/*      $NetBSD: ms.c,v 1.42 2024/05/24 20:06:55 andvar Exp $ */

/*
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * All advertising materials mentioning features or use of this software
 * must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Lawrence Berkeley Laboratory.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *      @(#)ms.c        8.1 (Berkeley) 6/11/93
 */

/*
 * X68k mouse driver.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ms.c,v 1.42 2024/05/24 20:06:55 andvar Exp $");

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <sys/device.h>
#include <sys/signalvar.h>
#include <sys/mutex.h>

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

#include <arch/x68k/dev/event_var.h>
#include <machine/vuid_event.h>
#include <arch/x68k/dev/mfp.h>

#include "ioconf.h"
#include "locators.h"

/*
 * How many input characters we can buffer.
 * The port-specific var.h may override this.
 * Note: must be a power of two!
 */
#define MS_RX_RING_SIZE 256
#define MS_RX_RING_MASK (MS_RX_RING_SIZE-1)
/*
 * Output buffer.  Only need a few chars.
 */
#define MS_TX_RING_SIZE 16
#define MS_TX_RING_MASK (MS_TX_RING_SIZE-1)
/*
 * Mouse serial line is fixed at 4800 bps.
 */
#define MS_BPS 4800

/*
 * Send mouse commands per MS_TICK.
 */
#ifndef HZ
#define HZ              100
#endif
#define MS_TICK         2
#define MS_TIMEOUT_SEC  5
#define MS_TIMEOUT      ((MS_TIMEOUT_SEC * HZ) / MS_TICK)

/*
 * Mouse state.  A SHARP X1/X680x0 mouse is a fairly simple device,
 * producing three-byte blobs of the form:
 *
 *      b dx dy
 *
 * where b is the button state, encoded as 0x80|(buttons)---there are
 * two buttons (1=left, 2=right)---and dx,dy are X and Y delta values.
 *
 * It needs a trigger for the transmission.  When zs RTS negated, the
 * mouse begins the sequence.  RTS assertion has no effect.
 */
struct ms_softc {
        device_t ms_dev;                /* required first: base device */
        struct  zs_chanstate *ms_cs;

        struct callout ms_modem_ch;

        /* Flags to communicate with ms_softintr() */
        volatile int ms_intr_flags;
#define INTR_RX_OVERRUN 1
#define INTR_TX_EMPTY   2
#define INTR_ST_CHECK   4

        /*
         * The receive ring buffer.
         */
        u_int   ms_rbget;       /* ring buffer `get' index */
        volatile u_int  ms_rbput;       /* ring buffer `put' index */
        u_short ms_rbuf[MS_RX_RING_SIZE]; /* rr1, data pairs */

        /*
         * State of input translator
         */
        short   ms_byteno;              /* input byte number, for decode */
        char    ms_mb;                  /* mouse button state */
        char    ms_ub;                  /* user button state */
        int     ms_dx;                  /* delta-x */
        int     ms_dy;                  /* delta-y */
        int     ms_rts;                 /* MSCTRL */
        int     ms_nodata;

        /*
         * State of upper interface.
         */
        volatile int ms_ready;          /* event queue is ready */
        struct  evvar ms_events;        /* event queue state */
        kmutex_t ms_lock;
};

static int ms_match(device_t, cfdata_t, void *);
static void ms_attach(device_t, device_t, void *);
static void ms_trigger(struct zs_chanstate *, int);
static void ms_modem(void *);

CFATTACH_DECL_NEW(ms, sizeof(struct ms_softc),
    ms_match, ms_attach, NULL, NULL);

static void ms_rxint(struct zs_chanstate *);
static void ms_stint(struct zs_chanstate *, int);
static void ms_txint(struct zs_chanstate *);
static void ms_softint(struct zs_chanstate *);
static void ms_input(struct ms_softc *, int);

static struct zsops zsops_ms = {
        ms_rxint,       /* receive char available */
        ms_stint,       /* external/status */
        ms_txint,       /* xmit buffer empty */
        ms_softint,     /* process software interrupt */
};

static dev_type_open(msopen);
static dev_type_close(msclose);
static dev_type_read(msread);
static dev_type_ioctl(msioctl);
static dev_type_poll(mspoll);
static dev_type_kqfilter(mskqfilter);

const struct cdevsw ms_cdevsw ={
        .d_open = msopen,
        .d_close = msclose,
        .d_read = msread,
        .d_write = nowrite,
        .d_ioctl = msioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = mspoll,
        .d_mmap = nommap,
        .d_kqfilter = mskqfilter,
        .d_discard = nodiscard,
        .d_flag = 0
};

/*
 * ms_match: how is this zs channel configured?
 */
static int
ms_match(device_t parent, cfdata_t cf, void *aux)
{
        struct zsc_attach_args *args = aux;
        struct zsc_softc *zsc = device_private(parent);

