[PATCH v6 4/5] dt-bindings: arm: add support for SCMI Regulators

From: Cristian Marussi
Date: Thu Nov 19 2020 - 14:12:08 EST


Add devicetree bindings to support regulators based on SCMI Voltage
Domain Protocol.

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
---
v3 --> v4
- added list of supported Regulator bindings.
v2 --> v3
- avoid awkard examples based on _cpu/_gpu regulators
v1 --> v2
- removed any reference to negative voltages
---
.../devicetree/bindings/arm/arm,scmi.txt | 43 +++++++++++++++++++
1 file changed, 43 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt b/Documentation/devicetree/bindings/arm/arm,scmi.txt
index 55deb68230eb..6e011ca97079 100644
--- a/Documentation/devicetree/bindings/arm/arm,scmi.txt
+++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt
@@ -62,6 +62,29 @@ Required properties:
- #power-domain-cells : Should be 1. Contains the device or the power
domain ID value used by SCMI commands.

+Regulator bindings for the SCMI Regulator based on SCMI Message Protocol
+------------------------------------------------------------
+An SCMI Regulator is permanently bound to a well defined SCMI Voltage Domain,
+and should be always positioned as a root regulator.
+It does not support any current operation.
+
+SCMI Regulators are grouped under a 'regulators' node which in turn is a child
+of the SCMI Voltage protocol node inside the desired SCMI instance node.
+
+This binding uses the common regulator binding[6] but, due to SCMI abstractions,
+supports only a subset of its properties as specified below amongst Optional
+properties.
+
+Required properties:
+ - reg : shall identify an existent SCMI Voltage Domain.
+
+Optional properties:
+ - regulator-name
+ - regulator-min-microvolt / regulator-max-microvolt
+ - regulator-always-on / regulator-boot-on
+ - regulator-max-step-microvolt
+ - regulator-coupled-with / regulator-coupled-max-spread
+
Sensor bindings for the sensors based on SCMI Message Protocol
--------------------------------------------------------------
SCMI provides an API to access the various sensors on the SoC.
@@ -105,6 +128,7 @@ Required sub-node properties:
[3] Documentation/devicetree/bindings/thermal/thermal*.yaml
[4] Documentation/devicetree/bindings/sram/sram.yaml
[5] Documentation/devicetree/bindings/reset/reset.txt
+[6] Documentation/devicetree/bindings/regulator/regulator.yaml

Example:

@@ -169,6 +193,25 @@ firmware {
reg = <0x16>;
#reset-cells = <1>;
};
+
+ scmi_voltage: protocol@17 {
+ reg = <0x17>;
+
+ regulators {
+ regulator_devX: regulator@0 {
+ reg = <0x0>;
+ regulator-max-microvolt = <3300000>;
+ };
+
+ regulator_devY: regulator@9 {
+ reg = <0x9>;
+ regulator-min-microvolt = <500000>;
+ regulator-max-microvolt = <4200000>;
+ };
+
+ ...
+ };
+ };
};
};

--
2.17.1