pinctrl: Document "function" + "pins" pinmux binding

Currently the "function" + "groups" combination is the only documented
format for pinmux nodes, although many drivers use "function" + "pins".
Update the generic pinctrl binding to include the "function" + "pins"
combination as well.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
index e9ebe5d35835..b73c96d24f59 100644
--- a/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
@@ -133,6 +133,9 @@ pin multiplexing nodes:
 
 function                - the mux function to select
 groups                  - the list of groups to select with this function
+                          (either this or "pins" must be specified)
+pins                    - the list of pins to select with this function (either
+                          this or "groups" must be specified)
 
 Example:
 
@@ -148,6 +151,10 @@ state_1_node_a {
                 groups = "spi0pins";
         };
 };
+state_2_node_a {
+        function = "i2c0";
+        pins = "mfio29", "mfio30";
+};
 
 == Generic pin configuration node content ==