[PATCH v2 1/3] dt: bindings: i2c-mux-pca954x: add mux-locked property

[Bastian Stender <bst@pengutronix.de>]

Signed-off-by: Bastian Stender <bst@pengutronix.de>
---
 .../devicetree/bindings/i2c/i2c-mux-pca954x.txt  | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
index 34d91501342e..864ac91f8c1c 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
@@ -36,6 +36,22 @@ Optional Properties:
     - first cell is the pin number
     - second cell is used to specify flags.
     See also Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+  - mux-locked: If present, explicitly allow unrelated I2C transactions on the
+    parent I2C adapter at these times:
+    + during setup of the multiplexer
+    + between setup of the multiplexer and the child bus I2C transaction
+    + between the child bus I2C transaction and releasing of the multiplexer
+    + during releasing of the multiplexer
+
+    However, I2C transactions to devices behind all I2C multiplexers connected
+    to the same parent adapter that this multiplexer is connected to are blocked
+    for the full duration of the complete multiplexed I2C transaction (i.e.
+    including the times covered by the above list).
+    If mux-locked is not present, the multiplexer is assumed to be parent-locked.
+    This means that no unrelated I2C transactions are allowed on the parent I2C
+    adapter for the complete multiplexed I2C transaction.
+    The properties of mux-locked and parent-locked multiplexers are discussed
+    in more detail in Documentation/i2c/i2c-topology.
 
 Example:
 
-- 
2.17.0