Re: [PATCH RFT] driver core: faux: allow to set the firmware node for a faux device

[Bartosz Golaszewski]

On Fri, Mar 6, 2026 at 2:54 PM Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, Mar 06, 2026 at 02:45:56PM +0100, Bartosz Golaszewski wrote:
> > Add a new variant of faux_device_create() taking a firmware node handle
> > as argument and attaching it to the created faux device. This allows
> > users to define and read device properties using the standard property
> > accessors.
>
> Why would a faux device have firmware backing?  Doesn't that mean it
> should be a platform device?
>
> > While at it: order includes in faux.c alphabetically for easier
> > maintenance.
>
> Hint, that should be a separate patch, and is never something that I
> enforce or require in .c files I maintain :)
>
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
> > ---
> > Hi Shivendra et al!
> >
> > This patch is related to my response to your reboot-mode patch[1].
> >
> > You should be able to use the new function like:
> >
> >   faux_device_create_full("psci-reboot-mode", NULL, NULL, NULL, of_fwnode_handle(np));
>
> What is the fwnode handle here for?  Why is it required at all?  What
> resources are involved that would want this?
>

Shivendra creates a faux device that registers with the reboot-mode
subsystem which reads the reboot-mode definitions from devicetree. The
faux device needs to have the "reboot-mode" OF-node attached. In his
current proposal, Shivenda had to bypass faux device's probe() because
he can't have the fwnode attached before probe() is called.

Bartosz