/**************************************************************************//**
 * @file     main.c
 * @version  V0.10
 * @brief    Read/write EEPROM via I2C interface
 *
 * SPDX-License-Identifier: Apache-2.0
 * @copyright (C) 2020 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NuMicro.h"

/*---------------------------------------------------------------------------------------------------------*/
/* Global variables                                                                                        */
/*---------------------------------------------------------------------------------------------------------*/
uint8_t g_u8DeviceAddr;
uint8_t g_au8TxData[3];
volatile uint8_t g_u8RxData;
volatile uint8_t g_u8DataLen;
volatile uint8_t g_u8EndFlag = 0;

typedef void (*I2C_FUNC)(uint32_t u32Status);

static I2C_FUNC s_pfnI2C0Handler = NULL;

/*---------------------------------------------------------------------------------------------------------*/
/*  I2C0 IRQ Handler                                                                                       */
/*---------------------------------------------------------------------------------------------------------*/
void I2C0_IRQHandler(void)
{
    uint32_t u32Status;

    u32Status = I2C_GET_STATUS(I2C0);

    if (I2C_GET_TIMEOUT_FLAG(I2C0))
    {
        /* Clear I2C0 Timeout Flag */
        I2C_ClearTimeoutFlag(I2C0);
    }
    else
    {
        if (s_pfnI2C0Handler != NULL)
            s_pfnI2C0Handler(u32Status);
    }
}

/*---------------------------------------------------------------------------------------------------------*/
/*  I2C Rx Callback Function                                                                               */
/*---------------------------------------------------------------------------------------------------------*/
void I2C_MasterRx(uint32_t u32Status)
{
    if (u32Status == 0x08)                      /* START has been transmitted and prepare SLA+W */
    {
        I2C_SET_DATA(I2C0, (g_u8DeviceAddr << 1)); /* Write SLA+W to Register I2CDAT */
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }
    else if (u32Status == 0x18)                 /* SLA+W has been transmitted and ACK has been received */
    {
        I2C_SET_DATA(I2C0, g_au8TxData[g_u8DataLen++]);
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }
    else if (u32Status == 0x20)                 /* SLA+W has been transmitted and NACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STO | I2C_CTL_SI);
    }
    else if (u32Status == 0x28)                 /* DATA has been transmitted and ACK has been received */
    {
        if (g_u8DataLen < 2)
        {
            I2C_SET_DATA(I2C0, g_au8TxData[g_u8DataLen++]);
            I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
        }
        else
        {
            I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STA | I2C_CTL_SI);
        }
    }
    else if (u32Status == 0x10)                 /* Repeat START has been transmitted and prepare SLA+R */
    {
        I2C_SET_DATA(I2C0, (g_u8DeviceAddr << 1) | 0x01);  /* Write SLA+R to Register I2CDAT */
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }
    else if (u32Status == 0x40)                 /* SLA+R has been transmitted and ACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }
    else if (u32Status == 0x58)                 /* DATA has been received and NACK has been returned */
    {
        g_u8RxData = I2C_GET_DATA(I2C0);
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STO | I2C_CTL_SI);
        g_u8EndFlag = 1;
    }
    else
    {
        /* TO DO */
        printf("Status 0x%x is NOT processed\n", u32Status);
    }
}

/*---------------------------------------------------------------------------------------------------------*/
/*  I2C Tx Callback Function                                                                               */
/*---------------------------------------------------------------------------------------------------------*/
void I2C_MasterTx(uint32_t u32Status)
{
    if (u32Status == 0x08)                      /* START has been transmitted */
    {
        I2C_SET_DATA(I2C0, g_u8DeviceAddr << 1);  /* Write SLA+W to Register I2CDAT */
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }
    else if (u32Status == 0x18)                 /* SLA+W has been transmitted and ACK has been received */
    {
        I2C_SET_DATA(I2C0, g_au8TxData[g_u8DataLen++]);
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }
    else if (u32Status == 0x20)                 /* SLA+W has been transmitted and NACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STA | I2C_CTL_STO | I2C_CTL_SI);
    }
    else if (u32Status == 0x28)                 /* DATA has been transmitted and ACK has been received */
    {
        if (g_u8DataLen != 3)
        {
            I2C_SET_DATA(I2C0, g_au8TxData[g_u8DataLen++]);
            I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
        }
        else
        {
            I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STO | I2C_CTL_SI);
            g_u8EndFlag = 1;
        }
    }
    else
    {
        /* TO DO */
        printf("Status 0x%x is NOT processed\n", u32Status);
    }
}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable Internal RC 48 MHz clock */
    CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);

