/*      $NetBSD: gpib.c,v 1.26 2021/08/07 16:19:10 thorpej Exp $        */

/*-
 * Copyright (c) 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Gregory McGarry.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gpib.c,v 1.26 2021/08/07 16:19:10 thorpej Exp $");

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

#include <dev/gpib/gpibvar.h>

#include <dev/gpib/gpibio.h>            /* XXX */

#include "locators.h"

#ifndef DEBUG
#define DEBUG
#endif

#ifdef DEBUG
int gpibdebug = 0xff;
#define DBG_FOLLOW      0x01
#define DBG_INTR        0x02
#define DBG_FAIL        0x04
#define DPRINTF(mask, str)      if (gpibdebug & (mask)) printf str
#else
#define DPRINTF(mask, str)      /* nothing */
#endif

int     gpibmatch(device_t, cfdata_t, void *);
void    gpibattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(gpib, sizeof(struct gpib_softc),
        gpibmatch, gpibattach, NULL, NULL);

static int      gpibsubmatch1(device_t, cfdata_t, const int *, void *);
static int      gpibsubmatch2(device_t, cfdata_t, const int *, void *);
static int      gpibprint(void *, const char *);

dev_type_open(gpibopen);
dev_type_close(gpibclose);
dev_type_read(gpibread);
dev_type_write(gpibwrite);
dev_type_ioctl(gpibioctl);
dev_type_poll(gpibpoll);

const struct cdevsw gpib_cdevsw = {
        .d_open = gpibopen,
        .d_close = gpibclose,
        .d_read = gpibread,
        .d_write = gpibwrite,
        .d_ioctl = gpibioctl,
        .d_stop = nostop,
        .d_tty = notty,
        .d_poll = gpibpoll,
        .d_mmap = nommap,
        .d_kqfilter = nokqfilter,
        .d_discard = nodiscard,
        .d_flag = D_OTHER
};

extern struct cfdriver gpib_cd;

#define GPIBUNIT(dev)           (minor(dev) & 0x0f)

int gpibtimeout = 100000;       /* # of status tests before we give up */

int
gpibmatch(device_t parent, cfdata_t match, void *aux)
{

        return (1);
}

void
gpibattach(device_t parent, device_t self, void *aux)
{
        struct gpib_softc *sc = device_private(self);
        cfdata_t cf = device_cfdata(self);
        struct gpibdev_attach_args *gda = aux;
        struct gpib_attach_args ga;
        int address;

        sc->sc_dev = self;
        sc->sc_ic = gda->ga_ic;

        /*
         * If the configuration file specified a host address, then
         * use it in favour of registers/switches or the default (30).
         */
        if (cf->cf_loc[GPIBDEVCF_ADDRESS] != GPIBDEVCF_ADDRESS_DEFAULT)
                sc->sc_myaddr = cf->cf_loc[GPIBDEVCF_ADDRESS];
        else if (gda->ga_address != GPIBDEVCF_ADDRESS_DEFAULT)
                sc->sc_myaddr = gda->ga_address;
        else
                sc->sc_myaddr = 30;

        printf(": host address %d\n", sc->sc_myaddr);

        /* record our softc pointer */
        sc->sc_ic->bus = sc;

        /* Initialize the slave request queue */
        TAILQ_INIT(&sc->sc_queue);

        /* attach addressed devices */
        for (address=0; address<GPIB_NDEVS; address++) {
                ga.ga_ic = sc->sc_ic;
                ga.ga_address = address;
                config_search(sc->sc_dev, &ga,
                    CFARGS(.search = gpibsubmatch1));
        }

