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Diffstat (limited to 'dts/upstream/Bindings/dma/xilinx/xilinx_dma.txt')
-rw-r--r-- | dts/upstream/Bindings/dma/xilinx/xilinx_dma.txt | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/dts/upstream/Bindings/dma/xilinx/xilinx_dma.txt b/dts/upstream/Bindings/dma/xilinx/xilinx_dma.txt new file mode 100644 index 00000000000..590d1948f20 --- /dev/null +++ b/dts/upstream/Bindings/dma/xilinx/xilinx_dma.txt @@ -0,0 +1,134 @@ +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. + +Xilinx AXI DMA engine, it does transfers between memory and AXI4 stream +target devices. It can be configured to have one channel or two channels. +If configured as two channels, one is to transmit to the device and another +is to receive from the device. + +Xilinx AXI CDMA engine, it does transfers between memory-mapped source +address and a memory-mapped destination address. + +Xilinx AXI MCDMA engine, it does transfer between memory and AXI4 stream +target devices. It can be configured to have up to 16 independent transmit +and receive channels. + +Required properties: +- compatible: Should be one of- + "xlnx,axi-vdma-1.00.a" + "xlnx,axi-dma-1.00.a" + "xlnx,axi-cdma-1.00.a" + "xlnx,axi-mcdma-1.00.a" +- #dma-cells: Should be <1>, see "dmas" property below +- reg: Should contain VDMA registers location and length. +- xlnx,addrwidth: Should be the vdma addressing size in bits(ex: 32 bits). +- dma-ranges: Should be as the following <dma_addr cpu_addr max_len>. +- 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). +- clocks: Input clock specifier. Refer to common clock bindings. +- clock-names: List of input clocks + For VDMA: + Required elements: "s_axi_lite_aclk" + Optional elements: "m_axi_mm2s_aclk" "m_axi_s2mm_aclk", + "m_axis_mm2s_aclk", "s_axis_s2mm_aclk" + For CDMA: + Required elements: "s_axi_lite_aclk", "m_axi_aclk" + For AXIDMA and MCDMA: + Required elements: "s_axi_lite_aclk" + Optional elements: "m_axi_mm2s_aclk", "m_axi_s2mm_aclk", + "m_axi_sg_aclk" + +Required properties for VDMA: +- xlnx,num-fstores: Should be the number of framebuffers as configured in h/w. + +Optional properties for AXI DMA and MCDMA: +- xlnx,sg-length-width: Should be set to the width in bits of the length + register as configured in h/w. Takes values {8...26}. If the property + is missing or invalid then the default value 23 is used. This is the + maximum value that is supported by all IP versions. + +Optional properties for AXI DMA: +- xlnx,axistream-connected: Tells whether DMA is connected to AXI stream IP. +- xlnx,irq-delay: Tells the interrupt delay timeout value. Valid range is from + 0-255. Setting this value to zero disables the delay timer interrupt. + 1 timeout interval = 125 * clock period of SG clock. +Optional properties for VDMA: +- 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: + For VDMA: It should be either "xlnx,axi-vdma-mm2s-channel" or + "xlnx,axi-vdma-s2mm-channel". + For CDMA: It should be "xlnx,axi-cdma-channel". + For AXIDMA and MCDMA: It should be either "xlnx,axi-dma-mm2s-channel" + or "xlnx,axi-dma-s2mm-channel". +- interrupts: Should contain per channel VDMA interrupts. +- xlnx,datawidth: 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. +Optional child node properties for VDMA: +- xlnx,genlock-mode: Tells Genlock synchronization is + enabled/disabled in hardware. +- xlnx,enable-vert-flip: Tells vertical flip is + enabled/disabled in hardware(S2MM path). +Optional child node properties for MCDMA: +- dma-channels: Number of dma channels in child node. + +Example: +++++++++ + +axi_vdma_0: axivdma@40030000 { + compatible = "xlnx,axi-vdma-1.00.a"; + #dma_cells = <1>; + reg = < 0x40030000 0x10000 >; + dma-ranges = <0x00000000 0x00000000 0x40000000>; + xlnx,num-fstores = <0x8>; + xlnx,flush-fsync = <0x1>; + xlnx,addrwidth = <0x20>; + clocks = <&clk 0>, <&clk 1>, <&clk 2>, <&clk 3>, <&clk 4>; + clock-names = "s_axi_lite_aclk", "m_axi_mm2s_aclk", "m_axi_s2mm_aclk", + "m_axis_mm2s_aclk", "s_axis_s2mm_aclk"; + 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. For MCMDA, MM2S channel(write/tx) ID start from + '0' and is in [0-15] range. S2MM channel(read/rx) ID start + from '16' and is in [16-31] range. These channels ID are + fixed irrespective of IP configuration. + +- 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"; +} ; |