Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[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         /* Sane default */
86         if (baud == 0)
87                 baud = 9600;
88
89         switch (bits) {
90         case 7:
91                 cflag |= CS7;
92                 break;
93         default:
94         case 8:
95                 cflag |= CS8;
96                 break;
97         }
98         switch (parity) {
99         case 'o': case 'O':
100                 cflag |= PARODD;
101                 break;
102         case 'e': case 'E':
103                 cflag |= PARENB;
104                 break;
105         }
106         co->cflag = cflag;
107
108         /*
109          * no need to check the index here: if the index is wrong, console
110          * code won't call us
111          */
112         serial = usb_serial_get_by_index(co->index);
113         if (serial == NULL) {
114                 /* no device is connected yet, sorry :( */
115                 err("No USB device connected to ttyUSB%i", co->index);
116                 return -ENODEV;
117         }
118
119         port = serial->port[0];
120         port->port.tty = NULL;
121
122         info->port = port;
123
124         ++port->port.count;
125         if (port->port.count == 1) {
126                 if (serial->type->set_termios) {
127                         /*
128                          * allocate a fake tty so the driver can initialize
129                          * the termios structure, then later call set_termios to
130                          * configure according to command line arguments
131                          */
132                         tty = kzalloc(sizeof(*tty), GFP_KERNEL);
133                         if (!tty) {
134                                 retval = -ENOMEM;
135                                 err("no more memory");
136                                 goto reset_open_count;
137                         }
138                         termios = kzalloc(sizeof(*termios), GFP_KERNEL);
139                         if (!termios) {
140                                 retval = -ENOMEM;
141                                 err("no more memory");
142                                 goto free_tty;
143                         }
144                         memset(&dummy, 0, sizeof(struct ktermios));
145                         tty->termios = termios;
146                         port->port.tty = tty;
147                 }
148
149                 /* only call the device specific open if this
150                  * is the first time the port is opened */
151                 if (serial->type->open)
152                         retval = serial->type->open(NULL, port, NULL);
153                 else
154                         retval = usb_serial_generic_open(NULL, port, NULL);
155
156                 if (retval) {
157                         err("could not open USB console port");
158                         goto free_termios;
159                 }
160
161                 if (serial->type->set_termios) {
162                         termios->c_cflag = cflag;
163                         tty_termios_encode_baud_rate(termios, baud, baud);
164                         serial->type->set_termios(tty, port, &dummy);
165
166                         port->port.tty = NULL;
167                         kfree(termios);
168                         kfree(tty);
169                 }
170         }
171
172         port->console = 1;
173         retval = 0;
174
175 out:
176         return retval;
177 free_termios:
178         kfree(termios);
179         port->port.tty = NULL;
180 free_tty:
181         kfree(tty);
182 reset_open_count:
183         port->port.count = 0;
184 goto out;
185 }
186
187 static void usb_console_write(struct console *co,
188                                         const char *buf, unsigned count)
189 {
190         static struct usbcons_info *info = &usbcons_info;
191         struct usb_serial_port *port = info->port;
192         struct usb_serial *serial;
193         int retval = -ENODEV;
194
195         if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
196                 return;
197         serial = port->serial;
198
199         if (count == 0)
200                 return;
201
202         dbg("%s - port %d, %d byte(s)", __func__, port->number, count);
203
204         if (!port->port.count) {
205                 dbg("%s - port not opened", __func__);
206                 return;
207         }
208
209         while (count) {
210                 unsigned int i;
211                 unsigned int lf;
212                 /* search for LF so we can insert CR if necessary */
213                 for (i = 0, lf = 0 ; i < count ; i++) {
214                         if (*(buf + i) == 10) {
215                                 lf = 1;
216                                 i++;
217                                 break;
218                         }
219                 }
220                 /* pass on to the driver specific version of this function if
221                    it is available */
222                 if (serial->type->write)
223                         retval = serial->type->write(NULL, port, buf, i);
224                 else
225                         retval = usb_serial_generic_write(NULL, port, buf, i);
226                 dbg("%s - return value : %d", __func__, retval);
227                 if (lf) {
228                         /* append CR after LF */
229                         unsigned char cr = 13;
230                         if (serial->type->write)
231                                 retval = serial->type->write(NULL,
232                                                                 port, &cr, 1);
233                         else
234                                 retval = usb_serial_generic_write(NULL,
235                                                                 port, &cr, 1);
236                         dbg("%s - return value : %d", __func__, retval);
237                 }
238                 buf += i;
239                 count -= i;
240         }
241 }
242
243 static struct console usbcons = {
244         .name =         "ttyUSB",
245         .write =        usb_console_write,
246         .setup =        usb_console_setup,
247         .flags =        CON_PRINTBUFFER,
248         .index =        -1,
249 };
250
251 void usb_serial_console_disconnect(struct usb_serial *serial)
252 {
253         if (serial && serial->port && serial->port[0]
254                                 && serial->port[0] == usbcons_info.port) {
255                 usb_serial_console_exit();
256                 usb_serial_put(serial);
257         }
258 }
259
260 void usb_serial_console_init(int serial_debug, int minor)
261 {
262         debug = serial_debug;
263
264         if (minor == 0) {
265                 /*
266                  * Call register_console() if this is the first device plugged
267                  * in.  If we call it earlier, then the callback to
268                  * console_setup() will fail, as there is not a device seen by
269                  * the USB subsystem yet.
270                  */
271                 /*
272                  * Register console.
273                  * NOTES:
274                  * console_setup() is called (back) immediately (from
275                  * register_console). console_write() is called immediately
276                  * from register_console iff CON_PRINTBUFFER is set in flags.
277                  */
278                 dbg("registering the USB serial console.");
279                 register_console(&usbcons);
280         }
281 }
282
283 void usb_serial_console_exit(void)
284 {
285         if (usbcons_info.port) {
286                 unregister_console(&usbcons);
287                 if (usbcons_info.port->port.count)
288                         usbcons_info.port->port.count--;
289                 usbcons_info.port = NULL;
290         }
291 }
292