/*      $NetBSD: mpu.c,v 1.19 2012/01/21 16:49:26 chs Exp $     */

/*
 * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (augustss@NetBSD.org) and by Andrew Doran.
 *
 * 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: mpu.c,v 1.19 2012/01/21 16:49:26 chs Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <sys/proc.h>
#include <sys/buf.h>

#include <sys/cpu.h>
#include <sys/intr.h>
#include <sys/bus.h>

#include <dev/midi_if.h>

#include <dev/ic/mpuvar.h>

#ifdef AUDIO_DEBUG
#define DPRINTF(x)      if (mpudebug) printf x
#define DPRINTFN(n,x)   if (mpudebug >= (n)) printf x
int     mpudebug = 0;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

#define MPU_DATA                0
#define MPU_COMMAND     1
#define  MPU_RESET      0xff
#define  MPU_UART_MODE  0x3f
#define  MPU_ACK                0xfe
#define MPU_STATUS      1
#define  MPU_OUTPUT_BUSY        0x40
#define  MPU_INPUT_EMPTY        0x80

#define MPU_MAXWAIT     10000   /* usec/10 to wait */

#define MPU_GETSTATUS(iot, ioh) (bus_space_read_1(iot, ioh, MPU_STATUS))

static int              mpu_reset(struct mpu_softc *);
static  inline int mpu_waitready(struct mpu_softc *);
static void             mpu_readinput(struct mpu_softc *);

static int      mpu_open(void *, int,
                         void (*iintr)(void *, int),
                         void (*ointr)(void *), void *arg);
static void     mpu_close(void *);
static int      mpu_output(void *, int);
static void     mpu_getinfo(void *, struct midi_info *);
static void     mpu_get_locks(void *, kmutex_t **, kmutex_t **);

const struct midi_hw_if mpu_midi_hw_if = {
        mpu_open,
        mpu_close,
        mpu_output,
        mpu_getinfo,
        0,                      /* ioctl */
        mpu_get_locks,
};

int
mpu_find(struct mpu_softc *sc)
{
        if (MPU_GETSTATUS(sc->iot, sc->ioh) == 0xff) {
                DPRINTF(("%s: No status\n", __func__));
                goto bad;
        }
        sc->open = 0;
        sc->intr = 0;
        if (mpu_reset(sc) == 0)
                return 1;
bad:
        return 0;
}

void
mpu_attach(struct mpu_softc *sc)
{

        if (sc->lock == NULL) {
                panic("mpu_attach: no lock");
        }

        midi_attach_mi(&mpu_midi_hw_if, sc, sc->sc_dev);
}

static inline int
mpu_waitready(struct mpu_softc *sc)
{
        int i;

        KASSERT(sc->lock == NULL || mutex_owned(sc->lock));

        for (i = 0; i < MPU_MAXWAIT; i++) {
                if (!(MPU_GETSTATUS(sc->iot, sc->ioh) & MPU_OUTPUT_BUSY))
                        return 0;
                delay(10);
        }
        return 1;
}

static int
mpu_reset(struct mpu_softc *sc)
{
        bus_space_tag_t iot = sc->iot;
        bus_space_handle_t ioh = sc->ioh;
        int i;

        KASSERT(sc->lock == NULL || mutex_owned(sc->lock));

        if (mpu_waitready(sc)) {
                DPRINTF(("%s: not ready\n", __func__));
                return EIO;
        }
        bus_space_write_1(iot, ioh, MPU_COMMAND, MPU_RESET);
        for (i = 0; i < 2*MPU_MAXWAIT; i++) {
                if (!(MPU_GETSTATUS(iot, ioh) & MPU_INPUT_EMPTY) &&
                    bus_space_read_1(iot, ioh, MPU_DATA) == MPU_ACK) {
                        return 0;
                }
        }
        DPRINTF(("%s: No ACK\n", __func__));
        return EIO;
}

static int
mpu_open(void *addr, int flags, void (*iintr)(void *, int),
    void (*ointr)(void *), void *arg)
{
        struct mpu_softc *sc = addr;

        DPRINTF(("%s: sc=%p\n", __func__, sc));

        KASSERT(mutex_owned(sc->lock));

        if (sc->open)
                return EBUSY;
#ifndef AUDIO_NO_POWER_CTL
        if (sc->powerctl)
                sc->powerctl(sc->powerarg, 1);
#endif
        if (mpu_reset(sc) != 0) {
#ifndef AUDIO_NO_POWER_CTL
                if (sc->powerctl)
                        sc->powerctl(sc->powerarg, 0);
#endif
                return EIO;
        }

        bus_space_write_1(sc->iot, sc->ioh, MPU_COMMAND, MPU_UART_MODE);
        sc->open = 1;
        sc->intr = iintr;
        sc->arg = arg;
        return 0;
}

static void
mpu_close(void *addr)
{
        struct mpu_softc *sc = addr;

        DPRINTF(("%s: sc=%p\n", __func__, sc));

        KASSERT(mutex_owned(sc->lock));

        sc->open = 0;
        sc->intr = 0;
        mpu_reset(sc); /* exit UART mode */

#ifndef AUDIO_NO_POWER_CTL
        if (sc->powerctl)
                sc->powerctl(sc->powerarg, 0);
#endif
}

static void
mpu_readinput(struct mpu_softc *sc)
{
        bus_space_tag_t iot = sc->iot;
        bus_space_handle_t ioh = sc->ioh;
        int data;

        KASSERT(mutex_owned(sc->lock));

        while(!(MPU_GETSTATUS(iot, ioh) & MPU_INPUT_EMPTY)) {
                data = bus_space_read_1(iot, ioh, MPU_DATA);
                DPRINTFN(3, ("%s: sc=%p 0x%02x\n", __func__, sc, data));
                if (sc->intr)
                        sc->intr(sc->arg, data);
        }
}

static int
mpu_output(void *addr, int d)
{
        struct mpu_softc *sc = addr;

        KASSERT(mutex_owned(sc->lock));

        DPRINTFN(3, ("%s: sc=%p 0x%02x\n", __func__, sc, d));
        if (!(MPU_GETSTATUS(sc->iot, sc->ioh) & MPU_INPUT_EMPTY)) {
                mpu_readinput(sc);
        }
        if (mpu_waitready(sc)) {
                DPRINTF(("%s:: not ready\n", __func__));
                return EIO;
        }
        bus_space_write_1(sc->iot, sc->ioh, MPU_DATA, d);
        return 0;
}

static void
mpu_getinfo(void *addr, struct midi_info *mi)
{
        struct mpu_softc *sc = addr;

        KASSERT(mutex_owned(sc->lock));

        mi->name = sc->model;
        mi->props = 0;
}

static void
mpu_get_locks(void *addr, kmutex_t **intr, kmutex_t **proc)
{
        struct mpu_softc *sc = addr;

        *intr = sc->lock;
        *proc = NULL;
}

int
mpu_intr(void *addr)
{
        struct mpu_softc *sc = addr;

        KASSERT(mutex_owned(sc->lock));

        if (MPU_GETSTATUS(sc->iot, sc->ioh) & MPU_INPUT_EMPTY) {
                DPRINTF(("%s: no data\n", __func__));
                return 0;
        } else {
                mpu_readinput(sc);
                return 1;
        }
}