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>
23 #include "usb-serial.h"
28 struct usb_serial_port *port;
31 static struct usbcons_info usbcons_info;
32 static struct console usbcons;
35 * ------------------------------------------------------------
36 * USB Serial console driver
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.
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 * ------------------------------------------------------------
52 * The parsing of the command line works exactly like the
53 * serial.c code, except that the specifier is "ttyUSB" instead
56 static int usb_console_setup(struct console *co, char *options)
58 struct usbcons_info *info = &usbcons_info;
63 int cflag = CREAD | HUPCL | CLOCAL;
65 struct usb_serial *serial;
66 struct usb_serial_port *port;
68 struct tty_struct *tty;
69 struct termios *termios;
71 dbg ("%s", __FUNCTION__);
74 baud = simple_strtoul(options, NULL, 10);
76 while (*s >= '0' && *s <= '9')
83 doflow = (*s++ == 'r');
86 /* build a cflag setting */
113 * Set this to a sane value to prevent a divide error
137 /* grab the first serial port that happens to be connected */
138 serial = usb_serial_get_by_index(0);
139 if (serial == NULL) {
140 /* no device is connected yet, sorry :( */
141 err ("No USB device connected to ttyUSB0");
145 port = serial->port[0];
151 if (port->open_count == 1) {
152 /* only call the device specific open if this
153 * is the first time the port is opened */
154 if (serial->type->open)
155 retval = serial->type->open(port, NULL);
157 retval = usb_serial_generic_open(port, NULL);
159 port->open_count = 0;
163 err ("could not open USB console port");
167 if (serial->type->set_termios) {
168 /* build up a fake tty structure so that the open call has something
169 * to look at to get the cflag value */
170 tty = kmalloc (sizeof (*tty), GFP_KERNEL);
172 err ("no more memory");
175 termios = kmalloc (sizeof (*termios), GFP_KERNEL);
177 err ("no more memory");
181 memset (tty, 0x00, sizeof(*tty));
182 memset (termios, 0x00, sizeof(*termios));
183 termios->c_cflag = cflag;
184 tty->termios = termios;
187 /* set up the initial termios settings */
188 serial->type->set_termios(port, NULL);
197 static void usb_console_write(struct console *co, const char *buf, unsigned count)
199 static struct usbcons_info *info = &usbcons_info;
200 struct usb_serial_port *port = info->port;
201 struct usb_serial *serial;
202 int retval = -ENODEV;
204 if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
206 serial = port->serial;
211 dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
213 if (!port->open_count) {
214 dbg ("%s - port not opened", __FUNCTION__);
221 /* search for LF so we can insert CR if necessary */
222 for (i=0, lf=0 ; i < count ; i++) {
223 if (*(buf + i) == 10) {
229 /* pass on to the driver specific version of this function if it is available */
230 if (serial->type->write)
231 retval = serial->type->write(port, buf, i);
233 retval = usb_serial_generic_write(port, buf, i);
234 dbg("%s - return value : %d", __FUNCTION__, retval);
236 /* append CR after LF */
237 unsigned char cr = 13;
238 if (serial->type->write)
239 retval = serial->type->write(port, &cr, 1);
241 retval = usb_serial_generic_write(port, &cr, 1);
242 dbg("%s - return value : %d", __FUNCTION__, retval);
249 static struct console usbcons = {
251 .write = usb_console_write,
252 .setup = usb_console_setup,
253 .flags = CON_PRINTBUFFER,
257 void usb_serial_console_disconnect(struct usb_serial *serial)
259 if (serial && serial->port && serial->port[0] && serial->port[0] == usbcons_info.port) {
260 usb_serial_console_exit();
261 usb_serial_put(serial);
265 void usb_serial_console_init (int serial_debug, int minor)
267 debug = serial_debug;
271 * Call register_console() if this is the first device plugged
272 * in. If we call it earlier, then the callback to
273 * console_setup() will fail, as there is not a device seen by
274 * the USB subsystem yet.
279 * console_setup() is called (back) immediately (from register_console).
280 * console_write() is called immediately from register_console iff
281 * CON_PRINTBUFFER is set in flags.
283 dbg ("registering the USB serial console.");
284 register_console(&usbcons);
288 void usb_serial_console_exit (void)
290 if (usbcons_info.port) {
291 unregister_console(&usbcons);
292 if (usbcons_info.port->open_count)
293 usbcons_info.port->open_count--;
294 usbcons_info.port = NULL;