dt-bindings: power: Convert domain-idle-states bindings to json-schema

While converting to the json-schema, let's also take the opportunity to
further specify/clarify some more details about the DT binding.

For example, let's define the label where to put the states nodes, set a
pattern for nodename of the state nodes and finally add an example.

Fixes: a3f048b5424e ("dt: psci: Update DT bindings to support hierarchical PSCI states")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
[robh: drop type refs from standard unit properties]
Signed-off-by: Rob Herring <robh@kernel.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/power/domain-idle-state.yaml b/Documentation/devicetree/bindings/power/domain-idle-state.yaml
new file mode 100644
index 000000000000..dfba1af9abe5
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/domain-idle-state.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/domain-idle-state.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PM Domain Idle States binding description
+
+maintainers:
+  - Ulf Hansson <ulf.hansson@linaro.org>
+
+description:
+  A domain idle state node represents the state parameters that will be used to
+  select the state when there are no active components in the PM domain.
+
+properties:
+  $nodename:
+    const: domain-idle-states
+
+patternProperties:
+  "^(cpu|cluster|domain)-":
+    type: object
+    description:
+      Each state node represents a domain idle state description.
+
+    properties:
+      compatible:
+        const: domain-idle-state
+
+      entry-latency-us:
+        description:
+          The worst case latency in microseconds required to enter the idle
+          state. Note that, the exit-latency-us duration may be guaranteed only
+          after the entry-latency-us has passed.
+
+      exit-latency-us:
+        description:
+          The worst case latency in microseconds required to exit the idle
+          state.
+
+      min-residency-us:
+        description:
+          The minimum residency duration in microseconds after which the idle
+          state will yield power benefits, after overcoming the overhead while
+          entering the idle state.
+
+    required:
+      - compatible
+      - entry-latency-us
+      - exit-latency-us
+      - min-residency-us
+
+examples:
+  - |
+
+    domain-idle-states {
+      domain_retention: domain-retention {
+        compatible = "domain-idle-state";
+        entry-latency-us = <20>;
+        exit-latency-us = <40>;
+        min-residency-us = <80>;
+      };
+    };
+...