/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright 2019 Sony Semiconductor Solutions Corporation
 *
 * 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 <stdbool.h>
#include <sys/time.h>
#include <cxd56_clock.h>
#include <sys/boardctl.h>

#include "py/mpstate.h"

#include "supervisor/shared/tick.h"

#define DELAY_CORRECTION    (700)
#define DELAY_INTERVAL      (50)

void mp_hal_init(void) {
    boardctl(BOARDIOC_INIT, 0);
}

mp_uint_t mp_hal_ticks_ms(void) {
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return tv.tv_sec * 1000 + tv.tv_usec / 1000;
}

mp_uint_t mp_hal_ticks_us(void) {
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return tv.tv_sec * 1000000 + tv.tv_usec;
}

mp_uint_t mp_hal_ticks_cpu(void) {
    return cxd56_get_cpu_baseclk();
}

void mp_hal_delay_ms(mp_uint_t delay) {
    uint64_t start_tick = supervisor_ticks_ms64();
    uint64_t duration = 0;
    while (duration < delay) {
        #ifdef MICROPY_VM_HOOK_LOOP
            MICROPY_VM_HOOK_LOOP
        #endif
        // Check to see if we've been CTRL-Ced by autoreload or the user.
        if(MP_STATE_VM(mp_pending_exception) == MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_kbd_exception)) ||
           MP_STATE_VM(mp_pending_exception) == MP_OBJ_FROM_PTR(&MP_STATE_VM(mp_reload_exception))) {
            break;
        }
        duration = (supervisor_ticks_ms64() - start_tick);
        // TODO(tannewt): Go to sleep for a little while while we wait.
    }
}

void mp_hal_delay_us(uint32_t us) {
    if (us) {
        unsigned long long ticks = mp_hal_ticks_cpu() / 1000000L * us;
        if (ticks < DELAY_CORRECTION) return; // delay time already used in calculation

        ticks -= DELAY_CORRECTION;
        ticks /= 6;
        // following loop takes 6 cycles
        do {
            __asm__ __volatile__("nop");
        } while(--ticks);
    }
}