nRF52840 only: Module with types, definitions, and API used by USB Audio class. More...

Modules
	USB Audio descriptors
	nRF52840 only: Descriptors used in the USB Audio class.

	USB Audio internals
	nRF52840 only: USB Audio class internals.

	USB Audio types
	nRF52840 only: Type definitions for the USB Audio class.

	USB AUDIO class configuration

Data Structures
struct	app_usbd_audio_t
	Audio class instance type. More...

Macros
#define	APP_USBD_AUDIO_GLOBAL_DEF (instance_name,interfaces_configs,user_ev_handler,format_descriptor,input_descriptor,output_descriptor,feature_descriptor,delay,format,ep_size,type_str,terminal_link)
	Global definition of app_usbd_audio_t class instance. More...

#define	APP_USBD_AUDIO_FORMAT_DESCRIPTOR (name,...)
	Initializer of Audio Format descriptor. More...

#define	APP_USBD_AUDIO_INPUT_DESCRIPTOR (name,...)
	Initializer of Audio Input descriptor. More...

#define	APP_USBD_AUDIO_OUTPUT_DESCRIPTOR (name,...)
	Initializer of Audio Output descriptor. More...

#define	APP_USBD_AUDIO_FEATURE_DESCRIPTOR (name,...)
	Initializer of Feture Output descriptor. More...

Typedefs
typedef enum app_usbd_audio_user_event_e	app_usbd_audio_user_event_t
	Events passed to user event handler. More...

Enumerations
enum	app_usbd_audio_user_event_e { APP_USBD_AUDIO_USER_EVT_CLASS_REQ , APP_USBD_AUDIO_USER_EVT_RX_DONE , APP_USBD_AUDIO_USER_EVT_TX_DONE }
	Events passed to user event handler. More...

Functions
static app_usbd_class_inst_t const *	app_usbd_audio_class_inst_get ( app_usbd_audio_t const *p_audio)

static app_usbd_audio_req_t *	app_usbd_audio_class_request_get ( app_usbd_audio_t const *p_audio)
	Helper function to get audio specific request from audio class. More...

static app_usbd_audio_t const *	app_usbd_audio_class_get ( app_usbd_class_inst_t const *p_inst)
	Helper function to get audio from base class instance. More...

size_t	app_usbd_audio_class_rx_size_get ( app_usbd_class_inst_t const *p_inst)
	Get the size of last received transfer. More...

ret_code_t	app_usbd_audio_class_rx_start ( app_usbd_class_inst_t const p_inst, void p_buff, size_t size)
	Start audio data copying from the endpoint buffer. More...

ret_code_t	app_usbd_audio_class_tx_start ( app_usbd_class_inst_t const p_inst, const void p_buff, size_t size)
	Start copying audio data to the endpoint buffer. More...

ret_code_t	app_usbd_audio_sof_interrupt_register ( app_usbd_class_inst_t const *p_inst, app_usbd_sof_interrupt_handler_t handler)
	Register audio instance as the one that requires SOF events in interrupt. More...

Detailed Description

nRF52840 only: Module with types, definitions, and API used by USB Audio class.

Reference specifications:

"Universal Serial Bus Device Class Definition for Audio Devices" Release 1.0, March 18, 1998.
"Universal Serial Bus Device Class Definition for Audio Data Formats" Release 1.0, March 18, 1998.
"Universal Serial Bus Device Class Definition for Terminal Types" Release 1.0, March 18, 1998.

Macro Definition Documentation

#define APP_USBD_AUDIO_FEATURE_DESCRIPTOR	(	name,
		...
	)

Value:

         
          static
         
         uint8_t
         
          const
         
          CONCAT_2
         
         (name,  _data)[] =             \
        
         {                                                           \
        
         __VA_ARGS__                                             \
        
         };                                                          \
        
         static
         
          const
         
          app_usbd_audio_subclass_desc_t
         
         name =          \
        
         {                                                           \
        
         sizeof(
         
          CONCAT_2
         
         (name, _data)),                          \
        
         APP_USBD_AUDIO_AC_IFACE_SUBTYPE_FEATURE_UNIT,
         
          \
         
          CONCAT_2
         
         (name,_data)                                    \
        
         }

Initializer of Feture Output descriptor.

