xref: /freebsd/sys/dev/atkbdc/atkbd.c (revision d3c87b851256744a7c106899d624910aa1967d4f)

/*-
 * Copyright (c) 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 as
 *    the first lines of this file unmodified.
 * 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 AUTHORS ``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 AUTHORS 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.
 *
 * $Id: atkbd.c,v 1.9 1999/05/18 11:05:58 yokota Exp $
 */

#include "atkbd.h"
#include "opt_kbd.h"
#include "opt_atkbd.h"
#include "opt_devfs.h"

#if NATKBD > 0

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>

#include <dev/kbd/kbdreg.h>
#include <dev/kbd/atkbdreg.h>
#include <dev/kbd/atkbdcreg.h>

#include <isa/isareg.h>

#define ATKBD_SOFTC(unit)		\
	((atkbd_softc_t *)devclass_get_softc(atkbd_devclass, unit))

extern devclass_t	atkbd_devclass;

static timeout_t	atkbd_timeout;

#ifdef KBD_INSTALL_CDEV

static d_open_t		atkbdopen;
static d_close_t	atkbdclose;
static d_read_t		atkbdread;
static d_ioctl_t	atkbdioctl;
static d_poll_t		atkbdpoll;

static struct  cdevsw atkbd_cdevsw = {
	atkbdopen,	atkbdclose,	atkbdread,	nowrite,
	atkbdioctl,	nostop,		nullreset,	nodevtotty,
	atkbdpoll,	nommap,		NULL,		ATKBD_DRIVER_NAME,
	NULL,		-1,
};

#endif /* KBD_INSTALL_CDEV */

int
atkbd_probe_unit(int unit, int port, int irq, int flags)
{
	keyboard_switch_t *sw;
	int args[2];
	int error;

	sw = kbd_get_switch(ATKBD_DRIVER_NAME);
	if (sw == NULL)
		return ENXIO;

	args[0] = port;
	args[1] = irq;
	error = (*sw->probe)(unit, args, flags);
	if (error)
		return error;
	return 0;
}

int
atkbd_attach_unit(int unit, atkbd_softc_t *sc, int port, int irq, int flags)
{
	keyboard_switch_t *sw;
	int args[2];
	int error;

	if (sc->flags & ATKBD_ATTACHED)
		return 0;

	sw = kbd_get_switch(ATKBD_DRIVER_NAME);
	if (sw == NULL)
		return ENXIO;

	/* reset, initialize and enable the device */
	args[0] = port;
	args[1] = irq;
	sc->kbd = NULL;
	error = (*sw->probe)(unit, args, flags);
	if (error)
		return error;
	error = (*sw->init)(unit, &sc->kbd, args, flags);
	if (error)
		return error;
	(*sw->enable)(sc->kbd);

#ifdef KBD_INSTALL_CDEV
	/* attach a virtual keyboard cdev */
	error = kbd_attach(makedev(0, ATKBD_MKMINOR(unit)), sc->kbd,
			   &atkbd_cdevsw);
	if (error)
		return error;
#endif

	/*
	 * This is a kludge to compensate for lost keyboard interrupts.
	 * A similar code used to be in syscons. See below. XXX
	 */
	atkbd_timeout(sc->kbd);

	if (bootverbose)
		(*sw->diag)(sc->kbd, bootverbose);

	sc->flags |= ATKBD_ATTACHED;
	return 0;
}

static void
atkbd_timeout(void *arg)
{
	keyboard_t *kbd;
	int s;

	/* The following comments are extracted from syscons.c (1.287) */
	/*
	 * With release 2.1 of the Xaccel server, the keyboard is left
	 * hanging pretty often. Apparently an interrupt from the
	 * keyboard is lost, and I don't know why (yet).
	 * This ugly hack calls scintr if input is ready for the keyboard
	 * and conveniently hides the problem.			XXX
	 */
	/*
	 * Try removing anything stuck in the keyboard controller; whether
	 * it's a keyboard scan code or mouse data. `scintr()' doesn't
	 * read the mouse data directly, but `kbdio' routines will, as a
	 * side effect.
	 */
	s = spltty();
	kbd = (keyboard_t *)arg;
	if ((*kbdsw[kbd->kb_index]->lock)(kbd, TRUE)) {
		/*
		 * We have seen the lock flag is not set. Let's reset
		 * the flag early, otherwise the LED update routine fails
		 * which may want the lock during the interrupt routine.
		 */
		(*kbdsw[kbd->kb_index]->lock)(kbd, FALSE);
		if ((*kbdsw[kbd->kb_index]->check_char)(kbd))
			(*kbdsw[kbd->kb_index]->intr)(kbd, NULL);
	}
	splx(s);
	timeout(atkbd_timeout, arg, hz/10);
}

/* cdev driver functions */

#ifdef KBD_INSTALL_CDEV

static int
atkbdopen(dev_t dev, int flag, int mode, struct proc *p)
{
	atkbd_softc_t *sc;

	sc = ATKBD_SOFTC(ATKBD_UNIT(dev));
	if (sc == NULL)
		return ENXIO;
	if (mode & (FWRITE | O_CREAT | O_APPEND | O_TRUNC))
		return ENODEV;

