/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2000 David Jones <dej@ox.org>
 * 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 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 AUTHOR 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.
 */

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

#include <dev/sound/pcm/sound.h>
#include <dev/sound/pcm/ac97.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <sys/sysctl.h>

#include <dev/sound/pci/via82c686.h>

#define VIA_PCI_ID 0x30581106
#define NSEGS           4       /* Number of segments in SGD table */

#define SEGS_PER_CHAN   (NSEGS/2)

#define TIMEOUT 50
#define VIA_DEFAULT_BUFSZ       0x1000

#undef DEB
#define DEB(x)

/* we rely on this struct being packed to 64 bits */
struct via_dma_op {
        u_int32_t ptr;
        u_int32_t flags;
#define VIA_DMAOP_EOL         0x80000000
#define VIA_DMAOP_FLAG        0x40000000
#define VIA_DMAOP_STOP        0x20000000
#define VIA_DMAOP_COUNT(x)    ((x)&0x00FFFFFF)
};

struct via_info;

struct via_chinfo {
        struct via_info *parent;
        struct pcm_channel *channel;
        struct snd_dbuf *buffer;
        struct via_dma_op *sgd_table;
        bus_addr_t sgd_addr;
        int dir, blksz;
        int base, count, mode, ctrl;
};

struct via_info {
        bus_space_tag_t st;
        bus_space_handle_t sh;
        bus_dma_tag_t parent_dmat;
        bus_dma_tag_t sgd_dmat;
        bus_dmamap_t sgd_dmamap;
        bus_addr_t sgd_addr;

        struct resource *reg, *irq;
        int regid, irqid;
        void *ih;
        struct ac97_info *codec;

        unsigned int bufsz;

        struct via_chinfo pch, rch;
        struct via_dma_op *sgd_table;
        u_int16_t codec_caps;
        struct mtx lock;
};

static u_int32_t via_fmt[] = {
        SND_FORMAT(AFMT_U8, 1, 0),
        SND_FORMAT(AFMT_U8, 2, 0),
        SND_FORMAT(AFMT_S16_LE, 1, 0),
        SND_FORMAT(AFMT_S16_LE, 2, 0),
        0
};
static struct pcmchan_caps via_vracaps = {4000, 48000, via_fmt, 0};
static struct pcmchan_caps via_caps = {48000, 48000, via_fmt, 0};

static __inline u_int32_t
via_rd(struct via_info *via, int regno, int size)
{

        switch (size) {
        case 1:
                return bus_space_read_1(via->st, via->sh, regno);
        case 2:
                return bus_space_read_2(via->st, via->sh, regno);
        case 4:
                return bus_space_read_4(via->st, via->sh, regno);
        default:
                return 0xFFFFFFFF;
        }
}

static __inline void
via_wr(struct via_info *via, int regno, u_int32_t data, int size)
{

        switch (size) {
        case 1:
                bus_space_write_1(via->st, via->sh, regno, data);
                break;
        case 2:
                bus_space_write_2(via->st, via->sh, regno, data);
                break;
        case 4:
                bus_space_write_4(via->st, via->sh, regno, data);
                break;
        }
}

/* -------------------------------------------------------------------- */
/* Codec interface */

static int
via_waitready_codec(struct via_info *via)
{
        int i;

        /* poll until codec not busy */
        for (i = 0; (i < TIMEOUT) &&
            (via_rd(via, VIA_CODEC_CTL, 4) & VIA_CODEC_BUSY); i++)
                DELAY(1);
        if (i >= TIMEOUT) {
                printf("via: codec busy\n");
                return 1;
        }

        return 0;
}

static int
via_waitvalid_codec(struct via_info *via)
{
        int i;

        /* poll until codec valid */
        for (i = 0; (i < TIMEOUT) &&
            !(via_rd(via, VIA_CODEC_CTL, 4) & VIA_CODEC_PRIVALID); i++)
                    DELAY(1);
        if (i >= TIMEOUT) {
                printf("via: codec invalid\n");
                return 1;
        }

        return 0;
}

static int
via_write_codec(kobj_t obj, void *addr, int reg, u_int32_t val)
{
        struct via_info *via = addr;

        if (via_waitready_codec(via)) return -1;

        via_wr(via, VIA_CODEC_CTL, VIA_CODEC_PRIVALID | VIA_CODEC_INDEX(reg) | val, 4);

        return 0;
}

static int
via_read_codec(kobj_t obj, void *addr, int reg)
{
        struct via_info *via = addr;

        if (via_waitready_codec(via))
                return -1;

        via_wr(via, VIA_CODEC_CTL, VIA_CODEC_PRIVALID | VIA_CODEC_READ | VIA_CODEC_INDEX(reg),4);

        if (via_waitready_codec(via))
                return -1;

        if (via_waitvalid_codec(via))
                return -1;

        return via_rd(via, VIA_CODEC_CTL, 2);
}

static kobj_method_t via_ac97_methods[] = {
        KOBJMETHOD(ac97_read,           via_read_codec),
        KOBJMETHOD(ac97_write,          via_write_codec),
        KOBJMETHOD_END
};
AC97_DECLARE(via_ac97);

