1Common i2c bus multiplexer/switch properties. 2 3An i2c bus multiplexer/switch will have several child busses that are 4numbered uniquely in a device dependent manner. The nodes for an i2c bus 5multiplexer/switch will have one child node for each child bus. 6 7Optional properties: 8- #address-cells = <1>; 9 This property is required if the i2c-mux child node does not exist. 10 11- #size-cells = <0>; 12 This property is required if the i2c-mux child node does not exist. 13 14- i2c-mux 15 For i2c multiplexers/switches that have child nodes that are a mixture 16 of both i2c child busses and other child nodes, the 'i2c-mux' subnode 17 can be used for populating the i2c child busses. If an 'i2c-mux' 18 subnode is present, only subnodes of this will be considered as i2c 19 child busses. 20 21Required properties for the i2c-mux child node: 22- #address-cells = <1>; 23- #size-cells = <0>; 24 25Required properties for i2c child bus nodes: 26- #address-cells = <1>; 27- #size-cells = <0>; 28- reg : The sub-bus number. 29 30Optional properties for i2c child bus nodes: 31- Other properties specific to the multiplexer/switch hardware. 32- Child nodes conforming to i2c bus binding 33 34 35Example : 36 37 /* 38 An NXP pca9548 8 channel I2C multiplexer at address 0x70 39 with two NXP pca8574 GPIO expanders attached, one each to 40 ports 3 and 4. 41 */ 42 43 mux@70 { 44 compatible = "nxp,pca9548"; 45 reg = <0x70>; 46 #address-cells = <1>; 47 #size-cells = <0>; 48 49 i2c@3 { 50 #address-cells = <1>; 51 #size-cells = <0>; 52 reg = <3>; 53 54 gpio1: gpio@38 { 55 compatible = "nxp,pca8574"; 56 reg = <0x38>; 57 #gpio-cells = <2>; 58 gpio-controller; 59 }; 60 }; 61 i2c@4 { 62 #address-cells = <1>; 63 #size-cells = <0>; 64 reg = <4>; 65 66 gpio2: gpio@38 { 67 compatible = "nxp,pca8574"; 68 reg = <0x38>; 69 #gpio-cells = <2>; 70 gpio-controller; 71 }; 72 }; 73 }; 74