/* LUFA Library Copyright (C) Dean Camera, 2010. dean [at] fourwalledcubicle [dot] com www.fourwalledcubicle.com */ /* Copyright 2010 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 * * SPI driver for the 8-bit AVRs. * * \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 8-Bit AVR SPI Driver * * SPI driver for the 8-bit AVRs. * * \note This file should not be included directly. It is automatically included as needed by the ADC driver * dispatch header located in LUFA/Drivers/Peripheral/SPI.h. * * @{ */ #ifndef __SPI_AVR8_H__ #define __SPI_AVR8_H__ /* Includes: */ #include #include /* Preprocessor Checks: */ #if !defined(__INCLUDE_FROM_SPI_H) #error Do not include this file directly. Include LUFA/Drivers/Peripheral/SPI.h instead. #endif /* Enable C linkage for C++ Compilers: */ #if defined(__cplusplus) extern "C" { #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: */ /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 2. */ #define SPI_SPEED_FCPU_DIV_2 SPI_USE_DOUBLESPEED /** SPI prescaler mask for SPI_Init(). Divides the system clock by a factor of 4. */ #define SPI_SPEED_FCPU_DIV_4 0 /** SPI prescaler mask for 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 SPI_Init(). Divides the system clock by a factor of 16. */ #define SPI_SPEED_FCPU_DIV_16 (1 << SPR0) /** SPI prescaler mask for 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 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 SPI_Init(). Divides the system clock by a factor of 128. */ #define SPI_SPEED_FCPU_DIV_128 ((1 << SPR1) | (1 << SPR0)) /** SPI clock polarity mask for SPI_Init(). Indicates that the SCK should lead on the rising edge. */ #define SPI_SCK_LEAD_RISING (0 << CPOL) /** SPI clock polarity mask for SPI_Init(). Indicates that the SCK should lead on the falling edge. */ #define SPI_SCK_LEAD_FALLING (1 << CPOL) /** SPI data sample mode mask for SPI_Init(). Indicates that the data should sampled on the leading edge. */ #define SPI_SAMPLE_LEADING (0 << CPHA) /** SPI data sample mode mask for SPI_Init(). Indicates that the data should be sampled on the trailing edge. */ #define SPI_SAMPLE_TRAILING (1 << CPHA) /** SPI mode mask for SPI_Init(). Indicates that the SPI interface should be initialized into slave mode. */ #define SPI_MODE_SLAVE (0 << MSTR) /** SPI mode mask for 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 SPI_SPEED_*, * SPI_SCK_*, SPI_SAMPLE_* and SPI_MODE_* masks */ static inline void SPI_Init(const uintN_t SPIOptions) { DDRB |= ((1 << 1) | (1 << 2)); 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_ShutDown(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] Data Byte to send through the SPI interface * * \return Response byte from the attached SPI device */ static inline uint8_t SPI_Transfer(const uint8_t Data) ATTR_ALWAYS_INLINE; static inline uint8_t SPI_Transfer(const uint8_t Data) { SPDR = Data; 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] Data Byte to send through the SPI interface */ static inline void SPI_Send(const uint8_t Data) ATTR_ALWAYS_INLINE; static inline void SPI_Send(const uint8_t Data) { SPDR = Data; 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_Receive(void) ATTR_ALWAYS_INLINE ATTR_WARN_UNUSED_RESULT; static inline uint8_t SPI_Receive(void) { SPDR = 0x00; while (!(SPSR & (1 << SPIF))); return SPDR; } #if defined(__DOXYGEN__) /** Alias for \ref SPI_Transfer(), for compatibility with legacy LUFA applications. */ static inline uint8_t SPI_TransferByte(const uint8_t Byte) ATTR_DEPRECATED; /** Alias for \ref SPI_Send(), for compatibility with legacy LUFA applications. */ static inline void SPI_SendByte(const uint8_t Byte) ATTR_DEPRECATED; /** Alias for \ref SPI_Receive(), for compatibility with legacy LUFA applications. */ static inline uint8_t SPI_ReceiveByte(void) ATTR_DEPRECATED; #else #define SPI_TransferByte(x) SPI_Transfer(x) #define SPI_SendByte(x) SPI_Send(x) #define SPI_ReceiveByte() SPI_Receive() #endif /* Disable C linkage for C++ Compilers: */ #if defined(__cplusplus) } #endif #endif /** @} */