File content as of revision 0:22be4d425fdb:

#include "nvt_rs485.h"
#include "PeripheralPins.h"

NvtRS485::NvtRS485(PinName tx, PinName rx, PinName dir, E_PFM pfm)
    : Serial(tx, rx), m_ePFMID(pfm)
{
    this->set_rs485_mode(dir);
}

NvtRS485::~NvtRS485()
{
    
}

int NvtRS485::set_rs485_mode(PinName dir)
{
    int ret=0;
    mbed::SerialBase *ptrSerialBase = (mbed::SerialBase *)this;
    serial_t *obj = &_serial;
    UART_T *uart_base = (UART_T *) NU_MODBASE(obj->serial.uart);

    lock();    
    // First, disable flow control completely.
    uart_base->INTEN &= ~(UART_INTEN_ATORTSEN_Msk | UART_INTEN_ATOCTSEN_Msk);

    //Implement RS485 mode for various platform of Nuvoton
    switch (m_ePFMID) {
        case NUC472: {
            /*
            Program Sequence example:
                1. Program FUNCSEL in UART_FUNCSEL to select RS-485 function.
                2. Program the RXOFF bit (UART_FIFO[8]) to determine enable or disable RS-485 receiver
                3. Program the RS-485_NMM or RS-485_AAD mode.
                4. If the RS-485_AAD mode is selected, the ADDRMV (UART_ALTCTL[31:24]) is programmed for auto address match value.
                5. Determine auto direction control by programming RS-485_AUD.
            */

            // Check if RTS pin matches.
            uint32_t uart_rts = pinmap_peripheral(dir, PinMap_UART_RTS);
            MBED_ASSERT(uart_rts == obj->serial.uart);

            // Enable the pin for RTS function
            pinmap_pinout(dir, PinMap_UART_RTS);

            uart_base->FUNCSEL = (uart_base->FUNCSEL & ~UART_FUNCSEL_FUNCSEL_Msk) | 0x3;
            uart_base->ALTCTL  = (uart_base->ALTCTL & ~UART_ALTCTL_RS485AUD_Msk) | UART_ALTCTL_RS485AUD_Msk;

            // nRTS pin output is high level active
            //uart_base->MODEM = (uart_base->MODEM & ~UART_MODEM_RTSACTLV_Msk) | UART_MODEM_RTSACTLV_Msk;
            uart_base->MODEM = (uart_base->MODEM & ~UART_MODEM_RTSACTLV_Msk);
            //uart_base->FIFO = (uart_base->FIFO & ~UART_FIFO_RTSTRGLV_Msk);
            uart_base->FIFO = (uart_base->FIFO & ~UART_FIFO_RTSTRGLV_Msk) | (0x2 << UART_FIFO_RTSTRGLV_Pos);

            // Enable RTS
            //uart_base->INTEN |= UART_INTEN_ATORTSEN_Msk;
        }
        break;
        
        default:
            break;
    } 
    unlock();
    
    return ret;
}