Support for ST7789 based (SPI) displays (#652)

* Initial build with basic structure to support st7789device once added to circle.

* Implementation of ST7789 display - requires updated circle with new ST7789 character driver.

* Added more details to minidexed.ini about ST7789 and SPI options.

* Update to develop branch of circle that now supports st7789 character mode display.

* Minor formatting fixes to tidy up.

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

* Update to allow for font size as an option.

src/config.cpp

@@ -102,6 +102,20 @@ void CConfig::Load (void)
 	m_bSSD1306LCDRotate = m_Properties.GetNumber ("SSD1306LCDRotate", 0) != 0;
 	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);
+	m_nST7789Reset = m_Properties.GetNumber ("ST7789Reset", 0);  // optional
+	m_nST7789Backlight = m_Properties.GetNumber ("ST7789Backlight", 0);  // optional
+	m_nST7789Width = m_Properties.GetNumber ("ST7789Width", 240);
+	m_nST7789Height = m_Properties.GetNumber ("ST7789Height", 240);
+	m_nST7789Rotation = m_Properties.GetNumber ("ST7789Rotation", 0);
+	m_bST7789SmallFont = m_Properties.GetNumber ("ST7789SmallFont", 0) != 0;
+
 	m_nLCDColumns = m_Properties.GetNumber ("LCDColumns", 16);
 	m_nLCDRows = m_Properties.GetNumber ("LCDRows", 2);
 
@@ -299,6 +313,65 @@ bool CConfig::GetSSD1306LCDMirror (void) const
 	return m_bSSD1306LCDMirror;
 }
 
+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;
+}
+
+unsigned CConfig::GetST7789Data (void) const
+{
+	return m_nST7789Data;
+}
+
+unsigned CConfig::GetST7789Select (void) const
+{
+	return m_nST7789Select;
+}
+
+unsigned CConfig::GetST7789Reset (void) const
+{
+	return m_nST7789Reset;
+}
+
+unsigned CConfig::GetST7789Backlight (void) const
+{
+	return m_nST7789Backlight;
+}
+
+unsigned CConfig::GetST7789Width (void) const
+{
+	return m_nST7789Width;
+}
+
+unsigned CConfig::GetST7789Height (void) const
+{
+	return m_nST7789Height;
+}
+
+unsigned CConfig::GetST7789Rotation (void) const
+{
+	return m_nST7789Rotation;
+}
+
+bool CConfig::GetST7789SmallFont (void) const
+{
+	return m_bST7789SmallFont;
+}
 unsigned CConfig::GetLCDColumns (void) const
 {
 	return m_nLCDColumns;

src/config.h

@@ -28,6 +28,10 @@
 #include <circle/sysconfig.h>
 #include <string>
 
+#define SPI_INACTIVE	255
+#define SPI_DEF_CLOCK	15000	// kHz
+#define SPI_DEF_MODE	0		// Default mode (0,1,2,3)
+
 class CConfig		// Configuration for MiniDexed
 {
 public:
@@ -103,6 +107,22 @@ class CConfig		// Configuration for MiniDexed
 	bool     GetSSD1306LCDRotate (void) const;
 	bool     GetSSD1306LCDMirror (void) const;
 
+	// 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;
+	unsigned GetST7789Reset (void) const;
+	unsigned GetST7789Backlight (void) const;
+	unsigned GetST7789Width (void) const;
+	unsigned GetST7789Height (void) const;
+	unsigned GetST7789Rotation (void) const;
+	bool     GetST7789SmallFont (void) const;
+
 	unsigned GetLCDColumns (void) const;
 	unsigned GetLCDRows (void) const;
 
@@ -204,7 +224,21 @@ class CConfig		// Configuration for MiniDexed
 	unsigned m_nSSD1306LCDHeight;
 	bool     m_bSSD1306LCDRotate;
 	bool     m_bSSD1306LCDMirror;
-
+
+	unsigned m_nSPIBus;
+	unsigned m_nSPIMode;
+	unsigned m_nSPIClockKHz;
+
+	bool     m_bST7789Enabled;
+	unsigned m_nST7789Data;
+	unsigned m_nST7789Select;
+	unsigned m_nST7789Reset;
+	unsigned m_nST7789Backlight;
+	unsigned m_nST7789Width;
+	unsigned m_nST7789Height;
+	unsigned m_nST7789Rotation;
+	unsigned m_bST7789SmallFont;
+
 	unsigned m_nLCDColumns;
 	unsigned m_nLCDRows;
 

