--- /dev/null
+/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2011.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.lufa-lib.org
+*/
+
+/*
+ Copyright 2011 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+ Permission to use, copy, modify, distribute, and sell this
+ software and its documentation for any purpose is hereby granted
+ without fee, provided that the above copyright notice appear in
+ all copies and that both that the copyright notice and this
+ permission notice and warranty disclaimer appear in supporting
+ documentation, and that the name of the author not be used in
+ advertising or publicity pertaining to distribution of the
+ software without specific, written prior permission.
+
+ The author disclaim all warranties with regard to this
+ software, including all implied warranties of merchantability
+ and fitness. In no event shall the author be liable for any
+ special, indirect or consequential damages or any damages
+ whatsoever resulting from loss of use, data or profits, whether
+ in an action of contract, negligence or other tortious action,
+ arising out of or in connection with the use or performance of
+ this software.
+*/
+
+/** \file
+ * \brief SPI Peripheral Driver (AVR8)
+ *
+ * On-chip SPI driver for the 8-bit AVR microcontrollers.
+ *
+ * \note This file should not be included directly. It is automatically included as needed by the SPI driver
+ * dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
+ */
+
+/** \ingroup Group_SPI
+ * \defgroup Group_SPI_AVR8 SPI Peripheral Driver (AVR8)
+ *
+ * \section Sec_ModDescription Module Description
+ * Driver for the hardware SPI port available on most 8-bit AVR microcontroller models. This
+ * module provides an easy to use driver for the setup and transfer of data over the
+ * AVR's SPI port.
+ *
+ * \note This file should not be included directly. It is automatically included as needed by the SPI driver
+ * dispatch header located in LUFA/Drivers/Peripheral/SPI.h.
+ *
+ * \section Sec_ExampleUsage Example Usage
+ * The following snippet is an example of how this module may be used within a typical
+ * application.
+ *
+ * \code
+ * // Initialise the SPI driver before first use
+ * SPI_Init(SPI_SPEED_FCPU_DIV_2 | SPI_ORDER_MSB_FIRST | SPI_SCK_LEAD_FALLING |
+ * SPI_SAMPLE_TRAILING | SPI_MODE_MASTER);
+ *
+ * // Send several bytes, ignoring the returned data
+ * SPI_SendByte(0x01);
+ * SPI_SendByte(0x02);
+ * SPI_SendByte(0x03);
+ *
+ * // Receive several bytes, sending a dummy 0x00 byte each time
+ * uint8_t Byte1 = SPI_ReceiveByte();
+ * uint8_t Byte2 = SPI_ReceiveByte();
+ * uint8_t Byte3 = SPI_ReceiveByte();
+ *
+ * // Send a byte, and store the received byte from the same transaction
+ * uint8_t ResponseByte = SPI_TransferByte(0xDC);
+ * \endcode
+ *
+ * @{
+ */
+
+#ifndef __SPI_AVR8_H__
+#define __SPI_AVR8_H__
+
+ /* Includes: */
+ #include "../../../Common/Common.h"
+
+ /* Enable C linkage for C++ Compilers: */
+ #if defined(__cplusplus)
+ extern "C" {
+ #endif
+
+ /* Preprocessor Checks: */
+ #if !defined(__INCLUDE_FROM_SPI_H)
+ #error Do not include this file directly. Include LUFA/Drivers/Peripheral/SPI.h instead.
+ #endif
+
+ /* Private Interface - For use in library only: */
+ #if !defined(__DOXYGEN__)
+ /* Macros: */
+ #define SPI_USE_DOUBLESPEED (1 << SPE)
+ #endif
+
+ /* Public Interface - May be used in end-application: */
+ /* Macros: */
+ /** \name SPI Prescaler Configuration Masks */
+ //@{
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 2. */
+ #define SPI_SPEED_FCPU_DIV_2 SPI_USE_DOUBLESPEED
+
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 4. */
+ #define SPI_SPEED_FCPU_DIV_4 0
+
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 8. */
+ #define SPI_SPEED_FCPU_DIV_8 (SPI_USE_DOUBLESPEED | (1 << SPR0))
+
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 16. */
+ #define SPI_SPEED_FCPU_DIV_16 (1 << SPR0)
+
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 32. */
+ #define SPI_SPEED_FCPU_DIV_32 (SPI_USE_DOUBLESPEED | (1 << SPR1))
+
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 64. */
