Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 >= '0' && *s <= '9') |
| 78 | s++; |
| 79 | if (*s) |
| 80 | parity = *s++; |
| 81 | if (*s) |
| 82 | bits = *s++ - '0'; |
| 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 | |