Re: [PATCH v8 08/13] misc: rp1: RaspberryPi RP1 misc driver

From: Greg Kroah-Hartman
Date: Tue Apr 15 2025 - 11:15:00 EST


On Tue, Apr 15, 2025 at 04:55:05PM +0200, Herve Codina wrote:
> Hi Greg,
>
> On Tue, 15 Apr 2025 16:06:43 +0200
> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Wed, Mar 19, 2025 at 10:52:29PM +0100, Andrea della Porta wrote:
> > > The RaspberryPi RP1 is a PCI multi function device containing
> > > peripherals ranging from Ethernet to USB controller, I2C, SPI
> > > and others.
> >
> > So shouldn't this be using the auxbus code? That's designed to "split
> > up" PCI devices such that you can share them this way.
> >
> > Or did that get rejected somewhere previously?
> >
>
> It doesn't use auxbus probably for the exact same reason that the
> one given for the LAN966x PCI device driver [0] and [1].
>
> Avoid all boiler plate needed with auxbus whereas drivers already exist
> as platform drivers. Internal devices are handled by those platform drivers.
> Those devi just need to be described as platform devices and device-tree is
> fully relevant for that description.
>
> [0] https://lore.kernel.org/all/CAL_Jsq+1r3SSaXupdNAcXO-4rcV-_3_hwh0XJaBsB9fuX5nBCQ@xxxxxxxxxxxxxx/
> [1] https://lore.kernel.org/all/Y9kuxrL3XaCG+blk@xxxxxxxxx/

I really hate creating platform devices below a PCI device, so I'll keep
complaining about this every time people try to do it.

thanks,

greg k-h