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281 lines
7.2 KiB
C++
281 lines
7.2 KiB
C++
/*
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* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
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* Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API)
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* SPI Master library for arduino.
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*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either the GNU General Public License version 2
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* or the GNU Lesser General Public License version 2.1, both as
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* published by the Free Software Foundation.
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*/
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#include "SPI.h"
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SPIClass::SPIClass(Spi *_spi, uint32_t _id, void(*_initCb)(void)) :
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spi(_spi), id(_id), initCb(_initCb), initialized(false)
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{
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// Empty
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}
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void SPIClass::begin() {
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init();
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// NPCS control is left to the user
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// Default speed set to 4Mhz
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setClockDivider(BOARD_SPI_DEFAULT_SS, 21);
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setDataMode(BOARD_SPI_DEFAULT_SS, SPI_MODE0);
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setBitOrder(BOARD_SPI_DEFAULT_SS, MSBFIRST);
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}
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void SPIClass::begin(uint8_t _pin) {
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init();
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uint32_t spiPin = BOARD_PIN_TO_SPI_PIN(_pin);
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PIO_Configure(
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g_APinDescription[spiPin].pPort,
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g_APinDescription[spiPin].ulPinType,
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g_APinDescription[spiPin].ulPin,
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g_APinDescription[spiPin].ulPinConfiguration);
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// Default speed set to 4Mhz
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setClockDivider(_pin, 21);
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setDataMode(_pin, SPI_MODE0);
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setBitOrder(_pin, MSBFIRST);
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}
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void SPIClass::init() {
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if (initialized)
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return;
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interruptMode = 0;
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interruptSave = 0;
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interruptMask[0] = 0;
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interruptMask[1] = 0;
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interruptMask[2] = 0;
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interruptMask[3] = 0;
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initCb();
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SPI_Configure(spi, id, SPI_MR_MSTR | SPI_MR_PS | SPI_MR_MODFDIS);
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SPI_Enable(spi);
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initialized = true;
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}
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#ifndef interruptsStatus
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#define interruptsStatus() __interruptsStatus()
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static inline unsigned char __interruptsStatus(void) __attribute__((always_inline, unused));
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static inline unsigned char __interruptsStatus(void) {
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unsigned int primask, faultmask;
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asm volatile ("mrs %0, primask" : "=r" (primask));
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if (primask) return 0;
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asm volatile ("mrs %0, faultmask" : "=r" (faultmask));
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if (faultmask) return 0;
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return 1;
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}
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#endif
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void SPIClass::usingInterrupt(uint8_t interruptNumber)
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{
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uint8_t irestore;
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irestore = interruptsStatus();
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noInterrupts();
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if (interruptMode < 16) {
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if (interruptNumber > NUM_DIGITAL_PINS) {
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interruptMode = 16;
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} else {
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Pio *pio = g_APinDescription[interruptNumber].pPort;
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uint32_t mask = g_APinDescription[interruptNumber].ulPin;
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if (pio == PIOA) {
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interruptMode |= 1;
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interruptMask[0] |= mask;
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} else if (pio == PIOB) {
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interruptMode |= 2;
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interruptMask[1] |= mask;
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} else if (pio == PIOC) {
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interruptMode |= 4;
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interruptMask[2] |= mask;
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} else if (pio == PIOD) {
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interruptMode |= 8;
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interruptMask[3] |= mask;
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} else {
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interruptMode = 16;
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}
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}
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}
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if (irestore) interrupts();
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}
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void SPIClass::beginTransaction(uint8_t pin, SPISettings settings)
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{
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uint8_t mode = interruptMode;
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if (mode > 0) {
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if (mode < 16) {
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if (mode & 1) PIOA->PIO_IDR = interruptMask[0];
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if (mode & 2) PIOB->PIO_IDR = interruptMask[1];
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if (mode & 4) PIOC->PIO_IDR = interruptMask[2];
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if (mode & 8) PIOD->PIO_IDR = interruptMask[3];
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} else {
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interruptSave = interruptsStatus();
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noInterrupts();
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}
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}
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uint32_t ch = BOARD_PIN_TO_SPI_CHANNEL(pin);
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bitOrder[ch] = settings.border;
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SPI_ConfigureNPCS(spi, ch, settings.config);
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//setBitOrder(pin, settings.border);
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//setDataMode(pin, settings.datamode);
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//setClockDivider(pin, settings.clockdiv);
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}
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void SPIClass::endTransaction(void)
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{
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uint8_t mode = interruptMode;
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if (mode > 0) {
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if (mode < 16) {
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if (mode & 1) PIOA->PIO_IER = interruptMask[0];
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if (mode & 2) PIOB->PIO_IER = interruptMask[1];
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if (mode & 4) PIOC->PIO_IER = interruptMask[2];
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if (mode & 8) PIOD->PIO_IER = interruptMask[3];
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} else {
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if (interruptSave) interrupts();
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}
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}
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}
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void SPIClass::end(uint8_t _pin) {
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uint32_t spiPin = BOARD_PIN_TO_SPI_PIN(_pin);
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// Setting the pin as INPUT will disconnect it from SPI peripheral
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pinMode(spiPin, INPUT);
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}
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void SPIClass::end() {
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SPI_Disable(spi);
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initialized = false;
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}
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void SPIClass::setBitOrder(uint8_t _pin, BitOrder _bitOrder) {
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uint32_t ch = BOARD_PIN_TO_SPI_CHANNEL(_pin);
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bitOrder[ch] = _bitOrder;
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}
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void SPIClass::setDataMode(uint8_t _pin, uint8_t _mode) {
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uint32_t ch = BOARD_PIN_TO_SPI_CHANNEL(_pin);
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mode[ch] = _mode | SPI_CSR_CSAAT;
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// SPI_CSR_DLYBCT(1) keeps CS enabled for 32 MCLK after a completed
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// transfer. Some device needs that for working properly.