	/* FIXME: set the initial input mode (K_XLATE?) and lock state? */
	return genkbdopen(&sc->gensc, sc->kbd, flag, mode, p);
}

static int
atkbdclose(dev_t dev, int flag, int mode, struct proc *p)
{
	atkbd_softc_t *sc;

	sc = ATKBD_SOFTC(ATKBD_UNIT(dev));
	return genkbdclose(&sc->gensc, sc->kbd, flag, mode, p);
}

static int
atkbdread(dev_t dev, struct uio *uio, int flag)
{
	atkbd_softc_t *sc;

	sc = ATKBD_SOFTC(ATKBD_UNIT(dev));
	return genkbdread(&sc->gensc, sc->kbd, uio, flag);
}

static int
atkbdioctl(dev_t dev, u_long cmd, caddr_t arg, int flag, struct proc *p)
{
	atkbd_softc_t *sc;

	sc = ATKBD_SOFTC(ATKBD_UNIT(dev));
	return genkbdioctl(&sc->gensc, sc->kbd, cmd, arg, flag, p);
}

static int
atkbdpoll(dev_t dev, int event, struct proc *p)
{
	atkbd_softc_t *sc;

	sc = ATKBD_SOFTC(ATKBD_UNIT(dev));
	return genkbdpoll(&sc->gensc, sc->kbd, event, p);
}

#endif /* KBD_INSTALL_CDEV */

/* LOW-LEVEL */

#include <machine/limits.h>
#include <machine/console.h>
#include <machine/clock.h>

#define ATKBD_DEFAULT	0

typedef struct atkbd_state {
	KBDC		kbdc;		/* keyboard controller */
					/* XXX: don't move this field; pcvt
					 * expects `kbdc' to be the first
					 * field in this structure. */
	int		ks_mode;	/* input mode (K_XLATE,K_RAW,K_CODE) */
	int		ks_flags;	/* flags */
#define COMPOSE		(1 << 0)
	int		ks_polling;
	int		ks_state;	/* shift/lock key state */
	int		ks_accents;	/* accent key index (> 0) */
	u_int		ks_composed_char; /* composed char code (> 0) */
	u_char		ks_prefix;	/* AT scan code prefix */
} atkbd_state_t;

/* keyboard driver declaration */
static int		atkbd_configure(int flags);
static kbd_probe_t	atkbd_probe;
static kbd_init_t	atkbd_init;
static kbd_term_t	atkbd_term;
static kbd_intr_t	atkbd_intr;
static kbd_test_if_t	atkbd_test_if;
static kbd_enable_t	atkbd_enable;
static kbd_disable_t	atkbd_disable;
static kbd_read_t	atkbd_read;
static kbd_check_t	atkbd_check;
static kbd_read_char_t	atkbd_read_char;
static kbd_check_char_t	atkbd_check_char;
static kbd_ioctl_t	atkbd_ioctl;
static kbd_lock_t	atkbd_lock;
static kbd_clear_state_t atkbd_clear_state;
static kbd_get_state_t	atkbd_get_state;
static kbd_set_state_t	atkbd_set_state;
static kbd_poll_mode_t	atkbd_poll;

keyboard_switch_t atkbdsw = {
	atkbd_probe,
	atkbd_init,
	atkbd_term,
	atkbd_intr,
	atkbd_test_if,
	atkbd_enable,
	atkbd_disable,
	atkbd_read,
	atkbd_check,
	atkbd_read_char,
	atkbd_check_char,
	atkbd_ioctl,
	atkbd_lock,
	atkbd_clear_state,
	atkbd_get_state,
	atkbd_set_state,
	genkbd_get_fkeystr,
	atkbd_poll,
	genkbd_diag,
};

KEYBOARD_DRIVER(atkbd, atkbdsw, atkbd_configure);

/* local functions */
static int		setup_kbd_port(KBDC kbdc, int port, int intr);
static int		get_kbd_echo(KBDC kbdc);
static int		probe_keyboard(KBDC kbdc, int flags);
static int		init_keyboard(KBDC kbdc, int *type, int flags);
static int		write_kbd(KBDC kbdc, int command, int data);
static int		get_kbd_id(KBDC kbdc);
static int		typematic(int delay, int rate);

/* local variables */

/* the initial key map, accent map and fkey strings */
#ifdef ATKBD_DFLT_KEYMAP
#define KBD_DFLT_KEYMAP
#include "atkbdmap.h"
#endif
#include <dev/kbd/kbdtables.h>

/* structures for the default keyboard */
static keyboard_t	default_kbd;
static atkbd_state_t	default_kbd_state;
static keymap_t		default_keymap;
static accentmap_t	default_accentmap;
static fkeytab_t	default_fkeytab[NUM_FKEYS];

/*
 * The back door to the keyboard driver!
 * This function is called by the console driver, via the kbdio module,
 * to tickle keyboard drivers when the low-level console is being initialized.
 * Almost nothing in the kernel has been initialied yet.  Try to probe
 * keyboards if possible.
 * NOTE: because of the way the low-level conole is initialized, this routine
 * may be called more than once!!
 */
static int
atkbd_configure(int flags)
{
	keyboard_t *kbd;
	int arg[2];
	int i;

	/* if the driver is disabled, unregister the keyboard if any */
	if ((resource_int_value("atkbd", ATKBD_DEFAULT, "disabled", &i) == 0)
	    && i != 0) {
		i = kbd_find_keyboard(ATKBD_DRIVER_NAME, ATKBD_DEFAULT);
		if (i >= 0) {
			kbd = kbd_get_keyboard(i);
			kbd_unregister(kbd);
			kbd->kb_flags &= ~KB_REGISTERED;
			return 0;
		}
	}

	/* XXX: a kludge to obtain the device configuration flags */
	if (resource_int_value("atkbd", ATKBD_DEFAULT, "flags", &i) == 0)
		flags |= i;

	/* probe the keyboard controller */
	atkbdc_configure();

