| /* ---------------------------------------------------------------------------- |
| * ATMEL Microcontroller Software Support |
| * ---------------------------------------------------------------------------- |
| * Copyright (c) 2009, 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 |
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| * ---------------------------------------------------------------------------- |
| */ |
| |
| /** \addtogroup spi_module Working with SPI |
| * The SPI driver provides the interface to configure and use the SPI |
| * peripheral. |
| * |
| * The Serial Peripheral Interface (SPI) circuit is a synchronous serial |
| * data link that provides communication with external devices in Master |
| * or Slave Mode. |
| * |
| * To use the SPI, the user has to follow these few steps: |
| * -# Enable the SPI pins required by the application (see pio.h). |
| * -# Configure the SPI using the \ref SPI_Configure(). This enables the |
| * peripheral clock. The mode register is loaded with the given value. |
| * -# Configure all the necessary chip selects with \ref SPI_ConfigureNPCS(). |
| * -# Enable the SPI by calling \ref SPI_Enable(). |
| * -# Send/receive data using \ref SPI_Write() and \ref SPI_Read(). Note that \ref SPI_Read() |
| * must be called after \ref SPI_Write() to retrieve the last value read. |
| * -# Send/receive data using the PDC with the \ref SPI_WriteBuffer() and |
| * \ref SPI_ReadBuffer() functions. |
| * -# Disable the SPI by calling \ref SPI_Disable(). |
| * |
| * For more accurate information, please look at the SPI section of the |
| * Datasheet. |
| * |
| * Related files :\n |
| * \ref spi.c\n |
| * \ref spi.h.\n |
| */ |
| /*@{*/ |
| /*@}*/ |
| |
| /** |
| * \file |
| * |
| * Implementation of Serial Peripheral Interface (SPI) controller. |
| * |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| * Headers |
| *----------------------------------------------------------------------------*/ |
| |
| #include "chip.h" |
| #include "pmc.h" |
| #include "spi.h" |
| |
| #include <stdint.h> |
| |
| /*---------------------------------------------------------------------------- |
| * Exported functions |
| *----------------------------------------------------------------------------*/ |
| |
| /** |
| * \brief Enables a SPI peripheral. |
| * |
| * \param spi Pointer to an Spi instance. |
| */ |
| extern void SPI_Enable( Spi* spi ) |
| { |
| spi->SPI_CR = SPI_CR_SPIEN ; |
| } |
| |
| /** |
| * \brief Disables a SPI peripheral. |
| * |
| * \param spi Pointer to an Spi instance. |
| */ |
| extern void SPI_Disable( Spi* spi ) |
| { |
| spi->SPI_CR = SPI_CR_SPIDIS ; |
| } |
| |
| /** |
| * \brief Enables one or more interrupt sources of a SPI peripheral. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param sources Bitwise OR of selected interrupt sources. |
| */ |
| extern void SPI_EnableIt( Spi* spi, uint32_t dwSources ) |
| { |
| spi->SPI_IER = dwSources ; |
| } |
| |
| /** |
| * \brief Disables one or more interrupt sources of a SPI peripheral. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param sources Bitwise OR of selected interrupt sources. |
| */ |
| extern void SPI_DisableIt( Spi* spi, uint32_t dwSources ) |
| { |
| spi->SPI_IDR = dwSources ; |
| } |
| |
| /** |
