LDI_PROP_EXISTS(9F) Kernel Functions for Drivers LDI_PROP_EXISTS(9F)

NAME

ldi_prop_exists - Check for the existence of a property

SYNOPSIS

#include <sys/sunldi.h>

int ldi_prop_exists(ldi_handle_t lh, uint_t flags, char *name);

INTERFACE LEVEL

illumos DDI specific (illumos DDI)

PARAMETERS

lh
Layered handle.


flags
Possible flag values are some combination of:


LDI_DEV_T_ANY
Match the lookup request independent of the actual
dev_t value that was used when the property was
created. The flag indicates any dev_t value
(including DDI_DEV_T_NONE) associated with a
possible property match satisfies the matching
criteria.


DDI_PROP_DONTPASS
Do not pass request to parent device information
node if the property is not found.


DDI_PROP_NOTPROM
Do not look at PROM properties (ignored on
platforms that do not support PROM properties).


name
String containing the name of the property.

DESCRIPTION

ldi_prop_exists() checks for the existence of a property associated with
a device represented by the layered driver handle, regardless of the
property value data type.


Properties are searched for based on the dip and dev_t values associated
with the layered handle, and the property name. This association is
handled by the layered driver infrastructure on behalf of the consumers
of ldi_prop_exists().


The property search order is as follows:

1. Search software-properties created by the driver.

2. Search the software properties created by the system (or nexus
nodes in the device info tree).

3. Search the driver global properties list.

4. If DDI_PROP_NOTPROM is not set, search the PROM properties (if
they exist).

5. If DDI_PROP_DONTPASS is not set, pass this request to the
parent device information node of the device represented by
the layered handle.

6. Return 0 if not found and 1 if found.


Typically, the specific dev_t value associated with the device
represented by the layered handle (ldi_handle_t) is used as a part of the
property match criteria. This association is handled by the layered
driver infrastructure on behalf of the consumers of the ldi property look
up functions.


However, if the LDI_DEV_T_ANY flag is used, the ldi property lookup
functions will match the request regardless of the dev_t value associated
with the property at the time of its creation. If a property was created
with a dev_t set to DDI_DEV_T_NONE, the only way to look up this property
is with the LDI_DEV_T_ANY flag. PROM properties are always created with
a dev_t set to DDI_DEV_T_NONE.


name must always be set to the name of the property being looked up.

RETURN VALUES

ldi_prop_exists() returns 1 if the property exists and 0 otherwise.

CONTEXT

This function may be called from user or kernel context.

EXAMPLE

The following example demonstrates the use of ldi_prop_exists().

/* Determine the existence of the "interrupts" property */
ldi_prop_exists(lh, LDI_DEV_T_ANY|DDI_PROP_NOTPROM, "interrupts");

SEE ALSO

ddi_prop_exists(9F)


Writing Device Drivers


June 3, 2003 LDI_PROP_EXISTS(9F)