Archipelago » qemu

/*

 *  QEMU model of the Milkymist High Performance Dynamic Memory 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/hpdmc.pdf

 */

#include "hw/hw.h"

#include "hw/sysbus.h"

#include "trace.h"

#include "qemu/error-report.h"

enum {

    R_SYSTEM = 0,

    R_BYPASS,

    R_TIMING,

    R_IODELAY,

    R_MAX

};

enum {

    IODELAY_DQSDELAY_RDY = (1<<5),

    IODELAY_PLL1_LOCKED  = (1<<6),

    IODELAY_PLL2_LOCKED  = (1<<7),

};

struct MilkymistHpdmcState {

    SysBusDevice busdev;

    MemoryRegion regs_region;

    uint32_t regs[R_MAX];

};

typedef struct MilkymistHpdmcState MilkymistHpdmcState;

static uint64_t hpdmc_read(void *opaque, hwaddr addr,

                           unsigned size)

{

    MilkymistHpdmcState *s = opaque;

    uint32_t r = 0;

    addr >>= 2;

    switch (addr) {

    case R_SYSTEM:

    case R_BYPASS:

    case R_TIMING:

    case R_IODELAY:

        r = s->regs[addr];

        break;

    default:

        error_report("milkymist_hpdmc: read access to unknown register 0x"

                TARGET_FMT_plx, addr << 2);

        break;

    }

    trace_milkymist_hpdmc_memory_read(addr << 2, r);

    return r;

}

static void hpdmc_write(void *opaque, hwaddr addr, uint64_t value,

                        unsigned size)

{

    MilkymistHpdmcState *s = opaque;

    trace_milkymist_hpdmc_memory_write(addr, value);

    addr >>= 2;

    switch (addr) {

    case R_SYSTEM:

    case R_BYPASS:

    case R_TIMING:

        s->regs[addr] = value;

        break;

    case R_IODELAY:

        /* ignore writes */

        break;

    default:

        error_report("milkymist_hpdmc: write access to unknown register 0x"

                TARGET_FMT_plx, addr << 2);

        break;

    }

}

static const MemoryRegionOps hpdmc_mmio_ops = {

    .read = hpdmc_read,

    .write = hpdmc_write,

    .valid = {

        .min_access_size = 4,

        .max_access_size = 4,

    },

    .endianness = DEVICE_NATIVE_ENDIAN,

};

static void milkymist_hpdmc_reset(DeviceState *d)

{

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

    int i;

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

        s->regs[i] = 0;

    }

    /* defaults */

    s->regs[R_IODELAY] = IODELAY_DQSDELAY_RDY | IODELAY_PLL1_LOCKED

                         | IODELAY_PLL2_LOCKED;

}

static int milkymist_hpdmc_init(SysBusDevice *dev)

{

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

    memory_region_init_io(&s->regs_region, &hpdmc_mmio_ops, s,

            "milkymist-hpdmc", R_MAX * 4);

    sysbus_init_mmio(dev, &s->regs_region);

    return 0;

}

static const VMStateDescription vmstate_milkymist_hpdmc = {

    .name = "milkymist-hpdmc",

    .version_id = 1,

    .minimum_version_id = 1,

    .minimum_version_id_old = 1,

    .fields      = (VMStateField[]) {

        VMSTATE_UINT32_ARRAY(regs, MilkymistHpdmcState, R_MAX),

        VMSTATE_END_OF_LIST()

    }

};

static void milkymist_hpdmc_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

    k->init = milkymist_hpdmc_init;

    dc->reset = milkymist_hpdmc_reset;

    dc->vmsd = &vmstate_milkymist_hpdmc;

}

static const TypeInfo milkymist_hpdmc_info = {

    .name          = "milkymist-hpdmc",

    .parent        = TYPE_SYS_BUS_DEVICE,

    .instance_size = sizeof(MilkymistHpdmcState),

    .class_init    = milkymist_hpdmc_class_init,

};

static void milkymist_hpdmc_register_types(void)

{

    type_register_static(&milkymist_hpdmc_info);

}

type_init(milkymist_hpdmc_register_types)