Fix UTIME_OMIT handling

[dragonfly.git] / sys / dev / misc / kbd / atkbdc.c

/*
 * (MPSAFE)
 *
 * Copyright (c) 1996-1999
 * Kazutaka YOKOTA (yokota@zodiac.mech.utsunomiya-u.ac.jp)
 * 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 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 AUTHOR 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.
 *
 * $FreeBSD: src/sys/dev/kbd/atkbdc.c,v 1.5.2.2 2002/03/31 11:02:02 murray Exp $
 * from kbdio.c,v 1.13 1998/09/25 11:55:46 yokota Exp
 */

#include "opt_kbd.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kbio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/syslog.h>

#include <machine/clock.h>

#include <bus/isa/isareg.h>

#include "atkbdcreg.h"
#include "kbdreg.h"
#include "use_atkbdc.h"

/* constants */

#define MAXKBDC MAX(NATKBDC, 1) /* XXX */

/* macros */

#ifndef MAX
#define MAX(x, y) ((x) > (y) ? (x) : (y))
#endif

#define nextq(i) (((i) + 1) % KBDQ_BUFSIZE)
#define availq(q) ((q)->head != (q)->tail)
#if KBDIO_DEBUG >= 2
#define emptyq(q) ((q)->tail = (q)->head = (q)->qcount = 0)
#else
#define emptyq(q) ((q)->tail = (q)->head = 0)
#endif

#define read_data(k) (bus_space_read_1((k)->iot, (k)->ioh0, 0))
#define read_status(k) (bus_space_read_1((k)->iot, (k)->ioh1, 0))
#define write_data(k, d) (bus_space_write_1((k)->iot, (k)->ioh0, 0, (d)))
#define write_command(k, d) (bus_space_write_1((k)->iot, (k)->ioh1, 0, (d)))

/* local variables */

/*
 * We always need at least one copy of the kbdc_softc struct for the
 * low-level console.  As the low-level console accesses the keyboard
 * controller before kbdc, and all other devices, is probed, we
 * statically allocate one entry. XXX
 */
static atkbdc_softc_t default_kbdc;
static atkbdc_softc_t *atkbdc_softc[MAXKBDC] = { &default_kbdc };

static int verbose = KBDIO_DEBUG;

/* function prototypes */

static int atkbdc_setup(atkbdc_softc_t *sc, bus_space_tag_t tag,
    bus_space_handle_t h0, bus_space_handle_t h1);
static int addq(kbdkqueue *q, int c);
static int removeq(kbdkqueue *q);
static int wait_while_controller_busy(atkbdc_softc_t *kbdc);
static int wait_for_data(atkbdc_softc_t *kbdc);
static int wait_for_kbd_data(atkbdc_softc_t *kbdc);
static int wait_for_kbd_ack(atkbdc_softc_t *kbdc);
static int wait_for_aux_data(atkbdc_softc_t *kbdc);
static int wait_for_aux_ack(atkbdc_softc_t *kbdc);

struct atkbdc_quirks {
        const char *bios_vendor;
        const char *maker;
        const char *product;
        const char *version;
        int quirk;
};

/* Old chromebooks running coreboot with i8042 emulation quirks */
#define CHROMEBOOK_WORKAROUND                                         \
        (KBDC_QUIRK_KEEP_ACTIVATED | KBDC_QUIRK_IGNORE_PROBE_RESULT | \
            KBDC_QUIRK_RESET_AFTER_PROBE | KBDC_QUIRK_SETLEDS_ON_INIT)

static struct atkbdc_quirks quirks[] = {
        /*
         * Older chromebooks running coreboot have an EC that imperfectly
         * emulates i8042 w/o fixes to its firmware.  Since we can't probe for
         * the problem, include all chromebooks by matching 'Google_' in the
         * bios version string or a maker of either 'Google' or 'GOOGLE'. This
         * is imperfect, but catches all chromebooks while omitting non-Google
         * systems from System76 and Purism.
         */
        { "coreboot", NULL, NULL, "Google_", CHROMEBOOK_WORKAROUND },
        { "coreboot", "GOOGLE", NULL, NULL, CHROMEBOOK_WORKAROUND },
        { "coreboot", "Google", NULL, NULL, CHROMEBOOK_WORKAROUND },
        /* KBDC hangs on Lenovo X120e and X121e after disabling AUX MUX */
        { NULL, "LENOVO", NULL, NULL, KBDC_QUIRK_DISABLE_MUX_PROBE },
};

