Le mercredi 18 juin 2025 à 16:55 +0100, Conor Dooley a écrit :

On Wed, Jun 18, 2025 at 04:09:11PM +0200, Benjamin Gaignard wrote:

quoted

Add a device tree binding for the Verisilicon (VSI) IOMMU.
This IOMMU sits in front of hardware encoder and decoder
blocks on SoCs using Verisilicon IP, such as the Rockchip RK3588.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
changes in version 2:
- Add a compatible "rockchip,rk3588-av1-iommu"
- Fix clock-names in binding 
- Remove "vsi_mmu" label in binding example.

 .../bindings/iommu/verisilicon,iommu.yaml     | 72 +++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml

diff --git a/Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml

b/Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml
new file mode 100644
index 000000000000..9ae4a45d76f4

--- /dev/null
+++ b/Documentation/devicetree/bindings/iommu/verisilicon,iommu.yaml

@@ -0,0 +1,72 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iommu/verisilicon,iommu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Verisilicon IOMMU
+
+maintainers:
+  - Benjamin Gaignard <benjamin.gaignard@collabora.com>
+
+description: |+
+  A Versilicon iommu translates io virtual addresses to physical addresses for
+  its associated video decoder.
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - verisilicon,iommu
+          - rockchip,rk3588-av1-iommu

This isn't right. Firstly, the "oneOf: - enum" construct doesn't do
anything. oneOf one item is just the item. Secondly this still allows
verisilicon,iommu in isolation which is not okay. What you actually want
here is
items:
  - const: a
  - const: b

Thirdly, Nicolas mentioned that the version of this iommu is 1.2.0,
which I would like to see reflected in the compatible.

I believe just 1.2 will be sufficient, the last number is the build number,
the IP is interface is unchanged.

Nicolas