/*
 *  This file is part of FH8620 BSP for RT-Thread distribution.
 *
 *  Copyright (c) 2016 Shanghai Fullhan Microelectronics Co., Ltd.
 *  All rights reserved
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 *  Visit http://www.fullhan.com to get contact with Fullhan.
 *
 * Change Logs:
 * Date           Author       Notes
 */

#include "timer.h"
#include <rtdevice.h>
#include "fh_arch.h"
#include "libraries/inc/fh_timer.h"
//#include "fh_pmu.h"
//#include "chip_reg.h"
//NEED_CAUTION.

#define TIMER_CLOCK 1000000

#define CONFIG_PAE_PTS_CLOCK   (1000000)
#define TICKS_PER_USEC         (CONFIG_PAE_PTS_CLOCK / 1000000)
#define REG_PAE_PTS_REG        (0xec100000 + 0x0040)

static unsigned long lastdec;
static unsigned long long timestamp;

rt_uint32_t read_pts(void)
{
    return GET_REG(REG_PAE_PTS_REG);
}

unsigned long long get_ticks(void)
{
    rt_uint32_t now = read_pts();
    if (now >= lastdec) {
        /* normal mode */
        timestamp += now - lastdec;
    } else {
        now = read_pts();
        if (now >= lastdec)
            timestamp += now - lastdec;
        else {
            /* we have an overflow ... */
            timestamp += now + 0xffffffff - lastdec;
        }
    }
    lastdec = now;
    return timestamp / (TICKS_PER_USEC * 10);
}

void udelay(unsigned long usec)
{
    unsigned long long tmp;
    rt_uint32_t tmo;
    tmo = (usec + 9) / 10;
    tmp = get_ticks() + tmo; /* get current timestamp */

    while (get_ticks() < tmp)
        /* loop till event */
        /*NOP*/;
}

void rt_timer_handler(int vector, void *param)
{
    timer *tim = param;

    rt_interrupt_enter();
    timer_get_eoi(tim);
    rt_tick_increase();
    rt_interrupt_leave();
}

/**
 * This function will init pit for system ticks
 */
void rt_hw_timer_init()
{
    timer *tim = (timer *) TMR_REG_BASE;
    timer_init(tim);
    /* install interrupt handler */
    rt_hw_interrupt_install(TMR0_IRQn, rt_timer_handler, (void *) tim,
                "sys_tick");
    rt_hw_interrupt_umask(TMR0_IRQn);

    timer_set_mode(tim, TIMER_MODE_PERIODIC);
    timer_set_period(tim, RT_TICK_PER_SECOND, TIMER_CLOCK);
    //timer_set_period(tim, RT_TIMER_TICK_PER_SECOND, TIMER_CLOCK);
    timer_enable_irq(tim);
    timer_enable(tim);

}