xref: /illumos-gate/usr/src/man/man9f/ddi_dev_regsize.9f (revision 74e12c43fe52f2c30f36e65a4d0fb0e8dfd7068a)
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DDI_DEV_REGSIZE 9F "Jan 16, 2006"
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
illumos DDI specific (illumos 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