root/sys/dev/hil/hil.c
/*      $OpenBSD: hil.c,v 1.29 2022/01/09 05:42:37 jsg Exp $    */
/*
 * Copyright (c) 2003, 2004, Miodrag Vallat.
 * 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.
 *
 * 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.
 *
 */

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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.
 *
 * from: Utah $Hdr: hil.c 1.38 92/01/21$
 *
 *      @(#)hil.c       8.2 (Berkeley) 1/12/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/ioctl.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/kthread.h>

#include <machine/autoconf.h>
#include <machine/bus.h>
#include <machine/cpu.h>

#include <dev/hil/hilreg.h>
#include <dev/hil/hilvar.h>
#include <dev/hil/hildevs.h>
#include <dev/hil/hildevs_data.h>

#include "hilkbd.h"

/*
 * splhigh is extremely conservative but insures atomic operation,
 * splvm (clock only interrupts) seems to be good enough in practice.
 */
#define splhil  splvm

struct cfdriver hil_cd = {
        NULL, "hil", DV_DULL
};

void    hilconfig(struct hil_softc *, u_int);
void    hilempty(struct hil_softc *);
int     hilsubmatch(struct device *, void *, void *);
void    hil_process_int(struct hil_softc *, u_int8_t, u_int8_t);
int     hil_process_poll(struct hil_softc *, u_int8_t, u_int8_t);
void    hil_thread(void *);
int     send_device_cmd(struct hil_softc *sc, u_int device, u_int cmd);
void    polloff(struct hil_softc *);
void    pollon(struct hil_softc *);

static int hilwait(struct hil_softc *);
static int hildatawait(struct hil_softc *);

#define hil_process_pending(sc) wakeup(&(sc)->sc_pending)

static __inline int
hilwait(struct hil_softc *sc)
{
        int cnt;

        for (cnt = 50000; cnt != 0; cnt--) {
                DELAY(1);
                if ((bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT) &
                    HIL_BUSY) == 0)
                        break;
        }

        return (cnt);
}

static __inline int
hildatawait(struct hil_softc *sc)
{
        int cnt;

        for (cnt = 50000; cnt != 0; cnt--) {
                DELAY(1);
                if ((bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT) &
                    HIL_DATA_RDY) != 0)
                        break;
        }

        return (cnt);
}

/*
 * Common HIL bus attachment
 */

void
hil_attach(struct hil_softc *sc, int *hil_is_console)
{
        printf("\n");

        /*
         * Initialize loop information
         */
        sc->sc_cmdending = 0;
        sc->sc_actdev = sc->sc_cmddev = 0;
        sc->sc_cmddone = 0;
        sc->sc_cmdbp = sc->sc_cmdbuf;
        sc->sc_pollbp = sc->sc_pollbuf;
        sc->sc_console = hil_is_console;
}

/*
 * HIL subdevice attachment
 */

int
hildevprint(void *aux, const char *pnp)
{
        struct hil_attach_args *ha = aux;

        if (pnp != NULL) {
                printf("\"%s\" at %s id %x",
                    ha->ha_descr, pnp, ha->ha_id);
        }
        printf(" code %d", ha->ha_code);
        if (pnp == NULL) {
                printf(": %s", ha->ha_descr);
        }

        return (UNCONF);
}

int
hilsubmatch(struct device *parent, void *vcf, void *aux)
{
        struct hil_attach_args *ha = aux;
        struct cfdata *cf = vcf;

        if (cf->cf_loc[0] != -1 &&
            cf->cf_loc[0] != ha->ha_code)
                return (0);

        return ((*cf->cf_attach->ca_match)(parent, vcf, aux));
}

void
hil_attach_deferred(void *v)
{
        struct hil_softc *sc = v;
        int tries;
        u_int8_t db;

        sc->sc_status = HIL_STATUS_BUSY;

        /*
         * Initialize the loop: reconfigure, don't report errors,
         * put keyboard in cooked mode, and enable autopolling.
         */
        db = LPC_RECONF | LPC_KBDCOOK | LPC_NOERROR | LPC_AUTOPOLL;
        send_hil_cmd(sc, HIL_WRITELPCTRL, &db, 1, NULL);

        /*
         * Delay one second for reconfiguration and then read the
         * data to clear the interrupt (if the loop reconfigured).
         */
        DELAY(1000000);
        if (bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT) &
            HIL_DATA_RDY) {
                db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
                DELAY(1);
        }

