This function returns information about the first attached device on the specified bus. The USB_HOST_DeviceGetNext() function can be used to get the reference to the next attached device on the bus. The USB_HOST_DEVICE_INFO object is provided by the application.The device information will be populated into this object. If there are no devices attached on the bus, the function will set the deviceObjHandle parameter, in the USB_HOST_DEVICE_INFO object, to USB_HOST_DEVICE_OBJ_HANDLE INVALID.

USB_HOST_RESULT USB_HOST_DeviceGetFirst(
    USB_HOST_BUS bus, 
    USB_HOST_DEVICE_INFO * deviceInfo
);

The USB_HOST_BusEnable function should have been called to enable detection of attached devices.

USB_HOST_RESULT_SUCCESS - The function executed successfully. USB_HOST_RESULT_END_OF_DEVICE_LIST - There are no attached devices on the bus. USB_HOST_RESULT_BUS_UNKNOWN - The specified bus does not exist in the system. USB_HOST_RESULT_BUS_NOT_ENABLED - The specified bus is not enabled. USB_HOST_RESULT_PARAMETER_INVALID - the deviceInfo parameter is NULL. USB_HOST_RESULT_FAILURE - an unknown failure occurred.

None.