SerCx2CustomReceiveCreate function (sercx.h)
The SerCx2CustomReceiveCreate method creates a custom-receive object, which version 2 of the serial framework extension (SerCx2) uses to read receive data from the serial controller by means of a custom data-transfer mechanism.
Syntax
NTSTATUS SerCx2CustomReceiveCreate(
[in] WDFDEVICE Device,
[in] PSERCX2_CUSTOM_RECEIVE_CONFIG CustomReceiveConfig,
[in] PWDF_OBJECT_ATTRIBUTES Attributes,
[out] SERCX2CUSTOMRECEIVE *CustomReceive
);
Parameters
[in] Device
A WDFDEVICE handle to the framework device object that represents the serial controller. The serial controller driver created this object in its EvtDriverDeviceAdd callback function. For more information, see SerCx2InitializeDevice.
[in] CustomReceiveConfig
A pointer to a SERCX2_CUSTOM_RECEIVE_CONFIG structure. Before calling this method, the caller must call the SERCX2_CUSTOM_RECEIVE_CONFIG_INIT function to initialize the structure. This structure contains pointers to a set of event callback routines that are implemented by the serial controller driver. SerCx2 calls these functions to perform custom-receive transactions.
[in] Attributes
A pointer to a WDF_OBJECT_ATTRIBUTES structure that describes the attributes to assign to the new custom-receive object. Before calling this method, the caller must call the WDF_OBJECT_ATTRIBUTES_INIT function to initialize the structure. This parameter is optional and can be specified as WDF_NO_OBJECT_ATTRIBUTES if the serial controller driver does not need to assign attributes to the object. For more information, see Remarks.
[out] CustomReceive
A pointer to a location to which this method writes a SERCX2CUSTOMRECEIVE handle to the newly created custom-receive object. SerCx2 and the serial controller driver use this handle in subsequent calls to refer to this object.
Return value
This method returns STATUS_SUCCESS if the call is successful. Possible error return values include the following status codes.
Return code | Description |
---|---|
|
A custom-receive object already exists from a previous SerCx2CustomReceiveCreate call; or a system-DMA-receive object exists from a previous SerCx2CustomReceiveCreate call; or a system-DMA-transmit object exists from a previous SerCx2CustomTransmitCreate call; or SerCx2PioReceiveCreate has not yet been called to create a PIO-receive object. |
|
A parameter value is not valid. |
|
The Config->Size value does not equal sizeof(SERCX2_CUSTOM_RECEIVE_CONFIG). |
|
Insufficient resources are available to create the custom-receive object. |
Remarks
This method is called by the serial controller driver to create a custom-receive object. SerCx2 uses this object to do custom-receive transactions, which are transactions that use a custom data-transfer mechanism to read data received by the serial controller.
A serial controller driver must successfully call the SerCx2InitializeDevice and SerCx2PioReceiveCreate methods before calling SerCx2CustomReceiveCreate.
Before calling SerCx2CustomReceiveCreate, the serial controller driver must call the SERCX2_CUSTOM_RECEIVE_CONFIG_INIT function to initialize the SERCX2_CUSTOM_RECEIVE_CONFIG structure pointed to by CustomReceiveConfig. This function sets the following members of the structure to zero:
- Alignment
- MinimumTransactionLength
- MaximumTransactionLength
- MinimumTransferUnit
- Exclusive
- If Alignment is zero, SerCx2 sets the data alignment value to one, which means the read buffer can start on an arbitrary byte boundary in memory.
- If MinimumTransactionLength is zero, SerCx2 sets the minimum transaction length to one byte.
- If MaximumTransactionLength is zero, SerCx2 sets the maximum transaction length to ((ULONG)-1).
- If MinimumTransferUnit is zero, SerCx2 sets the minimum transfer unit to one byte.
- If Exclusive is zero (FALSE), exclusive mode is disabled.
As an option, a serial controller driver can use the Attributes parameter to create a context for the custom-receive object, and to supply pointers to EvtCleanupCallback and EvtDestroyCallback functions that are called to prepare the object for deletion. For more information, see WDF_OBJECT_ATTRIBUTES.
If the Attributes parameter points to a WDF_OBJECT_ATTRIBUTES structure, the caller must not overwrite the values that the WDF_OBJECT_ATTRIBUTES_INIT initialization function writes to the ParentObject, ExecutionLevel, and SynchronizationScope members of this structure.
For more information about creating custom-receive objects, see SERCX2CUSTOMRECEIVE. For more information about custom-receive transactions, see SerCx2 Custom-Receive Transactions.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Available starting with Windows 8.1. |
Target Platform | Universal |
Header | sercx.h |
IRQL | PASSIVE_LEVEL |