[PATCH v3 2/9] dt-bindings: dma: nvidia,tegra186-gpc-dma: Make reset optional

[Akhil R]

On Tegra264, GPCDMA reset control is not exposed to Linux and is handled
by the boot firmware.

Although the reset was not exposed in Tegra234 as well, the firmware
supported a dummy reset which just returns success on reset without doing
an actual reset. This is also not supported in Tegra264. Therefore mark
'reset' and 'reset-names' properties as required only for devices prior
to Tegra264.

This also necessitates that the Tegra264 compatible be standalone and
cannot have the fallback compatible of Tegra186. Since there is no
functional impact, we keep reset as required for Tegra234 to avoid
breaking the ABI.

Signed-off-by: Akhil R <akhilrajeev@xxxxxxxxxx>
---
 .../bindings/dma/nvidia,tegra186-gpc-dma.yaml | 25 +++++++++++++------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml b/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml
index b5d8fd0b281d..b849d4cc2901 100644
--- a/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml
+++ b/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml
@@ -16,16 +16,14 @@ maintainers:
   - Rajesh Gumasta <rgumasta@xxxxxxxxxx>
   - Akhil R <akhilrajeev@xxxxxxxxxx>
 
-allOf:
-  - $ref: dma-controller.yaml#
-
 properties:
   compatible:
     oneOf:
-      - const: nvidia,tegra186-gpcdma
+      - enum:
+          - nvidia,tegra264-gpcdma
+          - nvidia,tegra186-gpcdma
       - items:
           - enum:
-              - nvidia,tegra264-gpcdma
               - nvidia,tegra234-gpcdma
               - nvidia,tegra194-gpcdma
           - const: nvidia,tegra186-gpcdma
@@ -69,12 +67,25 @@ required:
   - compatible
   - reg
   - interrupts
-  - resets
-  - reset-names
   - "#dma-cells"
   - iommus
   - dma-channel-mask
 
+allOf:
+  - $ref: dma-controller.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - nvidia,tegra186-gpcdma
+              - nvidia,tegra194-gpcdma
+              - nvidia,tegra234-gpcdma
+    then:
+      required:
+        - resets
+        - reset-names
+
 additionalProperties: false
 
 examples:
-- 
2.50.1