Re: [PATCH v8 07/12] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings

From: Rob Herring
Date: Fri Jan 27 2017 - 14:40:44 EST


On Wed, Jan 18, 2017 at 04:57:10PM +0100, Peter Rosin wrote:
> Describe how a generic multiplexer controller is used to mux an i2c bus.
>
> Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
> ---
> .../devicetree/bindings/i2c/i2c-mux-simple.txt | 81 ++++++++++++++++++++++
> 1 file changed, 81 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
> new file mode 100644
> index 000000000000..253d5027843b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
> @@ -0,0 +1,81 @@
> +Simple I2C Bus Mux
> +
> +This binding describes an I2C bus multiplexer that uses a mux controller
> +from the mux subsystem to route the I2C signals.
> +
> + .-----. .-----.
> + | dev | | dev |
> + .------------. '-----' '-----'
> + | SoC | | |
> + | | .--------+--------'
> + | .------. | .------+ child bus A, on MUX value set to 0
> + | | I2C |-|--| Mux |
> + | '------' | '--+---+ child bus B, on MUX value set to 1
> + | .------. | | '----------+--------+--------.
> + | | MUX- | | | | | |
> + | | Ctrl |-|-----+ .-----. .-----. .-----.
> + | '------' | | dev | | dev | | dev |
> + '------------' '-----' '-----' '-----'
> +
> +Required properties:
> +- compatible: i2c-mux-simple,mux-locked or i2c-mux-simple,parent-locked

Not a fan of using "simple" nor the ','. Perhaps lock type should be
separate property.

I'm not sure I get the mux vs. parent locked fully. How do I determine
what type I have? We already have bindings for several types of i2c
muxes. How does the locking annotation fit into those?

Rob