HardwareSPI.h

/*
 HardwareSPI.h - Hardware SPI interface for Arduino
 Copyright (c) 2018 Arduino LLC. All right reserved.

 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/

#pragma once

#include"Common.h"
#include<inttypes.h>
#include"Stream.h"

#defineSPI_HAS_TRANSACTION

namespacearduino {

typedefenum {
 SPI_MODE0 = 0,
 SPI_MODE1 = 1,
 SPI_MODE2 = 2,
 SPI_MODE3 = 3,
} SPIMode;


classSPISettings {
public:
SPISettings(uint32_t clock, BitOrder bitOrder, SPIMode dataMode) {
if (__builtin_constant_p(clock)) {
init_AlwaysInline(clock, bitOrder, dataMode);
 } else {
init_MightInline(clock, bitOrder, dataMode);
 }
 }

SPISettings(uint32_t clock, BitOrder bitOrder, int dataMode) {
if (__builtin_constant_p(clock)) {
init_AlwaysInline(clock, bitOrder, (SPIMode)dataMode);
 } else {
init_MightInline(clock, bitOrder, (SPIMode)dataMode);
 }
 }

// Default speed set to 4MHz, SPI mode set to MODE 0 and Bit order set to MSB first.
SPISettings() { init_AlwaysInline(4000000, MSBFIRST, SPI_MODE0); }

booloperator==(const SPISettings& rhs) const
 {
if ((this->clockFreq == rhs.clockFreq) &&
 (this->bitOrder == rhs.bitOrder) &&
 (this->dataMode == rhs.dataMode)) {
returntrue;
 }
returnfalse;
 }

booloperator!=(const SPISettings& rhs) const
 {
return !(*this == rhs);
 }

uint32_tgetClockFreq() const {
return clockFreq;
 }
 SPIMode getDataMode() const {
return dataMode;
 }
 BitOrder getBitOrder() const {
return (bitOrder);
 }

private:
voidinit_MightInline(uint32_t clock, BitOrder bitOrder, SPIMode dataMode) {
init_AlwaysInline(clock, bitOrder, dataMode);
 }

// Core developer MUST use an helper function in beginTransaction() to use this data
voidinit_AlwaysInline(uint32_t clock, BitOrder bitOrder, SPIMode dataMode) __attribute__((__always_inline__)) {
this->clockFreq = clock;
this->dataMode = dataMode;
this->bitOrder = bitOrder;
 }

uint32_t clockFreq;
 SPIMode dataMode;
 BitOrder bitOrder;

friendclassHardwareSPI;
};

const SPISettings DEFAULT_SPI_SETTINGS = SPISettings();

classHardwareSPI
{
public:
virtual~HardwareSPI() { }

virtualuint8_ttransfer(uint8_t data) = 0;
virtualuint16_ttransfer16(uint16_t data) = 0;
virtualvoidtransfer(void *buf, size_t count) = 0;

// Transaction Functions
virtualvoidusingInterrupt(int interruptNumber) = 0;
virtualvoidnotUsingInterrupt(int interruptNumber) = 0;
virtualvoidbeginTransaction(SPISettings settings) = 0;
virtualvoidendTransaction(void) = 0;

// SPI Configuration methods
virtualvoidattachInterrupt() = 0;
virtualvoiddetachInterrupt() = 0;

virtualvoidbegin() = 0;
virtualvoidend() = 0;
};

// Alias SPIClass to HardwareSPI since it's already the defacto standard for SPI class name
typedef HardwareSPI SPIClass;

}