On 2/9/22 05:36, Agathe Porte wrote:
Add basic description of the tmp464 driver DT bindings.
Signed-off-by: Agathe Porte <agathe.porte@xxxxxxxxx>
---
.../devicetree/bindings/hwmon/ti,tmp464.yaml | 106 ++++++++++++++++++
1 file changed, 106 insertions(+)
create mode 100644 Documentation/devicetree/bindings/hwmon/ti,tmp464.yaml
diff --git a/Documentation/devicetree/bindings/hwmon/ti,tmp464.yaml b/Documentation/devicetree/bindings/hwmon/ti,tmp464.yaml
new file mode 100644
index 000000000000..aaee652c0067
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/ti,tmp464.yaml
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/ti,tmp464.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TMP464 temperature sensor
+
+maintainers:
+ - Guenter Roeck <linux@xxxxxxxxxxxx>
+
+description: |
+ ±0.0625°C Remote and Local temperature sensor
+ https://www.ti.com/lit/ds/symlink/tmp464.pdf
+
+properties:
+ compatible:
+ enum:
+ - ti,tmp464
+ reg:
+ maxItems: 1
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+patternProperties:
+ "^channel@([0-3])$":
+ type: object
+ description: |
+ Represents channels of the device and their specific configuration.
+
+ properties:
+ reg:
+ description: |
+ The channel number. 0 is local channel, 1-3 are remote channels
+ items:
+ minimum: 0
+ maximum: 3
The chip has 1 local and 4 remote channels.
+
+ label:
+ description: |
+ A descriptive name for this channel, like "ambient" or "psu".
+
+ ti,n-factor:
+ description: |
+ The value (two's complement) to be programmed in the channel specific N correction register.
+ For remote channels only.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ items:
+ minimum: 0
+ maximum: 255
+
This does not seem to match the implementation, which calls
of_property_read_s32() and accepts values from -128 .. 127.
It seems unlikely that 255 is interpreted as -1.
Hmm, is that a bug in the tmp421 driver ? I wonder if anyone
checked that, and if there is an official means to express
negative numbers in devicetree. I see other drivers use
of_property_read_s32(), but I did not find a clear explanation
how to describe negative numbers in devicetree files.
Also, I think other chip configuration properties need to be
described here as well for completeness.
- temperature offsets
- hysteresis
- temperature limits
- conversion rate
+ required:
+ - reg
+
+ additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ sensor@4b {
+ compatible = "ti,tmp464";
+ reg = <0x4b>;
+ };
+ };
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ sensor@4b {
+ compatible = "ti,tmp464";
+ reg = <0x4b>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ channel@0 {
+ reg = <0x0>;
+ ti,n-factor = <0x1>;
+ label = "local";
+ };
+
+ channel@1 {
+ reg = <0x1>;
+ ti,n-factor = <0x0>;
+ label = "somelabel";
+ };
+
+ channel@2 {
+ reg = <0x2>;
+ status = "disabled";
+ };
+ };
+ };
