/*
 * Copyright (c) 2014, Freescale Semiconductor, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * o Redistributions of source code must retain the above copyright notice, this list
 *   of conditions and the following disclaimer.
 *
 * o 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.
 *
 * o Neither the name of Freescale Semiconductor, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived from this
 *   software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 "systick/systick.h"

////////////////////////////////////////////////////////////////////////////////
// Variables
////////////////////////////////////////////////////////////////////////////////
static systick_hook_t systick_hook;

////////////////////////////////////////////////////////////////////////////////
// Code
////////////////////////////////////////////////////////////////////////////////

//! @brief Initialize SysTick Module
status_t systick_init(uint32_t ticks)
{
    if (ticks > SysTick_LOAD_RELOAD_Msk)
    {
        return kStatus_InvalidArgument;
    }

    SysTick->LOAD = (ticks & SysTick_LOAD_RELOAD_Msk) - 1; /* set reload register */
    SysTick->VAL = 0;                                      /* Load the SysTick Counter Value */
    SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_TICKINT_Msk |
                    SysTick_CTRL_ENABLE_Msk; /* Enable SysTick IRQ and SysTick Timer */

    return kStatus_Success;
}

//! @brief Set Systick IRQ hook.
void systick_set_hook(systick_hook_t hook)
{
    systick_hook = hook;
}

//! @brief Shutdown Systick timer and interrupts
void systick_shutdown(void)
{
    // Disable the timer and interrupts from it
    SysTick->CTRL = SysTick->CTRL & ~(SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_TICKINT_Msk);
}

//! @brief SysTick interrupt handler
void SysTick_Handler(void)
{
    if (systick_hook)
    {
        systick_hook();
    }
}