| * \brief Configures a SPI peripheral as specified. The configuration can be computed |
| * using several macros (see \ref spi_configuration_macros). |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param id Peripheral ID of the SPI. |
| * \param configuration Value of the SPI configuration register. |
| */ |
| extern void SPI_Configure( Spi* spi, uint32_t dwId, uint32_t dwConfiguration ) |
| { |
| PMC_EnablePeripheral( dwId ) ; |
| spi->SPI_CR = SPI_CR_SPIDIS ; |
| |
| /* Execute a software reset of the SPI twice */ |
| spi->SPI_CR = SPI_CR_SWRST ; |
| spi->SPI_CR = SPI_CR_SWRST ; |
| spi->SPI_MR = dwConfiguration ; |
| } |
| |
| |
| /** |
| * \brief Configures a chip select of a SPI peripheral. The chip select configuration |
| * is computed using several macros (see \ref spi_configuration_macros). |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param npcs Chip select to configure (0, 1, 2 or 3). |
| * \param configuration Desired chip select configuration. |
| */ |
| void SPI_ConfigureNPCS( Spi* spi, uint32_t dwNpcs, uint32_t dwConfiguration ) |
| { |
| spi->SPI_CSR[dwNpcs] = dwConfiguration ; |
| } |
| |
| /** |
| * \brief Get the current status register of the given SPI peripheral. |
| * \note This resets the internal value of the status register, so further |
| * read may yield different values. |
| * \param spi Pointer to a Spi instance. |
| * \return SPI status register. |
| */ |
| extern uint32_t SPI_GetStatus( Spi* spi ) |
| { |
| return spi->SPI_SR ; |
| } |
| |
| /** |
| * \brief Reads and returns the last word of data received by a SPI peripheral. This |
| * method must be called after a successful SPI_Write call. |
| * |
| * \param spi Pointer to an Spi instance. |
| * |
| * \return readed data. |
| */ |
| extern uint32_t SPI_Read( Spi* spi ) |
| { |
| while ( (spi->SPI_SR & SPI_SR_RDRF) == 0 ) ; |
| |
| return spi->SPI_RDR & 0xFFFF ; |
| } |
| |
| /** |
| * \brief Sends data through a SPI peripheral. If the SPI is configured to use a fixed |
| * peripheral select, the npcs value is meaningless. Otherwise, it identifies |
| * the component which shall be addressed. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param npcs Chip select of the component to address (0, 1, 2 or 3). |
| * \param data Word of data to send. |
| */ |
| extern void SPI_Write( Spi* spi, uint32_t dwNpcs, uint16_t wData ) |
| { |
| /* Send data */ |
| while ( (spi->SPI_SR & SPI_SR_TXEMPTY) == 0 ) ; |
| spi->SPI_TDR = wData | SPI_PCS( dwNpcs ) ; |
| while ( (spi->SPI_SR & SPI_SR_TDRE) == 0 ) ; |
| } |
| |
| /** |
| * \brief Check if SPI transfer finish. |
| * |
| * \param spi Pointer to an Spi instance. |
| * |
| * \return Returns 1 if there is no pending write operation on the SPI; otherwise |
| * returns 0. |
| */ |
| extern uint32_t SPI_IsFinished( Spi* spi ) |
| { |
| return ((spi->SPI_SR & SPI_SR_TXEMPTY) != 0) ; |
| } |
| |
| /** |
| * \brief Enable Spi PDC transmit |
| * \param spi Pointer to an Spi instance. |
| */ |
| extern void SPI_PdcEnableTx( Spi* spi ) |
| { |
| spi->SPI_PTCR = SPI_PTCR_TXTEN ; |
| } |
| |
| /** |
| * \brief Disable Spi PDC transmit |
| * \param spi Pointer to an Spi instance. |
| */ |
| extern void SPI_PdcDisableTx( Spi* spi ) |
| { |
| spi->SPI_PTCR = SPI_PTCR_TXTDIS ; |
| } |
| |
| /** |
| * \brief Enable Spi PDC receive |
| * \param spi Pointer to an Spi instance. |
