Re: [PATCH v1 2/6] device property: Add fwnode_property_match_property_string()

Jonathan Cameron
2023-08-28T18:01:45Z

On Thu, 10 Aug 2023 16:26:54 +0300
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> On Wed, Aug 09, 2023 at 06:59:44PM +0100, Jonathan Cameron wrote:
> > On Tue, 8 Aug 2023 19:27:56 +0300
> > Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
>
> ...
>
> > > +int fwnode_property_match_property_string(const struct fwnode_handle *fwnode,
> > > + const char *propname, const char * const *array, size_t n)
> >
> > Hi Andy,
> >
> > Whilst I'm not 100% sold on adding ever increasing complexity to what we
> > match, this one feels like a common enough thing to be worth providing.
>
> Yep, that's why I considered it's good to add (and because of new comers).
>
> > Looking at the usecases I wonder if it would be better to pass in
> > an unsigned int *ret which is only updated on a match?
>
> So the question is here are we going to match (pun intended) the prototype to
> the device_property_match*() family of functions or to device_property_read_*()
> one. If the latter, this has to be renamed, but then it probably will contradict
> the semantics as we are _matching_ against something and not just _reading_
> something.
>
> That said, do you agree that current implementation is (slightly) better from
> these aspects? Anyway, look at the below.
>
> > That way the common properties approach of not checking the return value
> > if we have an optional property would apply.
> >
> > e.g. patch 3
>
> Only?
I didn't look further :)

>
> > would end up with a block that looks like:
> >
> > st->input_mode = ADMV1014_IQ_MODE;
> > device_property_match_property_string(&spi->dev, "adi,input-mode",
> > input_mode_names,
> > ARRAY_SIZE(input_mode_names),
> > &st->input_mode);
> >
> > Only neat and tidy if the thing being optionally read into is an unsigned int
> > though (otherwise you still need a local variable)
>
> We also can have a hybrid variant, returning in both sides
>
> int device_property_match_property_string(..., size_t *index)
> {
> if (index)
> *index = ret;
> return ret;
> }
>
> (also note the correct return type as it has to match to @n).
>
> Would it be still okay or too over engineered?
>
Probably over engineered....

Lets stick to what you have. If various firmware folk are happy with
the new function that's fine by me. Rafael?

Jonathan