Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6] / drivers / usb / serial / console.c
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/kernel.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/console.h>
19 #include <linux/usb.h>
20 #include <linux/usb/serial.h>
21
22 static int debug;
23
24 struct usbcons_info {
25         int                     magic;
26         int                     break_flag;
27         struct usb_serial_port  *port;
28 };
29
30 static struct usbcons_info usbcons_info;
31 static struct console usbcons;
32
33 /*
34  * ------------------------------------------------------------
35  * USB Serial console driver
36  *
37  * Much of the code here is copied from drivers/char/serial.c
38  * and implements a phony serial console in the same way that
39  * serial.c does so that in case some software queries it,
40  * it will get the same results.
41  *
42  * Things that are different from the way the serial port code
43  * does things, is that we call the lower level usb-serial
44  * driver code to initialize the device, and we set the initial
45  * console speeds based on the command line arguments.
46  * ------------------------------------------------------------
47  */
48
49
50 /*
51  * The parsing of the command line works exactly like the
52  * serial.c code, except that the specifier is "ttyUSB" instead
53  * of "ttyS".
54  */
55 static int usb_console_setup(struct console *co, char *options)
56 {
57         struct usbcons_info *info = &usbcons_info;
58         int baud = 9600;
59         int bits = 8;
60         int parity = 'n';
61         int doflow = 0;
62         int cflag = CREAD | HUPCL | CLOCAL;
63         char *s;
64         struct usb_serial *serial;
65         struct usb_serial_port *port;
66         int retval = 0;
67         struct tty_struct *tty = NULL;
68         struct ktermios *termios = NULL, dummy;
69
70         dbg ("%s", __func__);
71
72         if (options) {
73                 baud = simple_strtoul(options, NULL, 10);
74                 s = options;
75                 while (*s >= '0' && *s <= '9')
76                         s++;
77                 if (*s)
78                         parity = *s++;
79                 if (*s)
80                         bits   = *s++ - '0';
81                 if (*s)
82                         doflow = (*s++ == 'r');
83         }
84
85         /* build a cflag setting */
86         switch (baud) {
87                 case 1200:
88                         cflag |= B1200;
89                         break;
90                 case 2400:
91                         cflag |= B2400;
92                         break;
93                 case 4800:
94                         cflag |= B4800;
95                         break;
96                 case 19200:
97                         cflag |= B19200;
98                         break;
99                 case 38400:
100                         cflag |= B38400;
101                         break;
102                 case 57600:
103                         cflag |= B57600;
104                         break;
105                 case 115200:
106                         cflag |= B115200;
107                         break;
108                 case 9600:
109                 default:
110                         cflag |= B9600;
111                         /*
112                          * Set this to a sane value to prevent a divide error
113                          */
114                         baud  = 9600;
115                         break;
116         }
117         switch (bits) {
118                 case 7:
119                         cflag |= CS7;
120                         break;
121                 default:
122                 case 8:
123                         cflag |= CS8;
124                         break;
125         }
126         switch (parity) {
127                 case 'o': case 'O':
128                         cflag |= PARODD;
129                         break;
130                 case 'e': case 'E':
131                         cflag |= PARENB;
132                         break;
133         }
134         co->cflag = cflag;
135
136         /*
137          * no need to check the index here: if the index is wrong, console
138          * code won't call us
139          */
140         serial = usb_serial_get_by_index(co->index);
141         if (serial == NULL) {
142                 /* no device is connected yet, sorry :( */
143                 err ("No USB device connected to ttyUSB%i", co->index);
144                 return -ENODEV;
145         }
146
147         port = serial->port[0];
148         port->tty = NULL;
149
150         info->port = port;
151          
152         ++port->open_count;
153         if (port->open_count == 1) {
154                 if (serial->type->set_termios) {
155                         /*
156                          * allocate a fake tty so the driver can initialize
157                          * the termios structure, then later call set_termios to
158                          * configure according to command line arguments
159                          */
160                         tty = kzalloc(sizeof(*tty), GFP_KERNEL);
161                         if (!tty) {
162                                 retval = -ENOMEM;
163                                 err("no more memory");
164                                 goto reset_open_count;
165                         }
166                         termios = kzalloc(sizeof(*termios), GFP_KERNEL);
