1* Ingenic JZ4780 DMA Controller 2 3Required properties: 4 5- compatible: Should be one of: 6 * ingenic,jz4740-dma 7 * ingenic,jz4725b-dma 8 * ingenic,jz4770-dma 9 * ingenic,jz4780-dma 10- reg: Should contain the DMA channel registers location and length, followed 11 by the DMA controller registers location and length. 12- interrupts: Should contain the interrupt specifier of the DMA controller. 13- clocks: Should contain a clock specifier for the JZ4780 PDMA clock. 14- #dma-cells: Must be <2>. Number of integer cells in the dmas property of 15 DMA clients (see below). 16 17Optional properties: 18 19- ingenic,reserved-channels: Bitmask of channels to reserve for devices that 20 need a specific channel. These channels will only be assigned when explicitly 21 requested by a client. The primary use for this is channels 0 and 1, which 22 can be configured to have special behaviour for NAND/BCH when using 23 programmable firmware. 24 25Example: 26 27dma: dma-controller@13420000 { 28 compatible = "ingenic,jz4780-dma"; 29 reg = <0x13420000 0x400 30 0x13421000 0x40>; 31 32 interrupt-parent = <&intc>; 33 interrupts = <10>; 34 35 clocks = <&cgu JZ4780_CLK_PDMA>; 36 37 #dma-cells = <2>; 38 39 ingenic,reserved-channels = <0x3>; 40}; 41 42DMA clients must use the format described in dma.txt, giving a phandle to the 43DMA controller plus the following 2 integer cells: 44 451. Request type: The DMA request type for transfers to/from the device on 46 the allocated channel, as defined in the SoC documentation. 47 482. Channel: If set to 0xffffffff, any available channel will be allocated for 49 the client. Otherwise, the exact channel specified will be used. The channel 50 should be reserved on the DMA controller using the ingenic,reserved-channels 51 property. 52 53Example: 54 55uart0: serial@10030000 { 56 ... 57 dmas = <&dma 0x14 0xffffffff 58 &dma 0x15 0xffffffff>; 59 dma-names = "tx", "rx"; 60 ... 61}; 62