libkbd.c

驱动测试

/*
* This source code is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*       
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*
* File Name: libkbd.c							
*
* Reference:
*
* Author: Li Feng                                                   
*
* Description:
*
* 	
* 
* History:
* 02/23/2005  Li Feng    Created
*  
*
*CodeReview Log:
* 
*/
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <termios.h>

#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <linux/kd.h>
#include <stdlib.h>

#include "btype.h"
#include "libkbd.h"

typedef struct tagKBD_Param
{
	int kbd_fd;		/* file descriptor for keyboard */
	struct termios	startup_termios;		/* original terminal modes */
	int	startup_kbdmode;
	struct termios	work_termios;	/* startup_termios terminal modes */
}KBD_Param;

/*
 * Open the keyboard.
 * This is real simple, we just use a special file handle
 * that allows blocking I/O, and put the terminal into
 * character mode.
 */
HKBD KBD_Open (char *pDev)
{
	KBD_Param *pKBD;

	pKBD = (KBD_Param *)malloc(sizeof(KBD_Param));
	if(pKBD==NULL)
		return NULL;


	pKBD->kbd_fd = open(pDev, O_RDONLY | O_NOCTTY);
	if (pKBD->kbd_fd < 0)
	{
		free(pKBD);
		return NULL;
	}

	if (tcgetattr(pKBD->kbd_fd, &(pKBD->startup_termios)) < 0)
	{
		close(pKBD->kbd_fd);
		free(pKBD);
		return NULL;
	}

	pKBD->work_termios = pKBD->startup_termios;

	pKBD->work_termios.c_lflag &= ~(ICANON | ECHO  | ISIG);
	pKBD->work_termios.c_iflag &= ~(ISTRIP | IGNCR | ICRNL | INLCR | IXOFF | IXON);
	pKBD->work_termios.c_iflag |= IGNBRK;
	pKBD->work_termios.c_cc[VMIN] = 0;
	pKBD->work_termios.c_cc[VTIME] = 0;

	if(tcsetattr(pKBD->kbd_fd, TCSAFLUSH, &pKBD->work_termios) < 0)
	{
		close(pKBD->kbd_fd);
		free(pKBD);
		return NULL;
	}

	/* Put the keyboard into MEDIUMRAW mode.  Despite the name, this
	 * is really "mostly raw", with the kernel just folding long
	 * scancode sequences (e.g. E0 XX) onto single keycodes.
	 */
	ioctl(pKBD->kbd_fd, KDGKBMODE, &pKBD->startup_kbdmode);
	if (ioctl(pKBD->kbd_fd, KDSKBMODE, K_MEDIUMRAW) < 0) 
	{
		close(pKBD->kbd_fd);
		free(pKBD);
		return NULL;
	}
	return (HKBD)pKBD;
}

/*
 * Close the keyboard.
 * This resets the terminal modes.
 */
void KBD_Close(HKBD hKBD)
{
	KBD_Param *pKBD = (KBD_Param *)hKBD;
	if(pKBD==NULL)
		return;
	ioctl(pKBD->kbd_fd, KDSKBMODE, pKBD->startup_kbdmode);
	tcsetattr(pKBD->kbd_fd, TCSANOW, &pKBD->startup_termios);
	close(pKBD->kbd_fd);
	free(pKBD);
}

/*
 * This reads one keystroke from the keyboard, and the current state of
 * the mode keys (ALT, SHIFT, CTRL).  Returns -1 on error, 0 if no data
 * is ready, and 1 if data was read.  This is a non-blocking call.
 */
BOOL KBD_Read(HKBD hKBD, UINT8 *buf)
{
	int	cc;			/* characters read */
	unsigned char buf1;
	KBD_Param *pKBD = (KBD_Param *)hKBD;
	if(pKBD==NULL)
		return FALSE;
	
	do
	{
		cc = read(pKBD->kbd_fd, &buf1, 1);
	}while(cc==0);
	
	*buf = buf1;
	if (cc > 0)
	{
		return TRUE;
	}
	if ((cc < 0) && (errno != EINTR) && (errno != EAGAIN))
		return FALSE;
	return TRUE;
}