/* -------------------------------------------------------------------- */

static int
via_buildsgdt(struct via_chinfo *ch)
{
        u_int32_t phys_addr, flag;
        int i, segs, seg_size;

        /*
         *  Build the scatter/gather DMA (SGD) table.
         *  There are four slots in the table: two for play, two for record.
         *  This creates two half-buffers, one of which is playing; the other
         *  is feeding.
         */
        seg_size = ch->blksz;
        segs = ch->buffer->bufsize / seg_size;
        phys_addr = ch->buffer->buf_addr;

        for (i = 0; i < segs; i++) {
                flag = (i == segs - 1)? VIA_DMAOP_EOL : VIA_DMAOP_FLAG;
                ch->sgd_table[i].ptr = phys_addr + (i * seg_size);
                ch->sgd_table[i].flags = flag | seg_size;
        }

        return 0;
}

/* channel interface */
static void *
viachan_init(kobj_t obj, void *devinfo, struct snd_dbuf *b, struct pcm_channel *c, int dir)
{
        struct via_info *via = devinfo;
        struct via_chinfo *ch;

        mtx_lock(&via->lock);
        if (dir == PCMDIR_PLAY) {
                ch = &via->pch;
                ch->base = VIA_PLAY_DMAOPS_BASE;
                ch->count = VIA_PLAY_DMAOPS_COUNT;
                ch->ctrl = VIA_PLAY_CONTROL;
                ch->mode = VIA_PLAY_MODE;
                ch->sgd_addr = via->sgd_addr;
                ch->sgd_table = &via->sgd_table[0];
        } else {
                ch = &via->rch;
                ch->base = VIA_RECORD_DMAOPS_BASE;
                ch->count = VIA_RECORD_DMAOPS_COUNT;
                ch->ctrl = VIA_RECORD_CONTROL;
                ch->mode = VIA_RECORD_MODE;
                ch->sgd_addr = via->sgd_addr + sizeof(struct via_dma_op) * SEGS_PER_CHAN;
                ch->sgd_table = &via->sgd_table[SEGS_PER_CHAN];
        }

        ch->parent = via;
        ch->channel = c;
        ch->buffer = b;
        ch->dir = dir;
        mtx_unlock(&via->lock);

        if (sndbuf_alloc(ch->buffer, via->parent_dmat, 0, via->bufsz) != 0)
                return NULL;

        return ch;
}

static int
viachan_setformat(kobj_t obj, void *data, u_int32_t format)
{
        struct via_chinfo *ch = data;
        struct via_info *via = ch->parent;
        int mode, mode_set;

        mode_set = 0;
        if (AFMT_CHANNEL(format) > 1)
                mode_set |= VIA_RPMODE_STEREO;
        if (format & AFMT_S16_LE)
                mode_set |= VIA_RPMODE_16BIT;

        DEB(printf("set format: dir = %d, format=%x\n", ch->dir, format));
        mtx_lock(&via->lock);
        mode = via_rd(via, ch->mode, 1);
        mode &= ~(VIA_RPMODE_16BIT | VIA_RPMODE_STEREO);
        mode |= mode_set;
        via_wr(via, ch->mode, mode, 1);
        mtx_unlock(&via->lock);

        return 0;
}

static u_int32_t
viachan_setspeed(kobj_t obj, void *data, u_int32_t speed)
{
        struct via_chinfo *ch = data;
        struct via_info *via = ch->parent;
        int reg;

