1 # SPDX-License-Identifier: GPL-2.0
4 $id: http://devicetree.org/schemas/arm/cpus.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
10 - Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
13 The device tree allows to describe the layout of CPUs in a system through
14 the "cpus" node, which in turn contains a number of subnodes (ie "cpu")
15 defining properties for every cpu.
17 Bindings for CPU nodes follow the Devicetree Specification, available from:
19 https://www.devicetree.org/specifications/
21 with updates for 32-bit and 64-bit ARM systems provided in this document.
23 ================================
24 Convention used in this document
25 ================================
27 This document follows the conventions described in the Devicetree
28 Specification, with the addition:
30 - square brackets define bitfields, eg reg[7:0] value of the bitfield in
31 the reg property contained in bits 7 down to 0
33 =====================================
34 cpus and cpu node bindings definition
35 =====================================
37 The ARM architecture, in accordance with the Devicetree Specification,
38 requires the cpus and cpu nodes to be present and contain the properties
45 Usage and definition depend on ARM architecture version and
48 On uniprocessor ARM architectures previous to v7
49 this property is required and must be set to 0.
51 On ARM 11 MPcore based systems this property is
52 required and matches the CPUID[11:0] register bits.
54 Bits [11:0] in the reg cell must be set to
55 bits [11:0] in CPU ID register.
57 All other bits in the reg cell must be set to 0.
59 On 32-bit ARM v7 or later systems this property is
60 required and matches the CPU MPIDR[23:0] register
63 Bits [23:0] in the reg cell must be set to
66 All other bits in the reg cell must be set to 0.
68 On ARM v8 64-bit systems this property is required
69 and matches the MPIDR_EL1 register affinity bits.
71 * If cpus node's #address-cells property is set to 2
73 The first reg cell bits [7:0] must be set to
74 bits [39:32] of MPIDR_EL1.
76 The second reg cell bits [23:0] must be set to
77 bits [23:0] of MPIDR_EL1.
79 * If cpus node's #address-cells property is set to 1
81 The reg cell bits [23:0] must be set to bits [23:0]
84 All other bits in the reg cells must be set to 0.
120 - arm,armv8 # Only for s/w models
172 - nvidia,tegra132-denver
173 - nvidia,tegra186-denver
174 - nvidia,tegra194-carmel
193 $ref: '/schemas/types.yaml#/definitions/string'
195 # On ARM v8 64-bit this property is required
199 # On ARM 32-bit systems this property is optional
202 - allwinner,sun6i-a31
203 - allwinner,sun8i-a23
204 - allwinner,sun9i-a80-smp
205 - allwinner,sun8i-a83t-smp
207 - amlogic,meson8b-smp
210 - brcm,bcm11351-cpu-method
216 - marvell,armada-375-smp
217 - marvell,armada-380-smp
218 - marvell,armada-390-smp
219 - marvell,armada-xp-smp
220 - marvell,98dx3236-smp
222 - mediatek,mt6589-smp
223 - mediatek,mt81xx-tz-smp
229 # Only valid on ARM 32-bit, see above for ARM v8 64-bit
232 - renesas,r9a06g032-smp
233 - rockchip,rk3036-smp
234 - rockchip,rk3066-smp
235 - socionext,milbeaut-m10v-smp
242 - $ref: '/schemas/types.yaml#/definitions/uint32'
243 - $ref: '/schemas/types.yaml#/definitions/uint64'
245 The DT specification defines this as 64-bit always, but some 32-bit Arm
246 systems have used a 32-bit value which must be supported.
247 Required for systems that have an "enable-method"
248 property value of "spin-table".
251 $ref: '/schemas/types.yaml#/definitions/phandle-array'
255 List of phandles to idle state nodes supported
256 by this cpu (see ./idle-states.yaml).
260 u32 value representing CPU capacity (see ./cpu-capacity.txt) in
261 DMIPS/MHz, relative to highest capacity-dmips-mhz
264 cci-control-port: true
266 dynamic-power-coefficient:
267 $ref: '/schemas/types.yaml#/definitions/uint32'
269 A u32 value that represents the running time dynamic
270 power coefficient in units of uW/MHz/V^2. The
271 coefficient can either be calculated from power
272 measurements or derived by analysis.
274 The dynamic power consumption of the CPU is
275 proportional to the square of the Voltage (V) and
276 the clock frequency (f). The coefficient is used to
277 calculate the dynamic power as below -
279 Pdyn = dynamic-power-coefficient * V^2 * f
281 where voltage is in V, frequency is in MHz.
286 List of phandles and performance domain specifiers, as defined by
287 bindings of the performance domain provider. See also
288 dvfs/performance-domain.yaml.
292 List of phandles and PM domain specifiers, as defined by bindings of the
293 PM domain provider (see also ../power_domain.txt).
297 A list of power domain name strings sorted in the same order as the
298 power-domains property.