167                         if (!termios) {
168                                 retval = -ENOMEM;
169                                 err("no more memory");
170                                 goto free_tty;
171                         }
172                         memset(&dummy, 0, sizeof(struct ktermios));
173                         tty->termios = termios;
174                         port->tty = tty;
175                 }
176
177                 /* only call the device specific open if this 
178                  * is the first time the port is opened */
179                 if (serial->type->open)
180                         retval = serial->type->open(port, NULL);
181                 else
182                         retval = usb_serial_generic_open(port, NULL);
183
184                 if (retval) {
185                         err("could not open USB console port");
186                         goto free_termios;
187                 }
188
189                 if (serial->type->set_termios) {
190                         termios->c_cflag = cflag;
191                         serial->type->set_termios(port, &dummy);
192
193                         port->tty = NULL;
194                         kfree(termios);
195                         kfree(tty);
196                 }
197         }
198
199         port->console = 1;
200         retval = 0;
201
202 out:
203         return retval;
204 free_termios:
205         kfree(termios);
206         port->tty = NULL;
207 free_tty:
208         kfree(tty);
209 reset_open_count:
210         port->open_count = 0;
211 goto out;
212 }
213
214 static void usb_console_write(struct console *co, const char *buf, unsigned count)
215 {
216         static struct usbcons_info *info = &usbcons_info;
217         struct usb_serial_port *port = info->port;
218         struct usb_serial *serial;
219         int retval = -ENODEV;
220
221         if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
222                 return;
223         serial = port->serial;
224
225         if (count == 0)
226                 return;
227
228         dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
229
230         if (!port->open_count) {
231                 dbg ("%s - port not opened", __func__);
232                 return;
233         }
234
235         while (count) {
236                 unsigned int i;
237                 unsigned int lf;
238                 /* search for LF so we can insert CR if necessary */
239                 for (i=0, lf=0 ; i < count ; i++) {
240                         if (*(buf + i) == 10) {
241                                 lf = 1;
242                                 i++;
243                                 break;
244                         }
245                 }
246                 /* pass on to the driver specific version of this function if it is available */
247                 if (serial->type->write)
248                         retval = serial->type->write(port, buf, i);
249                 else
250                         retval = usb_serial_generic_write(port, buf, i);
251                 dbg("%s - return value : %d", __func__, retval);
252                 if (lf) {
253                         /* append CR after LF */
254                         unsigned char cr = 13;
255                         if (serial->type->write)
256                                 retval = serial->type->write(port, &cr, 1);
257                         else
258                                 retval = usb_serial_generic_write(port, &cr, 1);
259                         dbg("%s - return value : %d", __func__, retval);
260                 }
261                 buf += i;
262                 count -= i;
263         }
264 }
265
266 static struct console usbcons = {
267         .name =         "ttyUSB",
268         .write =        usb_console_write,
269         .setup =        usb_console_setup,
270         .flags =        CON_PRINTBUFFER,
271         .index =        -1,
272 };
273
274 void usb_serial_console_disconnect(struct usb_serial *serial)
275 {
276         if (serial && serial->port && serial->port[0] && serial->port[0] == usbcons_info.port) {
277                 usb_serial_console_exit();
278                 usb_serial_put(serial);
279         }
280 }
281
282 void usb_serial_console_init (int serial_debug, int minor)
283 {
284         debug = serial_debug;
285
286         if (minor == 0) {
287                 /* 
288                  * Call register_console() if this is the first device plugged
289                  * in.  If we call it earlier, then the callback to
290                  * console_setup() will fail, as there is not a device seen by
291                  * the USB subsystem yet.
292                  */
293                 /*
294                  * Register console.
295                  * NOTES:
296                  * console_setup() is called (back) immediately (from register_console).
297                  * console_write() is called immediately from register_console iff
298                  * CON_PRINTBUFFER is set in flags.
299                  */
300                 dbg ("registering the USB serial console.");
301                 register_console(&usbcons);
302         }
303 }
304
305 void usb_serial_console_exit (void)
306 {
307         if (usbcons_info.port) {
308                 unregister_console(&usbcons);
309                 if (usbcons_info.port->open_count)
310                         usbcons_info.port->open_count--;
311                 usbcons_info.port = NULL;
312         }
313 }
314