1 /*
2 * USB Serial Console driver
3 *
4 * Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 *
10 * Thanks to Randy Dunlap for the original version of this code.
11 *
12 */
13
14 #include <linux/config.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <linux/tty.h>
19 #include <linux/console.h>
20 #include <linux/usb.h>
21
22 static int debug;
23
24 #include "usb-serial.h"
25
26 struct usbcons_info {
27 int magic;
28 int break_flag;
29 struct usb_serial_port *port;
30 };
31
32 static struct usbcons_info usbcons_info;
33 static struct console usbcons;
34
35 /*
36 * ------------------------------------------------------------
37 * USB Serial console driver
38 *
39 * Much of the code here is copied from drivers/char/serial.c
40 * and implements a phony serial console in the same way that
41 * serial.c does so that in case some software queries it,
42 * it will get the same results.
43 *
44 * Things that are different from the way the serial port code
45 * does things, is that we call the lower level usb-serial
46 * driver code to initialize the device, and we set the initial
47 * console speeds based on the command line arguments.
48 * ------------------------------------------------------------
49 */
50
51
52 /*
53 * The parsing of the command line works exactly like the
54 * serial.c code, except that the specifier is "ttyUSB" instead
55 * of "ttyS".
56 */
57 static int __init usb_console_setup(struct console *co, char *options)
58 {
59 struct usbcons_info *info = &usbcons_info;
60 int baud = 9600;
61 int bits = 8;
62 int parity = 'n';
63 int doflow = 0;
64 int cflag = CREAD | HUPCL | CLOCAL;
65 char *s;
66 struct usb_serial *serial;
67 struct usb_serial_port *port;
68 int retval = 0;
69 struct tty_struct *tty;
70 struct termios *termios;
71
72 dbg ("%s", __FUNCTION__);
73
74 if (options) {
75 baud = simple_strtoul(options, NULL, 10);
76 s = options;
77 while (*s >= '' && *s <= '9')
78 s++;
79 if (*s)
80 parity = *s++;
81 if (*s)
82 bits = *s++ - '';
83 if (*s)
84 doflow = (*s++ == 'r');
85 }
86
87 /* build a cflag setting */
88 switch (baud) {
89 case 1200:
90 cflag |= B1200;
91 break;
92 case 2400:
93 cflag |= B2400;
94 break;
95 case 4800:
96 cflag |= B4800;
97 break;
98 case 19200:
99 cflag |= B19200;
100 break;
101 case 38400:
102 cflag |= B38400;
103 break;
104 case 57600:
105 cflag |= B57600;
106 break;
107 case 115200:
108 cflag |= B115200;
109 break;
110 case 9600:
111 default:
112 cflag |= B9600;
113 /*
114 * Set this to a sane value to prevent a divide error
115 */
116 baud = 9600;
117 break;
118 }
119 switch (bits) {
120 case 7:
121 cflag |= CS7;
122 break;
123 default:
124 case 8:
125 cflag |= CS8;
126 break;
127 }
128 switch (parity) {
129 case 'o': case 'O':
130 cflag |= PARODD;
131 break;
132 case 'e': case 'E':
133 cflag |= PARENB;
134 break;
135 }
136 co->cflag = cflag;
137
138 /* grab the first serial port that happens to be connected */
139 serial = usb_serial_get_by_index(0);
140 if (serial == NULL) {
141 /* no device is connected yet, sorry :( */
142 err ("No USB device connected to ttyUSB0");
143 return -ENODEV;
144 }
145
146 port = serial->port[0];
147 port->tty = NULL;
148
149 info->port = port;
150
151 ++port->open_count;
152 if (port->open_count == 1) {
153 /* only call the device specific open if this
154 * is the first time the port is opened */
155 if (serial->type->open)
156 retval = serial->type->open(port, NULL);
157 else
158 retval = usb_serial_generic_open(port, NULL);
159 if (retval)
160 port->open_count = 0;
161 }
162
163 if (retval) {
164 err ("could not open USB console port");
165 return retval;
166 }
167
168 if (serial->type->set_termios) {
169 /* build up a fake tty structure so that the open call has something
170 * to look at to get the cflag value */
171 tty = kmalloc (sizeof (*tty), GFP_KERNEL);
172 if (!tty) {
173 err ("no more memory");
174 return -ENOMEM;
175 }
176 termios = kmalloc (sizeof (*termios), GFP_KERNEL);
177 if (!termios) {
178 err ("no more memory");
179 kfree (tty);
180 return -ENOMEM;
181 }
182 memset (tty, 0x00, sizeof(*tty));
183 memset (termios, 0x00, sizeof(*termios));
184 termios->c_cflag = cflag;
185 tty->termios = termios;
186 port->tty = tty;
187
188 /* set up the initial termios settings */
189 serial->type->set_termios(port, NULL);
190 port->tty = NULL;
191 kfree (termios);
192 kfree (tty);
193 }
194
195 return retval;
196 }
197
198 static void usb_console_write(struct console *co, const char *buf, unsigned count)
199 {
200 static struct usbcons_info *info = &usbcons_info;
201 struct usb_serial_port *port = info->port;
202 struct usb_serial *serial;
203 int retval = -ENODEV;
204
205 if (!port)
206 return;
207 serial = port->serial;
208
209 if (count == 0)
210 return;
211
212 dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
213
214 if (!port->open_count) {
215 dbg ("%s - port not opened", __FUNCTION__);
216 goto exit;
217 }
218
219 /* pass on to the driver specific version of this function if it is available */
220 if (serial->type->write)
221 retval = serial->type->write(port, buf, count);
222 else
223 retval = usb_serial_generic_write(port, buf, count);
224
225 exit:
226 dbg("%s - return value (if we had one): %d", __FUNCTION__, retval);
227 }
228
229 static struct console usbcons = {
230 .name = "ttyUSB",
231 .write = usb_console_write,
232 .setup = usb_console_setup,
233 .flags = CON_PRINTBUFFER,
234 .index = -1,
235 };
236
237 void usb_serial_console_init (int serial_debug, int minor)
238 {
239 debug = serial_debug;
240
241 if (minor == 0) {
242 /*
243 * Call register_console() if this is the first device plugged
244 * in. If we call it earlier, then the callback to
245 * console_setup() will fail, as there is not a device seen by
246 * the USB subsystem yet.
247 */
248 /*
249 * Register console.
250 * NOTES:
251 * console_setup() is called (back) immediately (from register_console).
252 * console_write() is called immediately from register_console iff
253 * CON_PRINTBUFFER is set in flags.
254 */
255 dbg ("registering the USB serial console.");
256 register_console(&usbcons);
257 }
258 }
259
260 void usb_serial_console_exit (void)
261 {
262 unregister_console(&usbcons);
263 }
264
265
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