man/man9f/ddi_device_zero.9f

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 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

Solaris DDI specific (Solaris 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