[PATCH v2 1/2] dt-bindings: firmware: arm,scmi: Support notification completion channel

["Peng Fan (OSS)" <peng.fan@oss.nxp.com>]

From: Peng Fan <peng.fan@nxp.com>

Per System Control Management Interface specification:
" Completion interrupts:This transport supports polling or interrupt driven
  modes of communication. In interrupt mode, when the callee completes
  processing a message, it raises an interrupt to the caller. Hardware
  support for completion interrupts is optional."
So add an optional mailbox channel for notification completion interrupts.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 Documentation/devicetree/bindings/firmware/arm,scmi.yaml | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
index 7de2c29606e5..308af58180d1 100644
--- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
+++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
@@ -72,14 +72,17 @@ properties:
           - const: tx
           - const: tx_reply
           - const: rx
+          - const: rx_reply
         minItems: 2
 
   mboxes:
     description:
       List of phandle and mailbox channel specifiers. It should contain
-      exactly one, two or three mailboxes; the first one or two for transmitting
-      messages ("tx") and another optional ("rx") for receiving notifications
-      and delayed responses, if supported by the platform.
+      exactly one, two, three or four mailboxes; the first one or two for
+      transmitting messages ("tx") and another optional ("rx") for receiving
+      notifications and delayed responses, if supported by the platform.
+      The optional ("rx_reply") is for notifications completion interrupt,
+      if supported by the platform.
       The number of mailboxes needed for transmitting messages depends on the
       type of channels exposed by the specific underlying mailbox controller;
       one single channel descriptor is enough if such channel is bidirectional,
@@ -92,9 +95,10 @@ properties:
        2 mbox / 2 shmem => SCMI TX and RX over 2 mailbox bidirectional channels
        2 mbox / 1 shmem => SCMI TX over 2 mailbox unidirectional channels
        3 mbox / 2 shmem => SCMI TX and RX over 3 mailbox unidirectional channels
+       4 mbox / 2 shmem => SCMI TX and RX over 4 mailbox unidirectional channels
       Any other combination of mboxes and shmem is invalid.
     minItems: 1
-    maxItems: 3
+    maxItems: 4
 
   shmem:
     description:

-- 
2.37.1