[PATCH] dt-bindings: arm: Convert PSCI binding to json-schema
From: Rob Herring
Date: Mon Jun 17 2019 - 16:29:41 EST
Convert the PSCI binding to use DT schema format.
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
Note that I didn't make cpu_suspend required for arm,psci as some
platforms didn't have that and the spec isn't clear if optional or
required. One board (artpec6-devboard.dts) also doesn't implement
cpu_off.
There's also 1 board (mt8173-evb.dts) that claims 0.1, 0.2, and 1.0
compatibility. I guess that's valid, but not really clear in the binding
doc. If we want to just allow any combination of versions, the schema
for compatible could be simplified a bit.
Documentation/arm64/booting.txt | 2 +-
.../devicetree/bindings/arm/arm-boards | 2 +-
.../devicetree/bindings/arm/idle-states.txt | 2 +-
.../devicetree/bindings/arm/psci.txt | 111 ------------
.../devicetree/bindings/arm/psci.yaml | 163 ++++++++++++++++++
.../translations/zh_CN/arm64/booting.txt | 2 +-
6 files changed, 167 insertions(+), 115 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/arm/psci.txt
create mode 100644 Documentation/devicetree/bindings/arm/psci.yaml
diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt
index fbab7e21d116..1a87dee739db 100644
--- a/Documentation/arm64/booting.txt
+++ b/Documentation/arm64/booting.txt
@@ -257,7 +257,7 @@ following manner:
processors") to bring CPUs into the kernel.
The device tree should contain a 'psci' node, as described in
- Documentation/devicetree/bindings/arm/psci.txt.
+ Documentation/devicetree/bindings/arm/psci.yaml.
- Secondary CPU general-purpose register settings
x0 = 0 (reserved for future use)
diff --git a/Documentation/devicetree/bindings/arm/arm-boards b/Documentation/devicetree/bindings/arm/arm-boards
index abff8d834a6a..6758ece324b1 100644
--- a/Documentation/devicetree/bindings/arm/arm-boards
+++ b/Documentation/devicetree/bindings/arm/arm-boards
@@ -197,7 +197,7 @@ Required nodes:
The description for the board must include:
- a "psci" node describing the boot method used for the secondary CPUs.
A detailed description of the bindings used for "psci" nodes is present
- in the psci.txt file.
+ in the psci.yaml file.
- a "cpus" node describing the available cores and their associated
"enable-method"s. For more details see cpus.txt file.
diff --git a/Documentation/devicetree/bindings/arm/idle-states.txt b/Documentation/devicetree/bindings/arm/idle-states.txt
index 3bdbe675b9e6..326f29b270ad 100644
--- a/Documentation/devicetree/bindings/arm/idle-states.txt
+++ b/Documentation/devicetree/bindings/arm/idle-states.txt
@@ -691,7 +691,7 @@ cpus {
Documentation/devicetree/bindings/arm/cpus.yaml
[2] ARM Linux Kernel documentation - PSCI bindings
- Documentation/devicetree/bindings/arm/psci.txt
+ Documentation/devicetree/bindings/arm/psci.yaml
[3] ARM Server Base System Architecture (SBSA)
http://infocenter.arm.com/help/index.jsp
diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt
deleted file mode 100644
index a2c4f1d52492..000000000000
--- a/Documentation/devicetree/bindings/arm/psci.txt
+++ /dev/null
@@ -1,111 +0,0 @@
-* Power State Coordination Interface (PSCI)
-
-Firmware implementing the PSCI functions described in ARM document number
-ARM DEN 0022A ("Power State Coordination Interface System Software on ARM
-processors") can be used by Linux to initiate various CPU-centric power
-operations.
-
-Issue A of the specification describes functions for CPU suspend, hotplug
-and migration of secure software.
-
-Functions are invoked by trapping to the privilege level of the PSCI
-firmware (specified as part of the binding below) and passing arguments
-in a manner similar to that specified by AAPCS:
-
- r0 => 32-bit Function ID / return value
- {r1 - r3} => Parameters
-
-Note that the immediate field of the trapping instruction must be set
-to #0.
