mirror of https://github.com/ArduPilot/ardupilot
192 lines
6.9 KiB
C
192 lines
6.9 KiB
C
/*
|
|
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
|
|
* \brief Master include file for the SPI peripheral driver.
|
|
*
|
|
* Hardware SPI subsystem driver for the supported USB AVRs models.
|
|
*/
|
|
|
|
/** \ingroup Group_PeripheralDrivers
|
|
* @defgroup Group_SPI SPI Driver - LUFA/Drivers/Peripheral/SPI.h
|
|
*
|
|
* \section Sec_Dependencies Module Source Dependencies
|
|
* The following files must be built with any user project that uses this module:
|
|
* - None
|
|
*
|
|
* \section Module Description
|
|
* Driver for the hardware SPI port available on most AVR models. This module provides
|
|
* an easy to use driver for the setup of and transfer of data over the AVR's SPI port.
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
#ifndef __SPI_H__
|
|
#define __SPI_H__
|
|
|
|
/* Includes: */
|
|
#include <stdbool.h>
|
|
|
|
/* 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 data order mask for SPI_Init(). Indicates that data should be shifted out MSB first. */
|
|
#define SPI_ORDER_MSB_FIRST (0 << DORD)
|
|
|
|
/** SPI data order mask for SPI_Init(). Indicates that data should be shifted out MSB first. */
|
|
#define SPI_ORDER_LSB_FIRST (1 << DORD)
|
|
|
|
/** 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_*, SPI_ORDER_* and SPI_MODE_* masks.
|
|
*/
|
|
static inline void SPI_Init(const uint8_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] 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
|
|
|
|
/** @} */
|