/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 5 $
 * $Date: 15/01/16 11:44a $
 * @brief    Show how to use I2C interface to access EEPROM.
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 *
 * @copyright Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC131.h"

#define PLLCON_SETTING  CLK_PLLCON_50MHz_HXT
#define PLL_CLOCK       50000000


/*---------------------------------------------------------------------------------------------------------*/
/* Global variables                                                                                        */
/*---------------------------------------------------------------------------------------------------------*/
volatile uint8_t g_u8DeviceAddr;
volatile 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 volatile I2C_FUNC s_I2C0HandlerFn = NULL;

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

    u32Status = I2C0->I2CSTATUS;

    if(I2C0->I2CTOC & I2C_I2CTOC_TIF_Msk)
    {
        /* Clear I2C0 Timeout Flag */
        I2C0->I2CTOC |= I2C_I2CTOC_TIF_Msk;
    }
    else
    {
        if(s_I2C0HandlerFn != NULL)
            s_I2C0HandlerFn(u32Status);
    }
}

/*---------------------------------------------------------------------------------------------------------*/
/*  I2C Rx Callback Function                                                                               */
/*---------------------------------------------------------------------------------------------------------*/
void I2C_MasterRx(uint32_t u32Status)
{
    if(u32Status == 0x08)                       /* START has been transmitted and prepare SLA+W */
    {
        I2C0->I2CDAT = g_u8DeviceAddr << 1;     /* Write SLA+W to Register I2CDAT */
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
    }
    else if(u32Status == 0x18)                  /* SLA+W has been transmitted and ACK has been received */
    {
        I2C0->I2CDAT = g_au8TxData[g_u8DataLen++];
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
    }
    else if(u32Status == 0x20)                  /* SLA+W has been transmitted and NACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STA_STO_SI);
    }
    else if(u32Status == 0x28)                  /* DATA has been transmitted and ACK has been received */
    {
        if(g_u8DataLen != 2)
        {
            I2C0->I2CDAT = g_au8TxData[g_u8DataLen++];
            I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
        }
        else
        {
            I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STA_SI);
        }
    }
    else if(u32Status == 0x10)                  /* Repeat START has been transmitted and prepare SLA+R */
    {
        I2C0->I2CDAT = ((g_u8DeviceAddr << 1) | 0x01);   /* Write SLA+R to Register I2CDAT */
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
    }
    else if(u32Status == 0x40)                  /* SLA+R has been transmitted and ACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
    }
    else if(u32Status == 0x58)                  /* DATA has been received and NACK has been returned */
    {
        g_u8RxData = I2C0->I2CDAT;
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STO_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 */
    {
        I2C0->I2CDAT = g_u8DeviceAddr << 1;     /* Write SLA+W to Register I2CDAT */
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
    }
    else if(u32Status == 0x18)                  /* SLA+W has been transmitted and ACK has been received */
    {
        I2C0->I2CDAT = g_au8TxData[g_u8DataLen++];
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
    }
    else if(u32Status == 0x20)                  /* SLA+W has been transmitted and NACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STA_STO_SI);
    }
    else if(u32Status == 0x28)                  /* DATA has been transmitted and ACK has been received */
    {
        if(g_u8DataLen != 3)
        {
            I2C0->I2CDAT = g_au8TxData[g_u8DataLen++];
            I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_SI);
        }
        else
        {
            I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STO_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 22.1184MHz clock */
    CLK->PWRCON |= CLK_PWRCON_OSC22M_EN_Msk;

    /* Waiting for Internal RC clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_OSC22M_STB_Msk));

    /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
    CLK->CLKSEL0 &= ~CLK_CLKSEL0_HCLK_S_Msk;
    CLK->CLKSEL0 |= CLK_CLKSEL0_HCLK_S_HIRC;
    CLK->CLKDIV &= ~CLK_CLKDIV_HCLK_N_Msk;
    CLK->CLKDIV |= CLK_CLKDIV_HCLK(1);

    /* Enable external XTAL 12MHz clock */
    CLK->PWRCON |= CLK_PWRCON_XTL12M_EN_Msk;

    /* Waiting for external XTAL clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_XTL12M_STB_Msk));

    /* Set core clock as PLL_CLOCK from PLL */
    CLK->PLLCON = PLLCON_SETTING;
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_PLL_STB_Msk));
    CLK->CLKSEL0 &= (~CLK_CLKSEL0_HCLK_S_Msk);
    CLK->CLKSEL0 |= CLK_CLKSEL0_HCLK_S_PLL;

    /* Update System Core Clock */
    /* User can use SystemCoreClockUpdate() to calculate PllClock, SystemCoreClock and CyclesPerUs automatically. */
    //SystemCoreClockUpdate();
    PllClock        = PLL_CLOCK;            // PLL
    SystemCoreClock = PLL_CLOCK / 1;        // HCLK
    CyclesPerUs     = PLL_CLOCK / 1000000;  // For CLK_SysTickDelay()

    /* Enable UART & I2C0 module clock */
    CLK->APBCLK |= (CLK_APBCLK_UART0_EN_Msk | CLK_APBCLK_I2C0_EN_Msk);

    /* Select UART module clock source */
    CLK->CLKSEL1 &= ~CLK_CLKSEL1_UART_S_Msk;
    CLK->CLKSEL1 |= CLK_CLKSEL1_UART_S_HXT;

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Set GPB multi-function pins for UART0 RXD and TXD */
    SYS->GPB_MFP &= ~(SYS_GPB_MFP_PB0_Msk | SYS_GPB_MFP_PB1_Msk);
    SYS->GPB_MFP |= SYS_GPB_MFP_PB0_UART0_RXD | SYS_GPB_MFP_PB1_UART0_TXD;

