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(NULL, 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 } 292 293