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 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
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 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name of Maxim Integrated
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 * Products, Inc. Branding Policy.
 *
 * The mere transfer of this software does not imply any licenses
 * of trade secrets, proprietary technology, copyrights, patents,
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#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "max32670.h"
#include "gcr_regs.h"
#include "pwrseq_regs.h"
#include "mxc_sys.h"

uint32_t SystemCoreClock = HIRC_FREQ;

__weak void SystemCoreClockUpdate(void)
{
    uint32_t base_freq, div, clk_src;

    // Get the clock source and frequency
    clk_src = (MXC_GCR->clkctrl & MXC_F_GCR_CLKCTRL_SYSCLK_SEL);
    switch (clk_src) {
    case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_EXTCLK:
        base_freq = EXTCLK_FREQ;
        break;
    case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_ERFO:
        base_freq = ERFO_FREQ;
        break;
    case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_INRO:
        base_freq = INRO_FREQ;
        break;
    case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_IPO:
        base_freq = IPO_FREQ;
        break;
    case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_IBRO:
        base_freq = IBRO_FREQ;
        break;
    case MXC_S_GCR_CLKCTRL_SYSCLK_SEL_ERTCO:
        base_freq = ERTCO_FREQ;
        break;
    default:
        // Codes 001 and 111 are reserved.
        // This code should never execute, however, initialize to safe value.
        base_freq = HIRC_FREQ;
        break;
    }
    // Get the clock divider
    if (clk_src == MXC_S_GCR_CLKCTRL_SYSCLK_SEL_IPO) {
        base_freq = base_freq >> ((MXC_GCR->clkctrl & MXC_F_GCR_CLKCTRL_IPO_DIV) >>
                                  MXC_F_GCR_CLKCTRL_IPO_DIV_POS);
    }
    div = (MXC_GCR->clkctrl & MXC_F_GCR_CLKCTRL_SYSCLK_DIV) >> MXC_F_GCR_CLKCTRL_SYSCLK_DIV_POS;

    SystemCoreClock = base_freq >> div;
}

/* This function is called before C runtime initialization and can be
 * implemented by the application for early initializations. If a value other
 * than '0' is returned, the C runtime initialization will be skipped.
 *
 * You may over-ride this function in your program by defining a custom 
 *  PreInit(), but care should be taken to reproduce the initialization steps
 *  or a non-functional system may result.
 */
__weak int PreInit(void)
{
    /* Do nothing */
    return 0;
}

/* This function can be implemented by the application to initialize the board */
__weak int Board_Init(void)
{
    /* Do nothing */
    return 0;
}

/* Override this function for early platform initialization */
__weak void low_level_init(void) 
{
    /* Do nothing */
}

/* This function is called just before control is transferred to main().
 *
 * You may over-ride this function in your program by defining a custom 
 *  SystemInit(), but care should be taken to reproduce the initialization
 *  steps or a non-functional system may result.
 */
__weak void SystemInit(void)
{
    /* Make sure interrupts are enabled. */
    __enable_irq();

#if (__FPU_PRESENT == 1)
    /* Enable FPU on Cortex-M4, which occupies coprocessor slots 10 & 11 */
    /* Grant full access, per "Table B3-24 CPACR bit assignments". */
    /* DDI0403D "ARMv7-M Architecture Reference Manual" */
    SCB->CPACR |= SCB_CPACR_CP10_Msk | SCB_CPACR_CP11_Msk;
    __DSB();
    __ISB();
#endif

    /* Change system clock source to the main high-speed clock */
    MXC_SYS_Clock_Select(MXC_SYS_CLOCK_IPO);
    SystemCoreClockUpdate();

    MXC_SYS_ClockEnable(MXC_SYS_PERIPH_CLOCK_GPIO0);
    MXC_SYS_ClockEnable(MXC_SYS_PERIPH_CLOCK_GPIO1);

    low_level_init();
}