        /* Exact match required for the mouse. */
        if (cf->cf_loc[ZSCCF_CHANNEL] != args->channel)
                return 0;
        if (args->channel != 1)
                return 0;
        if (&zsc->zsc_addr->zs_chan_b != (struct zschan *)ZSMS_PHYSADDR)
                return 0;

        return 2;
}

static void
ms_attach(device_t parent, device_t self, void *aux)
{
        struct ms_softc *ms = device_private(self);
        struct zsc_softc *zsc = device_private(parent);
        struct zs_chanstate *cs;
        int reset;

        ms->ms_dev = self;
        callout_init(&ms->ms_modem_ch, 0);
        mutex_init(&ms->ms_lock, MUTEX_DEFAULT, IPL_SERIAL);

        cs = zsc->zsc_cs[1];
        cs->cs_private = ms;
        cs->cs_ops = &zsops_ms;
        ms->ms_cs = cs;

        /* Initialize the speed, etc. */
        /* May need reset... */
        reset = ZSWR9_B_RESET;
        zs_write_reg(cs, 9, reset);
        /* We don't care about status or tx interrupts. */
        cs->cs_preg[1] = ZSWR1_RIE;
        cs->cs_preg[4] = ZSWR4_CLK_X16 | ZSWR4_TWOSB;
        (void)zs_set_speed(cs, MS_BPS);
        zs_loadchannelregs(cs);

        /* Initialize translator. */
        ms->ms_ready = 0;

        aprint_normal("\n");
}

/****************************************************************
 *  Entry points for /dev/mouse
 *  (open,close,read,write,...)
 ****************************************************************/

static int
msopen(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct ms_softc *ms;

        ms = device_lookup_private(&ms_cd, minor(dev));
        if (ms == NULL)
                return ENXIO;

        /* This is an exclusive open device. */
        if (ms->ms_events.ev_io)
                return EBUSY;
        ms->ms_events.ev_io = l->l_proc;
        ev_init(&ms->ms_events, device_xname(ms->ms_dev), &ms->ms_lock);

        ms->ms_ready = 1;               /* start accepting events */
        ms->ms_rts = 1;
        ms->ms_byteno = -1;
        ms->ms_nodata = 0;

        /* start sequencer */
        callout_reset(&ms->ms_modem_ch, MS_TICK, ms_modem, ms);

        return 0;
}

static int
msclose(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct ms_softc *ms;

        ms = device_lookup_private(&ms_cd, minor(dev));
        ms->ms_ready = 0;               /* stop accepting events */
        callout_stop(&ms->ms_modem_ch);
        ev_fini(&ms->ms_events);

        ms->ms_events.ev_io = NULL;
        return 0;
}

static int
msread(dev_t dev, struct uio *uio, int flags)
{
        struct ms_softc *ms;

        ms = device_lookup_private(&ms_cd, minor(dev));
        return ev_read(&ms->ms_events, uio, flags);
}

static int
msioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        struct ms_softc *ms;

        ms = device_lookup_private(&ms_cd, minor(dev));

        switch (cmd) {

        case FIONBIO:           /* we will remove this someday (soon???) */
                return 0;

        case FIOASYNC:
                ms->ms_events.ev_async = *(int *)data != 0;
                return 0;

        case FIOSETOWN:
                if (-*(int *)data != ms->ms_events.ev_io->p_pgid
                    && *(int *)data != ms->ms_events.ev_io->p_pid)
                        return EPERM;
                return 0;

        case TIOCSPGRP:
                if (*(int *)data != ms->ms_events.ev_io->p_pgid)
                        return EPERM;
                return 0;

        case VUIDGFORMAT:
                /* we only do firm_events */
                *(int *)data = VUID_FIRM_EVENT;
                return 0;

        case VUIDSFORMAT:
                if (*(int *)data != VUID_FIRM_EVENT)
                        return EINVAL;
                return 0;
        }
        return ENOTTY;
}

static int
mspoll(dev_t dev, int events, struct lwp *l)
{
        struct ms_softc *ms;

        ms = device_lookup_private(&ms_cd, minor(dev));
        return ev_poll(&ms->ms_events, events, l);
}

static int
mskqfilter(dev_t dev, struct knote *kn)
{
        struct ms_softc *ms;

        ms = device_lookup_private(&ms_cd, minor(dev));
        return ev_kqfilter(&ms->ms_events, kn);
}

/****************************************************************
 * Middle layer (translator)
 ****************************************************************/

/*
 * Called by our ms_softint() routine on input.
 */
static void
ms_input(struct ms_softc *ms, int c)
{
        struct firm_event *fe;
        int mb, ub, d, get, put, any;
        static const char to_one[] = { 1, 2, 2 };
        static const int to_id[] = { MS_LEFT, MS_RIGHT };