| */ |
| extern void SPI_PdcEnableRx( Spi* spi ) |
| { |
| spi->SPI_PTCR = SPI_PTCR_RXTEN ; |
| } |
| |
| /** |
| * \brief Disable Spi PDC receive |
| * \param spi Pointer to an Spi instance. |
| */ |
| extern void SPI_PdcDisableRx( Spi* spi ) |
| { |
| spi->SPI_PTCR = SPI_PTCR_RXTDIS ; |
| } |
| |
| /** |
| * \brief Set PDC transmit and next transmit buffer address and size. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param txBuf PDC transmit buffer address. |
| * \param txCount Length in bytes of the transmit buffer. |
| * \param txNextBuf PDC next transmit buffer address. |
| * \param txNextCount Length in bytes of the next transmit buffer. |
| */ |
| extern void SPI_PdcSetTx( Spi* spi, void* pvTxBuf, uint32_t dwTxCount, void* pvTxNextBuf, uint32_t dwTxNextCount ) |
| { |
| spi->SPI_TPR = (uint32_t)pvTxBuf ; |
| spi->SPI_TCR = dwTxCount ; |
| spi->SPI_TNPR = (uint32_t)pvTxNextBuf ; |
| spi->SPI_TNCR = dwTxNextCount ; |
| } |
| |
| /** |
| * \brief Set PDC receive and next receive buffer address and size. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param rxBuf PDC receive buffer address. |
| * \param rxCount Length in bytes of the receive buffer. |
| * \param rxNextBuf PDC next receive buffer address. |
| * \param rxNextCount Length in bytes of the next receive buffer. |
| */ |
| extern void SPI_PdcSetRx( Spi* spi, void* pvRxBuf, uint32_t dwRxCount, void* pvRxNextBuf, uint32_t dwRxNextCount ) |
| { |
| spi->SPI_RPR = (uint32_t)pvRxBuf ; |
| spi->SPI_RCR = dwRxCount ; |
| spi->SPI_RNPR = (uint32_t)pvRxNextBuf ; |
| spi->SPI_RNCR = dwRxNextCount ; |
| } |
| |
| /** |
| * \brief Sends the contents of buffer through a SPI peripheral, using the PDC to |
| * take care of the transfer. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param buffer Data buffer to send. |
| * \param length Length of the data buffer. |
| */ |
| extern uint32_t SPI_WriteBuffer( Spi* spi, void* pvBuffer, uint32_t dwLength ) |
| { |
| /* Check if first bank is free */ |
| if ( spi->SPI_TCR == 0 ) |
| { |
| spi->SPI_TPR = (uint32_t)pvBuffer ; |
| spi->SPI_TCR = dwLength ; |
| spi->SPI_PTCR = PERIPH_PTCR_TXTEN ; |
| |
| return 1 ; |
| } |
| /* Check if second bank is free */ |
| else |
| { |
| if ( spi->SPI_TNCR == 0 ) |
| { |
| spi->SPI_TNPR = (uint32_t)pvBuffer ; |
| spi->SPI_TNCR = dwLength ; |
| |
| return 1 ; |
| } |
| } |
| |
| /* No free banks */ |
| return 0 ; |
| } |
| |
| /** |
| * \brief Reads data from a SPI peripheral until the provided buffer is filled. This |
| * method does NOT need to be called after SPI_Write or SPI_WriteBuffer. |
| * |
| * \param spi Pointer to an Spi instance. |
| * \param buffer Data buffer to store incoming bytes. |
| * \param length Length in bytes of the data buffer. |
| */ |
| extern uint32_t SPI_ReadBuffer( Spi* spi, void *pvBuffer, uint32_t dwLength ) |
| { |
| /* Check if the first bank is free */ |
| if ( spi->SPI_RCR == 0 ) |
| { |
| spi->SPI_RPR = (uint32_t)pvBuffer ; |
| spi->SPI_RCR = dwLength ; |
| spi->SPI_PTCR = PERIPH_PTCR_RXTEN ; |
| |
| return 1 ; |
| } |
| /* Check if second bank is free */ |
| else |
| { |
| if ( spi->SPI_RNCR == 0 ) |
| { |
| spi->SPI_RNPR = (uint32_t)pvBuffer ; |
| spi->SPI_RNCR = dwLength ; |
| return 1 ; |
| } |
| } |
| |
| /* No free bank */ |
| return 0 ; |
| } |
| |
| |