477 lines
12 KiB
Plaintext
477 lines
12 KiB
Plaintext
|
=================
|
||
|
|
ARM CPUs bindings
|
||
|
|
=================
|
||
|
|
|
||
|
|
The device tree allows to describe the layout of CPUs in a system through
|
||
|
|
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:
|
||
|
|
|
||
|
|
https://www.power.org/documentation/epapr-version-1-1/
|
||
|
|
|
||
|
|
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:
|
||
|
|
|
||
|
|
- 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.
|
||
|
|
|
||
|
|
- cpus node
|
||
|
|
|
||
|
|
Description: Container of cpu nodes
|
||
|
|
|
||
|
|
The node name must be "cpus".
|
||
|
|
|
||
|
|
A cpus node must define the following properties:
|
||
|
|
|
||
|
|
- #address-cells
|
||
|
|
Usage: required
|
||
|
|
Value type: <u32>
|
||
|
|
|
||
|
|
Definition depends on ARM architecture version and
|
||
|
|
configuration:
|
||
|
|
|
||
|
|
# On uniprocessor ARM architectures previous to v7
|
||
|
|
value must be 1, to enable a simple enumeration
|
||
|
|
scheme for processors that do not have a HW CPU
|
||
|
|
identification register.
|
||
|
|
# On 32-bit ARM 11 MPcore, ARM v7 or later systems
|
||
|
|
value must be 1, that corresponds to CPUID/MPIDR
|
||
|
|
registers sizes.
|
||
|
|
# On ARM v8 64-bit systems value should be set to 2,
|
||
|
|
that corresponds to the MPIDR_EL1 register size.
|
||
|
|
If MPIDR_EL1[63:32] value is equal to 0 on all CPUs
|
||
|
|
in the system, #address-cells can be set to 1, since
|
||
|
|
MPIDR_EL1[63:32] bits are not used for CPUs
|
||
|
|
identification.
|
||
|
|
- #size-cells
|
||
|
|
Usage: required
|
||
|
|
Value type: <u32>
|
||
|
|
Definition: must be set to 0
|
||
|
|
|
||
|
|
- cpu node
|
||
|
|
|
||
|
|
Description: Describes a CPU in an ARM based system
|
||
|
|
|
||
|
|
PROPERTIES
|
||
|
|
|
||
|
|
- device_type
|
||
|
|
Usage: required
|
||
|
|
Value type: <string>
|
||
|
|
Definition: must be "cpu"
|
||
|
|
- reg
|
||
|
|
Usage and definition depend on ARM architecture version and
|
||
|
|
configuration:
|
||
|
|
|
||
|
|
# On uniprocessor ARM architectures previous to v7
|
||
|
|
this property is required and must be set to 0.
|
||
|
|
|
||
|
|
# On ARM 11 MPcore based systems this property is
|
||
|
|
required and matches the CPUID[11:0] register bits.
|
||
|
|
|
||
|
|
Bits [11:0] in the reg cell must be set to
|
||
|
|
bits [11:0] in CPU ID register.
|
||
|
|
|
||
|
|
All other bits in the reg cell must be set to 0.
|
||
|
|
|
||
|
|
# On 32-bit ARM v7 or later systems this property is
|
||
|
|
required and matches the CPU MPIDR[23:0] register
|
||
|
|
bits.
|
||
|
|
|
||
|
|
Bits [23:0] in the reg cell must be set to
|
||
|
|
bits [23:0] in MPIDR.
|
||
|
|
|
||
|
|
All other bits in the reg cell must be set to 0.
|
||
|
|
|
||
|
|
# On ARM v8 64-bit systems this property is required
|
||
|
|
and matches the MPIDR_EL1 register affinity bits.
|
||
|
|
|
||
|
|
* If cpus node's #address-cells property is set to 2
|
||
|
|
|
||
|
|
The first reg cell bits [7:0] must be set to
|
||
|
|
bits [39:32] of MPIDR_EL1.
|
||
|
|
|
||
|
|
The second reg cell bits [23:0] must be set to
|
||
|
|
bits [23:0] of MPIDR_EL1.
|
||
|
|
|
||
|
|
* If cpus node's #address-cells property is set to 1
|
||
|
|
|
||
|
|
The reg cell bits [23:0] must be set to bits [23:0]
|
||
|
|
of MPIDR_EL1.
|
||
|
|
|
||
|
|
All other bits in the reg cells must be set to 0.
