Archipelago » qemu

/*

 *  QEMU model of the Milkymist System Controller.

 *

 *  Copyright (c) 2010 Michael Walle <michael@walle.cc>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 *

 *

 * Specification available at:

 *   http://www.milkymist.org/socdoc/ac97.pdf

 */

#include "hw.h"

#include "sysbus.h"

#include "trace.h"

#include "audio/audio.h"

#include "qemu-error.h"

enum {

    R_AC97_CTRL = 0,

    R_AC97_ADDR,

    R_AC97_DATAOUT,

    R_AC97_DATAIN,

    R_D_CTRL,

    R_D_ADDR,

    R_D_REMAINING,

    R_RESERVED,

    R_U_CTRL,

    R_U_ADDR,

    R_U_REMAINING,

    R_MAX

};

enum {

    AC97_CTRL_RQEN  = (1<<0),

    AC97_CTRL_WRITE = (1<<1),

};

enum {

    CTRL_EN = (1<<0),

};

struct MilkymistAC97State {

    SysBusDevice busdev;

    QEMUSoundCard card;

    SWVoiceIn *voice_in;

    SWVoiceOut *voice_out;

    uint32_t regs[R_MAX];

    qemu_irq crrequest_irq;

    qemu_irq crreply_irq;

    qemu_irq dmar_irq;

    qemu_irq dmaw_irq;

};

typedef struct MilkymistAC97State MilkymistAC97State;

static void update_voices(MilkymistAC97State *s)

{

    if (s->regs[R_D_CTRL] & CTRL_EN) {

        AUD_set_active_out(s->voice_out, 1);

    } else {

        AUD_set_active_out(s->voice_out, 0);

    }

    if (s->regs[R_U_CTRL] & CTRL_EN) {

        AUD_set_active_in(s->voice_in, 1);

    } else {

        AUD_set_active_in(s->voice_in, 0);

    }

}

static uint32_t ac97_read(void *opaque, target_phys_addr_t addr)

{

    MilkymistAC97State *s = opaque;

    uint32_t r = 0;

    addr >>= 2;

    switch (addr) {

    case R_AC97_CTRL:

    case R_AC97_ADDR:

    case R_AC97_DATAOUT:

    case R_AC97_DATAIN:

    case R_D_CTRL:

    case R_D_ADDR:

    case R_D_REMAINING:

    case R_U_CTRL:

    case R_U_ADDR:

    case R_U_REMAINING:

        r = s->regs[addr];

        break;

    default:

        error_report("milkymist_ac97: read access to unkown register 0x"

                TARGET_FMT_plx, addr << 2);

        break;

    }

    trace_milkymist_ac97_memory_read(addr << 2, r);

    return r;

}

static void ac97_write(void *opaque, target_phys_addr_t addr, uint32_t value)

{

    MilkymistAC97State *s = opaque;

    trace_milkymist_ac97_memory_write(addr, value);

    addr >>= 2;

    switch (addr) {

    case R_AC97_CTRL:

        /* always raise an IRQ according to the direction */

        if (value & AC97_CTRL_RQEN) {

            if (value & AC97_CTRL_WRITE) {

                trace_milkymist_ac97_pulse_irq_crrequest();

                qemu_irq_pulse(s->crrequest_irq);

            } else {

                trace_milkymist_ac97_pulse_irq_crreply();

                qemu_irq_pulse(s->crreply_irq);

            }

        }

        /* RQEN is self clearing */

        s->regs[addr] = value & ~AC97_CTRL_RQEN;

        break;

    case R_D_CTRL:

    case R_U_CTRL:

        s->regs[addr] = value;

        update_voices(s);

        break;

    case R_AC97_ADDR:

    case R_AC97_DATAOUT:

    case R_AC97_DATAIN:

    case R_D_ADDR:

    case R_D_REMAINING:

    case R_U_ADDR:

    case R_U_REMAINING:

        s->regs[addr] = value;

        break;

    default:

        error_report("milkymist_ac97: write access to unkown register 0x"

                TARGET_FMT_plx, addr);

        break;

    }

}

static CPUReadMemoryFunc * const ac97_read_fn[] = {

    NULL,

    NULL,

    &ac97_read,

};

static CPUWriteMemoryFunc * const ac97_write_fn[] = {

    NULL,

    NULL,

    &ac97_write,

};

static void ac97_in_cb(void *opaque, int avail_b)

{

    MilkymistAC97State *s = opaque;

    uint8_t buf[4096];

    uint32_t remaining = s->regs[R_U_REMAINING];

    int temp = audio_MIN(remaining, avail_b);

    uint32_t addr = s->regs[R_U_ADDR];

    int transferred = 0;

    trace_milkymist_ac97_in_cb(avail_b, remaining);

