[PATCH 3/5] dt-bindings: reset: ocelot: Add documentation for 'microchip,reset-switch-core' property

[Sebastian Reichel]

Hi,

On Tue, Jun 02, 2020 at 11:49:08AM +0200, Lars Povlsen wrote:
> Rob Herring writes:
> > On Wed, May 13, 2020 at 03:08:40PM +0200, Lars Povlsen wrote:
> >> This documents the 'microchip,reset-switch-core' property in the
> >> ocelot-reset driver.
> >>
> >> Signed-off-by: Lars Povlsen <lars.povlsen at microchip.com>
> >> ---
> >>  .../devicetree/bindings/power/reset/ocelot-reset.txt        | 6 ++++++
> >>  1 file changed, 6 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
> >> index 4d530d8154848..20fff03753ad2 100644
> >> --- a/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
> >> +++ b/Documentation/devicetree/bindings/power/reset/ocelot-reset.txt
> >> @@ -9,9 +9,15 @@ microchip Sparx5 armv8 SoC's.
> >>  Required Properties:
> >>   - compatible: "mscc,ocelot-chip-reset" or "microchip,sparx5-chip-reset"
> >>
> >> +Optional properties:
> >> +- microchip,reset-switch-core : Perform a switch core reset at the
> >> +  time of driver load. This is may be used to initialize the switch
> >> +  core to a known state (before other drivers are loaded).
> >
> > How do you know when other drivers are loaded? This could be a module
> > perhaps. Doesn't seem like something that belongs in DT.
> >
> 
> The reset driver is loaded at postcore_initcall() time, which ensures it
> is loaded before other drivers using the switch core. I noticed other
> drivers do the same to do low-level system reset and initialization at
> early boot time.
> 
> > Can this behavior be implied with "microchip,sparx5-chip-reset"?
> 
> Since we need to cater for both modus operandi, I would need two driver
> compatible strings per platform, which scales worse than a single
> property.
> 
> The "microchip,reset-switch-core" is a device configuration property
> which tells the system (driver) how the hw should be handled. Since you
> do not *always* want to reset the switch core (f.ex. when implementing
> systems with warm reboot), I think it makes perfect sense - but I may be
> biased off course :-)
> 
> Thank you for (all) of your comments, by the way!
> 
> ---Lars
> > Rob

Is this series still needed? Did I miss a follow-up?

-- Sebastian
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