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Code Issues Releases Activity

[avr] Made SPI.begin() and SPI.end() synchronized (Andrew Kroll)

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This commit is contained in:
Cristian Maglie 2014-10-21 12:57:41 +02:00
parent 53e25d8b55
commit 8344812ce8
2 changed files with 43 additions and 20 deletions
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21
hardware/arduino/avr/libraries/SPI/SPI.cpp
View File

@ -2,6 +2,7 @@
* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st> * Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
* Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API) * Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API)
* Copyright (c) 2014 by Matthijs Kooijman <matthijs@stdin.nl> (SPISettings AVR) * Copyright (c) 2014 by Matthijs Kooijman <matthijs@stdin.nl> (SPISettings AVR)
* Copyright (c) 2014 by Andrew J. Kroll <xxxajk@gmail.com> (atomicity fixes)
* SPI Master library for arduino. * SPI Master library for arduino.
* *
* This file is free software; you can redistribute it and/or modify * This file is free software; you can redistribute it and/or modify
@ -14,6 +15,7 @@
SPIClass SPI; SPIClass SPI;
uint8_t SPIClass::initialized = 0;
uint8_t SPIClass::interruptMode = 0; uint8_t SPIClass::interruptMode = 0;
uint8_t SPIClass::interruptMask = 0; uint8_t SPIClass::interruptMask = 0;
uint8_t SPIClass::interruptSave = 0; uint8_t SPIClass::interruptSave = 0;
@ -23,6 +25,9 @@ uint8_t SPIClass::inTransactionFlag = 0;
void SPIClass::begin() 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 // Set SS to high so a connected chip will be "deselected" by default
digitalWrite(SS, HIGH); digitalWrite(SS, HIGH);
@ -46,9 +51,25 @@ void SPIClass::begin()
pinMode(SCK, OUTPUT); pinMode(SCK, OUTPUT);
pinMode(MOSI, OUTPUT); pinMode(MOSI, OUTPUT);
} }
initialized++; // reference count
SREG = sreg;
}
void SPIClass::end() { 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); 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 // mapping of interrupt numbers to bits within SPI_AVR_EIMSK

2
hardware/arduino/avr/libraries/SPI/SPI.h
View File

@ -2,6 +2,7 @@
* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st> * Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
* Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API) * Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API)
* Copyright (c) 2014 by Matthijs Kooijman <matthijs@stdin.nl> (SPISettings AVR) * Copyright (c) 2014 by Matthijs Kooijman <matthijs@stdin.nl> (SPISettings AVR)
* Copyright (c) 2014 by Andrew J. Kroll <xxxajk@gmail.com> (atomicity fixes)
* SPI Master library for arduino. * SPI Master library for arduino.
* *
* This file is free software; you can redistribute it and/or modify * This file is free software; you can redistribute it and/or modify
@ -281,6 +282,7 @@ public:
inline static void detachInterrupt() { SPCR &= ~_BV(SPIE); } inline static void detachInterrupt() { SPCR &= ~_BV(SPIE); }
private: private:
static uint8_t initialized;
static uint8_t interruptMode; // 0=none, 1=mask, 2=global static uint8_t interruptMode; // 0=none, 1=mask, 2=global
static uint8_t interruptMask; // which interrupts to mask static uint8_t interruptMask; // which interrupts to mask
static uint8_t interruptSave; // temp storage, to restore state static uint8_t interruptSave; // temp storage, to restore state