From 9a5be09f06d4613a0e49110b2d491759a1b620b9 Mon Sep 17 00:00:00 2001
From: Cristian Maglie <c.maglie@bug.st>
Date: Fri, 18 May 2012 01:30:54 +0200
Subject: [PATCH] [sam] Refactoring API for SPI library

---
 hardware/arduino/sam/libraries/SPI/SPI.cpp    | 75 ++++++++-----------
 hardware/arduino/sam/libraries/SPI/SPI.h      | 23 +++---
 .../DueX_ATFlashSignatureCheck.ino            | 48 ++++++------
 .../arduino/sam/libraries/SPI/keywords.txt    | 16 ++--
 .../sam/variants/arduino_due_x/variant.h      |  1 +
 5 files changed, 77 insertions(+), 86 deletions(-)

diff --git a/hardware/arduino/sam/libraries/SPI/SPI.cpp b/hardware/arduino/sam/libraries/SPI/SPI.cpp
index 4c61f2cf2..277aee37c 100644
--- a/hardware/arduino/sam/libraries/SPI/SPI.cpp
+++ b/hardware/arduino/sam/libraries/SPI/SPI.cpp
@@ -10,75 +10,71 @@
 
 #include "SPI.h"
 
-SPIClass::SPIClass(Spi *_spi, uint32_t _id, void(*_initCb)(void), uint32_t *_ss) :
+SPIClass::SPIClass(Spi *_spi, uint32_t _id, void(*_initCb)(void)) :
 	spi(_spi), id(_id), initCb(_initCb)
 {
-	for (int i=0; i<SPI_CHANNELS_NUM; i++)
-		ssPins[i] = _ss[i];
-}
-
-void SPIClass::begin() {
 	initCb();
 
-	// Set CS on NPCS3
 	SPI_Configure(spi, id, SPI_MR_MSTR | SPI_MR_PS);
 	SPI_Enable(spi);
 	setClockDivider(1);
 	setDataMode(SPI_MODE0);
 }
 
-void SPIClass::addSlave(uint8_t _channel) {
-	uint32_t pin = ssPins[_channel];
-	if (pin == 0)
+void SPIClass::begin(uint8_t _pin) {
+	if (_pin == 0)
 		return;
-	PIO_Configure(g_APinDescription[pin].pPort,
-		g_APinDescription[pin].ulPinType,
-		g_APinDescription[pin].ulPin,
-		g_APinDescription[pin].ulPinConfiguration);
+	PIO_Configure(g_APinDescription[_pin].pPort,
+		g_APinDescription[_pin].ulPinType,
+		g_APinDescription[_pin].ulPin,
+		g_APinDescription[_pin].ulPinConfiguration);
 }
 
 void SPIClass::end() {
 	SPI_Disable(spi);
 }
 
-void SPIClass::setBitOrder(uint8_t bitOrder) {
-	setBitOrder(bitOrder, 0);
-	setBitOrder(bitOrder, 1);
-	setBitOrder(bitOrder, 2);
-	setBitOrder(bitOrder, 3);
-}
+//void SPIClass::setBitOrder(uint8_t bitOrder) {
+//	setBitOrder(bitOrder, 0);
+//	setBitOrder(bitOrder, 1);
+//	setBitOrder(bitOrder, 2);
+//	setBitOrder(bitOrder, 3);
+//}
 
-void SPIClass::setBitOrder(uint8_t bitOrder, uint8_t _channel) {
-	// Not supported
-}
+//void SPIClass::setBitOrder(uint8_t bitOrder, uint8_t _channel) {
+//	// Not supported
+//}
 
 void SPIClass::setDataMode(uint8_t _mode) {
-	setDataMode(_mode, 0);
-	setDataMode(_mode, 1);
-	setDataMode(_mode, 2);
-	setDataMode(_mode, 3);
+	setDataMode(PIN_SPI_SS0, _mode);
+	setDataMode(PIN_SPI_SS1, _mode);
+	setDataMode(PIN_SPI_SS2, _mode);
+	setDataMode(PIN_SPI_SS3, _mode);
 }
 
-void SPIClass::setDataMode(uint8_t _mode, uint8_t _channel) {
+void SPIClass::setDataMode(uint8_t _pin, uint8_t _mode) {
+	uint32_t _channel = SPI_PIN_TO_SPI_CHANNEL(_pin);
 	mode[_channel] = _mode | SPI_CSR_CSAAT;
 	SPI_ConfigureNPCS(spi, _channel, mode[_channel] | SPI_CSR_SCBR(divider[_channel]));
 }
 
 void SPIClass::setClockDivider(uint8_t _divider) {
-	setClockDivider(_divider, 0);
-	setClockDivider(_divider, 1);
-	setClockDivider(_divider, 2);
-	setClockDivider(_divider, 3);
+	setClockDivider(PIN_SPI_SS0, _divider);
+	setClockDivider(PIN_SPI_SS1, _divider);
+	setClockDivider(PIN_SPI_SS2, _divider);
+	setClockDivider(PIN_SPI_SS3, _divider);
 }
 
