/*      $NetBSD: ewsms.c,v 1.10 2021/08/07 16:18:53 thorpej Exp $       */

/*
 * Copyright (c) 2004 Steve Rumble
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * EWS4800 serial mouse driver attached to zs channel 0 at 4800 or 1200bps.
 * This layer feeds wsmouse.
 *
 * 5 byte packets: sync, x1, y1, x2, y2
 * sync format: binary 10000LMR (left, middle, right) 0 is down
 *
 * This driver is taken from sgimips, but ews4800 has the similar protocol.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ewsms.c,v 1.10 2021/08/07 16:18:53 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsmousevar.h>

#include <dev/ic/z8530reg.h>
#include <machine/z8530var.h>

#define EWSMS_BAUD              1200
#define EWSMS_BAUD1             4800

#define EWSMS_RXQ_LEN           64      /* power of 2 */
#define EWSMS_RXQ_LEN_MASK      (EWSMS_RXQ_LEN - 1)
#define EWSMS_NEXTRXQ(x)        (((x) + 1) & EWSMS_RXQ_LEN_MASK)

/* protocol */
#define EWSMS_SYNC0             0x80
#define EWSMS_SYNC1             0x88
#define EWSMS_SYNC_MASK         0xf8
#define EWSMS_SYNC_BTN_R        0x01
#define EWSMS_SYNC_BTN_M        0x02
#define EWSMS_SYNC_BTN_L        0x04
#define EWSMS_SYNC_BTN_MASK     \
        (EWSMS_SYNC_BTN_R|EWSMS_SYNC_BTN_M|EWSMS_SYNC_BTN_L)

struct ewsms_softc {
        device_t sc_dev;

        /* tail-chasing fifo */
        uint8_t sc_rxq[EWSMS_RXQ_LEN];
        u_int sc_rxq_head;
        u_int sc_rxq_tail;

        /* 5-byte packet as described above */
        int8_t  sc_packet[5];
#define EWSMS_PACKET_SYNC       0
#define EWSMS_PACKET_X1         1
#define EWSMS_PACKET_Y1         2
#define EWSMS_PACKET_X2         3
#define EWSMS_PACKET_Y2         4

        u_int sc_state;
#define EWSMS_STATE_SYNC        0x01
#define EWSMS_STATE_X1          0x02
#define EWSMS_STATE_Y1          0x04
#define EWSMS_STATE_X2          0x08
#define EWSMS_STATE_Y2          0x10

        u_int sc_baud;
        u_int sc_flags;
#define EWSMS_F_FASTBAUD        0x01
#define EWSMS_F_RSTCMD          0x02
#define EWSMS_F_SWAPBTN         0x04
#define EWSMS_F_SYNC1           0x08

        /* wsmouse bits */
        int sc_enabled;
        device_t sc_wsmousedev;
};

static int  ewsms_zsc_match(device_t, cfdata_t, void *);
static void ewsms_zsc_attach(device_t, device_t, void *);
static int  ewsms_zsc_reset(struct zs_chanstate *);
static void ewsms_zsc_rxint(struct zs_chanstate *);
static void ewsms_zsc_txint(struct zs_chanstate *);
static void ewsms_zsc_stint(struct zs_chanstate *, int);
static void ewsms_zsc_softint(struct zs_chanstate *);

static void ewsms_wsmouse_input(struct ewsms_softc *);
static int  ewsms_wsmouse_enable(void *);
static void ewsms_wsmouse_disable(void *);
static int  ewsms_wsmouse_ioctl(void *, u_long, void *, int, struct lwp *);

CFATTACH_DECL_NEW(ewsms_zsc, sizeof(struct ewsms_softc),
    ewsms_zsc_match, ewsms_zsc_attach, NULL, NULL);

static struct zsops ewsms_zsops = {
        ewsms_zsc_rxint,
        ewsms_zsc_stint,
        ewsms_zsc_txint,
        ewsms_zsc_softint
};

static const struct wsmouse_accessops ewsms_wsmouse_accessops = {
        ewsms_wsmouse_enable,
        ewsms_wsmouse_ioctl,
        ewsms_wsmouse_disable
};

int
ewsms_zsc_match(device_t parent, cfdata_t cf, void *aux)
{
        struct zsc_softc *zsc = device_private(parent);
        struct zsc_attach_args *zsc_args = aux;