|
||
|
|
|
||
|
|
- compatible:
|
||
|
|
Usage: required
|
||
|
|
Value type: <string>
|
||
|
|
Definition: should be one of:
|
||
|
|
"arm,arm710t"
|
||
|
|
"arm,arm720t"
|
||
|
|
"arm,arm740t"
|
||
|
|
"arm,arm7ej-s"
|
||
|
|
"arm,arm7tdmi"
|
||
|
|
"arm,arm7tdmi-s"
|
||
|
|
"arm,arm9es"
|
||
|
|
"arm,arm9ej-s"
|
||
|
|
"arm,arm920t"
|
||
|
|
"arm,arm922t"
|
||
|
|
"arm,arm925"
|
||
|
|
"arm,arm926e-s"
|
||
|
|
"arm,arm926ej-s"
|
||
|
|
"arm,arm940t"
|
||
|
|
"arm,arm946e-s"
|
||
|
|
"arm,arm966e-s"
|
||
|
|
"arm,arm968e-s"
|
||
|
|
"arm,arm9tdmi"
|
||
|
|
"arm,arm1020e"
|
||
|
|
"arm,arm1020t"
|
||
|
|
"arm,arm1022e"
|
||
|
|
"arm,arm1026ej-s"
|
||
|
|
"arm,arm1136j-s"
|
||
|
|
"arm,arm1136jf-s"
|
||
|
|
"arm,arm1156t2-s"
|
||
|
|
"arm,arm1156t2f-s"
|
||
|
|
"arm,arm1176jzf"
|
||
|
|
"arm,arm1176jz-s"
|
||
|
|
"arm,arm1176jzf-s"
|
||
|
|
"arm,arm11mpcore"
|
||
|
|
"arm,cortex-a5"
|
||
|
|
"arm,cortex-a7"
|
||
|
|
"arm,cortex-a8"
|
||
|
|
"arm,cortex-a9"
|
||
|
|
"arm,cortex-a12"
|
||
|
|
"arm,cortex-a15"
|
||
|
|
"arm,cortex-a17"
|
||
|
|
"arm,cortex-a53"
|
||
|
|
"arm,cortex-a57"
|
||
|
|
"arm,cortex-a72"
|
||
|
|
"arm,cortex-m0"
|
||
|
|
"arm,cortex-m0+"
|
||
|
|
"arm,cortex-m1"
|
||
|
|
"arm,cortex-m3"
|
||
|
|
"arm,cortex-m4"
|
||
|
|
"arm,cortex-r4"
|
||
|
|
"arm,cortex-r5"
|
||
|
|
"arm,cortex-r7"
|
||
|
|
"brcm,brahma-b15"
|
||
|
|
"brcm,vulcan"
|
||
|
|
"cavium,thunder"
|
||
|
|
"faraday,fa526"
|
||
|
|
"intel,sa110"
|
||
|
|
"intel,sa1100"
|
||
|
|
"marvell,feroceon"
|
||
|
|
"marvell,mohawk"
|
||
|
|
"marvell,pj4a"
|
||
|
|
"marvell,pj4b"
|
||
|
|
"marvell,sheeva-v5"
|
||
|
|
"nvidia,tegra132-denver"
|
||
|
|
"qcom,krait"
|
||
|
|
"qcom,kryo"
|
||
|
|
"qcom,scorpion"
|
||
|
|
- enable-method
|
||
|
|
Value type: <stringlist>
|
||
|
|
Usage and definition depend on ARM architecture version.
|
||
|
|
# On ARM v8 64-bit this property is required and must
|
||
|
|
be one of:
|
||
|
|
"psci"
|
||
|
|
"spin-table"
|
||
|
|
# On ARM 32-bit systems this property is optional and
|
||
|
|
can be one of:
|
||
|
|
"allwinner,sun6i-a31"
|
||
|
|
"allwinner,sun8i-a23"
|
||
|
|
"arm,realview-smp"
|
||
|
|
"brcm,bcm11351-cpu-method"
|
||
|
|
"brcm,bcm23550"
|
||
|
|
"brcm,bcm-nsp-smp"
|
||
|
|
"brcm,brahma-b15"
|
||
|
|
"marvell,armada-375-smp"
|
||
|
|
"marvell,armada-380-smp"
|
||
|
|
"marvell,armada-390-smp"
|
||
|
|
"marvell,armada-xp-smp"
|
||
|
|
"mediatek,mt6589-smp"
|
||
|
|
"mediatek,mt81xx-tz-smp"
|
||
|
|
"qcom,gcc-msm8660"
|
||
|
|
"qcom,kpss-acc-v1"
|
||
|
|
"qcom,kpss-acc-v2"
|
||
|
|
"renesas,apmu"
|
||
|
|
"rockchip,rk3036-smp"
|
||
|
|
"rockchip,rk3066-smp"
|
||
|
|
"ste,dbx500-smp"
|
||
|
|
|
||
|
|
- cpu-release-addr
|
||
|
|
Usage: required for systems that have an "enable-method"
|
||
|
|
property value of "spin-table".
|
||
|
|
Value type: <prop-encoded-array>
|
||
|
|
Definition:
|
||
|
|
# On ARM v8 64-bit systems must be a two cell
|
||
|
|
property identifying a 64-bit zero-initialised
|
||
|
|
memory location.
|
||
|
|
|
||
|
|
- qcom,saw
|
||
|
|
Usage: required for systems that have an "enable-method"
|
||
|
|
property value of "qcom,kpss-acc-v1" or
|
||
|
|
"qcom,kpss-acc-v2"
|
||
|
|
Value type: <phandle>
|
||
|
|
Definition: Specifies the SAW[1] node associated with this CPU.
