te
 Copyright (c) 1996, Sun Microsystems, Inc All Rights Reserved
 The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
 You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
 When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
 DDI_DEVICE_ZERO 9F "Sep 25, 1996"
 NAME
ddi_device_zero - zero fill the device

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



int ddi_device_zero(ddi_acc_handle_t handle, caddr_t dev_addr,
 size_t bytecount, ssize_t dev_advcnt, uint_t dev_datasz);




 INTERFACE LEVEL
illumos DDI specific (illumos DDI).

 PARAMETERS
handle 


The data access handle returned from setup calls, such as
ddi_regs_map_setup(9F).



dev_addr 


Beginning of the device address.



bytecount 


Number of bytes to zero.



dev_advcnt 


Number of dev_datasz units to advance on every access.



dev_datasz 


The size of each data word. Possible values are defined as:
DDI_DATA_SZ01_ACC 


1 byte data size



DDI_DATA_SZ02_ACC 


2 bytes data size



DDI_DATA_SZ04_ACC 


4 bytes data size



DDI_DATA_SZ08_ACC 


8 bytes data size







 DESCRIPTION
ddi_device_zero() function fills the given, bytecount, number of
byte of zeroes to the device register or memory.


The dev_advcnt argument determines the value of the device address,
dev_addr, on each access. A value of 0 will use the same device
address, dev_addr, on every access. A positive value increments the
device address in the next access while a negative value decrements the
address. The device address is incremented and decremented in dev_datasz
units.


The dev_datasz argument determines the size of data word on each access.

 RETURN VALUES
ddi_device_zero() returns:
DDI_SUCCESS 


Successfully zeroed the data.



DDI_FAILURE 


The byte count is not a multiple of dev_datasz.




 CONTEXT
ddi_device_zero() can be called from user, kernel, or interrupt context.

 SEE ALSO
 ddi_regs_map_free (9F),  ddi_regs_map_setup (9F) 

Writing Device Drivers