Re: [PATCH 6/6] dt-bindings: hwmon: jedec,jc42: add nxp,se97b

[Guenter Roeck <linux@roeck-us.net>]

On 10/8/21 1:00 AM, Krzysztof Kozlowski wrote:
> On 24/09/2021 13:51, Guenter Roeck wrote:
>> On Fri, Sep 24, 2021 at 08:57:44AM +0200, Krzysztof Kozlowski wrote:
>>> On 23/09/2021 23:16, Rob Herring wrote:
>>>> On Mon, Sep 20, 2021 at 08:21:14PM +0200, Krzysztof Kozlowski wrote:
>>>>> Document bindings for NXP SE97B, a DDR memory module temperature sensor
>>>>> with integrated SPD and EEPROM via Atmel's AT24 interface.
>>>>>
>>>>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
>>>>> ---
>>>>>   Documentation/devicetree/bindings/hwmon/jedec,jc42.yaml | 9 +++++++++
>>>>>   1 file changed, 9 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/hwmon/jedec,jc42.yaml b/Documentation/devicetree/bindings/hwmon/jedec,jc42.yaml
>>>>> index a7bb4e3a1c46..0e49b3901161 100644
>>>>> --- a/Documentation/devicetree/bindings/hwmon/jedec,jc42.yaml
>>>>> +++ b/Documentation/devicetree/bindings/hwmon/jedec,jc42.yaml
>>>>> @@ -10,6 +10,14 @@ maintainers:
>>>>>     - Jean Delvare <jdelvare@suse.com>
>>>>>     - Guenter Roeck <linux@roeck-us.net>
>>>>>   
>>>>> +select:
>>>>> +  properties:
>>>>> +    compatible:
>>>>> +      const: jedec,jc-42.4-temp
>>>>> +
>>>>> +  required:
>>>>> +    - compatible
>>>>> +
>>>>
>>>> Is this supposed to be in the last patch? And why is it needed?
>>>
>>> Yes, this is here on purpose because of nxp,se97b which is sensor with
>>> at24-compatible EEPROM.
>>>
>>> arch/arm/boot/dts/at91-nattis-2-natte-2.dts:
>>> 169         temp@18 {
>>> 170                 compatible = "nxp,se97b", "jedec,jc-42.4-temp";
>>>
>>> 171                 reg = <0x18>;
>>> 172                 smbus-timeout-disable;
>>> 173         };
>>> 174
>>> 175         eeprom@50 {
>>> 176                 compatible = "nxp,se97b", "atmel,24c02";
>>
>> How would that be handled anyway ? Yes, the chip includes both a temperature
>> sensor and an eeprom, but this node should most definitely not instantiate as
>> temperature sensor.
>>
> 
> I am not sure if I understand the problem you are mentioning. You have
> two nods in DT, two different compatible sets and two difference
> devices. One eeprom and other one a temperature sensor.
> 

I didn't realize that the driver is supposed to bind to "jedec,jc-42.4-temp"
and that "nxp,se97b" is really informational.

Sorry for the confusion.

Guenter