illumos: manual page: ddi_regs_map

DDI_REGS_MAP_SETUP(9F) Kernel Functions for Drivers DDI_REGS_MAP_SETUP(9F)

NAME

ddi_regs_map_setup - set up a mapping for a register address space

SYNOPSIS

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

int ddi_regs_map_setup(dev_info_t *dip, uint_t rnumber, caddr_t *addrp,
offset_t offset, offset_t len, ddi_device_acc_attr_t *accattrp,
ddi_acc_handle_t *handlep);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

dip
Pointer to the device's dev_info structure.

rnumber
Index of the desired tuple (0-based) in the register address
space set. See the Register Numbers section for more
information.

addrp
A platform-dependent value that, when added to an offset that
is less than or equal to the len parameter (see below), is
used for the dev_addr argument to the ddi_get, ddi_mem_get,
and ddi_io_get/put routines.

offset
Offset into the register address space.

len
Length to be mapped.

accattrp
Pointer to a device access attribute structure of this
mapping (see ddi_device_acc_attr(9S)).

handlep
Pointer to a data access handle.

DESCRIPTION

ddi_regs_map_setup() maps in the register set given by rnumber. The
register number determines which register set is mapped if more than one
exists.

offset specifies the starting location within the register space and len
indicates the size of the area to be mapped. If len is non-zero, it
overrides the length given in the register set description. If both len
and offset are 0, the entire space is mapped. The base of the mapped
register space is returned in addrp.

The device access attributes are specified in the location pointed by the
accattrp argument (see ddi_device_acc_attr(9S) for details).

The data access handle is returned in handlep. handlep is opaque;
drivers should not attempt to interpret its value. The handle is used by
the system to encode information for subsequent data access function
calls to maintain a consistent view between the host and the device.

Register Numbers

The reg property is an array of tuples. The size of each tuple varies
based on the hardware device type. For example, PCI and PCI Express
devices have one size, while ISA devices have a different size. Each
tuple describes a register space that indicates a way to communicate with
the device. The rnumber argument selects which of these to use.

For example, with PCI and PCI Express devices, the first base address
register (BAR) with a non-zero value is in rnumber 1 because it is the
second tuple in the reg property. The second BAR with a non-zero value
is in the third tuple (rnumber 2).

For a full treatment of the meaning of the reg property for PCI devices,
see pci(5). For PCI express devices, see pcie(5). For ISA devices, see
isa(5). For cardbus, see cardbus(5).

RETURN VALUES

ddi_regs_map_setup() returns:

DDI_SUCCESS
Successfully set up the mapping for data access.

DDI_FAILURE
Invalid register number rnumber, offset offset,
or length len.

DDI_ME_RNUMBER_RANGE
Invalid register number rnumber or unable to
find reg property.

DDI_REGS_ACC_CONFLICT
Cannot enable the register mapping due to access
conflicts with other enabled mappings.

Note that the return value DDI_ME_RNUMBER_RANGE is not supported on all
platforms. Also, there is potential overlap between DDI_ME_RNUMBER_RANGE
and DDI_FAILURE. Drivers should check for !=DDI_SUCCESS rather than
checking for a specific failure value.

CONTEXT

ddi_regs_map_setup() must be called from user or kernel context.

ATTRIBUTES