[PATCH v6 01/10] dt-bindings: dma: nvidia,tegra186-gpc-dma: Make reset optional

Akhil R
2026-03-31T10:23:49Z

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

Although 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 BPMP. 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.

Fixes: bb8c97571db5 ("dt-bindings: dma: Add Tegra264 compatible string")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
---
.../bindings/dma/nvidia,tegra186-gpc-dma.yaml | 23 +++++++++++++------
1 file changed, 16 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 0dabe9bbb219..64f1e9d9896d 100644
--- a/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml
+++ b/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml
@@ -15,16 +15,14 @@ maintainers:
- Jon Hunter <jonathanh@nvidia.com>
- Rajesh Gumasta <rgumasta@nvidia.com>

-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
@@ -60,12 +58,23 @@ 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
+ then:
+ required:
+ - resets
+ - reset-names
+
additionalProperties: false

examples:
--
2.50.1