xref: /openbmc/linux/drivers/usb/serial/omninet.c (revision b627b4ed)
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 							struct file *filp);
69 static void omninet_close(struct tty_struct *tty, struct usb_serial_port *port,
70 							struct file *filp);
71 static void omninet_read_bulk_callback(struct urb *urb);
72 static void omninet_write_bulk_callback(struct urb *urb);
73 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
74 				const unsigned char *buf, int count);
75 static int  omninet_write_room(struct tty_struct *tty);
76 static void omninet_shutdown(struct usb_serial *serial);
77 static int omninet_attach(struct usb_serial *serial);
78 
79 static struct usb_device_id id_table[] = {
80 	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
81 	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
82 	{ }						/* Terminating entry */
83 };
84 
85 MODULE_DEVICE_TABLE(usb, id_table);
86 
87 static struct usb_driver omninet_driver = {
88 	.name =		"omninet",
89 	.probe =	usb_serial_probe,
90 	.disconnect =	usb_serial_disconnect,
91 	.id_table =	id_table,
92 	.no_dynamic_id = 	1,
93 };
94 
95 
96 static struct usb_serial_driver zyxel_omninet_device = {
97 	.driver = {
98 		.owner =	THIS_MODULE,
99 		.name =		"omninet",
100 	},
101 	.description =		"ZyXEL - omni.net lcd plus usb",
102 	.usb_driver =		&omninet_driver,
103 	.id_table =		id_table,
104 	.num_ports =		1,
105 	.attach =		omninet_attach,
106 	.open =			omninet_open,
107 	.close =		omninet_close,
108 	.write =		omninet_write,
109 	.write_room =		omninet_write_room,
110 	.read_bulk_callback =	omninet_read_bulk_callback,
111 	.write_bulk_callback =	omninet_write_bulk_callback,
112 	.shutdown =		omninet_shutdown,
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,
166 			struct usb_serial_port *port, struct file *filp)
167 {
168 	struct usb_serial	*serial = port->serial;
169 	struct usb_serial_port	*wport;
170 	int			result = 0;
171 
172 	dbg("%s - port %d", __func__, port->number);
173 
174 	wport = serial->port[1];
175 	tty_port_tty_set(&wport->port, tty);
176 
177 	/* Start reading from the device */
178 	usb_fill_bulk_urb(port->read_urb, serial->dev,
179 			usb_rcvbulkpipe(serial->dev,
180 				port->bulk_in_endpointAddress),
181 			port->read_urb->transfer_buffer,
182 			port->read_urb->transfer_buffer_length,
183 			omninet_read_bulk_callback, port);
184 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
185 	if (result)
186 		dev_err(&port->dev,
187 			"%s - failed submitting read urb, error %d\n",
188 			__func__, result);
189 	return result;
190 }
191 
192 static void omninet_close(struct tty_struct *tty,
193 			struct usb_serial_port *port, struct file *filp)
194 {
195 	dbg("%s - port %d", __func__, port->number);
196 	usb_kill_urb(port->read_urb);
197 }
198 
199 
200 #define OMNINET_DATAOFFSET	0x04
201 #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
202 #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
203 
204 static void omninet_read_bulk_callback(struct urb *urb)
205 {
206 	struct usb_serial_port 	*port 	= urb->context;
207 	unsigned char 		*data 	= urb->transfer_buffer;
208 	struct omninet_header 	*header = (struct omninet_header *) &data[0];
209 	int status = urb->status;
210 	int result;
211 	int i;
212 
213 	dbg("%s - port %d", __func__, port->number);
214 
215 	if (status) {
216 		dbg("%s - nonzero read bulk status received: %d",
217 		    __func__, status);
218 		return;
219 	}
220 
221 	if (debug && header->oh_xxx != 0x30) {
222 		if (urb->actual_length) {
223 			printk(KERN_DEBUG __FILE__
224 					": omninet_read %d: ", header->oh_len);
225 			for (i = 0; i < (header->oh_len +
226 						OMNINET_HEADERLEN); i++)
227 				printk("%.2x ", data[i]);
228 			printk("\n");
229 		}
230 	}
231 
232 	if (urb->actual_length && header->oh_len) {
233 		struct tty_struct *tty = tty_port_tty_get(&port->port);
234 		tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
235 							header->oh_len);
236 		tty_flip_buffer_push(tty);
237 		tty_kref_put(tty);
238 	}
239 
240 	/* Continue trying to always read  */
241 	usb_fill_bulk_urb(urb, port->serial->dev,
242 			usb_rcvbulkpipe(port->serial->dev,
243 					port->bulk_in_endpointAddress),
