linux_dsm_epyc7002/Documentation/devicetree/bindings/arm/cpus.txt
Linus Torvalds 167569343f ARM: SoC platform updates for 4.17
This release brings up a new platform based on the old ARM9 core: the
 Nuvoton NPCM is used as a baseboard management controller, competing
 with the better known ASpeed AST2xx series.
 
 Another important change is the addition of ARMv7-A based chips
 in mach-stm32. The older parts in this platform are ARMv7-M based
 microcontrollers, now they are expanding to general-purpose workloads.
 
 The other changes are the usual defconfig updates to enable additional
 drivers, lesser bugfixes. The largest updates as often are the ongoing
 OMAP cleanups, but we also have a number of changes for the older
 PXA and davinci platforms this time.
 
 For the Renesas shmobile/r-car platform, some new infrastructure
 is needed to make the watchdog work correctly.
 
 Supporting Multiprocessing on Allwinner A80 required a significant
 amount of new code, but is not doing anything unexpected.
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Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform updates from Arnd Bergmann:
 "This release brings up a new platform based on the old ARM9 core: the
  Nuvoton NPCM is used as a baseboard management controller, competing
  with the better known ASpeed AST2xx series.

  Another important change is the addition of ARMv7-A based chips in
  mach-stm32. The older parts in this platform are ARMv7-M based
  microcontrollers, now they are expanding to general-purpose workloads.

  The other changes are the usual defconfig updates to enable additional
  drivers, lesser bugfixes. The largest updates as often are the ongoing
  OMAP cleanups, but we also have a number of changes for the older PXA
  and davinci platforms this time.

  For the Renesas shmobile/r-car platform, some new infrastructure is
  needed to make the watchdog work correctly.

  Supporting Multiprocessing on Allwinner A80 required a significant
  amount of new code, but is not doing anything unexpected"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (179 commits)
  arm: npcm: modify configuration for the NPCM7xx BMC.
  MAINTAINERS: update entry for ARM/berlin
  ARM: omap2: fix am43xx build without L2X0
  ARM: davinci: da8xx: simplify CFGCHIP regmap_config
  ARM: davinci: da8xx: fix oops in USB PHY driver due to stack allocated platform_data
  ARM: multi_v7_defconfig: add NXP FlexCAN IP support
  ARM: multi_v7_defconfig: enable thermal driver for i.MX devices
  ARM: multi_v7_defconfig: add RN5T618 PMIC family support
  ARM: multi_v7_defconfig: add NXP graphics drivers
  ARM: multi_v7_defconfig: add GPMI NAND controller support
  ARM: multi_v7_defconfig: add OCOTP driver for NXP SoCs
  ARM: multi_v7_defconfig: configure I2C driver built-in
  arm64: defconfig: add CONFIG_UNIPHIER_THERMAL and CONFIG_SNI_AVE
  ARM: imx: fix imx6sll-only build
  ARM: imx: select ARM_CPU_SUSPEND for CPU_IDLE as well
  ARM: mxs_defconfig: Re-sync defconfig
  ARM: imx_v4_v5_defconfig: Use the generic fsl-asoc-card driver
  ARM: imx_v4_v5_defconfig: Re-sync defconfig
  arm64: defconfig: enable stmmac ethernet to defconfig
  ARM: EXYNOS: Simplify code in coupled CPU idle hot path
  ...
2018-04-05 21:21:08 -07:00

489 lines
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=================
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 Devicetree Specification, available from:
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 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 Devicetree Specification,
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-a73"
"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,brahma-b53"
"brcm,vulcan"
"cavium,thunder"
"cavium,thunder2"
"faraday,fa526"
"intel,sa110"
"intel,sa1100"
"marvell,feroceon"
"marvell,mohawk"
"marvell,pj4a"
"marvell,pj4b"
"marvell,sheeva-v5"
"nvidia,tegra132-denver"
"nvidia,tegra186-denver"
"qcom,krait"
"qcom,kryo"
"qcom,kryo385"
"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:
"actions,s500-smp"
"allwinner,sun6i-a31"
"allwinner,sun8i-a23"
"allwinner,sun9i-a80-smp"
"amlogic,meson8-smp"
"amlogic,meson8b-smp"
"arm,realview-smp"
"brcm,bcm11351-cpu-method"
"brcm,bcm23550"
"brcm,bcm2836-smp"
"brcm,bcm-nsp-smp"
"brcm,brahma-b15"
"marvell,armada-375-smp"
"marvell,armada-380-smp"
"marvell,armada-390-smp"
"marvell,armada-xp-smp"
"marvell,98dx3236-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 [4] 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
[4] ARM Linux kernel documentation - cpu capacity bindings
Documentation/devicetree/bindings/arm/cpu-capacity.txt