From 3b033db4afd54cef2f7af2a22ec5957422393722 Mon Sep 17 00:00:00 2001
From: Kevin <68612569+diyelectromusic@users.noreply.github.com>
Date: Sat, 13 Jul 2024 17:21:09 +0100
Subject: [PATCH] Implement USBGadgetPin and appropriate boot messages. (#674)

---
 src/config.cpp    | 27 ++++++++++++++++++---------
 src/config.h      |  7 ++++++-
 src/kernel.cpp    | 28 ++++++++++++++++++++++++++--
 src/minidexed.cpp | 32 +++++++++++++++++++++++++++++---
 4 files changed, 79 insertions(+), 15 deletions(-)

diff --git a/src/config.cpp b/src/config.cpp
index ad55d13..884d7cc 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -22,7 +22,6 @@
 //
 #include "config.h"
 #include "../Synth_Dexed/src/dexed.h"
-#include <circle/gpiopin.h>
 
 CConfig::CConfig (FATFS *pFileSystem)
 :	m_Properties ("minidexed.ini", pFileSystem)
@@ -37,14 +36,9 @@ void CConfig::Load (void)
 {
 	m_Properties.Load ();
 	
-	m_bUSBGadgetMode = m_Properties.GetNumber ("USBGadget", 0) != 0;
-	unsigned usbGadgetPinNumber = m_Properties.GetNumber ("USBGadgetPin", 26); // Default to GPIO pin 26 if not specified
-	CGPIOPin usbGadgetPin(usbGadgetPinNumber, GPIOModeInputPullUp);
-	
-	if (usbGadgetPin.Read() == 0)  // If the pin is pulled down
-	{
-		m_bUSBGadgetMode = true;
-	}
+	m_bUSBGadget = m_Properties.GetNumber ("USBGadget", 0) != 0;
+	m_nUSBGadgetPin = m_Properties.GetNumber ("USBGadgetPin", 0); // Default OFF
+	SetUSBGadgetMode(m_bUSBGadget); // Might get overriden later by USBGadgetPin state
 
 	m_SoundDevice = m_Properties.GetString ("SoundDevice", "pwm");
 
@@ -183,11 +177,26 @@ void CConfig::Load (void)
 	m_bPerformanceSelectChannel = m_Properties.GetNumber ("PerformanceSelectChannel", 0);
 }
 
+bool CConfig::GetUSBGadget (void) const
+{
+	return m_bUSBGadget;
+}
+
+unsigned CConfig::GetUSBGadgetPin (void) const
+{
+	return m_nUSBGadgetPin;
+}
+
 bool CConfig::GetUSBGadgetMode (void) const
 {
 	return m_bUSBGadgetMode;
 }
 
+void CConfig::SetUSBGadgetMode (bool USBGadgetMode)
+{
+	m_bUSBGadgetMode = USBGadgetMode;
+}
+
 const char *CConfig::GetSoundDevice (void) const
 {
 	return m_SoundDevice.c_str ();
diff --git a/src/config.h b/src/config.h
index 5944dd2..7497c21 100644
--- a/src/config.h
+++ b/src/config.h
@@ -68,7 +68,10 @@ public:
 	void Load (void);
 	
 	// USB Mode
-	bool GetUSBGadgetMode (void) const;	// true if in USB gadget mode
+	bool GetUSBGadget (void) const;
+	unsigned GetUSBGadgetPin (void) const;
+	bool GetUSBGadgetMode (void) const;	// true if in USB gadget mode depending on USBGadget and USBGadgetPin
+	void SetUSBGadgetMode (bool USBGadgetMode);
 
 	// Sound device
 	const char *GetSoundDevice (void) const;
@@ -192,6 +195,8 @@ public:
 private:
 	CPropertiesFatFsFile m_Properties;
 	
