//! @todo Review this document.
/*!
LT_SPI: Routines to communicate with ATmega328P's hardware SPI port.


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*/

/*! @file
    @ingroup LT_SPI
    Library Header File for LT_SPI: Routines to communicate with ATmega328P's hardware SPI port.
*/

#ifndef LT_SPI_H
#define LT_SPI_H

#include <stdint.h>
#include <SPI.h>

// Uncomment the following to use functions that implement LTC SPI routines

// //! @name SPI CLOCK DIVIDER CONSTANTS
// //! @{
// #define SPI_CLOCK_DIV4    0x00  // 4 Mhz
// #define SPI_CLOCK_DIV16   0x01  // 1 Mhz
// #define SPI_CLOCK_DIV64   0x02  // 250 khz
// #define SPI_CLOCK_DIV128  0x03  // 125 khz
// #define SPI_CLOCK_DIV2    0x04  // 8 Mhz
// #define SPI_CLOCK_DIV8    0x05  // 2 Mhz
// #define SPI_CLOCK_DIV32   0x06  // 500 khz
// //! @}
//
// //! @name SPI HARDWARE MODE CONSTANTS
// //! @{
// #define SPI_MODE0 0x00
// #define SPI_MODE1 0x04
// // #define SPI_MODE2 0x08
// #define SPI_MODE3 0x0C
// //! @}
//
// //! @name SPI SET MASKS
//! @{
// #define SPI_MODE_MASK      0x0C    // CPOL = bit 3, CPHA = bit 2 on SPCR
// #define SPI_CLOCK_MASK     0x03    // SPR1 = bit 1, SPR0 = bit 0 on SPCR
// #define SPI_2XCLOCK_MASK   0x01    // SPI2X = bit 0 on SPSR
// //! @}

//! Reads and sends a byte
//! @return void
void spi_transfer_byte(uint8_t cs_pin,      //!< Chip select pin
                       uint8_t tx,          //!< Byte to be transmitted
                       uint8_t *rx          //!< Byte to be received
                      );

//! Reads and sends a word
//! @return void
void spi_transfer_word(uint8_t cs_pin,      //!< Chip select pin
                       uint16_t tx,         //!< Byte to be transmitted
                       uint16_t *rx         //!< Byte to be received
                      );

//! Reads and sends a byte array
//! @return void
void spi_transfer_block(uint8_t cs_pin,     //!< Chip select pin
                        uint8_t *tx,        //!< Byte array to be transmitted
                        uint8_t *rx,        //!< Byte array to be received
                        uint8_t length      //!< Length of array
                       );

//! Connect SPI pins to QuikEval connector through the Linduino MUX. This will disconnect I2C.
void quikeval_SPI_connect();

//! Configure the SPI port for 4Mhz SCK.
//! This function or spi_enable() must be called
//! before using the other SPI routines.
void quikeval_SPI_init();

//! Setup the processor for hardware SPI communication.
//! Must be called before using the other SPI routines.
//! Alternatively, call quikeval_SPI_connect(), which automatically
//! calls this function.
void spi_enable(uint8_t spi_clock_divider   //!< Configures SCK frequency. Use constant defined in header file.
               );

//! Disable the SPI hardware port
void spi_disable();

//! Write a data byte using the SPI hardware
void spi_write(int8_t data  //!< Byte to be written to SPI port
              );

//! Read and write a data byte using the SPI hardware
//! @return the data byte read
int8_t spi_read(int8_t data //!< The data byte to be written
               );

#endif  // LT_SPI_H