244 			urb->transfer_buffer, urb->transfer_buffer_length,
245 			omninet_read_bulk_callback, port);
246 	result = usb_submit_urb(urb, GFP_ATOMIC);
247 	if (result)
248 		dev_err(&port->dev,
249 			"%s - failed resubmitting read urb, error %d\n",
250 			__func__, result);
251 
252 	return;
253 }
254 
255 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
256 					const unsigned char *buf, int count)
257 {
258 	struct usb_serial *serial = port->serial;
259 	struct usb_serial_port *wport = serial->port[1];
260 
261 	struct omninet_data *od = usb_get_serial_port_data(port);
262 	struct omninet_header *header = (struct omninet_header *)
263 					wport->write_urb->transfer_buffer;
264 
265 	int			result;
266 
267 	dbg("%s - port %d", __func__, port->number);
268 
269 	if (count == 0) {
270 		dbg("%s - write request of 0 bytes", __func__);
271 		return 0;
272 	}
273 
274 	spin_lock_bh(&wport->lock);
275 	if (wport->write_urb_busy) {
276 		spin_unlock_bh(&wport->lock);
277 		dbg("%s - already writing", __func__);
278 		return 0;
279 	}
280 	wport->write_urb_busy = 1;
281 	spin_unlock_bh(&wport->lock);
282 
283 	count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
284 
285 	memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
286 								buf, count);
287 
288 	usb_serial_debug_data(debug, &port->dev, __func__, count,
289 					wport->write_urb->transfer_buffer);
290 
291 	header->oh_seq 	= od->od_outseq++;
292 	header->oh_len 	= count;
293 	header->oh_xxx  = 0x03;
294 	header->oh_pad 	= 0x00;
295 
296 	/* send the data out the bulk port, always 64 bytes */
297 	wport->write_urb->transfer_buffer_length = 64;
298 
299 	wport->write_urb->dev = serial->dev;
300 	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
301 	if (result) {
302 		wport->write_urb_busy = 0;
303 		dev_err(&port->dev,
304 			"%s - failed submitting write urb, error %d\n",
305 			__func__, result);
306 	} else
307 		result = count;
308 
309 	return result;
310 }
311 
312 
313 static int omninet_write_room(struct tty_struct *tty)
314 {
315 	struct usb_serial_port *port = tty->driver_data;
316 	struct usb_serial 	*serial = port->serial;
317 	struct usb_serial_port 	*wport 	= serial->port[1];
318 
319 	int room = 0; /* Default: no room */
320 
321 	/* FIXME: no consistent locking for write_urb_busy */
322 	if (wport->write_urb_busy)
323 		room = wport->bulk_out_size - OMNINET_HEADERLEN;
324 
325 	dbg("%s - returns %d", __func__, room);
326 
327 	return room;
328 }
329 
330 static void omninet_write_bulk_callback(struct urb *urb)
331 {
332 /*	struct omninet_header	*header = (struct omninet_header  *)
333 						urb->transfer_buffer; */
334 	struct usb_serial_port 	*port   =  urb->context;
335 	int status = urb->status;
336 
337 	dbg("%s - port %0x\n", __func__, port->number);
338 
339 	port->write_urb_busy = 0;
340 	if (status) {
341 		dbg("%s - nonzero write bulk status received: %d",
342 		    __func__, status);
343 		return;
344 	}
345 
346 	usb_serial_port_softint(port);
347 }
348 
349 
350 static void omninet_shutdown(struct usb_serial *serial)
351 {
352 	struct usb_serial_port *wport = serial->port[1];
353 	struct usb_serial_port *port = serial->port[0];
354 	dbg("%s", __func__);
355 
356 	usb_kill_urb(wport->write_urb);
357 	kfree(usb_get_serial_port_data(port));
358 }
359 
360 
361 static int __init omninet_init(void)
362 {
363 	int retval;
364 	retval = usb_serial_register(&zyxel_omninet_device);
365 	if (retval)
366 		goto failed_usb_serial_register;
367 	retval = usb_register(&omninet_driver);
368 	if (retval)
369 		goto failed_usb_register;
370 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
371 	       DRIVER_DESC "\n");
372 	return 0;
373 failed_usb_register:
374 	usb_serial_deregister(&zyxel_omninet_device);
375 failed_usb_serial_register:
376 	return retval;
377 }
378 
379 
380 static void __exit omninet_exit(void)
381 {
382 	usb_deregister(&omninet_driver);
383 	usb_serial_deregister(&zyxel_omninet_device);
384 }
385 
386 
387 module_init(omninet_init);
388 module_exit(omninet_exit);
389 
390 MODULE_AUTHOR(DRIVER_AUTHOR);
391 MODULE_DESCRIPTION(DRIVER_DESC);
392 MODULE_LICENSE("GPL");
393 
394 module_param(debug, bool, S_IRUGO | S_IWUSR);
395 MODULE_PARM_DESC(debug, "Debug enabled or not");
396