forked from Minki/linux
bc45449b14
For 'normal' i2c bus drivers, we can call of_i2c_register_devices() and have the device tree framework automatically populate the bus with the devices specified in the device tree. This patch adds a common code to the i2c mux framework to have the mux sub-busses be populated by the of_i2c_register_devices() too. If the mux device has an of_node, we populate the sub-bus' of_node so that the subsequent call to of_i2c_register_devices() will find the corresponding devices. It seemed better to put this logic in i2c_add_mux_adapter() rather than the individual mux drivers, as they will all probably want to do the same thing. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Tested-by: Lars-Peter Clausen <lars@metafoo.de> [wsa: removed superfluous ret-variable and fixed a typo in a comment] Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
61 lines
1.2 KiB
Plaintext
61 lines
1.2 KiB
Plaintext
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
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bus.
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Required properties:
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- #address-cells = <1>;
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- #size-cells = <0>;
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Required properties for child 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 child 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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