DRV_AT25DF_Open Function

C

DRV_HANDLE DRV_AT25DF_Open
(
    const SYS_MODULE_INDEX drvIndex,
    const DRV_IO_INTENT ioIntent
)

Summary

Opens the specified AT25DF driver instance and returns a handle to it.

Description

This routine opens the specified AT25DF 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.

This driver is a single client driver, so DRV_AT25DF_Open API should be called only once until driver is closed.

Precondition

Function DRV_AT25DF_Initialize must have been called before calling this function.

Parameters

ParametersDescription
drvIndexIdentifier for the object instance to be opened.
ioIntentZero or more of the values from the enumeration DRV_IO_INTENT "ORed" together to indicate the intended use of the driver.

Note: This driver ignores the ioIntent argument.

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 driver has been already opened once and in use
  • if the driver instance being opened is not initialized or is invalid

Example

DRV_HANDLE handle;

handle = DRV_AT25DF_Open(DRV_AT25DF_INDEX, DRV_IO_INTENT_READWRITE);
if (handle == DRV_HANDLE_INVALID)
{
    // Unable to open the driver
    // May be the driver is not initialized
}

Remarks

The handle returned is valid until the DRV_AT25DF_Close routine is called.