-
-
-Main node required properties:
-
- - compatible : should contain at least one of:
-
- * "arm,psci" : For implementations complying to PSCI versions prior
- to 0.2.
- For these cases function IDs must be provided.
-
- * "arm,psci-0.2" : For implementations complying to PSCI 0.2.
- Function IDs are not required and should be ignored by
- an OS with PSCI 0.2 support, but are permitted to be
- present for compatibility with existing software when
- "arm,psci" is later in the compatible list.
-
- * "arm,psci-1.0" : For implementations complying to PSCI 1.0.
- PSCI 1.0 is backward compatible with PSCI 0.2 with
- minor specification updates, as defined in the PSCI
- specification[2].
-
- - method : The method of calling the PSCI firmware. Permitted
- values are:
-
- "smc" : SMC #0, with the register assignments specified
- in this binding.
-
- "hvc" : HVC #0, with the register assignments specified
- in this binding.
-
-Main node optional properties:
-
- - cpu_suspend : Function ID for CPU_SUSPEND operation
-
- - cpu_off : Function ID for CPU_OFF operation
-
- - cpu_on : Function ID for CPU_ON operation
-
- - migrate : Function ID for MIGRATE operation
-
-Device tree nodes that require usage of PSCI CPU_SUSPEND function (ie idle
-state nodes, as per bindings in [1]) must specify the following properties:
-
-- arm,psci-suspend-param
- Usage: Required for state nodes[1] if the corresponding
- idle-states node entry-method property is set
- to "psci".
- Value type: <u32>
- Definition: power_state parameter to pass to the PSCI
- suspend call.
-
-Example:
-
-Case 1: PSCI v0.1 only.
-
- psci {
- compatible = "arm,psci";
- method = "smc";
- cpu_suspend = <0x95c10000>;
- cpu_off = <0x95c10001>;
- cpu_on = <0x95c10002>;
- migrate = <0x95c10003>;
- };
-
-Case 2: PSCI v0.2 only
-
- psci {
- compatible = "arm,psci-0.2";
- method = "smc";
- };
-
-Case 3: PSCI v0.2 and PSCI v0.1.
-
- A DTB may provide IDs for use by kernels without PSCI 0.2 support,
- enabling firmware and hypervisors to support existing and new kernels.
- These IDs will be ignored by kernels with PSCI 0.2 support, which will
- use the standard PSCI 0.2 IDs exclusively.
-
- psci {
- compatible = "arm,psci-0.2", "arm,psci";
- method = "hvc";
-
- cpu_on = < arbitrary value >;
- cpu_off = < arbitrary value >;
-
- ...
- };
-
-[1] Kernel documentation - ARM idle states bindings
- Documentation/devicetree/bindings/arm/idle-states.txt
-[2] Power State Coordination Interface (PSCI) specification
- http://infocenter.arm.com/help/topic/com.arm.doc.den0022c/DEN0022C_Power_State_Coordination_Interface.pdf
diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml
new file mode 100644
index 000000000000..7abdf58b335e
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/psci.yaml
@@ -0,0 +1,163 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/psci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Power State Coordination Interface (PSCI)
+
+maintainers:
+ - Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
+
+description: |+
+ Firmware implementing the PSCI functions described in ARM document number
+ ARM DEN 0022A ("Power State Coordination Interface System Software on ARM
+ processors") can be used by Linux to initiate various CPU-centric power
+ operations.
+
+ Issue A of the specification describes functions for CPU suspend, hotplug
+ and migration of secure software.
+
+ Functions are invoked by trapping to the privilege level of the PSCI
+ firmware (specified as part of the binding below) and passing arguments
+ in a manner similar to that specified by AAPCS:
+
+ r0 => 32-bit Function ID / return value
+ {r1 - r3} => Parameters
+
+ Note that the immediate field of the trapping instruction must be set
+ to #0.
+
+ [2] Power State Coordination Interface (PSCI) specification
+ http://infocenter.arm.com/help/topic/com.arm.doc.den0022c/DEN0022C_Power_State_Coordination_Interface.pdf
+
+properties:
+ compatible:
+ oneOf:
+ - description:
+ For implementations complying to PSCI versions prior to 0.2.