        /* mouse on channel A */
        if ((zsc->zsc_flags & 0x0001 /* kbms port */) != 0 &&
            zsc_args->channel == 0)
                /* prior to generic zstty(4) */
                return 3;

        return 0;
}

void
ewsms_zsc_attach(device_t parent, device_t self, void *aux)
{
        struct ewsms_softc *sc = device_private(self);
        struct zsc_softc *zsc = device_private(parent);
        struct zsc_attach_args *zsc_args = aux;
        struct zs_chanstate *cs;
        struct wsmousedev_attach_args wsmaa;
        int channel;

        /* Establish ourself with the MD z8530 driver */
        channel = zsc_args->channel;
        cs = zsc->zsc_cs[channel];
        cs->cs_ops = &ewsms_zsops;
        cs->cs_private = sc;

        sc->sc_dev = self;
        sc->sc_enabled = 0;
        sc->sc_rxq_head = 0;
        sc->sc_rxq_tail = 0;
        sc->sc_state = EWSMS_STATE_SYNC;

        if (zsc->zsc_flags & 0x0002) {
                sc->sc_flags |= EWSMS_F_RSTCMD;
                sc->sc_flags |= EWSMS_F_FASTBAUD;
                sc->sc_flags |= EWSMS_F_SWAPBTN;
                sc->sc_flags |= EWSMS_F_SYNC1;
        }

        ewsms_zsc_reset(cs);

        aprint_normal(": baud rate %d\n", EWSMS_BAUD);

        /* attach wsmouse */
        wsmaa.accessops = &ewsms_wsmouse_accessops;
        wsmaa.accesscookie = sc;
        sc->sc_wsmousedev = config_found(self, &wsmaa, wsmousedevprint,
            CFARGS_NONE);
}

int
ewsms_zsc_reset(struct zs_chanstate *cs)
{
        struct ewsms_softc *sc = cs->cs_private;
        u_int baud;
        int i, s;
        static const uint8_t cmd[] =
            { 0x02, 0x52, 0x53, 0x3b, 0x4d, 0x54, 0x2c, 0x36, 0x0d };

        s = splzs();
        zs_write_reg(cs, 9, ZSWR9_A_RESET);
        cs->cs_preg[1] = ZSWR1_RIE;
        baud = EWSMS_BAUD;
        if (sc->sc_flags & EWSMS_F_FASTBAUD)
                baud = EWSMS_BAUD1;
        zs_set_speed(cs, baud);
        zs_loadchannelregs(cs);

        if (sc->sc_flags & EWSMS_F_RSTCMD) {
                for (i = 0; i < sizeof(cmd); i++)
                        zs_putc(cs, cmd[i]);
        }

        splx(s);

        return 0;
}

void
ewsms_zsc_rxint(struct zs_chanstate *cs)
{
        struct ewsms_softc *sc = cs->cs_private;
        uint8_t c, r;

        /* clear errors */
        r = zs_read_reg(cs, 1);
        if (r & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE))
                zs_write_csr(cs, ZSWR0_RESET_ERRORS);

        /* read byte and append to our queue */
        c = zs_read_data(cs);

        sc->sc_rxq[sc->sc_rxq_tail] = c;
        sc->sc_rxq_tail = EWSMS_NEXTRXQ(sc->sc_rxq_tail);

        cs->cs_softreq = 1;
}

/* We should never get here. */
void
ewsms_zsc_txint(struct zs_chanstate *cs)
{

        zs_write_reg(cs, 0, ZSWR0_RESET_TXINT);

        /* seems like the in thing to do */
        cs->cs_softreq = 1;
}

void
ewsms_zsc_stint(struct zs_chanstate *cs, int force)
{

        zs_write_csr(cs, ZSWR0_RESET_STATUS);
        cs->cs_softreq = 1;
}

void
ewsms_zsc_softint(struct zs_chanstate *cs)
{
        struct ewsms_softc *sc = cs->cs_private;
        uint8_t sync;

        /* No need to keep score if nobody is listening */
        if (!sc->sc_enabled) {
                sc->sc_rxq_head = sc->sc_rxq_tail;
                return;
        }

