From c8307106f5fa53b8fe8763b488d629e3cce9fae3 Mon Sep 17 00:00:00 2001 From: Alex Smith Date: Wed, 18 Mar 2015 16:16:35 +0000 Subject: dt-bindings: dma: Add binding for jz4780-dma Add device tree bindings for the DMA controller on JZ4780 SoCs, used by the dma-jz4780 driver. Signed-off-by: Alex Smith Signed-off-by: Zubair Lutfullah Kakakhel Signed-off-by: Vinod Koul --- .../devicetree/bindings/dma/jz4780-dma.txt | 56 ++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/jz4780-dma.txt diff --git a/Documentation/devicetree/bindings/dma/jz4780-dma.txt b/Documentation/devicetree/bindings/dma/jz4780-dma.txt new file mode 100644 index 000000000000..f25feee62b15 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/jz4780-dma.txt @@ -0,0 +1,56 @@ +* Ingenic JZ4780 DMA Controller + +Required properties: + +- compatible: Should be "ingenic,jz4780-dma" +- reg: Should contain the DMA controller registers location and length. +- interrupts: Should contain the interrupt specifier of the DMA controller. +- interrupt-parent: Should be the phandle of the interrupt controller that +- clocks: Should contain a clock specifier for the JZ4780 PDMA clock. +- #dma-cells: Must be <2>. Number of integer cells in the dmas property of + DMA clients (see below). + +Optional properties: + +- ingenic,reserved-channels: Bitmask of channels to reserve for devices that + need a specific channel. These channels will only be assigned when explicitly + requested by a client. The primary use for this is channels 0 and 1, which + can be configured to have special behaviour for NAND/BCH when using + programmable firmware. + +Example: + +dma: dma@13420000 { + compatible = "ingenic,jz4780-dma"; + reg = <0x13420000 0x10000>; + + interrupt-parent = <&intc>; + interrupts = <10>; + + clocks = <&cgu JZ4780_CLK_PDMA>; + + #dma-cells = <2>; + + ingenic,reserved-channels = <0x3>; +}; + +DMA clients must use the format described in dma.txt, giving a phandle to the +DMA controller plus the following 2 integer cells: + +1. Request type: The DMA request type for transfers to/from the device on + the allocated channel, as defined in the SoC documentation. + +2. Channel: If set to 0xffffffff, any available channel will be allocated for + the client. Otherwise, the exact channel specified will be used. The channel + should be reserved on the DMA controller using the ingenic,reserved-channels + property. + +Example: + +uart0: serial@10030000 { + ... + dmas = <&dma 0x14 0xffffffff + &dma 0x15 0xffffffff>; + dma-names = "tx", "rx"; + ... +}; -- cgit v1.2.3