Re: [PATCH] iio: core: Use datasheet name as fallback for label

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Mon, Oct 27, 2025 at 02:43:27PM +0000, Jonathan Cameron wrote:
> On Mon, 27 Oct 2025 20:42:09 +0800
> Chen-Yu Tsai <wens@kernel.org> wrote:
> 
> > Some IIO drivers do not provide labels or extended names for their
> > channels. However they may provide datasheet names. axp20x-adc is
> > one such example.
> > 
> > Use the datasheet name as a fallback for the channel label. This mainly
> > benefits iio-hwmon by letting the produced hwmon sensors have more
> > meaningful names rather than in_voltageX.
> 
> I definitely don't want to have different behaviour for in kernel requests
> and for people reading the _label attributes.  
> https://elixir.bootlin.com/linux/v6.18-rc2/source/drivers/iio/industrialio-core.c#L1232
> would need modifying to allow for the sysfs attributes to be created.
> 
> In general I'm not sure I want to do this.  Datasheet names can be exceptionally
> obscure which is why we've kept them hidden from userspace.  At least dts writers
> tend to have those names on their circuit diagrams and tend to have datasheet access.
> 
> Let's see if anyone else has feedback on this suggestion over next week or so.

This is an ABI change without
1) proper documentation;
2) backward compatibility (i.e. there is no knob to opt-out the change, or make
it opt-in).

In this form is definitely NAK.

If you wish something like this, better to have a separate attribute. But the
problem maybe also that the same component (or 100% compatible one) made by
different vendors and have different datasheet names. This means that the new
attribute may still be ambiguous. Hence I see a little sense to have it, rather
better to have these links / names to be put in DT schema. At least there we
have different vendors and compatibility mappings.

-- 
With Best Regards,
Andy Shevchenko