path: root/c/src/lib/libbsp/arm/atsam/libraries/libchip/source/usart.c

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

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

/*----------------------------------------------------------------------------
 *        Local definitions
 *----------------------------------------------------------------------------*/


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

/**
 * \brief Configures an USART baudrate.
 *
 *
 *  \param pUsart  Pointer to the USART peripheral to configure.
 *  \param baudrate  Baudrate at which the USART should operate (in Hz).
 *  \param masterClock  Frequency of the system master clock (in Hz).
 */
void USART_SetBaudrate(Usart *pUsart,
					   uint8_t OverSamp,
					   uint32_t baudrate,
					   uint32_t masterClock)
{
	unsigned int CD, FP, BaudError, ActualBaudRate;
	/* Configure baudrate*/
	BaudError = 10;
	OverSamp = 0;
#ifdef __rtems__
	CD = 0;
	FP = 0;
#endif /* __rtems__ */

	/*Asynchronous*/
	if ((pUsart->US_MR & US_MR_SYNC) == 0) {
		/* 7816 mode */
		if (((pUsart->US_MR & US_MR_USART_MODE_IS07816_T_0)
			  == US_MR_USART_MODE_IS07816_T_0)
			 || ((pUsart->US_MR & US_MR_USART_MODE_IS07816_T_1)
				 == US_MR_USART_MODE_IS07816_T_1)) {
			/* Define the baud rate divisor register */
			/* CD  = MCK / SCK */
			/* SCK = FIDI x BAUD = 372 x 9600 */
			/* BOARD_MCK */
			/* CD = MCK/(FIDI x BAUD) = 150000000 / (372x9600) = 42 */
			CD = masterClock / (pUsart->US_FIDI * baudrate);
			FP = 0;
		} else {
			while (BaudError > 5) {
				CD = (masterClock / (baudrate * 8 * (2 - OverSamp)));
				FP = ((masterClock / (baudrate * (2 - OverSamp))) - CD * 8);
				ActualBaudRate = (masterClock / (CD * 8 + FP)) / (2 - OverSamp);
				BaudError = (100 - ((baudrate * 100 / ActualBaudRate)));

				if (BaudError > 5) {
					OverSamp++;

					if (OverSamp >= 2) {
						TRACE_ERROR("Canont set this baudrate \n\r");
						break;
					}
				}
			}
		}
	}

	/*Synchronous SPI  */
	if ((pUsart->US_MR & US_MR_USART_MODE_SPI_MASTER)
		== US_MR_USART_MODE_SPI_MASTER
		|| ((pUsart->US_MR & US_MR_SYNC) == US_MR_SYNC)) {
		if ((pUsart->US_MR & US_MR_USCLKS_Msk) == US_MR_USCLKS_MCK) {
			CD = masterClock / baudrate;
			FP = ((masterClock / baudrate) - CD);
		}
	}

	pUsart->US_BRGR = (US_BRGR_CD(CD) | US_BRGR_FP(FP));

	/* Configure OverSamp*/
	pUsart->US_MR |= (OverSamp << 19);
}

/**
 * \brief Configures an USART peripheral with the specified parameters.
 *
 *
 *  \param pUsart  Pointer to the USART peripheral to configure.
 *  \param mode  Desired value for the USART mode register (see the datasheet).
 *  \param baudrate  Baudrate at which the USART should operate (in Hz).
 *  \param masterClock  Frequency of the system master clock (in Hz).
 */
void USART_Configure(Usart *pUsart,
					 uint32_t mode,
					 uint32_t baudrate,
					 uint32_t masterClock)
{

	/* Reset and disable receiver & transmitter*/
	pUsart->US_CR = US_CR_RSTRX | US_CR_RSTTX
					| US_CR_RXDIS | US_CR_TXDIS | US_CR_RSTSTA;
	pUsart->US_IDR = 0xFFFFFFFF;

	pUsart->US_MR = mode;
	/* Configure baudrate*/
	USART_SetBaudrate(pUsart, 0, baudrate, masterClock);

	/* Enable receiver and transmitter */
	pUsart->US_CR = US_CR_RXEN | US_CR_TXEN;

	/* Disable buffering for printf(). */
#if (defined (__GNUC__) && !defined (__SAMBA__))
	setvbuf(stdout, (char *)NULL, _IONBF, 0);
#endif

