From cb722cfd0699b157ba5bcc1f333fb7e5313065a5 Mon Sep 17 00:00:00 2001
From: Claudio Indellicati <c.indellicati@arduino.cc>
Date: Fri, 27 Mar 2015 13:13:47 +0100
Subject: [PATCH] Implemented SPI Transaction API.
---
libraries/SPI/SPI.cpp | 93 +++++++++++++++++++++++++++++++++++++------
libraries/SPI/SPI.h | 55 ++++++++++++++++++-------
2 files changed, 121 insertions(+), 27 deletions(-)
diff --git a/libraries/SPI/SPI.cpp b/libraries/SPI/SPI.cpp
index 18a7c853..c3252cab 100644
--- a/libraries/SPI/SPI.cpp
+++ b/libraries/SPI/SPI.cpp
@@ -1,6 +1,6 @@
/*
- * SPI Master library for arduino.
- * Copyright (c) 2014 Arduino.
+ * SPI Master library for Arduino.
+ * Copyright (c) 2015 Arduino LLC
*
* 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
@@ -13,8 +13,15 @@
#include "assert.h"
#include "variant.h"
+#define SPI_IMODE_NONE 0
+#define SPI_IMODE_EXTINT 1
+#define SPI_IMODE_GLOBAL 2
+
+const SPISettings DEFAULT_SPI_SETTINGS = SPISettings();
+
SPIClass::SPIClass(SERCOM *p_sercom, uint8_t uc_pinMISO, uint8_t uc_pinSCK, uint8_t uc_pinMOSI)
{
+ initialized = false;
assert(p_sercom != NULL);
_p_sercom = p_sercom;
@@ -25,14 +32,32 @@ SPIClass::SPIClass(SERCOM *p_sercom, uint8_t uc_pinMISO, uint8_t uc_pinSCK, uint
void SPIClass::begin()
{
+ init();
+
// PIO init
pinPeripheral(_uc_pinMiso, g_APinDescription[_uc_pinMiso].ulPinType);
pinPeripheral(_uc_pinSCK, g_APinDescription[_uc_pinSCK].ulPinType);
pinPeripheral(_uc_pinMosi, g_APinDescription[_uc_pinMosi].ulPinType);
- // Default speed set to 4Mhz, SPI mode set to MODE 0 and Bit order set to MSB first.
- _p_sercom->initSPI(SPI_PAD_2_SCK_3, SERCOM_RX_PAD_0, SPI_CHAR_SIZE_8_BITS, MSB_FIRST);
- _p_sercom->initSPIClock(SERCOM_SPI_MODE_0, 4000000);
+ config(DEFAULT_SPI_SETTINGS);
+}
+
+void SPIClass::init()
+{
+ if (initialized)
+ return;
+ interruptMode = SPI_IMODE_NONE;
+ interruptSave = 0;
+ interruptMask = 0;
+ initialized = true;
+}
+
+void SPIClass::config(SPISettings settings)
+{
+ _p_sercom->disableSPI();
+
+ _p_sercom->initSPI(SPI_PAD_2_SCK_3, SERCOM_RX_PAD_0, SPI_CHAR_SIZE_8_BITS, settings.bitOrder);
+ _p_sercom->initSPIClock(settings.dataMode, settings.clockFreq);
_p_sercom->enableSPI();
}
@@ -40,25 +65,67 @@ void SPIClass::begin()
void SPIClass::end()
{
_p_sercom->resetSPI();
+ initialized = false;
}
+#ifndef interruptsStatus
+#define interruptsStatus() __interruptsStatus()
+static inline unsigned char __interruptsStatus(void) __attribute__((always_inline, unused));
+static inline unsigned char __interruptsStatus(void)
+{
+ // See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0497a/CHDBIBGJ.html
+ return (__get_PRIMASK() ? 0 : 1);
+}
+#endif
-void SPIClass::usingInterrupt(uint8_t interruptNumber)
+void SPIClass::usingInterrupt(int interruptNumber)
{
- // XXX: TODO
+ if ((interruptNumber == NOT_AN_INTERRUPT) || (interruptNumber == EXTERNAL_INT_NMI))
+ return;
+
+ uint8_t irestore = interruptsStatus();
+ noInterrupts();
+
+ if (interruptNumber >= EXTERNAL_NUM_INTERRUPTS)
+ interruptMode = SPI_IMODE_GLOBAL;
+ else
+ {
+ interruptMode |= SPI_IMODE_EXTINT;
+ interruptMask |= (1 << interruptNumber);
+ }
+
+ if (irestore)
+ interrupts();
}
void SPIClass::beginTransaction(SPISettings settings)
{
- // XXX: TODO
- setBitOrder(settings.bitOrder);
- setClockDivider(settings.clockDiv);
- setDataMode(settings.dataMode);
+ if (interruptMode != SPI_IMODE_NONE)
