xref: /openbmc/linux/drivers/usb/serial/omninet.c (revision 32078f915d1acab356080b144aa89fe3487f3979)
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 static bool debug;
27 
28 /*
29  * Version Information
30  */
31 #define DRIVER_VERSION "v1.1"
32 #define DRIVER_AUTHOR "Alessandro Zummo"
33 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
34 
35 #define ZYXEL_VENDOR_ID		0x0586
36 #define ZYXEL_OMNINET_ID	0x1000
37 /* This one seems to be a re-branded ZyXEL device */
38 #define BT_IGNITIONPRO_ID	0x2000
39 
40 /* function prototypes */
41 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
42 static void omninet_close(struct usb_serial_port *port);
43 static void omninet_read_bulk_callback(struct urb *urb);
44 static void omninet_write_bulk_callback(struct urb *urb);
45 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
46 				const unsigned char *buf, int count);
47 static int  omninet_write_room(struct tty_struct *tty);
48 static void omninet_disconnect(struct usb_serial *serial);
49 static void omninet_release(struct usb_serial *serial);
50 static int omninet_attach(struct usb_serial *serial);
51 
52 static const struct usb_device_id id_table[] = {
53 	{ USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
54 	{ USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
55 	{ }						/* Terminating entry */
56 };
57 
58 MODULE_DEVICE_TABLE(usb, id_table);
59 
60 static struct usb_driver omninet_driver = {
61 	.name =		"omninet",
62 	.id_table =	id_table,
63 };
64 
65 
66 static struct usb_serial_driver zyxel_omninet_device = {
67 	.driver = {
68 		.owner =	THIS_MODULE,
69 		.name =		"omninet",
70 	},
71 	.description =		"ZyXEL - omni.net lcd plus usb",
72 	.id_table =		id_table,
73 	.num_ports =		1,
74 	.attach =		omninet_attach,
75 	.open =			omninet_open,
76 	.close =		omninet_close,
77 	.write =		omninet_write,
78 	.write_room =		omninet_write_room,
79 	.read_bulk_callback =	omninet_read_bulk_callback,
80 	.write_bulk_callback =	omninet_write_bulk_callback,
81 	.disconnect =		omninet_disconnect,
82 	.release =		omninet_release,
83 };
84 
85 static struct usb_serial_driver * const serial_drivers[] = {
86 	&zyxel_omninet_device, NULL
87 };
88 
89 
90 /* The protocol.
91  *
92  * The omni.net always exchange 64 bytes of data with the host. The first
93  * four bytes are the control header, you can see it in the above structure.
94  *
95  * oh_seq is a sequence number. Don't know if/how it's used.
96  * oh_len is the length of the data bytes in the packet.
97  * oh_xxx Bit-mapped, related to handshaking and status info.
98  *	I normally set it to 0x03 in trasmitted frames.
99  *	7: Active when the TA is in a CONNECTed state.
100  *	6: unknown
101  *	5: handshaking, unknown
102  *	4: handshaking, unknown
103  *	3: unknown, usually 0
104  *	2: unknown, usually 0
105  *	1: handshaking, unknown, usually set to 1 in trasmitted frames
106  *	0: handshaking, unknown, usually set to 1 in trasmitted frames
107  * oh_pad Probably a pad byte.
108  *
109  * After the header you will find data bytes if oh_len was greater than zero.
110  *
111  */
112 
113 struct omninet_header {
114 	__u8	oh_seq;
115 	__u8	oh_len;
116 	__u8	oh_xxx;
117 	__u8	oh_pad;
118 };
119 
120 struct omninet_data {
121 	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
122 };
123 
124 static int omninet_attach(struct usb_serial *serial)
125 {
126 	struct omninet_data *od;
127 	struct usb_serial_port *port = serial->port[0];
128 
129 	od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
130 	if (!od) {
131 		dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n",
132 			__func__, sizeof(struct omninet_data));
133 		return -ENOMEM;
134 	}
135 	usb_set_serial_port_data(port, od);
136 	return 0;
137 }
138 
139 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
140 {
141 	struct usb_serial	*serial = port->serial;
142 	struct usb_serial_port	*wport;
143 	int			result = 0;
144 
145 	wport = serial->port[1];
146 	tty_port_tty_set(&wport->port, tty);
147 
148 	/* Start reading from the device */
149 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
150 	if (result)
151 		dev_err(&port->dev,
152 			"%s - failed submitting read urb, error %d\n",
153 			__func__, result);
154 	return result;
155 }
156 
157 static void omninet_close(struct usb_serial_port *port)
158 {
159 	usb_kill_urb(port->read_urb);
160 }
161 
162 
163 #define OMNINET_DATAOFFSET	0x04
