Hi Rob,
 
On Friday, April 30, 2021 22:34 -03, Rob Herring [off-list ref] wrote: 
 

On Thu, Apr 22, 2021 at 04:16:00PM +0200, Benjamin Gaignard wrote:

quoted

Add compatible for the second version of IOMMU hardware block.
RK356x IOMMU can also be link to a power domain.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
version 2:
 - Add power-domains property

 .../devicetree/bindings/iommu/rockchip,iommu.yaml          | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml
index 0db208cf724a..e54353ccd1ec 100644
--- a/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml
+++ b/Documentation/devicetree/bindings/iommu/rockchip,iommu.yaml

@@ -19,7 +19,9 @@ description: |+
 
 properties:
   compatible:
-    const: rockchip,iommu
+    enum:
+      - rockchip,iommu
+      - rockchip,iommu-v2

This should be SoC specific.

It seems iommu-v2 is really the name Rockchip gives to this IOMMU IP core.
Can we keep the "rockchip,iommu-v2" compatible, and add SoC-specific ones, as we normally do:

compatible = "rockchip,rk3568-iommu", "rockchip,iommu-v2";

Just like we'd do with any peripheral:

compatible = "st,stm32-dwmac", "snps,dwmac-3.50a";

Thanks!
Ezequiel