Fix issue #109, SPI needs to read register SPI_USER(SPI_NO) instead of using the value SPI_USER(SPI_NO) as base value for SPI_USER in SPI::transfer and SPI::transfer32

Author: mtavenrath

sming/sming/core/SPI.cpp

@@ -88,6 +88,10 @@ void SPIClass::beginTransaction(SPISettings mySettings) {
 #ifdef SPI_DEBUG
 	debugf("SPIhw::beginTransaction(SPISettings mySettings)");
 #endif
+	
+	// store SPI user register
+	_userReg = READ_PERI_REG(SPI_USER(SPI_NO));
+
 	// check if we need to change settings
 	if (this->_SPISettings == mySettings)
 		return;
@@ -108,6 +112,10 @@ void SPIClass::endTransaction() {
 #ifdef SPI_DEBUG
 	debugf("SPIhw::endTransaction()");
 #endif
+	
+	// restore SPI user register
+        WRITE_PERI_REG(SPI_USER(SPI_NO), _userReg);
+	_userReg = 0;
 };
 
 /* @defgroup SPI hardware implementation
@@ -125,7 +133,7 @@ void SPIClass::endTransaction() {
 uint32 SPIClass::transfer32(uint32 data, uint8 bits)
 {
 	// restore inital SPI_USER register
-	uint32_t regvalue = _SPISettings._user_regvalue;
+	uint32_t regvalue = READ_PERI_REG(SPI_USER(SPI_NO));
 
 	while(READ_PERI_REG(SPI_CMD(SPI_NO))&SPI_USR);
 
@@ -193,7 +201,7 @@ void SPIClass::transfer(uint8 *buffer, size_t numberBytes) {
 		num_bits = bufLenght * 8;
 
 		// restore inital SPI_USER register
-		uint32_t regvalue = _SPISettings._user_regvalue;
+		uint32_t regvalue = READ_PERI_REG(SPI_USER(SPI_NO));
 
 		while(READ_PERI_REG(SPI_CMD(SPI_NO))&SPI_USR);
 
@@ -242,9 +250,9 @@ void SPIClass::prepare(SPISettings mySettings) {
 	debugf("SPIClass::prepare(SPISettings mySettings)");
 	mySettings.print("mySettings");
 #endif
-
+	
 	// check if we need to change settings
-	if (_init & _SPISettings == mySettings)
+	if (_init && _SPISettings == mySettings)
 		return;
 
 	//  setup clock
@@ -261,7 +269,6 @@ void SPIClass::prepare(SPISettings mySettings) {
 #endif
 
 	_SPISettings = mySettings;
-	mySettings._user_regvalue = SPI_USER(SPI_NO);
 	_init = true;
 };
 
@@ -441,7 +448,7 @@ void SPIClass::setFrequency(int freq) {
 	int _CPU_freq = system_get_cpu_freq() * 10000000UL;
 
 	// dont run code if there are no changes
-	if (_init & freq == _SPISettings._speed) return;
+	if (_init && freq == _SPISettings._speed) return;
 
 	// run full speed -> do not use any dividers
 	if (freq == _CPU_freq) {

sming/sming/core/SPI.h

@@ -106,6 +106,24 @@ class SPIClass: public SPIBase {
 	virtual unsigned short transfer16(unsigned short val) {
 		return transfer32((uint32)val, 16);
 	};
+        
+	/** @brief 	transfer32()
+	 * @param	short to send
+	 * @retval	short received
+	 *
+	 * calls private method transfer32(byte) to send/recv one uint32_t
+	 * input/output casted to rightdta type
+	 *
+	 * SPI transfer is based on a simultaneous send and receive:
+	 * the received data is returned in receivedVal (or receivedVal16).
+	 *
+	 * 		receivedVal = SPI.transfer(val)	        : single byte
+	 * 		receivedVal32 = SPI.transfer32(val32)	: single uint32_t
+	 */
+	virtual uint32_t transfer32(uint32_t val) {
+		return transfer32((uint32_t) val, 32);
+	};
+        
 
 	/** @brief 	transfer(uint8 *buffer, size_t numberBytes)
 	 * @param	buffer in/out
@@ -168,9 +186,10 @@ class SPIClass: public SPIBase {
 	uint32_t getFrequency(int freq, int &pre, int clk);
 	void setFrequency(int freq);
 
-	SPISettings _SPISettings;
-	uint8	_isTX = false;
-	uint8	_init = false;
+	SPISettings 	_SPISettings;
+	uint8		_isTX = false;
+	uint8		_init = false;
+	uint32_t	_userReg = 0;
 
 };
 

sming/sming/core/SPISettings.cpp

@@ -21,7 +21,6 @@ SPISettings::SPISettings() {
 	_speed = 4000000;
 	_byteOrder = MSBFIRST;
 	_dataMode = SPI_MODE0;
-	_user_regvalue = 0;
 }
 
 /*
@@ -38,7 +37,6 @@ SPISettings::SPISettings(int speed, uint8 byteOrder, uint8 dataMode) {
 	_speed = speed;
 	_byteOrder = byteOrder;
 	_dataMode = dataMode;
-	_user_regvalue = 0;
 }
 
 

sming/sming/core/SPISettings.h

@@ -67,7 +67,6 @@ class SPISettings {
 	int 	_speed;
 	uint8	_byteOrder;
 	uint8	_dataMode;
-	uint32_t _user_regvalue;
 
 	// overload operator to check wheter the settings are equal
 	bool operator==(const SPISettings &other) const;