/*      $NetBSD: ams.c,v 1.31 2021/08/07 16:18:57 thorpej Exp $ */

/*
 * Copyright (C) 1998   Colin Wood
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Colin Wood.
 * 4. 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 ``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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ams.c,v 1.31 2021/08/07 16:18:57 thorpej Exp $");

#include <sys/param.h>
#include <sys/device.h>
#include <sys/fcntl.h>
#include <sys/poll.h>
#include <sys/select.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/sysctl.h>

#include <machine/autoconf.h>

#include <dev/wscons/wsconsio.h>
#include <dev/wscons/wsmousevar.h>

#include <macppc/dev/adbvar.h>
#include <macppc/dev/aedvar.h>
#include <macppc/dev/amsvar.h>

#include "aed.h"

/*
 * Function declarations.
 */
static int      amsmatch(device_t, cfdata_t, void *);
static void     amsattach(device_t, device_t, void *);
static void     ems_init(struct ams_softc *);
static void     ms_processevent(adb_event_t *event, struct ams_softc *);
static void     init_trackpad(struct ams_softc *);

/* Driver definition. */
CFATTACH_DECL_NEW(ams, sizeof(struct ams_softc),
    amsmatch, amsattach, NULL, NULL);

int ams_enable(void *);
int ams_ioctl(void *, u_long, void *, int, struct lwp *);
void ams_disable(void *);

/*
 * handle tapping the trackpad
 * different pads report different button counts and use slightly different
 * protocols
 */
static void ams_mangle_2(struct ams_softc *, int);
static void ams_mangle_4(struct ams_softc *, int);
static int  sysctl_ams_tap(SYSCTLFN_ARGS);

const struct wsmouse_accessops ams_accessops = {
        ams_enable,
        ams_ioctl,
        ams_disable,
};

static int
amsmatch(device_t parent, cfdata_t cf, void *aux)
{
        struct adb_attach_args *aa_args = aux;

        if (aa_args->origaddr == ADBADDR_MS)
                return 1;
        else
                return 0;
}

static void
amsattach(device_t parent, device_t self, void *aux)
{
        ADBSetInfoBlock adbinfo;
        struct ams_softc *sc = device_private(self);
        struct adb_attach_args *aa_args = aux;
        int error;
        struct wsmousedev_attach_args a;

        sc->sc_dev = self;
        sc->origaddr = aa_args->origaddr;
        sc->adbaddr = aa_args->adbaddr;
        sc->handler_id = aa_args->handler_id;

        sc->sc_class = MSCLASS_MOUSE;
        sc->sc_buttons = 1;
        sc->sc_res = 100;
        sc->sc_devid[0] = 0;
        sc->sc_devid[4] = 0;

        adbinfo.siServiceRtPtr = (Ptr)ms_adbcomplete;
        adbinfo.siDataAreaAddr = (void *)sc;

        ems_init(sc);

