On Mon, Nov 18, 2024 at 01:01:53PM +0000, Matt Coster wrote: > The current compatible strings are not specific enough to constrain the No, they are specific enough. > hardware in devicetree. For example, the current "img,img-axe" string > refers to the entire family of Series AXE GPUs. The more specific > "img,img-axe-1-16m" string refers to the AXE-1-16M GPU which, unlike the > rest of its family, only uses a single power domain. > > While in this instance there is already "ti,am62-gpu" for the more That's the specific compatible. > specific case, the intent here is to draw a line between properties > inherent to the IP core and choices made by the silicon vendor at > integration time. For example, the number of power domains is a property > of the IP core, whereas the decision to use one or three clocks (see > next patch) is a vendor one. > > Work is currently underway to add support for volcanic-based Imagination > GPUs, for which bindings will be added in "img,powervr-volcanic.yaml". > The split between rogue and volcanic cores is non-obvious at times, so > add a generic top-level "img,img-rogue" compatible string here to allow > for simpler differentiation in devicetrees without referring back to the > bindings. > > Make these changes now before introducing more compatible strings to keep > the legacy versions to a minimum. > > Signed-off-by: Matt Coster <matt.coster@xxxxxxxxxx> > --- > Changes in v2: > - Clarified justification for compatible strings > - Link to v1: https://lore.kernel.org/r/20241105-sets-bxs-4-64-patch-v1-v1-1-4ed30e865892@xxxxxxxxxx > --- > .../devicetree/bindings/gpu/img,powervr-rogue.yaml | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml b/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml > index 256e252f8087fa0d6081f771a01601d34b66fe19..ef7070daf213277d0190fe319e202fdc597337d4 100644 > --- a/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml > +++ b/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml > @@ -12,10 +12,19 @@ maintainers: > > properties: > compatible: > - items: > - - enum: > - - ti,am62-gpu > - - const: img,img-axe # IMG AXE GPU model/revision is fully discoverable > + oneOf: > + - items: > + - enum: > + - ti,am62-gpu > + - const: img,img-axe-1-16m > + - const: img,img-rogue NAK, that's ABI break. You are stuck with whatever you sent earlier. > + > + # This legacy combination of compatible strings was introduced early on before the more > + # specific GPU identifiers were used. Keep it around here for compatibility, but never use > + # "img,img-axe" in new devicetrees. Wrap according to Linux coding style. But anyway this is not needed, just deprecate things. > + - items: > + - const: ti,am62-gpu > + - const: img,img-axe So you want to use deprecated here? Anyway, entire change is not needed and without proper justification. Your marketing terms are not proper justification. Best regards, Krzysztof
