/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright 2008 by Marco Trillo. 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.
 *
 * 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.
 */

/*
 *      Apple Onboard Audio (AOA).
 */

#include <sys/cdefs.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <machine/dbdma.h>
#include <machine/resource.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <dev/ofw/ofw_bus.h>

#ifdef HAVE_KERNEL_OPTION_HEADERS
#include "opt_snd.h"
#endif

#include <dev/sound/pcm/sound.h>
#include <dev/sound/macio/aoa.h>

#include "mixer_if.h"

struct aoa_dma {
        struct mtx               mutex;
        struct resource         *reg;           /* DBDMA registers */
        dbdma_channel_t         *channel;       /* DBDMA channel */
        bus_dma_tag_t            tag;           /* bus_dma tag */
        struct pcm_channel      *pcm;           /* PCM channel */
        struct snd_dbuf         *buf;           /* PCM buffer */
        unsigned int                     slots;         /* # of slots */
        unsigned int                     slot;          /* current slot */
        unsigned int                     bufsz;         /* buffer size */
        unsigned int                     blksz;         /* block size */
        int                      running;
};

static void
aoa_dma_set_program(struct aoa_dma *dma)
{
        uint32_t                 addr;
        int                      i;

        addr = (uint32_t)dma->buf->buf_addr;
        KASSERT(dma->bufsz == dma->buf->bufsize, ("bad size"));

        dma->slots = dma->bufsz / dma->blksz;

        for (i = 0; i < dma->slots; ++i) {
                dbdma_insert_command(dma->channel, 
                    i, /* slot */
                    DBDMA_OUTPUT_MORE, /* command */
                    0, /* stream */
                    addr, /* data */
                    dma->blksz, /* count */
                    DBDMA_ALWAYS, /* interrupt */
                    DBDMA_COND_TRUE, /* branch */
                    DBDMA_NEVER, /* wait */
                    dma->slots + 1 /* branch_slot */
                );

                addr += dma->blksz;
        }

        /* Branch back to beginning. */
        dbdma_insert_branch(dma->channel, dma->slots, 0);

        /* STOP command to branch when S0 is asserted. */
        dbdma_insert_stop(dma->channel, dma->slots + 1);

        /* Set S0 as the condition to branch to STOP. */
        dbdma_set_branch_selector(dma->channel, 1 << 0, 1 << 0);
        dbdma_set_device_status(dma->channel, 1 << 0, 0);

        dbdma_sync_commands(dma->channel, BUS_DMASYNC_PREWRITE);
}

#define AOA_BUFFER_SIZE         65536

static struct aoa_dma * 
aoa_dma_create(struct aoa_softc *sc)
{
        struct aoa_dma *dma;
        bus_dma_tag_t   tag;
        int             err;
        device_t        self;

        self = sc->sc_dev;
        err = bus_dma_tag_create(bus_get_dma_tag(self), 
            4, 0, BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL, NULL, 
            AOA_BUFFER_SIZE, 1, AOA_BUFFER_SIZE, 0, NULL, NULL, &tag);
        if (err != 0) 
                return (NULL);

        dma = malloc(sizeof(*dma), M_DEVBUF, M_WAITOK | M_ZERO);
        dma->tag = tag;
        dma->bufsz = AOA_BUFFER_SIZE;
        dma->blksz = PAGE_SIZE; /* initial blocksize */

        mtx_init(&dma->mutex, "AOA", NULL, MTX_DEF);

        sc->sc_intrp = dma;

        return (dma);
}

static void
aoa_dma_delete(struct aoa_dma *dma)
{
        bus_dma_tag_destroy(dma->tag);
        mtx_destroy(&dma->mutex);
        free(dma, M_DEVBUF);
}

static uint32_t
aoa_chan_setblocksize(kobj_t obj, void *data, uint32_t blocksz)
{
        struct aoa_dma          *dma = data;
        int                      err, lz;

        DPRINTF(("aoa_chan_setblocksize: blocksz = %u, dma->blksz = %u\n", 
                blocksz, dma->blksz));
        KASSERT(!dma->running, ("dma is running"));
        KASSERT(blocksz > 0, ("bad blocksz"));

        /* Round blocksz down to a power of two... */
        __asm volatile ("cntlzw %0,%1" : "=r"(lz) : "r"(blocksz));
        blocksz = 1 << (31 - lz);
        DPRINTF(("blocksz = %u\n", blocksz));

        /* ...but no more than the buffer. */
        if (blocksz > dma->bufsz)
                blocksz = dma->bufsz;

        err = sndbuf_resize(dma->buf, dma->bufsz / blocksz, blocksz);
        if (err != 0) {
                DPRINTF(("sndbuf_resize returned %d\n", err));
                return (0);
        }

        if (blocksz == dma->blksz)
                return (dma->blksz);

        /* One slot per block plus branch to 0 plus STOP. */
        err = dbdma_resize_channel(dma->channel, 2 + dma->bufsz / blocksz);
        if (err != 0) {
                DPRINTF(("dbdma_resize_channel returned %d\n", err));
                return (0);
        }