#define QUIRK_STR_EQUAL(s1, s2) \
        (s1 == NULL || (s2 != NULL && strcmp(s1, s2) == 0))
#define QUIRK_STR_MATCH(s1, s2) \
        (s1 == NULL || (s2 != NULL && strncmp(s1, s2, strlen(s1)) == 0))

static int
atkbdc_getquirks(void)
{
        int i;
        char *bios_vendor = kgetenv("smbios.bios.vendor");
        char *maker = kgetenv("smbios.system.maker");
        char *product = kgetenv("smbios.system.product");
        char *version = kgetenv("smbios.bios.version");
        char *reldate = kgetenv("smbios.bios.reldate");

        for (i = 0; i < nitems(quirks); i++)
                if (QUIRK_STR_EQUAL(quirks[i].bios_vendor, bios_vendor) &&
                    QUIRK_STR_EQUAL(quirks[i].maker, maker) &&
                    QUIRK_STR_EQUAL(quirks[i].product, product) &&
                    QUIRK_STR_MATCH(quirks[i].version, version))
                        return (quirks[i].quirk);
        /*
         * Some Chromebooks don't conform to the google comment above so do the
         * Chromebook workaround for all <= 2018 coreboot systems that have a
         * 'blank' version.  At least one Acer "Peppy" chromebook has this
         * issue, with a reldate of 08/13/2014.
         */
        if (QUIRK_STR_EQUAL("coreboot", bios_vendor) &&
            (version != NULL && *version == ' ') &&
            (reldate != NULL && strlen(reldate) >= 10 &&
                strcmp(reldate + 6, "2018") <= 0))
                return (CHROMEBOOK_WORKAROUND);

        return (0);
}

atkbdc_softc_t *
atkbdc_get_softc(int unit)
{
        atkbdc_softc_t *sc;

        if (unit >= nitems(atkbdc_softc))
                return NULL;
        sc = atkbdc_softc[unit];
        if (sc == NULL) {
                sc = kmalloc(sizeof(*sc), M_DEVBUF, M_WAITOK | M_ZERO);
                atkbdc_softc[unit] = sc;
        }
        return sc;
}

int
atkbdc_probe_unit(int unit, struct resource *port0, struct resource *port1)
{
        if (rman_get_start(port0) <= 0)
                return ENXIO;
        if (rman_get_start(port1) <= 0)
                return ENXIO;
        return 0;
}

int
atkbdc_attach_unit(int unit, atkbdc_softc_t *sc, struct resource *port0,
    struct resource *port1)
{
        return atkbdc_setup(sc, rman_get_bustag(port0),
            rman_get_bushandle(port0), rman_get_bushandle(port1));
}

extern int acpi_fadt_8042_nolegacy;
int kicked_by_syscons = 0;

static void
atkbdc_fadt_done(void)
{
        if (kicked_by_syscons) {
                /*
                 * Configuring all keyboards is fine, because only atkbd
                 * really does something here, anyway.
                 */
                kbd_configure(KB_CONF_PROBE_ONLY);
        }
}

/* After fadt_probe in platform/pc64/acpica/acpi_fadt.c. */
SYSINIT(atkbdc_kick, SI_BOOT2_PRESMP, SI_ORDER_THIRD, atkbdc_fadt_done, 0);

/* the backdoor to the keyboard controller! XXX */
int
atkbdc_configure(void)
{
        bus_space_tag_t tag;
        bus_space_handle_t h0;
        bus_space_handle_t h1;
        int port0;
        int port1;
#if defined(__x86_64__)
        int i;
#endif

        kicked_by_syscons = 1;
        if (acpi_fadt_8042_nolegacy != 0)
                return ENXIO;

        port0 = IO_KBD;
        resource_int_value("atkbdc", 0, "port", &port0);
        port1 = IO_KBD + KBD_STATUS_PORT;
#if 0
        resource_int_value("atkbdc", 0, "port", &port0);
#endif

        /* XXX: tag should be passed from the caller */
#if defined(__x86_64__)
        tag = X86_64_BUS_SPACE_IO;
#else
        tag = 0; /* XXX */
#endif

#if 0 /* notyet */
        bus_space_map(tag, port0, IO_KBDSIZE, 0, &h0);
        bus_space_map(tag, port1, IO_KBDSIZE, 0, &h1);
#else
        h0 = (bus_space_handle_t)port0;
        h1 = (bus_space_handle_t)port1;
#endif

#if defined(__x86_64__)
        /*
         * Check if we really have AT keyboard controller. Poll status
         * register until we get "all clear" indication. If no such
         * indication comes, it probably means that there is no AT
         * keyboard controller present. Give up in such case. Check relies
         * on the fact that reading from non-existing in/out port returns
         * 0xff on i386. May or may not be true on other platforms.
         */
        for (i = 65536; i != 0; --i) {
                if ((bus_space_read_1(tag, h1, 0) & 0x2) == 0)
                        break;
                DELAY(16);
        }
        if (i == 0)
                return ENXIO;
#endif

        return atkbdc_setup(atkbdc_softc[0], tag, h0, h1);
}

static int
atkbdc_setup(atkbdc_softc_t *sc, bus_space_tag_t tag, bus_space_handle_t h0,
    bus_space_handle_t h1)
{
        u_int64_t tscval[3], read_delay;
        register_t flags;

