NAME

ddi_prop_exists - check for the existence of a property

SYNOPSIS

#include <sys/ddi.h>
#include <sys/sunddi.h>
int ddi_prop_exists(dev_t match_dev, dev_info_t *dip, uint_t flags,


     char *name);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

match_dev

Device number associated with property or DDI_DEV_T_ANY.

dip

Pointer to the device info node of device whose property list should be searched.

flags

Possible flag values are some combination of:

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

ddi_prop_exists() checks for the existence of a property regardless of the property value data type.

Properties are searched for based on the dip, name, and match_dev. 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.

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

Usually, the match_dev argument should be set to the actual device number that this property is associated with. However, if the match_dev argument is DDI_DEV_T_ANY, then ddi_prop_exists() will match the request regardless of the match_dev the property was created with. That is the first property whose name matches name will be returned. If a property was created with match_dev set to DDI_DEV_T_NONE then the only way to look up this property is with a match_dev set to DDI_DEV_T_ANY. PROM properties are always created with match_dev set to DDI_DEV_T_NONE.

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

RETURN VALUES

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

CONTEXT

These functions can be called from user or kernel context.

EXAMPLES

Example 1 : Using ddi_prop_exists()

The following example demonstrates the use of ddi_prop_exists().

/*
	* Enable "whizzy" mode if the "whizzy-mode" property exists
	*/
	if (ddi_prop_exists(xx_dev, xx_dip, DDI_PROP_NOTPROM,
	        "whizzy-mode") == 1) {
	      xx_enable_whizzy_mode(xx_dip);
	} else {
	      xx_disable_whizzy_mode(xx_dip);
	}