mou_ps2.c

在ｅｃｏｓ 下mingui 的移植开发

/*
 * ps/2 Mouse Driver *  By Song Lixin 2000/11/17 
 * Take examples of MicroWindows and LibGGI.
 */

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>

#include "common.h"
#include "misc.h"
#include "ial.h"
#include "gal.h"
#include "native.h"

#define	SCALE		3	/* default scaling factor for acceleration */
#define	THRESH		5	/* default threshhold for acceleration */

#define PS2_SCALE11	230	/* Set 1:1 scale factor */
#define PS2_SCALE21	231	/* Set 2:1 scale factor */
#define PS2_SETRES	232	/* Set resolution */
#define PS2_GETSCALE	233	/* Get scale factor */
#define PS2_SETSTREAM	234	/* Set stream mode */
#define PS2_SETSAMPLE	243	/* Set sample rate */
#define PS2_ENABLE	244	/* Enable PS/2 device */
#define PS2_DISABLE	245	/* Disable PS/2 device */
#define PS2_DEFAULT	246	/* Set default settings */
#define PS2_RESET	255	/* Reset PS/2 device */
#define PS2_DEV_FILE	"/dev/psaux"

static gal_uint8 initdata_ps2[] = 
/* Make sure the mouse is enabled and in a sane state */
{ PS2_DEFAULT, PS2_SCALE11, PS2_ENABLE };

static int  	PS2_Open(void);
static void 	PS2_Close(void);
static int  	PS2_GetButtonInfo(void);
static void		PS2_GetDefaultAccel(int *pscale,int *pthresh);
static int  	PS2_Read(int *dx, int *dy, int *dz, int *bp);

MOUSEDEVICE mousedev_PS2 = {
	PS2_Open,
	PS2_Close,
	PS2_GetButtonInfo,
	PS2_GetDefaultAccel,
	PS2_Read
};

static int mouse_fd;

/*
 * Open up the mouse device.
 * Returns the fd if successful, or negative if unsuccessful.
 */
static int PS2_Open(void)
{
	mouse_fd = open (PS2_DEV_FILE, O_RDONLY | O_NOCTTY | O_NONBLOCK);
	if (mouse_fd < 0) 
			return -1;
	write(mouse_fd, initdata_ps2, sizeof(initdata_ps2));
	return mouse_fd;
}

/*
 * Close the mouse device.
 */
static void PS2_Close(void)
{
	if (mouse_fd > 0)
		close(mouse_fd);
	mouse_fd = 0;
}

/*
 * Get mouse buttons supported
 */
static int PS2_GetButtonInfo(void)
{
	return BUTTON_L | BUTTON_M | BUTTON_R;
}

/*
 * Get default mouse acceleration settings
 */
static void PS2_GetDefaultAccel(int *pscale,int *pthresh)
{
	*pscale = SCALE;
	*pthresh = THRESH;
}

/*
 * Attempt to read bytes from the mouse and interpret them.
 * Returns -1 on error, 0 if either no bytes were read or not enough
 * was read for a complete state, or 1 if the new state was read.
 * When a new state is read, the current buttons and x and y deltas
 * are returned.  This routine does not block.
 */
static int PS2_Read(int *dx, int *dy, int *dz, int *bp)
{
	static unsigned char buf[3];
	static int nbytes;
	int n;
	int buttons[4] = { 0, 4, 1, 5};

	while((n = read(mouse_fd, &buf[nbytes], 3 - nbytes))) {
		if(n < 0) {
			if ((errno == EINTR) || (errno == EAGAIN))
				return 0;
			else return -1;
		}

		nbytes += n;

		if(nbytes == 3) {
			/* Check header byte. */
			if ((buf[0] & 0xc0) != 0) {
				buf[0] = buf[1];
				buf[1] = buf[2];
				nbytes = 2;
				return -1;
			}

			*bp = buttons[(buf[0] & 0x07)];
			*dx = (buf[0] & 0x10) ? buf[1] - 256 : buf[1];
			*dy = (buf[0] & 0x20) ? -(buf[2] - 256) : -buf[2];

			*dz = 0;
			nbytes = 0;
			return 1;
		}
	}
	return 0;
}