[PATCH 2/5] dt-bindings: iommu: arm,smmu-v3: allow clocks

[Arun Iyengar via B4 Relay]

From: Arun Iyengar <aiyengar1990 at gmail.com>

Some SoCs feed the SMMUv3 from a clock that the OS controls. On the
Rockchip RK3588 the MMU-600 for PCIe runs from ACLK_MMU_PCIE, whose only
other consumers are the PCIe controllers. When no PCIe controller is
enabled, the clock framework gates it as unused, and the SMMU can no
longer be accessed.

Allow up to four clocks, so that such a clock can be described and held
by the SMMU driver.

Signed-off-by: Arun Iyengar <aiyengar1990 at gmail.com>
---
 Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml
index c8f22dfdb1db..f8a74730667c 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml
@@ -63,6 +63,13 @@ properties:
 
   msi-parent: true
 
+  clocks:
+    minItems: 1
+    maxItems: 4
+    description:
+      Clocks needed to access the SMMU registers and to keep its translation
+      units running, if they are not managed by firmware.
+
   power-domains:
     maxItems: 1
 

-- 
2.55.0