Parameters

name	Feture descriptor name.
...	Feture descriptor data.

#define APP_USBD_AUDIO_FORMAT_DESCRIPTOR	(	name,
		...
	)

Value:

         
          static
         
         uint8_t
         
          const
         
          CONCAT_2
         
         (name,  _data)[] =             \
        
         {                                                           \
        
         __VA_ARGS__                                             \
        
         };                                                          \
        
         static
         
          const
         
          app_usbd_audio_subclass_desc_t
         
         name =          \
        
         {                                                           \
        
         sizeof(
         
          CONCAT_2
         
         (name, _data)),                          \
        
         APP_USBD_AUDIO_AS_IFACE_SUBTYPE_FORMAT_TYPE,
         
          \
         
          CONCAT_2
         
         (name,_data)                                    \
        
         }

Initializer of Audio Format descriptor.

Parameters

name	Format descriptor name.
...	Format descriptor data.

#define APP_USBD_AUDIO_GLOBAL_DEF	(	instance_name,
		interfaces_configs,
		user_ev_handler,
		format_descriptor,
		input_descriptor,
		output_descriptor,
		feature_descriptor,
		delay,
		format,
		ep_size,
		type_str,
		terminal_link
	)

Value:

         
          APP_USBD_AUDIO_GLOBAL_DEF_INTERNAL
         
         (instance_name,       \
        
         interfaces_configs,  \
        
         user_ev_handler,     \
        
         format_descriptor,   \
        
         input_descriptor,    \
        
         output_descriptor,   \
        
         feature_descriptor,  \
        
         delay,               \
        
         format,              \
        
         ep_size,             \
        
         type_str,            \
        
         terminal_link)

Global definition of app_usbd_audio_t class instance.

Parameters

instance_name	Name of global instance.
interfaces_configs	Interfaces configurations.
user_ev_handler	User event handler.
format_descriptor	Audio class Format descriptor.
input_descriptor	Audio class Input Terminal descriptor.
output_descriptor	Audio class Output Terminal descriptor.
feature_descriptor	Audio class Feature Unit descriptor.
delay	Streaming delay.
format	FormatTag ( app_usbd_audio_as_iface_format_tag_t ).
ep_size	Endpoint size.
type_str	Streaming type MIDISTREAMING/AUDIOSTREAMING.
terminal_link	Terminal link in AS Interface Descriptor.

Note: This macro is just simplified version of APP_USBD_AUDIO_GLOBAL_DEF_INTERNAL

#define APP_USBD_AUDIO_INPUT_DESCRIPTOR	(	name,
		...
	)

Value:

         
          static
         
         uint8_t
         
          const
         
          CONCAT_2
         
         (name,  _data)[] =             \
        
         {                                                           \
        
         __VA_ARGS__                                             \
        
         };                                                          \
        
         static
         
          const
         
          app_usbd_audio_subclass_desc_t
         
         name =          \
        
         {                                                           \
        
         sizeof(
         
          CONCAT_2
         
         (name, _data)),                          \
        
         APP_USBD_AUDIO_AC_IFACE_SUBTYPE_INPUT_TERMINAL,
         
          \
         
          CONCAT_2
         
         (name,_data)                                    \
        
         }

Initializer of Audio Input descriptor.

Parameters

name	Input descriptor name.
...	Input descriptor data.

#define APP_USBD_AUDIO_OUTPUT_DESCRIPTOR	(	name,
		...
	)

Value:

         
          static
         
         uint8_t
         
          const
         
          CONCAT_2
         
         (name,  _data)[] =             \
        
         {                                                           \
        
         __VA_ARGS__                                             \
        
         };                                                          \
        
         static
         
          const
         
          app_usbd_audio_subclass_desc_t
         
         name =          \
        
         {                                                           \
        
         sizeof(
         
          CONCAT_2
         
         (name, _data)),                          \
        
         APP_USBD_AUDIO_AC_IFACE_SUBTYPE_OUTPUT_TERMINAL,
         
          \
         
          CONCAT_2
         
         (name,_data)                                    \
        
         }

Initializer of Audio Output descriptor.

