Re: [PATCH v5 02/15] dt: psci: Update DT bindings to support hierarchical PSCI states
From: Rob Herring <robh+dt@kernel.org>
Date: 2020-01-13 19:53:31
Also in:
linux-arm-msm, linux-pm
On Mon, Dec 30, 2019 at 8:44 AM Ulf Hansson [off-list ref] wrote:
Update PSCI DT bindings to allow to represent idle states for CPUs and the
CPU topology, by using a hierarchical layout. Primarily this is done by
re-using the existing DT bindings for PM domains [1] and for PM domain idle
states [2].
Let's also add an example into the document for the PSCI DT bindings, to
clearly show the new hierarchical based layout. The currently supported
flattened layout, is already described in the ARM idle states bindings [3],
so let's leave that as is.
[1] Documentation/devicetree/bindings/power/power_domain.txt
[2] Documentation/devicetree/bindings/power/domain-idle-state.txt
[3] Documentation/devicetree/bindings/arm/idle-states.txt
Co-developed-by: Lina Iyer <redacted>
Signed-off-by: Lina Iyer <redacted>
Reviewed-by: Sudeep Holla <redacted>
Signed-off-by: Ulf Hansson <redacted>
---
Changes in v5:
- None.
First I'm seeing this as the DT list was not copied. The example has
problems when running 'make dt_binding_check':
Documentation/devicetree/bindings/arm/psci.example.dt.yaml: cpu@0:
compatible: Additional items are not allowed ('arm,armv8' was
unexpected)
Documentation/devicetree/bindings/arm/psci.example.dt.yaml: cpu@0:
compatible: ['arm,cortex-a53', 'arm,armv8'] is too long
Documentation/devicetree/bindings/arm/psci.example.dt.yaml: cpu@1:
compatible: Additional items are not allowed ('arm,armv8' was
unexpected)
Documentation/devicetree/bindings/arm/psci.example.dt.yaml: cpu@1:
compatible: ['arm,cortex-a57', 'arm,armv8'] is too long
'arm,armv8' is only valid for s/w models.
Documentation/devicetree/bindings/arm/psci.example.dt.yaml:
idle-states: cluster-retention:compatible:0: 'arm,idle-state' was
expected
Documentation/devicetree/bindings/arm/psci.example.dt.yaml:
idle-states: cluster-power-down:compatible:0: 'arm,idle-state' was
expected
The last 2 are due to my conversion of the idle-states binding which
is in my tree now. Probably need to add 'domain-idle-state' as a
compatible at a minimum. It looks like domain-idle-state.txt is pretty
much the same as arm/idle-state.txt, so we should perhaps merge them.
There's some bigger issues though.
quoted hunk ↗ jump to hunk
--- .../devicetree/bindings/arm/cpus.yaml | 15 +++ .../devicetree/bindings/arm/psci.yaml | 104 ++++++++++++++++++ 2 files changed, 119 insertions(+)diff --git a/Documentation/devicetree/bindings/arm/cpus.yaml b/Documentation/devicetree/bindings/arm/cpus.yaml index c23c24ff7575..7a9c3ce2dbef 100644 --- a/Documentation/devicetree/bindings/arm/cpus.yaml +++ b/Documentation/devicetree/bindings/arm/cpus.yaml@@ -242,6 +242,21 @@ properties: where voltage is in V, frequency is in MHz. + power-domains: + $ref: '/schemas/types.yaml#/definitions/phandle-array' + description: + List of phandles and PM domain specifiers, as defined by bindings of the + PM domain provider (see also ../power_domain.txt). + + power-domain-names: + $ref: '/schemas/types.yaml#/definitions/string-array' + description: + A list of power domain name strings sorted in the same order as the + power-domains property. + + For PSCI based platforms, the name corresponding to the index of the PSCI + PM domain provider, must be "psci". + qcom,saw: $ref: '/schemas/types.yaml#/definitions/phandle' description: |diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml index 7abdf58b335e..8ef85420b2ab 100644 --- a/Documentation/devicetree/bindings/arm/psci.yaml +++ b/Documentation/devicetree/bindings/arm/psci.yaml@@ -102,6 +102,34 @@ properties: [1] Kernel documentation - ARM idle states bindings Documentation/devicetree/bindings/arm/idle-states.txt + "#power-domain-cells":
This is wrong because you are saying the /psci node should have these properties. You need to define the child nodes (at least a pattern you can match on) and put these properties there.
