Re: [PATCH 1/2] dt-bindings: arm: arm,scmi: add smc/hvc transports

From: Marc Zyngier
Date: Fri Feb 07 2020 - 05:08:41 EST


On 2020-02-06 13:01, peng.fan@xxxxxxx wrote:
From: Peng Fan <peng.fan@xxxxxxx>

SCMI could use SMC/HVC as tranports, so add into devicetree
binding doc.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---
Documentation/devicetree/bindings/arm/arm,scmi.txt | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/arm,scmi.txt
b/Documentation/devicetree/bindings/arm/arm,scmi.txt
index f493d69e6194..03cff8b55a93 100644
--- a/Documentation/devicetree/bindings/arm/arm,scmi.txt
+++ b/Documentation/devicetree/bindings/arm/arm,scmi.txt
@@ -14,7 +14,7 @@ Required properties:

The scmi node with the following properties shall be under the /firmware/ node.

-- compatible : shall be "arm,scmi"
+- compatible : shall be "arm,scmi" or "arm,scmi-smc"
- mboxes: List of phandle and mailbox channel specifiers. It should contain
exactly one or two mailboxes, one for transmitting messages("tx")
and another optional for receiving the notifications("rx") if
@@ -25,6 +25,8 @@ The scmi node with the following properties shall be
under the /firmware/ node.
protocol identifier for a given sub-node.
- #size-cells : should be '0' as 'reg' property doesn't have any size
associated with it.
+- arm,smc-id : SMC id required when using smc transports
+- arm,hvc-id : HVC id required when using hvc transports

Optional properties:

Not directly related to DT: Why do we need to distinguish between SMC and HVC?
Other SMC/HVC capable protocols are able to pick the right one based on the PSCI
conduit.

This is how the Spectre mitigations work already. Why is that any different?

Thanks,

M.
--
Jazz is not dead. It just smells funny...