	/* probe the default keyboard */
	arg[0] = -1;
	arg[1] = -1;
	kbd = NULL;
	if (atkbd_probe(ATKBD_DEFAULT, arg, flags))
		return 0;
	if (atkbd_init(ATKBD_DEFAULT, &kbd, arg, flags))
		return 0;

	/* return the number of found keyboards */
	return 1;
}

/* low-level functions */

/* detect a keyboard */
static int
atkbd_probe(int unit, void *arg, int flags)
{
	KBDC kbdc;
	int *data = (int *)arg;

	/* XXX */
	if (unit == ATKBD_DEFAULT) {
		if (KBD_IS_PROBED(&default_kbd))
			return 0;
	}

	kbdc = kbdc_open(data[0]);
	if (kbdc == NULL)
		return ENXIO;
	if (probe_keyboard(kbdc, flags)) {
		if (flags & KB_CONF_FAIL_IF_NO_KBD)
			return ENXIO;
	}
	return 0;
}

/* reset and initialize the device */
static int
atkbd_init(int unit, keyboard_t **kbdp, void *arg, int flags)
{
	keyboard_t *kbd;
	atkbd_state_t *state;
	keymap_t *keymap;
	accentmap_t *accmap;
	fkeytab_t *fkeymap;
	int fkeymap_size;
	int *data = (int *)arg;

	/* XXX */
	if (unit == ATKBD_DEFAULT) {
		*kbdp = kbd = &default_kbd;
		if (KBD_IS_INITIALIZED(kbd) && KBD_IS_CONFIGURED(kbd))
			return 0;
		state = &default_kbd_state;
		keymap = &default_keymap;
		accmap = &default_accentmap;
		fkeymap = default_fkeytab;
		fkeymap_size =
			sizeof(default_fkeytab)/sizeof(default_fkeytab[0]);
	} else if (*kbdp == NULL) {
		*kbdp = kbd = malloc(sizeof(*kbd), M_DEVBUF, M_NOWAIT);
		if (kbd == NULL)
			return ENOMEM;
		bzero(kbd, sizeof(*kbd));
		state = malloc(sizeof(*state), M_DEVBUF, M_NOWAIT);
		keymap = malloc(sizeof(key_map), M_DEVBUF, M_NOWAIT);
		accmap = malloc(sizeof(accent_map), M_DEVBUF, M_NOWAIT);
		fkeymap = malloc(sizeof(fkey_tab), M_DEVBUF, M_NOWAIT);
		fkeymap_size = sizeof(fkey_tab)/sizeof(fkey_tab[0]);
		if ((state == NULL) || (keymap == NULL) || (accmap == NULL)
		     || (fkeymap == NULL)) {
			if (state != NULL)
				free(state, M_DEVBUF);
			if (keymap != NULL)
				free(keymap, M_DEVBUF);
			if (accmap != NULL)
				free(accmap, M_DEVBUF);
			if (fkeymap != NULL)
				free(fkeymap, M_DEVBUF);
			free(kbd, M_DEVBUF);
			return ENOMEM;
		}
		bzero(state, sizeof(*state));
	} else if (KBD_IS_INITIALIZED(*kbdp) && KBD_IS_CONFIGURED(*kbdp)) {
		return 0;
	} else {
		kbd = *kbdp;
		state = (atkbd_state_t *)kbd->kb_data;
		bzero(state, sizeof(*state));
		keymap = kbd->kb_keymap;
		accmap = kbd->kb_accentmap;
		fkeymap = kbd->kb_fkeytab;
		fkeymap_size = kbd->kb_fkeytab_size;
	}

	if (!KBD_IS_PROBED(kbd)) {
		state->kbdc = kbdc_open(data[0]);
		if (state->kbdc == NULL)
			return ENXIO;
		kbd_init_struct(kbd, ATKBD_DRIVER_NAME, KB_OTHER, unit, flags,
				data[0], IO_KBDSIZE);
		bcopy(&key_map, keymap, sizeof(key_map));
		bcopy(&accent_map, accmap, sizeof(accent_map));
		bcopy(fkey_tab, fkeymap,
		      imin(fkeymap_size*sizeof(fkeymap[0]), sizeof(fkey_tab)));
		kbd_set_maps(kbd, keymap, accmap, fkeymap, fkeymap_size);
		kbd->kb_data = (void *)state;

		if (probe_keyboard(state->kbdc, flags)) { /* shouldn't happen */
			if (flags & KB_CONF_FAIL_IF_NO_KBD)
				return ENXIO;
		} else {
			KBD_FOUND_DEVICE(kbd);
		}
		atkbd_clear_state(kbd);
		state->ks_mode = K_XLATE;
		/*
		 * FIXME: set the initial value for lock keys in ks_state
		 * according to the BIOS data?
		 */
		KBD_PROBE_DONE(kbd);
	}
	if (!KBD_IS_INITIALIZED(kbd) && !(flags & KB_CONF_PROBE_ONLY)) {
		if (KBD_HAS_DEVICE(kbd)
	    	    && init_keyboard(state->kbdc, &kbd->kb_type, kbd->kb_config)
	    	    && (kbd->kb_config & KB_CONF_FAIL_IF_NO_KBD))
			return ENXIO;
		atkbd_ioctl(kbd, KDSETLED, (caddr_t)&state->ks_state);
		KBD_INIT_DONE(kbd);
	}
	if (!KBD_IS_CONFIGURED(kbd)) {
		if (kbd_register(kbd) < 0)
			return ENXIO;
		KBD_CONFIG_DONE(kbd);
	}

	return 0;
}

/* finish using this keyboard */
static int
atkbd_term(keyboard_t *kbd)
{
	kbd_unregister(kbd);
	return 0;
}

