Struct UacHandler 

pub struct UacHandler<'d, A: UsbHostAllocator<'d>> {
    pub interface_collection: AudioInterfaceCollection,
    pub control_channel: A::Pipe<Control, InOut>,
    pub output_channel: Option<A::Pipe<Isochronous, Out>>,
    pub feedback_channel: Option<A::Pipe<Isochronous, In>>,
    /* private fields */
}

Handler for USB Audio Class (UAC) devices, providing control and streaming functionality.

This struct manages the USB pipes and interface descriptors required to interact with a UAC device, including control, output, and feedback pipes.

Fields

interface_collection: AudioInterfaceCollection

Collection of audio interface descriptors parsed from the device configuration.

control_channel: A::Pipe<Control, InOut>

Control pipe for sending standard and class-specific requests.

output_channel: Option<A::Pipe<Isochronous, Out>>

Output pipe for isochronous audio streaming (if available).

feedback_channel: Option<A::Pipe<Isochronous, In>>

Feedback pipe for isochronous feedback endpoint (if available).

Implementations

impl<'d, A: UsbHostAllocator<'d>> UacHandler<'d, A>

pub async fn try_register( alloc: &A, enum_info: EnumerationInfo, ) -> Result<Self, RegisterError>

Attempts to register a UAC device and allocate necessary pipes.

This method parses the device’s configuration, finds a suitable streaming interface, and allocates output and feedback pipes as needed.

Returns a new UacHandler on success, or a RegisterError if registration fails.

pub async fn output(&mut self) -> Result<UacOut<'d, A>, RequestError>

Returns a UacOut object for audio output streaming.

Returns an error if the output or feedback pipe is not allocated or if the interface is unsupported.

pub fn input_terminal(&self) -> &TerminalDescriptor

Returns a reference to the input terminal descriptor associated with this handler.

pub fn output_interface(&self) -> &AudioStreamingInterface

Returns a reference to the output audio streaming interface descriptor.

pub async fn get_sampling_freq( &mut self, terminal_id: u8, ) -> Result<u32, RequestError>

Retrieves the current sampling frequency from the specified terminal entity.

Returns the sampling frequency in Hz, or an error if the request fails.

pub async fn get_supported_language(&mut self) -> Result<u16, RequestError>

Retrieves the supported language ID from the device.

Returns the language ID as a 16-bit value, or an error if the request fails.

pub async fn get_string( &mut self, index: StringIndex, lang_id: u16, ) -> Result<String<MAX_STRING_LENGTH>, RequestError>

Retrieves a string descriptor from the device.

Arguments

• index - The string descriptor index
• lang_id - The language ID for the string

Returns the string as a UTF-8 encoded string, or an error if the request fails.

pub async fn get_curr_entity1( &mut self, control_selector: u16, channel: u8, entity: u8, interface: u8, ) -> Result<u8, RequestError>

Retrieves a 1-byte current value from a UAC entity.

Arguments

• control_selector - The control selector (e.g., volume, mute)
• channel - The channel number (0 for master control)
• entity - The entity ID
• interface - The interface number

Returns the current value as a u8, or an error if the request fails.

pub async fn get_curr_entity2( &mut self, control_selector: u16, channel: u8, entity: u8, interface: u8, ) -> Result<u16, RequestError>

Retrieves a 2-byte current value from a UAC entity.

Arguments

• control_selector - The control selector (e.g., volume, mute)
• channel - The channel number (0 for master control)
• entity - The entity ID
• interface - The interface number

Returns the current value as a u16, or an error if the request fails.

pub async fn get_curr_entity3( &mut self, control_selector: u16, channel: u8, entity: u8, interface: u8, ) -> Result<u32, RequestError>

Retrieves a 4-byte current value from a UAC entity.

Arguments

• control_selector - The control selector (e.g., sampling frequency)
• channel - The channel number (0 for master control)
• entity - The entity ID
• interface - The interface number

Returns the current value as a u32, or an error if the request fails.

pub async fn get_range_entity1( &mut self, control_selector: u16, channel: u8, entity: u8, interface: u8, ) -> Result<Layout1ParameterBlock, RequestError>

Retrieves the range of supported 1-byte values from a UAC entity.

Arguments

• control_selector - The control selector (e.g., volume, mute)
• channel - The channel number (0 for master control)
• entity - The entity ID
• interface - The interface number

Returns a Layout1ParameterBlock containing the supported ranges, or an error if the request fails.

pub async fn get_range_entity2( &mut self, control_selector: u16, channel: u8, entity: u8, interface: u8, ) -> Result<Layout2ParameterBlock, RequestError>

Retrieves the range of supported 2-byte values from a UAC entity.

Arguments

• control_selector - The control selector (e.g., volume, mute)
• channel - The channel number (0 for master control)
• entity - The entity ID
• interface - The interface number

Returns a Layout2ParameterBlock containing the supported ranges, or an error if the request fails.

pub async fn get_range_entity3( &mut self, control_selector: u16, channel: u8, entity: u8, interface: u8, ) -> Result<Layout3ParameterBlock, RequestError>

Retrieves the range of supported 4-byte values from a UAC entity.

Arguments

• control_selector - The control selector (e.g., sampling frequency)
• channel - The channel number (0 for master control)
• entity - The entity ID
• interface - The interface number

Returns a Layout3ParameterBlock containing the supported ranges, or an error if the request fails.