Archipelago » qemu

/*

 * Syborg RTC

 *

 * Copyright (c) 2008 CodeSourcery

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "sysbus.h"

#include "qemu-timer.h"

#include "syborg.h"

enum {

    RTC_ID        = 0,

    RTC_LATCH     = 1,

    RTC_DATA_LOW  = 2,

    RTC_DATA_HIGH = 3

};

typedef struct {

    SysBusDevice busdev;

    int64_t offset;

    int64_t data;

    qemu_irq irq;

} SyborgRTCState;

static uint32_t syborg_rtc_read(void *opaque, target_phys_addr_t offset)

{

    SyborgRTCState *s = (SyborgRTCState *)opaque;

    offset &= 0xfff;

    switch (offset >> 2) {

    case RTC_ID:

        return SYBORG_ID_RTC;

    case RTC_DATA_LOW:

        return (uint32_t)s->data;

    case RTC_DATA_HIGH:

        return (uint32_t)(s->data >> 32);

    default:

        cpu_abort(cpu_single_env, "syborg_rtc_read: Bad offset %x\n",

                  (int)offset);

        return 0;

    }

}

static void syborg_rtc_write(void *opaque, target_phys_addr_t offset, uint32_t value)

{

    SyborgRTCState *s = (SyborgRTCState *)opaque;

    uint64_t now;

    offset &= 0xfff;

    switch (offset >> 2) {

    case RTC_LATCH:

        now = qemu_get_clock(vm_clock);

        if (value >= 4) {

            s->offset = s->data - now;

        } else {

            s->data = now + s->offset;

            while (value) {

                s->data /= 1000;

                value--;

            }

        }

        break;

    case RTC_DATA_LOW:

        s->data = (s->data & ~(uint64_t)0xffffffffu) | value;

        break;

    case RTC_DATA_HIGH:

        s->data = (s->data & 0xffffffffu) | ((uint64_t)value << 32);

        break;

    default:

        cpu_abort(cpu_single_env, "syborg_rtc_write: Bad offset %x\n",

                  (int)offset);

        break;

    }

}

static CPUReadMemoryFunc * const syborg_rtc_readfn[] = {

    syborg_rtc_read,

    syborg_rtc_read,

    syborg_rtc_read

};

static CPUWriteMemoryFunc * const syborg_rtc_writefn[] = {

    syborg_rtc_write,

    syborg_rtc_write,

    syborg_rtc_write

};

static void syborg_rtc_save(QEMUFile *f, void *opaque)

{

    SyborgRTCState *s = opaque;

    qemu_put_be64(f, s->offset);

    qemu_put_be64(f, s->data);

}

static int syborg_rtc_load(QEMUFile *f, void *opaque, int version_id)

{

    SyborgRTCState *s = opaque;

    if (version_id != 1)

        return -EINVAL;

    s->offset = qemu_get_be64(f);

    s->data = qemu_get_be64(f);

    return 0;

}

static int syborg_rtc_init(SysBusDevice *dev)

{

    SyborgRTCState *s = FROM_SYSBUS(SyborgRTCState, dev);

    struct tm tm;

    int iomemtype;

    iomemtype = cpu_register_io_memory(syborg_rtc_readfn,

                                       syborg_rtc_writefn, s);

    sysbus_init_mmio(dev, 0x1000, iomemtype);

    qemu_get_timedate(&tm, 0);

    s->offset = (uint64_t)mktime(&tm) * 1000000000;

    register_savevm("syborg_rtc", -1, 1, syborg_rtc_save, syborg_rtc_load, s);

    return 0;

}

static void syborg_rtc_register_devices(void)

{

    sysbus_register_dev("syborg,rtc", sizeof(SyborgRTCState), syborg_rtc_init);

}

device_init(syborg_rtc_register_devices)