        if (sc->ioh0 == 0) { /* XXX */
                sc->command_byte = -1;
                sc->command_mask = 0;
                sc->lock = FALSE;
                sc->kbd.head = sc->kbd.tail = 0;
                sc->aux.head = sc->aux.tail = 0;
                sc->aux_mux_enabled = FALSE;
#if KBDIO_DEBUG >= 2
                sc->kbd.call_count = 0;
                sc->kbd.qcount = sc->kbd.max_qcount = 0;
                sc->aux.call_count = 0;
                sc->aux.qcount = sc->aux.max_qcount = 0;
#endif
        }
        sc->iot = tag;
        sc->ioh0 = h0;
        sc->ioh1 = h1;
        /*
         * On certain chipsets AT keyboard controller isn't present and is
         * emulated by BIOS using SMI interrupt. On those chipsets reading
         * from the status port may be thousand times slower than usually.
         * Sometimes this emilation is not working properly resulting in
         * commands timing our and since we assume that inb() operation
         * takes very little time to complete we need to adjust number of
         * retries to keep waiting time within a designed limits (100ms).
         * Measure time it takes to make read_status() call and adjust
         * number of retries accordingly.
         */
        flags = intr_disable();
        tscval[0] = rdtsc();
        read_status(sc);
        tscval[1] = rdtsc();
        DELAY(1000);
        tscval[2] = rdtsc();
        intr_restore(flags);
        read_delay = tscval[1] - tscval[0];
        read_delay /= (tscval[2] - tscval[1]) / 1000;
        sc->retry = 100000 / ((KBDD_DELAYTIME * 2) + read_delay);

        sc->quirks = atkbdc_getquirks();

        return 0;
}

/* open a keyboard controller */
KBDC
atkbdc_open(int unit)
{
        if (unit <= 0)
                unit = 0;
        if (unit >= MAXKBDC)
                return NULL;
        if ((atkbdc_softc[unit]->port0 != NULL) ||
            (atkbdc_softc[unit]->ioh0 != 0)) /* XXX */
                return (KBDC)atkbdc_softc[unit];
        return NULL;
}

/*
 * I/O access arbitration in `kbdio'
 *
 * The `kbdio' module uses a simplistic convention to arbitrate
 * I/O access to the controller/keyboard/mouse. The convention requires
 * close cooperation of the calling device driver.
 *
 * The device drivers which utilize the `kbdio' module are assumed to
 * have the following set of routines.
 *    a. An interrupt handler (the bottom half of the driver).
 *    b. Timeout routines which may briefly poll the keyboard controller.
 *    c. Routines outside interrupt context (the top half of the driver).
 * They should follow the rules below:
 *    1. The interrupt handler may assume that it always has full access
 *       to the controller/keyboard/mouse.
 *    2. The other routines must issue `spltty()' if they wish to
 *       prevent the interrupt handler from accessing
 *       the controller/keyboard/mouse.
 *    3. The timeout routines and the top half routines of the device driver
 *       arbitrate I/O access by observing the lock flag in `kbdio'.
 *       The flag is manipulated via `kbdc_lock()'; when one wants to
 *       perform I/O, call `kbdc_lock(kbdc, TRUE)' and proceed only if
 *       the call returns with TRUE. Otherwise the caller must back off.
 *       Call `kbdc_lock(kbdc, FALSE)' when necessary I/O operaion
 *       is finished. This mechanism does not prevent the interrupt
 *       handler from being invoked at any time and carrying out I/O.
 *       Therefore, `spltty()' must be strategically placed in the device
 *       driver code. Also note that the timeout routine may interrupt
 *       `kbdc_lock()' called by the top half of the driver, but this
 *       interruption is OK so long as the timeout routine observes
 *       rule 4 below.
 *    4. The interrupt and timeout routines should not extend I/O operation
 *       across more than one interrupt or timeout; they must complete any
 *       necessary I/O operation within one invocation of the routine.
 *       This means that if the timeout routine acquires the lock flag,
 *       it must reset the flag to FALSE before it returns.
 */

/* set/reset polling lock */
int
kbdc_lock(KBDC p, int lock)
{
        int prevlock;

        prevlock = p->lock;
        p->lock = lock;

        return (prevlock != lock);
}

/* check if any data is waiting to be processed */
int
kbdc_data_ready(KBDC p)
{
        return (availq(&p->kbd) || availq(&p->aux) ||
            (read_status(p) & KBDS_ANY_BUFFER_FULL));
}

/* queuing functions */

static int
addq(kbdkqueue *q, int c)
{
        if (nextq(q->tail) != q->head) {
                q->q[q->tail] = c;
                q->tail = nextq(q->tail);
#if KBDIO_DEBUG >= 2
                ++q->call_count;
                ++q->qcount;
                if (q->qcount > q->max_qcount)
                        q->max_qcount = q->qcount;
#endif
                return TRUE;
        }
        return FALSE;
}

static int
removeq(kbdkqueue *q)
{
        int c;

        if (q->tail != q->head) {
                c = q->q[q->head];
                q->head = nextq(q->head);
#if KBDIO_DEBUG >= 2
                --q->qcount;
#endif
                return c;
        }
        return -1;
}

