Manual Pages for UNIX Operating System command usage for man prop_op

Driver Entry Points                                   prop_op(9E)



NAME
     prop_op - report driver property information

SYNOPSIS
     #include 
     #include 
     #include 



     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  unaf-
                                           fected).


                 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



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Driver Entry Points                                   prop_op(9E)



                                      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  con-
                 tains  the  length  of  caller's buffer,  before
                 calling prop_op().


DESCRIPTION
     prop_op() is an entry point which reports the values of cer-
     tain  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 pro-
     perties 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:

     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.






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Driver Entry Points                                   prop_op(9E)



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 tem-
     perature 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 param-
     eter 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







SunOS 5.11           Last change: 8 Jul 1996                    3