Re: [PATCH 08/11] misc: rp1: RaspberryPi RP1 misc driver

Andrea della Porta
2024-09-03T14:57:52Z

Hi Andrew,

On 16:21 Fri 30 Aug , Andrew Lunn wrote:
> On Fri, Aug 30, 2024 at 03:49:04PM +0200, Andrea della Porta wrote:
> > Hi Krzysztof,
> >
> > On 10:38 Wed 21 Aug , Krzysztof Kozlowski wrote:
> > > On Tue, Aug 20, 2024 at 04:36:10PM +0200, Andrea della Porta wrote:
> > > > The RaspberryPi RP1 is ia PCI multi function device containing
> > > > peripherals ranging from Ethernet to USB controller, I2C, SPI
> > > > and others.
> > > > Implement a bare minimum driver to operate the RP1, leveraging
> > > > actual OF based driver implementations for the on-borad peripherals
> > > > by loading a devicetree overlay during driver probe.
> > > > The peripherals are accessed by mapping MMIO registers starting
> > > > from PCI BAR1 region.
> > > > As a minimum driver, the peripherals will not be added to the
> > > > dtbo here, but in following patches.
> > > >
> > > > Link: https://datasheets.raspberrypi.com/rp1/rp1-peripherals.pdf
> > > > Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
> > > > ---
> > > > MAINTAINERS | 2 +
> > > > arch/arm64/boot/dts/broadcom/rp1.dtso | 152 ++++++++++++
> > >
> > > Do not mix DTS with drivers.
> > >
> > > These MUST be separate.
> >
> > Separating the dtso from the driver in two different patches would mean
> > that the dtso patch would be ordered before the driver one. This is because
> > the driver embeds the dtbo binary blob inside itself, at build time. So
> > in order to build the driver, the dtso needs to be there also. This is not
> > the standard approach used with 'normal' dtb/dtbo, where the dtb patch is
> > ordered last wrt the driver it refers to.
> > Are you sure you want to proceed in this way?
>
> It is more about they are logically separate things. The .dtb/dtbo
> describes the hardware. It should be possible to review that as a
> standalone thing. The code them implements the binding. It makes no
> sense to review the code until the binding is correct, because changes
> to the binding will need changes to the code. Hence, we want the
> binding first, then the code which implements it.

Ack.

Cheers,
Andrea

>
> Andrew