| Xilinx AXI VDMA engine, it does transfers between memory and video devices. |
| It can be configured to have one channel or two channels. If configured |
| as two channels, one is to transmit to the video device and another is |
| to receive from the video device. |
| |
| Required properties: |
| - compatible: Should be "xlnx,axi-vdma-1.00.a" |
| - #dma-cells: Should be <1>, see "dmas" property below |
| - reg: Should contain VDMA registers location and length. |
| - xlnx,num-fstores: Should be the number of framebuffers as configured in h/w. |
| - dma-channel child node: Should have at least one channel and can have up to |
| two channels per device. This node specifies the properties of each |
| DMA channel (see child node properties below). |
| |
| Optional properties: |
| - xlnx,include-sg: Tells configured for Scatter-mode in |
| the hardware. |
| - xlnx,flush-fsync: Tells which channel to Flush on Frame sync. |
| It takes following values: |
| {1}, flush both channels |
| {2}, flush mm2s channel |
| {3}, flush s2mm channel |
| |
| Required child node properties: |
| - compatible: It should be either "xlnx,axi-vdma-mm2s-channel" or |
| "xlnx,axi-vdma-s2mm-channel". |
| - interrupts: Should contain per channel VDMA interrupts. |
| - xlnx,data-width: Should contain the stream data width, take values |
| {32,64...1024}. |
| |
| Optional child node properties: |
| - xlnx,include-dre: Tells hardware is configured for Data |
| Realignment Engine. |
| - xlnx,genlock-mode: Tells Genlock synchronization is |
| enabled/disabled in hardware. |
| |
| Example: |
| ++++++++ |
| |
| axi_vdma_0: axivdma@40030000 { |
| compatible = "xlnx,axi-vdma-1.00.a"; |
| #dma_cells = <1>; |
| reg = < 0x40030000 0x10000 >; |
| xlnx,num-fstores = <0x8>; |
| xlnx,flush-fsync = <0x1>; |
| dma-channel@40030000 { |
| compatible = "xlnx,axi-vdma-mm2s-channel"; |
| interrupts = < 0 54 4 >; |
| xlnx,datawidth = <0x40>; |
| } ; |
| dma-channel@40030030 { |
| compatible = "xlnx,axi-vdma-s2mm-channel"; |
| interrupts = < 0 53 4 >; |
| xlnx,datawidth = <0x40>; |
| } ; |
| } ; |
| |
| |
| * DMA client |
| |
| Required properties: |
| - dmas: a list of <[Video DMA device phandle] [Channel ID]> pairs, |
| where Channel ID is '0' for write/tx and '1' for read/rx |
| channel. |
| - dma-names: a list of DMA channel names, one per "dmas" entry |
| |
| Example: |
| ++++++++ |
| |
| vdmatest_0: vdmatest@0 { |
| compatible ="xlnx,axi-vdma-test-1.00.a"; |
| dmas = <&axi_vdma_0 0 |
| &axi_vdma_0 1>; |
| dma-names = "vdma0", "vdma1"; |
| } ; |