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From:   Konrad Dybcio <konrad.dybcio@linaro.org>
Date:   Mon, 29 May 2023 15:52:21 +0200
Subject: [PATCH v8 02/18] dt-bindings: display/msm/gmu: Add GMU wrapper
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References: <20230223-topic-gmuwrapper-v8-0-69c68206609e@linaro.org>
In-Reply-To: <20230223-topic-gmuwrapper-v8-0-69c68206609e@linaro.org>
To:     Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Akhil P Oommen <quic_akhilpo@quicinc.com>,
        Conor Dooley <conor+dt@kernel.org>
Cc:     linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
        freedreno@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Rob Clark <robdclark@chromium.org>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Precedence: bulk

The "GMU Wrapper" is Qualcomm's name for "let's treat the GPU blocks
we'd normally assign to the GMU as if they were a part of the GMU, even
though they are not". It's a (good) software representation of the GMU_CX
and GMU_GX register spaces within the GPUSS that helps us programatically
treat these de-facto GMU-less parts in a way that's very similar to their
GMU-equipped cousins, massively saving up on code duplication.

The "wrapper" register space was specifically designed to mimic the layout
of a real GMU, though it rather obviously does not have the M3 core et al.

To sum it all up, the GMU wrapper is essentially a register space within
the GPU, which Linux sees as a dumbed-down regular GMU: there's no clocks,
interrupts, multiple reg spaces, iommus and OPP. Document it.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 .../devicetree/bindings/display/msm/gmu.yaml       | 50 ++++++++++++++++------
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/msm/gmu.yaml b/Documentation/devicetree/bindings/display/msm/gmu.yaml
index f31a26305ca9..5fc4106110ad 100644
--- a/Documentation/devicetree/bindings/display/msm/gmu.yaml
+++ b/Documentation/devicetree/bindings/display/msm/gmu.yaml
@@ -19,16 +19,18 @@ description: |
 
 properties:
   compatible:
-    items:
-      - pattern: '^qcom,adreno-gmu-6[0-9][0-9]\.[0-9]$'
-      - const: qcom,adreno-gmu
+    oneOf:
+      - items:
+          - pattern: '^qcom,adreno-gmu-6[0-9][0-9]\.[0-9]$'
+          - const: qcom,adreno-gmu
+      - const: qcom,adreno-gmu-wrapper
 
   reg:
-    minItems: 3
+    minItems: 1
     maxItems: 4
 
   reg-names:
-    minItems: 3
+    minItems: 1
     maxItems: 4
 
   clocks:
@@ -44,7 +46,6 @@ properties:
       - description: GMU HFI interrupt
       - description: GMU interrupt
 
-
   interrupt-names:
     items:
       - const: hfi
@@ -72,14 +73,8 @@ required:
   - compatible
   - reg
   - reg-names
-  - clocks
-  - clock-names
-  - interrupts
-  - interrupt-names
   - power-domains
   - power-domain-names
-  - iommus
-  - operating-points-v2
 
 additionalProperties: false
 
@@ -218,6 +213,28 @@ allOf:
             - const: axi
             - const: memnoc
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: qcom,adreno-gmu-wrapper
+    then:
+      properties:
+        reg:
+          items:
+            - description: GMU wrapper register space
+        reg-names:
+          items:
+            - const: gmu
+    else:
+      required:
+        - clocks
+        - clock-names
+        - interrupts
+        - interrupt-names
+        - iommus
+        - operating-points-v2
+
 examples:
   - |
     #include <dt-bindings/clock/qcom,gpucc-sdm845.h>
@@ -250,3 +267,12 @@ examples:
         iommus = <&adreno_smmu 5>;
         operating-points-v2 = <&gmu_opp_table>;
     };
+
+    gmu_wrapper: gmu@596a000 {
+        compatible = "qcom,adreno-gmu-wrapper";
+        reg = <0x0596a000 0x30000>;
+        reg-names = "gmu";
+        power-domains = <&gpucc GPU_CX_GDSC>,
+                        <&gpucc GPU_GX_GDSC>;
+        power-domain-names = "cx", "gx";
+    };

-- 
2.40.1