/*
 * QEMU Geforce NV2A implementation
 *
 * Copyright (c) 2012 espes
 * Copyright (c) 2015 Jannik Vogel
 * Copyright (c) 2018-2021 Matt Borgerson
 *
 * 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/>.
 */

#include "nv2a_int.h"

/* PTIMER - time measurement and time-based alarms */
static uint64_t ptimer_get_clock(NV2AState *d)
{
    return muldiv64(muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
                             d->pramdac.core_clock_freq,
                             NANOSECONDS_PER_SECOND),
                    d->ptimer.denominator,
                    d->ptimer.numerator);
}

uint64_t ptimer_read(void *opaque, hwaddr addr, unsigned int size)
{
    NV2AState *d = opaque;

    uint64_t r = 0;
    switch (addr) {
    case NV_PTIMER_INTR_0:
        r = d->ptimer.pending_interrupts;
        break;
    case NV_PTIMER_INTR_EN_0:
        r = d->ptimer.enabled_interrupts;
        break;
    case NV_PTIMER_NUMERATOR:
        r = d->ptimer.numerator;
        break;
    case NV_PTIMER_DENOMINATOR:
        r = d->ptimer.denominator;
        break;
    case NV_PTIMER_TIME_0:
        r = (ptimer_get_clock(d) & 0x7ffffff) << 5;
        break;
    case NV_PTIMER_TIME_1:
        r = (ptimer_get_clock(d) >> 27) & 0x1fffffff;
        break;
    default:
        break;
    }

    nv2a_reg_log_read(NV_PTIMER, addr, size, r);
    return r;
}

void ptimer_write(void *opaque, hwaddr addr, uint64_t val, unsigned int size)
{
    NV2AState *d = opaque;

    nv2a_reg_log_write(NV_PTIMER, addr, size, val);

    switch (addr) {
    case NV_PTIMER_INTR_0:
        d->ptimer.pending_interrupts &= ~val;
        nv2a_update_irq(d);
        break;
    case NV_PTIMER_INTR_EN_0:
        d->ptimer.enabled_interrupts = val;
        nv2a_update_irq(d);
        break;
    case NV_PTIMER_DENOMINATOR:
        d->ptimer.denominator = val;
        break;
    case NV_PTIMER_NUMERATOR:
        d->ptimer.numerator = val;
        break;
    case NV_PTIMER_ALARM_0:
        d->ptimer.alarm_time = val;
        break;
    default:
        break;
    }
}