+ #define SPI_SPEED_FCPU_DIV_64 (SPI_USE_DOUBLESPEED | (1 << SPR1) | (1 << SPR0))
+
+ /** SPI prescaler mask for \c SPI_Init(). Divides the system clock by a factor of 128. */
+ #define SPI_SPEED_FCPU_DIV_128 ((1 << SPR1) | (1 << SPR0))
+ //@}
+
+ /** \name SPI SCK Polarity Configuration Masks */
+ //@{
+ /** SPI clock polarity mask for \c SPI_Init(). Indicates that the SCK should lead on the rising edge. */
+ #define SPI_SCK_LEAD_RISING (0 << CPOL)
+
+ /** SPI clock polarity mask for \c SPI_Init(). Indicates that the SCK should lead on the falling edge. */
+ #define SPI_SCK_LEAD_FALLING (1 << CPOL)
+ //@}
+
+ /** \name SPI Sample Edge Configuration Masks */
+ //@{
+ /** SPI data sample mode mask for \c SPI_Init(). Indicates that the data should sampled on the leading edge. */
+ #define SPI_SAMPLE_LEADING (0 << CPHA)
+
+ /** SPI data sample mode mask for \c SPI_Init(). Indicates that the data should be sampled on the trailing edge. */
+ #define SPI_SAMPLE_TRAILING (1 << CPHA)
+ //@}
+
+ /** \name SPI Data Ordering Configuration Masks */
+ //@{
+ /** SPI data order mask for \c SPI_Init(). Indicates that data should be shifted out MSB first. */
+ #define SPI_ORDER_MSB_FIRST (0 << DORD)
+
+ /** SPI data order mask for \c SPI_Init(). Indicates that data should be shifted out MSB first. */
+ #define SPI_ORDER_LSB_FIRST (1 << DORD)
+ //@}
+
+ /** \name SPI Mode Configuration Masks */
+ //@{
+ /** SPI mode mask for \c SPI_Init(). Indicates that the SPI interface should be initialized into slave mode. */
+ #define SPI_MODE_SLAVE (0 << MSTR)
+
+ /** SPI mode mask for \c SPI_Init(). Indicates that the SPI interface should be initialized into master mode. */
+ #define SPI_MODE_MASTER (1 << MSTR)
+ //@}
+
+ /* Inline Functions: */
+ /** Initialises the SPI subsystem, ready for transfers. Must be called before calling any other
+ * SPI routines.
+ *
+ * \param[in] SPIOptions SPI Options, a mask consisting of one of each of the \c SPI_SPEED_*,
+ * \c SPI_SCK_*, \c SPI_SAMPLE_*, \c SPI_ORDER_* and \c SPI_MODE_* masks.
+ */
+ static inline void SPI_Init(const uint8_t SPIOptions)
+ {
+ DDRB |= ((1 << 1) | (1 << 2));
+ DDRB &= ~((1 << 0) | (1 << 3));
+ PORTB |= ((1 << 0) | (1 << 3));
+
+ SPCR = ((1 << SPE) | SPIOptions);
+
+ if (SPIOptions & SPI_USE_DOUBLESPEED)
+ SPSR |= (1 << SPI2X);
+ else
+ SPSR &= ~(1 << SPI2X);
+ }
+
+ /** Turns off the SPI driver, disabling and returning used hardware to their default configuration. */
+ static inline void SPI_Disable(void)
+ {
+ DDRB &= ~((1 << 1) | (1 << 2));
+ PORTB &= ~((1 << 0) | (1 << 3));
+
+ SPCR = 0;
+ SPSR = 0;
+ }
+
+ /** Sends and receives a byte through the SPI interface, blocking until the transfer is complete.
+ *
+ * \param[in] Byte Byte to send through the SPI interface.
+ *
+ * \return Response byte from the attached SPI device.
+ */
+ static inline uint8_t SPI_TransferByte(const uint8_t Byte) ATTR_ALWAYS_INLINE;
+ static inline uint8_t SPI_TransferByte(const uint8_t Byte)
+ {
+ SPDR = Byte;
+ while (!(SPSR & (1 << SPIF)));
+ return SPDR;
+ }
+
+ /** Sends a byte through the SPI interface, blocking until the transfer is complete. The response
+ * byte sent to from the attached SPI device is ignored.
+ *
+ * \param[in] Byte Byte to send through the SPI interface.
+ */
+ static inline void SPI_SendByte(const uint8_t Byte) ATTR_ALWAYS_INLINE;
+ static inline void SPI_SendByte(const uint8_t Byte)
+ {
+ SPDR = Byte;
+ while (!(SPSR & (1 << SPIF)));
+ }
+
+ /** Sends a dummy byte through the SPI interface, blocking until the transfer is complete. The response
+ * byte from the attached SPI device is returned.
+ *
+ * \return The response byte from the attached SPI device.
+ */
+ static inline uint8_t SPI_ReceiveByte(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT;
+ static inline uint8_t SPI_ReceiveByte(void)
+ {
+ SPDR = 0x00;
+ while (!(SPSR & (1 << SPIF)));
+ return SPDR;
+ }
+
+ /* Disable C linkage for C++ Compilers: */
+ #if defined(__cplusplus)
+ }
+ #endif
+
+#endif
+
+/** @} */
+
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