On Sun, Jul 03, 2022 at 01:04:20AM +0200, Martin Blumenstingl wrote: > Hi Rob, > > On Fri, Jul 1, 2022 at 6:33 PM Rob Herring <robh@xxxxxxxxxx> wrote: > > > > On Tue, Jun 28, 2022 at 02:44:35PM +0200, Martin Blumenstingl wrote: > > > The Lantiq Amazon-SE, Danube, xRX100 and xRX200 SoCs have up to two USB2 > > > PHYs which are part of the RCU register space. The RCU registers on > > > these SoCs are using big endian. Update the binding for these SoCs to > > > properly describe this IP: > > > - Add compatible strings for Amazon-SE, Danube and xRX100 > > > - Rename the xRX200 compatible string (which is not used anywhere) and > > > switch to the one previously documented in mips/lantiq/rcu.txt > > > - Allow usage of "simple-mfd" and "syscon" in the compatible string so the > > > child devices (USB2 PHYs) can be described > > > - Allow #address-cells and #size-cells to be set to 1 for describing the > > > child devices (USB2 PHYs) > > > - #reset-cells must always be 3 (offset, reset bit and status bit) on the > > > legacy SoCs while LGM uses a fixed value of 2 (offset and reset bit - > > > status bit is always identical to the reset bit). > > > > > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> > > > --- > > > .../bindings/reset/intel,rcu-gw.yaml | 84 +++++++++++++++++-- > > > 1 file changed, 79 insertions(+), 5 deletions(-) > > > > > > diff --git a/Documentation/devicetree/bindings/reset/intel,rcu-gw.yaml b/Documentation/devicetree/bindings/reset/intel,rcu-gw.yaml > > > index be64f8597710..b90913c7b7d3 100644 > > > --- a/Documentation/devicetree/bindings/reset/intel,rcu-gw.yaml > > > +++ b/Documentation/devicetree/bindings/reset/intel,rcu-gw.yaml > > > @@ -11,9 +11,16 @@ maintainers: > > > > > > properties: > > > compatible: > > > - enum: > > > - - intel,rcu-lgm > > > - - intel,rcu-xrx200 > > > > It is okay to remove/change this because ? > I'll update the description in v2. The "intel,rcu-xrx200" compatible > string isn't used anywhere (upstream or downstream in OpenWrt). > u-boot on Lantiq xRX200 SoCs is too old to pass a dtb to the kernel, > so we're appending the DTB to the kernel image. > > > > + oneOf: > > > + - items: > > > + - enum: > > > + - lantiq,ase-rcu > > > + - lantiq,danube-rcu > > > + - lantiq,xrx100-rcu > > > + - lantiq,xrx200-rcu > > > + - const: simple-mfd > > > > This says child nodes have 0 dependence on anything in the parent node. > > Such as a clock in the parent needing to be enabled. > > > > > + - const: syscon > > > > Given the child nodes depend on this, I find the combination to be a > > contradiction. But it's widely used, so oh well. > I can think of two ways to solve this: > 1) remove the simple-mfd compatible string and make the driver also > discover child nodes > 2) remove the simple-mfd compatible string and remove the USB PHY > child nodes - then add add #phy-cells = <1> to the RCU node itself > (and somehow update the RCU and USB PHY drivers accordingly) > 3) introduce a separate child node for the reset-controller, then the > child nodes depend on each other (but there's no strict dependency on > the parent anymore other than the fact that the parent needs a > "syscon" compatible string). > > My understanding of this IP block is that it was initially designed as > a reset controller, hence its name "reset controller unit" (RCU). Then > additional logic was added after the fact. > So I think 1) (dropping the simple-mfd compatible string) or 2) > (dropping the simple-mfd compatible string and the child nodes > altogether) is the right way to go here. Which route would you go and > why? 2 would be my choice. That's the simplest binding. Unless the phy registers show up in different places on multiple devices, then maybe it's worth keeping the child node. Rob
