source: rtems/bsps/arm/atsam/contrib/libraries/libchip/source/uart.c @ 54aabb7

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/**
 * \file
 *
 * Implementation of UART (Universal Asynchronous Receiver Transmitter)
 * controller.
 *
 */
/*------------------------------------------------------------------------------
 *         Headers
 *----------------------------------------------------------------------------*/
#include "chip.h"

#include <assert.h>
#include <string.h>

/*------------------------------------------------------------------------------
 *         Exported functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Configures an UART peripheral with the specified parameters.
 *
 *
 *  \param uart  Pointer to the UART peripheral to configure.
 *  \param mode  Desired value for the UART mode register (see the datasheet).
 *  \param baudrate  Baudrate at which the UART should operate (in Hz).
 *  \param masterClock  Frequency of the system master clock (in Hz).
 */
void UART_Configure(Uart *uart,
                                        uint32_t mode,
                                        uint32_t baudrate,
                                        uint32_t masterClock)
{
        /* Reset and disable receiver & transmitter*/
        uart->UART_CR = UART_CR_RSTRX | UART_CR_RSTTX
                                        | UART_CR_RXDIS | UART_CR_TXDIS | UART_CR_RSTSTA;

        uart->UART_IDR = 0xFFFFFFFF;

        /* Configure mode*/
        uart->UART_MR = mode;

        /* Configure baudrate*/
        uart->UART_BRGR = (masterClock / baudrate) / 16;

        uart->UART_CR = UART_CR_TXEN | UART_CR_RXEN;

}
/**
 * \brief Enables or disables the transmitter of an UART peripheral.
 *
 *
 * \param uart  Pointer to an UART peripheral
 * \param enabled  If true, the transmitter is enabled; otherwise it is
 *  disabled.
 */
void UART_SetTransmitterEnabled(Uart *uart, uint8_t enabled)
{
        if (enabled)
                uart->UART_CR = UART_CR_TXEN;
        else
                uart->UART_CR = UART_CR_TXDIS;
}

/**
 * \brief Enables or disables the receiver of an UART peripheral
 *
 *
 * \param uart  Pointer to an UART peripheral
 * \param enabled  If true, the receiver is enabled; otherwise it is disabled.
 */
void UART_SetReceiverEnabled(Uart *uart, uint8_t enabled)
{
        if (enabled)
                uart->UART_CR = UART_CR_RXEN;
        else
                uart->UART_CR = UART_CR_RXDIS;
}

/**
 * \brief   Return 1 if a character can be read in UART
 * \param uart  Pointer to an UART peripheral.
 */
uint32_t UART_IsRxReady(Uart *uart)
{
        return (uart->UART_SR & UART_SR_RXRDY);
}

/**
 * \brief  Reads and returns a character from the UART.
 *
 * \note This function is synchronous (i.e. uses polling).
 * \param uart  Pointer to an UART peripheral.
 * \return Character received.
 */
uint8_t UART_GetChar(Uart *uart)
{
        while (!UART_IsRxReady(uart));

        return uart->UART_RHR;
}

/**
 * \brief   Return 1 if a character can be send to UART
 * \param uart  Pointer to an UART peripheral.
 */
uint32_t UART_IsTxReady(Uart *uart)
{
        return (uart->UART_SR & UART_SR_TXRDY);
}

/**
 * \brief   Return 1 if a character can be send to UART
 * \param uart  Pointer to an UART peripheral.
 */
static uint32_t UART_IsTxSent(Uart *uart)
{
        return (uart->UART_SR & UART_SR_TXEMPTY);
}

/**
 * \brief  Sends one packet of data through the specified UART peripheral. This
 * function operates synchronously, so it only returns when the data has been
 * actually sent.
 *
 * \param uart  Pointer to an UART peripheral.
 * \param c  Character to send
 */
void UART_PutChar(Uart *uart, uint8_t c)
{
        /* Wait for the transmitter to be ready*/
        while (!UART_IsRxReady(uart) && !UART_IsTxSent(uart));

        /* Send character*/
        uart->UART_THR = c;

        /* Wait for the transfer to complete*/
        while (!UART_IsTxSent(uart));
}

/**
 * \brief   Get present status
 * \param uart  Pointer to an UART peripheral.
 */
uint32_t UART_GetStatus(Uart *uart)
{
        return uart->UART_SR;
}

/**
 * \brief   Enable interrupt
 * \param uart  Pointer to an UART peripheral.
 * \param mode  Interrupt mode.
 */
void UART_EnableIt(Uart *uart, uint32_t mode)
{
        uart->UART_IER = mode;
}

/**
 * \brief   Disable interrupt
 * \param uart  Pointer to an UART peripheral.
 * \param mode  Interrupt mode.
 */
void UART_DisableIt(Uart *uart, uint32_t mode)
{
        uart->UART_IDR = mode;
}

/**
 * \brief   Return interrupt mask
 * \param uart  Pointer to an UART peripheral.
 */
uint32_t UART_GetItMask(Uart *uart)
{
        return uart->UART_IMR;
}

void UART_SendBuffer(Uart *uart, uint8_t *pBuffer, uint32_t BuffLen)
{
        uint8_t *pData = pBuffer;
        uint32_t Len = 0;

        for (Len = 0; Len < BuffLen; Len++) {
                UART_PutChar(uart, *pData);
                pData++;
        }
}

void UART_ReceiveBuffer(Uart *uart, uint8_t *pBuffer, uint32_t BuffLen)
{
        uint32_t Len = 0;

        for (Len = 0; Len < BuffLen; Len++) {
                *pBuffer = UART_GetChar(uart);
                pBuffer++;
        }
}

void UART_CompareConfig(Uart *uart, uint8_t Val1, uint8_t Val2)
{
        uart->UART_CMPR = (UART_CMPR_VAL1(Val1) | UART_CMPR_VAL2(Val2));
}