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

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

January 16, 2006 DDI_DEV_REGSIZE(9F)