        /*
         *  Basic AC'97 defines a 48 kHz sample rate only.  For other rates,
         *  upsampling is required.
         *
         *  The VT82C686A does not perform upsampling, and neither do we.
         *  If the codec supports variable-rate audio (i.e. does the upsampling
         *  itself), then negotiate the rate with the codec.  Otherwise,
         *  return 48 kHz cuz that's all you got.
         */
        if (via->codec_caps & AC97_EXTCAP_VRA) {
                reg = (ch->dir == PCMDIR_PLAY)? AC97_REGEXT_FDACRATE : AC97_REGEXT_LADCRATE;
                return ac97_setrate(via->codec, reg, speed);
        } else
                return 48000;
}

static u_int32_t
viachan_setblocksize(kobj_t obj, void *data, u_int32_t blocksize)
{
        struct via_chinfo *ch = data;

        ch->blksz = blocksize;
        sndbuf_resize(ch->buffer, SEGS_PER_CHAN, ch->blksz);

        return ch->blksz;
}

static int
viachan_trigger(kobj_t obj, void *data, int go)
{
        struct via_chinfo *ch = data;
        struct via_info *via = ch->parent;
        bus_addr_t sgd_addr = ch->sgd_addr;

        if (!PCMTRIG_COMMON(go))
                return 0;

        DEB(printf("ado located at va=%p pa=%x\n", ch->sgd_table, sgd_addr));

        mtx_lock(&via->lock);
        if (go == PCMTRIG_START) {
                via_buildsgdt(ch);
                via_wr(via, ch->base, sgd_addr, 4);
                via_wr(via, ch->ctrl, VIA_RPCTRL_START, 1);
        } else
                via_wr(via, ch->ctrl, VIA_RPCTRL_TERMINATE, 1);
        mtx_unlock(&via->lock);

        DEB(printf("viachan_trigger: go=%d\n", go));
        return 0;
}

static u_int32_t
viachan_getptr(kobj_t obj, void *data)
{
        struct via_chinfo *ch = data;
        struct via_info *via = ch->parent;
        bus_addr_t sgd_addr = ch->sgd_addr;
        u_int32_t ptr, base, base1, len, seg;

        mtx_lock(&via->lock);
        base1 = via_rd(via, ch->base, 4);
        len = via_rd(via, ch->count, 4);
        base = via_rd(via, ch->base, 4);
        if (base != base1)      /* Avoid race hazard */
                len = via_rd(via, ch->count, 4);
        mtx_unlock(&via->lock);

        DEB(printf("viachan_getptr: len / base = %x / %x\n", len, base));

        /* Base points to SGD segment to do, one past current */

        /* Determine how many segments have been done */
        seg = (base - sgd_addr) / sizeof(struct via_dma_op);
        if (seg == 0)
                seg = SEGS_PER_CHAN;

        /* Now work out offset: seg less count */
        ptr = (seg * ch->buffer->bufsize / SEGS_PER_CHAN) - len;
        if (ch->dir == PCMDIR_REC) {
                /* DMA appears to operate on memory 'lines' of 32 bytes */
                /* so don't return any part line - it isn't in RAM yet  */
                ptr = ptr & ~0x1f;
        }

        DEB(printf("return ptr=%u\n", ptr));
        return ptr;
}

static struct pcmchan_caps *
viachan_getcaps(kobj_t obj, void *data)
{
        struct via_chinfo *ch = data;
        struct via_info *via = ch->parent;

        return (via->codec_caps & AC97_EXTCAP_VRA)? &via_vracaps : &via_caps;
}

static kobj_method_t viachan_methods[] = {
        KOBJMETHOD(channel_init,                viachan_init),
        KOBJMETHOD(channel_setformat,           viachan_setformat),
        KOBJMETHOD(channel_setspeed,            viachan_setspeed),
        KOBJMETHOD(channel_setblocksize,        viachan_setblocksize),
        KOBJMETHOD(channel_trigger,             viachan_trigger),
        KOBJMETHOD(channel_getptr,              viachan_getptr),
        KOBJMETHOD(channel_getcaps,             viachan_getcaps),
        KOBJMETHOD_END
};
CHANNEL_DECLARE(viachan);

/* -------------------------------------------------------------------- */

static void
via_intr(void *p)
{
        struct via_info *via = p;

        /* DEB(printf("viachan_intr\n")); */
        /* Read channel */
        mtx_lock(&via->lock);
        if (via_rd(via, VIA_PLAY_STAT, 1) & VIA_RPSTAT_INTR) {
                via_wr(via, VIA_PLAY_STAT, VIA_RPSTAT_INTR, 1);
                mtx_unlock(&via->lock);
                chn_intr(via->pch.channel);
                mtx_lock(&via->lock);
        }

