space and multiple sets of interface control registers, one per slave
interface.
-Bindings for the CCI node follow the ePAPR standard, available from:
-
-www.power.org/documentation/epapr-version-1-1/
-
-with the addition of the bindings described in this document which are
-specific to ARM.
-
* CCI interconnect node
Description: Describes a CCI cache coherent Interconnect component
as a tuple of cells, containing child address,
parent address and the size of the region in the
child address space.
- Definition: A standard property. Follow rules in the ePAPR for
- hierarchical bus addressing. CCI interfaces
- addresses refer to the parent node addressing
- scheme to declare their register bases.
+ Definition: A standard property. Follow rules in the Devicetree
+ Specification for hierarchical bus addressing. CCI
+ interfaces addresses refer to the parent node
+ addressing scheme to declare their register bases.
CCI interconnect node can define the following child nodes:
the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
defining properties for every cpu.
-Bindings for CPU nodes follow the ePAPR v1.1 standard, available from:
+Bindings for CPU nodes follow the Devicetree Specification, available from:
-https://www.power.org/documentation/epapr-version-1-1/
+https://www.devicetree.org/specifications/
with updates for 32-bit and 64-bit ARM systems provided in this document.
Convention used in this document
================================
-This document follows the conventions described in the ePAPR v1.1, with
-the addition:
+This document follows the conventions described in the Devicetree
+Specification, with the addition:
- square brackets define bitfields, eg reg[7:0] value of the bitfield in
the reg property contained in bits 7 down to 0
cpus and cpu node bindings definition
=====================================
-The ARM architecture, in accordance with the ePAPR, requires the cpus and cpu
-nodes to be present and contain the properties described below.
+The ARM architecture, in accordance with the Devicetree Specification,
+requires the cpus and cpu nodes to be present and contain the properties
+described below.
- cpus node
[4] ARM Architecture Reference Manuals
http://infocenter.arm.com/help/index.jsp
-[5] ePAPR standard
- https://www.power.org/documentation/epapr-version-1-1/
+[5] Devicetree Specification
+ https://www.devicetree.org/specifications/
PL310 and variants) based level 2 cache controller. All these various implementations
of the L2 cache controller have compatible programming models (Note 1).
Some of the properties that are just prefixed "cache-*" are taken from section
-3.7.3 of the ePAPR v1.1 specification which can be found at:
-https://www.power.org/wp-content/uploads/2012/06/Power_ePAPR_APPROVED_v1.1.pdf
+3.7.3 of the Devicetree Specification which can be found at:
+https://www.devicetree.org/specifications/
The ARM L2 cache representation in the device tree should be done as follows:
tree nodes.
The remainder of this document provides the topology bindings for ARM, based
-on the ePAPR standard, available from:
+on the Devicetree Specification, available from:
-http://www.power.org/documentation/epapr-version-1-1/
+https://www.devicetree.org/specifications/
If not stated otherwise, whenever a reference to a cpu node phandle is made its
value must point to a cpu node compliant with the cpu node bindings as
to function.
While "simple-pm-bus" follows the "simple-bus" set of properties, as specified
-in ePAPR, it is not an extension of "simple-bus".
+in the Devicetree Specification, it is not an extension of "simple-bus".
Required properties:
--------------------
Device trees may specify the device to be used for boot console output
-with a stdout-path property under /chosen, as described in ePAPR, e.g.
+with a stdout-path property under /chosen, as described in the Devicetree
+Specification, e.g.
/ {
chosen {
Common properties
-The ePAPR specification does not define any properties related to hardware
+The Devicetree Specification does not define any properties related to hardware
byteswapping, but endianness issues show up frequently in porting Linux to
different machine types. This document attempts to provide a consistent
way of handling byteswapping across drivers.
Definition: A list of clock name strings in the same order as the
clocks property.
- Note: All other standard properties (see the ePAPR) are allowed
- but are optional.
+ Note: All other standard properties (see the Devicetree Specification)
+ are allowed but are optional.
EXAMPLE
triplet that includes the child address, parent address, &
length.
- Note: All other standard properties (see the ePAPR) are allowed
- but are optional.
+ Note: All other standard properties (see the Devicetree Specification)
+ are allowed but are optional.
EXAMPLE
crypto@a0000 {
* References
-[1] Power.org (TM) Standard for Embedded Power Architecture (TM) Platform
- Requirements (ePAPR), Version 1.0, July 2008.
- (http://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.0.pdf)
+[1] Devicetree Specification
+ (https://www.devicetree.org/specifications/)
property;
- max-speed: number, specifies maximum speed in Mbit/s supported by the device;
- max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than
- the maximum frame size (there's contradiction in ePAPR).
+ the maximum frame size (there's contradiction in the Devicetree
+ Specification).
- phy-mode: string, operation mode of the PHY interface. This is now a de-facto
standard property; supported values are:
* "mii"
* "2000base-x",
* "2500base-x",
* "rxaui"
-- phy-connection-type: the same as "phy-mode" property but described in ePAPR;
+- phy-connection-type: the same as "phy-mode" property but described in the
+ Devicetree Specification;
- phy-handle: phandle, specifies a reference to a node representing a PHY
- device; this property is described in ePAPR and so preferred;
+ device; this property is described in the Devicetree Specification and so
+ preferred;
- phy: the same as "phy-handle" property, not recommended for new bindings.
- phy-device: the same as "phy-handle" property, not recommended for new
bindings.
Copyright 2013 Freescale Semiconductor Inc.
Power Architecture CPUs in Freescale SOCs are represented in device trees as
-per the definition in ePAPR.
+per the definition in the Devicetree Specification.
-In addition to the ePAPR definitions, the properties defined below may be
-present on CPU nodes.
+In addition to the the Devicetree Specification definitions, the properties
+defined below may be present on CPU nodes.
PROPERTIES
Freescale L2 Cache Controller
L2 cache is present in Freescale's QorIQ and QorIQ Qonverge platforms.
-The cache bindings explained below are ePAPR compliant
+The cache bindings explained below are Devicetree Specification compliant
Required Properties:
A single IRQ that handles port-write conditions is
specified by this property. (Typically shared with error).
- Note: All other standard properties (see the ePAPR) are allowed
- but are optional.
+ Note: All other standard properties (see the Devicetree Specification)
+ are allowed but are optional.
Example:
rmu: rmu@d3000 {
represents the LIODN associated with maintenance transactions
for the port.
-Note: All other standard properties (see ePAPR) are allowed but are optional.
+Note: All other standard properties (see the Devicetree Specification)
+are allowed but are optional.
Example:
from DMA operations originating from the bus. It provides a means of
defining a mapping or translation between the physical address space of
the bus and the physical address space of the parent of the bus.
- (for more information see ePAPR specification)
+ (for more information see the Devicetree Specification)
* DMA Bus child
Optional property:
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
-"simple-bus" is defined in the ePAPR 1.0 specification as a property
+"simple-bus" is defined in the Devicetree Specification as a property
meaning a simple memory mapped bus, so the of_platform_populate() code
could be written to just assume simple-bus compatible nodes will
always be traversed. However, we pass it in as an argument so that
00..1F -> 00 -> 00 -> 00
The default location of IO peripherals is above 0xf0000000. This may be changed
-using a "ranges" property in a device tree simple-bus node. See ePAPR 1.1, ยง6.5
-for details on the syntax and semantic of simple-bus nodes. The following
-limitations apply:
+using a "ranges" property in a device tree simple-bus node. See the Devicetree
+Specification, section 4.5 for details on the syntax and semantics of
+simple-bus nodes. The following limitations apply:
1. Only top level simple-bus nodes are considered
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