[PATCH 3/7] dt-bindings: i2c: add support for 'i2c-gate' subnode

Peter Rosin
2016-07-27T08:44:21Z

Handle i2c gates similarly to how i2c arbitrators are handled.
This gets rid of a pointless 'reg' property for i2c gates.

I.e. this new and more compact style

some-gate {
i2c-gate {
#address-cells = <1>;
#size-cells = <0>;

some-i2c-device@50 {
reg = <0x50>;
};
};
};

instead of the old

some-gate {
#address-cells = <1>;
#size-cells = <0>;

i2c@0 {
reg = <0>;

#address-cells = <1>;
#size-cells = <0>;

some-i2c-device@50 {
reg = <0x50>;
};
};
};

Signed-off-by: Peter Rosin <peda@axentia.se>
---
Documentation/devicetree/bindings/i2c/i2c-gate.txt | 35 ++++++++++++++++++++++
MAINTAINERS | 1 +
2 files changed, 36 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-gate.txt

diff --git a/Documentation/devicetree/bindings/i2c/i2c-gate.txt b/Documentation/devicetree/bindings/i2c/i2c-gate.txt
new file mode 100644
index 000000000000..78f17892dfc6
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-gate.txt
@@ -0,0 +1,35 @@
+Common i2c gate properties.
+
+- i2c-gate child node
+
+Required properties for the i2c-gate child node:
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties for i2c-gate child node:
+- Child nodes conforming to i2c bus binding
+
+
+Example :
+
+ /*
+ An Invensense mpu9150 at address 0x68 featuring an on-chip Asahi
+ Kasei ak8975 compass behind a gate.
+ */
+
+ mpu9150@68 {
+ compatible = "invensense,mpu9150";
+ reg = <0x68>;
+ interrupt-parent = <&gpio1>;
+ interrupts = <18 1>;
+
+ i2c-gate {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ax8975@0c {
+ compatible = "ak,ak8975";
+ reg = <0x0c>;
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 543052305a09..0e6cc071c480 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5525,6 +5525,7 @@ F: Documentation/i2c/i2c-topology
F: Documentation/i2c/muxes/
F: Documentation/devicetree/bindings/i2c/i2c-mux*
F: Documentation/devicetree/bindings/i2c/i2c-arb*
+F: Documentation/devicetree/bindings/i2c/i2c-gate*
F: drivers/i2c/i2c-mux.c
F: drivers/i2c/muxes/
F: include/linux/i2c-mux.h
--
2.1.4