/*
 * device I/O routines
 */
static int
wait_while_controller_busy(struct atkbdc_softc *kbdc)
{
        /* CPU will stay inside the loop for 100msec at most */
        TOTALDELAY retry = { .us = 70000, .last_clock = 0 }; /* 70ms */
        int f;
        unsigned char c;

        while ((f = read_status(kbdc)) & KBDS_INPUT_BUFFER_FULL) {
                if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        c = read_data(kbdc);
                        addq(&kbdc->kbd, c);
                } else if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        c = read_data(kbdc);
                        addq(&kbdc->aux, c);
                }
                DELAY(KBDC_DELAYTIME);
                if (CHECKTIMEOUT(&retry))
                        return FALSE;
        }
        return TRUE;
}

/*
 * wait for any data; whether it's from the controller,
 * the keyboard, or the aux device.
 */
static int
wait_for_data(struct atkbdc_softc *kbdc)
{
        /* CPU will stay inside the loop for 200msec at most */
        TOTALDELAY retry = { 200000, 0 }; /* 200ms */
        int f;

        while ((f = read_status(kbdc) & KBDS_ANY_BUFFER_FULL) == 0) {
                DELAY(KBDC_DELAYTIME);
                if (CHECKTIMEOUT(&retry))
                        return 0;
        }
        DELAY(KBDD_DELAYTIME);
        return f;
}

/* wait for data from the keyboard */
static int
wait_for_kbd_data(struct atkbdc_softc *kbdc)
{
        /* CPU will stay inside the loop for 200msec at most */
        TOTALDELAY retry = { 200000, 0 }; /* 200ms */
        int f;
        unsigned char c;

        while ((f = read_status(kbdc) & KBDS_BUFFER_FULL) !=
            KBDS_KBD_BUFFER_FULL) {
                if (f == KBDS_AUX_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        c = read_data(kbdc);
                        addq(&kbdc->aux, c);
                }
                DELAY(KBDC_DELAYTIME);
                if (CHECKTIMEOUT(&retry))
                        return 0;
        }
        DELAY(KBDD_DELAYTIME);
        return f;
}

/*
 * wait for an ACK(FAh), RESEND(FEh), or RESET_FAIL(FCh) from the keyboard.
 * queue anything else.
 */
static int
wait_for_kbd_ack(struct atkbdc_softc *kbdc)
{
        /* CPU will stay inside the loop for 200msec at most */
        TOTALDELAY retry = { 200000, 0 }; /* 200ms */
        int f;
        int b;

        while (CHECKTIMEOUT(&retry) == 0) {
                if ((f = read_status(kbdc)) & KBDS_ANY_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        b = read_data(kbdc);
                        if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
                                if ((b == KBD_ACK) || (b == KBD_RESEND) ||
                                    (b == KBD_RESET_FAIL))
                                        return b;
                                addq(&kbdc->kbd, b);
                        } else if ((f & KBDS_BUFFER_FULL) ==
                            KBDS_AUX_BUFFER_FULL) {
                                addq(&kbdc->aux, b);
                        }
                }
                DELAY(KBDC_DELAYTIME);
        }
        return -1;
}

/* wait for data from the aux device */
static int
wait_for_aux_data(struct atkbdc_softc *kbdc)
{
        /* CPU will stay inside the loop for 200msec at most */
        TOTALDELAY retry = { 200000, 0 }; /* 200ms */
        int f;
        unsigned char b;

        while ((f = read_status(kbdc) & KBDS_BUFFER_FULL) !=
            KBDS_AUX_BUFFER_FULL) {
                if (f == KBDS_KBD_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        b = read_data(kbdc);
                        addq(&kbdc->kbd, b);
                }
                DELAY(KBDC_DELAYTIME);
                if (CHECKTIMEOUT(&retry))
                        return 0;
        }
        DELAY(KBDD_DELAYTIME);
        return f;
}

/*
 * wait for an ACK(FAh), RESEND(FEh), or RESET_FAIL(FCh) from the aux device.
 * queue anything else.
 */
static int
wait_for_aux_ack(struct atkbdc_softc *kbdc)
{
        /* CPU will stay inside the loop for 200msec at most */
        TOTALDELAY retry = { 200000, 0 }; /* 200ms */
        int f;
        int b;

        while (CHECKTIMEOUT(&retry) == 0) {
                if ((f = read_status(kbdc)) & KBDS_ANY_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        b = read_data(kbdc);
                        if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
                                if ((b == PSM_ACK) || (b == PSM_RESEND) ||
                                    (b == PSM_RESET_FAIL))
                                        return b;
                                addq(&kbdc->aux, b);
                        } else if ((f & KBDS_BUFFER_FULL) ==
                            KBDS_KBD_BUFFER_FULL) {
                                addq(&kbdc->kbd, b);
                        }
                }
                DELAY(KBDC_DELAYTIME);
        }
        return -1;
}