300 For PSCI based platforms, the name corresponding to the index of the PSCI
301 PM domain provider, must be "psci".
304 $ref: '/schemas/types.yaml#/definitions/phandle'
306 Specifies the SAW* node associated with this CPU.
308 Required for systems that have an "enable-method" property
309 value of "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2"
311 * arm/msm/qcom,saw2.txt
314 $ref: '/schemas/types.yaml#/definitions/phandle'
316 Specifies the ACC* node associated with this CPU.
318 Required for systems that have an "enable-method" property
319 value of "qcom,kpss-acc-v1", "qcom,kpss-acc-v2", "qcom,msm8226-smp" or
322 * arm/msm/qcom,kpss-acc.txt
325 $ref: '/schemas/types.yaml#/definitions/phandle'
327 Specifies the syscon node controlling the cpu core power domains.
329 Optional for systems that have an "enable-method"
330 property value of "rockchip,rk3066-smp"
331 While optional, it is the preferred way to get access to
332 the cpu-core power-domains.
335 $ref: '/schemas/types.yaml#/definitions/uint32'
337 Required for systems that have an "enable-method" property value of
338 "brcm,bcm11351-cpu-method", "brcm,bcm23550" or "brcm,bcm-nsp-smp".
340 This includes the following SoCs: |
341 BCM11130, BCM11140, BCM11351, BCM28145, BCM28155, BCM21664, BCM23550
342 BCM58522, BCM58525, BCM58535, BCM58622, BCM58623, BCM58625, BCM88312
344 The secondary-boot-reg property is a u32 value that specifies the
345 physical address of the register used to request the ROM holding pen
346 code release a secondary CPU. The value written to the register is
347 formed by encoding the target CPU id into the low bits of the
348 physical start address it should jump to.
351 # If the enable-method property contains one of those values
356 - brcm,bcm11351-cpu-method
359 # and if enable-method is present
373 rockchip,pmu: [enable-method]
375 additionalProperties: true
381 #address-cells = <1>;
385 compatible = "arm,cortex-a15";
391 compatible = "arm,cortex-a15";
397 compatible = "arm,cortex-a7";
403 compatible = "arm,cortex-a7";
409 // Example 2 (Cortex-A8 uniprocessor 32-bit system):
412 #address-cells = <1>;
416 compatible = "arm,cortex-a8";
422 // Example 3 (ARM 926EJ-S uniprocessor 32-bit system):
425 #address-cells = <1>;
429 compatible = "arm,arm926ej-s";
435 // Example 4 (ARM Cortex-A57 64-bit system):
438 #address-cells = <2>;
442 compatible = "arm,cortex-a57";
444 enable-method = "spin-table";
445 cpu-release-addr = <0 0x20000000>;
450 compatible = "arm,cortex-a57";
452 enable-method = "spin-table";
453 cpu-release-addr = <0 0x20000000>;
458 compatible = "arm,cortex-a57";
460 enable-method = "spin-table";
461 cpu-release-addr = <0 0x20000000>;
466 compatible = "arm,cortex-a57";
468 enable-method = "spin-table";
469 cpu-release-addr = <0 0x20000000>;
474 compatible = "arm,cortex-a57";
476 enable-method = "spin-table";
477 cpu-release-addr = <0 0x20000000>;
482 compatible = "arm,cortex-a57";
484 enable-method = "spin-table";
485 cpu-release-addr = <0 0x20000000>;
490 compatible = "arm,cortex-a57";
492 enable-method = "spin-table";
493 cpu-release-addr = <0 0x20000000>;
498 compatible = "arm,cortex-a57";
500 enable-method = "spin-table";
501 cpu-release-addr = <0 0x20000000>;
506 compatible = "arm,cortex-a57";
508 enable-method = "spin-table";
509 cpu-release-addr = <0 0x20000000>;
514 compatible = "arm,cortex-a57";
516 enable-method = "spin-table";
517 cpu-release-addr = <0 0x20000000>;
522 compatible = "arm,cortex-a57";
524 enable-method = "spin-table";
525 cpu-release-addr = <0 0x20000000>;
530 compatible = "arm,cortex-a57";
532 enable-method = "spin-table";
533 cpu-release-addr = <0 0x20000000>;
538 compatible = "arm,cortex-a57";
540 enable-method = "spin-table";
541 cpu-release-addr = <0 0x20000000>;
546 compatible = "arm,cortex-a57";
548 enable-method = "spin-table";
549 cpu-release-addr = <0 0x20000000>;
554 compatible = "arm,cortex-a57";
556 enable-method = "spin-table";
557 cpu-release-addr = <0 0x20000000>;
562 compatible = "arm,cortex-a57";
564 enable-method = "spin-table";
565 cpu-release-addr = <0 0x20000000>;