/* keyboard interrupt routine */
static int
atkbd_intr(keyboard_t *kbd, void *arg)
{
	atkbd_state_t *state;
	int c;

	if (KBD_IS_ACTIVE(kbd) && KBD_IS_BUSY(kbd)) {
		/* let the callback function to process the input */
		(*kbd->kb_callback.kc_func)(kbd, KBDIO_KEYINPUT,
					    kbd->kb_callback.kc_arg);
	} else {
		/* read and discard the input; no one is waiting for input */
		do {
			c = atkbd_read_char(kbd, FALSE);
		} while (c != NOKEY);

		if (!KBD_HAS_DEVICE(kbd)) {
			/*
			 * The keyboard was not detected before;
			 * it must have been reconnected!
			 */
			state = (atkbd_state_t *)kbd->kb_data;
			init_keyboard(state->kbdc, &kbd->kb_type,
				      kbd->kb_config);
			atkbd_ioctl(kbd, KDSETLED, (caddr_t)&state->ks_state);
			KBD_FOUND_DEVICE(kbd);
		}
	}
	return 0;
}

/* test the interface to the device */
static int
atkbd_test_if(keyboard_t *kbd)
{
	int error;
	int s;

	error = 0;
	empty_both_buffers(((atkbd_state_t *)kbd->kb_data)->kbdc, 10);
	s = spltty();
	if (!test_controller(((atkbd_state_t *)kbd->kb_data)->kbdc))
		error = EIO;
	else if (test_kbd_port(((atkbd_state_t *)kbd->kb_data)->kbdc) != 0)
		error = EIO;
	splx(s);

	return error;
}

/*
 * Enable the access to the device; until this function is called,
 * the client cannot read from the keyboard.
 */
static int
atkbd_enable(keyboard_t *kbd)
{
	int s;

	s = spltty();
	KBD_ACTIVATE(kbd);
	splx(s);
	return 0;
}

/* disallow the access to the device */
static int
atkbd_disable(keyboard_t *kbd)
{
	int s;

	s = spltty();
	KBD_DEACTIVATE(kbd);
	splx(s);
	return 0;
}

/* read one byte from the keyboard if it's allowed */
static int
atkbd_read(keyboard_t *kbd, int wait)
{
	int c;

	if (wait)
		c = read_kbd_data(((atkbd_state_t *)kbd->kb_data)->kbdc);
	else
		c = read_kbd_data_no_wait(((atkbd_state_t *)kbd->kb_data)->kbdc);
	return (KBD_IS_ACTIVE(kbd) ? c : -1);
}

/* check if data is waiting */
static int
atkbd_check(keyboard_t *kbd)
{
	if (!KBD_IS_ACTIVE(kbd))
		return FALSE;
	return kbdc_data_ready(((atkbd_state_t *)kbd->kb_data)->kbdc);
}

/* read char from the keyboard */
static u_int
atkbd_read_char(keyboard_t *kbd, int wait)
{
	atkbd_state_t *state;
	u_int action;
	int scancode;
	int keycode;

	state = (atkbd_state_t *)kbd->kb_data;
next_code:
	/* do we have a composed char to return? */
	if (!(state->ks_flags & COMPOSE) && (state->ks_composed_char > 0)) {
		action = state->ks_composed_char;
		state->ks_composed_char = 0;
		if (action > UCHAR_MAX)
			return ERRKEY;
		return action;
	}

	/* see if there is something in the keyboard port */
	if (wait) {
		do {
			scancode = read_kbd_data(state->kbdc);
		} while (scancode == -1);
	} else {
		scancode = read_kbd_data_no_wait(state->kbdc);
		if (scancode == -1)
			return NOKEY;
	}

	/* return the byte as is for the K_RAW mode */
	if (state->ks_mode == K_RAW)
		return scancode;

