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/serial.h> 20 #include <linux/usb.h> 21 #include <linux/usb/serial.h> 22 23 static int debug; 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; 68 struct tty_struct *tty = NULL; 69 struct ktermios *termios = NULL, dummy; 70 71 dbg("%s", __func__); 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 /* Sane default */ 87 if (baud == 0) 88 baud = 9600; 89 90 switch (bits) { 91 case 7: 92 cflag |= CS7; 93 break; 94 default: 95 case 8: 96 cflag |= CS8; 97 break; 98 } 99 switch (parity) { 100 case 'o': case 'O': 101 cflag |= PARODD; 102 break; 103 case 'e': case 'E': 104 cflag |= PARENB; 105 break; 106 } 107 co->cflag = cflag; 108 109 /* 110 * no need to check the index here: if the index is wrong, console 111 * code won't call us 112 */ 113 serial = usb_serial_get_by_index(co->index); 114 if (serial == NULL) { 115 /* no device is connected yet, sorry :( */ 116 err("No USB device connected to ttyUSB%i", co->index); 117 return -ENODEV; 118 } 119 120 retval = usb_autopm_get_interface(serial->interface); 121 if (retval) 122 goto error_get_interface; 123 124 port = serial->port[co->index - serial->minor]; 125 tty_port_tty_set(&port->port, NULL); 126 127 info->port = port; 128 129 ++port->port.count; 130 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) { 131 if (serial->type->set_termios) { 132 /* 133 * allocate a fake tty so the driver can initialize 134 * the termios structure, then later call set_termios to 135 * configure according to command line arguments 136 */ 137 tty = kzalloc(sizeof(*tty), GFP_KERNEL); 138 if (!tty) { 139 retval = -ENOMEM; 140 err("no more memory"); 141 goto reset_open_count; 142 } 143 kref_init(&tty->kref); 144 termios = kzalloc(sizeof(*termios), GFP_KERNEL); 145 if (!termios) { 146 retval = -ENOMEM; 147 err("no more memory"); 148 goto free_tty; 149 } 150 memset(&dummy, 0, sizeof(struct ktermios)); 151 tty->termios = termios; 152 tty_port_tty_set(&port->port, tty); 153 } 154 155 /* only call the device specific open if this 156 * is the first time the port is opened */ 157 if (serial->type->open) 158 retval = serial->type->open(NULL, port); 159 else 160 retval = usb_serial_generic_open(NULL, port); 161 162 if (retval) { 163 err("could not open USB console port"); 164 goto free_termios; 165 } 166 167 if (serial->type->set_termios) { 168 termios->c_cflag = cflag; 169 tty_termios_encode_baud_rate(termios, baud, baud); 170 serial->type->set_termios(tty, port, &dummy); 171 172 tty_port_tty_set(&port->port, NULL); 173 kfree(termios); 174 kfree(tty); 175 } 176 set_bit(ASYNCB_INITIALIZED, &port->port.flags); 177 } 178 /* Now that any required fake tty operations are completed restore 179 * the tty port count */ 180 --port->port.count; 181 /* The console is special in terms of closing the device so 182 * indicate this port is now acting as a system console. */ 183 port->console = 1; 184 185 mutex_unlock(&serial->disc_mutex); 186 return retval; 187 188 free_termios: 189 kfree(termios); 190 tty_port_tty_set(&port->port, NULL); 191 free_tty: 192 kfree(tty); 193 reset_open_count: 194 port->port.count = 0; 195 usb_autopm_put_interface(serial->interface); 196 error_get_interface: 197 usb_serial_put(serial); 198 mutex_unlock(&serial->disc_mutex); 199 return retval; 200 } 201 202 static void usb_console_write(struct console *co, 203 const char *buf, unsigned count) 204 { 205 static struct usbcons_info *info = &usbcons_info; 206 struct usb_serial_port *port = info->port; 207 struct usb_serial *serial; 208 int retval = -ENODEV; 209 210 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED) 211 return; 212 serial = port->serial; 213 214 if (count == 0) 215 return; 216 217 dbg("%s - port %d, %d byte(s)", __func__, port->number, count); 218 219 if (!port->console) { 220 dbg("%s - port not opened", __func__); 221 return; 222 } 223 224 while (count) { 225 unsigned int i; 226 unsigned int lf; 227 /* search for LF so we can insert CR if necessary */ 228 for (i = 0, lf = 0 ; i < count ; i++) { 229 if (*(buf + i) == 10) { 230 lf = 1; 231 i++; 232 break; 233 } 234 } 235 /* pass on to the driver specific version of this function if 236 it is available */ 237 if (serial->type->write) 238 retval = serial->type->write(NULL, port, buf, i); 239 else 240 retval = usb_serial_generic_write(NULL, port, buf, i); 241 dbg("%s - return value : %d", __func__, retval); 242 if (lf) { 243 /* append CR after LF */ 244 unsigned char cr = 13; 245 if (serial->type->write) 246 retval = serial->type->write(NULL, 247 port, &cr, 1); 248 else 249 retval = usb_serial_generic_write(NULL, 250 port, &cr, 1); 251 dbg("%s - return value : %d", __func__, retval); 252 } 253 buf += i; 254 count -= i; 255 } 256 } 257 258 static struct tty_driver *usb_console_device(struct console *co, int *index) 259 { 260 struct tty_driver **p = (struct tty_driver **)co->data; 261 262 if (!*p) 263 return NULL; 264 265 *index = co->index; 266 return *p; 267 } 268 269 static struct console usbcons = { 270 .name = "ttyUSB", 271 .write = usb_console_write, 272 .device = usb_console_device, 273 .setup = usb_console_setup, 274 .flags = CON_PRINTBUFFER, 275 .index = -1, 276 .data = &usb_serial_tty_driver, 277 }; 278 279 void usb_serial_console_disconnect(struct usb_serial *serial) 280 { 281 if (serial && serial->port && serial->port[0] 282 && serial->port[0] == usbcons_info.port) { 283 usb_serial_console_exit(); 284 usb_serial_put(serial); 285 } 286 } 287 288 void usb_serial_console_init(int serial_debug, int minor) 289 { 290 debug = serial_debug; 291 292 if (minor == 0) { 293 /* 294 * Call register_console() if this is the first device plugged 295 * in. If we call it earlier, then the callback to 296 * console_setup() will fail, as there is not a device seen by 297 * the USB subsystem yet. 298 */ 299 /* 300 * Register console. 301 * NOTES: 302 * console_setup() is called (back) immediately (from 303 * register_console). console_write() is called immediately 304 * from register_console iff CON_PRINTBUFFER is set in flags. 305 */ 306 dbg("registering the USB serial console."); 307 register_console(&usbcons); 308 } 309 } 310 311 void usb_serial_console_exit(void) 312 { 313 if (usbcons_info.port) { 314 unregister_console(&usbcons); 315 usbcons_info.port->console = 0; 316 usbcons_info.port = NULL; 317 } 318 } 319 320