From 0c873577dd0f2953cafc7516d3bd4dcb26559f7e Mon Sep 17 00:00:00 2001
From: Markus Tavenrath <github@tavenrath.com>
Date: Sat, 30 Apr 2016 18:18:08 +0200
Subject: [PATCH] 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

	modified:   sming/core/SPI.cpp
	modified:   sming/core/SPISettings.cpp
	modified:   sming/core/SPISettings.h
---
 sming/sming/core/SPI.cpp         | 5 ++---
 sming/sming/core/SPISettings.cpp | 2 --
 sming/sming/core/SPISettings.h   | 1 -
 3 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/sming/sming/core/SPI.cpp b/sming/sming/core/SPI.cpp
index b2c2575..0618c75 100644
--- a/sming/sming/core/SPI.cpp
+++ b/sming/sming/core/SPI.cpp
@@ -125,7 +125,7 @@ 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 +193,7 @@ 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);
 
@@ -261,7 +261,6 @@ void SPIClass::prepare(SPISettings mySettings) {
 #endif
 
 	_SPISettings = mySettings;
-	mySettings._user_regvalue = SPI_USER(SPI_NO);
 	_init = true;
 };
 
diff --git a/sming/sming/core/SPISettings.cpp b/sming/sming/core/SPISettings.cpp
index be6de2b..4f0e9f7 100644
--- a/sming/sming/core/SPISettings.cpp
+++ b/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;
 }
 
 
diff --git a/sming/sming/core/SPISettings.h b/sming/sming/core/SPISettings.h
index 1c2780f..f138e5f 100644
--- a/sming/sming/core/SPISettings.h
+++ b/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;