    /* Set GPA multi-function pins for I2C0 SDA and SCL */
    SYS->GPA_MFP &= ~(SYS_GPA_MFP_PA8_Msk | SYS_GPA_MFP_PA9_Msk);
    SYS->GPA_MFP |= SYS_GPA_MFP_PA8_I2C0_SDA | SYS_GPA_MFP_PA9_I2C0_SCL;
}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART IP */
    SYS->IPRSTC2 |=  SYS_IPRSTC2_UART0_RST_Msk;
    SYS->IPRSTC2 &= ~SYS_IPRSTC2_UART0_RST_Msk;

    /* Configure UART0 and set UART0 Baudrate */
    UART0->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(__HXT, 115200);
    UART0->LCR = UART_WORD_LEN_8 | UART_PARITY_NONE | UART_STOP_BIT_1;
}

void I2C0_Init(void)
{
    uint32_t u32BusClock;
    /* Reset I2C0 */
    SYS->IPRSTC2 |=  SYS_IPRSTC2_I2C0_RST_Msk;
    SYS->IPRSTC2 &= ~SYS_IPRSTC2_I2C0_RST_Msk;

    /* Enable I2C0 Controller */
    I2C0->I2CON |= I2C_I2CON_ENS1_Msk;

    /* I2C0 bus clock 100K divider setting, I2CLK = PCLK/(100K*4)-1 */
    u32BusClock = 100000;
    I2C0->I2CLK = (uint32_t)(((SystemCoreClock * 10) / (u32BusClock * 4) + 5) / 10 - 1); /* Compute proper divider for I2C clock */

    /* Get I2C0 Bus Clock */
    printf("I2C clock %d Hz\n", (SystemCoreClock / (((I2C0->I2CLK) + 1) << 2)));

    /* Set I2C0 4 Slave Addresses */
    /* Slave Address : 0x15 */
    I2C0->I2CADDR0 = (I2C0->I2CADDR0 & ~I2C_I2CADDR_I2CADDR_Msk) | (0x15 << I2C_I2CADDR_I2CADDR_Pos);
    /* Slave Address : 0x35 */
    I2C0->I2CADDR1 = (I2C0->I2CADDR1 & ~I2C_I2CADDR_I2CADDR_Msk) | (0x35 << I2C_I2CADDR_I2CADDR_Pos);
    /* Slave Address : 0x55 */
    I2C0->I2CADDR2 = (I2C0->I2CADDR2 & ~I2C_I2CADDR_I2CADDR_Msk) | (0x55 << I2C_I2CADDR_I2CADDR_Pos);
    /* Slave Address : 0x75 */
    I2C0->I2CADDR3 = (I2C0->I2CADDR3 & ~I2C_I2CADDR_I2CADDR_Msk) | (0x75 << I2C_I2CADDR_I2CADDR_Pos);

    /* Enable I2C0 interrupt and set corresponding NVIC bit */
    I2C0->I2CON |= I2C_I2CON_EI_Msk;
    NVIC_EnableIRQ(I2C0_IRQn);
}

void I2C0_Close(void)
{
    /* Disable I2C0 interrupt and clear corresponding NVIC bit */
    I2C0->I2CON &= ~I2C_I2CON_EI_Msk;
    NVIC_DisableIRQ(I2C0_IRQn);

    /* Disable I2C0 and close I2C0 clock */
    I2C0->I2CON &= ~I2C_I2CON_ENS1_Msk;
    CLK->APBCLK &= ~CLK_APBCLK_I2C0_EN_Msk;
}

/*---------------------------------------------------------------------------------------------------------*/
/*  Main Function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
    uint32_t i, u32TimeOutCnt;

    /* Unlock protected registers */
    SYS_UnlockReg();

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

    /* Lock protected registers */
    SYS_LockReg();

    /* Init UART0 for printf */
    UART0_Init();

    /*
        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("|    NUC131 I2C Driver Sample Code with EEPROM 24LC64   |\n");
    printf("+-------------------------------------------------------+\n");

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

    g_u8DeviceAddr = 0x50;

    for(i = 0; i < 0x100; 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_I2C0HandlerFn = (I2C_FUNC)I2C_MasterTx;

        /* I2C as master sends START signal */
        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STA);

        /* Wait I2C Tx Finish */
        u32TimeOutCnt = I2C_TIMEOUT;
        while(g_u8EndFlag == 0)
        {
            if(--u32TimeOutCnt == 0)
            {
                printf("Wait for I2C Tx finish time-out!\n");
                goto lexit;
            }
        }
        g_u8EndFlag = 0;

        /* I2C function to read data from slave */
        s_I2C0HandlerFn = (I2C_FUNC)I2C_MasterRx;

        /* Set EEPROM Address */
        g_u8DataLen = 0;
        g_u8DeviceAddr = 0x50;

        I2C_SET_CONTROL_REG(I2C0, I2C_I2CON_STA);

        /* Wait I2C Rx Finish */
        u32TimeOutCnt = I2C_TIMEOUT;
        while(g_u8EndFlag == 0)
        {
            if(--u32TimeOutCnt == 0)
            {
                printf("Wait for I2C Rx finish time-out!\n");
                goto lexit;
            }
        }

        /* Compare data */
        if(g_u8RxData != g_au8TxData[2])
        {
            printf("I2C Byte Write/Read Failed, Data 0x%x\n", g_u8RxData);
            goto lexit;
        }
    }
    printf("I2C Access EEPROM Test OK\n");

lexit:

    s_I2C0HandlerFn = NULL;

    /* Close I2C0 */
    I2C0_Close();

    while(1);
}