	/* translate the scan code into a keycode */
	keycode = scancode & 0x7F;
	switch (state->ks_prefix) {
	case 0x00:	/* normal scancode */
		switch(scancode) {
		case 0xB8:	/* left alt (compose key) released */
			if (state->ks_flags & COMPOSE) {
				state->ks_flags &= ~COMPOSE;
				if (state->ks_composed_char > UCHAR_MAX)
					state->ks_composed_char = 0;
			}
			break;
		case 0x38:	/* left alt (compose key) pressed */
			if (!(state->ks_flags & COMPOSE)) {
				state->ks_flags |= COMPOSE;
				state->ks_composed_char = 0;
			}
			break;
		case 0xE0:
		case 0xE1:
			state->ks_prefix = scancode;
			goto next_code;
		}
		break;
	case 0xE0:      /* 0xE0 prefix */
		state->ks_prefix = 0;
		switch (keycode) {
		case 0x1C:	/* right enter key */
			keycode = 0x59;
			break;
		case 0x1D:	/* right ctrl key */
			keycode = 0x5A;
			break;
		case 0x35:	/* keypad divide key */
	    		keycode = 0x5B;
	    		break;
		case 0x37:	/* print scrn key */
	    		keycode = 0x5C;
	    		break;
		case 0x38:	/* right alt key (alt gr) */
	    		keycode = 0x5D;
	    		break;
		case 0x46:	/* ctrl-pause/break on AT 101 (see below) */
			keycode = 0x68;
	    		break;
		case 0x47:	/* grey home key */
	    		keycode = 0x5E;
	    		break;
		case 0x48:	/* grey up arrow key */
	    		keycode = 0x5F;
	    		break;
		case 0x49:	/* grey page up key */
	    		keycode = 0x60;
	    		break;
		case 0x4B:	/* grey left arrow key */
	    		keycode = 0x61;
	    		break;
		case 0x4D:	/* grey right arrow key */
	    		keycode = 0x62;
	    		break;
		case 0x4F:	/* grey end key */
	    		keycode = 0x63;
	    		break;
		case 0x50:	/* grey down arrow key */
	    		keycode = 0x64;
	    		break;
		case 0x51:	/* grey page down key */
	    		keycode = 0x65;
	    		break;
		case 0x52:	/* grey insert key */
	    		keycode = 0x66;
	    		break;
		case 0x53:	/* grey delete key */
	    		keycode = 0x67;
	    		break;
		/* the following 3 are only used on the MS "Natural" keyboard */
		case 0x5b:	/* left Window key */
	    		keycode = 0x69;
	    		break;
		case 0x5c:	/* right Window key */
	    		keycode = 0x6a;
	    		break;
		case 0x5d:	/* menu key */
	    		keycode = 0x6b;
	    		break;
		default:	/* ignore everything else */
	    		goto next_code;
		}
		break;
    	case 0xE1:	/* 0xE1 prefix */
		/*
		 * The pause/break key on the 101 keyboard produces:
		 * E1-1D-45 E1-9D-C5
		 * Ctrl-pause/break produces:
		 * E0-46 E0-C6 (See above.)
		 */
		state->ks_prefix = 0;
		if (keycode == 0x1D)
	    		state->ks_prefix = 0x1D;
		goto next_code;
		/* NOT REACHED */
    	case 0x1D:	/* pause / break */
		state->ks_prefix = 0;
		if (keycode != 0x45)
			goto next_code;
		keycode = 0x68;
		break;
	}

	if (kbd->kb_type == KB_84) {
		switch (keycode) {
		case 0x37:	/* *(numpad)/print screen */
			if (state->ks_flags & SHIFTS)
	    			keycode = 0x5c;	/* print screen */
			break;
		case 0x45:	/* num lock/pause */
			if (state->ks_flags & CTLS)
				keycode = 0x68;	/* pause */
			break;
		case 0x46:	/* scroll lock/break */
			if (state->ks_flags & CTLS)
				keycode = 0x6c;	/* break */
			break;
		}
	} else if (kbd->kb_type == KB_101) {
		switch (keycode) {
		case 0x5c:	/* print screen */
			if (state->ks_flags & ALTS)
				keycode = 0x54;	/* sysrq */
			break;
		case 0x68:	/* pause/break */
			if (state->ks_flags & CTLS)
				keycode = 0x6c;	/* break */
			break;
		}
	}

	/* return the key code in the K_CODE mode */
	if (state->ks_mode == K_CODE)
		return (keycode | (scancode & 0x80));

	/* compose a character code */
	if (state->ks_flags & COMPOSE) {
		switch (keycode | (scancode & 0x80)) {
		/* key pressed, process it */
		case 0x47: case 0x48: case 0x49:	/* keypad 7,8,9 */
			state->ks_composed_char *= 10;
			state->ks_composed_char += keycode - 0x40;
			if (state->ks_composed_char > UCHAR_MAX)
				return ERRKEY;
			goto next_code;
		case 0x4B: case 0x4C: case 0x4D:	/* keypad 4,5,6 */
			state->ks_composed_char *= 10;
			state->ks_composed_char += keycode - 0x47;
			if (state->ks_composed_char > UCHAR_MAX)
				return ERRKEY;
			goto next_code;
		case 0x4F: case 0x50: case 0x51:	/* keypad 1,2,3 */
			state->ks_composed_char *= 10;
			state->ks_composed_char += keycode - 0x4E;
			if (state->ks_composed_char > UCHAR_MAX)
				return ERRKEY;
			goto next_code;
		case 0x52:				/* keypad 0 */
			state->ks_composed_char *= 10;
			if (state->ks_composed_char > UCHAR_MAX)
				return ERRKEY;
			goto next_code;

		/* key released, no interest here */
		case 0xC7: case 0xC8: case 0xC9:	/* keypad 7,8,9 */
		case 0xCB: case 0xCC: case 0xCD:	/* keypad 4,5,6 */
		case 0xCF: case 0xD0: case 0xD1:	/* keypad 1,2,3 */
		case 0xD2:				/* keypad 0 */
			goto next_code;

		case 0x38:				/* left alt key */
			break;

		default:
			if (state->ks_composed_char > 0) {
				state->ks_flags &= ~COMPOSE;
				state->ks_composed_char = 0;
				return ERRKEY;
			}
			break;
		}
	}

	/* keycode to key action */
	action = genkbd_keyaction(kbd, keycode, scancode & 0x80,
				  &state->ks_state, &state->ks_accents);
	if (action == NOKEY)
		goto next_code;
	else
		return action;
}

/* check if char is waiting */
static int
atkbd_check_char(keyboard_t *kbd)
{
	atkbd_state_t *state;

	if (!KBD_IS_ACTIVE(kbd))
		return FALSE;
	state = (atkbd_state_t *)kbd->kb_data;
	if (!(state->ks_flags & COMPOSE) && (state->ks_composed_char > 0))
		return TRUE;
	return kbdc_data_ready(state->kbdc);
}