        /* attach the wild-carded devices - probably protocol busses */
        ga.ga_ic = sc->sc_ic;
        config_search(sc->sc_dev, &ga,
            CFARGS(.search = gpibsubmatch2));
}

int
gpibsubmatch1(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
{
        struct gpib_softc *sc = device_private(parent);
        struct gpib_attach_args *ga = aux;

        if (cf->cf_loc[GPIBCF_ADDRESS] != ga->ga_address)
                return (0);

        if (cf->cf_loc[GPIBCF_ADDRESS] == sc->sc_myaddr)
                return (0);

        if (config_probe(parent, cf, ga)) {
                if (gpib_alloc(sc, ga->ga_address))
                        return (0);
                config_attach(parent, cf, ga, gpibprint, CFARGS_NONE);
                return (0);
        }
        return (0);
}

int
gpibsubmatch2(device_t parent, cfdata_t cf, const int *ldesc, void *aux)
{
        struct gpib_attach_args *ga = aux;

        if (cf->cf_loc[GPIBCF_ADDRESS] != GPIBCF_ADDRESS_DEFAULT)
                return (0);

        ga->ga_address = GPIBCF_ADDRESS_DEFAULT;
        if (config_probe(parent, cf, ga)) {
                config_attach(parent, cf, ga, gpibdevprint, CFARGS_NONE);
                return (0);
        }
        return (0);
}

int
gpibprint(void *aux, const char *pnp)
{
        struct gpib_attach_args *ga = aux;

        if (ga->ga_address != GPIBCF_ADDRESS_DEFAULT)
                printf(" address %d", ga->ga_address);
        return (UNCONF);
}

int
gpibdevprint(void *aux, const char *pnp)
{

        if (pnp != NULL)
                printf("gpib at %s", pnp);
        return (UNCONF);
}

/*
 * Called by hardware driver, pass to device driver.
 */
int
gpibintr(void *v)
{
        struct gpib_softc *sc = v;
        gpib_handle_t hdl;

        DPRINTF(DBG_INTR, ("gpibintr: sc=%p\n", sc));

        hdl = TAILQ_FIRST(&sc->sc_queue);
        (hdl->hq_callback)(hdl->hq_softc, GPIBCBF_INTR);
        return (0);
}

/*
 * Create a callback handle.
 */
int
_gpibregister(struct gpib_softc *sc, int slave, gpib_callback_t callback,
    void *arg, gpib_handle_t *hdl)
{

        *hdl = malloc(sizeof(struct gpibqueue), M_DEVBUF, M_WAITOK);
        (*hdl)->hq_slave = slave;
        (*hdl)->hq_callback = callback;
        (*hdl)->hq_softc = arg;

        return (0);
}

/*
 * Request exclusive access to the GPIB bus.
 */
int
_gpibrequest(struct gpib_softc *sc, gpib_handle_t hdl)
{

        DPRINTF(DBG_FOLLOW, ("_gpibrequest: sc=%p hdl=%p\n", sc, hdl));

        TAILQ_INSERT_TAIL(&sc->sc_queue, hdl, hq_list);
        if (TAILQ_FIRST(&sc->sc_queue) == hdl)
                return (1);

        return (0);
}

/*
 * Release exclusive access to the GPIB bus.
 */
void
_gpibrelease(struct gpib_softc *sc, gpib_handle_t hdl)
{

        DPRINTF(DBG_FOLLOW, ("_gpibrelease: sc=%p hdl=%p\n", sc, hdl));

        TAILQ_REMOVE(&sc->sc_queue, hdl, hq_list);
        if ((hdl = TAILQ_FIRST(&sc->sc_queue)) != NULL)
                (*hdl->hq_callback)(hdl->hq_softc, GPIBCBF_START);
}


/*
 * Asynchronous wait.
 */
void
_gpibawait(struct gpib_softc *sc)
{
        int slave;

        DPRINTF(DBG_FOLLOW, ("_gpibawait: sc=%p\n", sc));

        slave = TAILQ_FIRST(&sc->sc_queue)->hq_slave;
        (*sc->sc_ic->ppwatch)(sc->sc_ic->cookie, slave);
}

/*
 * Synchronous (spin) wait.
 */
int
_gpibswait(struct gpib_softc *sc, int slave)
{
        int timo = gpibtimeout;
        int (*pptest)(void *, int);

        DPRINTF(DBG_FOLLOW, ("_gpibswait: sc=%p\n", sc));

        pptest = sc->sc_ic->pptest;
        while ((*pptest)(sc->sc_ic->cookie, slave) == 0) {
                if (--timo == 0) {
                        aprint_error_dev(sc->sc_dev, "swait timeout\n");
                        return(-1);
                }
        }
        return (0);
}