+	bool m_bUSBGadget;
+	unsigned m_nUSBGadgetPin;
 	bool m_bUSBGadgetMode;
 
 	std::string m_SoundDevice;
diff --git a/src/kernel.cpp b/src/kernel.cpp
index 33bc5f8..446747b 100644
--- a/src/kernel.cpp
+++ b/src/kernel.cpp
@@ -20,6 +20,7 @@
 #include "kernel.h"
 #include <circle/logger.h>
 #include <circle/synchronize.h>
+#include <circle/gpiopin.h>
 #include <assert.h>
 #include <circle/usb/usbhcidevice.h>
 #include "usbminidexedmidigadget.h"
@@ -92,8 +93,30 @@ bool CKernel::Initialize (void)
 			m_pSPIMaster = nullptr;
 		}
 	}
-	
-	if (m_Config.GetUSBGadgetMode())
+
+	bool bUSBGadgetMode = false;
+	if (m_Config.GetUSBGadget())
+	{
+		unsigned nUSBGadgetPin = m_Config.GetUSBGadgetPin();
+		if (nUSBGadgetPin == 0)
+		{
+			// No hardware config option
+			bUSBGadgetMode = true;
+		}
+		else
+		{
+			// State of USB Gadget Mode determined by state of the pin.
+			// Pulled down = enable USB Gadget mode
+			CGPIOPin usbGadgetPin(nUSBGadgetPin, GPIOModeInputPullUp);
+
+			if (usbGadgetPin.Read() == 0)
+			{
+				bUSBGadgetMode = true;
+			}
+		}
+	}
+
+	if (bUSBGadgetMode)
 	{
 #if RASPPI==5
 #warning No support for USB Gadget Mode on RPI 5 yet
@@ -107,6 +130,7 @@ bool CKernel::Initialize (void)
 		// Run the USB stack in USB Host (default) mode
 		m_pUSB = new CUSBHCIDevice (&mInterrupt, &mTimer, TRUE);
 	}
+	m_Config.SetUSBGadgetMode(bUSBGadgetMode);
 
     if (!m_pUSB->Initialize ())
     {
diff --git a/src/minidexed.cpp b/src/minidexed.cpp
index 429fddc..da9e598 100644
--- a/src/minidexed.cpp
+++ b/src/minidexed.cpp
@@ -102,17 +102,43 @@ CMiniDexed::CMiniDexed (CConfig *pConfig, CInterruptSystem *pInterrupt,
 		m_pTG[i]->activate ();
 	}
 		
-	if (pConfig->GetUSBGadgetMode())
+	unsigned nUSBGadgetPin = pConfig->GetUSBGadgetPin();
+	bool bUSBGadget = pConfig->GetUSBGadget();
+	bool bUSBGadgetMode = pConfig->GetUSBGadgetMode();
+		
+	if (bUSBGadgetMode)
 	{
 #if RASPPI==5
 		LOGNOTE ("USB Gadget (Device) Mode NOT supported on RPI 5");
 #else
-		LOGNOTE ("USB In Gadget (Device) Mode");
+		if (nUSBGadgetPin == 0)
+		{
+			LOGNOTE ("USB In Gadget (Device) Mode");
+		}
+		else
+		{
+			LOGNOTE ("USB In Gadget (Device) Mode [USBGadgetPin %d = LOW]", nUSBGadgetPin);
+		}
 #endif
 	}
 	else
 	{
-		LOGNOTE ("USB In Host Mode");
+		if (bUSBGadget)
+		{
+			if (nUSBGadgetPin == 0)
+			{
+				// This shouldn't be possible...
+				LOGNOTE ("USB State Unknown");
+			}
+			else
+			{
+				LOGNOTE ("USB In Host Mode [USBGadgetPin %d = HIGH]", nUSBGadgetPin);
+			}
+		}
+		else
+		{
+			LOGNOTE ("USB In Host Mode");
+		}
 	}
 
 	for (unsigned i = 0; i < CConfig::MaxUSBMIDIDevices; i++)