PPARALLEL_IEEE_FWD_TO_REV callback function (parallel.h)
The PPARALLEL_IEEE_FWD_TO_REV-typed callback routine changes the transfer mode from forward to reverse. The system-supplied bus driver for parallel ports supplies this routine.
Syntax
PPARALLEL_IEEE_FWD_TO_REV PparallelIeeeFwdToRev;
NTSTATUS PparallelIeeeFwdToRev(
[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 forward to reverse. |
|
An internal operation resulted in an NTSTATUS error. |
Remarks
To obtain a pointer to the system-supplied PPARALLEL_IEEE_FWD_TO_REV callback, a kernel-mode driver uses an IOCTL_INTERNAL_PARCLASS_CONNECT request, which returns a PARCLASS_INFORMATION structure. The IeeeFwdToRevMode member of the PARCLASS_INFORMATION structure is a pointer to this callback.
If the device is connected and in the reverse mode, the PPARALLEL_IEEE_FWD_TO_REV callback returns without further processing. Otherwise, the callback puts the parallel device into reverse mode and connects a previously negotiated reverse protocol. The PNEGOTIATE_IEEE_MODE callback can be used to negotiate the reverse protocol.
The PPARALLEL_IEEE_FWD_TO_REV callback runs in the caller's thread at the caller's IRQL.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | parallel.h (include Parallel.h) |