[PATCH v3 06/11] dt-bindings: power: Add apple,pmgr-pwrstate binding

From: Hector Martin
Date: Wed Nov 24 2021 - 02:35:26 EST


This syscon child node represents a single SoC device controlled by the
PMGR block. This layout allows us to declare all device power state
controls (power/clock gating and reset) in the device tree, including
dependencies, instead of hardcoding it into the driver. The register
layout is uniform.

Each pmgr-pwrstate node provides genpd and reset features, to be
consumed by downstream device nodes.

Future SoCs are expected to use backwards compatible registers, and the
"apple,pmgr-pwrstate" represents any such interfaces (possibly with
additional features gated by the more specific compatible), allowing
them to be bound without driver updates. If a backwards incompatible
change is introduced in future SoCs, it will require a new compatible,
such as "apple,pmgr-pwrstate-v2".

Reviewed-by: Mark Kettenis <kettenis@xxxxxxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
.../bindings/power/apple,pmgr-pwrstate.yaml | 71 +++++++++++++++++++
1 file changed, 71 insertions(+)
create mode 100644 Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml

diff --git a/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml b/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml
new file mode 100644
index 000000000000..5056d08b8261
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/apple,pmgr-pwrstate.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SoC PMGR Power States
+
+maintainers:
+ - Hector Martin <marcan@xxxxxxxxx>
+
+allOf:
+ - $ref: "power-domain.yaml#"
+
+description: |
+ Apple SoCs include PMGR blocks responsible for power management,
+ which can control various clocks, resets, power states, and
+ performance features. This binding describes the device power
+ state registers, which control power states and resets.
+
+ Each instance of a power controller within the PMGR syscon node
+ represents a generic power domain provider, as documented in
+ Documentation/devicetree/bindings/power/power-domain.yaml.
+ The provider controls a single SoC block. The power hierarchy is
+ represented via power-domains relationships between these nodes.
+
+ See Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
+ for the top-level PMGR node documentation.
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - apple,t8103-pmgr-pwrstate
+ - apple,t6000-pmgr-pwrstate
+ - const: apple,pmgr-pwrstate
+
+ reg:
+ maxItems: 1
+
+ "#power-domain-cells":
+ const: 0
+
+ "#reset-cells":
+ const: 0
+
+ power-domains:
+ description:
+ Reference to parent power domains. A domain may have multiple parents,
+ and all will be powered up when it is powered.
+ minItems: 1
+ maxItems: 8 # Arbitrary, should be enough
+
+ label:
+ description:
+ Specifies the name of the SoC domain being controlled. This is used to
+ name the power/reset domains.
+
+ apple,always-on:
+ description:
+ Forces this power domain to always be powered up.
+ type: boolean
+
+required:
+ - compatible
+ - reg
+ - "#power-domain-cells"
+ - "#reset-cells"
+ - label
+
+additionalProperties: false
--
2.33.0