Re: hwmon: label vs temp%d_label

[Chris Packham]

On 3/04/24 10:22, Chris Packham wrote:
>
> On 3/04/24 09:59, Guenter Roeck wrote:
>> On Tue, Apr 02, 2024 at 08:24:37PM +0000, Chris Packham wrote:
>>> Hi Guenter, Jean,
>>>
>>> I've got a requirement to add some meaningful names to some hwmon
>>> sensors (LM75 specifically) so that we can provide some indication of
>>> where on a board the sensor is located (e.g. "Intake" vs "Exhaust" vs
>>> "Near that really hot chip").
>>>
>>> I see that the sysfs ABI documents both "label" for the chip and
>>> "temp[1-*]_label" (as well as similar fan and Vin attributes). The
>>> latter seem to be supported by the hwmon core but I don't see anything
>>> for the former (I'm struggling to find any driver that supports a
>>> chip-wide label).
>>>
>>> Assuming I want to have a label added in the device tree to a lm75 
>>> would
>>> something like the following be acceptable
>>>
>>>         sensor@48 {
>>>           compatible = "national,lm75";
>>>           reg = <0x48>;
>>>           label = "Intake";
>>>         };
>>>
>>> I'd then update the lm75 driver to grab that from the devicetree and 
>>> use
>>> it to provide the hwmon_temp_label attribute.
>>>
>> Have you tried just declaring the label property as you suggested above
>> in your system without doing anything else, and looked at the generated
>> sysfs attributes ?
>
> I have not. But in my defense I'm also using an older kernel LTS that 
> doesn't have commit e1c9d6d61ddf ("hwmon: Add "label" attribute"). But 
> now that I know it exists I can carry it as a local patch until we 
> next update.

Related is there an lm-sensors change that uses this attribute for 
display purposes?

I do have a couple of PRs open on the lm-sensors github project I'd like 
to see merged but given recent events this should absolutely not be 
construed as a criticism of anyone maintaining lm-sensors merely a query 
as to whether PRs are the right path for changes or if they should be 
sent to a mailing list somewhere.