/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * 3-Byte Mouse Protocol
 */

#include <sys/param.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/vuid_event.h>
#include "vuidmice.h"

#define	VUID_BUT(b)		BUT((b*2)+1)

/*
 * VUID_BUT(0)	BUT(1)		LEFT  BUTTON
 * VUID_BUT(1)	BUT(3)		RIGHT BUTTON
 */

#define	MOUSE_BUTTON_L		(uchar_t)(0x20)	/* Left button pressed	*/
#define	MOUSE_BUTTON_R		(uchar_t)(0x10)	/* Right button pressed	*/

#define	MOUSE_START_CODE	(uchar_t)(0x40)	/* Start code in char	*/

#define	MOUSE_START		0		/* Beginning of packet	*/
#define	MOUSE_BUTTON		1		/* Got button status	*/
#define	MOUSE_DELTA_X		2		/* got delta X		*/

extern void VUID_PUTNEXT(queue_t *const, uchar_t, uchar_t, uchar_t, int);

int
VUID_OPEN(queue_t *const qp)
{
	STATEP->nbuttons = 2;

	return (0);
}

static void
vuidm3p_sendButtonEvent(queue_t *const qp)
{
	int b;

	if ((STATEP->buttons == 0x30) && (!STATEP->oldbuttons)) {
		/*
		 * both buttons going down simultaneously means button
		 * two going down
		 */
		vuidm3p_putnext(qp, (uchar_t)MS_MIDDLE, FE_PAIR_NONE, 0, 1);
		return;
	} else if ((!STATEP->buttons) && (STATEP->oldbuttons == 0x30)) {
		/*
		 * both buttons going up simultaneously means button
		 * two going up
		 */
		vuidm3p_putnext(qp, (uchar_t)MS_MIDDLE, FE_PAIR_NONE, 0, 0);
		return;
	}

	/*
	 * for each button, see if it has changed
	 */
	for (b = 0; b < 2; b++) {
		uchar_t mask = 0x20 >> b;

		if ((STATEP->buttons & mask) != (STATEP->oldbuttons & mask))
			VUID_PUTNEXT(qp, VUID_BUT(b), FE_PAIR_NONE, 0,
			    (STATEP->buttons & mask ? 1 : 0));
	}
}

void
vuidm3p(queue_t *const qp, mblk_t *mp)
{
	int r, code;
	uchar_t *bufp;

	bufp = mp->b_rptr;
	r = MBLKL(mp);

	for (r--; r >= 0; r--) {
		code = *bufp++;

		/* strip the high-order bit (mouse sends 7-bit data) */
		code &= 0x7f;

		switch (STATEP->state) {

		/*
		 * Start state. We stay here if the start code is not
		 * received thus forcing us back into sync. When we
		 * get a start code the	button mask comes with it
		 * forcing us to the next state.
		 */

		default:
		case MOUSE_START:
start_code:
			STATEP->deltax = STATEP->deltay = 0;

			/* look for sync */
			if ((code & MOUSE_START_CODE) == 0)
				break;

			STATEP->buttons = code & 0x30;

			if (STATEP->buttons != STATEP->oldbuttons) {
				vuidm3p_sendButtonEvent(qp);
				/*
				 * remember state
				 */
				STATEP->oldbuttons = STATEP->buttons;
			}

			/*
			 * bits 0 & 1 are bits 6 & 7 of X value
			 * (Sign extend them with the cast.)
			 */
			STATEP->deltax = (signed char)((code & 0x03) << 6);

			/*
			 * bits 2 & 3 are bits 6 & 7 of Y value
			 * (Sign extend them with the cast.)
			 */
			STATEP->deltay = (signed char)((code & 0x0c) << 4);

			/*
			 * go to the next state
			 */
			STATEP->state = MOUSE_BUTTON;
			break;

			/*
			 * We receive the remaining 6 bits of delta x, forcing
			 * us to the next state. We just piece the value of
			 * delta x together.
			 */
		case MOUSE_BUTTON:
			if (code & MOUSE_START_CODE) {
				STATEP->state = MOUSE_START;
				goto start_code;	/* restart */
			}

			STATEP->deltax |= code & 0x3f;
			STATEP->state = MOUSE_DELTA_X;
			break;

			/*
			 * The last part of delta Y, and the packet
			 * *may be* complete
			 */
		case MOUSE_DELTA_X:
			if (code & MOUSE_START_CODE) {
				STATEP->state = MOUSE_START;
				goto start_code;	/* restart */
			}

			STATEP->deltay |= code & 0x3f;

			/*
			 * generate motion Event
			 */
			if (STATEP->deltax)
				VUID_PUTNEXT(qp, (uchar_t)LOC_X_DELTA,
				    FE_PAIR_ABSOLUTE, (uchar_t)LOC_X_ABSOLUTE,
				    STATEP->deltax);

			if (STATEP->deltay)
				VUID_PUTNEXT(qp, (uchar_t)LOC_Y_DELTA,
				    FE_PAIR_ABSOLUTE, (uchar_t)LOC_Y_ABSOLUTE,
				    -STATEP->deltay);

			STATEP->deltax = STATEP->deltay = 0;
			break;
		}
	}

	freemsg(mp);
}