Re: Implementation of fwnode_operations :: device_get_match_data() for software nodes?

Andy Shevchenko
2023-02-27T22:27:04Z

On Thu, Feb 23, 2023 at 10:37:13PM +0200, Vladimir Oltean wrote:
> Hi,
>
> I have a need to instantiate a driver written for OF which calls
> device_get_match_data(dev) to get various information based on the
> compatible string.
>
> I am creating a software node based on the following properties:
>
> struct property_entry props[2] = {
> PROPERTY_ENTRY_STRING("compatible", compatible),
> {},
> };
>
> (I see I'm not the only one doing this, some drivers/platform/x86/x86-android-tablets.c
> and drivers/platform/chrome/chromeos_laptop.c also do it)
>
> and the driver in question does begin to probe, but its match_data is
> NULL, because the operation from the title isn't implemented for
> software nodes. So probing ultimately fails.
>
> Is there some sort or reason why this doesn't exist, other than a lack
> of need?
>
> Can someone please help me with an implementation of this feature?

I believe that there are few reasons for that:
1) (besides that what Heikki mentioned);
2) the software nodes only for quirks, seems you are trying to implement
something that should have to be implemented as proper DT / ACPI device node.

Can you elaborate why do you need that (as you see no other board file requires
this)?

--
With Best Regards,
Andy Shevchenko