        /* Set the new blocksize. */
        dma->blksz = blocksz;
        aoa_dma_set_program(dma);

        return (dma->blksz);
}

static int
aoa_chan_setformat(kobj_t obj, void *data, uint32_t format)
{
        DPRINTF(("aoa_chan_setformat: format = %u\n", format));

        if (format != SND_FORMAT(AFMT_S16_BE, 2, 0))
                return (EINVAL);

        return (0);
}

static uint32_t
aoa_chan_setspeed(kobj_t obj, void *data, uint32_t speed)
{
        DPRINTF(("aoa_chan_setspeed: speed = %u\n", speed));

        return (44100);
}

static uint32_t
aoa_chan_getptr(kobj_t obj, void *data)
{
        struct aoa_dma   *dma = data;

        if (!dma->running)
                return (0);

        return (dma->slot * dma->blksz);
}

static void *
aoa_chan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b, 
        struct pcm_channel *c, int dir)
{
        struct aoa_softc        *sc = devinfo;
        struct aoa_dma          *dma;
        int                      max_slots, err;

        KASSERT(dir == PCMDIR_PLAY, ("bad dir"));

        dma = aoa_dma_create(sc);
        if (!dma)
                return (NULL);
        dma->pcm = c;
        dma->buf = b;
        dma->reg = sc->sc_odma;

        /* One slot per block, plus branch to 0 plus STOP. */
        max_slots = 2 + dma->bufsz / dma->blksz;
        err = dbdma_allocate_channel(dma->reg, 0, bus_get_dma_tag(sc->sc_dev),
            max_slots, &dma->channel );
        if (err != 0) {
                aoa_dma_delete(dma);
                return (NULL);
        }

        if (sndbuf_alloc(dma->buf, dma->tag, 0, dma->bufsz) != 0) {
                dbdma_free_channel(dma->channel);
                aoa_dma_delete(dma);
                return (NULL);
        }

        aoa_dma_set_program(dma);

        return (dma);
}

static int
aoa_chan_trigger(kobj_t obj, void *data, int go)
{
        struct aoa_dma  *dma = data;
        int              i;

        switch (go) {
        case PCMTRIG_START:

                /* Start the DMA. */
                dma->running = 1;
                
                dma->slot = 0;
                dbdma_set_current_cmd(dma->channel, dma->slot);

                dbdma_run(dma->channel);

                return (0);

        case PCMTRIG_STOP:
        case PCMTRIG_ABORT:
                
                mtx_lock(&dma->mutex);

                dma->running = 0;

                /* Make it branch to the STOP command. */
                dbdma_set_device_status(dma->channel, 1 << 0, 1 << 0);

                /* XXX should wait for DBDMA_ACTIVE to clear. */
                DELAY(40000);

                /* Reset the DMA. */
                dbdma_stop(dma->channel);
                dbdma_set_device_status(dma->channel, 1 << 0, 0);

                for (i = 0; i < dma->slots; ++i)
                        dbdma_clear_cmd_status(dma->channel, i);

                mtx_unlock(&dma->mutex);

                return (0);
        }

        return (0);
}

static int
aoa_chan_free(kobj_t obj, void *data)
{
        struct aoa_dma  *dma = data;

        sndbuf_free(dma->buf);
        dbdma_free_channel(dma->channel);
        aoa_dma_delete(dma);

        return (0);
}

void 
aoa_interrupt(void *xsc)
{
        struct aoa_softc        *sc = xsc;
        struct aoa_dma          *dma;

        if (!(dma = sc->sc_intrp) || !dma->running)
                return;

        mtx_lock(&dma->mutex);

        while (dbdma_get_cmd_status(dma->channel, dma->slot)) {
                dbdma_clear_cmd_status(dma->channel, dma->slot);
                dma->slot = (dma->slot + 1) % dma->slots;

                mtx_unlock(&dma->mutex);
                chn_intr(dma->pcm);
                mtx_lock(&dma->mutex);
        }

        mtx_unlock(&dma->mutex);
}

static uint32_t sc_fmt[] = {
        SND_FORMAT(AFMT_S16_BE, 2, 0),
        0
};
static struct pcmchan_caps aoa_caps = {44100, 44100, sc_fmt, 0};

static struct pcmchan_caps *
aoa_chan_getcaps(kobj_t obj, void *data)
{
        return (&aoa_caps);
}

static kobj_method_t aoa_chan_methods[] = {
        KOBJMETHOD(channel_init,        aoa_chan_init),
        KOBJMETHOD(channel_free,        aoa_chan_free),
        KOBJMETHOD(channel_setformat,   aoa_chan_setformat),
        KOBJMETHOD(channel_setspeed,    aoa_chan_setspeed),
        KOBJMETHOD(channel_setblocksize,aoa_chan_setblocksize),
        KOBJMETHOD(channel_trigger,     aoa_chan_trigger),
        KOBJMETHOD(channel_getptr,      aoa_chan_getptr),
        KOBJMETHOD(channel_getcaps,     aoa_chan_getcaps),
        KOBJMETHOD_END
};
CHANNEL_DECLARE(aoa_chan);

int
aoa_attach(void *xsc)
{
        char status[SND_STATUSLEN];
        struct aoa_softc *sc;
        device_t self;
        int err __unused;

        sc = xsc;
        self = sc->sc_dev;

        pcm_init(self, sc);

        err = pcm_getbuffersize(self, AOA_BUFFER_SIZE, AOA_BUFFER_SIZE,
            AOA_BUFFER_SIZE);
        DPRINTF(("pcm_getbuffersize returned %d\n", err));

        pcm_addchan(self, PCMDIR_PLAY, &aoa_chan_class, sc);

        snprintf(status, sizeof(status), "at %s", ofw_bus_get_name(self)); 

        return (pcm_register(self, status));
}