xref: /openbmc/linux/drivers/usb/serial/omninet.c (revision 95e9fd10)
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 MODULE_DEVICE_TABLE(usb, id_table);
58 
59 static struct usb_serial_driver zyxel_omninet_device = {
60 	.driver = {
61 		.owner =	THIS_MODULE,
62 		.name =		"omninet",
63 	},
64 	.description =		"ZyXEL - omni.net lcd plus usb",
65 	.id_table =		id_table,
66 	.num_ports =		1,
67 	.attach =		omninet_attach,
68 	.open =			omninet_open,
69 	.close =		omninet_close,
70 	.write =		omninet_write,
71 	.write_room =		omninet_write_room,
72 	.read_bulk_callback =	omninet_read_bulk_callback,
73 	.write_bulk_callback =	omninet_write_bulk_callback,
74 	.disconnect =		omninet_disconnect,
75 	.release =		omninet_release,
76 };
77 
78 static struct usb_serial_driver * const serial_drivers[] = {
79 	&zyxel_omninet_device, NULL
80 };
81 
82 
83 /* The protocol.
84  *
85  * The omni.net always exchange 64 bytes of data with the host. The first
86  * four bytes are the control header, you can see it in the above structure.
87  *
88  * oh_seq is a sequence number. Don't know if/how it's used.
89  * oh_len is the length of the data bytes in the packet.
90  * oh_xxx Bit-mapped, related to handshaking and status info.
91  *	I normally set it to 0x03 in trasmitted frames.
92  *	7: Active when the TA is in a CONNECTed state.
93  *	6: unknown
94  *	5: handshaking, unknown
95  *	4: handshaking, unknown
96  *	3: unknown, usually 0
97  *	2: unknown, usually 0
98  *	1: handshaking, unknown, usually set to 1 in trasmitted frames
99  *	0: handshaking, unknown, usually set to 1 in trasmitted frames
100  * oh_pad Probably a pad byte.
101  *
102  * After the header you will find data bytes if oh_len was greater than zero.
103  *
104  */
105 
106 struct omninet_header {
107 	__u8	oh_seq;
108 	__u8	oh_len;
109 	__u8	oh_xxx;
110 	__u8	oh_pad;
111 };
112 
113 struct omninet_data {
114 	__u8	od_outseq;	/* Sequence number for bulk_out URBs */
115 };
116 
117 static int omninet_attach(struct usb_serial *serial)
118 {
119 	struct omninet_data *od;
120 	struct usb_serial_port *port = serial->port[0];
121 
122 	od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
123 	if (!od) {
124 		dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n",
125 			__func__, sizeof(struct omninet_data));
126 		return -ENOMEM;
127 	}
128 	usb_set_serial_port_data(port, od);
129 	return 0;
130 }
131 
132 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
133 {
134 	struct usb_serial	*serial = port->serial;
135 	struct usb_serial_port	*wport;
136 	int			result = 0;
137 
138 	wport = serial->port[1];
139 	tty_port_tty_set(&wport->port, tty);
140 
141 	/* Start reading from the device */
142 	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
143 	if (result)
144 		dev_err(&port->dev,
145 			"%s - failed submitting read urb, error %d\n",
146 			__func__, result);
147 	return result;
148 }
149 
150 static void omninet_close(struct usb_serial_port *port)
151 {
152 	usb_kill_urb(port->read_urb);
153 }
154 
155 
156 #define OMNINET_DATAOFFSET	0x04
157 #define OMNINET_HEADERLEN	sizeof(struct omninet_header)
158 #define OMNINET_BULKOUTSIZE 	(64 - OMNINET_HEADERLEN)
159 
160 static void omninet_read_bulk_callback(struct urb *urb)
161 {
162 	struct usb_serial_port 	*port 	= urb->context;
163 	unsigned char 		*data 	= urb->transfer_buffer;
164 	struct omninet_header 	*header = (struct omninet_header *) &data[0];
165 	int status = urb->status;
166 	int result;
167 	int i;
168 
169 	if (status) {
170 		dbg("%s - nonzero read bulk status received: %d",
171 		    __func__, status);
172 		return;
173 	}
174 
175 	if (debug && header->oh_xxx != 0x30) {
176 		if (urb->actual_length) {
177 			printk(KERN_DEBUG "%s: omninet_read %d: ",
