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From:   Nikunj Kela <quic_nkela@quicinc.com>
To:     <sudeep.holla@arm.com>
CC:     <cristian.marussi@arm.com>, <robh+dt@kernel.org>,
        <krzysztof.kozlowski+dt@linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <lkp@intel.com>, Nikunj Kela <quic_nkela@quicinc.com>
Subject: [PATCH v2 1/2] dt-bindings: firmware: arm,scmi: support parameter passing in smc/hvc
Date:   Mon, 10 Apr 2023 11:20:57 -0700
Message-ID: <20230410182058.8949-2-quic_nkela@quicinc.com>
In-Reply-To: <20230410182058.8949-1-quic_nkela@quicinc.com>
References: <20230409181918.29270-1-quic_nkela@quicinc.com>
 <20230410182058.8949-1-quic_nkela@quicinc.com>
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Currently, smc/hvc calls are made with smc-id only. The parameters are
all set to zeros. This patch defines two optional device tree bindings,
that can be used to pass parameters in smc/hvc calls.

This is useful when multiple scmi instances are used with common smc-id.

Signed-off-by: Nikunj Kela <quic_nkela@quicinc.com>
---
 .../devicetree/bindings/firmware/arm,scmi.yaml | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
index 5824c43e9893..ecf76b763c8c 100644
--- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
+++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
@@ -115,6 +115,23 @@ properties:
     description:
       SMC id required when using smc or hvc transports
 
+  arm,smc32-params:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description:
+      An optional parameter list passed in smc32 or hvc32 calls
+    default: 0
+    minItems: 1
+    maxItems: 6
+
+  arm,smc64-params:
+    $ref: /schemas/types.yaml#/definitions/uint64-array
+    description:
+      An optional parameter list passed in smc64 or hvc64 calls.
+      This is valid only on ARM64 machines.
+    default: 0
+    minItems: 1
+    maxItems: 6
+
   linaro,optee-channel-id:
     $ref: /schemas/types.yaml#/definitions/uint32
     description:
@@ -427,6 +444,7 @@ examples:
             compatible = "arm,scmi-smc";
             shmem = <&cpu_scp_lpri0>, <&cpu_scp_lpri1>;
             arm,smc-id = <0xc3000001>;
+            arm,smc64-params = <0xcd974d6c 0x5ed97289>;
 
             #address-cells = <1>;
             #size-cells = <0>;
-- 
2.17.1