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
  21 static int debug;
  22
  23 #include "usb-serial.h"
  24
  25 struct usbcons_info {
  26         int                     magic;
  27         int                     break_flag;
  28         struct usb_serial_port  *port;
  29 };
  30
  31 static struct usbcons_info usbcons_info;
  32 static struct console usbcons;
  33
  34 /*
  35  * ------------------------------------------------------------
  36  * USB Serial console driver
  37  *
  38  * Much of the code here is copied from drivers/char/serial.c
  39  * and implements a phony serial console in the same way that
  40  * serial.c does so that in case some software queries it,
  41  * it will get the same results.
  42  *
  43  * Things that are different from the way the serial port code
  44  * does things, is that we call the lower level usb-serial
  45  * driver code to initialize the device, and we set the initial
  46  * console speeds based on the command line arguments.
  47  * ------------------------------------------------------------
  48  */
  49
  50
  51 /*
  52  * The parsing of the command line works exactly like the
  53  * serial.c code, except that the specifier is "ttyUSB" instead
  54  * of "ttyS".
  55  */
  56 static int usb_console_setup(struct console *co, char *options)
  57 {
  58         struct usbcons_info *info = &usbcons_info;
  59         int baud = 9600;
  60         int bits = 8;
  61         int parity = 'n';
  62         int doflow = 0;
  63         int cflag = CREAD | HUPCL | CLOCAL;
  64         char *s;
  65         struct usb_serial *serial;
  66         struct usb_serial_port *port;
  67         int retval = 0;
  68         struct tty_struct *tty;
  69         struct termios *termios;
  70
  71         dbg ("%s", __FUNCTION__);
  72
  73         if (options) {
  74                 baud = simple_strtoul(options, NULL, 10);
  75                 s = options;
  76                 while (*s >= '0' && *s <= '9')
  77                         s++;
  78                 if (*s)
  79                         parity = *s++;
  80                 if (*s)
  81                         bits   = *s++ - '0';
  82                 if (*s)
  83                         doflow = (*s++ == 'r');
  84         }
  85
  86         /* build a cflag setting */
  87         switch (baud) {
  88                 case 1200:
  89                         cflag |= B1200;
  90                         break;
  91                 case 2400:
  92                         cflag |= B2400;
  93                         break;
  94                 case 4800:
  95                         cflag |= B4800;
  96                         break;
  97                 case 19200:
  98                         cflag |= B19200;
  99                         break;
 100                 case 38400:
 101                         cflag |= B38400;
 102                         break;
 103                 case 57600:
 104                         cflag |= B57600;
 105                         break;
 106                 case 115200:
 107                         cflag |= B115200;
 108                         break;
 109                 case 9600:
 110                 default:
 111                         cflag |= B9600;
 112                         /*
 113                          * Set this to a sane value to prevent a divide error
 114                          */
 115                         baud  = 9600;
 116                         break;
 117         }
 118         switch (bits) {
 119                 case 7:
 120                         cflag |= CS7;
 121                         break;
 122                 default:
 123                 case 8:
 124                         cflag |= CS8;
 125                         break;
 126         }
 127         switch (parity) {
 128                 case 'o': case 'O':
 129                         cflag |= PARODD;
 130                         break;
 131                 case 'e': case 'E':
 132                         cflag |= PARENB;
 133                         break;
 134         }
 135         co->cflag = cflag;
 136
 137         /* grab the first serial port that happens to be connected */
 138         serial = usb_serial_get_by_index(0);
 139         if (serial == NULL) {
 140                 /* no device is connected yet, sorry :( */
 141                 err ("No USB device connected to ttyUSB0");
 142                 return -ENODEV;
 143         }
 144
 145         port = serial->port[0];
 146         port->tty = NULL;
 147
 148         info->port = port;
 149
 150         ++port->open_count;
 151         if (port->open_count == 1) {
 152                 /* only call the device specific open if this
 153                  * is the first time the port is opened */
 154                 if (serial->type->open)
 155                         retval = serial->type->open(port, NULL);
 156                 else
 157                         retval = usb_serial_generic_open(port, NULL);
 158                 if (retval)
 159                         port->open_count = 0;
 160         }
 161
 162         if (retval) {
 163                 err ("could not open USB console port");
 164                 return retval;
 165         }
 166
