From ede87e067dadd07119f24e96261b66ac92b3af6f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C3=A9vin=20Redon?= <kredon@sysmocom.de>
Date: Tue, 13 Aug 2019 17:03:11 +0200
Subject: [PATCH] USB: place version string in interface

previously the version string was in the iConfiguration field of a
dedicated USB configuration.
this configuration had no interface, but the USB specification
requires at least one interface.
an interface has been added to this configuration.
the version string is now in the iInterface field, and the
iConfiguration field contains "firmware version".
the USB specification does not require an end-point, and none are
present.

Change-Id: I99361e313979711f4f45ad424a52faa3ddd7c558
---
 firmware/libcommon/source/usb.c | 43 ++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/firmware/libcommon/source/usb.c b/firmware/libcommon/source/usb.c
index 9d3072fa..e75646e5 100644
--- a/firmware/libcommon/source/usb.c
+++ b/firmware/libcommon/source/usb.c
@@ -62,6 +62,7 @@ enum strDescNum {
 	CARDEM_USIM4_INTF_STR,
 	// runtime strings
 	SERIAL_STR,
+	VERSION_CONF_STR,
 	VERSION_STR,
 	// count
 	STRING_DESC_CNT
@@ -69,7 +70,7 @@ enum strDescNum {
 
 /** array of static (from usb_strings) and runtime (serial, version) USB strings
  */
-static const unsigned char *usb_strings_extended[ARRAY_SIZE(usb_strings) + 2];
+static const unsigned char *usb_strings_extended[ARRAY_SIZE(usb_strings) + 3];
 
 /* USB string for the serial (using 128-bit device ID) */
 static unsigned char usb_string_serial[] = {
@@ -110,6 +111,26 @@ static unsigned char usb_string_serial[] = {
 };
 
 /* USB string for the version */
+static const unsigned char usb_string_version_conf[] = {
+	USBStringDescriptor_LENGTH(16),
+	USBGenericDescriptor_STRING,
+	USBStringDescriptor_UNICODE('f'),
+	USBStringDescriptor_UNICODE('i'),
+	USBStringDescriptor_UNICODE('r'),
+	USBStringDescriptor_UNICODE('m'),
+	USBStringDescriptor_UNICODE('w'),
+	USBStringDescriptor_UNICODE('a'),
+	USBStringDescriptor_UNICODE('r'),
+	USBStringDescriptor_UNICODE('e'),
+	USBStringDescriptor_UNICODE(' '),
+	USBStringDescriptor_UNICODE('v'),
+	USBStringDescriptor_UNICODE('e'),
+	USBStringDescriptor_UNICODE('r'),
+	USBStringDescriptor_UNICODE('s'),
+	USBStringDescriptor_UNICODE('i'),
+	USBStringDescriptor_UNICODE('o'),
+	USBStringDescriptor_UNICODE('n'),
+};
 static const char git_version[] = GIT_VERSION;
 static unsigned char usb_string_version[2 + ARRAY_SIZE(git_version) * 2 - 2];
 
@@ -582,21 +603,34 @@ static const SIMTraceDriverConfigurationDescriptorMITM
 typedef struct _SIMTraceDriverConfigurationDescriptorVersion {
 	/** Standard configuration descriptor. */
 	USBConfigurationDescriptor configuration;
+	USBInterfaceDescriptor version;
 } __attribute__ ((packed)) SIMTraceDriverConfigurationDescriptorVersion;
 
 static const SIMTraceDriverConfigurationDescriptorVersion
 				configurationDescriptorVersion = {
-	/* Standard configuration descriptor */
+	/* Standard configuration descriptor for the interface descriptor*/
 	.configuration = {
 		.bLength 		= sizeof(USBConfigurationDescriptor),
 		.bDescriptorType	= USBGenericDescriptor_CONFIGURATION,
 		.wTotalLength		= sizeof(SIMTraceDriverConfigurationDescriptorVersion),
-		.bNumInterfaces		= 0,
+		.bNumInterfaces		= 1,
 		.bConfigurationValue	= CFG_NUM_VERSION,
-		.iConfiguration		= VERSION_STR,
+		.iConfiguration		= VERSION_CONF_STR,
 		.bmAttributes		= USBD_BMATTRIBUTES,
 		.bMaxPower		= USBConfigurationDescriptor_POWER(100),
 	},
+	/* Interface standard descriptor just holding the version information */
+	.version = {
+		.bLength = sizeof(USBInterfaceDescriptor),
+		.bDescriptorType 	= USBGenericDescriptor_INTERFACE,
+		.bInterfaceNumber	= 0,
+		.bAlternateSetting	= 0,
+		.bNumEndpoints		= 0,
+		.bInterfaceClass	= USB_CLASS_PROPRIETARY,
+		.bInterfaceSubClass	= 0xff,
+		.bInterfaceProtocol	= 0,
+		.iInterface		= VERSION_STR,
+	},
 };
 
 const USBConfigurationDescriptor *configurationDescriptorsArr[] = {
@@ -693,6 +727,7 @@ void SIMtrace_USB_Initialize(void)
 		usb_strings_extended[i] = usb_strings[i];
 	}
 	usb_strings_extended[SERIAL_STR] = usb_string_serial;
+	usb_strings_extended[VERSION_CONF_STR] = usb_string_version_conf;
 	usb_strings_extended[VERSION_STR] = usb_string_version;
 
 	// Initialize standard USB driver