- read data from the mapped device register in I/O space
#include <sys/ddi.h> #include <sys/sunddi.h> uint8_t ddi_io_get8(ddi_acc_handle_t handle, uint8_t *dev_addr);
uint16_t ddi_io_get16(ddi_acc_handle_t handle, uint16_t *dev_addr);
uint32_t ddi_io_get32(ddi_acc_handle_t handle, uint32_t *dev_addr);
Data access handle returned from setup calls, such as ddi_regs_map_setup(9F).
These routines generate a read of various sizes from the device address, dev_addr, in I/O space. The ddi_io_get8(), ddi_io_get16(), and ddi_io_get32() functions read 8 bits, 16 bits, and 32 bits of data, respectively, from the device address, dev_addr.
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.
These functions can be called from user, kernel, or interrupt context.
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.
The functions described in this manual page previously used symbolic names which specified their data access size; the function names have been changed so they now specify a fixed-width data size. See the following table for the new name equivalents: