i2c: document binding for multi-master case

We need this binding because some I2C master drivers will need to adapt
their PM settings for the arbitration circuitry.

Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/Documentation/devicetree/bindings/i2c/i2c.txt b/Documentation/devicetree/bindings/i2c/i2c.txt
index a00219f..c8d977e 100644 (file)
--- a/Documentation/devicetree/bindings/i2c/i2c.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c.txt
@@ -54,6 +54,11 @@ wants to support one of the below features, it should adapt the bindings below.
        "irq" and "wakeup" names are recognized by I2C core, other names are
        left to individual drivers.
 
+- multi-master
+       states that there is another master active on this bus. The OS can use
+       this information to adapt power management to keep the arbitration awake
+       all the time, for example.
+
 - wakeup-source
        device can be used as a wakeup source.