Allow setting of more advanced SPI parameters: mode and clock.

src/config.cpp

@@ -103,6 +103,9 @@ void CConfig::Load (void)
 	m_bSSD1306LCDMirror = m_Properties.GetNumber ("SSD1306LCDMirror", 0) != 0;
 
 	m_nSPIBus = m_Properties.GetNumber ("SPIBus", SPI_INACTIVE);  // Disabled by default
+	m_nSPIMode = m_Properties.GetNumber ("SPIMode", SPI_DEF_MODE);
+	m_nSPIClockKHz = m_Properties.GetNumber ("SPIClockKHz", SPI_DEF_CLOCK);
+
 	m_bST7789Enabled = m_Properties.GetNumber ("ST7789Enabled", 0) != 0;
 	m_nST7789Data = m_Properties.GetNumber ("ST7789Data", 0);
 	m_nST7789Select = m_Properties.GetNumber ("ST7789Select", 0);
@@ -314,6 +317,16 @@ unsigned CConfig::GetSPIBus (void) const
 	return m_nSPIBus;
 }
 
+unsigned CConfig::GetSPIMode (void) const
+{
+	return m_nSPIMode;
+}
+
+unsigned CConfig::GetSPIClockKHz (void) const
+{
+	return m_nSPIClockKHz;
+}
+
 bool CConfig::GetST7789Enabled (void) const
 {
 	return m_bST7789Enabled;

src/config.h

@@ -29,10 +29,8 @@
 #include <string>
 
 #define SPI_INACTIVE	255
-#define SPI_CLOCK_SPEED	15000000	// Hz
-#define SPI_CPOL	0		// Taken from circle sample application
-#define SPI_CPHA	0		// Apparently Mode 0 (0,0) is common...?
-
+#define SPI_DEF_CLOCK	15000	// kHz
+#define SPI_DEF_MODE	0		// Default mode (0,1,2,3)
 
 class CConfig		// Configuration for MiniDexed
 {
@@ -109,8 +107,12 @@ public:
 	bool     GetSSD1306LCDRotate (void) const;
 	bool     GetSSD1306LCDMirror (void) const;
 
-	// ST7789 LCD
+	// SPI support
 	unsigned GetSPIBus (void) const;
+	unsigned GetSPIMode (void) const;
+	unsigned GetSPIClockKHz (void) const;
+
+	// ST7789 LCD
 	bool GetST7789Enabled (void) const;
 	unsigned GetST7789Data (void) const;
 	unsigned GetST7789Select (void) const;
@@ -223,6 +225,9 @@ private:
 	bool     m_bSSD1306LCDMirror;
 
 	unsigned m_nSPIBus;
+	unsigned m_nSPIMode;
+	unsigned m_nSPIClockKHz;
+
 	bool     m_bST7789Enabled;
 	unsigned m_nST7789Data;
 	unsigned m_nST7789Select;

src/kernel.cpp

@@ -68,6 +68,8 @@ bool CKernel::Initialize (void)
 	m_Config.Load ();
 	
 	unsigned nSPIMaster = m_Config.GetSPIBus();
+	unsigned nSPIMode = m_Config.GetSPIMode();
+	unsigned long nSPIClock = 1000 * m_Config.GetSPIClockKHz();
 #if RASPPI<4
 	// By default older RPI versions use SPI 0.
 	// It is possible to build circle to support SPI 1 for
@@ -81,7 +83,9 @@ bool CKernel::Initialize (void)
 	if (nSPIMaster == 0 || nSPIMaster == 3 || nSPIMaster == 4 || nSPIMaster == 5 || nSPIMaster == 6)
 #endif
 	{
-		m_pSPIMaster = new CSPIMaster (SPI_CLOCK_SPEED, SPI_CPOL, SPI_CPHA, nSPIMaster);
+		unsigned nCPHA = (nSPIMode & 1) ? 1 : 0;
+		unsigned nCPOL = (nSPIMode & 2) ? 1 : 0;
+		m_pSPIMaster = new CSPIMaster (nSPIClock, nCPOL, nCPHA, nSPIMaster);
 		if (!m_pSPIMaster->Initialize())
 		{
 			delete (m_pSPIMaster);

src/userinterface.cpp

@@ -79,13 +79,18 @@ bool CUserInterface::Initialize (void)
 				return false;
 			}
 
+			unsigned long nSPIClock = 1000 * m_pConfig->GetSPIClockKHz();
+			unsigned nSPIMode = m_pConfig->GetSPIMode();
+			unsigned nCPHA = (nSPIMode & 1) ? 1 : 0;
+			unsigned nCPOL = (nSPIMode & 2) ? 1 : 0;
+			LOGDBG("SPI: CPOL=%u; CPHA=%u; CLK=%u",nCPOL,nCPHA,nSPIClock);
 			m_pST7789Display = new CST7789Display (m_pSPIMaster,
 							m_pConfig->GetST7789Data(),
 							m_pConfig->GetST7789Reset(),
 							m_pConfig->GetST7789Backlight(),
 							m_pConfig->GetST7789Width(),
 							m_pConfig->GetST7789Height(),
-							SPI_CPOL, SPI_CPHA, SPI_CLOCK_SPEED,
+							nCPOL, nCPHA, nSPIClock,
 							m_pConfig->GetST7789Select());
 			if (m_pST7789Display->Initialize())
 			{