Hi Rob, On Mon, Mar 20, 2023 at 3:49 PM Rob Herring <robh@xxxxxxxxxx> wrote: > On Mon, Mar 13, 2023 at 09:40:26PM +0900, Yoshihiro Shimoda wrote: > > Since R-Car Gen4 does not have the main IPMMU IMSSTR register, update > > the bindings to drop the interrupt bit number from the > > renesas,ipmmu-main property. > > Wouldn't it be easier to define a value meaning 'no interrupt bit' such > as 0 or ~0 than having a variable sized property to parse? (That would be ~0, as 0 is a valid bit number) In theory: yes. In practice: it doesn't matter much, as the driver doesn't use the value anyway. Cfr. its parsing code being reworked in your patch "[PATCH] iommu: Use of_property_present() for testing DT property presence" https://lore.kernel.org/all/20230310144709.1542910-1-robh@xxxxxxxxxx So yes, using ~0 would simplify the bindings, but would complicate the DTS files (and probably we should introduce a #define instead of using ~0 or 0xffffffff or some other value). > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> > > [geert: Re-add removed items level, add minItems/maxItems constraints] > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > > --- > > Changes from v3: > > https://lore.kernel.org/all/20230209133440.2643228-1-yoshihiro.shimoda.uh@xxxxxxxxxxx/ > > - Revise the dt-bindings by Geert-san (Thanks a lot!). > > > > .../bindings/iommu/renesas,ipmmu-vmsa.yaml | 32 ++++++++++++++----- > > 1 file changed, 24 insertions(+), 8 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.yaml b/Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.yaml > > index 72308a4c14e7..be90f68c11d1 100644 > > --- a/Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.yaml > > +++ b/Documentation/devicetree/bindings/iommu/renesas,ipmmu-vmsa.yaml > > @@ -74,16 +74,16 @@ properties: > > renesas,ipmmu-main: > > $ref: /schemas/types.yaml#/definitions/phandle-array > > items: > > - - items: > > + - minItems: 1 > > + items: > > - description: phandle to main IPMMU > > - - description: the interrupt bit number associated with the particular > > - cache IPMMU device. The interrupt bit number needs to match the main > > - IPMMU IMSSTR register. Only used by cache IPMMU instances. > > + - description: > > + The interrupt bit number associated with the particular cache > > + IPMMU device. If present, the interrupt bit number needs to match > > + the main IPMMU IMSSTR register. Only used by cache IPMMU > > + instances. > > description: > > - Reference to the main IPMMU phandle plus 1 cell. The cell is > > - the interrupt bit number associated with the particular cache IPMMU > > - device. The interrupt bit number needs to match the main IPMMU IMSSTR > > - register. Only used by cache IPMMU instances. > > + Reference to the main IPMMU. > > > > required: > > - compatible > > @@ -109,6 +109,22 @@ allOf: > > required: > > - power-domains > > > > + - if: > > + properties: > > + compatible: > > + contains: > > + const: renesas,rcar-gen4-ipmmu-vmsa > > + then: > > + properties: > > + renesas,ipmmu-main: > > + items: > > + - maxItems: 1 > > + else: > > + properties: > > + renesas,ipmmu-main: > > + items: > > + - minItems: 2 > > + Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