/* some useful control functions */
static int
atkbd_ioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)
{
	/* trasnlate LED_XXX bits into the device specific bits */
	static u_char ledmap[8] = {
		0, 4, 2, 6, 1, 5, 3, 7,
	};
	atkbd_state_t *state = kbd->kb_data;
	int error;
	int s;
	int i;

	s = spltty();
	switch (cmd) {

	case KDGKBMODE:		/* get keyboard mode */
		*(int *)arg = state->ks_mode;
		break;
	case KDSKBMODE:		/* set keyboard mode */
		switch (*(int *)arg) {
		case K_XLATE:
			if (state->ks_mode != K_XLATE) {
				/* make lock key state and LED state match */
				state->ks_state &= ~LOCK_MASK;
				state->ks_state |= KBD_LED_VAL(kbd);
			}
			/* FALL THROUGH */
		case K_RAW:
		case K_CODE:
			if (state->ks_mode != *(int *)arg) {
				atkbd_clear_state(kbd);
				state->ks_mode = *(int *)arg;
			}
			break;
		default:
			splx(s);
			return EINVAL;
		}
		break;

	case KDGETLED:		/* get keyboard LED */
		*(int *)arg = KBD_LED_VAL(kbd);
		break;
	case KDSETLED:		/* set keyboard LED */
		/* NOTE: lock key state in ks_state won't be changed */
		if (*(int *)arg & ~LOCK_MASK) {
			splx(s);
			return EINVAL;
		}
		i = *(int *)arg;
		/* replace CAPS LED with ALTGR LED for ALTGR keyboards */
		if (kbd->kb_keymap->n_keys > ALTGR_OFFSET) {
			if (i & ALKED)
				i |= CLKED;
			else
				i &= ~CLKED;
		}
		if (KBD_HAS_DEVICE(kbd)) {
			error = write_kbd(state->kbdc, KBDC_SET_LEDS,
					  ledmap[i & LED_MASK]);
			if (error) {
				splx(s);
				return error;
			}
		}
		KBD_LED_VAL(kbd) = *(int *)arg;
		break;

	case KDGKBSTATE:	/* get lock key state */
		*(int *)arg = state->ks_state & LOCK_MASK;
		break;
	case KDSKBSTATE:	/* set lock key state */
		if (*(int *)arg & ~LOCK_MASK) {
			splx(s);
			return EINVAL;
		}
		state->ks_state &= ~LOCK_MASK;
		state->ks_state |= *(int *)arg;
		splx(s);
		/* set LEDs and quit */
		return atkbd_ioctl(kbd, KDSETLED, arg);

	case KDSETREPEAT:	/* set keyboard repeat rate (new interface) */
		splx(s);
		if (!KBD_HAS_DEVICE(kbd))
			return 0;
		i = typematic(((int *)arg)[0], ((int *)arg)[1]);
		return write_kbd(state->kbdc, KBDC_SET_TYPEMATIC, i);

	case KDSETRAD:		/* set keyboard repeat rate (old interface) */
		splx(s);
		if (!KBD_HAS_DEVICE(kbd))
			return 0;
		return write_kbd(state->kbdc, KBDC_SET_TYPEMATIC, *(int *)arg);

	case PIO_KEYMAP:	/* set keyboard translation table */
	case PIO_KEYMAPENT:	/* set keyboard translation table entry */
	case PIO_DEADKEYMAP:	/* set accent key translation table */
		state->ks_accents = 0;
		/* FALL THROUGH */
	default:
		splx(s);
		return genkbd_commonioctl(kbd, cmd, arg);
	}

	splx(s);
	return 0;
}

/* lock the access to the keyboard */
static int
atkbd_lock(keyboard_t *kbd, int lock)
{
	return kbdc_lock(((atkbd_state_t *)kbd->kb_data)->kbdc, lock);
}

/* clear the internal state of the keyboard */
static void
atkbd_clear_state(keyboard_t *kbd)
{
	atkbd_state_t *state;

	state = (atkbd_state_t *)kbd->kb_data;
	state->ks_flags = 0;
	state->ks_polling = 0;
	state->ks_state &= LOCK_MASK;	/* preserve locking key state */
	state->ks_accents = 0;
	state->ks_composed_char = 0;
#if 0
	state->ks_prefix = 0; /* XXX */
#endif
}

/* save the internal state */
static int
atkbd_get_state(keyboard_t *kbd, void *buf, size_t len)
{
	if (len == 0)
		return sizeof(atkbd_state_t);
	if (len < sizeof(atkbd_state_t))
		return -1;
	bcopy(kbd->kb_data, buf, sizeof(atkbd_state_t));
	return 0;
}

/* set the internal state */
static int
atkbd_set_state(keyboard_t *kbd, void *buf, size_t len)
{
	if (len < sizeof(atkbd_state_t))
		return ENOMEM;
	if (((atkbd_state_t *)kbd->kb_data)->kbdc
		!= ((atkbd_state_t *)buf)->kbdc)
		return ENOMEM;
	bcopy(buf, kbd->kb_data, sizeof(atkbd_state_t));
	return 0;
}

static int
atkbd_poll(keyboard_t *kbd, int on)
{
	atkbd_state_t *state;
	int s;

	state = (atkbd_state_t *)kbd->kb_data;
	s = spltty();
	if (on)
		++state->ks_polling;
	else
		--state->ks_polling;
	splx(s);
	return 0;
}

/* local functions */

static int
setup_kbd_port(KBDC kbdc, int port, int intr)
{
	if (!set_controller_command_byte(kbdc,
		KBD_KBD_CONTROL_BITS,
		((port) ? KBD_ENABLE_KBD_PORT : KBD_DISABLE_KBD_PORT)
		    | ((intr) ? KBD_ENABLE_KBD_INT : KBD_DISABLE_KBD_INT)))
		return 1;
	return 0;
}

static int
get_kbd_echo(KBDC kbdc)
{
	/* enable the keyboard port, but disable the keyboard intr. */
	if (setup_kbd_port(kbdc, TRUE, FALSE))
		/* CONTROLLER ERROR: there is very little we can do... */
		return ENXIO;

