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.
118 - arm,armv8 # Only for s/w models
153 - nvidia,tegra132-denver
154 - nvidia,tegra186-denver
155 - nvidia,tegra194-carmel
164 - $ref: '/schemas/types.yaml#/definitions/string'
166 # On ARM v8 64-bit this property is required
170 # On ARM 32-bit systems this property is optional
173 - allwinner,sun6i-a31
174 - allwinner,sun8i-a23
175 - allwinner,sun9i-a80-smp
176 - allwinner,sun8i-a83t-smp
178 - amlogic,meson8b-smp
181 - brcm,bcm11351-cpu-method
187 - marvell,armada-375-smp
188 - marvell,armada-380-smp
189 - marvell,armada-390-smp
190 - marvell,armada-xp-smp
191 - marvell,98dx3236-smp
193 - mediatek,mt6589-smp
194 - mediatek,mt81xx-tz-smp
199 - renesas,r9a06g032-smp
200 - rockchip,rk3036-smp
201 - rockchip,rk3066-smp
202 - socionext,milbeaut-m10v-smp
206 $ref: '/schemas/types.yaml#/definitions/uint64'
209 Required for systems that have an "enable-method"
210 property value of "spin-table".
211 On ARM v8 64-bit systems must be a two cell
212 property identifying a 64-bit zero-initialised
216 $ref: '/schemas/types.yaml#/definitions/phandle-array'
218 List of phandles to idle state nodes supported
219 by this cpu (see ./idle-states.txt).
222 $ref: '/schemas/types.yaml#/definitions/uint32'
224 u32 value representing CPU capacity (see ./cpu-capacity.txt) in
225 DMIPS/MHz, relative to highest capacity-dmips-mhz
228 dynamic-power-coefficient:
229 $ref: '/schemas/types.yaml#/definitions/uint32'
231 A u32 value that represents the running time dynamic
232 power coefficient in units of uW/MHz/V^2. The
233 coefficient can either be calculated from power
234 measurements or derived by analysis.
236 The dynamic power consumption of the CPU is
237 proportional to the square of the Voltage (V) and
238 the clock frequency (f). The coefficient is used to
239 calculate the dynamic power as below -
241 Pdyn = dynamic-power-coefficient * V^2 * f
243 where voltage is in V, frequency is in MHz.
246 $ref: '/schemas/types.yaml#/definitions/phandle'
248 Specifies the SAW* node associated with this CPU.
250 Required for systems that have an "enable-method" property
251 value of "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2"
253 * arm/msm/qcom,saw2.txt
256 $ref: '/schemas/types.yaml#/definitions/phandle'
258 Specifies the ACC* node associated with this CPU.
260 Required for systems that have an "enable-method" property
261 value of "qcom,kpss-acc-v1" or "qcom,kpss-acc-v2"
263 * arm/msm/qcom,kpss-acc.txt
266 $ref: '/schemas/types.yaml#/definitions/phandle'
268 Specifies the syscon node controlling the cpu core power domains.
270 Optional for systems that have an "enable-method"
271 property value of "rockchip,rk3066-smp"
272 While optional, it is the preferred way to get access to
273 the cpu-core power-domains.
281 rockchip,pmu: [enable-method]
287 #address-cells = <1>;
291 compatible = "arm,cortex-a15";
297 compatible = "arm,cortex-a15";
303 compatible = "arm,cortex-a7";
309 compatible = "arm,cortex-a7";
315 // Example 2 (Cortex-A8 uniprocessor 32-bit system):
318 #address-cells = <1>;
322 compatible = "arm,cortex-a8";
328 // Example 3 (ARM 926EJ-S uniprocessor 32-bit system):
331 #address-cells = <1>;
335 compatible = "arm,arm926ej-s";
341 // Example 4 (ARM Cortex-A57 64-bit system):
344 #address-cells = <2>;
348 compatible = "arm,cortex-a57";
350 enable-method = "spin-table";
351 cpu-release-addr = <0 0x20000000>;
356 compatible = "arm,cortex-a57";
358 enable-method = "spin-table";
359 cpu-release-addr = <0 0x20000000>;
364 compatible = "arm,cortex-a57";
366 enable-method = "spin-table";
367 cpu-release-addr = <0 0x20000000>;
372 compatible = "arm,cortex-a57";
374 enable-method = "spin-table";
375 cpu-release-addr = <0 0x20000000>;
380 compatible = "arm,cortex-a57";
382 enable-method = "spin-table";
383 cpu-release-addr = <0 0x20000000>;
388 compatible = "arm,cortex-a57";
390 enable-method = "spin-table";
391 cpu-release-addr = <0 0x20000000>;
396 compatible = "arm,cortex-a57";
398 enable-method = "spin-table";
399 cpu-release-addr = <0 0x20000000>;
404 compatible = "arm,cortex-a57";
406 enable-method = "spin-table";
407 cpu-release-addr = <0 0x20000000>;
412 compatible = "arm,cortex-a57";
414 enable-method = "spin-table";
415 cpu-release-addr = <0 0x20000000>;
420 compatible = "arm,cortex-a57";
422 enable-method = "spin-table";
423 cpu-release-addr = <0 0x20000000>;
428 compatible = "arm,cortex-a57";
430 enable-method = "spin-table";
431 cpu-release-addr = <0 0x20000000>;
436 compatible = "arm,cortex-a57";
438 enable-method = "spin-table";
439 cpu-release-addr = <0 0x20000000>;
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>;