178 			       __FILE__, header->oh_len);
179 			for (i = 0; i < (header->oh_len +
180 						OMNINET_HEADERLEN); i++)
181 				printk("%.2x ", data[i]);
182 			printk("\n");
183 		}
184 	}
185 
186 	if (urb->actual_length && header->oh_len) {
187 		struct tty_struct *tty = tty_port_tty_get(&port->port);
188 		tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
189 							header->oh_len);
190 		tty_flip_buffer_push(tty);
191 		tty_kref_put(tty);
192 	}
193 
194 	/* Continue trying to always read  */
195 	result = usb_submit_urb(urb, GFP_ATOMIC);
196 	if (result)
197 		dev_err(&port->dev,
198 			"%s - failed resubmitting read urb, error %d\n",
199 			__func__, result);
200 }
201 
202 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
203 					const unsigned char *buf, int count)
204 {
205 	struct usb_serial *serial = port->serial;
206 	struct usb_serial_port *wport = serial->port[1];
207 
208 	struct omninet_data *od = usb_get_serial_port_data(port);
209 	struct omninet_header *header = (struct omninet_header *)
210 					wport->write_urb->transfer_buffer;
211 
212 	int			result;
213 
214 	if (count == 0) {
215 		dbg("%s - write request of 0 bytes", __func__);
216 		return 0;
217 	}
218 
219 	if (!test_and_clear_bit(0, &port->write_urbs_free)) {
220 		dbg("%s - already writing", __func__);
221 		return 0;
222 	}
223 
224 	count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
225 
226 	memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
227 								buf, count);
228 
229 	usb_serial_debug_data(debug, &port->dev, __func__, count,
230 					wport->write_urb->transfer_buffer);
231 
232 	header->oh_seq 	= od->od_outseq++;
233 	header->oh_len 	= count;
234 	header->oh_xxx  = 0x03;
235 	header->oh_pad 	= 0x00;
236 
237 	/* send the data out the bulk port, always 64 bytes */
238 	wport->write_urb->transfer_buffer_length = 64;
239 
240 	result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
241 	if (result) {
242 		set_bit(0, &wport->write_urbs_free);
243 		dev_err_console(port,
244 			"%s - failed submitting write urb, error %d\n",
245 			__func__, result);
246 	} else
247 		result = count;
248 
249 	return result;
250 }
251 
252 
253 static int omninet_write_room(struct tty_struct *tty)
254 {
255 	struct usb_serial_port *port = tty->driver_data;
256 	struct usb_serial 	*serial = port->serial;
257 	struct usb_serial_port 	*wport 	= serial->port[1];
258 
259 	int room = 0; /* Default: no room */
260 
261 	if (test_bit(0, &wport->write_urbs_free))
262 		room = wport->bulk_out_size - OMNINET_HEADERLEN;
263 
264 	dbg("%s - returns %d", __func__, room);
265 
266 	return room;
267 }
268 
269 static void omninet_write_bulk_callback(struct urb *urb)
270 {
271 /*	struct omninet_header	*header = (struct omninet_header  *)
272 						urb->transfer_buffer; */
273 	struct usb_serial_port 	*port   =  urb->context;
274 	int status = urb->status;
275 
276 	set_bit(0, &port->write_urbs_free);
277 	if (status) {
278 		dbg("%s - nonzero write bulk status received: %d",
279 		    __func__, status);
280 		return;
281 	}
282 
283 	usb_serial_port_softint(port);
284 }
285 
286 
287 static void omninet_disconnect(struct usb_serial *serial)
288 {
289 	struct usb_serial_port *wport = serial->port[1];
290 
291 	usb_kill_urb(wport->write_urb);
292 }
293 
294 
295 static void omninet_release(struct usb_serial *serial)
296 {
297 	struct usb_serial_port *port = serial->port[0];
298 
299 	kfree(usb_get_serial_port_data(port));
300 }
301 
302 module_usb_serial_driver(serial_drivers, id_table);
303 
304 MODULE_AUTHOR(DRIVER_AUTHOR);
305 MODULE_DESCRIPTION(DRIVER_DESC);
306 MODULE_LICENSE("GPL");
307 
308 module_param(debug, bool, S_IRUGO | S_IWUSR);
309 MODULE_PARM_DESC(debug, "Debug enabled or not");
310