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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/i2c/i2c-mux.txt | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-mux.txt')
-rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-mux.txt | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux.txt b/Documentation/devicetree/bindings/i2c/i2c-mux.txt new file mode 100644 index 000000000..b38f58a1c --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-mux.txt @@ -0,0 +1,73 @@ +Common i2c bus multiplexer/switch properties. + +An i2c bus multiplexer/switch will have several child busses that are +numbered uniquely in a device dependent manner. The nodes for an i2c bus +multiplexer/switch will have one child node for each child bus. + +Optional properties: +- #address-cells = <1>; + This property is required if the i2c-mux child node does not exist. + +- #size-cells = <0>; + This property is required if the i2c-mux child node does not exist. + +- i2c-mux + For i2c multiplexers/switches that have child nodes that are a mixture + of both i2c child busses and other child nodes, the 'i2c-mux' subnode + can be used for populating the i2c child busses. If an 'i2c-mux' + subnode is present, only subnodes of this will be considered as i2c + child busses. + +Required properties for the i2c-mux child node: +- #address-cells = <1>; +- #size-cells = <0>; + +Required properties for i2c child bus nodes: +- #address-cells = <1>; +- #size-cells = <0>; +- reg : The sub-bus number. + +Optional properties for i2c child bus nodes: +- Other properties specific to the multiplexer/switch hardware. +- Child nodes conforming to i2c bus binding + + +Example : + + /* + An NXP pca9548 8 channel I2C multiplexer at address 0x70 + with two NXP pca8574 GPIO expanders attached, one each to + ports 3 and 4. + */ + + mux@70 { + compatible = "nxp,pca9548"; + reg = <0x70>; + #address-cells = <1>; + #size-cells = <0>; + + i2c@3 { + #address-cells = <1>; + #size-cells = <0>; + reg = <3>; + + gpio1: gpio@38 { + compatible = "nxp,pca8574"; + reg = <0x38>; + #gpio-cells = <2>; + gpio-controller; + }; + }; + i2c@4 { + #address-cells = <1>; + #size-cells = <0>; + reg = <4>; + + gpio2: gpio@38 { + compatible = "nxp,pca8574"; + reg = <0x38>; + #gpio-cells = <2>; + gpio-controller; + }; + }; + }; |