Kernel-3.10.0-957.el7_snps-dma

• Synopsys Designware DMA Controller

Required properties:

• compatible: “snps,dma-spear1340”
• reg: Address range of the DMAC registers
• interrupt: Should contain the DMAC interrupt number
• dma-channels: Number of channels supported by hardware
• dma-requests: Number of DMA request lines supported, up to 16
• dma-masters: Number of AHB masters supported by the controller
• #dma-cells: must be <3>
• chan_allocation_order: order of allocation of channel, 0 (default): ascending,
  1: descending
• chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1:
  increase from chan n->0
• block_size: Maximum block size supported by the controller
• data_width: Maximum data width supported by hardware per AHB master
  (0 - 8bits, 1 - 16bits, …, 5 - 256bits)

Optional properties:

• interrupt-parent: Should be the phandle for the interrupt controller
  that services interrupts for this device
• is_private: The device channels should be marked as private and not for by the
  general purpose DMA channel allocator. False if not passed.

Example:

dmahost: dma@fc000000 {
    compatible = "snps,dma-spear1340";
    reg = <0xfc000000 0x1000>;
    interrupt-parent = <&vic1>;
    interrupts = <12>;

    dma-channels = <8>;
    dma-requests = <16>;
    dma-masters = <2>;
    #dma-cells = <3>;
    chan_allocation_order = <1>;
    chan_priority = <1>;
    block_size = <0xfff>;
    data_width = <3 3>;
};

DMA clients connected to the Designware DMA controller must use the format
described in the dma.txt file, using a four-cell specifier for each channel.
The four cells in order are:

1. A phandle pointing to the DMA controller
2. The DMA request line number
3. Source master for transfers on allocated channel
4. Destination master for transfers on allocated channel

Example:

serial@e0000000 {
    compatible = "arm,pl011", "arm,primecell";
    reg = <0xe0000000 0x1000>;
    interrupts = <0 35 0x4>;
    status = "disabled";
    dmas = <&dmahost 12 0 1>,
        <&dmahost 13 0 1 0>;
    dma-names = "rx", "rx";
};