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 23static int debug; 24 25struct usbcons_info { 26 int magic; 27 int break_flag; 28 struct usb_serial_port *port; 29}; 30 31static struct usbcons_info usbcons_info; 32static 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 */ 56static 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 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 tty_port_tty_set(&port->port, tty); 145 tty->driver = usb_serial_tty_driver; 146 tty->index = co->index; 147 if (tty_init_termios(tty)) { 148 retval = -ENOMEM; 149 err("no more memory"); 150 goto free_tty; 151 } 152 } 153 154 /* only call the device specific open if this 155 * is the first time the port is opened */ 156 if (serial->type->open) 157 retval = serial->type->open(NULL, port); 158 else 159 retval = usb_serial_generic_open(NULL, port); 160 161 if (retval) { 162 err("could not open USB console port"); 163 goto fail; 164 } 165 166 if (serial->type->set_termios) { 167 tty->termios->c_cflag = cflag; 168 tty_termios_encode_baud_rate(tty->termios, baud, baud); 169 memset(&dummy, 0, sizeof(struct ktermios)); 170 serial->type->set_termios(tty, port, &dummy); 171 172 tty_port_tty_set(&port->port, NULL); 173 kfree(tty); 174 } 175 set_bit(ASYNCB_INITIALIZED, &port->port.flags); 176 } 177 /* Now that any required fake tty operations are completed restore 178 * the tty port count */ 179 --port->port.count; 180 /* The console is special in terms of closing the device so 181 * indicate this port is now acting as a system console. */ 182 port->port.console = 1; 183 184 mutex_unlock(&serial->disc_mutex); 185 return retval; 186 187 fail: 188 tty_port_tty_set(&port->port, NULL); 189 free_tty: 190 kfree(tty); 191 reset_open_count: 192 port->port.count = 0; 193 usb_autopm_put_interface(serial->interface); 194 error_get_interface: 195 usb_serial_put(serial); 196 mutex_unlock(&serial->disc_mutex); 197 return retval; 198} 199 200static void usb_console_write(struct console *co, 201 const char *buf, unsigned count) 202{ 203 static struct usbcons_info *info = &usbcons_info; 204 struct usb_serial_port *port = info->port; 205 struct usb_serial *serial; 206 int retval = -ENODEV; 207 208 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED) 209 return; 210 serial = port->serial; 211 212 if (count == 0) 213 return; 214 215 dbg("%s - port %d, %d byte(s)", __func__, port->number, count); 216 217 if (!port->port.console) { 218 dbg("%s - port not opened", __func__); 219 return; 220 } 221 222 while (count) { 223 unsigned int i; 224 unsigned int lf; 225 /* search for LF so we can insert CR if necessary */ 226 for (i = 0, lf = 0 ; i < count ; i++) { 227 if (*(buf + i) == 10) { 228 lf = 1; 229 i++; 230 break; 231 } 232 } 233 /* pass on to the driver specific version of this function if 234 it is available */ 235 if (serial->type->write) 236 retval = serial->type->write(NULL, port, buf, i); 237 else 238 retval = usb_serial_generic_write(NULL, port, buf, i); 239 dbg("%s - return value : %d", __func__, retval); 240 if (lf) { 241 /* append CR after LF */ 242 unsigned char cr = 13; 243 if (serial->type->write) 244 retval = serial->type->write(NULL, 245 port, &cr, 1); 246 else 247 retval = usb_serial_generic_write(NULL, 248 port, &cr, 1); 249 dbg("%s - return value : %d", __func__, retval); 250 } 251 buf += i; 252 count -= i; 253 } 254} 255 256static struct tty_driver *usb_console_device(struct console *co, int *index) 257{ 258 struct tty_driver **p = (struct tty_driver **)co->data; 259 260 if (!*p) 261 return NULL; 262 263 *index = co->index; 264 return *p; 265} 266 267static struct console usbcons = { 268 .name = "ttyUSB", 269 .write = usb_console_write, 270 .device = usb_console_device, 271 .setup = usb_console_setup, 272 .flags = CON_PRINTBUFFER, 273 .index = -1, 274 .data = &usb_serial_tty_driver, 275}; 276 277void usb_serial_console_disconnect(struct usb_serial *serial) 278{ 279 if (serial && serial->port && serial->port[0] 280 && serial->port[0] == usbcons_info.port) { 281 usb_serial_console_exit(); 282 usb_serial_put(serial); 283 } 284} 285 286void usb_serial_console_init(int serial_debug, int minor) 287{ 288 debug = serial_debug; 289 290 if (minor == 0) { 291 /* 292 * Call register_console() if this is the first device plugged 293 * in. If we call it earlier, then the callback to 294 * console_setup() will fail, as there is not a device seen by 295 * the USB subsystem yet. 296 */ 297 /* 298 * Register console. 299 * NOTES: 300 * console_setup() is called (back) immediately (from 301 * register_console). console_write() is called immediately 302 * from register_console iff CON_PRINTBUFFER is set in flags. 303 */ 304 dbg("registering the USB serial console."); 305 register_console(&usbcons); 306 } 307} 308 309void usb_serial_console_exit(void) 310{ 311 if (usbcons_info.port) { 312 unregister_console(&usbcons); 313 usbcons_info.port->port.console = 0; 314 usbcons_info.port = NULL; 315 } 316} 317