Re: [PATCH linux dev-4.10 4/6] Documentation: dt-bindings: Add a generic PECI hwmon

From: Arnd Bergmann
Date: Wed Jan 10 2018 - 07:20:23 EST


On Tue, Jan 9, 2018 at 11:31 PM, Jae Hyun Yoo
<jae.hyun.yoo@xxxxxxxxxxxxxxx> wrote:
> This commit add a dt-bindings document for a generic PECI hwmon
> driver.
>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/hwmon/peci-hwmon.txt | 33 ++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/hwmon/peci-hwmon.txt
>
> diff --git a/Documentation/devicetree/bindings/hwmon/peci-hwmon.txt b/Documentation/devicetree/bindings/hwmon/peci-hwmon.txt
> new file mode 100644
> index 0000000..20b86f5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/peci-hwmon.txt
> @@ -0,0 +1,33 @@
> +* Generic PECI (Platform Environment Control Interface) hwmon driver.
> +
> +Dependency:
> +- This driver uses a PECI misc driver as a controller interface so one of PECI
> + misc drivers which provides compatible ioctls has to be enabled.

The binding should only explain how we describe the hardware in an
operating-system
independent way, but not talk about how an OS is supposed to implement those
drivers.

Having multiple drivers each provide an exported function is not possible
in Linux: it immediately breaks building an 'allyesconfig' kernel, and prevents
you from running the same kernel across multiple implementations, so that
has to be redesigned anyway.

> +Required properties:
> +- compatible: "peci-hwmon"
> +- cpu-id: Should contain CPU socket ID
> + - 0 ~ 7
> +
> +Optional properties:
> +- show-core: If this protperty is defined, core tmeperature attrubites will be

s/protperty/property/
s/tmeperature/temperature/
s/attrubites/attributes/

> + enumerated.
> +- dimm-nums: Should contain the number of DIMM slots that attached to each CPU
> + which is indicated by cpu-id.
> + 0 ~ 16 (default: 16)
> + In case of 0, DIMM temperature attrubites will not be enumerated.

Is this only an initial list that you expect to be extended in the
future, or is this
a complete list of sensors that can ever be connected to PECI?

Should this be PECI version specific?

Arnd