        /*
         * The HIL loop may have reconfigured.  If so we proceed on,
         * if not we loop a few times until a successful reconfiguration
         * is reported back to us. If the HIL loop is still lost after a
         * few seconds, give up.
         */
        for (tries = 10; tries != 0; tries--) {
                if (send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db) == 0) {
                        if (db & (LPS_CONFFAIL | LPS_CONFGOOD))
                                break;
                }

#ifdef HILDEBUG
                printf("%s: loop not ready, retrying...\n",
                    sc->sc_dev.dv_xname);
#endif

                DELAY(1000000);
        }

        if (tries == 0 || (db & LPS_CONFFAIL)) {
                printf("%s: no devices\n", sc->sc_dev.dv_xname);
                sc->sc_pending = 0;
                if (tries == 0)
                        return;
        }

        /*
         * Create asynchronous loop event handler thread.
         */
        if (kthread_create(hil_thread, sc, &sc->sc_thread,
            sc->sc_dev.dv_xname) != 0) {
                printf("%s: unable to create event thread\n",
                    sc->sc_dev.dv_xname);
                return;
        }

        /*
         * Enable loop interrupts.
         */
        send_hil_cmd(sc, HIL_INTON, NULL, 0, NULL);

        /*
         * Reconfigure if necessary
         */
        sc->sc_status = HIL_STATUS_READY;
        hil_process_pending(sc);
}

/*
 * Asynchronous event processing
 */

int
hil_intr(void *v)
{
        struct hil_softc *sc = v;
        u_int8_t c, stat;

        if (cold)
                return (0);

        stat = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT);

        /*
         * This should never happen if the interrupt comes from the
         * loop.
         */
        if ((stat & HIL_DATA_RDY) == 0)
                return (0);     /* not for us */

        c = bus_space_read_1(sc->sc_bst, sc->sc_bsh,
            HILP_DATA); /* clears interrupt */
        DELAY(1);

        hil_process_int(sc, stat, c);

        if (sc->sc_status != HIL_STATUS_BUSY)
                hil_process_pending(sc);

        return (1);
}

void
hil_process_int(struct hil_softc *sc, u_int8_t stat, u_int8_t c)
{
        struct hildev_softc *dev;

        switch ((stat >> HIL_SSHIFT) & HIL_SMASK) {
        case HIL_STATUS:
                if (c & HIL_ERROR) {
                        sc->sc_cmddone = 1;
                        switch (c) {
                        case HIL_RECONFIG:
                                sc->sc_pending = HIL_PENDING_RECONFIG;
                                break;
                        case HIL_UNPLUGGED:
                                sc->sc_pending = HIL_PENDING_UNPLUGGED;
                                break;
                        }
                        break;
                }
                if (c & HIL_COMMAND) {
                        if (c & HIL_POLLDATA) { /* End of data */
                                dev = sc->sc_devices[sc->sc_actdev];
                                if (dev != NULL && dev->sc_fn != NULL)
                                        dev->sc_fn(dev,
                                            sc->sc_pollbp - sc->sc_pollbuf,
                                            sc->sc_pollbuf);
                        } else {                /* End of command */
                                sc->sc_cmdending = 1;
                        }
                        sc->sc_actdev = 0;
                } else {
                        if (c & HIL_POLLDATA) { /* Start of polled data */
                                sc->sc_actdev = (c & HIL_DEVMASK);
                                sc->sc_pollbp = sc->sc_pollbuf;
                        } else {                /* Start of command */
                                if (sc->sc_cmddev == (c & HIL_DEVMASK)) {
                                        sc->sc_cmdbp = sc->sc_cmdbuf;
                                        sc->sc_actdev = 0;
                                }
                        }
                }
                break;
        case HIL_DATA:
                if (sc->sc_actdev != 0) /* Collecting poll data */
                        *sc->sc_pollbp++ = c;
                else {
                        if (sc->sc_cmddev != 0) {  /* Collecting cmd data */
                                if (sc->sc_cmdending) {
                                        sc->sc_cmddone = 1;
                                        sc->sc_cmdending = 0;
                                } else  
                                        *sc->sc_cmdbp++ = c;
                        }
                }
                break;
        }
}