        /*
         * Discard input if not ready.  Drop sync on parity or framing
         * error; gain sync on button byte.
         */
        if (ms->ms_ready == 0)
                return;

        ms->ms_nodata = 0;
        /*
         * Run the decode loop, adding to the current information.
         * We add, rather than replace, deltas, so that if the event queue
         * fills, we accumulate data for when it opens up again.
         */
        switch (ms->ms_byteno) {

        case -1:
                return;

        case 0:
                /* buttons */
                ms->ms_byteno = 1;
                ms->ms_mb = c & 0x3;
                return;

        case 1:
                /* delta-x */
                ms->ms_byteno = 2;
                ms->ms_dx += (char)c;
                return;

        case 2:
                /* delta-y */
                ms->ms_byteno = -1;
                ms->ms_dy += (char)c;
                break;

        default:
                panic("ms_input");
                /* NOTREACHED */
        }

        /*
         * We have at least one event (mouse button, delta-X, or
         * delta-Y; possibly all three, and possibly two separate
         * button events).  Deliver these events until we are out
         * of changes or out of room.  As events get delivered,
         * mark them `unchanged'.
         */
        any = 0;
        get = ms->ms_events.ev_get;
        put = ms->ms_events.ev_put;
        fe = &ms->ms_events.ev_q[put];

        /* NEXT prepares to put the next event, backing off if necessary */
#define NEXT \
        if ((++put) % EV_QSIZE == get) { \
                put--; \
                goto out; \
        }
        /* ADVANCE completes the `put' of the event */
#define ADVANCE \
        fe++; \
        if (put >= EV_QSIZE) { \
                put = 0; \
                fe = &ms->ms_events.ev_q[0]; \
        } \

        mb = ms->ms_mb;
        ub = ms->ms_ub;
        while ((d = mb ^ ub) != 0) {
                /*
                 * Mouse button change.  Convert up to two changes
                 * to the `first' change, and drop it into the event queue.
                 */
                NEXT;
                d = to_one[d - 1];              /* from 1..3 to {1,2} */
                fe->id = to_id[d - 1];          /* from {1,2} to ID */
                fe->value = mb & d ? VKEY_DOWN : VKEY_UP;
                firm_gettime(fe);
                ADVANCE;
                ub ^= d;
                any++;
        }
        if (ms->ms_dx) {
                NEXT;
                fe->id = LOC_X_DELTA;
                fe->value = ms->ms_dx;
                firm_gettime(fe);
                ADVANCE;
                ms->ms_dx = 0;
                any++;
        }
        if (ms->ms_dy) {
                NEXT;
                fe->id = LOC_Y_DELTA;
                /*
                 * struct firm_events (derived from SunOS) defines
                 * moving up (forward) is positive. (see vuid_event.h)
                 * On the other hand, X680x0 mouse protocol reports
                 * moving down (backward) is positive.
                 *
                 * Note wsmouse(9) also defines moving upward is positive,
                 * but Xorg DIX layer requires moving down is positive.
                 */
                fe->value = -ms->ms_dy;
                firm_gettime(fe);
                ADVANCE;
                ms->ms_dy = 0;
                any++;
        }
out:
        if (any) {
                ms->ms_ub = ub;
                ms->ms_events.ev_put = put;
                ev_wakeup(&ms->ms_events);
        }
}

/****************************************************************
 * Interface to the lower layer (zscc)
 ****************************************************************/

static void
ms_rxint(struct zs_chanstate *cs)
{
        struct ms_softc *ms;
        int put, put_next;
        u_char c, rr1;

        ms = cs->cs_private;
        put = ms->ms_rbput;

        /*
         * First read the status, because reading the received char
         * destroys the status of this char.
         */
        rr1 = zs_read_reg(cs, 1);
        c = zs_read_data(cs);

        if (rr1 & (ZSRR1_FE | ZSRR1_DO | ZSRR1_PE)) {
                /* Clear the receive error. */
                zs_write_csr(cs, ZSWR0_RESET_ERRORS);
        }

        ms->ms_rbuf[put] = (c << 8) | rr1;
        put_next = (put + 1) & MS_RX_RING_MASK;

        /* Would overrun if increment makes (put==get). */
        if (put_next == ms->ms_rbget) {
                ms->ms_intr_flags |= INTR_RX_OVERRUN;
        } else {
                /* OK, really increment. */
                put = put_next;
        }

        /* Done reading. */
        ms->ms_rbput = put;

