/*
 * 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.
 */

/*
 * 5-Byte Mouse Protocol
 */

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

#define LOGI_NUMBUTTONS         3               /* Number of buttons    */

#define LOGI_BMASK              (uchar_t)7      /* Button mask in packet */
#define LOGI_NOT_BMASK          (uchar_t)(~LOGI_BMASK) /* Rest of the bits */
#define LOGI_START_CODE         (uchar_t)(0x80) /* Start code in char   */

#define LOGI_START              0               /* Beginning of packet  */
#define LOGI_BUTTON             1               /* Got button status    */
#define LOGI_DELTA_X1           2               /* First of 2 delta X   */
#define LOGI_DELTA_Y1           3               /* First of 2 delta Y   */
#define LOGI_DELTA_X2           4               /* Second of 2 delta X  */

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

int
VUID_OPEN(queue_t *const qp)
{
        /*
         * The current kdmconfig tables imply that this module can be used
         * for both 2- and 3- button mice, so based on that evidence we
         * can't assume a constant.  I don't know whether it's possible
         * to autodetect.
         */
        STATEP->nbuttons = 0;   /* Don't know. */

        return (0);
}

static void
vuidm5p_sendButtonEvent(queue_t *const qp)
{
        int b;

        /* for each button, see if it has changed */
        for (b = 0; b < 3; b++) {
                uchar_t mask = 4 >> b;

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

void
vuidm5p(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++;

                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:
resync:
                case LOGI_START:
                        if ((code & LOGI_NOT_BMASK) != LOGI_START_CODE)
                                break;

                        STATEP->state   = LOGI_BUTTON;
                        STATEP->deltax  = STATEP->deltay = 0;
                        STATEP->buttons = (~code) & LOGI_BMASK;
                                                /* or xlate[code & ] */
                        break;

                case LOGI_BUTTON:
                        /*
                         * We receive the first of 2 delta x which forces us
                         * to the next state. We just add the values of each
                         * delta x together.
                         */
                        if ((code & LOGI_NOT_BMASK) == LOGI_START_CODE) {
                                STATEP->state = LOGI_START;
                                goto resync;
                        }

                        /* (The cast sign extends the 8-bit value.) */
                        STATEP->deltax += (signed char)code;
                        STATEP->state = LOGI_DELTA_X1;
                        break;

                case LOGI_DELTA_X1:
                        /*
                         * The first of 2 delta y. We just add
                         * the 2 delta y together
                         */
                        if ((code & LOGI_NOT_BMASK) == LOGI_START_CODE) {
                                STATEP->state = LOGI_START;
                                goto resync;
                        }

                        /* (The cast sign extends the 8-bit value.) */
                        STATEP->deltay += (signed char)code;
                        STATEP->state = LOGI_DELTA_Y1;
                        break;

                case LOGI_DELTA_Y1:
                        /*
                         * The second of 2 delta x. We just add
                         * the 2 delta x together.
                         */
                        if ((code & LOGI_NOT_BMASK) == LOGI_START_CODE) {
                                STATEP->state = LOGI_START;
                                goto resync;
                        }

                        /* (The cast sign extends the 8-bit value.) */
                        STATEP->deltax += (signed char)code;
                        STATEP->state = LOGI_DELTA_X2;
                        break;

                case LOGI_DELTA_X2:
                        /*
                         * The second of 2 delta y. We just add
                         * the 2 delta y together.
                         */
                        if ((code & LOGI_NOT_BMASK) == LOGI_START_CODE) {
                                STATEP->state = LOGI_START;
                                goto resync;
                        }

                        /* (The cast sign extends the 8-bit value.) */
                        STATEP->deltay += (signed char)code;
                        STATEP->state = LOGI_START;

                        /* check if motion has occurred and send event(s)... */
                        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;

                        /* see if the buttons have changed */
                        if (STATEP->buttons != STATEP->oldbuttons) {
                                /* buttons have changed */
                                vuidm5p_sendButtonEvent(qp);

                                /* update new button state */
                                STATEP->oldbuttons = STATEP->buttons;
                        }
                }
        }
        freemsg(mp);
}