1 * Generic DMA Controller and DMA request bindings
3 Generic binding to provide a way for a driver using DMA Engine to retrieve the
4 DMA request or channel information that goes from a hardware device to a DMA
11 - #dma-cells: Must be at least 1. Used to provide DMA controller
12 specific information. See DMA client binding below for
16 - dma-channels: Number of DMA channels supported by the controller.
17 - dma-requests: Number of DMA request signals supported by the
19 - dma-channel-mask: Bitmask of available DMA channels in ascending order
20 that are not reserved by firmware and are available to
21 the kernel. i.e. first channel corresponds to LSB.
26 compatible = "ti,omap-sdma";
27 reg = <0x48000000 0x1000>;
28 interrupts = <0 12 0x4
35 dma-channel-mask = <0xfffe>
40 DMA routers are transparent IP blocks used to route DMA request lines from
41 devices to the DMA controller. Some SoCs (like TI DRA7x) have more peripherals
42 integrated with DMA requests than what the DMA controller can handle directly.
45 - dma-masters: phandle of the DMA controller or list of phandles for
46 the DMA controllers the router can direct the signal to.
47 - #dma-cells: Must be at least 1. Used to provide DMA router specific
48 information. See DMA client binding below for more
52 - dma-requests: Number of incoming request lines the router can handle.
53 - In the node pointed by the dma-masters:
54 - dma-requests: The router driver might need to look for this in order
55 to configure the routing.
58 sdma_xbar: dma-router@4a002b78 {
59 compatible = "ti,dra7-dma-crossbar";
60 reg = <0x4a002b78 0xfc>;
63 ti,dma-safe-map = <0>;
64 dma-masters = <&sdma>;
69 Client drivers should specify the DMA property using a phandle to the controller
70 followed by DMA controller specific data.
73 - dmas: List of one or more DMA specifiers, each consisting of
74 - A phandle pointing to DMA controller node
75 - A number of integer cells, as determined by the
76 #dma-cells property in the node referenced by phandle
77 containing DMA controller specific information. This
78 typically contains a DMA request line number or a
79 channel number, but can contain any data that is
80 required for configuring a channel.
81 - dma-names: Contains one identifier string for each DMA specifier in
82 the dmas property. The specific strings that can be used
83 are defined in the binding of the DMA client device.
84 Multiple DMA specifiers can be used to represent
85 alternatives and in this case the dma-names for those
86 DMA specifiers must be identical (see examples).
90 1. A device with one DMA read channel, one DMA write channel:
94 dmas = <&dma 2 /* read channel */
95 &dma 3>; /* write channel */
96 dma-names = "rx", "tx";
100 2. A single read-write channel with three alternative DMA controllers:
105 dma-names = "rx-tx", "rx-tx", "rx-tx";
107 3. A device with three channels, one of which has two alternatives:
109 dmas = <&dma1 2 /* read channel */
110 &dma1 3 /* write channel */
111 &dma2 0 /* error read */
112 &dma3 0>; /* alternative error read */
113 dma-names = "rx", "tx", "error", "error";