bindings/arm/psci.yaml

1 # SPDX-License-Identifier: GPL-2.0
3 ---
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
10   - Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
15   processors") can be used by Linux to initiate various CPU-centric power
18   Issue A of the specification describes functions for CPU suspend, hotplug
21   Functions are invoked by trapping to the privilege level of the PSCI
23   in a manner similar to that specified by AAPCS:
25      r0       => 32-bit Function ID / return value
26     {r1 - r3}	=> Parameters
29   to #0.
40       - description:
41           For implementations complying to PSCI versions prior to 0.2.
44       - description:
45           For implementations complying to PSCI 0.2.
47           PSCI 0.2 support, but are permitted to be present for compatibility
52           - const: arm,psci-0.2
53           - const: arm,psci
55       - description:
56           For implementations complying to PSCI 1.0.
61           - const: arm,psci-1.0
62           - const: arm,psci-0.2
63           - const: arm,psci
67     $ref: /schemas/types.yaml#/definitions/string-array
69       - smc
71       - hvc
89   arm,psci-suspend-param:
92       power_state parameter to pass to the PSCI suspend call.
95       idle state nodes with entry-method property is set to "psci", as per
98       [1] Kernel documentation - ARM idle states bindings
99         Documentation/devicetree/bindings/cpu/idle-states.yaml
102   "^power-domain-":
103     $ref: /schemas/power/power-domain.yaml#
109       arrangement. This often, but not always, maps directly to the processor
113       For these cases, the definitions of the idle states for the CPUs and the
114       CPU topology, must conform to the binding in [3]. The idle states
115       themselves must conform to the binding in [4] and must specify the
116       arm,psci-suspend-param property.
118       It should also be noted that, in PSCI firmware v1.0 the OS-Initiated
119       (OSI) CPU suspend mode is introduced. Using a hierarchical representation
120       helps to implement support for OSI mode and OS implementations may choose
121       to mandate it.
123       [3] Documentation/devicetree/bindings/power/power-domain.yaml
124       [4] Documentation/devicetree/bindings/power/domain-idle-state.yaml
127   - compatible
128   - method
131   - if:
138         - cpu_off
139         - cpu_on
144   - |+
157   - |+
162       compatible      = "arm,psci-0.2";
167   - |+
173      * enabling firmware and hypervisors to support existing and new kernels.
179       compatible = "arm,psci-0.2", "arm,psci";
186   - |+
188     // Case 4: CPUs and CPU idle states described using the hierarchical model.
191       #size-cells = <0>;
192       #address-cells = <1>;
196         compatible = "arm,cortex-a53";
198         enable-method = "psci";
199         power-domains = <&CPU_PD0>;
200         power-domain-names = "psci";
205         compatible = "arm,cortex-a53";
207         enable-method = "psci";
208         power-domains = <&CPU_PD1>;
209         power-domain-names = "psci";
212       idle-states {
214         CPU_PWRDN: cpu-power-down {
215           compatible = "arm,idle-state";
216           arm,psci-suspend-param = <0x0000001>;
217           entry-latency-us = <10>;
218           exit-latency-us = <10>;
219           min-residency-us = <100>;
223       domain-idle-states {
225         CLUSTER_RET: cluster-retention {
226           compatible = "domain-idle-state";
227           arm,psci-suspend-param = <0x1000011>;
228           entry-latency-us = <500>;
229           exit-latency-us = <500>;
230           min-residency-us = <2000>;
233         CLUSTER_PWRDN: cluster-power-down {
234           compatible = "domain-idle-state";
235           arm,psci-suspend-param = <0x1000031>;
236           entry-latency-us = <2000>;
237           exit-latency-us = <2000>;
238           min-residency-us = <6000>;
244       compatible = "arm,psci-1.0";
247       CPU_PD0: power-domain-cpu0 {
248         #power-domain-cells = <0>;
249         domain-idle-states = <&CPU_PWRDN>;
250         power-domains = <&CLUSTER_PD>;
253       CPU_PD1: power-domain-cpu1 {
254         #power-domain-cells = <0>;
255         domain-idle-states =  <&CPU_PWRDN>;
256         power-domains = <&CLUSTER_PD>;
259       CLUSTER_PD: power-domain-cluster {
260         #power-domain-cells = <0>;
261         domain-idle-states = <&CLUSTER_RET>, <&CLUSTER_PWRDN>;