From 044ad7c3987460ede48ff27afd6bdb0ca05a0432 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Mon, 4 Jul 2011 20:52:54 +0200 Subject: import at91lib from at91lib_20100901_softpack_1_9_v_1_0_svn_v15011 it's sad to see that atmel doesn't publish their svn repo or has a centralized location or even puts proper version/release info into the library itself --- peripherals/usart/usart.c | 313 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 313 insertions(+) create mode 100644 peripherals/usart/usart.c (limited to 'peripherals/usart/usart.c') diff --git a/peripherals/usart/usart.c b/peripherals/usart/usart.c new file mode 100644 index 0000000..bbd6df5 --- /dev/null +++ b/peripherals/usart/usart.c @@ -0,0 +1,313 @@ +/* ---------------------------------------------------------------------------- + * ATMEL Microcontroller Software Support + * ---------------------------------------------------------------------------- + * Copyright (c) 2008, Atmel Corporation + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * - Redistributions of source code must retain the above copyright notice, + * this list of conditions and the disclaimer below. + * + * Atmel's name may not be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE + * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, + * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * ---------------------------------------------------------------------------- + */ + +//------------------------------------------------------------------------------ +// Headers +//------------------------------------------------------------------------------ + +#include "usart.h" +#include +#include + +//------------------------------------------------------------------------------ +// Exported functions +//------------------------------------------------------------------------------ +//------------------------------------------------------------------------------ +/// Configures an USART peripheral with the specified parameters. +/// \param usart 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(AT91S_USART *usart, + unsigned int mode, + unsigned int baudrate, + unsigned int masterClock) +{ + // Reset and disable receiver & transmitter + usart->US_CR = AT91C_US_RSTRX | AT91C_US_RSTTX + | AT91C_US_RXDIS | AT91C_US_TXDIS; + + // Configure mode + usart->US_MR = mode; + + // Configure baudrate + // Asynchronous, no oversampling + if (((mode & AT91C_US_SYNC) == 0) + && ((mode & AT91C_US_OVER) == 0)) { + + usart->US_BRGR = (masterClock / baudrate) / 16; + } + // TODO other modes +} + +//------------------------------------------------------------------------------ +/// Enables or disables the transmitter of an USART peripheral. +/// \param usart Pointer to an USART peripheral +/// \param enabled If true, the transmitter is enabled; otherwise it is +/// disabled. +//------------------------------------------------------------------------------ +void USART_SetTransmitterEnabled(AT91S_USART *usart, + unsigned char enabled) +{ + if (enabled) { + + usart->US_CR = AT91C_US_TXEN; + } + else { + + usart->US_CR = AT91C_US_TXDIS; + } +} + +//------------------------------------------------------------------------------ +/// Enables or disables the receiver of an USART peripheral +/// \param usart Pointer to an USART peripheral +/// \param enabled If true, the receiver is enabled; otherwise it is disabled. +//------------------------------------------------------------------------------ +void USART_SetReceiverEnabled(AT91S_USART *usart, + unsigned char enabled) +{ + if (enabled) { + + usart->US_CR = AT91C_US_RXEN; + } + else { + + usart->US_CR = AT91C_US_RXDIS; + } +} + +//------------------------------------------------------------------------------ +/// 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 usart 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( + AT91S_USART *usart, + unsigned short data, + volatile unsigned int timeOut) +{ + if (timeOut == 0) { + + while ((usart->US_CSR & AT91C_US_TXEMPTY) == 0); + } + else { + + while ((usart->US_CSR & AT91C_US_TXEMPTY) == 0) { + + if (timeOut == 0) { + + TRACE_ERROR("USART_Write: Timed out.