Basic constructor.

Construct this object optionally connecting.

Note

Do not use this constructor in derived classes.

Parameters

connect	Call connect on initialization
frequency_rx	frequency in Hz (default: 48000)
channel_count_rx	channel number (1 or 2) (default: 1)
frequency_tx	frequency in Hz (default: 8000)
channel_count_tx	channel number (1 or 2) (default: 1)
buffer_ms	time audio can be buffered without overflowing in milliseconds
vendor_id	Your vendor_id
product_id	Your product_id
product_release	Your product_release

Fully featured constructor.

Construct this object with the supplied USBPhy and parameters. The user this object is responsible for calling connect() or init().

Note

Derived classes must use this constructor and call init() or connect() themselves. Derived classes should also call deinit() in their destructor. This ensures that no interrupts can occur when the object is partially constructed or destroyed.

Parameters

phy	USB phy to use
frequency_rx	frequency in Hz (default: 48000)
channel_count_rx	channel number (1 or 2) (default: 1)
frequency_tx	frequency in Hz (default: 8000)
channel_count_tx	channel number (1 or 2) (default: 1)
buffer_ms	time audio can be buffered without overflowing in milliseconds
vendor_id	Your vendor_id
product_id	Your product_id
product_release	Your product_release

Destroy this object.

Any classes which inherit from this class must call deinit before this destructor runs.

Assert that the current thread of execution holds the lock.

Attach a Callback to update the volume.

Parameters

cb	Callback to attach

attach a Callback to Rx Done

Parameters

cb	Callback to attach

attach a Callback to Tx Done

Parameters

cb	Callback to attach

Called by USBDevice layer on power state change.

Parameters

powered

true if device is powered, false otherwise

Warning: Called in ISR context

Definition at line 342 of file USBDevice.h.

Called by USBDevice on Endpoint0 request.

This is used to handle extensions to standard requests and class specific requests. The function complete_request must be always be called in response to this callback.

Warning: Called in ISR context

Implements USBDevice.

Called by USBDevice on data stage completion.

The function complete_request_xfer_done must be always be called in response to this callback.

Parameters

setup	Setup packet of the current request
aborted	false if the operation was aborted, true otherwise

Warning: Called in ISR context

Implements USBDevice.

Called by USBDevice layer on bus reset.

complete_reset must be called after the device is fully reset.

Warning: Called in ISR context

Reimplemented in USBCDC_ECM, USBCDC, and USBTester.

Definition at line 370 of file USBDevice.h.

Called by USBDevice layer on each new USB frame.

Callbacks are enabled and disabled by calling sof_enable and sof_disable.

Parameters

frame_number

The current frame number

Warning: Called in ISR context

Definition at line 357 of file USBDevice.h.

Called when USB changes state.

Parameters

new_state

The new state of the USBDevice

Warning: Called in ISR context

Implements USBDevice.

Called to complete the setup stage of a callback request.

Possible options that can be passed as a result are:

• Receive - Start the data OUT phase of this control transfer
• Send - Start the data IN phase of this control transfer
• Success - Operation was a success so start the status phase
• Failure - Operation failed or is unsupported so send a stall
• PassThrough - Pass on the request for standard processing

Parameters

result	The result of the setup phase.
data	Buffer to send or receive if the result is Send or Receive
size	Size to transfer if the result is Send or Receive

Called to complete the data stage of a callback request.

Parameters

success

true if the operation was successful, false otherwise

Called to complete a set configuration command.

Parameters

success

true if the configuration was set, false otherwise

Called to complete a set interface command.

Parameters

success

true if the interface was set, false otherwise

Check if the device is configured.

Returns

true if configured, false otherwise

Connect USBAudio.

Power down this instance.

Disable interrupts and stop sending events. This method can be used for temporary power-saving; This call can allow USB to be temporarily disabled to permit power saving. However, it is up to the user to make sure all the transfers have concluded (for example when USB power is lost). USBDevice::connect can be used to resume USB operation.

Disconnect USBAudio.

This unblocks all calls to read_ready and write_ready.

Abort the current transfer on this endpoint.

Parameters

endpoint

endpoint with transfer to abort

Note

This endpoint must already have been setup with endpoint_add

Add an endpoint.

