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 tty_port_tty_set(&port->port, 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 kref_init(&tty->kref); 139 termios = kzalloc(sizeof(*termios), GFP_KERNEL); 140 if (!termios) { 141 retval = -ENOMEM; 142 err("no more memory"); 143 goto free_tty; 144 } 145 memset(&dummy, 0, sizeof(struct ktermios)); 146 tty->termios = termios; 147 tty_port_tty_set(&port->port, tty); 148 } 149 150 /* only call the device specific open if this 151 * is the first time the port is opened */ 152 if (serial->type->open) 153 retval = serial->type->open(NULL, port, NULL); 154 else 155 retval = usb_serial_generic_open(NULL, port, NULL); 156 157 if (retval) { 158 err("could not open USB console port"); 159 goto free_termios; 160 } 161 162 if (serial->type->set_termios) { 163 termios->c_cflag = cflag; 164 tty_termios_encode_baud_rate(termios, baud, baud); 165 serial->type->set_termios(tty, port, &dummy); 166 167 tty_port_tty_set(&port->port, NULL); 168 kfree(termios); 169 kfree(tty); 170 } 171 } 172 173 port->console = 1; 174 retval = 0; 175 176 out: 177 return retval; 178 free_termios: 179 kfree(termios); 180 tty_port_tty_set(&port->port, NULL); 181 free_tty: 182 kfree(tty); 183 reset_open_count: 184 port->port.count = 0; 185 goto out; 186 } 187 188 static void usb_console_write(struct console *co, 189 const char *buf, unsigned count) 190 { 191 static struct usbcons_info *info = &usbcons_info; 192 struct usb_serial_port *port = info->port; 193 struct usb_serial *serial; 194 int retval = -ENODEV; 195 196 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED) 197 return; 198 serial = port->serial; 199 200 if (count == 0) 201 return; 202 203 dbg("%s - port %d, %d byte(s)", __func__, port->number, count); 204 205 if (!port->port.count) { 206 dbg("%s - port not opened", __func__); 207 return; 208 } 209 210 while (count) { 211 unsigned int i; 212 unsigned int lf; 213 /* search for LF so we can insert CR if necessary */ 214 for (i = 0, lf = 0 ; i < count ; i++) { 215 if (*(buf + i) == 10) { 216 lf = 1; 217 i++; 218 break; 219 } 220 } 221 /* pass on to the driver specific version of this function if 222 it is available */ 223 if (serial->type->write) 224 retval = serial->type->write(NULL, port, buf, i); 225 else 226 retval = usb_serial_generic_write(NULL, port, buf, i); 227 dbg("%s - return value : %d", __func__, retval); 228 if (lf) { 229 /* append CR after LF */ 230 unsigned char cr = 13; 231 if (serial->type->write) 232 retval = serial->type->write(NULL, 233 port, &cr, 1); 234 else 235 retval = usb_serial_generic_write(NULL, 236 port, &cr, 1); 237 dbg("%s - return value : %d", __func__, retval); 238 } 239 buf += i; 240 count -= i; 241 } 242 } 243 244 static struct console usbcons = { 245 .name = "ttyUSB", 246 .write = usb_console_write, 247 .setup = usb_console_setup, 248 .flags = CON_PRINTBUFFER, 249 .index = -1, 250 }; 251 252 void usb_serial_console_disconnect(struct usb_serial *serial) 253 { 254 if (serial && serial->port && serial->port[0] 255 && serial->port[0] == usbcons_info.port) { 256 usb_serial_console_exit(); 257 usb_serial_put(serial); 258 } 259 } 260 261 void usb_serial_console_init(int serial_debug, int minor) 262 { 263 debug = serial_debug; 264 265 if (minor == 0) { 266 /* 267 * Call register_console() if this is the first device plugged 268 * in. If we call it earlier, then the callback to 269 * console_setup() will fail, as there is not a device seen by 270 * the USB subsystem yet. 271 */ 272 /* 273 * Register console. 274 * NOTES: 275 * console_setup() is called (back) immediately (from 276 * register_console). console_write() is called immediately 277 * from register_console iff CON_PRINTBUFFER is set in flags. 278 */ 279 dbg("registering the USB serial console."); 280 register_console(&usbcons); 281 } 282 } 283 284 void usb_serial_console_exit(void) 285 { 286 if (usbcons_info.port) { 287 unregister_console(&usbcons); 288 if (usbcons_info.port->port.count) 289 usbcons_info.port->port.count--; 290 usbcons_info.port = NULL; 291 } 292 } 293 294