/*
 * Returns read-back data or -1 on failure
 */
int
write_controller_w1r1(KBDC p, int c, int d)
{
        if (!write_controller_command(p, c))
                return (-1);
        if (!write_controller_data(p, d))
                return (-1);
        return (read_controller_data(p));
}

/* write a one byte command to the controller */
int
write_controller_command(KBDC p, int c)
{
        if (!wait_while_controller_busy(p))
                return FALSE;
        write_command(p, c);
        return TRUE;
}

/* write a one byte data to the controller */
int
write_controller_data(KBDC p, int c)
{
        if (!wait_while_controller_busy(p))
                return FALSE;
        write_data(p, c);
        return TRUE;
}

/* write a one byte keyboard command */
int
write_kbd_command(KBDC p, int c)
{
        if (!wait_while_controller_busy(p))
                return FALSE;
        write_data(p, c);
        return TRUE;
}

/* write a one byte auxiliary device command */
int
write_aux_command(KBDC p, int c)
{
        int f;

        f = aux_mux_is_enabled(p) ? KBDC_WRITE_TO_AUX_MUX + p->aux_mux_port :
                                    KBDC_WRITE_TO_AUX;

        if (!write_controller_command(p, f))
                return FALSE;
        return write_controller_data(p, c);
}

/* send a command to the keyboard and wait for ACK */
int
send_kbd_command(KBDC p, int c)
{
        int retry = KBD_MAXRETRY;
        int res = -1;

        while (retry-- > 0) {
                if (!write_kbd_command(p, c))
                        continue;
                res = wait_for_kbd_ack(p);
                if (res == KBD_ACK)
                        break;
        }
        return res;
}

/* send a command to the auxiliary device and wait for ACK */
int
send_aux_command(KBDC p, int c)
{
        int retry = KBD_MAXRETRY;
        int res = -1;

        while (retry-- > 0) {
                if (!write_aux_command(p, c))
                        continue;
                /*
                 * FIXME: XXX
                 * The aux device may have already sent one or two bytes of
                 * status data, when a command is received. It will immediately
                 * stop data transmission, thus, leaving an incomplete data
                 * packet in our buffer. We have to discard any unprocessed
                 * data in order to remove such packets. Well, we may remove
                 * unprocessed, but necessary data byte as well...
                 */
                emptyq(&p->aux);
                res = wait_for_aux_ack(p);
                if (res == PSM_ACK)
                        break;
        }
        return res;
}

/* send a command and a data to the keyboard, wait for ACKs */
int
send_kbd_command_and_data(KBDC p, int c, int d)
{
        int retry;
        int res = -1;

        for (retry = KBD_MAXRETRY; retry > 0; --retry) {
                if (!write_kbd_command(p, c))
                        continue;
                res = wait_for_kbd_ack(p);
                if (res == KBD_ACK)
                        break;
                else if (res != KBD_RESEND)
                        return res;
        }
        if (retry <= 0)
                return res;

        for (retry = KBD_MAXRETRY, res = -1; retry > 0; --retry) {
                if (!write_kbd_command(p, d))
                        continue;
                res = wait_for_kbd_ack(p);
                if (res != KBD_RESEND)
                        break;
        }
        return res;
}

/* send a command and a data to the auxiliary device, wait for ACKs */
int
send_aux_command_and_data(KBDC p, int c, int d)
{
        int retry;
        int res = -1;

        for (retry = KBD_MAXRETRY; retry > 0; --retry) {
                if (!write_aux_command(p, c))
                        continue;
                emptyq(&p->aux);
                res = wait_for_aux_ack(p);
                if (res == PSM_ACK)
                        break;
                else if (res != PSM_RESEND)
                        return res;
        }
        if (retry <= 0)
                return res;

        for (retry = KBD_MAXRETRY, res = -1; retry > 0; --retry) {
                if (!write_aux_command(p, d))
                        continue;
                res = wait_for_aux_ack(p);
                if (res != PSM_RESEND)
                        break;
        }
        return res;
}

/*
 * read one byte from any source; whether from the controller,
 * the keyboard, or the aux device
 */
int
read_controller_data(KBDC p)
{
        if (availq(&p->kbd))
                return removeq(&p->kbd);
        if (availq(&p->aux))
                return removeq(&p->aux);
        if (!wait_for_data(p))
                return -1; /* timeout */
        return read_data(p);
}

#if KBDIO_DEBUG >= 2
static int call = 0;
#endif

/* read one byte from the keyboard */
int
read_kbd_data(KBDC p)
{
        unsigned char b;

