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Diffstat (limited to 'Documentation/devicetree/bindings/dma/snps-dma.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/dma/snps-dma.txt | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt index c0d85dbcada..d58675ea1ab 100644 --- a/Documentation/devicetree/bindings/dma/snps-dma.txt +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt @@ -3,15 +3,61 @@ 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 -- interrupt: Should contain the DMAC interrupt number +- 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: - dma@fc000000 { + 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 0 0>; + }; + +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"; }; |