        /* print out the type of mouse we have */
        switch (sc->handler_id) {
        case ADBMS_100DPI:
                printf("%d-button, %d dpi mouse\n", sc->sc_buttons,
                    (int)(sc->sc_res));
                break;
        case ADBMS_200DPI:
                sc->sc_res = 200;
                printf("%d-button, %d dpi mouse\n", sc->sc_buttons,
                    (int)(sc->sc_res));
                break;
        case ADBMS_MSA3:
                printf("Mouse Systems A3 mouse, %d-button, %d dpi\n",
                    sc->sc_buttons, (int)(sc->sc_res));
                break;
        case ADBMS_USPEED:
                printf("MicroSpeed mouse, default parameters\n");
                break;
        case ADBMS_UCONTOUR:
                printf("Contour mouse, default parameters\n");
                break;
        case ADBMS_TURBO:
                printf("Kensington Turbo Mouse\n");
                break;
        case ADBMS_EXTENDED:
                if (sc->sc_devid[0] == '\0') {
                        printf("Logitech ");
                        switch (sc->sc_class) {
                        case MSCLASS_MOUSE:
                                printf("MouseMan (non-EMP) mouse");
                                break;
                        case MSCLASS_TRACKBALL:
                                printf("TrackMan (non-EMP) trackball");
                                break;
                        default:
                                printf("non-EMP relative positioning device");
                                break;
                        }
                        printf("\n");
                } else {
                        printf("EMP ");
                        switch (sc->sc_class) {
                        case MSCLASS_TABLET:
                                printf("tablet");
                                break;
                        case MSCLASS_MOUSE:
                                printf("mouse");
                                break;
                        case MSCLASS_TRACKBALL:
                                printf("trackball");
                                break;
                        case MSCLASS_TRACKPAD:
                                printf("trackpad");
                                init_trackpad(sc);
                                break;
                        default:
                                printf("unknown device");
                                break;
                        }
                        printf(" <%s> %d-button, %d dpi\n", sc->sc_devid,
                            sc->sc_buttons, (int)(sc->sc_res));
                }
                break;
        default:
                printf("relative positioning device (mouse?) (%d)\n",
                        sc->handler_id);
                break;
        }
        error = SetADBInfo(&adbinfo, sc->adbaddr);
#ifdef ADB_DEBUG
        if (adb_debug)
                printf("ams: returned %d from SetADBInfo\n", error);
#endif

        a.accessops = &ams_accessops;
        a.accesscookie = sc;
        sc->sc_wsmousedev = config_found(self, &a, wsmousedevprint, CFARGS_NONE);
}


/*
 * Initialize extended mouse support -- probes devices as described
 * in Inside Macintosh: Devices, Chapter 5 "ADB Manager".
 *
 * Extended Mouse Protocol is documented in TechNote HW1:
 *      "ADB - The Untold Story:  Space Aliens Ate My Mouse"
 *
 * Supports: Extended Mouse Protocol, MicroSpeed Mouse Deluxe,
 *           Mouse Systems A^3 Mouse, Logitech non-EMP MouseMan
 */
void
ems_init(struct ams_softc *sc)
{
        int adbaddr;
        short cmd;
        u_char buffer[9];

        adbaddr = sc->adbaddr;
        if (sc->origaddr != ADBADDR_MS)
                return;
        if (sc->handler_id == ADBMS_USPEED ||
            sc->handler_id == ADBMS_UCONTOUR) {
                /* Found MicroSpeed Mouse Deluxe Mac or Contour Mouse */
                cmd = ADBLISTEN(adbaddr, 1);

                /*
                 * To setup the MicroSpeed or the Contour, it appears
                 * that we can send the following command to the mouse
                 * and then expect data back in the form:
                 *  buffer[0] = 4 (bytes)
                 *  buffer[1], buffer[2] as std. mouse
                 *  buffer[3] = buffer[4] = 0xff when no buttons
                 *   are down.  When button N down, bit N is clear.
                 * buffer[4]'s locking mask enables a
                 * click to toggle the button down state--sort of
                 * like the "Easy Access" shift/control/etc. keys.
                 * buffer[3]'s alternative speed mask enables using
                 * different speed when the corr. button is down
                 */
                buffer[0] = 4;
                buffer[1] = 0x00;       /* Alternative speed */
                buffer[2] = 0x00;       /* speed = maximum */
                buffer[3] = 0x10;       /* enable extended protocol,
                                         * lower bits = alt. speed mask
                                         *            = 0000b
                                         */
                buffer[4] = 0x07;       /* Locking mask = 0000b,
                                         * enable buttons = 0111b
                                         */
                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

                sc->sc_buttons = 3;
                sc->sc_res = 200;
                return;
        }
        if (sc->handler_id == ADBMS_TURBO) {
                /* Found Kensington Turbo Mouse */
                static u_char data1[] =
                        { 8, 0xe7, 0x8c, 0, 0, 0, 0xff, 0xff, 0x94 };
                static u_char data2[] =
                        { 8, 0xa5, 0x14, 0, 0, 0x69, 0xff, 0xff, 0x27 };

