From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- Documentation/devicetree/bindings/dma/fsl-edma.txt | 76 ++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/fsl-edma.txt (limited to 'Documentation/devicetree/bindings/dma/fsl-edma.txt') diff --git a/Documentation/devicetree/bindings/dma/fsl-edma.txt b/Documentation/devicetree/bindings/dma/fsl-edma.txt new file mode 100644 index 000000000..191d7bd8a --- /dev/null +++ b/Documentation/devicetree/bindings/dma/fsl-edma.txt @@ -0,0 +1,76 @@ +* Freescale enhanced Direct Memory Access(eDMA) Controller + + The eDMA channels have multiplex capability by programmble memory-mapped +registers. channels are split into two groups, called DMAMUX0 and DMAMUX1, +specific DMA request source can only be multiplexed by any channel of certain +group, DMAMUX0 or DMAMUX1, but not both. + +* eDMA Controller +Required properties: +- compatible : + - "fsl,vf610-edma" for eDMA used similar to that on Vybrid vf610 SoC +- reg : Specifies base physical address(s) and size of the eDMA registers. + The 1st region is eDMA control register's address and size. + The 2nd and the 3rd regions are programmable channel multiplexing + control register's address and size. +- interrupts : A list of interrupt-specifiers, one for each entry in + interrupt-names. +- interrupt-names : Should contain: + "edma-tx" - the transmission interrupt + "edma-err" - the error interrupt +- #dma-cells : Must be <2>. + The 1st cell specifies the DMAMUX(0 for DMAMUX0 and 1 for DMAMUX1). + Specific request source can only be multiplexed by specific channels + group called DMAMUX. + The 2nd cell specifies the request source(slot) ID. + See the SoC's reference manual for all the supported request sources. +- dma-channels : Number of channels supported by the controller +- clock-names : A list of channel group clock names. Should contain: + "dmamux0" - clock name of mux0 group + "dmamux1" - clock name of mux1 group +- clocks : A list of phandle and clock-specifier pairs, one for each entry in + clock-names. + +Optional properties: +- big-endian: If present registers and hardware scatter/gather descriptors + of the eDMA are implemented in big endian mode, otherwise in little + mode. + + +Examples: + +edma0: dma-controller@40018000 { + #dma-cells = <2>; + compatible = "fsl,vf610-edma"; + reg = <0x40018000 0x2000>, + <0x40024000 0x1000>, + <0x40025000 0x1000>; + interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>, + <0 9 IRQ_TYPE_LEVEL_HIGH>; + interrupt-names = "edma-tx", "edma-err"; + dma-channels = <32>; + clock-names = "dmamux0", "dmamux1"; + clocks = <&clks VF610_CLK_DMAMUX0>, + <&clks VF610_CLK_DMAMUX1>; +}; + + +* DMA clients +DMA client drivers that uses the DMA function must use the format described +in the dma.txt file, using a two-cell specifier for each channel: the 1st +specifies the channel group(DMAMUX) in which this request can be multiplexed, +and the 2nd specifies the request source. + +Examples: + +sai2: sai@40031000 { + compatible = "fsl,vf610-sai"; + reg = <0x40031000 0x1000>; + interrupts = <0 86 IRQ_TYPE_LEVEL_HIGH>; + clock-names = "sai"; + clocks = <&clks VF610_CLK_SAI2>; + dma-names = "tx", "rx"; + dmas = <&edma0 0 21>, + <&edma0 0 20>; + status = "disabled"; +}; -- cgit v1.2.3-54-g00ecf