On 7/10/21 12:21 AM, Bjorn Andersson wrote:

On Thu 08 Jul 07:06 CDT 2021, Thara Gopinath wrote:

quoted

Add dt binding documentation to describe Qualcomm
Limits Management Hardware node.

Signed-off-by: Thara Gopinath <redacted>
---
  .../devicetree/bindings/thermal/qcom-lmh.yaml | 100 ++++++++++++++++++
  1 file changed, 100 insertions(+)
  create mode 100644 Documentation/devicetree/bindings/thermal/qcom-lmh.yaml

diff --git a/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml b/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
new file mode 100644
index 000000000000..7f62bd3d543d
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml

@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2021 Linaro Ltd.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/thermal/qcom-lmh.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Limits Management Hardware(LMh)
+
+maintainers:
+  - Thara Gopinath <thara.gopinath@linaro.org>
+
+description:
+  Limits Management Hardware(LMh) is a hardware infrastructure on some
+  Qualcomm SoCs that can enforce temperature and current limits as
+  programmed by software for certain IPs like CPU.
+
+properties:
+  compatible:
+    enum:
+      - qcom,sdm845-lmh
+
+  reg:
+    items:
+      - description: core registers
+
+  interrupts:
+    maxItems: 1
+
+  '#interrupt-cells':
+    const: 1
+
+  interrupt-controller: true
+
+  qcom,lmh-cpu-id:
+    description:
+      CPU id of the first cpu in the LMh cluster
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  qcom,lmh-temperature-arm:
+    description:
+      An integer expressing temperature threshold in millicelsius at which
+      the LMh thermal FSM is engaged.

Do we know (by any public source) what "arm", "low" and "high" means
beyond that they somehow pokes the state machine?

Not from public documentation. I know what these thresholds means, 
atleast to some extent. Though I will never claim to be an expert in 
this! There is an error in description of qcom,lmh-temperature-low and 
qcom,lmh-temperature-high below. I copied
and forgot to change the description. I will fix it.

quoted

+    $ref: /schemas/types.yaml#/definitions/int32
+
+  qcom,lmh-temperature-low:
+    description:
+      An integer expressing temperature threshold in millicelsius at which
+      the LMh thermal FSM is engaged.
+    $ref: /schemas/types.yaml#/definitions/int32
+
+  qcom,lmh-temperature-high:
+    description:
+      An integer expressing temperature threshold in millicelsius at which
+      the LMh thermal FSM is engaged.
+    $ref: /schemas/types.yaml#/definitions/int32
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - #interrupt-cells
+  - interrupt-controller
+  - qcom,lmh-cpu-id
+  - qcom,lmh-temperature-arm
+  - qcom,lmh-temperature-low
+  - qcom,lmh-temperature-high
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/qcom,rpmh.h>
+    #include <dt-bindings/interconnect/qcom,sdm845.h>

I don't see why you need qcom,rpmh.h or the interconnect include in this
example.

I could have sworn make dt-bindings check failed. But maybe only The 
first include is needed. I will remove the other two.

quoted

+
+    lmh_cluster1: lmh@17d70800 {
+      compatible = "qcom,sdm845-lmh";
+      reg = <0 0x17d70800 0 0x401>;

#address- and #size-cells are 1 in the wrapper that validates the
examples, so drop the two zeros.

Ok.

quoted

+      interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
+      qcom,lmh-cpu-id = <0x4>;
+      qcom,lmh-temperature-arm = <65000>;
+      qcom,lmh-temperature-low = <94500>;
+      qcom,lmh-temperature-high = <95000>;
+      interrupt-controller;
+      #interrupt-cells = <1>;
+    };
+  - |

This is a different example from the one above, if you intended that,
don't you need the #include of arm-gic.h here as well?

Again make dt-bindings check did not fail. It is a different example.
So I am not sure of the norm here. Is one example good enough ?

Regards,
Bjorn

quoted

+    lmh_cluster0: lmh@17d78800 {
+      compatible = "qcom,sdm845-lmh";
+      reg = <0 0x17d78800 0 0x401>;
+      interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
+      qcom,lmh-cpu-id = <0x0>;
+      qcom,lmh-temperature-arm = <65000>;
+      qcom,lmh-temperature-low = <94500>;
+      qcom,lmh-temperature-high = <95000>;
+      interrupt-controller;
+      #interrupt-cells = <1>;
+    };
+  - |
-- 
2.25.1

-- 
Warm Regards
Thara (She/Her/Hers)