How to get device instance id for COM port

Question

How can I programatically find out device instance id for COM port. In my case the COM port is an virtual FTDI COM port. In Device manager / Details / Device instance path I can see
FTDIBUS\VID_0403+PID_6015+DN04P3D2A\0000.

In my application, I open the com port using:
comHandle = CreateFileA("\\.\com10", GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0);

Now I wonder if the comHandle could be used for determining the device id. Or maybe the device id could be recognized directly from the com port number?

I need the device id for restarting the device. I use devcon source code functions for it and thus I am able to simulate devcon restart @FTDIBUS\VID_0403+PID_6015+DN04P3D2A\0000 command in my application. But I need to identify the correct device id for the particular COM port.

Thank you for any help

Answer 1

You can use SetupDiGetDeviceInstanceId

A quick test with GUID_SERENUM_BUS_ENUMERATOR =>

	HDEVINFO DeviceInfoSet = SetupDiGetClassDevs(&GUID_SERENUM_BUS_ENUMERATOR, NULL, NULL, DIGCF_DEVICEINTERFACE | DIGCF_PRESENT);  
	SP_DEVINFO_DATA DeviceInfoData;  
	DeviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);  
	for (DWORD dwDeviceIndex = 0; SetupDiEnumDeviceInfo(DeviceInfoSet, dwDeviceIndex, &DeviceInfoData); dwDeviceIndex++)  
	{  
		SP_DEVICE_INTERFACE_DATA DeviceInterfaceData;  
		DeviceInterfaceData.cbSize = sizeof(SP_DEVICE_INTERFACE_DATA);  
		for (DWORD dwMemberIndex = 0; SetupDiEnumDeviceInterfaces(DeviceInfoSet, &DeviceInfoData, &GUID_SERENUM_BUS_ENUMERATOR, dwMemberIndex, &DeviceInterfaceData); dwMemberIndex++)  
		{  
			DWORD dwDeviceInterfaceDetailDataSize = offsetof(SP_DEVICE_INTERFACE_DETAIL_DATA, DevicePath) + MAX_PATH * sizeof(TCHAR);  
			PSP_DEVICE_INTERFACE_DETAIL_DATA pDeviceInterfaceDetailData = (PSP_DEVICE_INTERFACE_DETAIL_DATA)new BYTE[dwDeviceInterfaceDetailDataSize];  
			pDeviceInterfaceDetailData->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);  
			if (SetupDiGetDeviceInterfaceDetail(DeviceInfoSet, &DeviceInterfaceData, pDeviceInterfaceDetailData, dwDeviceInterfaceDetailDataSize, NULL, NULL))  
			{  
				DWORD dwRegType;  
				WCHAR wsPropertyBuffer[256] = L"";  
				BOOL bRet = SetupDiGetDeviceRegistryProperty(DeviceInfoSet, &DeviceInfoData, SPDRP_FRIENDLYNAME, &dwRegType, (BYTE*)wsPropertyBuffer, 256, NULL);  
				ULONG nSize = 0;  
				WCHAR wsInstanceId[255] = L"";  
				SetupDiGetDeviceInstanceId(DeviceInfoSet, &DeviceInfoData, wsInstanceId, nSize, &nSize);  
				bRet = SetupDiGetDeviceInstanceId(DeviceInfoSet, &DeviceInfoData, wsInstanceId, nSize, &nSize);  

				WCHAR wsText[255] = L"";  
				swprintf(wsText, L"Name : %s\r\n", wsPropertyBuffer);  
				OutputDebugString(wsText);  
				swprintf(wsText, L"InstanceId : %s\r\n", wsInstanceId);  
				OutputDebugString(wsText);  

				delete[] pDeviceInterfaceDetailData;					  
			}  
		}  
	}