how to get vendor id and product id of a plugged u

Question

I am using Qt on windows platform.

i want to get and display vendor id and product id of a plugged usb device from my local system.

Below is my full source code to get the vendor id and product id from the usb device.

when i run the my qt application it does not throw me any errors .

so i plug the usb device into the system.

but my print statement displays the result as below

qDebug ()<<pDetData->DevicePath;

i get the result as 0x4

Whether i have any implementation mistakes in my source code ?

if so please guide me what i am doing wrong..

Have i missed out any other functions ?

Is it possible to get the vendor id and product id from the usb device based on my source code .( my implementation of the code ) ?

kindly find my source code below

static GUID GUID_DEVINTERFACE_USB_DEVICE = { 0xA5DCBF10L, 0x6530, 0x11D2, 
    { 0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED } };

HANDLE hInfo = SetupDiGetClassDevs(&GUID_DEVINTERFACE_USB_DEVICE,NULL,NULL,
    DIGCF_PRESENT | DIGCF_INTERFACEDEVICE);

if ( hInfo == INVALID_HANDLE_VALUE )    
{    
    qDebug ()<<"invalid";   
}    
else    
{        
    qDebug ()<<"valid handle";    

    SP_DEVINFO_DATA DeviceInfoData;
    DeviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA);

    SP_INTERFACE_DEVICE_DATA Interface_Info;    
    Interface_Info.cbSize = sizeof(Interface_Info);

    BYTE Buf[1024];
    DWORD i;
    DWORD InterfaceNumber= 0;

    PSP_DEVICE_INTERFACE_DETAIL_DATA pspdidd = 
        (PSP_DEVICE_INTERFACE_DETAIL_DATA) Buf;

    for (i=0;SetupDiEnumDeviceInfo(hInfo,i,&DeviceInfoData);i++)
    {
        DWORD DataT;
        LPTSTR buffer = NULL;
        DWORD buffersize = 0;

        while (!SetupDiGetDeviceRegistryProperty( hInfo,
            &DeviceInfoData,
            SPDRP_DEVICEDESC,
            &DataT,
            (PBYTE)buffer,
            buffersize,
            &buffersize))    
         {
            if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
            {
                // Change the buffer size.
                if (buffer) LocalFree(buffer);
                buffer = (LPTSTR)LocalAlloc(LPTR,buffersize);
            }
            else
            {
                // Insert error handling here.
                break;
            }

            qDebug ()<<(TEXT("Device Number %i is: %s\n"),i, buffer);

            if (buffer) LocalFree(buffer);

            if ( GetLastError() != NO_ERROR 
                     && GetLastError() != ERROR_NO_MORE_ITEMS )    
            {
                // Insert error handling here.
                qDebug ()<<"return false";
            }

            InterfaceNumber = 0; // this just returns the first one, you can iterate on this

            if (SetupDiEnumDeviceInterfaces(hInfo,
                                   NULL, 
                                   &GUID_DEVINTERFACE_USB_DEVICE,
                                   InterfaceNumber,
                                   &Interface_Info))
            {
                printf("Got interface");
                DWORD needed;
                pspdidd->cbSize = sizeof(*pspdidd);    
                SP_DEVICE_INTERFACE_DETAIL_DATA *pDetData = NULL;
                DWORD dwDetDataSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA) 
                                      + 256;

                SetupDiGetDeviceInterfaceDetail(hInfo, 
                    &Interface_Info, pDetData,dwDetDataSize, NULL,
                    &DeviceInfoData);

                qDebug ()<<pDetData->DevicePath;
                //qDebug ()<<QString::fromWCharArray(pDetData->DevicePath);
            }
            else
            {    
                printf("\nNo interface");

                //ErrorExit((LPTSTR) "SetupDiEnumDeviceInterfaces");

                if ( GetLastError() == ERROR_NO_MORE_ITEMS) 
                    printf(", since there are no more items found.");
                else 
                    printf(", unknown reason.");

            }
            // Cleanup

            SetupDiDestroyDeviceInfoList(hInfo);
            qDebug ()<<"return true";
        }
    }
}

--------------- Edited to add: -----------------

Hi... the application comes and prints this

\?\usb#vid_04f2&pid_0111#5&1ba5a77f&0&2#{a5dcbf1 0-6530-11d2-901f-00c04fb951ed}

again it goes to while loop .... here it gets breaked in the else statement...

