PPARALLEL_IEEE_REV_TO_FWD callback function (parallel.h)
The PPARALLEL_IEEE_REV_TO_FWD-typed callback routine changes the transfer mode from reverse to forward. The system-supplied bus driver for parallel ports supplies this routine.
Syntax
PPARALLEL_IEEE_REV_TO_FWD PparallelIeeeRevToFwd;
NTSTATUS PparallelIeeeRevToFwd(
[in] PVOID Context
)
{...}
Parameters
[in] Context
Pointer to a device extension of a parallel device's physical device object (PDO).
Return value
| Return code | Description |
|---|---|
|
The transfer mode was changed from reverse to forward. |
|
An internal operation resulted in an NTSTATUS error. |
Remarks
To obtain a pointer to the system-supplied PPARALLEL_IEEE_REV_TO_FWD callback, a kernel-mode driver uses an IOCTL_INTERNAL_PARCLASS_CONNECT request, which returns a PARCLASS_INFORMATION structure. The IeeeRevToFwdMode member of the PARCLASS_INFORMATION structure is a pointer to this callback.
If the device is connected and is in the forward mode, the PPARALLEL_IEEE_REV_TO_FWD callback returns without further processing. Otherwise, the PPARALLEL_IEEE_REV_TO_FWD callback puts a parallel device in the forward mode and connects a previously negotiated forward protocol. The PNEGOTIATE_IEEE_MODE callback can be used to negotiate a forward protocol.
The PPARALLEL_IEEE_REV_TO_FWD callback runs in the caller's thread at the IRQL of the caller.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | parallel.h (include Parallel.h) |