NAME¶
BUS_READ_IVAR
,
BUS_WRITE_IVAR
—
manipulate bus-specific device instance
variables
SYNOPSIS¶
#include
<sys/param.h>
#include
<sys/bus.h>
int
BUS_READ_IVAR
(
device_t
dev,
device_t
child,
int
index,
uintptr_t
*result);
int
BUS_WRITE_IVAR
(
device_t
dev,
device_t
child,
int
index,
uintptr_t
value);
DESCRIPTION¶
These two methods manage a bus specific set of instance variables of a child
device. The intention is that each different type of bus defines a set of
appropriate instance variables (such as ports and irqs for ISA bus etc.)
This information could be given to the child device as a struct but that makes
it hard for a bus to add or remove variables without forcing an edit and
recompile for all drivers which may not be possible for vendor supplied binary
drivers.
RETURN VALUES¶
Zero is returned on success, otherwise an appropriate error is returned.
SEE ALSO¶
device(9),
driver(9)
AUTHORS¶
This manual page was written by
Doug
Rabson.