linux/Documentation/devicetree/bindings/display/arm,komeda.txt
james qian wang (Arm Technology China) 619053220a dt/bindings: drm/komeda: Unify mclk/pclk/pipeline->aclk to one ACLK
Current komeda driver uses three dedicated clks for a specific purpose:
- mclk: main engine clock
- pclk: APB clock
- pipeline->aclk: AXI clock.

But per spec the komeda HW only has three input clks:
- ACLK: used for AXI masters, APB slave and most pipeline processing
- PXCLK for pipeline 0: output pixel clock for pipeline 0
- PXCLK for pipeline 1: output pixel clock for pipeline 1

So one ACLK is enough, no need to split it to three mclk/pclk/axiclk.

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
2019-06-19 11:42:17 +01:00

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Device Tree bindings for Arm Komeda display driver
Required properties:
- compatible: Should be "arm,mali-d71"
- reg: Physical base address and length of the registers in the system
- interrupts: the interrupt line number of the device in the system
- clocks: A list of phandle + clock-specifier pairs, one for each entry
in 'clock-names'
- clock-names: A list of clock names. It should contain:
- "aclk": for the main processor clock
- #address-cells: Must be 1
- #size-cells: Must be 0
- iommus: configure the stream id to IOMMU, Must be configured if want to
enable iommu in display. for how to configure this node please reference
devicetree/bindings/iommu/arm,smmu-v3.txt,
devicetree/bindings/iommu/iommu.txt
Required properties for sub-node: pipeline@nq
Each device contains one or two pipeline sub-nodes (at least one), each
pipeline node should provide properties:
- reg: Zero-indexed identifier for the pipeline
- clocks: A list of phandle + clock-specifier pairs, one for each entry
in 'clock-names'
- clock-names: should contain:
- "pxclk": pixel clock
- port: each pipeline connect to an encoder input port. The connection is
modeled using the OF graph bindings specified in
Documentation/devicetree/bindings/graph.txt
Optional properties:
- memory-region: phandle to a node describing memory (see
Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt)
to be used for the framebuffer; if not present, the framebuffer may
be located anywhere in memory.
Example:
/ {
...
dp0: display@c00000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "arm,mali-d71";
reg = <0xc00000 0x20000>;
interrupts = <0 168 4>;
clocks = <&dpu_aclk>;
clock-names = "aclk";
iommus = <&smmu 0>, <&smmu 1>, <&smmu 2>, <&smmu 3>,
<&smmu 4>, <&smmu 5>, <&smmu 6>, <&smmu 7>,
<&smmu 8>, <&smmu 9>;
dp0_pipe0: pipeline@0 {
clocks = <&fpgaosc2>;
clock-names = "pxclk";
reg = <0>;
port {
dp0_pipe0_out: endpoint {
remote-endpoint = <&db_dvi0_in>;
};
};
};
dp0_pipe1: pipeline@1 {
clocks = <&fpgaosc2>;
clock-names = "pxclk";
reg = <1>;
port {
dp0_pipe1_out: endpoint {
remote-endpoint = <&db_dvi1_in>;
};
};
};
};
...
};