From 3ba80468d56485f9a078dbd0854b80beaacbcbd4 Mon Sep 17 00:00:00 2001 From: Alice Pintus Date: Wed, 2 Mar 2016 14:45:57 +0100 Subject: add src folder when missing --- libraries/SPI/src/SPI.cpp | 201 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) create mode 100644 libraries/SPI/src/SPI.cpp (limited to 'libraries/SPI/src/SPI.cpp') diff --git a/libraries/SPI/src/SPI.cpp b/libraries/SPI/src/SPI.cpp new file mode 100644 index 0000000..af14e07 --- /dev/null +++ b/libraries/SPI/src/SPI.cpp @@ -0,0 +1,201 @@ +/* + * Copyright (c) 2010 by Cristian Maglie + * Copyright (c) 2014 by Paul Stoffregen (Transaction API) + * Copyright (c) 2014 by Matthijs Kooijman (SPISettings AVR) + * Copyright (c) 2014 by Andrew J. Kroll (atomicity fixes) + * SPI Master library for arduino. + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of either the GNU General Public License version 2 + * or the GNU Lesser General Public License version 2.1, both as + * published by the Free Software Foundation. + */ + +#include "SPI.h" + +SPIClass SPI; + +uint8_t SPIClass::initialized = 0; +uint8_t SPIClass::interruptMode = 0; +uint8_t SPIClass::interruptMask = 0; +uint8_t SPIClass::interruptSave = 0; +#ifdef SPI_TRANSACTION_MISMATCH_LED +uint8_t SPIClass::inTransactionFlag = 0; +#endif + +void SPIClass::begin() +{ + uint8_t sreg = SREG; + noInterrupts(); // Protect from a scheduler and prevent transactionBegin + if (!initialized) { + // Set SS to high so a connected chip will be "deselected" by default + uint8_t port = digitalPinToPort(SS); + uint8_t bit = digitalPinToBitMask(SS); + volatile uint8_t *reg = portModeRegister(port); + + // if the SS pin is not already configured as an output + // then set it high (to enable the internal pull-up resistor) + if(!(*reg & bit)){ + digitalWrite(SS, HIGH); + } + + // When the SS pin is set as OUTPUT, it can be used as + // a general purpose output port (it doesn't influence + // SPI operations). + pinMode(SS, OUTPUT); + + // Warning: if the SS pin ever becomes a LOW INPUT then SPI + // automatically switches to Slave, so the data direction of + // the SS pin MUST be kept as OUTPUT. + SPCR |= _BV(MSTR); + SPCR |= _BV(SPE); + + // Set direction register for SCK and MOSI pin. + // MISO pin automatically overrides to INPUT. + // By doing this AFTER enabling SPI, we avoid accidentally + // clocking in a single bit since the lines go directly + // from "input" to SPI control. + // http://code.google.com/p/arduino/issues/detail?id=888 + pinMode(SCK, OUTPUT); + pinMode(MOSI, OUTPUT); + } + initialized++; // reference count + SREG = sreg; +} + +void SPIClass::end() { + uint8_t sreg = SREG; + noInterrupts(); // Protect from a scheduler and prevent transactionBegin + // Decrease the reference counter + if (initialized) + initialized--; + // If there are no more references disable SPI + if (!initialized) { + SPCR &= ~_BV(SPE); + interruptMode = 0; + #ifdef SPI_TRANSACTION_MISMATCH_LED + inTransactionFlag = 0; + #endif + } + SREG = sreg; +} + +// mapping of interrupt numbers to bits within SPI_AVR_EIMSK +#if defined(__AVR_ATmega32U4__) + #define SPI_INT0_MASK (1<