    /* Waiting for Internal RC clock ready */
    CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);

    /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
    CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));

    /* Debug UART clock setting */
    UartDebugCLK();

    /* Enable I2C0 clock */
    CLK_EnableModuleClock(I2C0_MODULE);

    /* Enable GPIO clock */
    CLK_EnableModuleClock(GPB_MODULE);

    /* Update System Core Clock */
    /* User can use SystemCoreClockUpdate() to calculate SystemCoreClock and cyclesPerUs automatically. */
    SystemCoreClockUpdate();

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    UartDebugMFP();

    /* Set I2C0 multi-function pins */
    SYS->GPB_MFPL = (SYS->GPB_MFPL & ~(SYS_GPB_MFPL_PB4MFP_Msk | SYS_GPB_MFPL_PB5MFP_Msk)) |
                    (SYS_GPB_MFPL_PB4MFP_I2C0_SDA | SYS_GPB_MFPL_PB5MFP_I2C0_SCL);

    /* I2C pins enable schmitt trigger */
    PB->SMTEN |= GPIO_SMTEN_SMTEN4_Msk | GPIO_SMTEN_SMTEN5_Msk;
}

void I2C0_Init(void)
{
    /* Open I2C0 and set clock to 100k */
    I2C_Open(I2C0, 100000);

    /* Get I2C0 Bus Clock */
    printf("I2C clock %d Hz\n", I2C_GetBusClockFreq(I2C0));

    I2C_EnableInt(I2C0);
    NVIC_EnableIRQ(I2C0_IRQn);
}

/*---------------------------------------------------------------------------------------------------------*/
/*  Main Function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
    uint32_t i;

    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Init System, IP clock and multi-function I/O */
    SYS_Init();

    /* Init UART for message printing */
    UartDebugInit();

    /*
        This sample code sets I2C bus clock to 100kHz. Then, accesses EEPROM 24LC64 with Byte Write
        and Byte Read operations, and check if the read data is equal to the programmed data.
    */

    printf("+-------------------------------------------------------+\n");
    printf("|          I2C Driver Sample Code with EEPROM 24LC64    |\n");
    printf("+-------------------------------------------------------+\n");

    /* Init I2C0 to access EEPROM */
    I2C0_Init();

    g_u8DeviceAddr = 0x50;

    for (i = 0; i < 2; i++)
    {
        g_au8TxData[0] = (uint8_t)((i & 0xFF00) >> 8);
        g_au8TxData[1] = (uint8_t)(i & 0x00FF);
        g_au8TxData[2] = (uint8_t)(g_au8TxData[1] + 3);

        g_u8DataLen = 0;
        g_u8EndFlag = 0;

        /* I2C function to write data to slave */
        s_pfnI2C0Handler = (I2C_FUNC)I2C_MasterTx;

        /* I2C as master sends START signal */
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STA);

        /* Wait I2C Tx Finish */
        while (g_u8EndFlag == 0);

        g_u8EndFlag = 0;

        /* Make sure I2C0 STOP already */
        while (I2C0->CTL0 & I2C_CTL0_STO_Msk);

        /* Wait write operation complete */
        CLK_SysTickDelay(10000);

        /* I2C function to read data from slave */
        s_pfnI2C0Handler = (I2C_FUNC)I2C_MasterRx;

        g_u8DataLen = 0;
        g_u8DeviceAddr = 0x50;

        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_STA);

        /* Wait I2C Rx Finish */
        while (g_u8EndFlag == 0);

        /* Make sure I2C0 STOP already */
        while (I2C0->CTL0 & I2C_CTL0_STO_Msk);

        /* Compare data */
        if (g_u8RxData != g_au8TxData[2])
        {
            printf("I2C Byte Write/Read Failed, Data 0x%x\n", g_u8RxData);
            return -1;
        }
    }

    printf("I2C Access EEPROM Test OK\n");

    while (1);
}
