kbdattach.c

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/*
 * File Name  : kbdattach.c
 *
 * Description: Keyboard Driver line discipline attach program
 */

/*
 * This file is part of kbdattach.
 *
 * kbdattach is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * kbdattach is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * Copyright (C) 2008 iRex Technologies B.V.
 * All rights reserved.
 *
 * Based on inputattach.c by Vojtech Pavlik
 */

//----------------------------------------------------------------------------
// Include Files
//----------------------------------------------------------------------------

// system include files, between < >
#include <linux/serio.h>

#include <sys/types.h>
#include <sys/ioctl.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>


//----------------------------------------------------------------------------
// Type Declarations
//----------------------------------------------------------------------------


//----------------------------------------------------------------------------
// Global Constants
//----------------------------------------------------------------------------

#define ION_LDISC           N_MOUSE
#define ION_SERIO_TYPE      SERIO_STOWAWAY
#define ION_SERIO_FLAGS     CS8
#define ION_SERIO_SPEED     B115200


//----------------------------------------------------------------------------
// Static Variables
//----------------------------------------------------------------------------


//============================================================================
// Local Function Definitions
//============================================================================

/* static int readchar(int fd, unsigned char *c, int timeout); */
static void setline(int fd, int flags, int speed);

//============================================================================
// Functions Implementation
//============================================================================

int main(int argc, char **argv)
{
    unsigned long devt;
    int ldisc;
    int fd;
   
    // open device
    if ((fd = open(argv[1], O_RDWR | O_NOCTTY | O_NONBLOCK)) < 0) {
        fprintf(stderr, "kbdattach: can't open device\n");
        return 1;
    }

    // set speed and flags
    setline(fd, ION_SERIO_FLAGS, ION_SERIO_SPEED);

    // flush input junk
    // while (!readchar(fd, &c, 100)); 
    // do device init if required

    // set line discipline
    ldisc = ION_LDISC; 
    if(ioctl(fd, TIOCSETD, &ldisc)) {
        fprintf(stderr, "kbdattach: can't set line discipline\n"); 
        return 1;
    }

    // set device type
    devt = ION_SERIO_TYPE;
    if(ioctl(fd, SPIOCSTYPE, &devt)) {
        fprintf(stderr, "kbdattach: can't set device type\n");
        return 1;
    }

    daemon(0,0);

    read(fd, NULL, 0);

    // reset line discipline
    ldisc = 0;
    ioctl(fd, TIOCSETD, &ldisc);
    close(fd);

    return 0;
}


/*
static int readchar(int fd, unsigned char *c, int timeout)
{
    struct timeval tv;
    fd_set set;
    
    tv.tv_sec = 0;
    tv.tv_usec = timeout * 1000;

    FD_ZERO(&set);
    FD_SET(fd, &set);

    if (!select(fd+1, &set, NULL, NULL, &tv)) return -1;
    if (read(fd, c, 1) != 1) return -1;

    return 0;
}
*/


static void setline(int fd, int flags, int speed)
{
    struct termios t;

    tcgetattr(fd, &t);

    t.c_cflag = flags | CREAD | HUPCL | CLOCAL;
    t.c_iflag = IGNBRK | IGNPAR;
    t.c_oflag = 0;
    t.c_lflag = 0;
    t.c_cc[VMIN ] = 1;
    t.c_cc[VTIME] = 0;

    cfsetispeed(&t, speed);
    cfsetospeed(&t, speed);

    tcsetattr(fd, TCSANOW, &t);
}