}
/**
 * \brief Enables or disables the transmitter of an USART peripheral.
 *
 *
 * \param pUsart  Pointer to an USART peripheral
 * \param enabled  If true, the transmitter is enabled; otherwise it is
 * disabled.
 */
void USART_SetTransmitterEnabled(Usart *pUsart, uint8_t enabled)
{
	if (enabled)
		pUsart->US_CR = US_CR_TXEN;
	else
		pUsart->US_CR = US_CR_TXDIS;
}

/**
 * \brief Disables the Receiver of an USART peripheral.
 *
 * \param pUsart  Pointer to an USART peripheral
 */
void USART_DisableRx(Usart *pUsart)
{

	pUsart->US_CR = US_CR_RXDIS;
}

/**
 * \brief Disables the transmitter of an USART peripheral.
 *
 * \param pUsart  Pointer to an USART peripheral
 */
void USART_DisableTx(Usart *pUsart)
{
	pUsart->US_CR =  US_CR_TXDIS;
}

/**
 * \brief Enables the Receiver of an USART peripheral.
 *
 * \param pUsart  Pointer to an USART peripheral
 */
void USART_EnableRx(Usart *pUsart)
{

	pUsart->US_CR = US_CR_RXEN;
}

/**
 * \brief Enables the transmitter of an USART peripheral
 *
 * \param pUsart  Pointer to an USART peripheral
 */
void USART_EnableTx(Usart *pUsart)
{
	pUsart->US_CR =  US_CR_TXEN;
}
/**
 * \brief Resets or disables the Receiver of an USART peripheral.
 *
 *
 * \param pUsart  Pointer to an USART peripheral
 */
void USART_ResetRx(Usart *pUsart)
{

	pUsart->US_CR = US_CR_RSTRX | US_CR_RXDIS;
}

/**
 * \brief resets and disables the transmitter of an USART peripheral.
 *
 *
 * \param pUsart  Pointer to an USART peripheral
 */
void USART_ResetTx(Usart *pUsart)
{
	pUsart->US_CR =  US_CR_RSTTX | US_CR_TXDIS;
}
/**
 * \brief Enables or disables the receiver of an USART peripheral
 *
 *
 * \param pUsart  Pointer to an USART peripheral
 * \param enabled  If true, the receiver is enabled; otherwise it is disabled.
 */
void USART_SetReceiverEnabled(Usart *pUsart, uint8_t enabled)
{
	if (enabled)
		pUsart->US_CR = US_CR_RXEN;
	else
		pUsart->US_CR = US_CR_RXDIS;
}

/**
 * \brief Enables or disables the Request To Send (RTS) of an USART peripheral
 *
 *
 * \param pUsart  Pointer to an USART peripheral
 * \param enabled  If true, the RTS is enabled (0); otherwise it is disabled.
 */
void USART_SetRTSEnabled(Usart *pUsart, uint8_t enabled)
{
	if (enabled)
		pUsart->US_CR = US_CR_RTSEN;
	else
		pUsart->US_CR = US_CR_RTSDIS;
}

/**
 * \brief Sends one packet of data through the specified USART peripheral. This
 * function operates synchronously, so it only returns when the data has been
 * actually sent.
 *
 *
 * \param pUsart  Pointer to an USART peripheral.
 * \param data  Data to send including 9nth bit and sync field if necessary (in
 *        the same format as the US_THR register in the datasheet).
 * \param timeOut  Time out value (0 = no timeout).
 */
void USART_Write(Usart *pUsart, uint16_t data, volatile uint32_t timeOut)
{
	if (timeOut == 0) {
		while ((pUsart->US_CSR & US_CSR_TXEMPTY) == 0);
	} else {
		while ((pUsart->US_CSR & US_CSR_TXEMPTY) == 0) {
			if (timeOut == 0) {
				TRACE_ERROR("USART_Write: Timed out.\n\r");
				return;
			}

			timeOut--;
		}
	}

	pUsart->US_THR = data;
}

/**
 * \brief  Reads and return a packet of data on the specified USART peripheral.
 * This function operates asynchronously, so it waits until some data has been
 * received.
 *
 * \param pUsart  Pointer to an USART peripheral.
 * \param timeOut  Time out value (0 -> no timeout).
 */
uint16_t USART_Read(Usart *pUsart, volatile uint32_t timeOut)
{
	if (timeOut == 0) {
		while ((pUsart->US_CSR & US_CSR_RXRDY) == 0);
	} else {
		while ((pUsart->US_CSR & US_CSR_RXRDY) == 0) {
			if (timeOut == 0) {
				TRACE_ERROR("USART_Read: Timed out.\n\r");
				return 0;
			}

			timeOut--;
		}
	}

	return pUsart->US_RHR;
}

/**
 * \brief  Returns 1 if some data has been received and can be read from an
 * USART; otherwise returns 0.
 *
 * \param pUsart  Pointer to an USART instance.
 */
uint8_t USART_IsDataAvailable(Usart *pUsart)
{
	if ((pUsart->US_CSR & US_CSR_RXRDY) != 0)
		return 1;
	else
		return 0;
}

