Content-type: text/html Man page of prop_op

prop_op

Section: Driver Entry Points (9E)
Updated: 8 Jul 1996
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NAME

prop_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 caller's buffer. (valuep used as input).

PROP_LEN_AND_VAL_ALLOC

Get length and value into allocated 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 property 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().

 

DESCRIPTION

prop_op() is an entry point which reports the values of certain properties 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 properties for its device.   

RETURN VALUES

prop_op() should return:

"small and bold">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 memory. 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 temperature property. The driver tracks changes to temperature using a variable 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 ALSO

Intro(9E), ddi_prop_op(9F), ddi_prop_update(9F)

Writing Device Drivers


 

Index

NAME
SYNOPSIS
INTERFACE LEVEL
ARGUMENTS
DESCRIPTION
RETURN VALUES
EXAMPLES
SEE ALSO

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