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@xxxxxxxxxxxxx> >> --- >> .../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 -- Lars Povlsen, Microchip