                buffer[0] = 0;
                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, ADBFLUSH(adbaddr));

                adb_op_sync((Ptr)data1, NULL, (Ptr)0, ADBLISTEN(adbaddr, 2));

                buffer[0] = 0;
                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, ADBFLUSH(adbaddr));

                adb_op_sync((Ptr)data2, NULL, (Ptr)0, ADBLISTEN(adbaddr, 2));
                return;
        }
        if ((sc->handler_id == ADBMS_100DPI) ||
            (sc->handler_id == ADBMS_200DPI)) {
                /* found a mouse */
                cmd = ADBTALK(adbaddr, 3);
                if (adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd)) {
#ifdef ADB_DEBUG
                        if (adb_debug)
                                printf("adb: ems_init timed out\n");
#endif
                        return;
                }

                /* Attempt to initialize Extended Mouse Protocol */
                buffer[2] = 4; /* make handler ID 4 */
                cmd = ADBLISTEN(adbaddr, 3);
                if (adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd)) {
#ifdef ADB_DEBUG
                        if (adb_debug)
                                printf("adb: ems_init timed out\n");
#endif
                        return;
                }

                /*
                 * Check to see if successful, if not
                 * try to initialize it as other types
                 */
                cmd = ADBTALK(adbaddr, 3);
                if (adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd) == 0 &&
                    buffer[2] == ADBMS_EXTENDED) {
                        sc->handler_id = ADBMS_EXTENDED;
                        cmd = ADBTALK(adbaddr, 1);
                        if (adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd)) {
#ifdef ADB_DEBUG
                                if (adb_debug)
                                        printf("adb: ems_init timed out\n");
#endif
                        } else if (buffer[0] == 8) {
                                /* we have a true EMP device */
#ifdef ADB_PRINT_EMP
                                printf("EMP: %02x %02x %02x %02x %02x %02x %02x %02x\n",
                                    buffer[1], buffer[2], buffer[3], buffer[4],
                                    buffer[5], buffer[6], buffer[7], buffer[8]);
#endif
                                sc->sc_class = buffer[7];
                                sc->sc_buttons = buffer[8];
                                sc->sc_res = (int)*(short *)&buffer[5];
                                memcpy(sc->sc_devid, &(buffer[1]), 4);
                        } else if (buffer[1] == 0x9a &&
                            ((buffer[2] == 0x20) || (buffer[2] == 0x21))) {
                                /*
                                 * Set up non-EMP Mouseman/Trackman to put
                                 * button bits in 3rd byte instead of sending
                                 * via pseudo keyboard device.
                                 */
                                cmd = ADBLISTEN(adbaddr, 1);
                                buffer[0]=2;
                                buffer[1]=0x00;
                                buffer[2]=0x81;
                                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

                                cmd = ADBLISTEN(adbaddr, 1);
                                buffer[0]=2;
                                buffer[1]=0x01;
                                buffer[2]=0x81;
                                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

                                cmd = ADBLISTEN(adbaddr, 1);
                                buffer[0]=2;
                                buffer[1]=0x02;
                                buffer[2]=0x81;
                                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

                                cmd = ADBLISTEN(adbaddr, 1);
                                buffer[0]=2;
                                buffer[1]=0x03;
                                buffer[2]=0x38;
                                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

                                sc->sc_buttons = 3;
                                sc->sc_res = 400;
                                if (buffer[2] == 0x21)
                                        sc->sc_class = MSCLASS_TRACKBALL;
                                else
                                        sc->sc_class = MSCLASS_MOUSE;
                        } else
                                /* unknown device? */;
                } else {
                        /* Attempt to initialize as an A3 mouse */
                        buffer[2] = 0x03; /* make handler ID 3 */
                        cmd = ADBLISTEN(adbaddr, 3);
                        if (adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd)) {
#ifdef ADB_DEBUG
                                if (adb_debug)
                                        printf("adb: ems_init timed out\n");
#endif
                                return;
                        }