-void SPIClass::setClockDivider(uint8_t _divider, uint8_t _channel) {
+void SPIClass::setClockDivider(uint8_t _pin, uint8_t _divider) {
+	uint32_t _channel = SPI_PIN_TO_SPI_CHANNEL(_pin);
 	divider[_channel] = _divider;
 	SPI_ConfigureNPCS(spi, _channel, mode[_channel] | SPI_CSR_SCBR(divider[_channel]));
 }
 
-byte SPIClass::transfer(byte _data, uint8_t _channel, bool _last) {
+byte SPIClass::transfer(byte _pin, uint8_t _data, SPITransferMode _mode) {
+	uint32_t _channel = SPI_PIN_TO_SPI_CHANNEL(_pin);
 	uint32_t d = _data | SPI_PCS(_channel);
-	if (_last)
+	if (_mode == SPI_LAST)
 		d |= SPI_TDR_LASTXFER;
 
 	// SPI_Write(spi, _channel, _data);
@@ -117,12 +113,5 @@ static void SPI_0_Init(void) {
 			g_APinDescription[PIN_SPI_SCK].ulPinConfiguration);
 }
 
-uint32_t SPI_0_SS[] = {
-	PIN_SPI_SS0,
-	PIN_SPI_SS1,
-	PIN_SPI_SS2,
-	PIN_SPI_SS3
-};
-
-SPIClass SPI_0(SPI_INTERFACE, SPI_INTERFACE_ID, SPI_0_Init, SPI_0_SS);
+SPIClass SPI(SPI_INTERFACE, SPI_INTERFACE_ID, SPI_0_Init);
 #endif
diff --git a/hardware/arduino/sam/libraries/SPI/SPI.h b/hardware/arduino/sam/libraries/SPI/SPI.h
index 7408813f6..5d4c0e260 100644
--- a/hardware/arduino/sam/libraries/SPI/SPI.h
+++ b/hardware/arduino/sam/libraries/SPI/SPI.h
@@ -19,42 +19,45 @@
 #define SPI_MODE2 0x03
 #define SPI_MODE3 0x01
 
+enum SPITransferMode {
+	SPI_CONTINUE,
+	SPI_LAST
+};
+
 class SPIClass {
   public:
-	SPIClass(Spi *_spi, uint32_t _id, void(*_initCb)(void), uint32_t *_ss);
+	SPIClass(Spi *_spi, uint32_t _id, void(*_initCb)(void));
 
-	byte transfer(byte _data, uint8_t _channel = 0, bool _last = true);
+	byte transfer(byte _channel, uint8_t _data, SPITransferMode _mode = SPI_LAST);
 
 	// SPI Configuration methods
 
 	void attachInterrupt(void);
 	void detachInterrupt(void);
 
-	void begin(void);
-	void addSlave(uint8_t _channel);
+	void begin(uint8_t _channel);
 	void end(void);
 
 	// These methods sets the same parameters on all channels
-	void setBitOrder(uint8_t);
+	//void setBitOrder(uint8_t);
 	void setDataMode(uint8_t);
 	void setClockDivider(uint8_t);
 
 	// These methods sets a parameter on a single channel
-	void setBitOrder(uint8_t, uint8_t _channel);
-	void setDataMode(uint8_t, uint8_t _channel);
-	void setClockDivider(uint8_t, uint8_t _channel);
+	// void setBitOrder(uint8_t _channel, uint8_t);
+	void setDataMode(uint8_t _channel, uint8_t);
+	void setClockDivider(uint8_t _channel, uint8_t);
 
   private:
 	Spi *spi;
 	uint32_t id;
 	uint32_t divider[SPI_CHANNELS_NUM];
 	uint32_t mode[SPI_CHANNELS_NUM];
-	uint32_t ssPins[SPI_CHANNELS_NUM];
 	void (*initCb)(void);
 };
 
 #if SPI_INTERFACES_COUNT > 0
-extern SPIClass SPI_0;
+extern SPIClass SPI;
 #endif
 
 #endif
diff --git a/hardware/arduino/sam/libraries/SPI/examples/DueX_ATFlashSignatureCheck/DueX_ATFlashSignatureCheck.ino b/hardware/arduino/sam/libraries/SPI/examples/DueX_ATFlashSignatureCheck/DueX_ATFlashSignatureCheck.ino
index 4613abfd7..009369bc7 100644
--- a/hardware/arduino/sam/libraries/SPI/examples/DueX_ATFlashSignatureCheck/DueX_ATFlashSignatureCheck.ino
+++ b/hardware/arduino/sam/libraries/SPI/examples/DueX_ATFlashSignatureCheck/DueX_ATFlashSignatureCheck.ino
@@ -1,38 +1,34 @@
 