+ {
+ if (interruptMode & SPI_IMODE_GLOBAL)
+ {
+ interruptSave = interruptsStatus();
+ noInterrupts();
+ }
+ else if (interruptMode & SPI_IMODE_EXTINT)
+ EIC->INTENCLR.reg = EIC_INTENCLR_EXTINT(interruptMask);
+ }
+
+ config(settings);
}
void SPIClass::endTransaction(void)
{
- // XXX: TODO
+ if (interruptMode != SPI_IMODE_NONE)
+ {
+ if (interruptMode & SPI_IMODE_GLOBAL)
+ {
+ if (interruptSave)
+ interrupts();
+ }
+ else if (interruptMode & SPI_IMODE_EXTINT)
+ EIC->INTENSET.reg = EIC_INTENSET_EXTINT(interruptMask);
+ }
}
void SPIClass::setBitOrder(BitOrder order)
@@ -110,7 +177,7 @@ byte SPIClass::transfer(uint8_t data)
_p_sercom->writeDataSPI(data);
// Read data
- return _p_sercom->readDataSPI();
+ return _p_sercom->readDataSPI() & 0xFF;
}
void SPIClass::attachInterrupt() {
diff --git a/libraries/SPI/SPI.h b/libraries/SPI/SPI.h
index 65a825ad..bedaf9e4 100644
--- a/libraries/SPI/SPI.h
+++ b/libraries/SPI/SPI.h
@@ -1,6 +1,7 @@
/*
+ * SPI Master library for Arduino.
* Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
- * SPI Master library for arduino.
+ * Copyright (c) 2015 Arduino LLC
*
* 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
@@ -13,6 +14,13 @@
#include <Arduino.h>
+// SPI_HAS_TRANSACTION means SPI has
+// - beginTransaction()
+// - endTransaction()
+// - usingInterrupt()
+// - SPISetting(clock, bitOrder, dataMode)
+#define SPI_HAS_TRANSACTION 1
+
#define SPI_MODE0 0x02
#define SPI_MODE1 0x00
#define SPI_MODE2 0x03
@@ -38,6 +46,7 @@ class SPISettings {
}
}
+ // 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); }
private:
@@ -46,21 +55,32 @@ class SPISettings {
}
void init_AlwaysInline(uint32_t clock, BitOrder bitOrder, uint8_t dataMode) __attribute__((__always_inline__)) {
- uint8_t div;
- if (clock < (F_CPU / 255)) {
- div = 255;
- } else if (clock >= (F_CPU / SPI_MIN_CLOCK_DIVIDER)) {
- div = SPI_MIN_CLOCK_DIVIDER;
- } else {
- div = (F_CPU / (clock + 1)) + 1;
+ this->clockFreq = (clock >= (F_CPU / SPI_MIN_CLOCK_DIVIDER) ? F_CPU / SPI_MIN_CLOCK_DIVIDER : clock);
+
+ this->bitOrder = (bitOrder == MSBFIRST ? MSB_FIRST : LSB_FIRST);
+
+ switch (dataMode)
+ {
+ case SPI_MODE0:
+ this->dataMode = SERCOM_SPI_MODE_0;
+
+ case SPI_MODE1:
+ this->dataMode = SERCOM_SPI_MODE_1;
+
+ case SPI_MODE2:
+ this->dataMode = SERCOM_SPI_MODE_2;
+
+ case SPI_MODE3:
+ this->dataMode = SERCOM_SPI_MODE_3;
+
+ default:
+ this->dataMode = SERCOM_SPI_MODE_0;
}
- this->clockDiv = div;
- this->dataMode = dataMode;
- this->bitOrder = bitOrder;
}
- uint8_t clockDiv, dataMode;
- BitOrder bitOrder;
+ uint32_t clockFreq;
+ SercomSpiClockMode dataMode;
+ SercomDataOrder bitOrder;
friend class SPIClass;
};
@@ -73,7 +93,7 @@ class SPIClass {
inline void transfer(void *buf, size_t count);
// Transaction Functions
- void usingInterrupt(uint8_t interruptNumber);
+ void usingInterrupt(int interruptNumber);
void beginTransaction(SPISettings settings);
void endTransaction(void);
@@ -89,10 +109,17 @@ class SPIClass {
void setClockDivider(uint8_t uc_div);
private:
+ void init();
+ void config(SPISettings settings);
+
SERCOM *_p_sercom;
uint8_t _uc_pinMiso;
uint8_t _uc_pinMosi;
uint8_t _uc_pinSCK;
+ bool initialized;
+ uint8_t interruptMode;
+ char interruptSave;
+ uint32_t interruptMask;
};
void SPIClass::transfer(void *buf, size_t count)
--
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