1* SHDMA Device Tree bindings
2
3Sh-/r-mobile and R-Car systems often have multiple identical DMA controller
4instances, capable of serving any of a common set of DMA slave devices, using
5the same configuration. To describe this topology we require all compatible
6SHDMA DT nodes to be placed under a DMA multiplexer node. All such compatible
7DMAC instances have the same number of channels and use the same DMA
8descriptors. Therefore respective DMA DT bindings can also all be placed in the
9multiplexer node. Even if there is only one such DMAC instance on a system, it
10still has to be placed under such a multiplexer node.
11
12* DMA multiplexer
13
14Required properties:
15- compatible:	should be "renesas,shdma-mux"
16- #dma-cells:	should be <1>, see "dmas" property below
17
18Optional properties (currently unused):
19- dma-channels:	number of DMA channels
20- dma-requests:	number of DMA request signals
21
22* DMA controller
23
24Required properties:
25- compatible:	should be of the form "renesas,shdma-<soc>", where <soc> should
26		be replaced with the desired SoC model, e.g.
27		"renesas,shdma-r8a73a4" for the system DMAC on r8a73a4 SoC
28
29Example:
30	dmac: dma-multiplexer@0 {
31		compatible = "renesas,shdma-mux";
32		#dma-cells = <1>;
33		dma-channels = <20>;
34		dma-requests = <256>;
35		#address-cells = <2>;
36		#size-cells = <2>;
37		ranges;
38
39		dma0: dma-controller@e6700020 {
40			compatible = "renesas,shdma-r8a73a4";
41			reg = <0 0xe6700020 0 0x89e0>;
42			interrupt-parent = <&gic>;
43			interrupts = <0 220 4
44					0 200 4
45					0 201 4
46					0 202 4
47					0 203 4
48					0 204 4
49					0 205 4
50					0 206 4
51					0 207 4
52					0 208 4
53					0 209 4
54					0 210 4
55					0 211 4
56					0 212 4
57					0 213 4
58					0 214 4
59					0 215 4
60					0 216 4
61					0 217 4
62					0 218 4
63					0 219 4>;
64			interrupt-names = "error",
65					"ch0", "ch1", "ch2", "ch3",
66					"ch4", "ch5", "ch6", "ch7",
67					"ch8", "ch9", "ch10", "ch11",
68					"ch12", "ch13", "ch14", "ch15",
69					"ch16", "ch17", "ch18", "ch19";
70		};
71	};
72
73* DMA client
74
75Required properties:
76- dmas:		a list of <[DMA multiplexer phandle] [MID/RID value]> pairs,
77		where MID/RID values are fixed handles, specified in the SoC
78		manual
79- dma-names:	a list of DMA channel names, one per "dmas" entry
80
81Example:
82	dmas = <&dmac 0xd1
83		&dmac 0xd2>;
84	dma-names = "tx", "rx";
85