        /* Write channel */
        if (via_rd(via, VIA_RECORD_STAT, 1) & VIA_RPSTAT_INTR) {
                via_wr(via, VIA_RECORD_STAT, VIA_RPSTAT_INTR, 1);
                mtx_unlock(&via->lock);
                chn_intr(via->rch.channel);
                return;
        }
        mtx_unlock(&via->lock);
}

/*
 *  Probe and attach the card
 */
static int
via_probe(device_t dev)
{
        if (pci_get_devid(dev) == VIA_PCI_ID) {
                device_set_desc(dev, "VIA VT82C686A");
                return BUS_PROBE_DEFAULT;
        }
        return ENXIO;
}

static void
dma_cb(void *p, bus_dma_segment_t *bds, int a, int b)
{
        struct via_info *via = (struct via_info *)p;
        via->sgd_addr = bds->ds_addr;
}

static int
via_attach(device_t dev)
{
        struct via_info *via = NULL;
        char status[SND_STATUSLEN];
        u_int32_t data, cnt;

        via = malloc(sizeof(*via), M_DEVBUF, M_WAITOK | M_ZERO);
        mtx_init(&via->lock, device_get_nameunit(dev), "snd_via82c686 softc",
            MTX_DEF);

        pci_enable_busmaster(dev);

        /* Wake up and reset AC97 if necessary */
        data = pci_read_config(dev, VIA_AC97STATUS, 1);

        if ((data & VIA_AC97STATUS_RDY) == 0) {
                /* Cold reset per ac97r2.3 spec (page 95) */
                pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN, 1);                        /* Assert low */
                DELAY(100);                                                                     /* Wait T_rst_low */
                pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN | VIA_ACLINK_NRST, 1);      /* Assert high */
                DELAY(5);                                                                       /* Wait T_rst2clk */
                pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN, 1);                        /* Assert low */
        } else {
                /* Warm reset */
                pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN, 1);                        /* Force no sync */
                DELAY(100);
                pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN | VIA_ACLINK_SYNC, 1);      /* Sync */
                DELAY(5);                                                                       /* Wait T_sync_high */
                pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_EN, 1);                        /* Force no sync */
                DELAY(5);                                                                       /* Wait T_sync2clk */
        }

        /* Power everything up */
        pci_write_config(dev, VIA_ACLINKCTRL, VIA_ACLINK_DESIRED, 1);   

        /* Wait for codec to become ready (largest reported delay here 310ms) */
        for (cnt = 0; cnt < 2000; cnt++) {
                data = pci_read_config(dev, VIA_AC97STATUS, 1);
                if (data & VIA_AC97STATUS_RDY) 
                        break;
                DELAY(5000);
        }

        via->regid = PCIR_BAR(0);
        via->reg = bus_alloc_resource_any(dev, SYS_RES_IOPORT,
                &via->regid, RF_ACTIVE);
        if (!via->reg) {
                device_printf(dev, "cannot allocate bus resource.");
                goto bad;
        }
        via->st = rman_get_bustag(via->reg);
        via->sh = rman_get_bushandle(via->reg);

        via->bufsz = pcm_getbuffersize(dev, 4096, VIA_DEFAULT_BUFSZ, 65536);

        via->irqid = 0;
        via->irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &via->irqid,
                RF_ACTIVE | RF_SHAREABLE);
        if (!via->irq || snd_setup_intr(dev, via->irq, INTR_MPSAFE, via_intr, via, &via->ih)) {
                device_printf(dev, "unable to map interrupt\n");
                goto bad;
        }

        via_wr(via, VIA_PLAY_MODE, VIA_RPMODE_AUTOSTART | VIA_RPMODE_INTR_FLAG | VIA_RPMODE_INTR_EOL, 1);
        via_wr(via, VIA_RECORD_MODE, VIA_RPMODE_AUTOSTART | VIA_RPMODE_INTR_FLAG | VIA_RPMODE_INTR_EOL, 1);

        via->codec = AC97_CREATE(dev, via, via_ac97);
        if (!via->codec)
                goto bad;

        if (mixer_init(dev, ac97_getmixerclass(), via->codec))
                goto bad;

        via->codec_caps = ac97_getextcaps(via->codec);
        ac97_setextmode(via->codec, 
                        via->codec_caps & (AC97_EXTCAP_VRA | AC97_EXTCAP_VRM));

