1 files changed, 46 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-gpio.txt b/Documentation/devicetree/bindings/i2c/i2c-gpio.txt
new file mode 100644
index 000000000..38a05562d
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-gpio.txt
@@ -0,0 +1,46 @@
+Device-Tree bindings for i2c gpio driver
+
+Required properties:
+	- compatible = "i2c-gpio";
+	- sda-gpios: gpio used for the sda signal, this should be flagged as
+	  active high using open drain with (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)
+	  from <dt-bindings/gpio/gpio.h> since the signal is by definition
+	  open drain.
+	- scl-gpios: gpio used for the scl signal, this should be flagged as
+	  active high using open drain with (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)
+	  from <dt-bindings/gpio/gpio.h> since the signal is by definition
+	  open drain.
+
+Optional properties:
+	- i2c-gpio,scl-output-only: scl as output only
+	- i2c-gpio,delay-us: delay between GPIO operations (may depend on each platform)
+	- i2c-gpio,timeout-ms: timeout to get data
+
+Deprecated properties, do not use in new device tree sources:
+	- gpios: sda and scl gpio, alternative for {sda,scl}-gpios
+	- i2c-gpio,sda-open-drain: this means that something outside of our
+	  control has put the GPIO line used for SDA into open drain mode, and
+	  that something is not the GPIO chip. It is essentially an
+	  inconsistency flag.
+	- i2c-gpio,scl-open-drain: this means that something outside of our
+	  control has put the GPIO line used for SCL into open drain mode, and
+	  that something is not the GPIO chip. It is essentially an
+	  inconsistency flag.
+
+Example nodes:
+
+#include <dt-bindings/gpio/gpio.h>
+
+i2c@0 {
+	compatible = "i2c-gpio";
+	sda-gpios = <&pioA 23 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+	scl-gpios = <&pioA 24 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+	i2c-gpio,delay-us = <2>;	/* ~100 kHz */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	rv3029c2@56 {
+		compatible = "rv3029c2";
+		reg = <0x56>;
+	};
+};