#if KBDIO_DEBUG >= 2
        if (++call > 2000) {
                call = 0;
                log(LOG_DEBUG,
                    "kbdc: kbd q: %d calls, max %d chars, "
                    "aux q: %d calls, max %d chars\n",
                    p->kbd.call_count, p->kbd.max_qcount, p->aux.call_count,
                    p->aux.max_qcount);
        }
#endif

        if (availq(&p->kbd))
                return removeq(&p->kbd);
        if (!wait_for_kbd_data(p))
                return -1; /* timeout */
        b = read_data(p);
        return b;
}

/* read one byte from the keyboard, but return immediately if
 * no data is waiting
 */
int
read_kbd_data_no_wait(KBDC p)
{
        int f;
        unsigned char b;

#if KBDIO_DEBUG >= 2
        if (++call > 2000) {
                call = 0;
                log(LOG_DEBUG,
                    "kbdc: kbd q: %d calls, max %d chars, "
                    "aux q: %d calls, max %d chars\n",
                    p->kbd.call_count, p->kbd.max_qcount, p->aux.call_count,
                    p->aux.max_qcount);
        }
#endif

        if (availq(&p->kbd))
                return removeq(&p->kbd);
        f = read_status(p) & KBDS_BUFFER_FULL;
        while (f == KBDS_AUX_BUFFER_FULL) {
                DELAY(KBDD_DELAYTIME);
                b = read_data(p);
                addq(&p->aux, b);
                f = read_status(p) & KBDS_BUFFER_FULL;
        }
        if (f == KBDS_KBD_BUFFER_FULL) {
                DELAY(KBDD_DELAYTIME);
                b = read_data(p);
                return (int)b;
        }
        return -1; /* no data */
}

/* read one byte from the aux device */
int
read_aux_data(KBDC p)
{
        unsigned char b;
        if (availq(&p->aux))
                return removeq(&p->aux);
        if (!wait_for_aux_data(p))
                return -1; /* timeout */
        b = read_data(p);
        return b;
}

/* read one byte from the aux device, but return immediately if
 * no data is waiting
 */
int
read_aux_data_no_wait(KBDC p)
{
        unsigned char b;
        int f;

        if (availq(&p->aux))
                return removeq(&p->aux);
        f = read_status(p) & KBDS_BUFFER_FULL;
        while (f == KBDS_KBD_BUFFER_FULL) {
                DELAY(KBDD_DELAYTIME);
                b = read_data(p);
                addq(&p->kbd, b);
                f = read_status(p) & KBDS_BUFFER_FULL;
        }
        if (f == KBDS_AUX_BUFFER_FULL) {
                DELAY(KBDD_DELAYTIME);
                b = read_data(p);
                return b;
        }
        return -1; /* no data */
}

/* discard data from the keyboard */
void
empty_kbd_buffer(KBDC p, int wait)
{
        int t;
        int b;
        int f;
#if KBDIO_DEBUG >= 2
        int c1 = 0;
        int c2 = 0;
#endif
        int delta = 2;

        for (t = wait; t > 0;) {
                if ((f = read_status(p)) & KBDS_ANY_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        b = read_data(p);
                        if ((f & KBDS_BUFFER_FULL) == KBDS_AUX_BUFFER_FULL) {
                                addq(&p->aux, b);
#if KBDIO_DEBUG >= 2
                                ++c2;
                        } else {
                                ++c1;
#endif
                        }
                        t = wait;
                } else {
                        t -= delta;
                }
                DELAY(delta * 1000);
        }
#if KBDIO_DEBUG >= 2
        if ((c1 > 0) || (c2 > 0))
                log(LOG_DEBUG, "kbdc: %d:%d char read (empty_kbd_buffer)\n", c1,
                    c2);
#endif

        emptyq(&p->kbd);
}

/* discard data from the aux device */
void
empty_aux_buffer(KBDC p, int wait)
{
        int t;
        int b;
        int f;
#if KBDIO_DEBUG >= 2
        int c1 = 0;
        int c2 = 0;
#endif
        int delta = 2;

        for (t = wait; t > 0;) {
                if ((f = read_status(p)) & KBDS_ANY_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        b = read_data(p);
                        if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL) {
                                addq(&p->kbd, b);
#if KBDIO_DEBUG >= 2
                                ++c1;
                        } else {
                                ++c2;
#endif
                        }
                        t = wait;
                } else {
                        t -= delta;
                }
                DELAY(delta * 1000);
        }
#if KBDIO_DEBUG >= 2
        if ((c1 > 0) || (c2 > 0))
                log(LOG_DEBUG, "kbdc: %d:%d char read (empty_aux_buffer)\n", c1,
                    c2);
#endif

        emptyq(&p->aux);
}

/* discard any data from the keyboard or the aux device */
void
empty_both_buffers(KBDC p, int wait)
{
        int t;
        int f;
        int waited = 0;
#if KBDIO_DEBUG >= 2
        int c1 = 0;
        int c2 = 0;
#endif
        int delta = 2;

        for (t = wait; t > 0;) {
                if ((f = read_status(p)) & KBDS_ANY_BUFFER_FULL) {
                        DELAY(KBDD_DELAYTIME);
                        (void)read_data(p);
#if KBDIO_DEBUG >= 2
                        if ((f & KBDS_BUFFER_FULL) == KBDS_KBD_BUFFER_FULL)
                                ++c1;
                        else
                                ++c2;
#endif
                        t = wait;
                } else {
                        t -= delta;
                }
                /*
                * Some systems (Intel/IBM blades) do not have keyboard devices and
                * will thus hang in this procedure. Time out after delta seconds to
                * avoid this hang -- the keyboard attach will fail later on.
                */
                waited += (delta * 1000);
                if (waited == (delta * 1000000))
                        return;

