Re: [PATCH] iio: stm32-dfsdm: Treat flags as booleans

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 13 Jun 2026 16:39:16 +0300
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Fri, Jun 12, 2026 at 04:51:50PM -0500, Rob Herring (Arm) wrote:
> > The "st,adc-alt-channel" and "st,filter0-sync" properties are
> > documented as boolean flags. The legacy parser read them as integer
> > cells, unlike the child-node parser which already checks only for
> > presence.
> > 
> > Use presence and boolean helpers so both parsers follow the binding and
> > the property type checker no longer reports the flags.  
> 
> For the patch
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
> 
> However one interesting remark below.
> 
> ...
> 
> > -	ret = of_property_read_u32_index(indio_dev->dev.of_node,
> > -					 "st,adc-alt-channel", chan_idx,
> > -					 &df_ch->alt_si);  
> 
> > +	df_ch->alt_si = of_property_present(indio_dev->dev.of_node,  
> 
> I believe it still has another (serious?) issue. We usually don't use indio_dev
> for device properties. It's not a device that is described in DT.
> It seems the only driver in IIO that does that. Note, I haven't conducted any
> deeper research, it might be (however I'm quite in doubt) that this is correct
> use and one device registers a few indio_dev:s.

It is curious.  The registration sequence in this driver is complex, but I'm not
seeing anything that sets the fwnode for the struct iio_dev->dev before calling
the init() callbacks that end up in this code.  It is set later by iio_device_register()
(iirc that has something to do with consumers turning up later).

St folk could you take a look at this and see what we are missing
if it does currently work?

For now I'll apply this patch but might need to drop it if a fix clashes
with it.

Thanks,

Jonathan



> 
> > +					    "st,adc-alt-channel");  
>