xref: /linux/Documentation/devicetree/bindings/dma/st_fdma.txt (revision 4625d2a513d60ca9c3e8cae42c8f3d9efc1b4211) 
1* STMicroelectronics Flexible Direct Memory Access Device Tree bindings
2
3The FDMA is a general-purpose direct memory access controller capable of
4supporting 16 independent DMA channels. It accepts up to 32 DMA requests.
5The FDMA is based on a Slim processor which requires a firmware.
6
7* FDMA Controller
8
9Required properties:
10- compatible	: Should be one of
11		 - st,stih407-fdma-mpe31-11, "st,slim-rproc";
12		 - st,stih407-fdma-mpe31-12, "st,slim-rproc";
13		 - st,stih407-fdma-mpe31-13, "st,slim-rproc";
14- reg		: Should contain an entry for each name in reg-names
15- reg-names	: Must contain "slimcore", "dmem", "peripherals", "imem" entries
16- interrupts	: Should contain one interrupt shared by all channels
17- dma-channels	: Number of channels supported by the controller
18- #dma-cells	: Must be <3>. See DMA client section below
19- clocks	: Must contain an entry for each clock
20See: Documentation/devicetree/bindings/clock/clock-bindings.txt
21
22
23Example:
24
25	fdma0: dma-controller@8e20000 {
26		compatible = "st,stih407-fdma-mpe31-11", "st,slim-rproc";
27		reg = <0x8e20000 0x8000>,
28		      <0x8e30000 0x3000>,
29		      <0x8e37000 0x1000>,
30		      <0x8e38000 0x8000>;
31		reg-names = "slimcore", "dmem", "peripherals", "imem";
32		clocks = <&clk_s_c0_flexgen CLK_FDMA>,
33			 <&clk_s_c0_flexgen CLK_EXT2F_A9>,
34			 <&clk_s_c0_flexgen CLK_EXT2F_A9>,
35			 <&clk_s_c0_flexgen CLK_EXT2F_A9>;
36		interrupts = <GIC_SPI 5 IRQ_TYPE_NONE>;
37		dma-channels = <16>;
38		#dma-cells = <3>;
39	};
40
41* DMA client
42
43Required properties:
44- dmas: Comma separated list of dma channel requests
45- dma-names: Names of the aforementioned requested channels
46
47Each dmas request consists of 4 cells:
481. A phandle pointing to the FDMA controller
492. The request line number
503. A 32bit mask specifying (see include/linux/platform_data/dma-st-fdma.h)
51 -bit 2-0: Holdoff value, dreq will be masked for
52	0x0: 0-0.5us
53	0x1: 0.5-1us
54	0x2: 1-1.5us
55 -bit 17: data swap
56	0x0: disabled
57	0x1: enabled
58 -bit 21: Increment Address
59	0x0: no address increment between transfers
60	0x1: increment address between transfers
61 -bit 22: 2 STBus Initiator Coprocessor interface
62	0x0: high priority port
63	0x1: low priority port
644. transfers type
65 0 free running
66 1 paced
67
68Example:
69
70	sti_uni_player2: sti-uni-player@2 {
71		compatible = "st,sti-uni-player";
72		status = "disabled";
73		#sound-dai-cells = <0>;
74		st,syscfg = <&syscfg_core>;
75		clocks = <&clk_s_d0_flexgen CLK_PCM_2>;
76		assigned-clocks = <&clk_s_d0_flexgen CLK_PCM_2>;
77		assigned-clock-parents = <&clk_s_d0_quadfs 2>;
78		assigned-clock-rates = <50000000>;
79		reg = <0x8D82000 0x158>;
80		interrupts = <GIC_SPI 86 IRQ_TYPE_NONE>;
81		dmas = <&fdma0 4 0 1>;
82		dai-name = "Uni Player #1 (DAC)";
83		dma-names = "tx";
84		st,uniperiph-id = <2>;
85		st,version = <5>;
86		st,mode = "PCM";
87	};
88