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From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>
Cc:     linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] dt-bindings: soc: smem: Make indirection optional
Date:   Mon, 27 Sep 2021 21:45:44 -0700
Message-Id: <20210928044546.4111223-1-bjorn.andersson@linaro.org>
MIME-Version: 1.0
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In the olden days the Qualcomm shared memory (SMEM) region consisted of
multiple chunks of memory, so SMEM was described as a standalone node
with references to its various memory regions.

But practically all modern Qualcomm platforms has a single reserved memory
region used for SMEM. So rather than having to use two nodes to describe
the one SMEM region, update the binding to allow the reserved-memory
region alone to describe SMEM.

The olden format is preserved as valid, as this is widely used already.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 .../bindings/soc/qcom/qcom,smem.yaml          | 34 ++++++++++++++++---
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smem.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smem.yaml
index f7e17713b3d8..4149cf2b66be 100644
--- a/Documentation/devicetree/bindings/soc/qcom/qcom,smem.yaml
+++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smem.yaml
@@ -10,14 +10,18 @@ maintainers:
   - Andy Gross <agross@kernel.org>
   - Bjorn Andersson <bjorn.andersson@linaro.org>
 
-description: |
-  This binding describes the Qualcomm Shared Memory Manager, used to share data
-  between various subsystems and OSes in Qualcomm platforms.
+description:
+  This binding describes the Qualcomm Shared Memory Manager, a region of
+  reserved-memory used to share data between various subsystems and OSes in
+  Qualcomm platforms.
 
 properties:
   compatible:
     const: qcom,smem
 
+  reg:
+    maxItems: 1
+
   memory-region:
     maxItems: 1
     description: handle to memory reservation for main SMEM memory region.
@@ -29,11 +33,19 @@ properties:
     $ref: /schemas/types.yaml#/definitions/phandle
     description: handle to RPM message memory resource
 
+  no-map: true
+
 required:
   - compatible
-  - memory-region
   - hwlocks
 
+oneOf:
+  - required:
+      - reg
+      - no-map
+  - required:
+      - memory-region
+
 additionalProperties: false
 
 examples:
@@ -43,6 +55,20 @@ examples:
         #size-cells = <1>;
         ranges;
 
+        smem@fa00000 {
+            compatible = "qcom,smem";
+            reg = <0xfa00000 0x200000>;
+            no-map;
+
+            hwlocks = <&tcsr_mutex 3>;
+        };
+    };
+  - |
+    reserved-memory {
+        #address-cells = <1>;
+        #size-cells = <1>;
+        ranges;
+
         smem_region: smem@fa00000 {
             reg = <0xfa00000 0x200000>;
             no-map;
-- 
2.29.2