68 lines
2.1 KiB
Plaintext
68 lines
2.1 KiB
Plaintext
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* Synopsys Designware DMA Controller
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Required properties:
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- compatible: "snps,dma-spear1340"
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- reg: Address range of the DMAC registers
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- interrupt: Should contain the DMAC interrupt number
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- dma-channels: Number of channels supported by hardware
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- dma-requests: Number of DMA request lines supported, up to 16
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- dma-masters: Number of AHB masters supported by the controller
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- #dma-cells: must be <3>
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- chan_allocation_order: order of allocation of channel, 0 (default): ascending,
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1: descending
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- chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1:
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increase from chan n->0
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- block_size: Maximum block size supported by the controller
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- data-width: Maximum data width supported by hardware per AHB master
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(in bytes, power of 2)
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Deprecated properties:
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- data_width: Maximum data width supported by hardware per AHB master
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(0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
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Optional properties:
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- is_private: The device channels should be marked as private and not for by the
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general purpose DMA channel allocator. False if not passed.
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- multi-block: Multi block transfers supported by hardware. Array property with
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one cell per channel. 0: not supported, 1 (default): supported.
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Example:
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dmahost: dma@fc000000 {
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compatible = "snps,dma-spear1340";
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reg = <0xfc000000 0x1000>;
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interrupt-parent = <&vic1>;
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interrupts = <12>;
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dma-channels = <8>;
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dma-requests = <16>;
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dma-masters = <2>;
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#dma-cells = <3>;
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chan_allocation_order = <1>;
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chan_priority = <1>;
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block_size = <0xfff>;
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data-width = <8 8>;
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};
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DMA clients connected to the Designware DMA controller must use the format
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described in the dma.txt file, using a four-cell specifier for each channel.
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The four cells in order are:
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1. A phandle pointing to the DMA controller
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2. The DMA request line number
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3. Memory master for transfers on allocated channel
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4. Peripheral master for transfers on allocated channel
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Example:
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serial@e0000000 {
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compatible = "arm,pl011", "arm,primecell";
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reg = <0xe0000000 0x1000>;
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interrupts = <0 35 0x4>;
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dmas = <&dmahost 12 0 1>,
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<&dmahost 13 1 0>;
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dma-names = "rx", "rx";
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};
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