PI8042_SYNCH_READ_PORT callback function (ntdd8042.h)
The PI8042_SYNCH_READ_PORT-typed callback routine does a synchronized read from an i8042 port. I8042prt supplies this callback.
Syntax
PI8042_SYNCH_READ_PORT Pi8042SynchReadPort;
NTSTATUS Pi8042SynchReadPort(
[in] PVOID Context,
[out] PUCHAR Value,
[in] BOOLEAN WaitForACK
)
{...}
Parameters
[in] Context
Pointer to a context supplied by I8042prt.
[out] Value
Pointer to the UCHAR value returned by the routine.
[in] WaitForACK
Not used.
Return value
The PI8042_SYNCH_READ_PORT callback returns one of the following status values:
Return code | Description |
---|---|
|
The routine successfully returned a byte. |
|
The hardware was not ready for a read access. |
Remarks
The PI8042_SYNCH_READ_PORT callback can only be used in a PI8042_KEYBOARD_INITIALIZATION_ROUTINE callback. I8042prt specifies the read port callback in the ReadPort parameter that I8042prt inputs to a keyboard initialization routine.
The routine polls the hardware until a read is returned by the hardware or an internal time-out occurs.
Requirements
Requirement | Value |
---|---|
Target Platform | Desktop |
Header | ntdd8042.h (include Ntdd8042.h) |
IRQL | PASSIVE_LEVEL |