2 * USB Serial Console driver
4 * Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.com)
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.
10 * Thanks to Randy Dunlap for the original version of this code.
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>
27 struct usb_serial_port *port;
30 static struct usbcons_info usbcons_info;
31 static struct console usbcons;
34 * ------------------------------------------------------------
35 * USB Serial console driver
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.
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 * ------------------------------------------------------------
51 * The parsing of the command line works exactly like the
52 * serial.c code, except that the specifier is "ttyUSB" instead
55 static int usb_console_setup(struct console *co, char *options)
57 struct usbcons_info *info = &usbcons_info;
62 int cflag = CREAD | HUPCL | CLOCAL;
64 struct usb_serial *serial;
65 struct usb_serial_port *port;
67 struct tty_struct *tty;
68 struct ktermios *termios;
70 dbg ("%s", __FUNCTION__);
73 baud = simple_strtoul(options, NULL, 10);
75 while (*s >= '0' && *s <= '9')
82 doflow = (*s++ == 'r');
85 /* build a cflag setting */
112 * Set this to a sane value to prevent a divide error
137 * no need to check the index here: if the index is wrong, console
140 serial = usb_serial_get_by_index(co->index);
141 if (serial == NULL) {
142 /* no device is connected yet, sorry :( */
143 err ("No USB device connected to ttyUSB%i", co->index);
147 port = serial->port[0];
153 if (port->open_count == 1) {
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(port, NULL);
159 retval = usb_serial_generic_open(port, NULL);
161 port->open_count = 0;
165 err ("could not open USB console port");
169 if (serial->type->set_termios) {
170 struct ktermios dummy;
171 /* build up a fake tty structure so that the open call has something
172 * to look at to get the cflag value */
173 tty = kzalloc(sizeof(*tty), GFP_KERNEL);
175 err ("no more memory");
178 termios = kzalloc(sizeof(*termios), GFP_KERNEL);
180 err ("no more memory");
184 memset(&dummy, 0, sizeof(struct ktermios));
185 termios->c_cflag = cflag;
186 tty->termios = termios;
189 /* set up the initial termios settings */
190 serial->type->set_termios(port, &dummy);
200 static void usb_console_write(struct console *co, const char *buf, unsigned count)
202 static struct usbcons_info *info = &usbcons_info;
203 struct usb_serial_port *port = info->port;
204 struct usb_serial *serial;
205 int retval = -ENODEV;
207 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
209 serial = port->serial;
214 dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
216 if (!port->open_count) {
217 dbg ("%s - port not opened", __FUNCTION__);
224 /* search for LF so we can insert CR if necessary */
225 for (i=0, lf=0 ; i < count ; i++) {
226 if (*(buf + i) == 10) {
232 /* pass on to the driver specific version of this function if it is available */
233 if (serial->type->write)
234 retval = serial->type->write(port, buf, i);
236 retval = usb_serial_generic_write(port, buf, i);
237 dbg("%s - return value : %d", __FUNCTION__, retval);
239 /* append CR after LF */
240 unsigned char cr = 13;
241 if (serial->type->write)
242 retval = serial->type->write(port, &cr, 1);
244 retval = usb_serial_generic_write(port, &cr, 1);
245 dbg("%s - return value : %d", __FUNCTION__, retval);
252 static struct console usbcons = {
254 .write = usb_console_write,
255 .setup = usb_console_setup,
256 .flags = CON_PRINTBUFFER,
260 void usb_serial_console_disconnect(struct usb_serial *serial)
262 if (serial && serial->port && serial->port[0] && serial->port[0] == usbcons_info.port) {
263 usb_serial_console_exit();
264 usb_serial_put(serial);
268 void usb_serial_console_init (int serial_debug, int minor)
270 debug = serial_debug;
274 * Call register_console() if this is the first device plugged
275 * in. If we call it earlier, then the callback to
276 * console_setup() will fail, as there is not a device seen by
277 * the USB subsystem yet.
282 * console_setup() is called (back) immediately (from register_console).
283 * console_write() is called immediately from register_console iff
284 * CON_PRINTBUFFER is set in flags.
286 dbg ("registering the USB serial console.");
287 register_console(&usbcons);
291 void usb_serial_console_exit (void)
293 if (usbcons_info.port) {
294 unregister_console(&usbcons);
295 if (usbcons_info.port->open_count)
296 usbcons_info.port->open_count--;
297 usbcons_info.port = NULL;