Parameters

endpoint	Endpoint to enable
max_packet	Maximum size of a packet which can be sent or received on this endpoint
type	Endpoint type - USB_EP_TYPE_BULK, USB_EP_TYPE_INT or USB_EP_TYPE_ISO
callback	Method pointer to be called when a packet is transferred

Returns

true if successful, false otherwise

Add an endpoint.

Parameters

endpoint	Endpoint to enable
max_packet	Maximum size of a packet which can be sent or received on this endpoint
type	Endpoint type - USB_EP_TYPE_BULK, USB_EP_TYPE_INT or USB_EP_TYPE_ISO
callback	Method pointer to be called when a packet is transferred

Returns

true if successful, false otherwise

Definition at line 162 of file USBDevice.h.

Get the current maximum size for this endpoint.

Return the currently configured maximum packet size, wMaxPacketSize, for this endpoint.

Note

This endpoint must already have been setup with endpoint_add

Remove an endpoint.

Parameters

endpoint

Endpoint to disable

Note

This endpoint must already have been setup with endpoint_add

Remove all non-zero endpoints.

Stall an endpoint.

If there is an ongoing transfer on this endpoint then it will be aborted.

Parameters

endpoint

Endpoint to stall

Note

You cannot stall endpoint 0 with this function

This endpoint must already have been setup with endpoint_add

Get the endpoint table of this device.

Returns

Endpoint table of the USBPhy attached to this USBDevice

Un-stall an endpoint.

Un-stalling an endpoint resets data toggle back to DATA0. Additionally, if there is an ongoing transfer on this endpoint it will be aborted.

Parameters

endpoint

Endpoint to un-stall

Note

This endpoint must already have been setup with endpoint_add

Find a descriptor type inside the configuration descriptor.

Parameters

descriptor_type	Type of descriptor to find
index	Configuration descriptor index ( 0 if only one configuration present )

Returns

A descriptor of the given type or NULL if none were found

Get current volume between 0.0 and 1.0.

Returns

volume

Initialize this instance.

This function must be called before calling any other functions of this class, unless specifically

Acquire exclusive access to this instance USBDevice.

Read audio data.

Parameters

buf	pointer on a buffer which will be filled with audio data
size	size to read

Returns

true if successful

Get the status of a read.

Parameters

endpoint

endpoint to get the status of

Returns

number of bytes read by this endpoint

Nonblocking audio data read.

Read the available audio data.

Parameters

buf	pointer on a buffer which will be filled with audio data
size	size to read
actual	size actually read

Note

This function is safe to call from USBAudio callbacks.

Return the number read packets dropped due to overflow.

Parameters

clear

Reset the overflow count back to 0

Returns

Number of packets dropped due to overflow

Check if the audio read channel is open.

Returns

true if the audio read channel open, false otherwise

start a read on the given endpoint

Start a read on the given endpoint. The data buffer must remain unchanged until the transfer either completes or is aborted.

Parameters

endpoint	endpoint to read data from
buffer	buffer to fill with read data
size	The size of data to read. This must be greater than or equal to the max packet size for this endpoint

Returns

true if the read was completed, otherwise false

Note

This endpoint must already have been setup with endpoint_add

Wait until the audio read channel is open.

Disable the start of frame interrupt.

Stop calling USBDevice::callback_sof.

Enable the start of frame interrupt.

Call USBDevice::callback_sof on every frame.

Callback called to indicate the USB processing needs to be done.

Implements USBPhyEvents.

Release exclusive access to this instance USBDevice.

Write audio data.

Parameters

buf	pointer to audio data to write
size	size to write

Returns

true if successful

Get the status of a write.

Parameters

endpoint

endpoint to get the status of

Returns

number of bytes sent by this endpoint

Nonblocking audio data write.

Write the available audio data.

Parameters

buf	pointer to audio data to write
size	size to write
actual	actual size written

Note

This function is safe to call from USBAudio callbacks.

Check if the audio write channel is open.

Returns

true if the audio write channel open, false otherwise

Write a data to the given endpoint.

Write data to an endpoint. The data sent must remain unchanged until the transfer either completes or is aborted.

Parameters

endpoint	endpoint to write data to
buffer	data to write
size	the size of data to send. This must be less than or equal to the max packet size of this endpoint

Note

This endpoint must already have been setup with endpoint_add

Return the number write packets not sent due to underflow.

Parameters

clear

Reset the underflow count back to 0

Returns

Number of packets that should have been sent but weren't due to overflow

Wait until the audio write channel is open.