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73 lines
1.8 KiB
73 lines
1.8 KiB
Common i2c bus multiplexer/switch properties. |
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An i2c bus multiplexer/switch will have several child busses that are |
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numbered uniquely in a device dependent manner. The nodes for an i2c bus |
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multiplexer/switch will have one child node for each child bus. |
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Optional properties: |
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- #address-cells = <1>; |
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This property is required if the i2c-mux child node does not exist. |
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- #size-cells = <0>; |
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This property is required if the i2c-mux child node does not exist. |
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- i2c-mux |
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For i2c multiplexers/switches that have child nodes that are a mixture |
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of both i2c child busses and other child nodes, the 'i2c-mux' subnode |
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can be used for populating the i2c child busses. If an 'i2c-mux' |
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subnode is present, only subnodes of this will be considered as i2c |
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child busses. |
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Required properties for the i2c-mux child node: |
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- #address-cells = <1>; |
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- #size-cells = <0>; |
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Required properties for i2c child bus nodes: |
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- #address-cells = <1>; |
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- #size-cells = <0>; |
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- reg : The sub-bus number. |
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Optional properties for i2c child bus nodes: |
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- Other properties specific to the multiplexer/switch hardware. |
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- Child nodes conforming to i2c bus binding |
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Example : |
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/* |
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An NXP pca9548 8 channel I2C multiplexer at address 0x70 |
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with two NXP pca8574 GPIO expanders attached, one each to |
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ports 3 and 4. |
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*/ |
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mux@70 { |
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compatible = "nxp,pca9548"; |
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reg = <0x70>; |
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#address-cells = <1>; |
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#size-cells = <0>; |
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i2c@3 { |
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#address-cells = <1>; |
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#size-cells = <0>; |
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reg = <3>; |
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gpio1: gpio@38 { |
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compatible = "nxp,pca8574"; |
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reg = <0x38>; |
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#gpio-cells = <2>; |
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gpio-controller; |
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}; |
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}; |
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i2c@4 { |
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#address-cells = <1>; |
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#size-cells = <0>; |
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reg = <4>; |
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gpio2: gpio@38 { |
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compatible = "nxp,pca8574"; |
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reg = <0x38>; |
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#gpio-cells = <2>; |
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gpio-controller; |
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}; |
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}; |
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};
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