\n\r"); + return; + } + timeOut--; + } + } + + usart->US_THR = data; +} + +//------------------------------------------------------------------------------ +/// Sends the contents of a data buffer through the specified USART peripheral. +/// This function returns immediately (1 if the buffer has been queued, 0 +/// otherwise); poll the ENDTX and TXBUFE bits of the USART status register +/// to check for the transfer completion. +/// \param usart Pointer to an USART peripheral. +/// \param buffer Pointer to the data buffer to send. +/// \param size Size of the data buffer (in bytes). +//------------------------------------------------------------------------------ +unsigned char USART_WriteBuffer( + AT91S_USART *usart, + void *buffer, + unsigned int size) +{ + // Check if the first PDC bank is free + if ((usart->US_TCR == 0) && (usart->US_TNCR == 0)) { + + usart->US_TPR = (unsigned int) buffer; + usart->US_TCR = size; + usart->US_PTCR = AT91C_PDC_TXTEN; + + return 1; + } + // Check if the second PDC bank is free + else if (usart->US_TNCR == 0) { + + usart->US_TNPR = (unsigned int) buffer; + usart->US_TNCR = size; + + return 1; + } + else { + + return 0; + } +} + +//------------------------------------------------------------------------------ +/// 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 usart Pointer to an USART peripheral. +/// \param timeOut Time out value (0 -> no timeout). +//------------------------------------------------------------------------------ +unsigned short USART_Read( + AT91S_USART *usart, + volatile unsigned int timeOut) +{ + if (timeOut == 0) { + + while ((usart->US_CSR & AT91C_US_RXRDY) == 0); + } + else { + + while ((usart->US_CSR & AT91C_US_RXRDY) == 0) { + + if (timeOut == 0) { + + TRACE_ERROR("USART_Read: Timed out.\n\r"); + return 0; + } + timeOut--; + } + } + + return usart->US_RHR; +} + +//------------------------------------------------------------------------------ +/// Reads data from an USART peripheral, filling the provided buffer until it +/// becomes full. This function returns immediately with 1 if the buffer has +/// been queued for transmission; otherwise 0. +/// \param usart Pointer to an USART peripheral. +/// \param buffer Pointer to the buffer where the received data will be stored. +/// \param size Size of the data buffer (in bytes). +//------------------------------------------------------------------------------ +unsigned char USART_ReadBuffer(AT91S_USART *usart, + void *buffer, + unsigned int size) +{ + // Check if the first PDC bank is free + if ((usart->US_RCR == 0) && (usart->US_RNCR == 0)) { + + usart->US_RPR = (unsigned int) buffer; + usart->US_RCR = size; + usart->US_PTCR = AT91C_PDC_RXTEN; + + return 1; + } + // Check if the second PDC bank is free + else if (usart->US_RNCR == 0) { + + usart->US_RNPR = (unsigned int) buffer; + usart->US_RNCR = size; + + return 1; + } + else { + + return 0; + } +} + +//------------------------------------------------------------------------------ +/// Returns 1 if some data has been received and can be read from an USART; +/// otherwise returns 0. +/// \param usart Pointer to an AT91S_USART instance. +//------------------------------------------------------------------------------ +unsigned char USART_IsDataAvailable(AT91S_USART *usart) +{ + if ((usart->US_CSR & AT91C_US_RXRDY) != 0) { + + return 1; + } + else { + + return 0; + } +} + +//------------------------------------------------------------------------------ +/// Sets the filter value for the IRDA demodulator. +/// \param pUsart Pointer to an AT91S_USART instance. +/// \param filter Filter value. +//------------------------------------------------------------------------------ +void USART_SetIrdaFilter(AT91S_USART *pUsart, unsigned char filter) +{ + SANITY_CHECK(pUsart); + + pUsart->US_IF = filter; +} + +//------------------------------------------------------------------------------ +/// 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 usart 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_PutChar( + AT91S_USART *usart, + unsigned char c) +{ + // Wait for the transmitter to be ready + while ((usart->US_CSR & AT91C_US_TXEMPTY) == 0); + + // Send character + usart->US_THR = c; + + // Wait for the transfer to complete + while ((usart->US_CSR & AT91C_US_TXEMPTY) == 0); +} + +//------------------------------------------------------------------------------ +/// Return 1 if a character can be read in USART +//------------------------------------------------------------------------------ +unsigned int USART_IsRxReady(AT91S_USART *usart) +{ + return (usart->US_CSR & AT91C_US_RXRDY); +} + +//------------------------------------------------------------------------------ +/// Reads and returns a character from the USART. +/// \note This function is synchronous (i.e. uses polling). +/// \return Character received. +//------------------------------------------------------------------------------ +unsigned char USART_GetChar(AT91S_USART *usart) +{ + while ((usart->US_CSR & AT91C_US_RXRDY) == 0); + return usart->US_RHR; +} \ No newline at end of file -- cgit v1.2.3