Guenter Roeck 於 28/02/2022 10:54 pm 寫道:

On 2/28/22 02:37, Potin Lai wrote:

quoted

Add documentation of new properties for sample averaging in PMON_CONFIG
register.

New properties:
- adi,volt-curr-sample-average
- adi,power-sample-average

Signed-off-by: Potin Lai <redacted>

doc
---
  .../bindings/hwmon/adi,adm1275.yaml           | 39 +++++++++++++++++++
  1 file changed, 39 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml b/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
index 223393d7cafd..bc4206b257a8 100644
--- a/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml
+++ b/Documentation/devicetree/bindings/hwmon/adi,adm1275.yaml

@@ -37,6 +37,43 @@ properties:

      description:
        Shunt resistor value in micro-Ohm.
  +  adi,volt-curr-sample-average:
+    description: |
+      Number of samples to be used to report voltage and current values.
+      If the configured value is not a power of 2, sample averaging number
+      will be configured with smaller and closest power of 2.
+
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 128
+    default: 1
+
+  adi,power-sample-average:
+    description: |
+      Number of samples to be used to report power values.
+      If the configured value is not a power of 2, sample averaging number
+      will be configured with smaller and closest power of 2.
+

Both properties should only accept 1, 2, 4, 8, 16, 32, 64, and 128.

We accept non-exact numbers in sysfs attributes because we can not
expect the end users to know permitted values, but devicetree authors
should know what is acceptable. Valid values can be expressed here
easily with something like
    enum: [1, 2, 4, 8, 16, 32, 64, 128]

This can also be easily tested in the code by ensuring that
the devicetree property is in the range of 1..128 and has exactly
one bit set, such as
    if (!val || val > 128 || hweight32(val) != 1)
or with something like
    if (!val || val > 128 || BIT(__fls(val)) != val)

Guenter

Got it, will make the property value only allowed with listed values, and add check in drive code.


Thanks,

Potin

quoted

+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 128
+    default: 1
+
+if:
+  not:
+    properties:
+      compatible:
+        contains:
+          enum:
+          - adi,adm1272
+          - adi,adm1278
+          - adi,adm1293
+          - adi,adm1294
+then:
+  properties:
+    adi,power-sample-average:
+      description: This property is not allowed.
+
  required:
    - compatible
    - reg

@@ -53,5 +90,7 @@ examples:

              compatible = "adi,adm1272";
              reg = <0x10>;
              shunt-resistor-micro-ohms = <500>;
+            adi,volt-curr-sample-average = <128>;
+            adi,power-sample-average = <128>;
          };
      };