                        /*
                         * Check to see if successful, if not
                         * try to initialize it as other types
                         */
                        cmd = ADBTALK(adbaddr, 3);
                        if (adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd) == 0
                            && buffer[2] == ADBMS_MSA3) {
                                sc->handler_id = ADBMS_MSA3;
                                /* Initialize as above */
                                cmd = ADBLISTEN(adbaddr, 2);
                                /* listen 2 */
                                buffer[0] = 3;
                                buffer[1] = 0x00;
                                /* Irrelevant, buffer has 0x77 */
                                buffer[2] = 0x07;
                                /*
                                 * enable 3 button mode = 0111b,
                                 * speed = normal
                                 */
                                adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);
                                sc->sc_buttons = 3;
                                sc->sc_res = 300;
                        } else {
                                /* No special support for this mouse */
                        }
                }
        }
}

/*
 * Handle putting the mouse data received from the ADB into
 * an ADB event record.
 */
void
ms_adbcomplete(uint8_t *buffer, uint8_t *data_area, int adb_command)
{
        adb_event_t event;
        struct ams_softc *sc;
        int adbaddr;
#ifdef ADB_DEBUG
        int i;

        if (adb_debug)
                printf("adb: transaction completion\n");
#endif

        adbaddr = ADB_CMDADDR(adb_command);
        sc = (struct ams_softc *)data_area;

        if ((sc->handler_id == ADBMS_EXTENDED) && (sc->sc_devid[0] == 0)) {
                /* massage the data to look like EMP data */
                if ((buffer[3] & 0x04) == 0x04)
                        buffer[1] &= 0x7f;
                else
                        buffer[1] |= 0x80;
                if ((buffer[3] & 0x02) == 0x02)
                        buffer[2] &= 0x7f;
                else
                        buffer[2] |= 0x80;
                if ((buffer[3] & 0x01) == 0x01)
                        buffer[3] = 0x00;
                else
                        buffer[3] = 0x80;
        }

        event.addr = adbaddr;
        event.hand_id = sc->handler_id;
        event.def_addr = sc->origaddr;
        event.byte_count = buffer[0];
        memcpy(event.bytes, buffer + 1, event.byte_count);

#ifdef ADB_DEBUG
        if (adb_debug) {
                printf("ams: from %d at %d (org %d) %d:", event.addr,
                    event.hand_id, event.def_addr, buffer[0]);
                for (i = 1; i <= buffer[0]; i++)
                        printf(" %x", buffer[i]);
                printf("\n");
        }
#endif

        microtime(&event.timestamp);

        ms_processevent(&event, sc);
}

/*
 * Given a mouse ADB event, record the button settings, calculate the
 * x- and y-axis motion, and handoff the event to the appropriate subsystem.
 */
static void
ms_processevent(adb_event_t *event, struct ams_softc *sc)
{
        adb_event_t new_event;
        int i, button_bit, max_byte, mask, buttons, dx, dy;

        new_event = *event;
        buttons = 0;