        /*
         * Here's the real action. Read a full packet and
         * then let wsmouse know what has happened.
         */
        while (sc->sc_rxq_head != sc->sc_rxq_tail) {
                int8_t c = sc->sc_rxq[sc->sc_rxq_head];

                switch (sc->sc_state) {
                case EWSMS_STATE_SYNC:
                        sync = EWSMS_SYNC0;
                        if (sc->sc_flags & EWSMS_F_SYNC1)
                                sync = EWSMS_SYNC1;
                        if ((c & EWSMS_SYNC_MASK) == sync) {
                                sc->sc_packet[EWSMS_PACKET_SYNC] = c;
                                sc->sc_state = EWSMS_STATE_X1;
                        }
                        break;

                case EWSMS_STATE_X1:
                        sc->sc_packet[EWSMS_PACKET_X1] = c;
                        sc->sc_state = EWSMS_STATE_Y1;
                        break;

                case EWSMS_STATE_Y1:
                        sc->sc_packet[EWSMS_PACKET_Y1] = c;
                        sc->sc_state = EWSMS_STATE_X2;
                        break;

                case EWSMS_STATE_X2:
                        sc->sc_packet[EWSMS_PACKET_X2] = c;
                        sc->sc_state = EWSMS_STATE_Y2;
                        break;

                case EWSMS_STATE_Y2:
                        sc->sc_packet[EWSMS_PACKET_Y2] = c;

                        /* tweak wsmouse */
                        ewsms_wsmouse_input(sc);

                        sc->sc_state = EWSMS_STATE_SYNC;
                }

                sc->sc_rxq_head = EWSMS_NEXTRXQ(sc->sc_rxq_head);
        }
}

/******************************************************************************
 * wsmouse glue
 ******************************************************************************/

static void
ewsms_wsmouse_input(struct ewsms_softc *sc)
{
        u_int btns;
        bool bl, bm, br;
        int dx, dy;

        btns = (uint8_t)sc->sc_packet[EWSMS_PACKET_SYNC] & EWSMS_SYNC_BTN_MASK;
        if (sc->sc_flags & EWSMS_F_SWAPBTN) {
                bl = (btns & EWSMS_SYNC_BTN_R) == 0;
                bm = (btns & EWSMS_SYNC_BTN_M) == 0;
                br = (btns & EWSMS_SYNC_BTN_L) == 0;
        } else {
                bl = (btns & EWSMS_SYNC_BTN_L) == 0;
                bm = (btns & EWSMS_SYNC_BTN_M) == 0;
                br = (btns & EWSMS_SYNC_BTN_R) == 0;
        }
        /* for wsmouse(4), 1 is down, 0 is up, most left button is LSB */
        btns = (bl ? (1 << 0) : 0) | (bm ? (1 << 1) : 0) | (br ? (1 << 2) : 0);

        /* delta values are signed */
        /* moving left is minus, moving right is plus */
        dx = (int)sc->sc_packet[EWSMS_PACKET_X1] +
             (int)sc->sc_packet[EWSMS_PACKET_X2];
        /* moving back is minus, moving front is plus */
        dy = (int)sc->sc_packet[EWSMS_PACKET_Y1] +
             (int)sc->sc_packet[EWSMS_PACKET_Y2];

        wsmouse_input(sc->sc_wsmousedev,
                        btns,
                        dx, dy, 0, 0,
                        WSMOUSE_INPUT_DELTA);
}

static int
ewsms_wsmouse_enable(void *cookie)
{
        struct ewsms_softc *sc = cookie;

        if (sc->sc_enabled)
                return EBUSY;

        sc->sc_state = EWSMS_STATE_SYNC;
        sc->sc_enabled = 1;

        return 0;
}

void
ewsms_wsmouse_disable(void *cookie)
{
        struct ewsms_softc *sc = cookie;

        sc->sc_enabled = 0;
}

static int
ewsms_wsmouse_ioctl(void *cookie, u_long cmd, void *data, int flag,
    struct lwp *l)
{

        switch (cmd) {
        case WSMOUSEIO_GTYPE:
                *(u_int *)data = 0;
                break;

#ifdef notyet
        case WSMOUSEIO_SRES:
        case WSMOUSEIO_SSCALE:
        case WSMOUSEIO_SRATE:
        case WSMOUSEIO_SCALIBCOORDS:
        case WSMOUSEIO_GCALIBCOORDS:
        case WSMOUSEIO_GETID:
#endif

        default:
                return EPASSTHROUGH;
        }

        return 0;
}