RE: [PATCH] soc: imx-scu: Support module build

From: Aisheng Dong
Date: Fri Jun 19 2020 - 02:21:38 EST


> From: Arnd Bergmann <arnd@xxxxxxxx>
> Sent: Thursday, June 18, 2020 3:21 PM
>
> On Wed, Jun 17, 2020 at 11:41 AM Anson Huang <anson.huang@xxxxxxx>
> wrote:
>
> > > >
> > > > I'm ok with the change. But I'm curious how can this module be
> > > > autoloaded without MODULE_DEVICE_TABLE.
> > > > Have you tested if it can work?
> > > >
> > >
> > > I ONLY tested the manual insmod, if want to support auto load, may
> > > need some more change, will try it later and send out a V2 if needed.
> >
> > The further check shows that, if want to support auto load, the
> > platform device register needs to be done in somewhere else which is
> > built-in (in my test, I move it to clk-imx8qxp.c's probe), and also
> > need to add below module alias in this driver, because it has no device node in
> DT and no device table in driver.
> >
> > +MODULE_ALIAS("platform:imx-scu-soc");
> >
> > Since this driver has no device node in DT, and the target is to build
> > all SoC specific drivers as module, so the best way is to add a
> > virtual device node in DT in order to support auto load?
>
> I see that there is indeed a driver for the device node in
> drivers/firmware/imx/imx-scu.c, the only reason for this module using
> device_initcall() with a manual
> platform_device_register_simple() seems to be that we cannot have two
> platform drivers bind to the same device node.
>
> I think a cleaner way to handle this would be to just move the entire soc driver
> into the firmware driver and then remove the duplication.
>

Yes, sounds like a good idea to me.

Regards
Aisheng

> Arnd