[PATCH 01/11] dt-bindings: iommu: arm,smmu-v3: make PRI IRQ optional

[Andre Przywara]

The Page Request Interface (PRI) is an optional PCIe feature. As such, a
SMMU would not need to handle it if the PCIe host bridge or the SMMU
itself do not implement it. Also an SMMU could be connected to a platform
device, without any PRI functionality whatsoever.
In all cases there would be no SMMU PRI queue interrupt to be wired up
to an interrupt controller.

Relax the binding to allow specifying three interrupts, omitting the PRI
IRQ. At the moment, with the "eventq,gerror,priq,cmdq-sync" order, we
would need to sacrifice the command queue sync interrupt as well, which
might not be desired.
The Linux driver does not care about any order at all, just picks IRQs
based on their names, and treats all (wired) IRQs as optional.

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
 .../bindings/iommu/arm,smmu-v3.yaml           | 21 ++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml
index e87bfbcc69135..6b3111f1f06ce 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml
@@ -37,12 +37,23 @@ properties:
           hardware supports just a single, combined interrupt line.
           If provided, then the combined interrupt will be used in preference to
           any others.
-      - minItems: 2
+      - minItems: 1
         items:
-          - const: eventq     # Event Queue not empty
-          - const: gerror     # Global Error activated
-          - const: priq       # PRI Queue not empty
-          - const: cmdq-sync  # CMD_SYNC complete
+          - enum:
+              - eventq     # Event Queue not empty
+              - gerror     # Global Error activated
+              - cmdq-sync  # CMD_SYNC complete
+              - priq       # PRI Queue not empty
+          - enum:
+              - gerror
+              - cmdq-sync
+              - priq
+          - enum:
+              - cmdq-sync
+              - priq
+          - enum:
+              - cmdq-sync
+              - priq
 
   '#iommu-cells':
     const: 1
-- 
2.25.1