Qt Code:

if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) { 
    // Change the buffer size. 
    if (buffer) LocalFree(buffer); 
    buffer = (LPTSTR)LocalAlloc(LPTR,buffersize); 
} else { 
    qDebug ()<<"Here it quits the application"; 
    // Insert error handling here. break; 
} 

Any ideas in this....

Answer 1

You are enumerating the device "interface". Interfaces do not have a VID or PID - device instances do. I am not sure whether you are enumerating the interfaces to narrow down the devices you are interested in, for because it's an error.

If you just enumerate the device instances, then you can call SetupDiGetDeviceProperty with DEVPKEY_Device_HardwareIds and then grep the resulting hardware id for the VID and PID.

If you are using the device interfaces on purpose, then you need to call SetupDiGetDeviceInterfaceDetail once with a NULL PSP_DEVICE_INTERFACE_DETAIL parameter and a valid requiredSize pointer to get the required size of memory to allocate, allocate that memory and then call the function again. In that call, the last parameter is a SP_DEVINFO_DATA structure, which once retrieved, you can use in the call to SetupDiGetDeviceProperty as I mentioned above.

Answer 2

An alternative is to obtain the hardwareID which includes the VID and PID.

Call SetupDiGetDeviceRegistryProperty with SPDRP_HARDWAREID like so:

wchar_t *hardwareID;

// First get requiredLength
SetupDiGetDeviceRegistryProperty(deviceInfoList, &deviceInfoData, SPDRP_HARDWAREID, NULL, NULL, 0, &requiredLength);

hardwareID = (wchar_t*)(new char[requiredLength]());

// Second call to populate hardwareID
SetupDiGetDeviceRegistryProperty(deviceInfoList, &deviceInfoData, SPDRP_HARDWAREID, NULL, (PBYTE)hardwareID, requiredLength, NULL);

// Display the string
qDebug() << "hardwareID =" << QString::fromWCharArray(hardwareID);

This will give you a string like USB\ROOT_HUB20&VID1002&PID4396&REV0000 which you can parse.

*Note: not all devices will have a VID and PID, such as non-USB devices.

Answer 3

After this line:

SP_DEVICE_INTERFACE_DETAIL_DATA *pDetData = NULL;

Add this:

DWORD dwDetDataSize = sizeof (SP_DEVICE_INTERFACE_DETAIL_DATA) + 256;
pDetData = (_SP_DEVICE_INTERFACE_DETAIL_DATA_A*) malloc (dwDetDataSize);
pDetData->cbSize = sizeof (SP_DEVICE_INTERFACE_DETAIL_DATA);

After this line:

qDebug ()<<pDetData->DevicePath;

Add this:

free(pDetData);

But eventually you're going to have to read the docs for SetupDiGetDeviceInterfaceDetail(). Do it, there are lots of functions that work like this, with pointers to variable-size structs.

-------- Edited to add: --------

You're really going about this the wrong way. I see you're following the advice you got here, and it's taken you down the wrong path. idVendor and idProduct can only be found in the USB_DEVICE_DESCRIPTOR (MSDN).

It looks like you already know how to get the device handle (using CreateFile()). After that, you call WinUsb_Initialize() (MSDN). That gets you a WINUSB_INTERFACE_HANDLE.

Once you have that handle, you want to call WinUsb_GetDescriptor() (MSDN), with the DescriptorType set to URB_FUNCTION_GET_DESCRIPTOR_FROM_DEVICE. I can't test code now, but it will look something like this:

USB_DEVICE_DESCRIPTOR udd;
memset(&udd, 0, sizeof(udd));
ULONG LengthTransferred = 0;

WinUsb_GetDescriptor(
    winusb_interface_handle, // returned by WinUsbInitialize
    URB_FUNCTION_GET_DESCRIPTOR_FROM_DEVICE,
    0,     // not sure if we need this
    0x409, // not sure if we need this
    &udd,
    sizeof(udd),
    &LengthTransferred);

After that, udd->idVendor and udd->idProduct should have what you want.

Microsoft used to supply sample code for all this in the DDK, and probably still does, but I don't have access to one.

---------- Edited to add: ----------

Daniel K writes that the code should really be:

USB_DEVICE_DESCRIPTOR udd;
memset(&udd, 0, sizeof(udd));
ULONG LengthTransferred = 0;

WinUsb_GetDescriptor(
    winusb_interface_handle,    // returned by WinUsbInitialize
    USB_DEVICE_DESCRIPTOR_TYPE, // Daniel K's suggestion
    0,
    0x409,     // asks for English
    &udd,
    sizeof(udd),
    &LengthTransferred);

See the comments for further details.