On Fri, Oct 6, 2017 at 6:01 AM, Jassi Brar [off-list ref] wrote:

On Fri, Oct 6, 2017 at 4:50 AM, Rob Herring [off-list ref] wrote:

quoted

On Thu, Sep 28, 2017 at 02:11:27PM +0100, Sudeep Holla wrote:

quoted

This patch adds ARM MHU specific mailbox client bindings to support
SCMI. Since SCMI specification just requires doorbell mechanism from
mailbox controllers, we add mailbox data to specify the doorbell bit(s).

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sudeep Holla <redacted>
---
 .../devicetree/bindings/arm/arm,mhu-scmi.txt          | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/arm,mhu-scmi.txt

diff --git a/Documentation/devicetree/bindings/arm/arm,mhu-scmi.txt b/Documentation/devicetree/bindings/arm/arm,mhu-scmi.txt
new file mode 100644
index 000000000000..8c106f1cdeb8
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/arm,mhu-scmi.txt

@@ -0,0 +1,19 @@
+ARM MHU mailbox client bindings for SCMI Message Protocol
+----------------------------------------------------------
+
+This binding is intended to define the ARM MHU specific extensions to
+the generic SCMI bindings[2].
+
+Required properties:
+
+The scmi node with the following properties shall be under the /firmware/ node.
+
+- compatible : shall be "arm,scmi" and "arm,mhu-scmi"

Most specific first.

quoted

+- mbox-data : For each phandle listed in mboxes property, an unsigned 32-bit
+           data as expected by the mailbox controller

Shouldn't that be cells as part of mboxes property?

A MHU client can send any number of commands (such u32 values) over a channel.
This client (SCMI) sends just one command over a channel, but other
clients may/do send two or more.

Okay, then I guess I don't understand why this is in DT.

Rob