Parameters

name	Output descriptor name.
...	Output descriptor data.

Typedef Documentation

typedef enum app_usbd_audio_user_event_e app_usbd_audio_user_event_t

Events passed to user event handler.

Note: Example prototype of user event handler:

void audio_user_ev_handler( app_usbd_class_inst_t const * p_inst,

app_usbd_audio_user_event_t event);

Enumeration Type Documentation

enum app_usbd_audio_user_event_e

Events passed to user event handler.

Note: Example prototype of user event handler:

void audio_user_ev_handler( app_usbd_class_inst_t const * p_inst,

app_usbd_audio_user_event_t event);

Enumerator
APP_USBD_AUDIO_USER_EVT_CLASS_REQ	User event CLASS_REQ
APP_USBD_AUDIO_USER_EVT_RX_DONE	User event RX_DONE
APP_USBD_AUDIO_USER_EVT_TX_DONE	User event TX_DONE

Function Documentation

static app_usbd_audio_t const* app_usbd_audio_class_get ( app_usbd_class_inst_t const * p_inst )

inline static

Helper function to get audio from base class instance.

Parameters

[in] p_inst Base class instance.

Returns: Audio class handle.

static app_usbd_class_inst_t const* app_usbd_audio_class_inst_get ( app_usbd_audio_t const * p_audio )

inline static

@brief Helper function to get class instance from Audio class.

Parameters

[in] p_audio Audio class instance (declared by APP_USBD_AUDIO_GLOBAL_DEF ).

Returns: Base class instance.

static app_usbd_audio_req_t * app_usbd_audio_class_request_get ( app_usbd_audio_t const * p_audio )

inline static

Helper function to get audio specific request from audio class.

Parameters

[in] p_audio Audio class instance (declared by APP_USBD_AUDIO_GLOBAL_DEF ).

Returns: Audio class specific request.

size_t app_usbd_audio_class_rx_size_get ( app_usbd_class_inst_t const * p_inst )

Get the size of last received transfer.

Note: Call this function in reaction to a SOF event to check if there is any data to process.

Parameters

p_inst Base class instance.

Returns: Number of bytes received in the last transmission.

ret_code_t app_usbd_audio_class_rx_start	(	app_usbd_class_inst_t const *	p_inst ,
		void *	p_buff ,
		size_t	size
	)

Start audio data copying from the endpoint buffer.

Function to be used to copy data from an audio OUT endpoint to a given buffer. When it finishes, an APP_USBD_AUDIO_USER_EVT_RX_DONE event is generated.

Parameters

p_inst	Base class instance.
p_buff	Target buffer.
size	Size of the requested data.

Returns: Result of the endpoint transmission start.

See Also: app_usbd_audio_class_rx_size_get

Note: This function should be called in reaction to a SOF event. Isochronous endpoints are double buffered and they are automatically switched at every SOF.

ret_code_t app_usbd_audio_class_tx_start	(	app_usbd_class_inst_t const *	p_inst ,
		const void *	p_buff ,
		size_t	size
	)

Start copying audio data to the endpoint buffer.

Function to be used to copy data to an audio IN endpoint from a given buffer. When it finishes, an APP_USBD_AUDIO_USER_EVT_TX_DONE event is generated.

Parameters

p_inst	Base class instance.
p_buff	Source buffer.
size	Size of the data to be sent.

Returns: Result of the endpoint transsmision start.

Note: This function should be called in reaction to a SOF event. Isochronous endpoints are double buffered and they are automatically switched at every SOF.

ret_code_t app_usbd_audio_sof_interrupt_register	(	app_usbd_class_inst_t const *	p_inst ,
		app_usbd_sof_interrupt_handler_t	handler
	)

Register audio instance as the one that requires SOF events in interrupt.

This function should be called before appending the instance.

Parameters

p_inst	Audio instance that requires SOF event.
handler	Handler to SOF event

Return values

NRF_SUCCESS Instance linked into SOF processing list.

See Also: app_usbd_class_sof_interrupt_register

Modules

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Enumeration Type Documentation

Function Documentation