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#
7 title: ARM CPUs bindings
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
171 - nvidia,tegra132-denver
172 - nvidia,tegra186-denver
173 - nvidia,tegra194-carmel
188 $ref: '/schemas/types.yaml#/definitions/string'
190 # On ARM v8 64-bit this property is required
194 # On ARM 32-bit systems this property is optional
197 - allwinner,sun6i-a31
198 - allwinner,sun8i-a23
199 - allwinner,sun9i-a80-smp
200 - allwinner,sun8i-a83t-smp
202 - amlogic,meson8b-smp
205 - brcm,bcm11351-cpu-method
211 - marvell,armada-375-smp
212 - marvell,armada-380-smp
213 - marvell,armada-390-smp
214 - marvell,armada-xp-smp
215 - marvell,98dx3236-smp
217 - mediatek,mt6589-smp
218 - mediatek,mt81xx-tz-smp
223 # Only valid on ARM 32-bit, see above for ARM v8 64-bit
226 - renesas,r9a06g032-smp
227 - rockchip,rk3036-smp
228 - rockchip,rk3066-smp
229 - socionext,milbeaut-m10v-smp
235 $ref: '/schemas/types.yaml#/definitions/uint64'
238 Required for systems that have an "enable-method"
239 property value of "spin-table".
240 On ARM v8 64-bit systems must be a two cell
241 property identifying a 64-bit zero-initialised
245 $ref: '/schemas/types.yaml#/definitions/phandle-array'
247 List of phandles to idle state nodes supported
248 by this cpu (see ./idle-states.yaml).
252 u32 value representing CPU capacity (see ./cpu-capacity.txt) in
253 DMIPS/MHz, relative to highest capacity-dmips-mhz
256 cci-control-port: true
258 dynamic-power-coefficient:
259 $ref: '/schemas/types.yaml#/definitions/uint32'
261 A u32 value that represents the running time dynamic
262 power coefficient in units of uW/MHz/V^2. The
263 coefficient can either be calculated from power
264 measurements or derived by analysis.
266 The dynamic power consumption of the CPU is
267 proportional to the square of the Voltage (V) and
268 the clock frequency (f). The coefficient is used to
269 calculate the dynamic power as below -
271 Pdyn = dynamic-power-coefficient * V^2 * f
273 where voltage is in V, frequency is in MHz.
278 List of phandles and performance domain specifiers, as defined by
279 bindings of the performance domain provider. See also
280 dvfs/performance-domain.yaml.
284 List of phandles and PM domain specifiers, as defined by bindings of the
285 PM domain provider (see also ../power_domain.txt).
289 A list of power domain name strings sorted in the same order as the
290 power-domains property.
292 For PSCI based platforms, the name corresponding to the index of the PSCI
293 PM domain provider, must be "psci".
296 $ref: '/schemas/types.yaml#/definitions/phandle'
298 Specifies the SAW* node associated with this CPU.
300 Required for systems that have an "enable-method" property
301 value of "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2"
303 * arm/msm/qcom,saw2.txt
306 $ref: '/schemas/types.yaml#/definitions/phandle'
308 Specifies the ACC* node associated with this CPU.
310 Required for systems that have an "enable-method" property
311 value of "qcom,kpss-acc-v1", "qcom,kpss-acc-v2", "qcom,msm8226-smp" or
314 * arm/msm/qcom,kpss-acc.txt
317 $ref: '/schemas/types.yaml#/definitions/phandle'
319 Specifies the syscon node controlling the cpu core power domains.
321 Optional for systems that have an "enable-method"
322 property value of "rockchip,rk3066-smp"
323 While optional, it is the preferred way to get access to
324 the cpu-core power-domains.
327 $ref: '/schemas/types.yaml#/definitions/uint32'
329 Required for systems that have an "enable-method" property value of
330 "brcm,bcm11351-cpu-method", "brcm,bcm23550" or "brcm,bcm-nsp-smp".
332 This includes the following SoCs: |
333 BCM11130, BCM11140, BCM11351, BCM28145, BCM28155, BCM21664, BCM23550
334 BCM58522, BCM58525, BCM58535, BCM58622, BCM58623, BCM58625, BCM88312
336 The secondary-boot-reg property is a u32 value that specifies the
337 physical address of the register used to request the ROM holding pen
338 code release a secondary CPU. The value written to the register is
339 formed by encoding the target CPU id into the low bits of the
340 physical start address it should jump to.
343 # If the enable-method property contains one of those values
348 - brcm,bcm11351-cpu-method
351 # and if enable-method is present
365 rockchip,pmu: [enable-method]
367 additionalProperties: true
373 #address-cells = <1>;
377 compatible = "arm,cortex-a15";
383 compatible = "arm,cortex-a15";
389 compatible = "arm,cortex-a7";
395 compatible = "arm,cortex-a7";
401 // Example 2 (Cortex-A8 uniprocessor 32-bit system):
404 #address-cells = <1>;
408 compatible = "arm,cortex-a8";
414 // Example 3 (ARM 926EJ-S uniprocessor 32-bit system):
417 #address-cells = <1>;
421 compatible = "arm,arm926ej-s";
427 // Example 4 (ARM Cortex-A57 64-bit system):
430 #address-cells = <2>;
434 compatible = "arm,cortex-a57";
436 enable-method = "spin-table";
437 cpu-release-addr = <0 0x20000000>;
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>;