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SPI_ConfigureNPCS(spi, ch, mode[ch] | SPI_CSR_SCBR(divider[ch]) | SPI_CSR_DLYBCT(1));
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}
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void SPIClass::setClockDivider(uint8_t _pin, uint8_t _divider) {
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uint32_t ch = BOARD_PIN_TO_SPI_CHANNEL(_pin);
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divider[ch] = _divider;
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// SPI_CSR_DLYBCT(1) keeps CS enabled for 32 MCLK after a completed
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// transfer. Some device needs that for working properly.
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SPI_ConfigureNPCS(spi, ch, mode[ch] | SPI_CSR_SCBR(divider[ch]) | SPI_CSR_DLYBCT(1));
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}
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byte SPIClass::transfer(byte _pin, uint8_t _data, SPITransferMode _mode) {
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uint32_t ch = BOARD_PIN_TO_SPI_CHANNEL(_pin);
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// Reverse bit order
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if (bitOrder[ch] == LSBFIRST)
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_data = __REV(__RBIT(_data));
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uint32_t d = _data | SPI_PCS(ch);
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if (_mode == SPI_LAST)
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d |= SPI_TDR_LASTXFER;
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// SPI_Write(spi, _channel, _data);
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while ((spi->SPI_SR & SPI_SR_TDRE) == 0)
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;
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spi->SPI_TDR = d;
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// return SPI_Read(spi);
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while ((spi->SPI_SR & SPI_SR_RDRF) == 0)
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;
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d = spi->SPI_RDR;
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// Reverse bit order
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if (bitOrder[ch] == LSBFIRST)
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d = __REV(__RBIT(d));
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return d & 0xFF;
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}
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void SPIClass::transfer(byte _pin, void *_buf, size_t _count, SPITransferMode _mode) {
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if (_count == 0)
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return;
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uint8_t *buffer = (uint8_t *)_buf;
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if (_count == 1) {
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*buffer = transfer(_pin, *buffer, _mode);
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return;
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}
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uint32_t ch = BOARD_PIN_TO_SPI_CHANNEL(_pin);
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bool reverse = (bitOrder[ch] == LSBFIRST);
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// Send the first byte
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uint32_t d = *buffer;
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if (reverse)
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d = __REV(__RBIT(d));
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while ((spi->SPI_SR & SPI_SR_TDRE) == 0)
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;
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spi->SPI_TDR = d | SPI_PCS(ch);
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while (_count > 1) {
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// Prepare next byte
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d = *(buffer+1);
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if (reverse)
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d = __REV(__RBIT(d));
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if (_count == 2 && _mode == SPI_LAST)
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d |= SPI_TDR_LASTXFER;
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// Read transferred byte and send next one straight away
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while ((spi->SPI_SR & SPI_SR_RDRF) == 0)
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;
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uint8_t r = spi->SPI_RDR;
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spi->SPI_TDR = d | SPI_PCS(ch);
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// Save read byte
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if (reverse)
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r = __REV(__RBIT(r));
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*buffer = r;
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buffer++;
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_count--;
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}
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// Receive the last transferred byte
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while ((spi->SPI_SR & SPI_SR_RDRF) == 0)
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;
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uint8_t r = spi->SPI_RDR;
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if (reverse)
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r = __REV(__RBIT(r));
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*buffer = r;
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}
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void SPIClass::attachInterrupt(void) {
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// Should be enableInterrupt()
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}
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void SPIClass::detachInterrupt(void) {
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// Should be disableInterrupt()
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}
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#if SPI_INTERFACES_COUNT > 0
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static void SPI_0_Init(void) {
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PIO_Configure(
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g_APinDescription[PIN_SPI_MOSI].pPort,
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g_APinDescription[PIN_SPI_MOSI].ulPinType,
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g_APinDescription[PIN_SPI_MOSI].ulPin,
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g_APinDescription[PIN_SPI_MOSI].ulPinConfiguration);
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PIO_Configure(
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g_APinDescription[PIN_SPI_MISO].pPort,
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g_APinDescription[PIN_SPI_MISO].ulPinType,
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g_APinDescription[PIN_SPI_MISO].ulPin,
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g_APinDescription[PIN_SPI_MISO].ulPinConfiguration);
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PIO_Configure(
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g_APinDescription[PIN_SPI_SCK].pPort,
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g_APinDescription[PIN_SPI_SCK].ulPinType,
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g_APinDescription[PIN_SPI_SCK].ulPin,
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g_APinDescription[PIN_SPI_SCK].ulPinConfiguration);
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}
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SPIClass SPI(SPI_INTERFACE, SPI_INTERFACE_ID, SPI_0_Init);
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#endif
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