 #include <SPI.h>
 
-#define FLASH_SPI_CHAN 3
+// Flash memory is connected on SPI pin SS3
+#define FLASH PIN_SPI_SS3
 
 void setup() {
-  Serial1.begin(9600);
-  SPI_0.begin();
-  SPI_0.addSlave(FLASH_SPI_CHAN);
-  SPI_0.setClockDivider(2); // We are too fast with 1
+  Serial.begin(9600);
+  SPI.begin(FLASH);
+  SPI.setClockDivider(2); // We are too fast with 1
 }
 
 void loop() {
-  Serial1.println("Sending 'Identify' cmd to flash => 9F");
+  Serial.println("Sending 'Identify' cmd to flash => 9F");
   
-  // Send cmd and receive response on the same transaction
-  // Parameter "false" keeps the SS pin active
-  SPI_0.transfer(0x9f, FLASH_SPI_CHAN, false);
-  char a1 = SPI_0.transfer(0x00, FLASH_SPI_CHAN, false);
-  char a2 = SPI_0.transfer(0x00, FLASH_SPI_CHAN, false);
-  char a3 = SPI_0.transfer(0x00, FLASH_SPI_CHAN, false);
-  char a4 = SPI_0.transfer(0x00, FLASH_SPI_CHAN, false);
-  char a5 = SPI_0.transfer(0x00, FLASH_SPI_CHAN);
+  // Send "identify" command (9f) and receive response 
+  // on the same SPI transaction. Parameter SPI_CONTINUE 
+  // keeps the SS pin active.
+  SPI.transfer(FLASH, 0x9f, SPI_CONTINUE);
+  char a1 = SPI.transfer(FLASH, 0x00, SPI_CONTINUE);
+  char a2 = SPI.transfer(FLASH, 0x00, SPI_CONTINUE);
+  char a3 = SPI.transfer(FLASH, 0x00, SPI_CONTINUE);
+  char a4 = SPI.transfer(FLASH, 0x00, SPI_CONTINUE);
+  char a5 = SPI.transfer(FLASH, 0x00);
 
-  Serial1.print("Received signature: ");
-  Serial1.print(a1, HEX);
-  Serial1.print(" ");
-  Serial1.print(a2, HEX);
-  Serial1.print(" ");
-  Serial1.print(a3, HEX);
-  Serial1.print(" ");
-  Serial1.print(a4, HEX);
-  Serial1.print(" ");
-  Serial1.print(a5, HEX);
-  Serial1.println();
+  // Print response over serial port
+  Serial.print("Received signature: ");
+  Serial.print(a1, HEX);
+  Serial.print(a2, HEX);
+  Serial.print(a3, HEX);
+  Serial.print(a4, HEX);
+  Serial.println(a5, HEX);
   delay(1000);
 }
-
diff --git a/hardware/arduino/sam/libraries/SPI/keywords.txt b/hardware/arduino/sam/libraries/SPI/keywords.txt
index 326b698da..47738f9fa 100644
--- a/hardware/arduino/sam/libraries/SPI/keywords.txt
+++ b/hardware/arduino/sam/libraries/SPI/keywords.txt
@@ -6,16 +6,15 @@
 # Datatypes (KEYWORD1)
 #######################################
 
-SPI_0	KEYWORD1
+SPI	KEYWORD1
 
 #######################################
 # Methods and Functions (KEYWORD2)
 #######################################
 begin			KEYWORD2
-addSlave		KEYWORD2
 end				KEYWORD2
 transfer		KEYWORD2
-setBitOrder		KEYWORD2
+#setBitOrder	KEYWORD2
 setDataMode		KEYWORD2
 setClockDivider	KEYWORD2
 
@@ -23,7 +22,10 @@ setClockDivider	KEYWORD2
 #######################################
 # Constants (LITERAL1)
 #######################################
-SPI_MODE0	LITERAL1
-SPI_MODE1	LITERAL1
-SPI_MODE2	LITERAL1
-SPI_MODE3	LITERAL1
\ No newline at end of file
+SPI_MODE0		LITERAL1
+SPI_MODE1		LITERAL1
+SPI_MODE2		LITERAL1
+SPI_MODE3		LITERAL1
+
+SPI_CONTINUE	LITERAL1
+SPI_LAST		LITERAL1
diff --git a/hardware/arduino/sam/variants/arduino_due_x/variant.h b/hardware/arduino/sam/variants/arduino_due_x/variant.h
index 6f11f1aab..283751fb5 100644
--- a/hardware/arduino/sam/variants/arduino_due_x/variant.h
+++ b/hardware/arduino/sam/variants/arduino_due_x/variant.h
@@ -92,6 +92,7 @@ extern "C"{
 #define PIN_SPI_MOSI         (75u)
 #define PIN_SPI_MISO         (74u)
 #define PIN_SPI_SCK          (76u)
+#define SPI_PIN_TO_SPI_CHANNEL(x) (x==PIN_SPI_SS0 ? 0 : (x==PIN_SPI_SS1 ? 1 : (x==PIN_SPI_SS2 ? 2 : 3)))
 
 static const uint8_t SS   = PIN_SPI_SS0 ;
 static const uint8_t SS1  = PIN_SPI_SS1 ;