/*
* USB Serial Console driver
*
* Copyright (C) 2001 - 2002 Greg Kroah-Hartman (greg@kroah.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* Thanks to Randy Dunlap for the original version of this code.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/console.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
static int debug;
struct usbcons_info {
int magic;
int break_flag;
struct usb_serial_port *port;
};
static struct usbcons_info usbcons_info;
static struct console usbcons;
/*
* ------------------------------------------------------------
* USB Serial console driver
*
* Much of the code here is copied from drivers/char/serial.c
* and implements a phony serial console in the same way that
* serial.c does so that in case some software queries it,
* it will get the same results.
*
* Things that are different from the way the serial port code
* does things, is that we call the lower level usb-serial
* driver code to initialize the device, and we set the initial
* console speeds based on the command line arguments.
* ------------------------------------------------------------
*/
/*
* The parsing of the command line works exactly like the
* serial.c code, except that the specifier is "ttyUSB" instead
* of "ttyS".
*/
static int usb_console_setup(struct console *co, char *options)
{
struct usbcons_info *info = &usbcons_info;
int baud = 9600;
int bits = 8;
int parity = 'n';
int doflow = 0;
int cflag = CREAD | HUPCL | CLOCAL;
char *s;
struct usb_serial *serial;
struct usb_serial_port *port;
int retval = 0;
struct tty_struct *tty;
struct ktermios *termios;
dbg ("%s", __FUNCTION__);
if (options) {
baud = simple_strtoul(options, NULL, 10);
s = options;
while (*s >= '0' && *s <= '9')
s++;
if (*s)
parity = *s++;
if (*s)
bits = *s++ - '0';
if (*s)
doflow = (*s++ == 'r');
}
/* build a cflag setting */
switch (baud) {
case 1200:
cflag |= B1200;
break;
case 2400:
cflag |= B2400;
break;
case 4800:
cflag |= B4800;
break;
case 19200:
cflag |= B19200;
break;
case 38400:
cflag |= B38400;
break;
case 57600:
cflag |= B57600;
break;
case 115200:
cflag |= B115200;
break;
case 9600:
default:
cflag |= B9600;
/*
* Set this to a sane value to prevent a divide error
*/
baud = 9600;
break;
}
switch (bits) {
case 7:
cflag |= CS7;
break;
default:
case 8:
cflag |= CS8;
break;
}
switch (parity) {
case 'o': case 'O':
cflag |= PARODD;
break;
case 'e': case 'E':
cflag |= PARENB;
break;
}
co->cflag = cflag;
/* grab the first serial port that happens to be connected */
serial = usb_serial_get_by_index(0);
if (serial == NULL) {
/* no device is connected yet, sorry :( */
err ("No USB device connected to ttyUSB0");
return -ENODEV;
}
port = serial->port[0];
port->tty = NULL;
info->port = port;
++port->open_count;
if (port->open_count == 1) {
/* only call the device specific open if this
* is the first time the port is opened */
if (serial->type->open)
retval = serial->type->open(port, NULL);
else
retval = usb_serial_generic_open(port, NULL);
if (retval)
port->open_count = 0;
}
if (retval) {
err ("could not open USB console port");
return retval;
}
if (serial->type->set_termios) {
struct ktermios dummy;
/* build up a fake tty structure so that the open call has something
* to look at to get the cflag value */
tty = kzalloc(sizeof(*tty), GFP_KERNEL);
if (!tty) {
err ("no more memory");
return -ENOMEM;
}
termios = kzalloc(sizeof(*termios), GFP_KERNEL);
if (!termios) {
err ("no more memory");
kfree (tty);
return -ENOMEM;
}
memset(&dummy, 0, sizeof(struct ktermios));
termios->c_cflag = cflag;
tty->termios = termios;
port->tty = tty;
/* set up the initial termios settings */
serial->type->set_termios(port, &dummy);
port->tty = NULL;
kfree (termios);
kfree (tty);
}
return retval;
}
static void usb_console_write(struct console *co, const char *buf, unsigned count)
{
static struct usbcons_info *info = &usbcons_info;
struct usb_serial_port *port = info->port;
struct usb_serial *serial;
int retval = -ENODEV;
if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED)
return;
serial = port->serial;
if (count == 0)
return;
dbg("%s - port %d, %d byte(s)", __FUNCTION__, port->number, count);
if (!port->open_count) {
dbg ("%s - port not opened", __FUNCTION__);
return;
}
while (count) {
unsigned int i;
unsigned int lf;
/* search for LF so we can insert CR if necessary */
for (i=0, lf=0 ; i < count ; i++) {
if (*(buf + i) == 10) {
lf = 1;
i++;
break;
}
}
/* pass on to the driver specific version of this function if it is available */
if (serial->type->write)
retval = serial->type->write(port, buf, i);
else
retval = usb_serial_generic_write(port, buf, i);
dbg("%s - return value : %d", __FUNCTION__, retval);
if (lf) {
/* append CR after LF */
unsigned char cr = 13;
if (serial->type->write)
retval = serial->type->write(port, &cr, 1);
else
retval = usb_serial_generic_write(port, &cr, 1);
dbg("%s - return value : %d", __FUNCTION__, retval);
}
buf += i;
count -= i;
}
}
static struct console usbcons = {
.name = "ttyUSB",
.write = usb_console_write,
.setup = usb_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
void usb_serial_console_disconnect(struct usb_serial *serial)
{
if (serial && serial->port && serial->port[0] && serial->port[0] == usbcons_info.port) {
usb_serial_console_exit();
usb_serial_put(serial);
}
}
void usb_serial_console_init (int serial_debug, int minor)
{
debug = serial_debug;
if (minor == 0) {
/*
* Call register_console() if this is the first device plugged
* in. If we call it earlier, then the callback to
* console_setup() will fail, as there is not a device seen by
* the USB subsystem yet.
*/
/*
* Register console.
* NOTES:
* console_setup() is called (back) immediately (from register_console).
* console_write() is called immediately from register_console iff
* CON_PRINTBUFFER is set in flags.
*/
dbg ("registering the USB serial console.");
register_console(&usbcons);
}
}
void usb_serial_console_exit (void)
{
if (usbcons_info.port) {
unregister_console(&usbcons);
if (usbcons_info.port->open_count)
usbcons_info.port->open_count--;
usbcons_info.port = NULL;
}
}
