opensolaris man page for ddi_dev_regsize

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

NAME
       ddi_dev_regsize - return the size of a device's register

SYNOPSIS
       #include <sys/conf.h>
       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       int ddi_dev_regsize(dev_info_t *dip, uint_t rnumber, off_t *resultp);

INTERFACE LEVEL
       Solaris DDI specific (Solaris DDI).

PARAMETERS
       dip	  A pointer to the device's dev_info structure.

       rnumber	  The  ordinal register number. Device registers are associated with a dev_info and are enumerated in arbitrary sets from 0 on up.
		  The number of registers a device has can be determined from a call to ddi_dev_nregs(9F).

       resultp	  Pointer to an integer that holds the size, in bytes, of the described register (if it exists).

DESCRIPTION
       The ddi_dev_regsize() function returns the size, in bytes, of the device register specified by dip and rnumber. This is	useful	when,  for
       example, one of the registers is a frame buffer with a varying size known only to its proms.

RETURN VALUES
       The ddi_dev_regsize() function returns:

       DDI_SUCCESS    A successful return. The size, in bytes, of the specified register, is set in resultp.

       DDI_FAILURE    An invalid (nonexistent) register number was specified.

CONTEXT
       The ddi_dev_regsize() function can be called from user, interrupt, or kernel context.

SEE ALSO
       ddi_dev_nintrs(9F), ddi_dev_nregs(9F)

       Writing Device Drivers

SunOS 5.11							    16 Jan 2006 					       ddi_dev_regsize(9F)