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cardbus - configuration files for cardbus device drivers


The CardBus bus share the same configuration parameters with the PCI bus.
CardBus devices are self-identifying, which means that these devices
provide configuration parameters to the system that allow the system to
identify the device and its driver. The configuration parameters are
represented in the form of name-value pairs that can be retrieved using
the DDI property interfaces. See ddi_prop_lookup(9F) for details.

The CardBus bus properties of CardBus devices are derived from PCI
configuration space. Therefore, driver configuration files are not
necessary for these devices.

On some occasions, drivers for CardBus devices can use driver
configuration files to provide driver private properties through the
global property mechanism. See driver.conf(5) for further details. Driver
configuration files can also be used to augment or override properties
for a specific instance of a driver.

The CardBus nexus driver recognizes the following properties:

An arbitrary length array where each element of the array
consists of a 5-tuple of 32-bit values. Each array element
describes a logically contiguous mappable resource on the
PCI bus.

The first three values in the 5-tuple describe the PCI
address of the mappable resource. The first tuple contains
the following information:

Bits 0 - 7 8-bit register number
Bits 8 - 10 3-bit function number
Bits 11 - 15 5-bit device number
Bits 16 - 23 8-bit bus number
Bits 24 - 25 2-bit address space type identifier
Bits 31 - 28 Register number extended bits 8:11
for extended config space. Zero for
conventional configuration space.

The address space type identifier can be interpreted as

0x0 configuration space
0x1 I/O space
0x2 32-bit memory space address

The bus number is a unique identifying number assigned to
each bus within the PCI or PCIe domain.

The device number is a unique identifying number assigned
to each device on a PCI bus, PCIe logical bus, or CardBus
bus. A device number is unique only within the set of
device numbers for a particular bus or logical bus.

Each CardBus device can have one to eight logically
independent functions, each with its own independent set of
configuration registers. Each function on a device is
assigned a function number. For a device with only one
function, the function number must be 0.

The register number fields select a particular register
within the set of configuration registers corresponding to
the selected function. When the address space type
identifier indicates configuration space, non-zero register
number extended bits select registers in extended
configuration space.

The second and third values in the reg property 5-tuple
specify the 64-bit address of the mappable resource within
the PCI or PCIe address domain. Since the CardBus is a
32-bit bus, the second 32-bit tuple is not used. The third
32-bit tuple corresponds to the 32-bit address.

The fourth and fifth 32-bit values in the 5-tuple reg
property specify the size of the mappable resource. The
size is a 64-bit value. Since it's a 32-bit bus, only the
fifth tuple is used.

The driver can refer to the elements of this array by
index, and construct kernel mappings to these addresses
using ddi_regs_map_setup(9F). The index into the array is
passed as the rnumber argument of ddi_regs_map_setup(9F).

At a high-level interrupt context, you can use the ddi_get*
and ddi_put* family of functions to access I/O and memory
space. However, access to configuration space is not
allowed when running at a high-interrupt level.

This property consists of a single-integer element array.
Valid interrupt property values are 1, 2, 3, and 4. This
value is derived directly from the contents of the device's
configuration-interrupt-pin register.

A driver should use an index value of 0 when registering
its interrupt handler with the DDI interrupt interfaces.

All CardBus devices support the reg property. The device number and
function number as derived from the reg property are used to construct
the address part of the device name under /devices.

Only devices that generate interrupts support an interrupts property.

Occasionally it might be necessary to override or augment the
configuration information supplied by a CardBus device. This change can
be achieved by writing a driver configuration file that describes a
prototype device node specification containing the additional properties

For the system to merge the prototype node specification into an actual
device node, certain conditions must be met.

o First, the name property must be identical. The value of the
name property needs to match the binding name of the device.
The binding name is the name chosen by the system to bind a
driver to a device and is either an alias associated with the
driver or the hardware node name of the device.

o Second, the parent property must identify the PCI bus or PCIe
logical bus.

o Third, the unit-address property must identify the card. The
format of the unit-address property is:


where DD is the device number and F is the function number. If the
function number is 0, only DD is specified.


Example 1: Sample Configuration File

An example configuration file called ACME,scsi-hba.conf for a CardBus
device driver called ACME,scsi-hba follows:

# Copyright (c) 1995, ACME SCSI Host Bus Adaptor
# ident "@(#)ACME,scsi-hba.conf 1.1 96/02/04"
name="ACME,scsi-hba" parent="/pci@1,0/pci@1f,4000"
unit-address="3" scsi-initiator-id=6;

In this example, a property scsi-initiator-id specifies the SCSI bus
initiator id that the adapter should use, for just one particular
instance of adapter installed in the machine. The name property
identifies the driver and the parent property to identify the particular
bus the card is plugged into. This example uses the parent's full path
name to identify the bus. The unit-address property identifies the card
itself, with device number of 3 and function number of 0.

Two global driver properties are also created: hba-advanced-mode (which
has the string value on) and hba-dma-speed (which has the value 10 M
bit/s). These properties apply to all device nodes of the ACME,scsi-hba.


See attributes(7) for descriptions of the following attributes:

|Architecture | SPARC, x86 |


driver.conf(5), attributes(7), ddi_intr_add_handler(9F),
ddi_prop_lookup(9F), ddi_regs_map_setup(9F)

Writing Device Drivers

IEEE 1275 PCI Bus Binding

July 11, 2006 CARDBUS(5)