        /*
         * This should handle both plain ol' Apple mice and mice
         * that claim to support the Extended Apple Mouse Protocol.
         */
        max_byte = event->byte_count;
        button_bit = 1;
        switch (event->hand_id) {
        case ADBMS_USPEED:
        case ADBMS_UCONTOUR:
                /* MicroSpeed mouse and Contour mouse */
                if (max_byte == 4)
                        buttons = (~event->bytes[2]) & 0xff;
                else
                        buttons = (event->bytes[0] & 0x80) ? 0 : 1;
                break;
        case ADBMS_MSA3:
                /* Mouse Systems A3 mouse */
                if (max_byte == 3)
                        buttons = (~event->bytes[2]) & 0x07;
                else
                        buttons = (event->bytes[0] & 0x80) ? 0 : 1;
                break;
        default:        
                /* Classic Mouse Protocol (up to 2 buttons) */
                for (i = 0; i < 2; i++, button_bit <<= 1)
                        /* 0 when button down */
                        if (!(event->bytes[i] & 0x80))
                                buttons |= button_bit;
                        else
                                buttons &= ~button_bit;
                /* Extended Protocol (up to 6 more buttons) */
                for (mask = 0x80; i < max_byte;
                     i += (mask == 0x80), button_bit <<= 1) {
                        /* 0 when button down */
                        if (!(event->bytes[i] & mask))
                                buttons |= button_bit;
                        else
                                buttons &= ~button_bit;
                        mask = ((mask >> 4) & 0xf)
                                | ((mask & 0xf) << 4);
                }                               
                break;
        }

        dx = ((int)(event->bytes[1] & 0x3f)) -
                                ((event->bytes[1] & 0x40) ? 64 : 0);
        dy = ((int) (event->bytes[0] & 0x3f)) -
                                ((event->bytes[0] & 0x40) ? 64 : 0);

        if (sc->sc_class == MSCLASS_TRACKPAD) {
                if (sc->sc_tapping == 1) {

                        if (sc->sc_down) {
                                /* finger is down - collect motion data */
                                sc->sc_x += dx;
                                sc->sc_y += dy;
                        }
                        switch (sc->sc_buttons) {
                                case 2:
                                        ams_mangle_2(sc, buttons);
                                        break;
                                case 4:
                                        ams_mangle_4(sc, buttons);
                                        break;
                        }
                }
                /* filter the pseudo-buttons out */
                buttons &= 1;
        }

        new_event.u.m.buttons = sc->sc_mb | buttons;
        new_event.u.m.dx = dx;
        new_event.u.m.dy = dy;

        if (sc->sc_wsmousedev)
                wsmouse_input(sc->sc_wsmousedev, new_event.u.m.buttons,
                              new_event.u.m.dx, -new_event.u.m.dy, 0, 0,
                              WSMOUSE_INPUT_DELTA);
#if NAED > 0
        aed_input(&new_event);
#endif
}

static void
ams_mangle_2(struct ams_softc *sc, int buttons)
{

        if (buttons & 4) {
                /* finger down on pad */
                if (sc->sc_down == 0) {
                        sc->sc_down = 1;
                        sc->sc_x = 0;
                        sc->sc_y = 0;
                }
        }
        if (buttons & 8) {
                /* finger up */
                if (sc->sc_down) {
                        if (((sc->sc_x * sc->sc_x + 
                            sc->sc_y * sc->sc_y) < 20) && 
                            (sc->sc_wsmousedev)) {
                                /* 
                                 * if there wasn't much movement between
                                 * finger down and up again we assume
                                 * someone tapped the pad and we just
                                 * send a mouse button event
                                 */
                                wsmouse_input(sc->sc_wsmousedev,
                                    1, 0, 0, 0, 0, WSMOUSE_INPUT_DELTA);
                        }
                        sc->sc_down = 0;
                }
        }
}

static void
ams_mangle_4(struct ams_softc *sc, int buttons)
{

        if (buttons & 0x20) {
                /* finger down on pad */
                if (sc->sc_down == 0) {
                        sc->sc_down = 1;
                        sc->sc_x = 0;
                        sc->sc_y = 0;
                }
        }
        if ((buttons & 0x20) == 0) {
                /* finger up */
                if (sc->sc_down) {
                        if (((sc->sc_x * sc->sc_x + 
                            sc->sc_y * sc->sc_y) < 20) && 
                            (sc->sc_wsmousedev)) {
                                /* 
                                 * if there wasn't much movement between
                                 * finger down and up again we assume
                                 * someone tapped the pad and we just
                                 * send a mouse button event
                                 */
                                wsmouse_input(sc->sc_wsmousedev,
                                    1, 0, 0, 0, 0, WSMOUSE_INPUT_DELTA);
                        }
                        sc->sc_down = 0;
                }
        }
}