+ const: arm,psci
+
+ - description:
+ For implementations complying to PSCI 0.2.
+ const: arm,psci-0.2
+
+ - description:
+ For implementations complying to PSCI 0.2.
+ Function IDs are not required and should be ignored by an OS with
+ PSCI 0.2 support, but are permitted to be present for compatibility
+ with existing software when "arm,psci" is later in the compatible
+ list.
+ items:
+ - const: arm,psci-0.2
+ - const: arm,psci
+
+ - description:
+ For implementations complying to PSCI 1.0.
+ const: arm,psci-1.0
+
+ - description:
+ For implementations complying to PSCI 1.0.
+ PSCI 1.0 is backward compatible with PSCI 0.2 with minor
+ specification updates, as defined in the PSCI specification[2].
+ items:
+ - const: arm,psci-1.0
+ - const: arm,psci-0.2
+
+ method:
+ description: The method of calling the PSCI firmware.
+ allOf:
+ - $ref: /schemas/types.yaml#/definitions/string-array
+ - enum:
+ # SMC #0, with the register assignments specified in this binding.
+ - smc
+ # HVC #0, with the register assignments specified in this binding.
+ - hvc
+
+ cpu_suspend:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Function ID for CPU_SUSPEND operation
+
+ cpu_off:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Function ID for CPU_OFF operation
+
+ cpu_on:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Function ID for CPU_ON operation
+
+ migrate:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Function ID for MIGRATE operation
+
+ arm,psci-suspend-param:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ power_state parameter to pass to the PSCI suspend call.
+
+ Device tree nodes that require usage of PSCI CPU_SUSPEND function (ie
+ idle state nodes with entry-method property is set to "psci", as per
+ bindings in [1]) must specify this property.
+
+ [1] Kernel documentation - ARM idle states bindings
+ Documentation/devicetree/bindings/arm/idle-states.txt
+
+
+required:
+ - compatible
+ - method
+
+allOf:
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: arm,psci
+ then:
+ required:
+ - cpu_off
+ - cpu_on
+
+examples:
+ - |+
+
+ // Case 1: PSCI v0.1 only.
+
+ psci {
+ compatible = "arm,psci";
+ method = "smc";
+ cpu_suspend = <0x95c10000>;
+ cpu_off = <0x95c10001>;
+ cpu_on = <0x95c10002>;
+ migrate = <0x95c10003>;
+ };
+
+ - |+
+
+ // Case 2: PSCI v0.2 only
+
+ psci {
+ compatible = "arm,psci-0.2";
+ method = "smc";
+ };
+
+
+ - |+
+
+ // Case 3: PSCI v0.2 and PSCI v0.1.
+
+ /*
+ * A DTB may provide IDs for use by kernels without PSCI 0.2 support,
+ * enabling firmware and hypervisors to support existing and new kernels.
+ * These IDs will be ignored by kernels with PSCI 0.2 support, which will
+ * use the standard PSCI 0.2 IDs exclusively.
+ */
+
+ psci {
+ compatible = "arm,psci-0.2", "arm,psci";
+ method = "hvc";
+
+ cpu_on = <0x95c10002>;
+ cpu_off = <0x95c10001>;
+ };
+...
diff --git a/Documentation/translations/zh_CN/arm64/booting.txt b/Documentation/translations/zh_CN/arm64/booting.txt
index c1dd968c5ee9..c84f2accb173 100644
--- a/Documentation/translations/zh_CN/arm64/booting.txt
+++ b/Documentation/translations/zh_CN/arm64/booting.txt
@@ -236,7 +236,7 @@ AArch64 åæååæææäèèåäçïåæåæäçäåçå
*èèæ: ARM DEN 0022A åææå ARM DEN 0022Cã
èåæåéååää âpsciâ èçïèåèääææï
- Documentation/devicetree/bindings/arm/psci.txt
+ Documentation/devicetree/bindings/arm/psci.yaml
- èå CPU éçåååèç
--
2.20.1