From a3d3044e7d0af3c47ebe6300653edc4203665c5f Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Wed, 22 Oct 2014 17:22:19 +0200 Subject: [PATCH] ARM: dts: at_xdmac: add bindings documentation Add bindings documentation for the new Atmel DMA controller (XDMAC) introduced with SAMA5D4. Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre Signed-off-by: Vinod Koul --- .../devicetree/bindings/dma/atmel-xdma.txt | 54 +++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt new file mode 100644 index 000000000000..e75c128c53fa --- /dev/null +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt @@ -0,0 +1,54 @@ +* Atmel Extensible Direct Memory Access Controller (XDMAC) + +* XDMA Controller +Required properties: +- compatible: Should be "atmel,-dma". + compatible description: + - sama5d4: first SoC adding the XDMAC +- reg: Should contain DMA registers location and length. +- interrupts: Should contain DMA interrupt. +- #dma-cells: Must be <1>, used to represent the number of integer cells in +the dmas property of client devices. + - The 1st cell specifies the channel configuration register: + - bit 13: SIF, source interface identifier, used to get the memory + interface identifier, + - bit 14: DIF, destination interface identifier, used to get the peripheral + interface identifier, + - bit 30-24: PERID, peripheral identifier. + +Example: + +dma1: dma-controller@f0004000 { + compatible = "atmel,sama5d4-dma"; + reg = <0xf0004000 0x200>; + interrupts = <50 4 0>; + #dma-cells = <2>; +}; + + +* DMA clients +DMA clients connected to the Atmel XDMA controller must use the format +described in the dma.txt file, using a one-cell specifier for each channel. +The two cells in order are: +1. A phandle pointing to the DMA controller. +2. Channel configuration register. Configurable fields are: + - bit 13: SIF, source interface identifier, used to get the memory + interface identifier, + - bit 14: DIF, destination interface identifier, used to get the peripheral + interface identifier, + - bit 30-24: PERID, peripheral identifier. + +Example: + +i2c2: i2c@f8024000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8024000 0x4000>; + interrupts = <34 4 6>; + dmas = <&dma1 + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1) + | AT91_XDMAC_DT_PERID(6))>, + <&dma1 + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1) + | AT91_XDMAC_DT_PERID(7))>; + dma-names = "tx", "rx"; +};