| Simon Glass | 2a80c40 | 2015-08-03 08:19:21 -0600 | [diff] [blame] | 1 | Common i2c bus multiplexer/switch properties. |
| 2 | |
| 3 | An i2c bus multiplexer/switch will have several child busses that are |
| 4 | numbered uniquely in a device dependent manner. The nodes for an i2c bus |
| 5 | multiplexer/switch will have one child node for each child |
| 6 | bus. |
| 7 | |
| 8 | Required properties: |
| 9 | - #address-cells = <1>; |
| 10 | - #size-cells = <0>; |
| 11 | |
| 12 | Required properties for child nodes: |
| 13 | - #address-cells = <1>; |
| 14 | - #size-cells = <0>; |
| 15 | - reg : The sub-bus number. |
| 16 | |
| 17 | Optional properties for child nodes: |
| 18 | - Other properties specific to the multiplexer/switch hardware. |
| 19 | - Child nodes conforming to i2c bus binding |
| 20 | |
| 21 | |
| 22 | Example : |
| 23 | |
| 24 | /* |
| 25 | An NXP pca9548 8 channel I2C multiplexer at address 0x70 |
| 26 | with two NXP pca8574 GPIO expanders attached, one each to |
| 27 | ports 3 and 4. |
| 28 | */ |
| 29 | |
| 30 | mux@70 { |
| 31 | compatible = "nxp,pca9548"; |
| 32 | reg = <0x70>; |
| 33 | #address-cells = <1>; |
| 34 | #size-cells = <0>; |
| 35 | |
| 36 | i2c@3 { |
| 37 | #address-cells = <1>; |
| 38 | #size-cells = <0>; |
| 39 | reg = <3>; |
| 40 | |
| 41 | gpio1: gpio@38 { |
| 42 | compatible = "nxp,pca8574"; |
| 43 | reg = <0x38>; |
| 44 | #gpio-cells = <2>; |
| 45 | gpio-controller; |
| 46 | }; |
| 47 | }; |
| 48 | i2c@4 { |
| 49 | #address-cells = <1>; |
| 50 | #size-cells = <0>; |
| 51 | reg = <4>; |
| 52 | |
| 53 | gpio2: gpio@38 { |
| 54 | compatible = "nxp,pca8574"; |
| 55 | reg = <0x38>; |
| 56 | #gpio-cells = <2>; |
| 57 | gpio-controller; |
| 58 | }; |
| 59 | }; |
| 60 | }; |