164 #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
165 #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
166 
167 static void omninet_read_bulk_callback(struct urb *urb)
168 {
169 	struct usb_serial_port 	*port 	= urb->context;
170 	unsigned char 		*data 	= urb->transfer_buffer;
171 	struct omninet_header 	*header = (struct omninet_header *) &data[0];
172 	int status = urb->status;
173 	int result;
174 	int i;
175 
176 	if (status) {
177 		dbg("%s - nonzero read bulk status received: %d",
178 		    __func__, status);
179 		return;
180 	}
181 
182 	if (debug && header->oh_xxx != 0x30) {
183 		if (urb->actual_length) {
184 			printk(KERN_DEBUG "%s: omninet_read %d: ",
185 			       __FILE__, header->oh_len);
186 			for (i = 0; i < (header->oh_len +
187 						OMNINET_HEADERLEN); i++)
188 				printk("%.2x ", data[i]);
189 			printk("\n");
190 		}
191 	}
192 
193 	if (urb->actual_length && header->oh_len) {
194 		struct tty_struct *tty = tty_port_tty_get(&port->port);
195 		tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
196 							header->oh_len);
197 		tty_flip_buffer_push(tty);
198 		tty_kref_put(tty);
199 	}
200 
201 	/* Continue trying to always read  */
202 	result = usb_submit_urb(urb, GFP_ATOMIC);
203 	if (result)
204 		dev_err(&port->dev,
205 			"%s - failed resubmitting read urb, error %d\n",
206 			__func__, result);
207 }
208 
209 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
210 					const unsigned char *buf, int count)
211 {
212 	struct usb_serial *serial = port->serial;
213 	struct usb_serial_port *wport = serial->port[1];
214 
215 	struct omninet_data *od = usb_get_serial_port_data(port);
216 	struct omninet_header *header = (struct omninet_header *)
217 					wport->write_urb->transfer_buffer;
218 
219 	int			result;
220 
221 	if (count == 0) {
222 		dbg("%s - write request of 0 bytes", __func__);
223 		return 0;
224 	}
225 
226 	if (!test_and_clear_bit(0, &port->write_urbs_free)) {
227 		dbg("%s - already writing", __func__);
228 		return 0;
229 	}
230 
231 	count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
232 
233 	memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
234 								buf, count);
235 
236 	usb_serial_debug_data(debug, &port->dev, __func__, count,
237 					wport->write_urb->transfer_buffer);
238 
239 	header->oh_seq 	= od->od_outseq++;
240 	header->oh_len 	= count;
241 	header->oh_xxx  = 0x03;
242 	header->oh_pad 	= 0x00;
243 
244 	/* send the data out the bulk port, always 64 bytes */
245 	wport->write_urb->transfer_buffer_length = 64;
246 
247 	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
248 	if (result) {
249 		set_bit(0, &wport->write_urbs_free);
250 		dev_err_console(port,
251 			"%s - failed submitting write urb, error %d\n",
252 			__func__, result);
253 	} else
254 		result = count;
255 
256 	return result;
257 }
258 
259 
260 static int omninet_write_room(struct tty_struct *tty)
261 {
262 	struct usb_serial_port *port = tty->driver_data;
263 	struct usb_serial 	*serial = port->serial;
264 	struct usb_serial_port 	*wport 	= serial->port[1];
265 
266 	int room = 0; /* Default: no room */
267 
268 	if (test_bit(0, &wport->write_urbs_free))
269 		room = wport->bulk_out_size - OMNINET_HEADERLEN;
270 
271 	dbg("%s - returns %d", __func__, room);
272 
273 	return room;
274 }
275 
276 static void omninet_write_bulk_callback(struct urb *urb)
277 {
278 /*	struct omninet_header	*header = (struct omninet_header  *)
279 						urb->transfer_buffer; */
280 	struct usb_serial_port 	*port   =  urb->context;
281 	int status = urb->status;
282 
283 	set_bit(0, &port->write_urbs_free);
284 	if (status) {
285 		dbg("%s - nonzero write bulk status received: %d",
286 		    __func__, status);
287 		return;
288 	}
289 
290 	usb_serial_port_softint(port);
291 }
292 
293 
294 static void omninet_disconnect(struct usb_serial *serial)
295 {
296 	struct usb_serial_port *wport = serial->port[1];
297 
298 	usb_kill_urb(wport->write_urb);
299 }
300 
301 
302 static void omninet_release(struct usb_serial *serial)
303 {
304 	struct usb_serial_port *port = serial->port[0];
305 
306 	kfree(usb_get_serial_port_data(port));
307 }
308 
309 module_usb_serial_driver(omninet_driver, serial_drivers);
310 
311 MODULE_AUTHOR(DRIVER_AUTHOR);
312 MODULE_DESCRIPTION(DRIVER_DESC);
313 MODULE_LICENSE("GPL");
314 
315 module_param(debug, bool, S_IRUGO | S_IWUSR);
316 MODULE_PARM_DESC(debug, "Debug enabled or not");
317