[PATCH V3 2/7] documentation: iommu: Add bindings for msm,iommu-v0 ip

[robh@kernel.org (Rob Herring)]

On Mon, May 02, 2016 at 12:24:30AM +0530, Sricharan R wrote:
> The MSM IOMMU is an implementation compatible with the ARM VMSA short
> descriptor page tables. It provides address translation for bus masters outside
> of the CPU, each connected to the IOMMU through a port called micro-TLB.
> Adding the DT bindings for the same.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  .../devicetree/bindings/iommu/msm,iommu-v0.txt     | 62 ++++++++++++++++++++++
>  1 file changed, 62 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt
> 
> diff --git a/Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt b/Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt
> new file mode 100644
> index 0000000..63b4f96
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iommu/msm,iommu-v0.txt
> @@ -0,0 +1,62 @@
> +* MSM IOMMU
> +
> +The MSM IOMMU is an implementation compatible with the ARM VMSA short
> +descriptor page tables. It provides address translation for bus masters outside
> +of the CPU, each connected to the IOMMU through a port called micro-TLB.
> +
> +Required Properties:
> +
> +  - compatible: Must contain "msm,iommu-v0".

SOC specific compatible strings please.

> +  - reg: Base address and size of the IOMMU registers.
> +  - interrupts: Specifiers for the MMU fault interrupts. For instances that
> +    support secure mode two interrupts must be specified, for non-secure and
> +    secure mode, in that order. For instances that don't support secure mode a
> +    single interrupt must be specified.
> +  - #iommu-cells: The number of cells needed to specify the stream id. This
> +		  is always 1.
> +  - qcom,ncb:	  The total number of context banks in the IOMMU.
> +  - clocks	: List of clocks to be used during SMMU register access. See
> +		  Documentation/devicetree/bindings/clock/clock-bindings.txt
> +		  for information about the format. For each clock specified
> +		  here, there must be a corresponding entry in clock-names
> +		  (see below).
> +
> +  - clock-names	: List of clock names corresponding to the clocks specified in
> +		  the "clocks" property (above). See
> +		  Documentation/devicetree/bindings/clock/clock-bindings.txt
> +		  for more info.

You must define how many clocks, their order and their names.

> +
> +Each bus master connected to an IOMMU must reference the IOMMU in its device
> +node with the following property:
> +
> +  - iommus: A reference to the IOMMU in multiple cells. The first cell is a
> +	    phandle to the IOMMU and the second cell is the stream id.
> +	    A single master device can be connected to more than one iommu
> +	    and multiple contexts in each of the iommu. So multiple entries
> +	    are required to list all the iommus and the stream ids that the
> +	    master is connected to.
> +
> +Example: mdp iommu and its bus master
> +
> +                mdp_port0: iommu at 7500000 {
> +			compatible = "msm,iommu-v0";
> +			#iommu-cells = <1>;
> +			clock-names =
> +			    "smmu_pclk",
> +			    "iommu_clk";
> +			clocks =
> +			    <&mmcc SMMU_AHB_CLK>,
> +			    <&mmcc MDP_AXI_CLK>;
> +			reg = <0x07500000 0x100000>;
> +			interrupts =
> +			    <GIC_SPI 63 0>,
> +			    <GIC_SPI 64 0>;
> +			qcom,ncb = <2>;
> +		};
> +
> +		mdp: qcom,mdp at 5100000 {
> +			compatible = "qcom,mdp";
> +			...
> +			iommus = <&mdp_port0 0
> +				  &mdp_port0 2>;
> +		};
> -- 
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> 
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