Re: [PATCH] dt-bindings: hwmon: Add nct7802 bindings
From: Guenter Roeck <linux@roeck-us.net>
Date: 2021-09-17 03:29:20
Also in:
linux-hwmon, lkml
On Thu, Sep 16, 2021 at 11:09:16PM -0400, Oskar Senft wrote:
Ok, I experimented with that and I think I'm starting to get an idea how the DT bindings YAML works.quoted
quoted
Yes, let's do that. I'd like us to keep the "sensors" subnode to have a clear association and differentiator to other sub-nodes such as "regulators". Open is if we can use "temperature-sensor@0" or if it would have to be a chip specific "ltd", but I think we can sort that out after suggesting an initial set of bindings to Rob.However, I found that when I use the name@x syntax, the schema validator also requires the use of a reg or ranges property. But then doing so requires to set the #address-cells and #size-cells properties, which - I think - makes things weird. So these two examples are options that validate: i2c { #address-cells = <1>; #size-cells = <0>; nct7802@28 { compatible = "nuvoton,nct7802"; reg = <0x28>; temperature-sensors { ltd { status = "disabled"; label = "mainboard temperature"; }; rtd1 { status = "okay"; label = "inlet temperature"; type = <4> /* thermistor */; }; }; }; }; or i2c { #address-cells = <1>; #size-cells = <0>; nct7802@28 { compatible = "nuvoton,nct7802"; reg = <0x28>; temperature-sensors { #address-cells = <1>; #size-cells = <0>; sensor@0 { reg = <0>; status = "disabled"; label = "mainboard temperature"; }; sensor@1 { reg = <1>; status = "okay"; label = "inlet temperature"; type = <4> /* thermistor */; }; }; }; }; In the second case we end up having to duplicate information, i.e. "sensor@1" and "reg = <1>". Also, I have not yet found a way to validate that the "@x" is identical to the "reg = <x>". I believe that this is just how it is in device trees, but I want to make sure this is what we want? Thoughts?
Comparing those two, I prefer the first option. Can you write that up in a yaml file to present to Rob ? If he doesn't like it, we can still suggest the second variant as an alternative. Thanks, Guenter