xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/i2c/i2c-mux.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunCommon i2c bus multiplexer/switch properties.
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunAn i2c bus multiplexer/switch will have several child busses that are
4*4882a593Smuzhiyunnumbered uniquely in a device dependent manner.  The nodes for an i2c bus
5*4882a593Smuzhiyunmultiplexer/switch will have one child node for each child
6*4882a593Smuzhiyunbus.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunRequired properties:
9*4882a593Smuzhiyun- #address-cells = <1>;
10*4882a593Smuzhiyun- #size-cells = <0>;
11*4882a593Smuzhiyun
12*4882a593SmuzhiyunRequired properties for child nodes:
13*4882a593Smuzhiyun- #address-cells = <1>;
14*4882a593Smuzhiyun- #size-cells = <0>;
15*4882a593Smuzhiyun- reg : The sub-bus number.
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunOptional properties for child nodes:
18*4882a593Smuzhiyun- Other properties specific to the multiplexer/switch hardware.
19*4882a593Smuzhiyun- Child nodes conforming to i2c bus binding
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunExample :
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun	/*
25*4882a593Smuzhiyun	   An NXP pca9548 8 channel I2C multiplexer at address 0x70
26*4882a593Smuzhiyun	   with two NXP pca8574 GPIO expanders attached, one each to
27*4882a593Smuzhiyun	   ports 3 and 4.
28*4882a593Smuzhiyun	 */
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun	mux@70 {
31*4882a593Smuzhiyun		compatible = "nxp,pca9548";
32*4882a593Smuzhiyun		reg = <0x70>;
33*4882a593Smuzhiyun		#address-cells = <1>;
34*4882a593Smuzhiyun		#size-cells = <0>;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun		i2c@3 {
37*4882a593Smuzhiyun			#address-cells = <1>;
38*4882a593Smuzhiyun			#size-cells = <0>;
39*4882a593Smuzhiyun			reg = <3>;
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun			gpio1: gpio@38 {
42*4882a593Smuzhiyun				compatible = "nxp,pca8574";
43*4882a593Smuzhiyun				reg = <0x38>;
44*4882a593Smuzhiyun				#gpio-cells = <2>;
45*4882a593Smuzhiyun				gpio-controller;
46*4882a593Smuzhiyun			};
47*4882a593Smuzhiyun		};
48*4882a593Smuzhiyun		i2c@4 {
49*4882a593Smuzhiyun			#address-cells = <1>;
50*4882a593Smuzhiyun			#size-cells = <0>;
51*4882a593Smuzhiyun			reg = <4>;
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun			gpio2: gpio@38 {
54*4882a593Smuzhiyun				compatible = "nxp,pca8574";
55*4882a593Smuzhiyun				reg = <0x38>;
56*4882a593Smuzhiyun				#gpio-cells = <2>;
57*4882a593Smuzhiyun				gpio-controller;
58*4882a593Smuzhiyun			};
59*4882a593Smuzhiyun		};
60*4882a593Smuzhiyun	};
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