/*
 * Same as above, but in polled mode: return data as it gets seen, instead
 * of buffering it.
 */
int
hil_process_poll(struct hil_softc *sc, u_int8_t stat, u_int8_t c)
{
        u_int8_t db;

        switch ((stat >> HIL_SSHIFT) & HIL_SMASK) {
        case HIL_STATUS:
                if (c & HIL_ERROR) {
                        sc->sc_cmddone = 1;
                        switch (c) {
                        case HIL_RECONFIG:
                                /*
                                 * Remember that a configuration event
                                 * occurred; it will be processed upon
                                 * leaving polled mode...
                                 */
                                sc->sc_pending = HIL_PENDING_RECONFIG;
                                /*
                                 * However, the keyboard will come back as
                                 * cooked, and we rely on it being in raw
                                 * mode. So, put it back in raw mode right
                                 * now.
                                 */
                                db = 0;
                                send_hil_cmd(sc, HIL_WRITEKBDSADR, &db,
                                    1, NULL);
                                break;
                        case HIL_UNPLUGGED:
                                /*
                                 * Remember that an unplugged event
                                 * occurred; it will be processed upon
                                 * leaving polled mode...
                                 */
                                sc->sc_pending = HIL_PENDING_UNPLUGGED;
                                break;
                        }
                        break;
                }
                if (c & HIL_COMMAND) {
                        if (!(c & HIL_POLLDATA)) {
                                /* End of command */
                                sc->sc_cmdending = 1;
                        }
                        sc->sc_actdev = 0;
                } else {
                        if (c & HIL_POLLDATA) {
                                /* Start of polled data */
                                sc->sc_actdev = (c & HIL_DEVMASK);
                                sc->sc_pollbp = sc->sc_pollbuf;
                        } else {
                                /* Start of command - should not happen */
                                if (sc->sc_cmddev == (c & HIL_DEVMASK)) {
                                        sc->sc_cmdbp = sc->sc_cmdbuf;
                                        sc->sc_actdev = 0;
                                }
                        }
                }
                break;
        case HIL_DATA:
                if (sc->sc_actdev != 0) /* Collecting poll data */
                        return 1;
                else {
                        if (sc->sc_cmddev != 0) {  /* Discarding cmd data */
                                if (sc->sc_cmdending) {
                                        sc->sc_cmddone = 1;
                                        sc->sc_cmdending = 0;
                                }
                        }
                }
                break;
        }

        return 0;
}

void
hil_thread(void *arg)
{
        struct hil_softc *sc = arg;
        int s;

        for (;;) {
                s = splhil();
                if (sc->sc_pending == 0) {
                        splx(s);
                        tsleep_nsec(&sc->sc_pending, PWAIT, "hil_event",
                            INFSLP);
                        continue;
                }

                switch (sc->sc_pending) {
                case HIL_PENDING_RECONFIG:
                        sc->sc_pending = 0;
                        hilconfig(sc, sc->sc_maxdev);
                        break;
                case HIL_PENDING_UNPLUGGED:
                        sc->sc_pending = 0;
                        hilempty(sc);
                        break;
                }
                splx(s);
        }
}

/*
 * Called after the loop has reconfigured.  Here we need to:
 *      - determine how many devices are on the loop
 *        (some may have been added or removed)
 *      - make sure all keyboards are in raw mode
 *
 * Note that our device state is now potentially invalid as
 * devices may no longer be where they were.  What we should
 * do here is either track where the devices went and move
 * state around accordingly...
 *
 * Note that it is necessary that we operate the loop with the keyboards
 * in raw mode: they won't cause the loop to generate an NMI if the
 * ``reset'' key combination is pressed, and we do not handle the hil
 * NMI interrupt...
 */
void
hilconfig(struct hil_softc *sc, u_int knowndevs)
{
        struct hil_attach_args ha;
        u_int8_t db;
        int id, s;

        s = splhil();

        /*
         * Determine how many devices are on the loop.
         */
        db = 0;
        send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db);
        sc->sc_maxdev = db & LPS_DEVMASK;
#ifdef HILDEBUG
        printf("%s: %d device(s)\n", sc->sc_dev.dv_xname, sc->sc_maxdev);
#endif

        /*
         * Put all keyboards in raw mode now.
         */
        db = 0;
        send_hil_cmd(sc, HIL_WRITEKBDSADR, &db, 1, NULL);

        /*
         * If the loop grew, attach new devices.
         */
        for (id = knowndevs + 1; id <= sc->sc_maxdev; id++) {
                int len;
                const struct hildevice *hd;
                
                if (send_device_cmd(sc, id, HIL_IDENTIFY) != 0) {
                        printf("%s: no answer from device %d\n",
                            sc->sc_dev.dv_xname, id);
                        continue;
                }

                len = sc->sc_cmdbp - sc->sc_cmdbuf;
                if (len == 0) {
#ifdef HILDEBUG
                        printf("%s: no device at code %d\n",
                            sc->sc_dev.dv_xname, id);
#endif
                        continue;
                }