/*
 * Resource accounting: check if the address has already been
 * claimed and allocated.
 */
int
gpib_isalloc(struct gpib_softc *sc, u_int8_t address)
{

        DPRINTF(DBG_FOLLOW, ("gpib_isalloc: sc=%p address=%d\n", sc, address));

#ifdef DIAGNOSTIC
        if (address >= GPIB_NDEVS)
                panic("gpib_isalloc: device address out of range");
#endif

        return ((sc->sc_rmap & (1 << address)) != 0);
}

/*
 * Resource accounting: allocate the address.
 */
int
gpib_alloc(struct gpib_softc *sc, u_int8_t address)
{

        DPRINTF(DBG_FOLLOW, ("gpib_alloc: sc=%p address=%d\n", sc, address));

#ifdef DIAGNOSTIC
        if (address >= GPIB_NDEVS)
                panic("gpib_alloc: device address out of range");
#endif

        if (!gpib_isalloc(sc, address)) {
                sc->sc_rmap |= (1 << address);
                return (0);
        }
        return (1);
}

/*
 * Resource accounting: deallocate the address.
 */
void
gpib_dealloc(struct gpib_softc *sc, u_int8_t address)
{

        DPRINTF(DBG_FOLLOW, ("gpib_free: sc=%p address=%d\n", sc, address));

#ifdef DIAGNOSTIC
        if (address >= GPIB_NDEVS)
                panic("gpib_free: device address out of range");

        if (!gpib_isalloc(sc, address))
                panic("gpib_free: not allocated");
#endif

        sc->sc_rmap &= ~(1 << address);
}

int
_gpibsend(struct gpib_softc *sc, int slave, int sec, void *ptr, int origcnt)
{
        int rv;
        int cnt = 0;
        u_int8_t cmds[4];
        int i = 0;

        DPRINTF(DBG_FOLLOW,
            ("_gpibsend: sc=%p slave %d sec=%d ptr=%p cnt=%d\n",
            sc, slave, sec, ptr, origcnt));

        /*
         * For compatibility, call the hardware driver directly.
         */
        if (sc->sc_ic->send != NULL) {
                rv = (*sc->sc_ic->send)(sc->sc_ic->cookie,
                        slave, sec, ptr, origcnt);
                return (rv);
        }

        if ((*sc->sc_ic->tc)(sc->sc_ic->cookie, 0))
                goto senderror;
        cmds[i++] = GPIBCMD_UNL;
        cmds[i++] = GPIBCMD_TAG | sc->sc_myaddr;
        cmds[i++] = GPIBCMD_LAG | slave;
        if (sec >= 0 || sec == -2) {
                if (sec == -2)          /* selected device clear KLUDGE */
                        cmds[i++] = GPIBCMD_SDC;
                else
                        cmds[i++] = GPIBCMD_SCG | sec;
        }
        if ((*sc->sc_ic->sendcmds)(sc->sc_ic->cookie, cmds, i) != i)
                goto senderror;
        if ((*sc->sc_ic->gts)(sc->sc_ic->cookie))
                goto senderror;
        if (origcnt) {
                cnt = (*sc->sc_ic->senddata)(sc->sc_ic->cookie, ptr, origcnt);
                if (cnt != origcnt)
                        goto senderror;
                if ((*sc->sc_ic->tc)(sc->sc_ic->cookie, 0))
                        goto senderror;
        }
        return (origcnt);

senderror:
        (*sc->sc_ic->ifc)(sc->sc_ic->cookie);
        DPRINTF(DBG_FAIL,
            ("%s: _gpibsend failed: slave %d, sec %x, sent %d of %d bytes\n",
            device_xname(sc->sc_dev), slave, sec, cnt, origcnt));
        return (cnt);
}

int
_gpibrecv(struct gpib_softc *sc, int slave, int sec, void *ptr, int origcnt)
{
        int rv;
        u_int8_t cmds[4];
        int cnt = 0;
        int i = 0;

        DPRINTF(DBG_FOLLOW,
            ("_gpibrecv: sc=%p slave=%d sec=%d buf=%p cnt=%d\n",
            sc, slave, sec, ptr, origcnt));

