[RFC,v3,2/2] dt-bindings: cpufreq: Document Krait CPU Cache scaling

Commit Message

Christian Marangi Aug. 21, 2020, 2 p.m. UTC

Document dedicated Krait CPU Cache Scaling driver.

Signed-off-by: Ansuel Smith <[e-mail]>
---
 .../bindings/cpufreq/krait-cache-scale.yaml   | 79 +++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml

Comments

Rob Herring (Arm) Aug. 24, 2020, 5:28 p.m. UTC | #1

On Fri, 21 Aug 2020 16:00:21 +0200, Ansuel Smith wrote:
> Document dedicated Krait CPU Cache Scaling driver.
> 
> Signed-off-by: Ansuel Smith <[e-mail]>
> ---
>  .../bindings/cpufreq/krait-cache-scale.yaml   | 79 +++++++++++++++++++
>  1 file changed, 79 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml
> 


My bot found errors running 'make dt_binding_check' on your patch:

/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.example.dt.yaml: qcom-krait-cache: clocks:0:1: missing phandle tag in 4
	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.example.dt.yaml: qcom-krait-cache: clocks:0: [4294967295, 4] is too long
	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml


See https://patchwork.ozlabs.org/patch/1349260

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure dt-schema is up to date:

pip3 install git+https://github.com/devicetree-org/dt-schema.git@master --upgrade

Please check and re-submit.

Patch

diff --git a/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml b/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml
new file mode 100644
index 000000000000..f5f1c9b76656
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/krait-cache-scale.yaml
@@ -0,0 +1,79 @@ 
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/cpufreq/krait-cache-scale.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Krait Cpu Cache Frequency Scaling dedicated driver
+
+maintainers:
+  - Ansuel Smith <[e-mail]>
+
+description: |
+  This Scale the Krait CPU Cache Frequency and optionally voltage
+  when the Cpu Frequency is changed (using the cpufreq notifier).
+
+  Cache is scaled with the max frequency across all core and the cache
+  frequency will scale based on the configured threshold in the dts.
+
+  The cache thresholds can be set to 3+ frequency bin, idle, nominal and
+  high.
+
+properties:
+  compatible:
+    const: qcom,krait-cache
+
+  clocks:
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+    description: Phandle to the L2 CPU clock
+
+  clock-names:
+    const: "l2"
+
+  voltage-tolerance:
+    description: Same voltage tollerance of the Krait CPU
+
+  l2-cpufreq:
+    description: |
+      Threshold used by the driver to scale the L2 cache.
+      If the max CPU Frequency is more than the set frequency,
+      the driver will transition to the next frequency bin.
+      Value is in kHz
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 3
+    items:
+      - description: idle
+      - description: nominal
+      - description: high
+
+  l2-supply:
+    $ref: "/schemas/types.yaml#/definitions/phandle"
+    description: Phandle to the L2 regulator supply.
+
+  opp-table: true
+
+required:
+  - compatible
+  - clocks
+  - clock-names
+  - voltage-tolerance
+  - l2-cpufreq
+  - l2-supply
+
+examples:
+  - |
+    qcom-krait-cache {
+      compatible = "qcom,krait-cache";
+      clocks = <&kraitcc 4>;
+      clock-names = "l2";
+      voltage-tolerance = <5>;
+      l2-cpufreq = <384000 600000 1200000>;
+      l2-supply = <&smb208_s1a>;
+
+      operating-points = <
+        /* kHz    uV */
+        384000  1100000
+        1000000  1100000
+        1200000  1150000
+      >;
+    };