NAME

ddi_io_getb, ddi_io_getw, ddi_io_getl − read data from the mapped device register in I/O space

SYNOPSIS

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

uchar_t ddi_io_getb(ddi_acc_handle_t handle, int dev_port);

ushort_t ddi_io_getw(ddi_acc_handle_t handle, int dev_port);

ulong_t ddi_io_getl(ddi_acc_handle_t handle, int dev_port);

INTERFACE LEVEL

Solaris DDI specific (Solaris DDI). 

ARGUMENTS

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

dev_port The device port. 

DESCRIPTION

These routines generate a read of various sizes from the device port, dev_port, in I/O space. The ddi_io_getb(), ddi_io_getw(), and ddi_io_getl() functions read 8 bits, 16 bits, and 32 bits of data, respectively, from the device port, dev_port.

Each individual datum will automatically be translated to maintain a consistent view between the host and the device based on the encoded information in the data access handle.  The translation may involve byte-swapping if the host and the device have incompatible endian characteristics. 

CONTEXT

These functions can be called from user, kernel, or interrupt context. 

SEE ALSO

isa(4), ddi_io_putb(9F), ddi_io_rep_getb(9F), ddi_io_rep_putb(9F), ddi_regs_map_free(9F), ddi_regs_map_setup(9F), ddi_device_acc_attr(9S)

NOTES

For drivers using these functions, it may not be easy to maintain a single source to support devices with multiple bus versions.  For example, devices may offer I/O space in ISA bus (see isa(4)) but memory space only in PCI local bus.  This is especially true in instruction set architectures such as x86 where accesses to the memory and I/O space are different. 

SunOS 5.5.1  —  Last change: 31 Oct 1994