	*header = (struct omninet_header *) &data[0];
207 	int status = urb->status;
208 	int result;
209 	int i;
210 
211 	dbg("%s - port %d", __func__, port->number);
212 
213 	if (status) {
214 		dbg("%s - nonzero read bulk status received: %d",
215 		    __func__, status);
216 		return;
217 	}
218 
219 	if (debug && header->oh_xxx != 0x30) {
220 		if (urb->actual_length) {
221 			printk(KERN_DEBUG "%s: omninet_read %d: ",
222 			       __FILE__, header->oh_len);
223 			for (i = 0; i < (header->oh_len +
224 						OMNINET_HEADERLEN); i++)
225 				printk("%.2x ", data[i]);
226 			printk("\n");
227 		}
228 	}
229 
230 	if (urb->actual_length && header->oh_len) {
231 		struct tty_struct *tty = tty_port_tty_get(&port->port);
232 		tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
233 							header->oh_len);
234 		tty_flip_buffer_push(tty);
235 		tty_kref_put(tty);
236 	}
237 
238 	/* Continue trying to always read  */
239 	usb_fill_bulk_urb(urb, port->serial->dev,
240 			usb_rcvbulkpipe(port->serial->dev,
241 					port->bulk_in_endpointAddress),
242 			urb->transfer_buffer, urb->transfer_buffer_length,
243 			omninet_read_bulk_callback, port);
244 	result = usb_submit_urb(urb, GFP_ATOMIC);
245 	if (result)
246 		dev_err(&port->dev,
247 			"%s - failed resubmitting read urb, error %d\n",
248 			__func__, result);
249 }
250 
251 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
252 					const unsigned char *buf, int count)
253 {
254 	struct usb_serial *serial = port->serial;
255 	struct usb_serial_port *wport = serial->port[1];
256 
257 	struct omninet_data *od = usb_get_serial_port_data(port);
258 	struct omninet_header *header = (struct omninet_header *)
259 					wport->write_urb->transfer_buffer;
260 
261 	int			result;
262 
263 	dbg("%s - port %d", __func__, port->number);
264 
265 	if (count == 0) {
266 		dbg("%s - write request of 0 bytes", __func__);
267 		return 0;
268 	}
269 
270 	spin_lock_bh(&wport->lock);
271 	if (wport->write_urb_busy) {
272 		spin_unlock_bh(&wport->lock);
273 		dbg("%s - already writing", __func__);
274 		return 0;
275 	}
276 	wport->write_urb_busy = 1;
277 	spin_unlock_bh(&wport->lock);
278 
279 	count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
280 
281 	memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
282 								buf, count);
283 
284 	usb_serial_debug_data(debug, &port->dev, __func__, count,
285 					wport->write_urb->transfer_buffer);
286 
287 	header->oh_seq 	= od->od_outseq++;
288 	header->oh_len 	= count;
289 	header->oh_xxx  = 0x03;
290 	header->oh_pad 	= 0x00;
291 
292 	/* send the data out the bulk port, always 64 bytes */
293 	wport->write_urb->transfer_buffer_length = 64;
294 
295 	wport->write_urb->dev = serial->dev;
296 	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
297 	if (result) {
298 		wport->write_urb_busy = 0;
299 		dev_err(&port->dev,
300 			"%s - failed submitting write urb, error %d\n",
301 			__func__, result);
302 	} else
303 		result = count;
304 
305 	return result;
306 }
307 
308 
309 static int omninet_write_room(struct tty_struct *tty)
310 {
311 	struct usb_serial_port *port = tty->driver_data;
312 	struct usb_serial 	*serial = port->serial;
313 	struct usb_serial_port 	*wport 	= serial->port[1];
314 
315 	int room = 0; /* Default: no room */
316 
317 	/* FIXME: no consistent locking for write_urb_busy */
318 	if (wport->write_urb_busy)
319 		room = wport->bulk_out_size - OMNINET_HEADERLEN;
320 
321 	dbg("%s - returns %d", __func__, room);
322 
323 	return room;
324 }
325 
326 static void omninet_write_bulk_callback(struct urb *urb)
327 {
328 /*	struct omninet_header	*header = (struct omninet_header  *)
329 						urb->transfer_buffer; */
330 	struct usb_serial_port 	*port   =  urb->context;
331 	int status = urb->status;
332 
333 	dbg("%s - port %0x", __func__, port->number);
334 
335 	port->write_urb_busy = 0;
336 	if (status) {
337 		dbg("%s - nonzero write bulk status received: %d",
338 		    __func__, status);
339 		return;
340 	}
341 
342 	usb_serial_port_softint(port);
343 }
344 
345 
346 static void omninet_disconnect(struct usb_serial *serial)
347 {
348 	struct usb_serial_port *wport = serial->port[1];
349 
350 	dbg("%s", __func__);
351 
352 	usb_kill_urb(wport->write_urb);
353 }
354 
355 
356 static void omninet_release(struct usb_serial *serial)
357 {
358 	struct usb_serial_port *port = serial->port[0];
359 
360 	dbg("%s", __func__);
361 
362 	kfree(usb_get_serial_port_data(port));
363 }
364 
365 
366 static int __init omninet_init(void)
367 {
368 	int retval;
369 	retval = usb_serial_register(&zyxel_omninet_device);
370 	if (retval)
371 		goto failed_usb_serial_register;
372 	retval = usb_register(&omninet_driver);
373 	if (retval)
374 		goto failed_usb_register;
375 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
376 	       DRIVER_DESC "\n");
377 	return 0;
378 failed_usb_register:
379 	usb_serial_deregister(&zyxel_omninet_device);
380 failed_usb_serial_register:
381 	return retval;
382 }
383 
384 
385 static void __exit omninet_exit(void)
386 {
387 	usb_deregister(&omninet_driver);
388 	usb_serial_deregister(&zyxel_omninet_device);
389 }
390 
391 
392 module_init(omninet_init);
393 module_exit(omninet_exit);
394 
395 MODULE_AUTHOR(DRIVER_AUTHOR);
396 MODULE_DESCRIPTION(DRIVER_DESC);
397 MODULE_LICENSE("GPL");
398 
399 module_param(debug, bool, S_IRUGO | S_IWUSR);
400 MODULE_PARM_DESC(debug, "Debug enabled or not");
401