        /*
         * For compatibility, call the hardware driver directly.
         */
        if (sc->sc_ic->recv != NULL) {
                rv = (*sc->sc_ic->recv)(sc->sc_ic->cookie,
                        slave, sec, ptr, origcnt);
                return (rv);
        }

        /*
         * slave < 0 implies continuation of a previous receive
         * that probably timed out.
         */
        if (slave >= 0) {
                if ((*sc->sc_ic->tc)(sc->sc_ic->cookie, 0))
                        goto recverror;
                cmds[i++] = GPIBCMD_UNL;
                cmds[i++] = GPIBCMD_LAG | sc->sc_myaddr;
                cmds[i++] = GPIBCMD_TAG | slave;
                if (sec >= 0)
                        cmds[i++] = GPIBCMD_SCG | sec;
                if ((*sc->sc_ic->sendcmds)(sc->sc_ic->cookie, cmds, i) != i)
                        goto recverror;
                if ((*sc->sc_ic->gts)(sc->sc_ic->cookie))
                        goto recverror;
        }
        if (origcnt) {
                cnt = (*sc->sc_ic->recvdata)(sc->sc_ic->cookie, ptr, origcnt);
                if (cnt != origcnt)
                        goto recverror;
                if ((sc->sc_ic->tc)(sc->sc_ic->cookie, 0))
                        goto recverror;
                cmds[0] = (slave == GPIB_BROADCAST_ADDR) ?
                    GPIBCMD_UNA : GPIBCMD_UNT;
                if ((*sc->sc_ic->sendcmds)(sc->sc_ic->cookie, cmds, 1) != 1)
                        goto recverror;
        }
        return (origcnt);

recverror:
        (*sc->sc_ic->ifc)(sc->sc_ic->cookie);
        DPRINTF(DBG_FAIL,
            ("_gpibrecv: failed, sc=%p slave %d, sec %x, got %d of %d bytes\n",
            sc, slave, sec, cnt, origcnt));
        return (cnt);
}

/*
 * /dev/gpib? interface
 */

int
gpibopen(dev_t dev, int flags, int mode, struct lwp *l)
{
        struct gpib_softc *sc;

        sc = device_lookup_private(&gpib_cd, GPIBUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(DBG_FOLLOW, ("gpibopen: sc=%p\n", sc));

        if (sc->sc_flags & GPIBF_ACTIVE)
                return (EBUSY);
        sc->sc_flags |= GPIBF_ACTIVE;

        return (0);
}

int
gpibclose(dev_t dev, int flag, int mode, struct lwp *l)
{
        struct gpib_softc *sc;

        sc = device_lookup_private(&gpib_cd, GPIBUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(DBG_FOLLOW, ("gpibclose: sc=%p\n", sc));

        sc->sc_flags &= ~GPIBF_ACTIVE;

        return (0);
}

int
gpibread(dev_t dev, struct uio *uio, int flags)
{
        struct gpib_softc *sc;

        sc = device_lookup_private(&gpib_cd, GPIBUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(DBG_FOLLOW, ("gpibread: sc=%p\n", sc));

        return (EOPNOTSUPP);
}

int
gpibwrite(dev_t dev, struct uio *uio, int flags)
{
        struct gpib_softc *sc;

        sc = device_lookup_private(&gpib_cd, GPIBUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(DBG_FOLLOW, ("gpibwrite: sc=%p\n", sc));

        return (EOPNOTSUPP);
}

int
gpibioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
{
        struct gpib_softc *sc;

        sc = device_lookup_private(&gpib_cd, GPIBUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(DBG_FOLLOW, ("gpibioctl(%lu, '%c',%lu): sc=%p\n",
            IOCPARM_LEN(cmd), (char)IOCGROUP(cmd), cmd & 0xff, sc));

        switch (cmd) {
        case GPIB_INFO:
                (*(int *)data) = 0xa5a5a5a5;
                break;
        }

        return (EINVAL);
}

int
gpibpoll(dev_t dev, int events, struct lwp *l)
{
        struct gpib_softc *sc;

        sc = device_lookup_private(&gpib_cd, GPIBUNIT(dev));
        if (sc == NULL)
                return (ENXIO);

        DPRINTF(DBG_FOLLOW, ("gpibpoll: sc=%p\n", sc));

        return (0);
}