int
ams_enable(void *v)
{
        return 0;
}

int
ams_ioctl(void *v, u_long cmd, void *data, int flag, struct lwp *l)
{

        switch (cmd) {
        case WSMOUSEIO_GTYPE:
                *(u_int *)data = WSMOUSE_TYPE_ADB;
                break;
        }
        return EPASSTHROUGH;
}

void
ams_disable(void *v)
{
}

static void
init_trackpad(struct ams_softc *sc)
{
        struct sysctlnode *me = NULL, *node = NULL;
        int cmd, res, ret;
        u_char buffer[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
        u_char b2[10];
        u_char b3[9] = {8, 0x99, 0x94, 0x19, 0xff, 0xb2, 0x8a, 0x1b, 0x50};
        
        cmd = ADBTALK(sc->adbaddr, 1);
        res = adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

        if (buffer[0] != 8)
                return;

        /* now whack the pad */
        cmd = ADBLISTEN(sc->adbaddr, 1);
        memcpy(b2, buffer, 10);
        b2[7] = 0x0d;
        adb_op_sync((Ptr)b2, NULL, (Ptr)0, cmd);

        cmd = ADBLISTEN(sc->adbaddr, 2);
        adb_op_sync((Ptr)b3, NULL, (Ptr)0, cmd);

        cmd = ADBLISTEN(sc->adbaddr, 1);
        b2[7] = 0x03;
        adb_op_sync((Ptr)b2, NULL, (Ptr)0, cmd);

        buffer[0] = 0;
        cmd = ADBFLUSH(sc->adbaddr);
        adb_op_sync((Ptr)buffer, NULL, (Ptr)0, cmd);

        /*
         * setup a sysctl node to control whether tapping the pad should
         * trigger mouse button events
         */

        sc->sc_tapping = 1;
        
        ret = sysctl_createv(NULL, 0, NULL, (const struct sysctlnode **)&me,
            CTLFLAG_READWRITE,
            CTLTYPE_NODE, device_xname(sc->sc_dev), NULL,
            NULL, 0, NULL, 0,
            CTL_MACHDEP, CTL_CREATE, CTL_EOL);

        ret=sysctl_createv(NULL, 0, NULL, (const struct sysctlnode **)&node,
            CTLFLAG_READWRITE | CTLFLAG_OWNDESC | CTLFLAG_IMMEDIATE,
            CTLTYPE_INT, "tapping", "tapping the pad causes button events",
            sysctl_ams_tap, 1, NULL, 0,
            CTL_MACHDEP, me->sysctl_num, CTL_CREATE, CTL_EOL);
        if (node != NULL) {
                node->sysctl_data = sc;
        }       
}

static int
sysctl_ams_tap(SYSCTLFN_ARGS)
{
        struct sysctlnode node = *rnode;
        struct ams_softc *sc = node.sysctl_data;

        node.sysctl_idata = sc->sc_tapping;

        if (newp) {

                /* we're asked to write */      
                node.sysctl_data = &sc->sc_tapping;
                if (sysctl_lookup(SYSCTLFN_CALL(&node)) == 0) {

                        sc->sc_tapping = (node.sysctl_idata == 0) ? 0 : 1;
                        return 0;
                }
                return EINVAL;
        } else {

                node.sysctl_size = 4;
                return (sysctl_lookup(SYSCTLFN_CALL(&node)));
        }

        return 0;
}

SYSCTL_SETUP(sysctl_ams_setup, "sysctl ams subtree setup")
{

        sysctl_createv(NULL, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "machdep", NULL,
                       NULL, 0, NULL, 0,
                       CTL_MACHDEP, CTL_EOL);
}