[PATCH 06/10] arm64: allwinner: a64: Add devicetree binding for DMA controller
From: robh@kernel.org (Rob Herring)
Date: 2017-09-12 16:52:24
Also in:
linux-devicetree, lkml
On Mon, Sep 04, 2017 at 12:40:57AM +0200, Stefan Br?ns wrote:
The A64 is register compatible with the H3, but has a different number of dma channels and request ports. Attach additional properties to the node to allow future reuse of the compatible for controllers with different number of channels/requests. If dma-requests is not specified, the register layout defined maximum of 32 is used.
This belongs in the binding.
quoted hunk ↗ jump to hunk
Signed-off-by: Stefan Br?ns <redacted> --- .../devicetree/bindings/dma/sun6i-dma.txt | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+)diff --git a/Documentation/devicetree/bindings/dma/sun6i-dma.txt b/Documentation/devicetree/bindings/dma/sun6i-dma.txt index 6b267045f522..66195fb31296 100644 --- a/Documentation/devicetree/bindings/dma/sun6i-dma.txt +++ b/Documentation/devicetree/bindings/dma/sun6i-dma.txt@@ -26,6 +26,32 @@ Example: #dma-cells = <1>; }; +------------------------------------------------------------------------------ +For A64 DMA controller: + +Required properties: +- compatible: "allwinner,sun50i-a64-dma" +- dma-channels: Number of DMA channels supported by the controller. + Refer to Documentation/devicetree/bindings/dma/dma.txt
dma.txt already explains what these properties are. You just need to state what are valid values.
+- all properties above, i.e. reg, interrupts, clocks, resets and #dma-cells
+
+Optional properties:
+- dma-requests: Number of DMA request signals supported by the controller.
+ Refer to Documentation/devicetree/bindings/dma/dma.txt
+
+Example:
+ dma: dma-controller at 01c02000 {Drop the leading 0. Building dtbs with W=2 will tell you this.
+ compatible = "allwinner,sun50i-a64-dma"; + reg = <0x01c02000 0x1000>; + interrupts = <GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&ccu CLK_BUS_DMA>; + dma-channels = <8>; + dma-requests = <27>; + resets = <&ccu RST_BUS_DMA>; + #dma-cells = <1>; + }; +------------------------------------------------------------------------------ + Clients: DMA clients connected to the A31 DMA controller must use the format -- 2.14.1