Re: [PATCH v6 1/2] dt-bindings: drm/msm/a6xx: Document GMU and update GPU bindings

[Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

On Wed, Dec 12, 2018 at 02:18:47PM -0700, Jordan Crouse wrote:
> Update the GPU bindings and document the new bindings for the GMU
> device found with Adreno a6xx targets.
> 
> Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
> ---
>  .../devicetree/bindings/display/msm/gmu.txt   | 56 +++++++++++++++++++
>  .../devicetree/bindings/display/msm/gpu.txt   | 41 +++++++++++++-
>  2 files changed, 94 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/display/msm/gmu.txt
> 
> diff --git a/Documentation/devicetree/bindings/display/msm/gmu.txt b/Documentation/devicetree/bindings/display/msm/gmu.txt
> new file mode 100644
> index 000000000000..6152cb551d29
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/msm/gmu.txt
> @@ -0,0 +1,56 @@
> +Qualcomm adreno/snapdragon GMU (Graphics management unit)
> +
> +The GMU is a programmable power controller for the GPU. the CPU controls the
> +GMU which in turn handles power controls for the GPU.
> +
> +Required properties:
> +- compatible:
> +  * "qcom,adreno-gmu"

I probably asked before, but this needs a specific compatible unless you 
have reliable version/capability registers. If you do, please state that 
here.

> +- reg: Physical base address and length of the GMU registers.
> +- reg-names: Matching names for the register regions
> +  * "gmu"
> +  * "gmu_pdc"
> +  * "gmu_pdc_seg"
> +- interrupts: The interrupt signals from the GMU.
> +- interrupt-names: Matching names for the interrupts
> +  * "hfi"
> +  * "gmu"
> +- clocks: phandles to the device clocks
> +- clock-names: Matching names for the clocks
> +   * "gmu"
> +   * "cxo"
> +   * "axi"
> +   * "mnoc"
> +- power-domains: should be <&clock_gpucc GPU_CX_GDSC>
> +- iommus: phandle to the adreno iommu
> +- operating-points-v2: phandle to the OPP operating points
> +
> +Example:
> +
> +/ {
> +	...
> +
> +	gmu: gmu@506a000 {
> +		compatible="qcom,adreno-gmu";
> +
> +		reg = <0x506a000 0x30000>,
> +			<0xb280000 0x10000>,
> +			<0xb480000 0x10000>;
> +		reg-names = "gmu", "gmu_pdc", "gmu_pdc_seq";
> +
> +		interrupts = <GIC_SPI 304 IRQ_TYPE_LEVEL_HIGH>,
> +		     <GIC_SPI 305 IRQ_TYPE_LEVEL_HIGH>;
> +		interrupt-names = "hfi", "gmu";
> +
> +		clocks = <&gpucc GPU_CC_CX_GMU_CLK>,
> +			<&gpucc GPU_CC_CXO_CLK>,
> +			<&gcc GCC_DDRSS_GPU_AXI_CLK>,
> +			<&gcc GCC_GPU_MEMNOC_GFX_CLK>;
> +		clock-names = "gmu", "cxo", "axi", "memnoc";
> +
> +		power-domains = <&gpucc GPU_CX_GDSC>;
> +		iommus = <&adreno_smmu 5>;
> +
> +		operating-points-v2 = <&gmu_opp_table>;
> +	};
> +};
> diff --git a/Documentation/devicetree/bindings/display/msm/gpu.txt b/Documentation/devicetree/bindings/display/msm/gpu.txt
> index 43fac0fe09bb..8d9415180c22 100644
> --- a/Documentation/devicetree/bindings/display/msm/gpu.txt
> +++ b/Documentation/devicetree/bindings/display/msm/gpu.txt
> @@ -8,14 +8,21 @@ Required properties:
>    with the chip-id.
>  - reg: Physical base address and length of the controller's registers.
>  - interrupts: The interrupt signal from the gpu.
> -- clocks: device clocks
> +- interrupt-names: List of names for the interrupt signals. The following can be
> +  provided:
> +  * "kgsl_3d0_irq"

I'm pretty sure 'kgsl' is not a hardware thing. You don't need *-names 
when there is only one of something.

> +- clocks: device clocks (if applicable)

What does this mean? They are now optional? If so, move to an "Optional" 
section. Likewise for the others.

Really, you should add a new compatible so we can validate when clocks 
not being present is valid vs. an error in the DT.

>    See ../clocks/clock-bindings.txt for details.
> -- clock-names: the following clocks are required:
> +- clock-names: the following clocks can be provided:
>    * "core"
>    * "iface"
>    * "mem_iface"
> +- iommus: optional phandle to an adreno iommu instance
> +- operating-points-v2: optional phandle to the OPP operating points
> +- qcom,gmu: For a6xx and newer targets a phandle to the GMU device that will
> +  control the power for the GPU
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