1.1.5.2.1 DRV_I2S_Open Function
DRV_HANDLE DRV_I2S_Open ( const SYS_MODULE_INDEX index, const DRV_IO_INTENT ioIntent )
Summary
Opens the specified I2S driver instance and returns a handle to it.
Description
This routine opens the specified I2S driver instance and provides a handle that must be provided to all other client-level operations to identify the caller and the instance of the driver. The ioIntent parameter defines how the client interacts with this driver instance.
Specifying a DRV_IO_INTENT_EXCLUSIVE will cause the driver to provide exclusive access to this client. The driver cannot be opened by any other client.
Preconditions
Function DRV_I2S_Initialize must have been called before calling this function.
Parameters
| Parameters | Description |
|---|---|
| index | Identifier for the object instance to be opened |
| intent | Zero or more of the values from the enumeration DRV_IO_INTENT "ORed" together to indicate the intended useof the driver. See function description for details. |
Returns
If successful, the routine returns a valid open-instance handle (a number identifying both the caller and the module instance).
If an error occurs, the return value is DRV_HANDLE_INVALID. Error can occur
if the number of client objects allocated via DRV_I2S_CLIENTS_NUMBER is insufficient.
if the client is trying to open the driver but driver has been opened exclusively by another client.
if the driver peripheral instance being opened is not initialized or is invalid.
if the client is trying to open the driver exclusively, but has already been opened in a non exclusive mode by another client.
if the driver is not ready to be opened, typically when the initialize routine has not completed execution.
Remarks
The handle returned is valid until the DRV_I2S_Close routine is called. This routine will NEVER block waiting for hardware. If the requested intent flags are not supported, the routine will return DRV_HANDLE_INVALID. This function is thread safe in a RTOS application.
Example
DRV_HANDLE handle; handle = DRV_I2S_Open(DRV_I2S_INDEX_0, DRV_IO_INTENT_EXCLUSIVE); if (DRV_HANDLE_INVALID == handle) {
_// Unable to open the driver_
_// May be the driver is not initialized or the initialization_ _// is not complete._
}C
DRV_HANDLE DRV_I2S_Open(const SYS_MODULE_INDEX index, const DRV_IO_INTENT ioIntent);