                /* Identify and attach device */
                for (hd = hildevs; hd->minid >= 0; hd++)
                        if (sc->sc_cmdbuf[0] >= hd->minid &&
                            sc->sc_cmdbuf[0] <= hd->maxid) {

                        ha.ha_console = *sc->sc_console;
                        ha.ha_code = id;
                        ha.ha_type = hd->type;
                        ha.ha_descr = hd->descr;
                        ha.ha_infolen = len;
                        bcopy(sc->sc_cmdbuf, ha.ha_info, len);

                        sc->sc_devices[id] = (struct hildev_softc *)
                            config_found_sm(&sc->sc_dev, &ha, hildevprint,
                                hilsubmatch);

#if NHILKBD > 0
                        /*
                         * If we just attached a keyboard as console,
                         * console choice is not indeterminate anymore.
                         */
                        if (sc->sc_devices[id] != NULL &&
                            ha.ha_type == HIL_DEVICE_KEYBOARD &&
                            ha.ha_console != 0)
                                *sc->sc_console = 1;
#endif
                }
        }

        /*
         * Detach remaining devices, if the loop has shrunk.
         */
        for (id = sc->sc_maxdev + 1; id < NHILD; id++) {
                if (sc->sc_devices[id] != NULL)
                        config_detach((struct device *)sc->sc_devices[id],
                            DETACH_FORCE);
                sc->sc_devices[id] = NULL;
        }

        sc->sc_cmdbp = sc->sc_cmdbuf;

        splx(s);
}

/*
 * Called after the loop has been unplugged. We simply force detach of
 * all our children.
 */
void
hilempty(struct hil_softc *sc)
{
        u_int8_t db;
        int id, s;
        u_int oldmaxdev;

        s = splhil();

        /*
         * Wait for the loop to be stable.
         */
        for (;;) {
                if (send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db) == 0) {
                        if (db & (LPS_CONFFAIL | LPS_CONFGOOD))
                                break;
                } else {
                        db = LPS_CONFFAIL;
                        break;
                }
        }

        if (db & LPS_CONFFAIL) {
                sc->sc_maxdev = 0;
        } else {
                db = 0;
                send_hil_cmd(sc, HIL_READLPSTAT, NULL, 0, &db);
                oldmaxdev = sc->sc_maxdev;
                sc->sc_maxdev = db & LPS_DEVMASK;

                if (sc->sc_maxdev != 0) {
                        /*
                         * The loop was not unplugged after all, but its
                         * configuration has changed.
                         */
                        hilconfig(sc, oldmaxdev);
                        splx(s);
                        return;
                }
        }

        /*
         * Now detach all hil devices.
         */
        for (id = sc->sc_maxdev + 1; id < NHILD; id++) {
                if (sc->sc_devices[id] != NULL)
                        config_detach((struct device *)sc->sc_devices[id],
                            DETACH_FORCE);
                sc->sc_devices[id] = NULL;
        }

        sc->sc_cmdbp = sc->sc_cmdbuf;

        splx(s);
}

/*
 * Low level routines which actually talk to the 8042 chip.
 */

/*
 * Send a command to the 8042 with zero or more bytes of data.
 * If rdata is non-null, wait for and return a byte of data.
 */
int
send_hil_cmd(struct hil_softc *sc, u_int cmd, u_int8_t *data, u_int dlen,
    u_int8_t *rdata)
{
        u_int8_t status;
        int s;
        
        s = splhil();

        if (hilwait(sc) == 0) {
#ifdef HILDEBUG
                printf("%s: no answer from the loop\n", sc->sc_dev.dv_xname);
#endif
                splx(s);
                return (EBUSY);
        }

        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, cmd);
        while (dlen--) {
                hilwait(sc);
                bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, *data++);
                DELAY(1);
        }
        if (rdata) {
                do {
                        if (hildatawait(sc) == 0) {
#ifdef HILDEBUG
                                printf("%s: no answer from the loop\n",
                                    sc->sc_dev.dv_xname);
#endif
                                break;
                        }
                        status = bus_space_read_1(sc->sc_bst, sc->sc_bsh,
                            HILP_STAT);
                        *rdata = bus_space_read_1(sc->sc_bst, sc->sc_bsh,
                            HILP_DATA);
                        DELAY(1);
                } while (((status >> HIL_SSHIFT) & HIL_SMASK) != HIL_68K);
        }
        splx(s);
        return (0);
}

