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
172 - nvidia,tegra132-denver
173 - nvidia,tegra186-denver
174 - nvidia,tegra194-carmel
191 $ref: '/schemas/types.yaml#/definitions/string'
193 # On ARM v8 64-bit this property is required
197 # On ARM 32-bit systems this property is optional
200 - allwinner,sun6i-a31
201 - allwinner,sun8i-a23
202 - allwinner,sun9i-a80-smp
203 - allwinner,sun8i-a83t-smp
205 - amlogic,meson8b-smp
208 - brcm,bcm11351-cpu-method
214 - marvell,armada-375-smp
215 - marvell,armada-380-smp
216 - marvell,armada-390-smp
217 - marvell,armada-xp-smp
218 - marvell,98dx3236-smp
220 - mediatek,mt6589-smp
221 - mediatek,mt81xx-tz-smp
227 # Only valid on ARM 32-bit, see above for ARM v8 64-bit
230 - renesas,r9a06g032-smp
231 - rockchip,rk3036-smp
232 - rockchip,rk3066-smp
233 - socionext,milbeaut-m10v-smp
240 - $ref: '/schemas/types.yaml#/definitions/uint32'
241 - $ref: '/schemas/types.yaml#/definitions/uint64'
243 The DT specification defines this as 64-bit always, but some 32-bit Arm
244 systems have used a 32-bit value which must be supported.
245 Required for systems that have an "enable-method"
246 property value of "spin-table".
249 $ref: '/schemas/types.yaml#/definitions/phandle-array'
253 List of phandles to idle state nodes supported
254 by this cpu (see ./idle-states.yaml).
258 u32 value representing CPU capacity (see ./cpu-capacity.txt) in
259 DMIPS/MHz, relative to highest capacity-dmips-mhz
262 cci-control-port: true
264 dynamic-power-coefficient:
265 $ref: '/schemas/types.yaml#/definitions/uint32'
267 A u32 value that represents the running time dynamic
268 power coefficient in units of uW/MHz/V^2. The
269 coefficient can either be calculated from power
270 measurements or derived by analysis.
272 The dynamic power consumption of the CPU is
273 proportional to the square of the Voltage (V) and
274 the clock frequency (f). The coefficient is used to
275 calculate the dynamic power as below -
277 Pdyn = dynamic-power-coefficient * V^2 * f
279 where voltage is in V, frequency is in MHz.
284 List of phandles and performance domain specifiers, as defined by
285 bindings of the performance domain provider. See also
286 dvfs/performance-domain.yaml.
290 List of phandles and PM domain specifiers, as defined by bindings of the
291 PM domain provider (see also ../power_domain.txt).
295 A list of power domain name strings sorted in the same order as the
296 power-domains property.
298 For PSCI based platforms, the name corresponding to the index of the PSCI
299 PM domain provider, must be "psci".
302 $ref: '/schemas/types.yaml#/definitions/phandle'
304 Specifies the SAW* node associated with this CPU.
306 Required for systems that have an "enable-method" property
307 value of "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2"
309 * arm/msm/qcom,saw2.txt
312 $ref: '/schemas/types.yaml#/definitions/phandle'
314 Specifies the ACC* node associated with this CPU.
316 Required for systems that have an "enable-method" property
317 value of "qcom,kpss-acc-v1", "qcom,kpss-acc-v2", "qcom,msm8226-smp" or
320 * arm/msm/qcom,kpss-acc.txt
323 $ref: '/schemas/types.yaml#/definitions/phandle'
325 Specifies the syscon node controlling the cpu core power domains.
327 Optional for systems that have an "enable-method"
328 property value of "rockchip,rk3066-smp"
329 While optional, it is the preferred way to get access to
330 the cpu-core power-domains.
333 $ref: '/schemas/types.yaml#/definitions/uint32'
335 Required for systems that have an "enable-method" property value of
336 "brcm,bcm11351-cpu-method", "brcm,bcm23550" or "brcm,bcm-nsp-smp".
338 This includes the following SoCs: |
339 BCM11130, BCM11140, BCM11351, BCM28145, BCM28155, BCM21664, BCM23550
340 BCM58522, BCM58525, BCM58535, BCM58622, BCM58623, BCM58625, BCM88312
342 The secondary-boot-reg property is a u32 value that specifies the
343 physical address of the register used to request the ROM holding pen
344 code release a secondary CPU. The value written to the register is
345 formed by encoding the target CPU id into the low bits of the
346 physical start address it should jump to.
349 # If the enable-method property contains one of those values
354 - brcm,bcm11351-cpu-method
357 # and if enable-method is present
371 rockchip,pmu: [enable-method]
373 additionalProperties: true
379 #address-cells = <1>;
383 compatible = "arm,cortex-a15";
389 compatible = "arm,cortex-a15";
395 compatible = "arm,cortex-a7";
401 compatible = "arm,cortex-a7";
407 // Example 2 (Cortex-A8 uniprocessor 32-bit system):
410 #address-cells = <1>;
414 compatible = "arm,cortex-a8";
420 // Example 3 (ARM 926EJ-S uniprocessor 32-bit system):
423 #address-cells = <1>;
427 compatible = "arm,arm926ej-s";
433 // Example 4 (ARM Cortex-A57 64-bit system):
436 #address-cells = <2>;
440 compatible = "arm,cortex-a57";
442 enable-method = "spin-table";
443 cpu-release-addr = <0 0x20000000>;
448 compatible = "arm,cortex-a57";
450 enable-method = "spin-table";
451 cpu-release-addr = <0 0x20000000>;
456 compatible = "arm,cortex-a57";
458 enable-method = "spin-table";
459 cpu-release-addr = <0 0x20000000>;
464 compatible = "arm,cortex-a57";
466 enable-method = "spin-table";
467 cpu-release-addr = <0 0x20000000>;
472 compatible = "arm,cortex-a57";
474 enable-method = "spin-table";
475 cpu-release-addr = <0 0x20000000>;
480 compatible = "arm,cortex-a57";
482 enable-method = "spin-table";
483 cpu-release-addr = <0 0x20000000>;
488 compatible = "arm,cortex-a57";
490 enable-method = "spin-table";
491 cpu-release-addr = <0 0x20000000>;
496 compatible = "arm,cortex-a57";
498 enable-method = "spin-table";
499 cpu-release-addr = <0 0x20000000>;
504 compatible = "arm,cortex-a57";
506 enable-method = "spin-table";
507 cpu-release-addr = <0 0x20000000>;
512 compatible = "arm,cortex-a57";
514 enable-method = "spin-table";
515 cpu-release-addr = <0 0x20000000>;
520 compatible = "arm,cortex-a57";
522 enable-method = "spin-table";
523 cpu-release-addr = <0 0x20000000>;
528 compatible = "arm,cortex-a57";
530 enable-method = "spin-table";
531 cpu-release-addr = <0 0x20000000>;
536 compatible = "arm,cortex-a57";
538 enable-method = "spin-table";
539 cpu-release-addr = <0 0x20000000>;
544 compatible = "arm,cortex-a57";
546 enable-method = "spin-table";
547 cpu-release-addr = <0 0x20000000>;
552 compatible = "arm,cortex-a57";
554 enable-method = "spin-table";
555 cpu-release-addr = <0 0x20000000>;
560 compatible = "arm,cortex-a57";
562 enable-method = "spin-table";
563 cpu-release-addr = <0 0x20000000>;