
/****************************************************************************//**
 * @file     main.c
 * @version  V0.10
 * @brief    Show how to wake up MCU from Power-down mode through I2C interface.
 *           This sample code needs to work with I2C_Master.
 *
 * SPDX-License-Identifier: Apache-2.0
 * @copyright (C) 2020 Nuvoton Technology Corp. All rights reserved.
*****************************************************************************/
#include <stdio.h>
#include "NuMicro.h"

#define DEBUG_PORT   UART4

uint32_t g_u32Slave_buff_addr;
uint8_t g_au8SlvData[256];
uint8_t g_au8SlvRxData[3];
volatile uint8_t g_u8SlvI2CWK;
/*---------------------------------------------------------------------------------------------------------*/
/* Global variables                                                                                        */
/*---------------------------------------------------------------------------------------------------------*/
uint8_t g_u8DeviceAddr;
uint8_t g_u8SlvDataLen;

typedef void (*I2C_FUNC)(uint32_t u32Status);

static I2C_FUNC s_pfnI2C0Handler = NULL;

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

    /* Check I2C Wake-up interrupt flag set or not */
    if (I2C_GET_WAKEUP_FLAG(I2C0))
    {

        /* Make sure that the ACK bit is done */
        while (!(I2C0->WKSTS & I2C_WKSTS_WKAKDONE_Msk)) {};

        /* Clear I2C Wake-up interrupt flag */
        I2C_CLEAR_WAKEUP_FLAG(I2C0);

        I2C0->WKSTS = I2C_WKSTS_WKAKDONE_Msk;

        g_u8SlvI2CWK = 1;

        return;
    }

    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);
    }
}

/*---------------------------------------------------------------------------------------------------------*/
/*  Function for System Entry to Power Down Mode                                                           */
/*---------------------------------------------------------------------------------------------------------*/
void PowerDownFunction(void)
{
    /* Check if all the debug messages are finished */
    UART_WAIT_TX_EMPTY(DEBUG_PORT);

    /* Enter to Power-down mode */
    CLK_PowerDown();
}

/*---------------------------------------------------------------------------------------------------------*/
/*  I2C Slave Transmit/Receive Callback Function                                                           */
/*---------------------------------------------------------------------------------------------------------*/
void I2C_SlaveTRx(uint32_t u32Status)
{
    if (u32Status == 0x60)                      /* Own SLA+W has been receive; ACK has been return */
    {
        g_u8SlvDataLen = 0;
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);
    }
    else if (u32Status == 0x80)                 /* Previously address with own SLA address
                                                   Data has been received; ACK has been returned*/
    {
        g_au8SlvRxData[g_u8SlvDataLen] = (unsigned char)I2C_GET_DATA(I2C0);
        g_u8SlvDataLen++;

        if (g_u8SlvDataLen == 2)
        {
            g_u32Slave_buff_addr = (g_au8SlvRxData[0] << 8) + g_au8SlvRxData[1];
        }

        if (g_u8SlvDataLen == 3)
        {
            g_au8SlvData[g_u32Slave_buff_addr] = g_au8SlvRxData[2];
            g_u8SlvDataLen = 0;
        }

        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);
    }
    else if (u32Status == 0xA8)                 /* Own SLA+R has been receive; ACK has been return */
    {
        I2C_SET_DATA(I2C0, g_au8SlvData[g_u32Slave_buff_addr]);
        g_u32Slave_buff_addr++;
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);
    }
    else if (u32Status == 0xC0)                 /* Data byte or last data in I2CDAT has been transmitted
                                                   Not ACK has been received */
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);
    }
    else if (u32Status == 0x88)                 /* Previously addressed with own SLA address; NOT ACK has
                                                   been returned */
    {
        g_u8SlvDataLen = 0;
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);
    }
    else if (u32Status == 0xA0)                 /* A STOP or repeated START has been received while still
                                                   addressed as Slave/Receiver*/
    {
        g_u8SlvDataLen = 0;
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);
    }
    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 I2C module and set bus clock */
    I2C_Open(I2C0, 100000);

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

    /* Set I2C 4 Slave Addresses */
    I2C_SetSlaveAddr(I2C0, 0, 0x15, 0);   /* Slave Address : 0x15 */
    I2C_SetSlaveAddr(I2C0, 1, 0x35, 0);   /* Slave Address : 0x35 */
    I2C_SetSlaveAddr(I2C0, 2, 0x55, 0);   /* Slave Address : 0x55 */
    I2C_SetSlaveAddr(I2C0, 3, 0x75, 0);   /* Slave Address : 0x75 */

    /* Set I2C 4 Slave Addresses Mask */
    I2C_SetSlaveAddrMask(I2C0, 0, 0x01);
    I2C_SetSlaveAddrMask(I2C0, 1, 0x04);
    I2C_SetSlaveAddrMask(I2C0, 2, 0x01);
    I2C_SetSlaveAddrMask(I2C0, 3, 0x04);

    /* Enable I2C interrupt */
    I2C_EnableInt(I2C0);
    NVIC_EnableIRQ(I2C0_IRQn);
}

void I2C0_Close(void)
{
    /* Disable I2C0 interrupt and clear corresponding NVIC bit */
    I2C_DisableInt(I2C0);
    NVIC_DisableIRQ(I2C0_IRQn);

    /* Disable I2C0 and close I2C0 clock */
    I2C_Close(I2C0);
    CLK_DisableModuleClock(I2C0_MODULE);

}

/*---------------------------------------------------------------------------------------------------------*/
/*  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();

    /* Lock protected registers */
    SYS_LockReg();

    /* Configure UART for message printing. */
    UartDebugInit();

    /*
        This sample code is I2C SLAVE mode and it simulates EEPROM function
    */
    printf("\n");
    printf("+----------------------------------------------------------------------+\n");
    printf("| I2C Driver Sample Code (Slave) for wake-up & access Slave test       |\n");
    printf("|                                                                      |\n");
    printf("| I2C Master (I2C0) <---> I2C Slave(I2C0)                              |\n");
    printf("+----------------------------------------------------------------------+\n");

    printf("Configure I2C0 as a slave.\n");
    printf("The I/O connection for I2C0:\n");

    /* Init I2C0 */
    I2C0_Init();

    for (i = 0; i < 0x100; i++)
    {
        g_au8SlvData[i] = 0;
    }

    /* I2C function to Transmit/Receive data as slave */
    s_pfnI2C0Handler = I2C_SlaveTRx;

    /* Set I2C0 enter Not Address SLAVE mode */
    I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI_AA);

    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Enable I2C wake-up */
    I2C_EnableWakeup(I2C0);
    g_u8SlvI2CWK = 0;

    printf("\n");
    printf("\n");
    printf("CHIP enter power down status.\n");

    if (((I2C0->CTL0)&I2C_CTL0_SI_Msk) != 0)
    {
        I2C_SET_CONTROL_REG(I2C0, I2C_CTL_SI);
    }

    /* Enter to Power-down mode */
    PowerDownFunction();

    /* Waiting for syteem wake-up and I2C wake-up finish*/
    while (!g_u8SlvI2CWK);

    /* Lock protected registers */
    SYS_LockReg();

    printf("\n");
    printf("Slave wake-up from power down status.\n");

    printf("\n");
    printf("Slave Waiting for receiving data.\n");

    while (1);
}
