/*-
 * Copyright (c) 2011 Jung-uk Kim <jkim@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/fcntl.h>
#include <sys/mman.h>
#include <dev/acpica/acpi_hpet.h>

static __inline uint32_t
read32(caddr_t addr, u_int reg)
{

	return (*(volatile uint32_t *)(addr + reg));
}

static __inline uint64_t
read64(caddr_t addr, u_int reg)
{
#ifdef __i386__
	uint32_t high, low;

	do {
		high = read32(addr, reg + 4);
		low = read32(addr, reg);
	} while (high != read32(addr, reg + 4));
	return (((uint64_t)high << 32) | low);
#else
	return (*(volatile uint64_t *)(addr + reg));
#endif
}

int
main(void)
{
	uint64_t hpet64[10];
	uint32_t hpet32[10];
	caddr_t addr;
	uint32_t cap, cfg, prd;
	int fd, i;

	fd = open("/dev/hpet", O_RDONLY);
	if (fd < 0) {
		perror("open()");
		exit (1);
	}
	addr = mmap(NULL, HPET_MEM_WIDTH, PROT_READ, MAP_SHARED, fd, 0);
	if (addr == MAP_FAILED) {
		perror("mmap()");
		exit (1);
	}

	cap = read32(addr, HPET_CAPABILITIES);
	printf("HPET capabilities:\t0x%08x\n", cap);
	printf("\tVendor ID:\t0x%04x\n", (cap & HPET_CAP_VENDOR_ID) >> 16);
	printf("\tLegacy Route:\t%s\n",
	    (cap & HPET_CAP_LEG_RT) != 0 ? "yes" : "no");
	printf("\tCounter Width:\t%s-bit\n",
	    (cap & HPET_CAP_COUNT_SIZE) != 0 ? "64" : "32");
	printf("\tNo. of Timers:\t%u\n", ((cap & HPET_CAP_NUM_TIM) >> 8) + 1);
	printf("\tRevision ID:\t%u\n", cap & HPET_CAP_REV_ID);
	printf("\n");

	prd = read32(addr, HPET_PERIOD);
	printf("HPET period:\t\t0x%08x\n", prd);
	printf("\tFrequency:\t%llu Hz\n",
	    (1000000000000000ULL + prd / 2) / prd);
	printf("\n");

	cfg = read32(addr, HPET_CONFIG);
	printf("HPET configuration:\t0x%08x\n", cfg);
	printf("\tLegacy Route:\t%s\n",
	    (cfg & HPET_CNF_LEG_RT) != 0 ? "yes" : "no");
	printf("\tHPET Enabled:\t%s\n",
	    (cfg & HPET_CNF_ENABLE) != 0 ? "yes" : "no");
	printf("\n");

	printf("HPET main counter (32 bits):\n");
	for (i = 0; i < 10; i++)
		hpet32[i] = read32(addr, HPET_MAIN_COUNTER);
	printf("\t0x%08x\n", hpet32[0]);
	for (i = 1; i < 10; i++)
		printf("\t0x%08x (offset %d)\n", hpet32[i],
		    i > 0 ? hpet32[i] - hpet32[i - 1] : 0);
	printf("\n");

	printf("HPET main counter (64 bits):\n");
	for (i = 0; i < 10; i++)
		hpet64[i] = read64(addr, HPET_MAIN_COUNTER);
	printf("\t0x%016jx\n", (uintmax_t)hpet64[0]);
	for (i = 1; i < 10; i++)
		printf("\t0x%016jx (offset %jd)\n", (uintmax_t)hpet64[i],
		    i > 0 ? (uintmax_t)(hpet64[i] - hpet64[i - 1]) : 0);

	munmap(addr, HPET_MEM_WIDTH);
	close(fd);
	return (0);
}