/*      $NetBSD: kbd_zs.c,v 1.24 2022/09/25 21:30:29 thorpej 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.
 *
 *      @(#)kbd.c       8.2 (Berkeley) 10/30/93
 */

/*
 * /dev/kbd lower layer for sun keyboard off a zs channel.
 * This driver uses kbdsun middle layer to hook up to /dev/kbd.
 */

/*
 * Zilog Z8530 Dual UART driver (keyboard interface)
 *
 * This is the 8530 portion of the driver that will be attached to
 * the "zsc" driver for a Sun keyboard.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kbd_zs.c,v 1.24 2022/09/25 21:30:29 thorpej Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/signal.h>
#include <sys/signalvar.h>
#include <sys/time.h>
#include <sys/select.h>
#include <sys/syslog.h>

#include <dev/ic/z8530reg.h>
#include <machine/z8530var.h>
#include <dev/sun/vuid_event.h>
#include <dev/sun/event_var.h>
#include <dev/sun/kbd_reg.h>
#include <dev/sun/kbd_xlate.h>
#include <dev/sun/kbdvar.h>
#include <dev/sun/kbdsunvar.h>

#if NWSKBD > 0
void kbd_wskbd_attach(struct kbd_softc *k, int isconsole);
#endif

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

static void kbd_zs_rxint(struct zs_chanstate *);
static void kbd_zs_stint(struct zs_chanstate *, int);
static void kbd_zs_txint(struct zs_chanstate *);
static void kbd_zs_softint(struct zs_chanstate *);

struct zsops zsops_kbd = {
        kbd_zs_rxint,   /* receive char available */
        kbd_zs_stint,   /* external/status */
        kbd_zs_txint,   /* xmit buffer empty */
        kbd_zs_softint, /* process software interrupt */
};

static int      kbd_zs_match(device_t, cfdata_t, void *);
static void     kbd_zs_attach(device_t, device_t, void *);
static void     kbd_zs_write_data(struct kbd_sun_softc *, int);

CFATTACH_DECL_NEW(kbd_zs, sizeof(struct kbd_sun_softc),
    kbd_zs_match, kbd_zs_attach, NULL, NULL);

/* Fall-back baud rate */
int     kbd_zs_bps = KBD_DEFAULT_BPS;

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

        /* Exact match required for keyboard. */
        if (cf->cf_loc[ZSCCF_CHANNEL] == args->channel)
                return 2;

        return 0;
}

void
kbd_zs_attach(device_t parent, device_t self, void *aux)
{
        struct kbd_sun_softc *k = device_private(self);
        struct zsc_softc *zsc = device_private(parent);
        struct zsc_attach_args *args = aux;
        struct zs_chanstate *cs;
        int channel;
        int reset, s;
        int bps;

        k->k_kbd.k_dev = self;

        /* provide upper layer with a link to the middle layer */
        k->k_kbd.k_ops = &kbd_ops_sun;

        /* provide middle layer with a link to the lower layer (i.e. us) */
        channel = args->channel;
        cs = zsc->zsc_cs[channel];
        cs->cs_private = k;
        cs->cs_ops = &zsops_kbd;
        k->k_cs = cs;
        k->k_write_data = kbd_zs_write_data;

        if ((bps = cs->cs_defspeed) == 0)
                bps = kbd_zs_bps;

        aprint_normal(": baud rate %d", bps);

        if ((args->hwflags & ZS_HWFLAG_CONSOLE_INPUT) != 0) {
                /*
                 * Hookup ourselves as the console input channel
                 */
                struct cons_channel *cc = kbd_cc_alloc(&k->k_kbd);

                if (cc == NULL)
                        return;

                cons_attach_input(cc, args->consdev);
                k->k_kbd.k_isconsole = 1;
                aprint_normal(" (console input)");
        }
        aprint_normal("\n");

        /* Initialize the speed, etc. */
        s = splzs();
        if (k->k_kbd.k_isconsole == 0) {
                /* Not the console; may need reset. */
                reset = (channel == 0) ?
                    ZSWR9_A_RESET : ZSWR9_B_RESET;
                zs_write_reg(cs, 9, reset);
        }
        /* These are OK as set by zscc: WR3, WR4, WR5 */
        /* We don't care about status interrupts. */
        cs->cs_preg[1] = ZSWR1_RIE | ZSWR1_TIE;
        (void) zs_set_speed(cs, bps);
        zs_loadchannelregs(cs);
        splx(s);