src/kernel.cpp

@@ -33,6 +33,7 @@ CKernel::CKernel (void)
 	m_Config (&mFileSystem),
 	m_GPIOManager (&mInterrupt),
  	m_I2CMaster (CMachineInfo::Get ()->GetDevice (DeviceI2CMaster), TRUE),
+	m_pSPIMaster (nullptr),
 	m_pDexed (0)
 {
 	s_pThis = this;
@@ -66,6 +67,32 @@ 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
+	// devices that use the 40-pin header, but that isn't
+	// enabled at present...
+	if (nSPIMaster == 0)
+#else
+	// RPI 4+ has several possible SPI Bus Configurations.
+	// As mentioned above, SPI 1 is not built by default.
+	// See circle/include/circle/spimaster.h
+	if (nSPIMaster == 0 || nSPIMaster == 3 || nSPIMaster == 4 || nSPIMaster == 5 || nSPIMaster == 6)
+#endif
+	{
+		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);
+			m_pSPIMaster = nullptr;
+		}
+	}
+
 	if (m_Config.GetUSBGadgetMode())
 	{
 #if RASPPI==5
@@ -86,7 +113,7 @@ bool CKernel::Initialize (void)
 		return FALSE;
     }
 
-	m_pDexed = new CMiniDexed (&m_Config, &mInterrupt, &m_GPIOManager, &m_I2CMaster,
+	m_pDexed = new CMiniDexed (&m_Config, &mInterrupt, &m_GPIOManager, &m_I2CMaster, m_pSPIMaster,
 				   &mFileSystem);
 	assert (m_pDexed);
 

src/kernel.h

@@ -24,6 +24,7 @@
 #include <circle/cputhrottle.h>
 #include <circle/gpiomanager.h>
 #include <circle/i2cmaster.h>
+#include <circle/spimaster.h>
 #include <circle/usb/usbcontroller.h>
 #include "config.h"
 #include "minidexed.h"
@@ -54,6 +55,7 @@ class CKernel : public CStdlibAppStdio
 	CCPUThrottle	m_CPUThrottle;
 	CGPIOManager	m_GPIOManager;
 	CI2CMaster	m_I2CMaster;
+	CSPIMaster	*m_pSPIMaster;
 	CMiniDexed	*m_pDexed;
 	CUSBController *m_pUSB;
 

src/minidexed.cpp

@@ -31,13 +31,13 @@
 LOGMODULE ("minidexed");
 
 CMiniDexed::CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
-			CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, FATFS *pFileSystem)
+			CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, CSPIMaster *pSPIMaster, FATFS *pFileSystem)
 :
 #ifdef ARM_ALLOW_MULTI_CORE
 	CMultiCoreSupport (CMemorySystem::Get ()),
 #endif
 	m_pConfig (pConfig),
-	m_UI (this, pGPIOManager, pI2CMaster, pConfig),
+	m_UI (this, pGPIOManager, pI2CMaster, pSPIMaster, pConfig),
 	m_PerformanceConfig (pFileSystem),
 	m_PCKeyboard (this, pConfig, &m_UI),
 	m_SerialMIDI (this, pInterrupt, pConfig, &m_UI),

src/minidexed.h

@@ -36,6 +36,7 @@
 #include <circle/interrupt.h>
 #include <circle/gpiomanager.h>
 #include <circle/i2cmaster.h>
+#include <circle/spimaster.h>
 #include <circle/multicore.h>
 #include <circle/sound/soundbasedevice.h>
 #include <circle/spinlock.h>
@@ -51,7 +52,7 @@ class CMiniDexed
 {
 public:
 	CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
-		    CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, FATFS *pFileSystem);
+		    CGPIOManager *pGPIOManager, CI2CMaster *pI2CMaster, CSPIMaster *pSPIMaster, FATFS *pFileSystem);
 
 	bool Initialize (void);
 

src/minidexed.ini

@@ -55,6 +55,27 @@ SSD1306LCDHeight=32
 SSD1306LCDRotate=0
 SSD1306LCDMirror=0
 
+# ST7789 LCD
+# SPIBus=0 for any RPi (GPIO 10,11,8,7).
+#     Note: Leave blank (default) if no SPI device required.
+# Select=0|1 for CE0 or CE1
+# Data = GPIO pin number
+# Optional: Reset, Backlight = GPIO pin numbers
+# Rotation=0,90,180,270
+# SmallFont=0 (default), 1
+#
+# For a 240 wide display set LCDColumns=15 with LCDRows=2
+SPIBus=
+ST7789Enabled=0
+ST7789Data=
+ST7789Select=
+ST7789Reset=
+ST7789Backlight=
+ST7789Width=240
+ST7789Height=240
+ST7789Rotation=0
+ST7789SmallFont=0
+
 # Default is 16x2 display (e.g. HD44780)
 LCDColumns=16
 LCDRows=2