                DELAY(delta * 1000);
        }
#if KBDIO_DEBUG >= 2
        if ((c1 > 0) || (c2 > 0))
                log(LOG_DEBUG, "kbdc: %d:%d char read (empty_both_buffers)\n",
                    c1, c2);
#endif

        emptyq(&p->kbd);
        emptyq(&p->aux);
}

/* keyboard and mouse device control */

/* NOTE: enable the keyboard port but disable the keyboard
 * interrupt before calling "reset_kbd()".
 */
int
reset_kbd(KBDC p)
{
        int retry = KBD_MAXRETRY;
        int again = KBD_MAXWAIT;
        int c = KBD_RESEND; /* keep the compiler happy */

        while (retry-- > 0) {
                empty_both_buffers(p, 10);
                if (!write_kbd_command(p, KBDC_RESET_KBD))
                        continue;
                emptyq(&p->kbd);
                c = read_controller_data(p);
                if (verbose || bootverbose)
                        log(LOG_DEBUG, "kbdc: RESET_KBD return code:%04x\n", c);
                if (c == KBD_ACK) /* keyboard has agreed to reset itself... */
                        break;
        }
        if (retry < 0)
                return FALSE;

        while (again-- > 0) {
                /* wait awhile, well, in fact we must wait quite loooooooooooong
                 */
                DELAY(KBD_RESETDELAY * 1000);
                c = read_controller_data(p); /* RESET_DONE/RESET_FAIL */
                if (c != -1) /* wait again if the controller is not ready */
                        break;
        }
        if (verbose || bootverbose)
                log(LOG_DEBUG, "kbdc: RESET_KBD status:%04x\n", c);
        if (c != KBD_RESET_DONE)
                return FALSE;
        return TRUE;
}

/* NOTE: enable the aux port but disable the aux interrupt
 * before calling `reset_aux_dev()'.
 */
int
reset_aux_dev(KBDC p)
{
        int retry = KBD_MAXRETRY;
        int again = KBD_MAXWAIT;
        int c = PSM_RESEND; /* keep the compiler happy */

        while (retry-- > 0) {
                empty_both_buffers(p, 10);
                if (!write_aux_command(p, PSMC_RESET_DEV))
                        continue;
                emptyq(&p->aux);
                /* NOTE: Compaq Armada laptops require extra delay here. XXX */
                for (again = KBD_MAXWAIT; again > 0; --again) {
                        DELAY(KBD_RESETDELAY * 1000);
                        c = read_aux_data_no_wait(p);
                        if (c != -1)
                                break;
                }
                if (verbose || bootverbose)
                        log(LOG_DEBUG, "kbdc: RESET_AUX return code:%04x\n", c);
                if (c == PSM_ACK) /* aux dev is about to reset... */
                        break;
        }
        if (retry < 0)
                return FALSE;

        for (again = KBD_MAXWAIT; again > 0; --again) {
                /* wait awhile, well, quite looooooooooooong */
                DELAY(KBD_RESETDELAY * 1000);
                c = read_aux_data_no_wait(p); /* RESET_DONE/RESET_FAIL */
                if (c != -1) /* wait again if the controller is not ready */
                        break;
        }
        if (verbose || bootverbose)
                log(LOG_DEBUG, "kbdc: RESET_AUX status:%04x\n", c);
        if (c != PSM_RESET_DONE) /* reset status */
                return FALSE;

        c = read_aux_data(p); /* device ID */
        if (verbose || bootverbose)
                log(LOG_DEBUG, "kbdc: RESET_AUX ID:%04x\n", c);
        /* NOTE: we could check the device ID now, but leave it later... */
        return TRUE;
}

