1.1.5.5.2 DRV_I2S_BUFFER_EVENT_HANDLER Type
Pointer to a I2S Driver Buffer Event handler function
Description
I2S Driver Buffer Event Handler Function Pointer
This data type defines the required function signature for the I2S driver buffer event handling callback function. A client must register a pointer using the buffer event handling function whose function signature (parameter and return value types) match the types specified by this function pointer in order to receive buffer related event calls back from the driver.
The parameters and return values are described here and a partial example implementation is provided.
Parameters
| Parameters | Description |
|---|---|
| event | Identifies the type of event |
| bufferHandle | Handle identifying the buffer to which the vent relates |
| context | Value identifying the context of the application that registered the event handling function. |
Returns
None.
Remarks
If the event is DRV_I2S_BUFFER_EVENT_COMPLETE, it means that the data was transferred successfully.
If the event is DRV_I2S_BUFFER_EVENT_ERROR, it means that the data was not transferred successfully. The DRV_I2S_BufferCompletedBytesGet function can be called to find out how many bytes were processed.
The bufferHandle parameter contains the buffer handle of the buffer that associated with the event. And bufferHandle will be valid while the buffer request is in the queue and during callback, unless an error occurred. After callback returns, the driver will retire the buffer handle.
The context parameter contains the a handle to the client context, provided at the time the event handling function was registered using the DRV_I2S_BufferEventHandlerSet function. This context handle value is passed back to the client as the "context" parameter. It can be any value necessary to identify the client context or instance (such as a pointer to the client's data) instance of the client that made the buffer add request.
The event handler function executes in the peripheral's interrupt context when the driver is configured for interrupt mode operation. It is recommended of the application to not perform process intensive or blocking operations with in this function.
The DRV_I2S_ReadBufferAdd and DRV_I2S_WriteBufferAdd functions can be called in the event handler to add a buffer to the driver queue. These functions can only be called to add buffers to the driver whose event handler is running. For example, I2S2 driver buffers cannot be added in I2S1 driver event handler.
Example
void APP_MyBufferEventHandler( DRV_I2S_BUFFER_EVENT event, DRV_I2S_BUFFER_HANDLE bufferHandle, uintptr_t context ) {
MY_APP_DATA_STRUCT pAppData = (MY_APP_DATA_STRUCT) context; switch(event) { case DRV_I2S_BUFFER_EVENT_COMPLETE: _// Handle the completed buffer._
break; case DRV_I2S_BUFFER_EVENT_ERROR:
default: _// Handle error._
break;
Files
}
}C
typedef void (* DRV_I2S_BUFFER_EVENT_HANDLER)(DRV_I2S_BUFFER_EVENT event, DRV_I2S_BUFFER_HANDLE bufferHandle, uintptr_t context);