handle custom I/O operations from another driver
int prefixdrvctl(void *idata,
channel_t channel, int cmd,
entry point routine
handles custom I/O operations
from another driver.
For hardware drivers,
a pointer to the device-specific instance data
as output by the CFG_ADD subfunction of the
entry point routine.
For software-only drivers, idata is undefined
and should not be referenced.
``Device instance'' in HDK Technical Reference.
Channel number used to select subcomponents
and/or operating modes of this device instance.
``Channel number'' in HDK Technical Reference.
Command argument the driver
routine inteprets as the operation to be performed.
Passes parameters between the calling driver
and this driver.
The interpretation of arg is dependent on
the command and the driver.
For example, the argument can be an integer
or it can be the address of a structure
that contains driver or hardware settings.
routine should return 0 for success,
or the appropriate error number
from those listed on the
This entry point is optional.
entry point is similar to
but is invoked from other kernel-level drivers
rather than from user processes.
Context and synchronization
The driver can block but cannot do operations such as
that require access to
the requesting process's address space.
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005