 167         if (serial->type->set_termios) {
 168                 /* build up a fake tty structure so that the open call has something
 169                  * to look at to get the cflag value */
 170                 tty = kmalloc (sizeof (*tty), GFP_KERNEL);
 171                 if (!tty) {
 172                         err ("no more memory");
 173                         return -ENOMEM;
 174                 }
 175                 termios = kmalloc (sizeof (*termios), GFP_KERNEL);
 176                 if (!termios) {
 177                         err ("no more memory");
 178                         kfree (tty);
 179                         return -ENOMEM;
 180                 }
 181                 memset (tty, 0x00, sizeof(*tty));
 182                 memset (termios, 0x00, sizeof(*termios));
 183                 termios->c_cflag = cflag;
 184                 tty->termios = termios;
 185                 port->tty = tty;
 186
 187                 /* set up the initial termios settings */
 188                 serial->type->set_termios(port, NULL);
 189                 port->tty = NULL;
 190                 kfree (termios);
 191                 kfree (tty);
 192         }
 193
 194         return retval;
 195 }
 196
 197 static void usb_console_write(struct console *co, const char *buf, unsigned count)
 198 {
 199         static struct usbcons_info *info = &usbcons_info;
 200         struct usb_serial_port *port = info->port;
 201         struct usb_serial *serial;
 202         int retval = -ENODEV;
 203
 204         if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
 205                 return;
 206         serial = port->serial;
 207
 208         if (count == 0)
 209                 return;
 210
 211         dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
 212
 213         if (!port->open_count) {
 214                 dbg ("%s - port not opened", __FUNCTION__);
 215                 return;
 216         }
 217
 218         while (count) {
 219                 unsigned int i;
 220                 unsigned int lf;
 221                 /* search for LF so we can insert CR if necessary */
 222                 for (i=0, lf=0 ; i < count ; i++) {
 223                         if (*(buf + i) == 10) {
 224                                 lf = 1;
 225                                 i++;
 226                                 break;
 227                         }
 228                 }
 229                 /* pass on to the driver specific version of this function if it is available */
 230                 if (serial->type->write)
 231                         retval = serial->type->write(port, buf, i);
 232                 else
 233                         retval = usb_serial_generic_write(port, buf, i);
 234                 dbg("%s - return value : %d", __FUNCTION__, retval);
 235                 if (lf) {
 236                         /* append CR after LF */
 237                         unsigned char cr = 13;
 238                         if (serial->type->write)
 239                                 retval = serial->type->write(port, &cr, 1);
 240                         else
 241                                 retval = usb_serial_generic_write(port, &cr, 1);
 242                         dbg("%s - return value : %d", __FUNCTION__, retval);
 243                 }
 244                 buf += i;
 245                 count -= i;
 246         }
 247 }
 248
 249 static struct console usbcons = {
 250         .name =         "ttyUSB",
 251         .write =        usb_console_write,
 252         .setup =        usb_console_setup,
 253         .flags =        CON_PRINTBUFFER,
 254         .index =        -1,
 255 };
 256
 257 void usb_serial_console_disconnect(struct usb_serial *serial)
 258 {
 259         if (serial && serial->port && serial->port[0] && serial->port[0] == usbcons_info.port) {
 260                 usb_serial_console_exit();
 261                 usb_serial_put(serial);
 262         }
 263 }
 264
 265 void usb_serial_console_init (int serial_debug, int minor)
 266 {
 267         debug = serial_debug;
 268
 269         if (minor == 0) {
 270                 /*
 271                  * Call register_console() if this is the first device plugged
 272                  * in.  If we call it earlier, then the callback to
 273                  * console_setup() will fail, as there is not a device seen by
 274                  * the USB subsystem yet.
 275                  */
 276                 /*
 277                  * Register console.
 278                  * NOTES:
 279                  * console_setup() is called (back) immediately (from register_console).
 280                  * console_write() is called immediately from register_console iff
 281                  * CON_PRINTBUFFER is set in flags.
 282                  */
 283                 dbg ("registering the USB serial console.");
 284                 register_console(&usbcons);
 285         }
 286 }
 287
 288 void usb_serial_console_exit (void)
 289 {
 290         if (usbcons_info.port) {
 291                 unregister_console(&usbcons);
 292                 if (usbcons_info.port->open_count)
 293                         usbcons_info.port->open_count--;
 294                 usbcons_info.port = NULL;
 295         }
 296 }
 297