git: purgatorio

ref: babf901b4a508c3ec5d1f89655f10377bbdf9637
dir: /os/pc/ps2mouse.c/

#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "../port/error.h"
#include "io.h"

/*
 *  mouse types
 */
enum
{
	Mouseother=	0,
	Mouseserial=	1,
	MousePS2=	2,
};

static int mousetype;

/*
 *  ps/2 mouse message is three bytes
 *
 *	byte 0 -	0 0 SDY SDX 1 M R L
 *	byte 1 -	DX
 *	byte 2 -	DY
 *
 *  shift & left button is the same as middle button
 */
static void
ps2mouseputc(int c, int shift)
{
	static short msg[3];
	static int nb;
	static uchar b[] = {0, 1, 4, 5, 2, 3, 6, 7, 0, 1, 2, 5, 2, 3, 6, 7 };
	int buttons, dx, dy;

	/* 
	 *  check byte 0 for consistency
	 */
	if(nb==0 && (c&0xc8)!=0x08)
		return;

	msg[nb] = c;
	if(++nb == 3){
		nb = 0;
		if(msg[0] & 0x10)
			msg[1] |= 0xFF00;
		if(msg[0] & 0x20)
			msg[2] |= 0xFF00;

		buttons = b[(msg[0]&7) | (shift ? 8 : 0)];
		dx = msg[1];
		dy = -msg[2];
		mousetrack(buttons, dx, dy, 1);
	}
	return;
}

/*
 *  set up a ps2 mouse
 */
static void
ps2mouse(void)
{
	if(mousetype == MousePS2)
		return;

	i8042auxenable(ps2mouseputc);
	/* make mouse streaming, enabled */
	i8042auxcmd(0xEA);
	i8042auxcmd(0xF4);

	mousetype = MousePS2;
}

void
ps2mouselink(void)
{
	/*
	 * hack
	 */
	ps2mouse();
}