prop_op(9E) Driver Entry Points prop_op(9E)NAMEprop_op - report driver property information
SYNOPSIS
#include <sys/types.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
int prefixprop_op(dev_t dev, dev_info_t *dip,
ddi_prop_op_t prop_op, int flags, char *name, caddr_t valuep,
int *lengthp);
INTERFACE LEVEL
Solaris DDI specific (Solaris DDI). This entry point is required, but
it can be ddi_prop_op(9F).
ARGUMENTS
dev Device number associated with this device.
dip A pointer to the device information structure for this
device.
prop_op Property operator. Valid operators are:
PROP_LEN Get property length only. (valuep
unaffected).
PROP_LEN_AND_VAL_BUF Get length and value into call‐
er's buffer. (valuep used as
input).
PROP_LEN_AND_VAL_ALLOC Get length and value into allo‐
cated buffer. (valuep returned as
pointer to pointer to allocated
buffer).
flags The only possible flag value is:
DDI_PROP_DONTPASS Do not pass request to parent if prop‐
erty not found.
name Pointer to name of property to be interrogated.
valuep If prop_op is PROP_LEN_AND_VAL_BUF, this should be a
pointer to the user's buffer. If prop_op is
PROP_LEN_AND_VAL_ALLOC, this should be the address of a
pointer.
lengthp On exit, *lengthp will contain the property length. If
prop_op is PROP_LEN_AND_VAL_BUF then lengthp should point
to an int that contains the length of caller's buffer,
before calling prop_op().
DESCRIPTIONprop_op() is an entry point which reports the values of certain proper‐
ties of the driver or device to the system. Each driver must have a
prefix prop_op entry point, but most drivers that do not need to create
or manage their own properties can use ddi_prop_op() for this entry
point. Then the driver can use ddi_prop_update(9F) to create proper‐
ties for its device.
RETURN VALUESprop_op() should return:
DDI_PROP_SUCCESS Property found and returned.
DDI_PROP_NOT_FOUND Property not found.
DDI_PROP_UNDEFINED Prop explicitly undefined.
DDI_PROP_NO_MEMORY Property found, but unable to allocate mem‐
ory. lengthp has the correct property
length.
DDI_PROP_BUF_TOO_SMALL Property found, but the supplied buffer is
too small. lengthp has the correct property
length.
EXAMPLES
Example 1 Using prop_op() to Report Property Information
In the following example, prop_op() intercepts requests for the temper‐
ature property. The driver tracks changes to temperature using a vari‐
able in the state structure in order to avoid frequent calls to
ddi_prop_update(9F). The temperature property is only updated when a
request is made for this property. It then uses the system routine
ddi_prop_op(9F) to process the property request. If the property
request is not specific to a device, the driver does not intercept the
request. This is indicated when the value of the dev parameter is
equal to DDI_DEV_T_ANY.
int temperature; /* current device temperature */
.
.
.
static int
xxprop_op(dev_t dev, dev_info_t *dip, ddi_prop_op_t prop_op,
int flags, char *name, caddr_t valuep, int *lengthp)
{
int instance;
struct xxstate *xsp;
if (dev == DDI_DEV_T_ANY)
goto skip;
instance = getminor(dev);
xsp = ddi_get_soft_state(statep, instance);
if (xsp == NULL)
return (DDI_PROP_NOT_FOUND);
if (strcmp(name, "temperature") == 0) {
ddi_prop_update_int(dev, dip,\
"temperature", temperature);
}
/* other cases... */
skip:
return (ddi_prop_op(dev, dip, prop_op, flags,\
name, valuep, lengthp));
}
SEE ALSOIntro(9E), ddi_prop_op(9F), ddi_prop_update(9F)
Writing Device Drivers
SunOS 5.11 8 Jul 1996 prop_op(9E)
