[PATCH v3 1/2] dt-bindings: gpu: img,powervr-rogue: add spacemit,k3-gpu

[Sterling-Ash <liangbaihui@linux.spacemit.com>]

Add a compatible string for the IMG BXM-4-64 GPU integrated into the
SpacemiT K3 SoC. It shares the same core as thead,th1520-gpu but is
kept as a separate compatible entry, since the K3 integration differs
from TH1520 in its clock and power-domain requirements: K3 has a
single "core" clock rather than three, and its GPU power domain is
enabled by the bootloader before Linux boots rather than being
modelled and switched by Linux, so no power-domains property is
required for this platform (unlike the other img,img-bxm-4-64 user).

spacemit,k3-gpu is added to the existing ti,am62-gpu/ti,am62p-gpu/
ti,j721s2-gpu "if" block that restricts clocks to a single entry,
since K3 has the same single-clock requirement. It does not match any
"if" block that constrains power-domains, so that property falls back
to this schema's general constraints, where it is optional. This
leaves room for a power-domains provider to be added later without a
further binding change, should one ever be modelled in Linux for this
SoC.

Signed-off-by: Sterling-Ash <liangbaihui@linux.spacemit.com>
---
v3: also add spacemit,k3-gpu to the existing ti,am62-gpu/ti,am62p-gpu/
    ti,j721s2-gpu "if" block restricting clocks to a single entry --
    previously it fell back to this schema's general clocks constraint
    (1-3 items), which would have let an invalid DT with 2 or 3 clocks
    pass validation (found by automated review on v2).

 .../devicetree/bindings/gpu/img,powervr-rogue.yaml          | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml b/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml
index a1f54dbae3f3..d29f0d163b91 100644
--- a/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml
+++ b/Documentation/devicetree/bindings/gpu/img,powervr-rogue.yaml
@@ -38,6 +38,11 @@ properties:
               - thead,th1520-gpu
           - const: img,img-bxm-4-64
           - const: img,img-rogue
+      - items:
+          - enum:
+              - spacemit,k3-gpu
+          - const: img,img-bxm-4-64
+          - const: img,img-rogue
       - items:
           - enum:
               - ti,am62p-gpu
@@ -100,6 +105,7 @@ allOf:
         compatible:
           contains:
             enum:
+              - spacemit,k3-gpu
               - ti,am62-gpu
               - ti,am62p-gpu
               - ti,j721s2-gpu
-- 
2.34.1