	/* see if something is present */
	write_kbd_command(kbdc, KBDC_ECHO);
	if (read_kbd_data(kbdc) != KBD_ECHO) {
		empty_both_buffers(kbdc, 10);
		test_controller(kbdc);
		test_kbd_port(kbdc);
		return ENXIO;
	}

	/* enable the keyboard port and intr. */
	if (setup_kbd_port(kbdc, TRUE, TRUE)) {
		/*
		 * CONTROLLER ERROR
		 * This is serious; the keyboard intr is left disabled!
		 */
		return ENXIO;
	}

	return 0;
}

static int
probe_keyboard(KBDC kbdc, int flags)
{
	/*
	 * Don't try to print anything in this function.  The low-level
	 * console may not have been initialized yet...
	 */
	int err;
	int c;
	int m;

	if (!kbdc_lock(kbdc, TRUE)) {
		/* driver error? */
		return ENXIO;
	}

	/* flush any noise in the buffer */
	empty_both_buffers(kbdc, 10);

	/* save the current keyboard controller command byte */
	m = kbdc_get_device_mask(kbdc) & ~KBD_KBD_CONTROL_BITS;
	c = get_controller_command_byte(kbdc);
	if (c == -1) {
		/* CONTROLLER ERROR */
		kbdc_set_device_mask(kbdc, m);
		kbdc_lock(kbdc, FALSE);
		return ENXIO;
	}

	/*
	 * The keyboard may have been screwed up by the boot block.
	 * We may just be able to recover from error by testing the controller
	 * and the keyboard port. The controller command byte needs to be
	 * saved before this recovery operation, as some controllers seem
	 * to set the command byte to particular values.
	 */
	test_controller(kbdc);
	test_kbd_port(kbdc);

	err = get_kbd_echo(kbdc);
	if (err == 0) {
		kbdc_set_device_mask(kbdc, m | KBD_KBD_CONTROL_BITS);
	} else {
		if (c != -1)
			/* try to restore the command byte as before */
			set_controller_command_byte(kbdc, 0xff, c);
		kbdc_set_device_mask(kbdc, m);
	}

	kbdc_lock(kbdc, FALSE);
	return err;
}

static int
init_keyboard(KBDC kbdc, int *type, int flags)
{
	int codeset;
	int id;
	int c;

	if (!kbdc_lock(kbdc, TRUE)) {
		/* driver error? */
		return EIO;
	}

	/* save the current controller command byte */
	empty_both_buffers(kbdc, 10);
	c = get_controller_command_byte(kbdc);
	if (c == -1) {
		/* CONTROLLER ERROR */
		kbdc_lock(kbdc, FALSE);
		printf("atkbd: unable to get the current command byte value.\n");
		return EIO;
	}
	if (bootverbose)
		printf("atkbd: the current kbd controller command byte %04x\n",
		       c);
#if 0
	/* override the keyboard lock switch */
	c |= KBD_OVERRIDE_KBD_LOCK;
#endif

	/* enable the keyboard port, but disable the keyboard intr. */
	if (setup_kbd_port(kbdc, TRUE, FALSE)) {
		/* CONTROLLER ERROR: there is very little we can do... */
		printf("atkbd: unable to set the command byte.\n");
		kbdc_lock(kbdc, FALSE);
		return EIO;
	}

	/*
	 * Check if we have an XT keyboard before we attempt to reset it.
	 * The procedure assumes that the keyboard and the controller have
	 * been set up properly by BIOS and have not been messed up
	 * during the boot process.
	 */
	codeset = -1;
	if (flags & KB_CONF_ALT_SCANCODESET)
		/* the user says there is a XT keyboard */
		codeset = 1;
#ifdef KBD_DETECT_XT_KEYBOARD
	else if ((c & KBD_TRANSLATION) == 0) {
		/* SET_SCANCODE_SET is not always supported; ignore error */
		if (send_kbd_command_and_data(kbdc, KBDC_SET_SCANCODE_SET, 0)
			== KBD_ACK)
			codeset = read_kbd_data(kbdc);
	}
	if (bootverbose)
		printf("atkbd: scancode set %d\n", codeset);
#endif /* KBD_DETECT_XT_KEYBOARD */

	*type = KB_OTHER;
	id = get_kbd_id(kbdc);
	switch(id) {
	case 0x41ab:
	case 0x83ab:
		*type = KB_101;
		break;
	case -1:	/* AT 84 keyboard doesn't return ID */
		*type = KB_84;
		break;
	default:
		break;
	}
	if (bootverbose)
		printf("atkbd: keyboard ID 0x%x (%d)\n", id, *type);

	/* reset keyboard hardware */
	if (!(flags & KB_CONF_NO_RESET) && !reset_kbd(kbdc)) {
		/*
		 * KEYBOARD ERROR
		 * Keyboard reset may fail either because the keyboard
		 * doen't exist, or because the keyboard doesn't pass
		 * the self-test, or the keyboard controller on the
		 * motherboard and the keyboard somehow fail to shake hands.
		 * It is just possible, particularly in the last case,
		 * that the keyoard controller may be left in a hung state.
		 * test_controller() and test_kbd_port() appear to bring
		 * the keyboard controller back (I don't know why and how,
		 * though.)
		 */
		empty_both_buffers(kbdc, 10);
		test_controller(kbdc);
		test_kbd_port(kbdc);
		/*
		 * We could disable the keyboard port and interrupt... but,
		 * the keyboard may still exist (see above).
		 */
		set_controller_command_byte(kbdc, 0xff, c);
		kbdc_lock(kbdc, FALSE);
		if (bootverbose)
			printf("atkbd: failed to reset the keyboard.\n");
		return EIO;
	}

