Re: [EXT] Re: [PATCH v3 4/4] soc: imx8m: change to use platform driver

[Krzysztof Kozlowski]

On Wed, Nov 18, 2020 at 02:07:41PM +0000, Alice Guo wrote:
> 
> 
> > -----Original Message-----
> > From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> > Sent: 2020年11月18日 18:42
> > To: Alice Guo <alice.guo@xxxxxxx>
> > Cc: robh+dt@xxxxxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx;
> > dl-linux-imx <linux-imx@xxxxxxx>; Peng Fan <peng.fan@xxxxxxx>;
> > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > Subject: Re: [EXT] Re: [PATCH v3 4/4] soc: imx8m: change to use platform
> > driver
> > 
> > Caution: EXT Email
> > 
> > On Wed, Nov 18, 2020 at 10:28:47AM +0000, Alice Guo wrote:
> >  >
> > > > If it is properly explained and there is no other way then yes, you
> > > > could. Here, for old DTBs, I would prefer to use
> > > > of_platform_device_create() and bind to "soc" node (child of root).
> > > > This way you would always have device and exactly one entry point
> > > > for the probe.
> > > >
> > >
> > > static struct platform_driver imx8_soc_init_driver = {
> > >       .probe = imx8_soc_init_probe,
> > >       .driver = {
> > >               .name = "soc@0",
> > >       },
> > > };
> > > Can I use "soc@0" to match this driver? It will not use
> > > of_platform_device_create(). It will use of_find_property() to
> > > determine whether and nvmem-cells can be used. If there is no nvmem-cells,
> > it will use the old way, which supports old DTBS. There is no need to add new
> > compatible.
> > 
> > No, the soc@0 is not a proper name for the driver.
> 
> I have no good idea, please give suggestion. Should I still add new compatible?
> Should I still keep device_initcall? If use of_platform_device_create(), which
> node should I use?

I mentioned my idea in the email before - of_platform_device_create() to
bind to the soc node. This will have to be in the initcall, you don't
have a choice to avoid it, since there was no compatible before.

Best regards,
Krzysztof