/* controller diagnostics and setup */

int
test_controller(KBDC p)
{
        int retry = KBD_MAXRETRY;
        int again = KBD_MAXWAIT;
        int c = KBD_DIAG_FAIL;

        while (retry-- > 0) {
                empty_both_buffers(p, 10);
                if (write_controller_command(p, KBDC_DIAGNOSE))
                        break;
        }
        if (retry < 0)
                return FALSE;

        emptyq(&p->kbd);
        while (again-- > 0) {
                /* wait awhile */
                DELAY(KBD_RESETDELAY * 1000);
                c = read_controller_data(p); /* DIAG_DONE/DIAG_FAIL */
                if (c != -1) /* wait again if the controller is not ready */
                        break;
        }
        if (verbose || bootverbose)
                log(LOG_DEBUG, "kbdc: DIAGNOSE status:%04x\n", c);
        return (c == KBD_DIAG_DONE);
}

int
test_kbd_port(KBDC p)
{
        int retry = KBD_MAXRETRY;
        int again = KBD_MAXWAIT;
        int c = -1;

        while (retry-- > 0) {
                empty_both_buffers(p, 10);
                if (write_controller_command(p, KBDC_TEST_KBD_PORT))
                        break;
        }
        if (retry < 0)
                return FALSE;

        emptyq(&p->kbd);
        while (again-- > 0) {
                c = read_controller_data(p);
                if (c != -1) /* try again if the controller is not ready */
                        break;
        }
        if (verbose || bootverbose)
                log(LOG_DEBUG, "kbdc: TEST_KBD_PORT status:%04x\n", c);
        return c;
}

int
test_aux_port(KBDC p)
{
        int retry = KBD_MAXRETRY;
        int again = KBD_MAXWAIT;
        int c = -1;

        while (retry-- > 0) {
                empty_both_buffers(p, 10);
                if (write_controller_command(p, KBDC_TEST_AUX_PORT))
                        break;
        }
        if (retry < 0)
                return FALSE;

        emptyq(&p->kbd);
        while (again-- > 0) {
                c = read_controller_data(p);
                if (c != -1) /* try again if the controller is not ready */
                        break;
        }
        if (verbose || bootverbose)
                log(LOG_DEBUG, "kbdc: TEST_AUX_PORT status:%04x\n", c);
        return c;
}

int
kbdc_get_device_mask(KBDC p)
{
        return p->command_mask;
}

void
kbdc_set_device_mask(KBDC p, int mask)
{
        p->command_mask = mask &
            (((p->quirks & KBDC_QUIRK_KEEP_ACTIVATED) ? 0 :
                                                        KBD_KBD_CONTROL_BITS) |
                KBD_AUX_CONTROL_BITS);
}

int
get_controller_command_byte(KBDC p)
{
        if (p->command_byte != -1)
                return p->command_byte;
        if (!write_controller_command(p, KBDC_GET_COMMAND_BYTE))
                return -1;
        emptyq(&p->kbd);
        p->command_byte = read_controller_data(p);
        return p->command_byte;
}

int
set_controller_command_byte(KBDC p, int mask, int command)
{
        if (get_controller_command_byte(p) == -1)
                return FALSE;

        command = (p->command_byte & ~mask) | (command & mask);
        if (command & KBD_DISABLE_KBD_PORT) {
                if (!write_controller_command(p, KBDC_DISABLE_KBD_PORT))
                        return FALSE;
        }
        if (!write_controller_command(p, KBDC_SET_COMMAND_BYTE))
                return FALSE;
        if (!write_controller_data(p, command))
                return FALSE;
        p->command_byte = command;

        if (verbose)
                log(LOG_DEBUG,
                    "kbdc: new command byte:%04x (set_controller...)\n",
                    command);

        return TRUE;
}

/*
 * Rudimentary support for active PS/2 AUX port multiplexing.
 * Only write commands can be routed to a selected AUX port.
 * Source port of data processed by read commands is totally ignored.
 */
static int
set_aux_mux_state(KBDC p, int enabled)
{
        int command, version;

        if (write_controller_command(p, KBDC_FORCE_AUX_OUTPUT) == 0 ||
            write_controller_data(p, 0xF0) == 0 ||
            read_controller_data(p) != 0xF0)
                return (-1);

        if (write_controller_command(p, KBDC_FORCE_AUX_OUTPUT) == 0 ||
            write_controller_data(p, 0x56) == 0 ||
            read_controller_data(p) != 0x56)
                return (-1);

        command = enabled ? 0xa4 : 0xa5;
        if (write_controller_command(p, KBDC_FORCE_AUX_OUTPUT) == 0 ||
            write_controller_data(p, command) == 0 ||
            (version = read_controller_data(p)) == command)
                return (-1);

        return (version);
}

int
set_active_aux_mux_port(KBDC p, int port)
{

        if (!aux_mux_is_enabled(p))
                return (FALSE);

        if (port < 0 || port >= KBDC_AUX_MUX_NUM_PORTS)
                return (FALSE);

        p->aux_mux_port = port;

        return (TRUE);
}

/* Checks for active multiplexing support and enables it */
int
enable_aux_mux(KBDC p)
{
        int version;

        version = set_aux_mux_state(p, TRUE);
        if (version >= 0) {
                p->aux_mux_enabled = TRUE;
                set_active_aux_mux_port(p, 0);
        }

        return (version);
}

int
disable_aux_mux(KBDC p)
{

        p->aux_mux_enabled = FALSE;

        return (set_aux_mux_state(p, FALSE));
}

int
aux_mux_is_enabled(KBDC p)
{

        return (p->aux_mux_enabled);
}