    /* prevent from raising an IRQ */

    if (temp == 0) {

        return;

    }

    while (temp) {

        int acquired, to_copy;

        to_copy = audio_MIN(temp, sizeof(buf));

        acquired = AUD_read(s->voice_in, buf, to_copy);

        if (!acquired) {

            break;

        }

        cpu_physical_memory_write(addr, buf, acquired);

        temp -= acquired;

        addr += acquired;

        transferred += acquired;

    }

    trace_milkymist_ac97_in_cb_transferred(transferred);

    s->regs[R_U_ADDR] = addr;

    s->regs[R_U_REMAINING] -= transferred;

    if ((s->regs[R_U_CTRL] & CTRL_EN) && (s->regs[R_U_REMAINING] == 0)) {

        trace_milkymist_ac97_pulse_irq_dmaw();

        qemu_irq_pulse(s->dmaw_irq);

    }

}

static void ac97_out_cb(void *opaque, int free_b)

{

    MilkymistAC97State *s = opaque;

    uint8_t buf[4096];

    uint32_t remaining = s->regs[R_D_REMAINING];

    int temp = audio_MIN(remaining, free_b);

    uint32_t addr = s->regs[R_D_ADDR];

    int transferred = 0;

    trace_milkymist_ac97_out_cb(free_b, remaining);

    /* prevent from raising an IRQ */

    if (temp == 0) {

        return;

    }

    while (temp) {

        int copied, to_copy;

        to_copy = audio_MIN(temp, sizeof(buf));

        cpu_physical_memory_read(addr, buf, to_copy);

        copied = AUD_write(s->voice_out, buf, to_copy);

        if (!copied) {

            break;

        }

        temp -= copied;

        addr += copied;

        transferred += copied;

    }

    trace_milkymist_ac97_out_cb_transferred(transferred);

    s->regs[R_D_ADDR] = addr;

    s->regs[R_D_REMAINING] -= transferred;

    if ((s->regs[R_D_CTRL] & CTRL_EN) && (s->regs[R_D_REMAINING] == 0)) {

        trace_milkymist_ac97_pulse_irq_dmar();

        qemu_irq_pulse(s->dmar_irq);

    }

}

static void milkymist_ac97_reset(DeviceState *d)

{

    MilkymistAC97State *s = container_of(d, MilkymistAC97State, busdev.qdev);

    int i;

    for (i = 0; i < R_MAX; i++) {

        s->regs[i] = 0;

    }

    AUD_set_active_in(s->voice_in, 0);

    AUD_set_active_out(s->voice_out, 0);

}

static int ac97_post_load(void *opaque, int version_id)

{

    MilkymistAC97State *s = opaque;

    update_voices(s);

    return 0;

}

static int milkymist_ac97_init(SysBusDevice *dev)

{

    MilkymistAC97State *s = FROM_SYSBUS(typeof(*s), dev);

    int ac97_regs;

    struct audsettings as;

    sysbus_init_irq(dev, &s->crrequest_irq);

    sysbus_init_irq(dev, &s->crreply_irq);

    sysbus_init_irq(dev, &s->dmar_irq);

    sysbus_init_irq(dev, &s->dmaw_irq);

    AUD_register_card("Milkymist AC'97", &s->card);

    as.freq = 48000;

    as.nchannels = 2;

    as.fmt = AUD_FMT_S16;

    as.endianness = 1;

    s->voice_in = AUD_open_in(&s->card, s->voice_in,

            "mm_ac97.in", s, ac97_in_cb, &as);

    s->voice_out = AUD_open_out(&s->card, s->voice_out,

            "mm_ac97.out", s, ac97_out_cb, &as);

    ac97_regs = cpu_register_io_memory(ac97_read_fn, ac97_write_fn, s,

            DEVICE_NATIVE_ENDIAN);

    sysbus_init_mmio(dev, R_MAX * 4, ac97_regs);

    return 0;

}

static const VMStateDescription vmstate_milkymist_ac97 = {

    .name = "milkymist-ac97",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .post_load = ac97_post_load,

    .fields      = (VMStateField[]) {

        VMSTATE_UINT32_ARRAY(regs, MilkymistAC97State, R_MAX),

        VMSTATE_END_OF_LIST()

    }

};

static SysBusDeviceInfo milkymist_ac97_info = {

    .init = milkymist_ac97_init,

    .qdev.name  = "milkymist-ac97",

    .qdev.size  = sizeof(MilkymistAC97State),

    .qdev.vmsd  = &vmstate_milkymist_ac97,

    .qdev.reset = milkymist_ac97_reset,

};

static void milkymist_ac97_register(void)

{

    sysbus_register_withprop(&milkymist_ac97_info);

}

device_init(milkymist_ac97_register)