        /* DMA tag for buffers */
        if (bus_dma_tag_create(/*parent*/bus_get_dma_tag(dev), /*alignment*/2,
                /*boundary*/0,
                /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                /*highaddr*/BUS_SPACE_MAXADDR,
                /*filter*/NULL, /*filterarg*/NULL,
                /*maxsize*/via->bufsz, /*nsegments*/1, /*maxsegz*/0x3ffff,
                /*flags*/0, /*lockfunc*/NULL,
                /*lockarg*/NULL, &via->parent_dmat) != 0) {
                device_printf(dev, "unable to create dma tag\n");
                goto bad;
        }

        /*
         *  DMA tag for SGD table.  The 686 uses scatter/gather DMA and
         *  requires a list in memory of work to do.  We need only 16 bytes
         *  for this list, and it is wasteful to allocate 16K.
         */
        if (bus_dma_tag_create(/*parent*/bus_get_dma_tag(dev), /*alignment*/2,
                /*boundary*/0,
                /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                /*highaddr*/BUS_SPACE_MAXADDR,
                /*filter*/NULL, /*filterarg*/NULL,
                /*maxsize*/NSEGS * sizeof(struct via_dma_op),
                /*nsegments*/1, /*maxsegz*/0x3ffff,
                /*flags*/0, /*lockfunc*/NULL,
                /*lockarg*/NULL, &via->sgd_dmat) != 0) {
                device_printf(dev, "unable to create dma tag\n");
                goto bad;
        }

        if (bus_dmamem_alloc(via->sgd_dmat, (void **)&via->sgd_table,
            BUS_DMA_NOWAIT, &via->sgd_dmamap) != 0)
                goto bad;
        if (bus_dmamap_load(via->sgd_dmat, via->sgd_dmamap, via->sgd_table,
            NSEGS * sizeof(struct via_dma_op), dma_cb, via, 0) != 0)
                goto bad;

        snprintf(status, SND_STATUSLEN, "port 0x%jx irq %jd on %s",
                 rman_get_start(via->reg), rman_get_start(via->irq),
                 device_get_nameunit(device_get_parent(dev)));

        /* Register */
        pcm_init(dev, via);
        pcm_addchan(dev, PCMDIR_PLAY, &viachan_class, via);
        pcm_addchan(dev, PCMDIR_REC, &viachan_class, via);
        if (pcm_register(dev, status))
                goto bad;
        return 0;
bad:
        if (via->codec) ac97_destroy(via->codec);
        if (via->reg) bus_release_resource(dev, SYS_RES_IOPORT, via->regid, via->reg);
        if (via->ih) bus_teardown_intr(dev, via->irq, via->ih);
        if (via->irq) bus_release_resource(dev, SYS_RES_IRQ, via->irqid, via->irq);
        if (via->parent_dmat) bus_dma_tag_destroy(via->parent_dmat);
        if (via->sgd_addr) bus_dmamap_unload(via->sgd_dmat, via->sgd_dmamap);
        if (via->sgd_table) bus_dmamem_free(via->sgd_dmat, via->sgd_table, via->sgd_dmamap);
        if (via->sgd_dmat) bus_dma_tag_destroy(via->sgd_dmat);
        mtx_destroy(&via->lock);
        free(via, M_DEVBUF);
        return ENXIO;
}

static int
via_detach(device_t dev)
{
        int r;
        struct via_info *via = NULL;

        r = pcm_unregister(dev);
        if (r)
                return r;

        via = pcm_getdevinfo(dev);
        bus_release_resource(dev, SYS_RES_IOPORT, via->regid, via->reg);
        bus_teardown_intr(dev, via->irq, via->ih);
        bus_release_resource(dev, SYS_RES_IRQ, via->irqid, via->irq);
        bus_dma_tag_destroy(via->parent_dmat);
        bus_dmamap_unload(via->sgd_dmat, via->sgd_dmamap);
        bus_dmamem_free(via->sgd_dmat, via->sgd_table, via->sgd_dmamap);
        bus_dma_tag_destroy(via->sgd_dmat);
        mtx_destroy(&via->lock);
        free(via, M_DEVBUF);
        return 0;
}

static device_method_t via_methods[] = {
        DEVMETHOD(device_probe,         via_probe),
        DEVMETHOD(device_attach,        via_attach),
        DEVMETHOD(device_detach,        via_detach),
        { 0, 0}
};

static driver_t via_driver = {
        "pcm",
        via_methods,
        PCM_SOFTC_SIZE,
};

DRIVER_MODULE(snd_via82c686, pci, via_driver, 0, 0);
MODULE_DEPEND(snd_via82c686, sound, SOUND_MINVER, SOUND_PREFVER, SOUND_MAXVER);
MODULE_VERSION(snd_via82c686, 1);