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
174 - nvidia,tegra132-denver
175 - nvidia,tegra186-denver
176 - nvidia,tegra194-carmel
195 $ref: '/schemas/types.yaml#/definitions/string'
197 # On ARM v8 64-bit this property is required
201 # On ARM 32-bit systems this property is optional
204 - allwinner,sun6i-a31
205 - allwinner,sun8i-a23
206 - allwinner,sun9i-a80-smp
207 - allwinner,sun8i-a83t-smp
209 - amlogic,meson8b-smp
212 - brcm,bcm11351-cpu-method
218 - marvell,armada-375-smp
219 - marvell,armada-380-smp
220 - marvell,armada-390-smp
221 - marvell,armada-xp-smp
222 - marvell,98dx3236-smp
224 - mediatek,mt6589-smp
225 - mediatek,mt81xx-tz-smp
231 # Only valid on ARM 32-bit, see above for ARM v8 64-bit
234 - renesas,r9a06g032-smp
235 - rockchip,rk3036-smp
236 - rockchip,rk3066-smp
237 - socionext,milbeaut-m10v-smp
244 - $ref: '/schemas/types.yaml#/definitions/uint32'
245 - $ref: '/schemas/types.yaml#/definitions/uint64'
247 The DT specification defines this as 64-bit always, but some 32-bit Arm
248 systems have used a 32-bit value which must be supported.
249 Required for systems that have an "enable-method"
250 property value of "spin-table".
253 $ref: '/schemas/types.yaml#/definitions/phandle-array'
257 List of phandles to idle state nodes supported
258 by this cpu (see ./idle-states.yaml).
262 u32 value representing CPU capacity (see ../cpu/cpu-capacity.txt) in
263 DMIPS/MHz, relative to highest capacity-dmips-mhz
266 cci-control-port: true
268 dynamic-power-coefficient:
269 $ref: '/schemas/types.yaml#/definitions/uint32'
271 A u32 value that represents the running time dynamic
272 power coefficient in units of uW/MHz/V^2. The
273 coefficient can either be calculated from power
274 measurements or derived by analysis.
276 The dynamic power consumption of the CPU is
277 proportional to the square of the Voltage (V) and
278 the clock frequency (f). The coefficient is used to
279 calculate the dynamic power as below -
281 Pdyn = dynamic-power-coefficient * V^2 * f
283 where voltage is in V, frequency is in MHz.
288 List of phandles and performance domain specifiers, as defined by
289 bindings of the performance domain provider. See also
290 dvfs/performance-domain.yaml.
294 List of phandles and PM domain specifiers, as defined by bindings of the
295 PM domain provider (see also ../power_domain.txt).
299 A list of power domain name strings sorted in the same order as the
300 power-domains property.
302 For PSCI based platforms, the name corresponding to the index of the PSCI
303 PM domain provider, must be "psci".
306 $ref: '/schemas/types.yaml#/definitions/phandle'
308 Specifies the SAW* node associated with this CPU.
310 Required for systems that have an "enable-method" property
311 value of "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2"
313 * arm/msm/qcom,saw2.txt
316 $ref: '/schemas/types.yaml#/definitions/phandle'
318 Specifies the ACC* node associated with this CPU.
320 Required for systems that have an "enable-method" property
321 value of "qcom,kpss-acc-v1", "qcom,kpss-acc-v2", "qcom,msm8226-smp" or
324 * arm/msm/qcom,kpss-acc.txt
327 $ref: '/schemas/types.yaml#/definitions/phandle'
329 Specifies the syscon node controlling the cpu core power domains.
331 Optional for systems that have an "enable-method"
332 property value of "rockchip,rk3066-smp"
333 While optional, it is the preferred way to get access to
334 the cpu-core power-domains.
337 $ref: '/schemas/types.yaml#/definitions/uint32'
339 Required for systems that have an "enable-method" property value of
340 "brcm,bcm11351-cpu-method", "brcm,bcm23550" or "brcm,bcm-nsp-smp".
342 This includes the following SoCs: |
343 BCM11130, BCM11140, BCM11351, BCM28145, BCM28155, BCM21664, BCM23550
344 BCM58522, BCM58525, BCM58535, BCM58622, BCM58623, BCM58625, BCM88312
346 The secondary-boot-reg property is a u32 value that specifies the
347 physical address of the register used to request the ROM holding pen
348 code release a secondary CPU. The value written to the register is
349 formed by encoding the target CPU id into the low bits of the
350 physical start address it should jump to.
353 # If the enable-method property contains one of those values
358 - brcm,bcm11351-cpu-method
361 # and if enable-method is present
375 rockchip,pmu: [enable-method]
377 additionalProperties: true
383 #address-cells = <1>;
387 compatible = "arm,cortex-a15";
393 compatible = "arm,cortex-a15";
399 compatible = "arm,cortex-a7";
405 compatible = "arm,cortex-a7";
411 // Example 2 (Cortex-A8 uniprocessor 32-bit system):
414 #address-cells = <1>;
418 compatible = "arm,cortex-a8";
424 // Example 3 (ARM 926EJ-S uniprocessor 32-bit system):
427 #address-cells = <1>;
431 compatible = "arm,arm926ej-s";
437 // Example 4 (ARM Cortex-A57 64-bit system):
440 #address-cells = <2>;
444 compatible = "arm,cortex-a57";
446 enable-method = "spin-table";
447 cpu-release-addr = <0 0x20000000>;
452 compatible = "arm,cortex-a57";
454 enable-method = "spin-table";
455 cpu-release-addr = <0 0x20000000>;
460 compatible = "arm,cortex-a57";
462 enable-method = "spin-table";
463 cpu-release-addr = <0 0x20000000>;
468 compatible = "arm,cortex-a57";
470 enable-method = "spin-table";
471 cpu-release-addr = <0 0x20000000>;
476 compatible = "arm,cortex-a57";
478 enable-method = "spin-table";
479 cpu-release-addr = <0 0x20000000>;
484 compatible = "arm,cortex-a57";
486 enable-method = "spin-table";
487 cpu-release-addr = <0 0x20000000>;
492 compatible = "arm,cortex-a57";
494 enable-method = "spin-table";
495 cpu-release-addr = <0 0x20000000>;
500 compatible = "arm,cortex-a57";
502 enable-method = "spin-table";
503 cpu-release-addr = <0 0x20000000>;
508 compatible = "arm,cortex-a57";
510 enable-method = "spin-table";
511 cpu-release-addr = <0 0x20000000>;
516 compatible = "arm,cortex-a57";
518 enable-method = "spin-table";
519 cpu-release-addr = <0 0x20000000>;
524 compatible = "arm,cortex-a57";
526 enable-method = "spin-table";
527 cpu-release-addr = <0 0x20000000>;
532 compatible = "arm,cortex-a57";
534 enable-method = "spin-table";
535 cpu-release-addr = <0 0x20000000>;
540 compatible = "arm,cortex-a57";
542 enable-method = "spin-table";
543 cpu-release-addr = <0 0x20000000>;
548 compatible = "arm,cortex-a57";
550 enable-method = "spin-table";
551 cpu-release-addr = <0 0x20000000>;
556 compatible = "arm,cortex-a57";
558 enable-method = "spin-table";
559 cpu-release-addr = <0 0x20000000>;
564 compatible = "arm,cortex-a57";
566 enable-method = "spin-table";
567 cpu-release-addr = <0 0x20000000>;