/**
 * \brief  Sends one packet of data through the specified USART peripheral. This
 * function operates synchronously, so it only returns when the data has been
 * actually sent.
 *
 * \param pUsart  Pointer to an USART peripheral.
 * \param c  Character to send
 */
void USART_PutChar(Usart *pUsart, uint8_t c)
{
	/* Wait for the transmitter to be ready*/
	while ((pUsart->US_CSR & US_CSR_TXEMPTY) == 0);

	/* Send character*/
	pUsart->US_THR = c;

	/* Wait for the transfer to complete*/
	while ((pUsart->US_CSR & US_CSR_TXEMPTY) == 0);
}

/**
 * \brief   Return 1 if a character can be read in USART
 * \param pUsart  Pointer to an USART peripheral.
 */
uint32_t USART_IsRxReady(Usart *pUsart)
{
	return (pUsart->US_CSR & US_CSR_RXRDY);
}

/**
 * \brief   Get present status
 * \param pUsart  Pointer to an USART peripheral.
 */
uint32_t USART_GetStatus(Usart *pUsart)
{
	return pUsart->US_CSR;
}

/**
 * \brief   Enable interrupt
 * \param pUsart  Pointer to an USART peripheral.
 * \param mode  Interrupt mode.
 */
void USART_EnableIt(Usart *pUsart, uint32_t mode)
{
	pUsart->US_IER = mode;
}

/**
 * \brief   Disable interrupt
 * \param pUsart  Pointer to an USART peripheral.
 * \param mode  Interrupt mode.
 */
void USART_DisableIt(Usart *pUsart, uint32_t mode)
{
	pUsart->US_IDR = mode;
}

/**
 * \brief   Return interrupt mask
 * \param pUsart  Pointer to an USART peripheral.
 */
uint32_t USART_GetItMask(Usart *pUsart)
{
	return pUsart->US_IMR;
}

/**
 * \brief  Reads and returns a character from the USART.
 *
 * \note This function is synchronous (i.e. uses polling).
 * \param pUsart  Pointer to an USART peripheral.
 * \return Character received.
 */
uint8_t USART_GetChar(Usart *pUsart)
{
	while ((pUsart->US_CSR & US_CSR_RXRDY) == 0);

	return pUsart->US_RHR;
}

/**
 * \brief  Enable Rx Timeout for USART.
 *
 * \param pUsart  Pointer to an USART peripheral.
 * \param Timeout  Timeout value
 * \return None
 */
void USART_EnableRecvTimeOut(Usart *pUsart, uint32_t Timeout)
{
	if (Timeout <= MAX_RX_TIMEOUT)
		pUsart->US_RTOR = Timeout;
	else if (Timeout == 0) {
		TRACE_DEBUG("Timeout is disabled\n\r");
	} else {
		TRACE_INFO_WP("\n\r");
		TRACE_FATAL("Timeout value is out of range\n\r");
	}
}

/**
 * \brief  Enable Tx Timeout for USART.
 *
 * \param pUsart  Pointer to an USART peripheral.
 * \param TimeGaurd  TimeGaurd value
 * \return None
 */
void USART_EnableTxTimeGaurd(Usart *pUsart, uint32_t TimeGaurd)
{
	if (((pUsart->US_MR & US_MR_USART_MODE_LON) && TimeGaurd <= 16777215) ||
		 ((pUsart->US_MR & US_MR_USART_MODE_LON) && TimeGaurd <= 255))
		pUsart->US_TTGR = TimeGaurd;
	else
		TRACE_ERROR(" TimeGaurd Value is too big for mode");
}
/**
 * \brief  Acknowledge Rx timeout and sets to Idle or periodic repetitive state.
 *
 * \param pUsart  Pointer to an USART peripheral.
 * \param Periodic  If timeout is periodic or should wait for new char
 * \return None
 */
void USART_AcknowledgeRxTimeOut(Usart *pUsart, uint8_t Periodic)
{
	if (Periodic) {
		pUsart->US_CR = US_CR_RETTO;     // Restart timeout timer
	} else {
		// Puts USARt in Idle mode and waits for a char after timeout
		pUsart->US_CR = US_CR_STTTO;
	}
}