[RFC PATCH 1/2] dt-bindings: i2c: renesas,rcar-i2c: document SMBusAlert usage

[Wolfram Sang <wsa+renesas@sang-engineering.com>]

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Question: Should I remove 'smbus_alert' from the enum of
'interrupt-names'? It is already documented here:

https://github.com/devicetree-org/dt-schema/commit/c51125d571cac9596048e888a856d70650e400e0


 .../bindings/i2c/renesas,rcar-i2c.yaml         | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml b/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
index 6cc60c3f61cd..2eed3ae7c57d 100644
--- a/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
@@ -60,7 +60,20 @@ properties:
     maxItems: 1
 
   interrupts:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
+    description:
+      Without interrupt-names, the first interrupt listed must be the one
+      of the IP core, the second optional interrupt listed must handle
+      SMBALERT#, likely a GPIO.
+
+  interrupt-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      enum:
+        - main
+        - smbus_alert
 
   clock-frequency:
     description:
@@ -155,7 +168,8 @@ examples:
     i2c0: i2c@e6508000 {
         compatible = "renesas,i2c-r8a7791", "renesas,rcar-gen2-i2c";
         reg = <0xe6508000 0x40>;
-        interrupts = <GIC_SPI 287 IRQ_TYPE_LEVEL_HIGH>;
+        interrupts-extended = <&gic GIC_SPI 287 IRQ_TYPE_LEVEL_HIGH>, <&gpio5 1 IRQ_TYPE_EDGE_FALLING>;
+        interrupt-names = "main", "smbus_alert";
         clock-frequency = <400000>;
         clocks = <&cpg CPG_MOD 931>;
         power-domains = <&sysc R8A7791_PD_ALWAYS_ON>;
-- 
2.43.0