3.3.4.14 USB_HOST_AUDIO_V1_FeatureUnitChannelVolumeRangeGet Function

C

USB_HOST_AUDIO_V1_RESULT USB_HOST_AUDIO_V1_FeatureUnitChannelVolumeRangeGet(
    USB_HOST_AUDIO_V1_OBJ audioObj, 
    USB_HOST_AUDIO_V1_CONTROL_ENTITY_OBJ entityObject, 
    USB_HOST_AUDIO_V1_REQUEST_HANDLE * requestHandle, 
    uint8_t channelNumber, 
    void * data, 
    size_t size
);

Description

This function schedules a control request to the Audio Device feature unit to get the range supported by the volume control on the specified channel.

Prior to calling this function the user should call the USB_HOST_AUDIO_V1_FeatureUnitChannelVolumeSubRangeNumbersGet function to know how many sub-ranges are supported.

Users should calculate the 'size' parameter of this function, as follows:

size = Size of
        number of ranges + nSubRanges * (Size (MIN) + Size (MAX) + Size of (RES))

If the request was scheduled successfully, the requestHandle parameter will contain a request handle that uniquely identifies this request. If the request could not be scheduled successfully, requestHandle will contain USB_HOST_AUDIO_V1_REQUEST_HANDLE_INVALID.

When the control request completes, the Audio v1.0 Client Driver will call the callback function that was set using the USB_HOST_AUDIO_V1_EntityRequestCallbackSet function. The context parameter specified here will be returned in the callback.

Parameters

Returns

Remarks

None.