Subversion Repositories openrisc

/* ----------------------------------------------------------------------------

 *         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.

 * ----------------------------------------------------------------------------

 */

//------------------------------------------------------------------------------

/// \dir

/// !Purpose

/// 

/// Definitions for SPI peripheral usage.

///

/// !Usage

///

/// -# Enable the SPI pins required by the application (see pio.h).

/// -# Configure the SPI using the SPI_Configure function. This enables the

///    peripheral clock. The mode register is loaded with the given value.

/// -# Configure all the necessary chip selects with SPI_ConfigureNPCS.

/// -# Enable the SPI by calling SPI_Enable.

/// -# Send/receive data using SPI_Write and SPI_Read. Note that SPI_Read

///    must be called after SPI_Write to retrieve the last value read.

/// -# Send/receive data using the PDC with the SPI_WriteBuffer and

///    SPI_ReadBuffer functions.

/// -# Disable the SPI by calling SPI_Disable.

//------------------------------------------------------------------------------

#ifndef SPI_H

#define SPI_H

//------------------------------------------------------------------------------

//         Headers

//------------------------------------------------------------------------------

#include <board.h>

//------------------------------------------------------------------------------

//         Definitions

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

/// \page "SPI configuration macros"

/// This page lists several macros which should be used when configuring a SPI

/// peripheral.

/// 

/// !Macros

/// - SPI_PCS

/// - SPI_SCBR

/// - SPI_DLYBS

/// - SPI_DLYBCT

/// Calculate the PCS field value given the chip select NPCS value

#define SPI_PCS(npcs)       ((~(1 << npcs) & 0xF) << 16)

/// Calculates the value of the CSR SCBR field given the baudrate and MCK.

#define SPI_SCBR(baudrate, masterClock) \

            ((unsigned int) (masterClock / baudrate) << 8)

/// Calculates the value of the CSR DLYBS field given the desired delay (in ns)

#define SPI_DLYBS(delay, masterClock) \

            ((unsigned int) (((masterClock / 1000000) * delay) / 1000) << 16)

/// Calculates the value of the CSR DLYBCT field given the desired delay (in ns)

#define SPI_DLYBCT(delay, masterClock) \

            ((unsigned int) (((masterClock / 1000000) * delay) / 32000) << 16)

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

//         Exported functions

//------------------------------------------------------------------------------

extern void SPI_Enable(AT91S_SPI *spi);

extern void SPI_Disable(AT91S_SPI *spi);

extern void SPI_Configure(AT91S_SPI *spi,

                                 unsigned int id,

                                 unsigned int configuration);

extern void SPI_ConfigureNPCS(AT91S_SPI *spi,

                                     unsigned int npcs,

                                     unsigned int configuration);

extern void SPI_Write(AT91S_SPI *spi, unsigned int npcs, unsigned short data);

extern unsigned char SPI_WriteBuffer(AT91S_SPI *spi,

                                            void *buffer,

                                            unsigned int length);

extern unsigned char SPI_IsFinished(AT91S_SPI *pSpi);

extern unsigned short SPI_Read(AT91S_SPI *spi);

extern unsigned char SPI_ReadBuffer(AT91S_SPI *spi,

                                           void *buffer,

                                           unsigned int length);

#endif //#ifndef SPI_H