/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2022 Oxide Computer Company
 */

#include "payload_common.h"
#include "payload_utils.h"
#include "test_defs.h"

#define HPET_OFF_CONFIG                 0x10
#define HPET_OFF_MAIN_COUNT_LOW         0xf0

#define HPET_CONFIG_ENABLE      1


static void
write_hpet(uint_t reg, uint32_t value)
{
        volatile uint32_t *ptr = (uint32_t *)(MMIO_HPET_BASE + reg);
        *ptr = value;
}

static uint32_t
read_hpet_main_low(void)
{
        volatile uint32_t *ptr =
            (uint32_t *)(MMIO_HPET_BASE + HPET_OFF_MAIN_COUNT_LOW);
        return (*ptr);
}


void
start(void)
{
        write_hpet(HPET_OFF_CONFIG, HPET_CONFIG_ENABLE);

        /* loop for as long as the host wants */
        for (;;) {
                uint32_t start, end;

                start = read_hpet_main_low();
                outl(IOP_TEST_VALUE, start);

                do {
                        end = read_hpet_main_low();
                        /* wait for enough ticks to pass */
                } while (end < (start + HPET_TARGET_TICKS));
                outl(IOP_TEST_VALUE, end);
        }
}