+ description: + The number of cells in a PM domain specifier as per binding in [3]. + Must be 0 as to represent a single PM domain. + + ARM systems can have multiple cores, sometimes in an hierarchical + arrangement. This often, but not always, maps directly to the processor + power topology of the system. Individual nodes in a topology have their + own specific power states and can be better represented hierarchically. + + For these cases, the definitions of the idle states for the CPUs and the + CPU topology, must conform to the binding in [3]. The idle states + themselves must conform to the binding in [4] and must specify the + arm,psci-suspend-param property. + + It should also be noted that, in PSCI firmware v1.0 the OS-Initiated + (OSI) CPU suspend mode is introduced. Using a hierarchical representation + helps to implement support for OSI mode and OS implementations may choose + to mandate it. + + [3] Documentation/devicetree/bindings/power/power_domain.txt + [4] Documentation/devicetree/bindings/power/domain-idle-state.txt + + power-domains: + $ref: '/schemas/types.yaml#/definitions/phandle-array' + description: + List of phandles and PM domain specifiers, as defined by bindings of the + PM domain provider.
A schema for 'domain-idle-states' property is missing.
quoted hunk ↗ jump to hunk
required: - compatible@@ -160,4 +188,80 @@ examples: cpu_on = <0x95c10002>; cpu_off = <0x95c10001>; }; + + - |+ + + // Case 4: CPUs and CPU idle states described using the hierarchical model. + + cpus { + #size-cells = <0>; + #address-cells = <1>; + + CPU0: cpu@0 { + device_type = "cpu"; + compatible = "arm,cortex-a53", "arm,armv8"; + reg = <0x0>; + enable-method = "psci"; + power-domains = <&CPU_PD0>; + power-domain-names = "psci"; + }; + + CPU1: cpu@1 { + device_type = "cpu"; + compatible = "arm,cortex-a57", "arm,armv8"; + reg = <0x100>; + enable-method = "psci"; + power-domains = <&CPU_PD1>; + power-domain-names = "psci"; + }; + + idle-states { + + CPU_PWRDN: cpu-power-down { + compatible = "arm,idle-state"; + arm,psci-suspend-param = <0x0000001>; + entry-latency-us = <10>; + exit-latency-us = <10>; + min-residency-us = <100>; + }; + + CLUSTER_RET: cluster-retention { + compatible = "domain-idle-state"; + arm,psci-suspend-param = <0x1000011>; + entry-latency-us = <500>; + exit-latency-us = <500>; + min-residency-us = <2000>; + }; + + CLUSTER_PWRDN: cluster-power-down { + compatible = "domain-idle-state"; + arm,psci-suspend-param = <0x1000031>; + entry-latency-us = <2000>; + exit-latency-us = <2000>; + min-residency-us = <6000>; + }; + }; + }; + + psci { + compatible = "arm,psci-1.0"; + method = "smc"; + + CPU_PD0: cpu-pd0 { + #power-domain-cells = <0>; + domain-idle-states = <&CPU_PWRDN>; + power-domains = <&CLUSTER_PD>; + }; + + CPU_PD1: cpu-pd1 { + #power-domain-cells = <0>; + domain-idle-states = <&CPU_PWRDN>; + power-domains = <&CLUSTER_PD>; + }; + + CLUSTER_PD: cluster-pd { + #power-domain-cells = <0>; + domain-idle-states = <&CLUSTER_RET>, <&CLUSTER_PWRDN>; + }; + }; ... --2.17.1
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