From 9bc36800b905e2ea6fc93dde0a1d76be80b49e82 Mon Sep 17 00:00:00 2001
From: Kevin <68612569+diyelectromusic@users.noreply.github.com>
Date: Sat, 30 Dec 2023 12:06:10 +0000
Subject: [PATCH] Set USB Gadget name to MiniDexed and fix setting of USB
 product (device) ID.  Fixes #416 (#593)

---
 build.sh                     |  2 +-
 src/kernel.cpp               |  4 +-
 src/usbminidexedmidigadget.h | 86 ++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 3 deletions(-)
 create mode 100644 src/usbminidexedmidigadget.h

diff --git a/build.sh b/build.sh
index 9e8fc7a..b69ba6b 100755
--- a/build.sh
+++ b/build.sh
@@ -26,7 +26,7 @@ if [ "${USB_VID}" ] ; then
 	OPTIONS="${OPTIONS} -o USB_GADGET_VENDOR_ID=${USB_VID}"
 fi
 if [ "${USB_DID}" ] ; then
-	OPTIONS="${OPTIONS} -o USB_GADGET_DEVICE_ID=${USB_DID}"
+	OPTIONS="${OPTIONS} -o USB_GADGET_DEVICE_ID_BASE=${USB_DID}"
 fi
 
 # Build circle-stdlib library
diff --git a/src/kernel.cpp b/src/kernel.cpp
index e7a3738..c06c386 100644
--- a/src/kernel.cpp
+++ b/src/kernel.cpp
@@ -22,7 +22,7 @@
 #include <circle/synchronize.h>
 #include <assert.h>
 #include <circle/usb/usbhcidevice.h>
-#include <circle/usb/gadget/usbmidigadget.h>
+#include "usbminidexedmidigadget.h"
 
 LOGMODULE ("kernel");
 
@@ -69,7 +69,7 @@ bool CKernel::Initialize (void)
 	if (m_Config.GetUSBGadgetMode())
 	{
 		// Run the USB stack in USB Gadget (device) mode
-		m_pUSB = new CUSBMIDIGadget (&mInterrupt);
+		m_pUSB = new CUSBMiniDexedMIDIGadget (&mInterrupt);
 	}
 	else
 	{
diff --git a/src/usbminidexedmidigadget.h b/src/usbminidexedmidigadget.h
new file mode 100644
index 0000000..bbb5f44
--- /dev/null
+++ b/src/usbminidexedmidigadget.h
@@ -0,0 +1,86 @@
+//
+// usbminidexedmidigadget.h
+//
+// MiniDexed - Dexed FM synthesizer for bare metal Raspberry Pi
+// Copyright (C) 2022  The MiniDexed Team
+//
+// Based on circle/usb/gadget/usbmidigadget.h
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+#ifndef _usbminidexedmidigadget_h
+#define _usbminidexedmidigadget_h
+
+#include <circle/usb/gadget/usbmidigadget.h>
+#include <circle/usb/gadget/usbmidigadgetendpoint.h>
+#include <circle/sysconfig.h>
+#include <assert.h>
+
+class CUSBMiniDexedMIDIGadget : public CUSBMIDIGadget
+{
+private:
+#define MDSTRINGDESCRIPTORS 3
+	const char *const s_MiniDexedStringDescriptor[MDSTRINGDESCRIPTORS] =
+	{
+		"\x04\x03\x09\x04",		// Language ID
+		"probonopd",
+		"MiniDexed"
+	};
+
+public:
+	CUSBMiniDexedMIDIGadget (CInterruptSystem *pInterruptSystem)
+	: CUSBMIDIGadget (pInterruptSystem)
+	{
+	}
+
+	~CUSBMiniDexedMIDIGadget (void)
+	{
+		assert(0);
+	}
+
+protected:
+	// Override GetDescriptor frmo CUSBMIDIGadget.
+	// See CUSBMIDIGadget for details.
+	// This will only act on the DESCRIPOR_STRING.
+	// All other descriptors are returned from USBMIDIGadget.
+	//
+	const void *GetDescriptor (u16 wValue, u16 wIndex, size_t *pLength) override
+	{
+		assert (pLength);
+
+		u8 uchDescIndex = wValue & 0xFF;
+
+		switch (wValue >> 8)
+		{
+		case DESCRIPTOR_STRING:
+			if (!uchDescIndex)
+			{
+				*pLength = (u8) s_MiniDexedStringDescriptor[0][0];
+				return s_MiniDexedStringDescriptor[0];
+			}
+			else if (uchDescIndex < MDSTRINGDESCRIPTORS)
+			{
+				return CUSBMIDIGadget::ToStringDescriptor (s_MiniDexedStringDescriptor[uchDescIndex], pLength);
+			}
+			break;
+
+		default:
+			break;
+		}
+
+		return CUSBMIDIGadget::GetDescriptor(wValue, wIndex, pLength);
+	}
+};
+
+#endif