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

ldi_prop_get_int, ldi_prop_get_int64 - Lookup integer property

#include <sys/sunldi.h>
int ldi_prop_get_int(ldi_handle_t lh, uint_t flags, char *name,

int defvalue);

int64_t ldi_prop_get_int64(ldi_handle_t lh, uint_t flags, char *name,

int64_t defvalue);

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. 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 property not found.

DDI_PROP_NOTPROM

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

name

String containing the property name.

defvalue

Integer value that is returned if the property is not found.

illumos DDI specific (illumos DDI)

The ldi_prop_get_int() and ldi_prop_get_int64() functions search for an integer property associated with a device represented by the layered driver handle. If the integer property is found, the functions return the property value.

Properties are searched for based on the dip and dev_t values associated with the layered handle, the property name, and type of the data (integer).

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 defvalue.

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 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.

The return value of the routine is the value of property. If the property is not found, the argument defvalue is returned as the property value.

ldi_prop_get_int64() does not search the PROM for 64-bit property values.

ldi_prop_get_int() and ldi_prop_get_int64() return the property value. If the property is not found, the argument defvalue is returned. If the property is found, but cannot be decoded into an int or an int64_t, DDI_PROP_NOT_FOUND is returned.

ldi_prop_get_int() and ldi_prop_get_int64() can be called from user or kernel context.

Using ldi_prop_get_int64().


The following example demonstrates the use of ldi_prop_get_int64().

/*
* Get the value of the integer "timeout" property, using
* our own default if no such property exists
*/
int64_t timeout, defval;
timeout = ldi_prop_get_int64(lh, LDI_DEV_T_ANY|DDI_PROP_DONTPASS,
propname, defval);

ddi_prop_get_int(9F), ddi_prop_get_int64(9F), ldi_prop_exists(9F)

Writing Device Drivers

June 3, 2003 OmniOS