        /* Ask for softint() call. */
        cs->cs_softreq = 1;
}


static void
ms_txint(struct zs_chanstate *cs)
{
        struct ms_softc *ms;

        ms = cs->cs_private;
        zs_write_csr(cs, ZSWR0_RESET_TXINT);
        ms->ms_intr_flags |= INTR_TX_EMPTY;
        /* Ask for softint() call. */
        cs->cs_softreq = 1;
}


static void
ms_stint(struct zs_chanstate *cs, int force)
{
        struct ms_softc *ms;
        int rr0;

        ms = cs->cs_private;

        rr0 = zs_read_csr(cs);
        zs_write_csr(cs, ZSWR0_RESET_STATUS);

        /*
         * We have to accumulate status line changes here.
         * Otherwise, if we get multiple status interrupts
         * before the softint runs, we could fail to notice
         * some status line changes in the softint routine.
         * Fix from Bill Studenmund, October 1996.
         */
        cs->cs_rr0_delta |= (cs->cs_rr0 ^ rr0);
        cs->cs_rr0 = rr0;
        ms->ms_intr_flags |= INTR_ST_CHECK;

        /* Ask for softint() call. */
        cs->cs_softreq = 1;
}


static void
ms_softint(struct zs_chanstate *cs)
{
        struct ms_softc *ms;
        int get, c;
        int intr_flags;
        u_short ring_data;

        ms = cs->cs_private;

        mutex_enter(&ms->ms_lock);
        intr_flags = ms->ms_intr_flags;
        ms->ms_intr_flags = 0;

        /*
         * Copy data from the receive ring to the event layer.
         */
        get = ms->ms_rbget;
        while (get != ms->ms_rbput) {
                ring_data = ms->ms_rbuf[get];
                mutex_exit(&ms->ms_lock);
                get = (get + 1) & MS_RX_RING_MASK;

                /* low byte of ring_data is rr1 */
                c = (ring_data >> 8) & 0xff;

                if (ring_data & ZSRR1_DO)
                        intr_flags |= INTR_RX_OVERRUN;
                if (ring_data & (ZSRR1_FE | ZSRR1_PE)) {
                        log(LOG_ERR, "%s: input error (0x%x)\n",
                            device_xname(ms->ms_dev), ring_data);
                        c = -1; /* signal input error */
                }

                /* Pass this up to the "middle" layer. */
                ms_input(ms, c);
                mutex_enter(&ms->ms_lock);
        }
        mutex_exit(&ms->ms_lock);

        if (intr_flags & INTR_RX_OVERRUN) {
                log(LOG_ERR, "%s: input overrun\n",
                    device_xname(ms->ms_dev));
        }
        ms->ms_rbget = get;

        if (intr_flags & INTR_TX_EMPTY) {
                /*
                 * Transmit done.  (Not expected.)
                 */
                log(LOG_ERR, "%s: transmit interrupt?\n",
                    device_xname(ms->ms_dev));
        }

        if (intr_flags & INTR_ST_CHECK) {
                /*
                 * Status line change.  (Not expected.)
                 */
                log(LOG_ERR, "%s: status interrupt?\n",
                    device_xname(ms->ms_dev));
                mutex_enter(&ms->ms_lock);
                cs->cs_rr0_delta = 0;
                mutex_exit(&ms->ms_lock);
        }
}


static void
ms_trigger(struct zs_chanstate *cs, int onoff)
{
        /* for front connected one */
        if (onoff)
                cs->cs_preg[5] |= ZSWR5_RTS;
        else
                cs->cs_preg[5] &= ~ZSWR5_RTS;
        cs->cs_creg[5] = cs->cs_preg[5];
        zs_write_reg(cs, 5, cs->cs_preg[5]);

        /* for keyboard connected one */
        mfp_send_usart(onoff | 0x40);
}

/*
 * mouse timer interrupt.
 * called after system tick interrupt is done.
 */
static void
ms_modem(void *arg)
{
        struct ms_softc *ms = arg;

        if (!ms->ms_ready)
                return;

        mutex_enter(&ms->ms_lock);

        if (ms->ms_nodata++ > MS_TIMEOUT) {
                log(LOG_ERR, "%s: no data for %d secs. resetting.\n",
                    device_xname(ms->ms_dev), MS_TIMEOUT_SEC);
                ms->ms_byteno = -1;
                ms->ms_nodata = 0;
                ms->ms_rts = 0;
        }

        if (ms->ms_rts) {
                if (ms->ms_byteno == -1) {
                        /* start next sequence */
                        ms->ms_rts = 0;
                        ms_trigger(ms->ms_cs, ms->ms_rts);
                        ms->ms_byteno = 0;
                }
        } else {
                ms->ms_rts = 1;
                ms_trigger(ms->ms_cs, ms->ms_rts);
        }

        mutex_exit(&ms->ms_lock);
        callout_schedule(&ms->ms_modem_ch, MS_TICK);
}