[PATCH v3 2/9] reset: Add Raspberry Pi 4 firmware reset controller

Nicolas Saenz Julienne nsaenzjulienne at suse.de
Mon Jun 29 11:19:57 EDT 2020


On Fri, 2020-06-26 at 12:43 +0200, Philipp Zabel wrote:
> On Wed, 2020-06-17 at 12:44 +0200, Nicolas Saenz Julienne wrote:
> > On Wed, 2020-06-17 at 12:02 +0200, Philipp Zabel wrote:
> > > Hi Nicolas,
> > > 
> > > On Fri, 2020-06-12 at 19:13 +0200, Nicolas Saenz Julienne wrote:
> > > > Raspberry Pi 4's co-processor controls some of the board's HW
> > > > initialization process, but it's up to Linux to trigger it when
> > > > relevant. Introduce a reset controller capable of interfacing with
> > > > RPi4's co-processor that models these firmware initialization routines
> > > > as
> > > > reset lines.
> > > > 
> > > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
> > > > Reviewed-by: Florian Fainelli <f.fainelli at gmail.com>
> > > 
> > > Reviewed-by: Philipp Zabel <p.zabel at pengutronix.de>
> > 
> > Thanks!
> > 
> > > If there is a good reason for the single DT specified reset id, I can
> > > pick up patches 1 and 2.
> > 
> > The idea here is to make sure we're reasonably covered against further
> > changes
> > in firmware. If we define constraints too narrow it can be a pain to support
> > new features without breaking backwards compatibility in dt.
> 
> Ok.
> 
> > > If you change the dts patch 4 to use a number instead of the reset id
> > > define for now, there wouldn't even be a dependency between these reset
> > > and dts patches.
> > 
> > I was under the impression that having an explicit definition was nice to
> > have.
> > What's troubling about creating the dependency?
> 
> Just that the last patch has to wait for the reset patches to be merged
> before it can be applied.

TBH there is no hurry, this only provides a better design on something that's
already available upstream. USB works on RPi4, so I don't mind if this gets
delayed a release.

Regards,
Nicolas

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