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Commit 374f8436 authored by Peter Rosin's avatar Peter Rosin
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dt-bindings: i2c: add support for 'i2c-mux' subnode 



Similar to the new optional 'i2c-bus' subnode from Jon Hunter, this
adds an optional 'i2c-mux' subnode, for similar reasons. I.e. it is
bad of the i2c mux core to assume that any subnode of an i2c mux device
is a potential (when the 'reg' property matches) i2c-mux child bus,
given that i2c mux devices might do more than mux i2c traffic.

So, if an 'i2c-mux' subnode is present, dictate that all i2c-mux child
buses exist beneath that subnode.

Acked-by: default avatarRob Herring <robh@kernel.org>
Reviewed-by: default avatarWolfram Sang <wsa@the-dreams.de>
Signed-off-by: default avatarPeter Rosin <peda@axentia.se>
parent fa8410b3

Documentation/devicetree/bindings/i2c/i2c-mux.txt

+18 −5
Original line number Diff line number Diff line
@@ -2,19 +2,32 @@ 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.

multiplexer/switch will have one child node for each child bus.



Required properties:

Optional properties:

- #address-cells = <1>;

   This property is required is the i2c-mux child node does not exist.



- #size-cells = <0>;

   This property is required is 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 child nodes:

Required properties for i2c child bus nodes:

- #address-cells = <1>;

- #size-cells = <0>;

- reg : The sub-bus number.



Optional properties for child nodes:

Optional properties for i2c child bus nodes:

- Other properties specific to the multiplexer/switch hardware.

- Child nodes conforming to i2c bus binding