xref: /freebsd/sys/contrib/device-tree/Bindings/mux/reg-mux.txt (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc) 
1Generic register bitfield-based multiplexer controller bindings
2
3Define register bitfields to be used to control multiplexers. The parent
4device tree node must be a device node to provide register r/w access.
5
6Required properties:
7- compatible : should be one of
8	"reg-mux" : if parent device of mux controller is not syscon device
9	"mmio-mux" : if parent device of mux controller is syscon device
10- #mux-control-cells : <1>
11- mux-reg-masks : an array of register offset and pre-shifted bitfield mask
12                  pairs, each describing a single mux control.
13* Standard mux-controller bindings as decribed in mux-controller.txt
14
15Optional properties:
16- idle-states : if present, the state the muxes will have when idle. The
17		special state MUX_IDLE_AS_IS is the default.
18
19The multiplexer state of each multiplexer is defined as the value of the
20bitfield described by the corresponding register offset and bitfield mask
21pair in the mux-reg-masks array.
22
23Example 1:
24The parent device of mux controller is not a syscon device.
25
26&i2c0 {
27	fpga@66 { // fpga connected to i2c
28		compatible = "fsl,lx2160aqds-fpga", "fsl,fpga-qixis-i2c",
29			     "simple-mfd";
30		reg = <0x66>;
31
32		mux: mux-controller {
33			compatible = "reg-mux";
34			#mux-control-cells = <1>;
35			mux-reg-masks = <0x54 0xf8>, /* 0: reg 0x54, bits 7:3 */
36					<0x54 0x07>; /* 1: reg 0x54, bits 2:0 */
37		};
38	};
39};
40
41mdio-mux-1 {
42	compatible = "mdio-mux-multiplexer";
43	mux-controls = <&mux 0>;
44	mdio-parent-bus = <&emdio1>;
45	#address-cells = <1>;
46	#size-cells = <0>;
47
48	mdio@0 {
49		reg = <0x0>;
50		#address-cells = <1>;
51		#size-cells = <0>;
52	};
53
54	mdio@8 {
55		reg = <0x8>;
56		#address-cells = <1>;
57		#size-cells = <0>;
58	};
59
60	..
61	..
62};
63
64mdio-mux-2 {
65	compatible = "mdio-mux-multiplexer";
66	mux-controls = <&mux 1>;
67	mdio-parent-bus = <&emdio2>;
68	#address-cells = <1>;
69	#size-cells = <0>;
70
71	mdio@0 {
72		reg = <0x0>;
73		#address-cells = <1>;
74		#size-cells = <0>;
75	};
76
77	mdio@1 {
78		reg = <0x1>;
79		#address-cells = <1>;
80		#size-cells = <0>;
81	};
82
83	..
84	..
85};
86
87Example 2:
88The parent device of mux controller is syscon device.
89
90syscon {
91	compatible = "syscon";
92
93	mux: mux-controller {
94		compatible = "mmio-mux";
95		#mux-control-cells = <1>;
96
97		mux-reg-masks = <0x3 0x30>, /* 0: reg 0x3, bits 5:4 */
98				<0x3 0x40>, /* 1: reg 0x3, bit 6 */
99		idle-states = <MUX_IDLE_AS_IS>, <0>;
100	};
101};
102
103video-mux {
104	compatible = "video-mux";
105	mux-controls = <&mux 0>;
106	#address-cells = <1>;
107	#size-cells = <0>;
108
109	ports {
110		/* inputs 0..3 */
111		port@0 {
112			reg = <0>;
113		};
114		port@1 {
115			reg = <1>;
116		};
117		port@2 {
118			reg = <2>;
119		};
120		port@3 {
121			reg = <3>;
122		};
123
124		/* output */
125		port@4 {
126			reg = <4>;
127		};
128	};
129};
130