/*
 * Send a command to a device on the loop.
 * Since only one command can be active on the loop at any time,
 * we must ensure that we are not interrupted during this process.
 * Hence we mask interrupts to prevent potential access from most
 * interrupt routines and turn off auto-polling to disable the
 * internally generated poll commands.
 * Needs to be called at splhil().
 */
int
send_device_cmd(struct hil_softc *sc, u_int device, u_int cmd)
{
        u_int8_t status, c;
        int rc = 0;

        polloff(sc);

        sc->sc_cmdbp = sc->sc_cmdbuf;
        sc->sc_cmddev = device;

        if (hilwait(sc) == 0) {
#ifdef HILDEBUG
                printf("%s: no answer from device %d\n",
                    sc->sc_dev.dv_xname, device);
#endif
                rc = EBUSY;
                goto out;
        }

        /*
         * Transfer the command and device info to the chip
         */
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_STARTCMD);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, 8 + device);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, cmd);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, HIL_TIMEOUT);

        /*
         * Trigger the command and wait for completion
         */
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_TRIGGER);
        sc->sc_cmddone = 0;
        do {
                if (hildatawait(sc) == 0) {
#ifdef HILDEBUG
                        printf("%s: no answer from device %d\n",
                            sc->sc_dev.dv_xname, device);
#endif
                        rc = EBUSY;
                        break;
                }
                status = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT);
                c = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
                DELAY(1);
                hil_process_int(sc, status, c);
        } while (sc->sc_cmddone == 0);
out:
        sc->sc_cmddev = 0;

        pollon(sc);
        return (rc);
}

int
send_hildev_cmd(struct hildev_softc *dev, u_int cmd,
    u_int8_t *outbuf, u_int *outlen)
{
        struct hil_softc *sc = (struct hil_softc *)dev->sc_dev.dv_parent;
        int s, rc;
       
        s = splhil();

        if ((rc = send_device_cmd(sc, dev->sc_code, cmd)) == 0) {
                /*
                 * Return the command response in the buffer if necessary
                */
                if (outbuf != NULL && outlen != NULL) {
                        *outlen = min(*outlen, sc->sc_cmdbp - sc->sc_cmdbuf);
                        bcopy(sc->sc_cmdbuf, outbuf, *outlen);
                }
        }

        splx(s);
        return (rc);
}

/*
 * Turn auto-polling off and on.
 */
void
polloff(struct hil_softc *sc)
{
        u_int8_t db;

        if (hilwait(sc) == 0)
                return;

        /*
         * Turn off auto repeat
         */
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_SETARR);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, 0);

        /*
         * Turn off auto-polling
         */
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_READLPCTRL);
        hildatawait(sc);
        db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
        db &= ~LPC_AUTOPOLL;
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_WRITELPCTRL);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, db);

        /*
         * Must wait until polling is really stopped
         */
        do {    
                hilwait(sc);
                bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_READBUSY);
                hildatawait(sc);
                db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
        } while (db & BSY_LOOPBUSY);

        sc->sc_cmddone = 0;
        sc->sc_cmddev = 0;
}

void
pollon(struct hil_softc *sc)
{
        u_int8_t db;

        if (hilwait(sc) == 0)
                return;

        /*
         * Turn on auto polling
         */
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_READLPCTRL);
        hildatawait(sc);
        db = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
        db |= LPC_AUTOPOLL;
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_WRITELPCTRL);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, db);

        /*
         * Turn off auto repeat - we emulate this through wscons
         */
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_CMD, HIL_SETARR);
        hilwait(sc);
        bus_space_write_1(sc->sc_bst, sc->sc_bsh, HILP_DATA, 0);
        DELAY(1);
}

void
hil_set_poll(struct hil_softc *sc, int on)
{
        if (on) {
                pollon(sc);
        } else {
                hil_process_pending(sc);
                send_hil_cmd(sc, HIL_INTON, NULL, 0, NULL);
        }
}

int
hil_poll_data(struct hildev_softc *dev, u_int8_t *stat, u_int8_t *data)
{
        struct hil_softc *sc = (struct hil_softc *)dev->sc_dev.dv_parent;
        u_int8_t s, c;

        s = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_STAT);
        if ((s & HIL_DATA_RDY) == 0)
                return -1;

        c = bus_space_read_1(sc->sc_bst, sc->sc_bsh, HILP_DATA);
        DELAY(1);

        if (hil_process_poll(sc, s, c)) {
                /* Discard any data not for us */
                if (sc->sc_actdev == dev->sc_code) {
                        *stat = s;
                        *data = c;
                        return 0;
                }
        }

        return -1;
}