|
||
|
|
|
||
|
|
- qcom,acc
|
||
|
|
Usage: required for systems that have an "enable-method"
|
||
|
|
property value of "qcom,kpss-acc-v1" or
|
||
|
|
"qcom,kpss-acc-v2"
|
||
|
|
Value type: <phandle>
|
||
|
|
Definition: Specifies the ACC[2] node associated with this CPU.
|
||
|
|
|
||
|
|
- cpu-idle-states
|
||
|
|
Usage: Optional
|
||
|
|
Value type: <prop-encoded-array>
|
||
|
|
Definition:
|
||
|
|
# List of phandles to idle state nodes supported
|
||
|
|
by this cpu [3].
|
||
|
|
|
||
|
|
- capacity-dmips-mhz
|
||
|
|
Usage: Optional
|
||
|
|
Value type: <u32>
|
||
|
|
Definition:
|
||
|
|
# u32 value representing CPU capacity [3] in
|
||
|
|
DMIPS/MHz, relative to highest capacity-dmips-mhz
|
||
|
|
in the system.
|
||
|
|
|
||
|
|
- rockchip,pmu
|
||
|
|
Usage: optional for systems that have an "enable-method"
|
||
|
|
property value of "rockchip,rk3066-smp"
|
||
|
|
While optional, it is the preferred way to get access to
|
||
|
|
the cpu-core power-domains.
|
||
|
|
Value type: <phandle>
|
||
|
|
Definition: Specifies the syscon node controlling the cpu core
|
||
|
|
power domains.
|
||
|
|
|
||
|
|
- dynamic-power-coefficient
|
||
|
|
Usage: optional
|
||
|
|
Value type: <prop-encoded-array>
|
||
|
|
Definition: A u32 value that represents the running time dynamic
|
||
|
|
power coefficient in units of mW/MHz/uV^2. The
|
||
|
|
coefficient can either be calculated from power
|
||
|
|
measurements or derived by analysis.
|
||
|
|
|
||
|
|
The dynamic power consumption of the CPU is
|
||
|
|
proportional to the square of the Voltage (V) and
|
||
|
|
the clock frequency (f). The coefficient is used to
|
||
|
|
calculate the dynamic power as below -
|
||
|
|
|
||
|
|
Pdyn = dynamic-power-coefficient * V^2 * f
|
||
|
|
|
||
|
|
where voltage is in uV, frequency is in MHz.
|
||
|
|
|
||
|
|
Example 1 (dual-cluster big.LITTLE system 32-bit):
|
||
|
|
|
||
|
|
cpus {
|
||
|
|
#size-cells = <0>;
|
||
|
|
#address-cells = <1>;
|
||
|
|
|
||
|
|
cpu@0 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a15";
|
||
|
|
reg = <0x0>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@1 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a15";
|
||
|
|
reg = <0x1>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a7";
|
||
|
|
reg = <0x100>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@101 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a7";
|
||
|
|
reg = <0x101>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
Example 2 (Cortex-A8 uniprocessor 32-bit system):
|
||
|
|
|
||
|
|
cpus {
|
||
|
|
#size-cells = <0>;
|
||
|
|
#address-cells = <1>;
|
||
|
|
|
||
|
|
cpu@0 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a8";
|
||
|
|
reg = <0x0>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
Example 3 (ARM 926EJ-S uniprocessor 32-bit system):
|
||
|
|
|
||
|
|
cpus {
|
||
|
|
#size-cells = <0>;
|
||
|
|
#address-cells = <1>;
|
||
|
|
|
||
|
|
cpu@0 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,arm926ej-s";
|
||
|
|
reg = <0x0>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
Example 4 (ARM Cortex-A57 64-bit system):
|
||
|
|
|
||
|
|
cpus {
|
||
|
|
#size-cells = <0>;
|
||
|
|
#address-cells = <2>;
|
||
|
|
|
||
|
|
cpu@0 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x0>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@1 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x1>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x100>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@101 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x101>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@10000 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x10000>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@10001 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x10001>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@10100 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x10100>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@10101 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x0 0x10101>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100000000 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x0>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100000001 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x1>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100000100 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x100>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100000101 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x101>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100010000 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x10000>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100010001 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x10001>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100010100 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x10100>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
|
||
|
|
cpu@100010101 {
|
||
|
|
device_type = "cpu";
|
||
|
|
compatible = "arm,cortex-a57";
|
||
|
|
reg = <0x1 0x10101>;
|
||
|
|
enable-method = "spin-table";
|
||
|
|
cpu-release-addr = <0 0x20000000>;
|
||
|
|
};
|
||
|
|
};
|
||
|
|
|
||
|
|
--
|
||
|
|
[1] arm/msm/qcom,saw2.txt
|
||
|
|
[2] arm/msm/qcom,kpss-acc.txt
|
||
|
|
[3] ARM Linux kernel documentation - idle states bindings
|
||
|
|
Documentation/devicetree/bindings/arm/idle-states.txt
|
||
|
|
[3] ARM Linux kernel documentation - cpu capacity bindings
|
||
|
|
Documentation/devicetree/bindings/arm/cpu-capacity.txt
|