        /* Do this before any calls to kbd_rint(). */
        kbd_xlate_init(&k->k_kbd.k_state);

        /* Magic sequence. */
        k->k_magic1 = KBD_L1;
        k->k_magic2 = KBD_A;
#if NWSKBD > 0
        kbd_wskbd_attach(&k->k_kbd, k->k_kbd.k_isconsole);
#endif
}

/*
 * used by kbd_sun_start_tx();
 */
void
kbd_zs_write_data(struct kbd_sun_softc *k, int c)
{
        int s;

        /* Need splzs to avoid interruption of the delay. */
        s = splzs();
        zs_write_data(k->k_cs, c);
        splx(s);
}

static void
kbd_zs_rxint(struct zs_chanstate *cs)
{
        struct kbd_sun_softc *k;
        int put, put_next;
        uint8_t c, rr1;

        k = cs->cs_private;
        put = k->k_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);
        }

        /*
         * Check NOW for a console abort sequence, so that we can
         * abort even when interrupts are locking up the machine.
         */
        if (k->k_magic1_down) {
                /* The last keycode was "MAGIC1" down. */
                k->k_magic1_down = 0;
                if (c == k->k_magic2) {
                        /* Magic "L1-A" sequence; enter debugger. */
                        if (k->k_kbd.k_isconsole) {
                                zs_abort(cs);
                                /* Debugger done.  Fake L1-up to finish it. */
                                c = k->k_magic1 | KBD_UP;
                        } else {
                                printf("%s: magic sequence, but not console\n",
                                    device_xname(k->k_kbd.k_dev));
                        }
                }
        }
        if (c == k->k_magic1) {
                k->k_magic1_down = 1;
        }

        k->k_rbuf[put] = (c << 8) | rr1;
        put_next = (put + 1) & KBD_RX_RING_MASK;

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

        /* Done reading. */
        k->k_rbput = put;

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


static void
kbd_zs_txint(struct zs_chanstate *cs)
{
        struct kbd_sun_softc *k;

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


static void
kbd_zs_stint(struct zs_chanstate *cs, int force)
{
        struct kbd_sun_softc *k;
        uint8_t rr0;

        k = cs->cs_private;

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

#if 0
        if (rr0 & ZSRR0_BREAK) {
                /* Keyboard unplugged? */
                zs_abort(cs);
                return;
        }
#endif

        /*
         * 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;
        k->k_intr_flags |= INTR_ST_CHECK;

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

/*
 * Get input from the receive ring and pass it on.
 * Note: this is called at splsoftclock()
 */
static void
kbd_zs_softint(struct zs_chanstate *cs)
{
        struct kbd_sun_softc *k;
        int get, c, s;
        int intr_flags;
        uint16_t ring_data;

        k = cs->cs_private;

        /* Atomically get and clear flags. */
        s = splzs();
        intr_flags = k->k_intr_flags;
        k->k_intr_flags = 0;

        /* Now lower to spltty for the rest. */
        (void)spltty();

        /*
         * Copy data from the receive ring to the event layer.
         */
        get = k->k_rbget;
        while (get != k->k_rbput) {
                ring_data = k->k_rbuf[get];
                get = (get + 1) & KBD_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)) {
                        /*
                         * After garbage, flush pending input, and
                         * send a reset to resync key translation.
                         */
                        log(LOG_ERR, "%s: input error (0x%x)\n",
                            device_xname(k->k_kbd.k_dev), ring_data);
                        get = k->k_rbput; /* flush */
                        goto send_reset;
                }

                /* Pass this up to the "middle" layer. */
                kbd_sun_input(k, c);
        }
        if (intr_flags & INTR_RX_OVERRUN) {
                log(LOG_ERR, "%s: input overrun\n",
                    device_xname(k->k_kbd.k_dev));
        send_reset:
                /* Send a reset to resync translation. */
                kbd_sun_output(k, KBD_CMD_RESET);
                kbd_sun_start_tx(k);
        }
        k->k_rbget = get;

        if (intr_flags & INTR_TX_EMPTY) {
                /*
                 * Transmit done.  Try to send more, or
                 * clear busy and wakeup drain waiters.
                 */
                k->k_txflags &= ~K_TXBUSY;
                kbd_sun_start_tx(k);
        }

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

        splx(s);
}