Fixed LowLevel JoystickHostWithParser demo not saving the chosen HID interface's report descriptor size.

Simplified low level Host demo configuration descriptor parser routines.

1 files changed, 24 insertions, 12 deletions

diff --git a/Demos/Host/LowLevel/JoystickHostWithParser/ConfigDescriptor.c b/Demos/Host/LowLevel/JoystickHostWithParser/ConfigDescriptor.c
index 1d8265043..3eaf7d960 100644
--- a/Demos/Host/LowLevel/JoystickHostWithParser/ConfigDescriptor.c
+++ b/Demos/Host/LowLevel/JoystickHostWithParser/ConfigDescriptor.c
@@ -51,7 +51,9 @@ uint8_t ProcessConfigurationDescriptor(void)
 	void*    CurrConfigLocation = ConfigDescriptorData;
 	uint16_t CurrConfigBytesRem;
 	
-	USB_Descriptor_Endpoint_t* DataINEndpoint = NULL;
+	USB_Descriptor_Interface_t* HIDInterface   = NULL;
+	USB_Descriptor_HID_t*       HIDDescriptor  = NULL;
+	USB_Descriptor_Endpoint_t*  DataINEndpoint = NULL;
 
 	/* Retrieve the entire configuration descriptor into the allocated buffer */
 	switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
@@ -65,19 +67,12 @@ uint8_t ProcessConfigurationDescriptor(void)
 		default:
 			return ControlError;
 	}
-	
-	/* Get the first HID interface from the configuration descriptor */
-	if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
-	                              DComp_NextJoystickInterface) != DESCRIPTOR_SEARCH_COMP_Found)
-	{
-		/* Descriptor not found, error out */
-		return NoCompatibleInterfaceFound;
-	}
 
 	while (!(DataINEndpoint))
 	{
-		/* Get the next HID interface's data endpoint descriptor */
-		if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 		                              DComp_NextJoystickInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
 		{
 			/* Get the next HID interface from the configuration descriptor */
@@ -88,6 +83,20 @@ uint8_t ProcessConfigurationDescriptor(void)
 				return NoCompatibleInterfaceFound;
 			}
 
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Get the HID descriptor from the configuration descriptor */
+			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+										  DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
+			{
+				/* Descriptor not found, error out */
+				return NoCompatibleInterfaceFound;
+			}
+
+			/* Save the HID descriptor for later use */
+			HIDDescriptor = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_HID_t);	
+
 			/* Skip the remainder of the loop as we have not found an endpoint yet */
 			continue;
 		}
@@ -104,7 +113,10 @@ uint8_t ProcessConfigurationDescriptor(void)
 	Pipe_ConfigurePipe(JOYSTICK_DATA_IN_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN,
 	                   DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 	Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS);
-			
+
+	/* Get the HID report size from the HID report descriptor */
+	HIDReportSize = HIDDescriptor->HIDReportLength;
+
 	/* Valid data found, return success */
 	return SuccessfulConfigRead;
 }