	/*
	 * Allow us to set the XT_KEYBD flag in UserConfig so that keyboards
	 * such as those on the IBM ThinkPad laptop computers can be used
	 * with the standard console driver.
	 */
	if (codeset == 1) {
		if (send_kbd_command_and_data(kbdc,
			KBDC_SET_SCANCODE_SET, codeset) == KBD_ACK) {
			/* XT kbd doesn't need scan code translation */
			c &= ~KBD_TRANSLATION;
		} else {
			/*
			 * KEYBOARD ERROR
			 * The XT kbd isn't usable unless the proper scan
			 * code set is selected.
			 */
			set_controller_command_byte(kbdc, 0xff, c);
			kbdc_lock(kbdc, FALSE);
			printf("atkbd: unable to set the XT keyboard mode.\n");
			return EIO;
		}
	}

#ifdef __alpha__
	if (send_kbd_command_and_data(
		kbdc, KBDC_SET_SCANCODE_SET, 2) != KBD_ACK) {
		printf("atkbd: can't set translation.\n");

	}
	c |= KBD_TRANSLATION;
#endif

	/* enable the keyboard port and intr. */
	if (!set_controller_command_byte(kbdc,
		KBD_KBD_CONTROL_BITS | KBD_TRANSLATION | KBD_OVERRIDE_KBD_LOCK,
		(c & (KBD_TRANSLATION | KBD_OVERRIDE_KBD_LOCK))
		    | KBD_ENABLE_KBD_PORT | KBD_ENABLE_KBD_INT)) {
		/*
		 * CONTROLLER ERROR
		 * This is serious; we are left with the disabled
		 * keyboard intr.
		 */
		set_controller_command_byte(kbdc, 0xff, c);
		kbdc_lock(kbdc, FALSE);
		printf("atkbd: unable to enable the keyboard port and intr.\n");
		return EIO;
	}

	kbdc_lock(kbdc, FALSE);
	return 0;
}

static int
write_kbd(KBDC kbdc, int command, int data)
{
    int s;

    /* prevent the timeout routine from polling the keyboard */
    if (!kbdc_lock(kbdc, TRUE))
	return EBUSY;

    /* disable the keyboard and mouse interrupt */
    s = spltty();
#if 0
    c = get_controller_command_byte(kbdc);
    if ((c == -1)
	|| !set_controller_command_byte(kbdc,
            kbdc_get_device_mask(kbdc),
            KBD_DISABLE_KBD_PORT | KBD_DISABLE_KBD_INT
                | KBD_DISABLE_AUX_PORT | KBD_DISABLE_AUX_INT)) {
	/* CONTROLLER ERROR */
        kbdc_lock(kbdc, FALSE);
	splx(s);
	return EIO;
    }
    /*
     * Now that the keyboard controller is told not to generate
     * the keyboard and mouse interrupts, call `splx()' to allow
     * the other tty interrupts. The clock interrupt may also occur,
     * but the timeout routine (`scrn_timer()') will be blocked
     * by the lock flag set via `kbdc_lock()'
     */
    splx(s);
#endif

    if (send_kbd_command_and_data(kbdc, command, data) != KBD_ACK)
        send_kbd_command(kbdc, KBDC_ENABLE_KBD);

#if 0
    /* restore the interrupts */
    if (!set_controller_command_byte(kbdc,
            kbdc_get_device_mask(kbdc),
	    c & (KBD_KBD_CONTROL_BITS | KBD_AUX_CONTROL_BITS))) {
	/* CONTROLLER ERROR */
    }
#else
    splx(s);
#endif
    kbdc_lock(kbdc, FALSE);

    return 0;
}

static int
get_kbd_id(KBDC kbdc)
{
	int id1, id2;

	empty_both_buffers(kbdc, 10);
	id1 = id2 = -1;
	if (send_kbd_command(kbdc, KBDC_SEND_DEV_ID) != KBD_ACK)
		return -1;

	DELAY(10000); 	/* 10 msec delay */
	id1 = read_kbd_data(kbdc);
	if (id1 != -1)
		id2 = read_kbd_data(kbdc);

	if ((id1 == -1) || (id2 == -1)) {
		empty_both_buffers(kbdc, 10);
		test_controller(kbdc);
		test_kbd_port(kbdc);
		return -1;
	}
	return ((id2 << 8) | id1);
}

static int
typematic(int delay, int rate)
{
	static int delays[] = { 250, 500, 750, 1000 };
	static int rates[] = {  34,  38,  42,  46,  50,  55,  59,  63,
				68,  76,  84,  92, 100, 110, 118, 126,
			       136, 152, 168, 184, 200, 220, 236, 252,
			       272, 304, 336, 368, 400, 440, 472, 504 };
	int value;
	int i;

	for (i = sizeof(delays)/sizeof(delays[0]) - 1; i > 0; --i) {
		if (delay >= delays[i])
			break;
	}
	value = i << 5;
	for (i = sizeof(rates)/sizeof(rates[0]) - 1; i > 0; --i) {
		if (rate >= rates[i])
			break;
	}
	value |= i;
	return value;
}

#endif /* NATKBD > 0 */