From d635711daa98be86d4c7fd01499c34f566b54ccb Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Fri, 10 Jun 2016 05:30:17 -0300
Subject: Linux-libre 4.6.2-gnu

---
 .../devicetree/bindings/i2c/i2c-demux-pinctrl.txt  | 135 +++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt

(limited to 'Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt')

diff --git a/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt b/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt
new file mode 100644
index 000000000..6078aefe7
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.txt
@@ -0,0 +1,135 @@
+Pinctrl-based I2C Bus DeMux
+
+This binding describes an I2C bus demultiplexer that uses pin multiplexing to
+route the I2C signals, and represents the pin multiplexing configuration using
+the pinctrl device tree bindings. This may be used to select one I2C IP core at
+runtime which may have a better feature set for a given task than another I2C
+IP core on the SoC. The most simple example is to fall back to GPIO bitbanging
+if your current runtime configuration hits an errata of the internal IP core.
+
+    +-------------------------------+
+    | SoC                           |
+    |                               |   +-----+  +-----+
+    |   +------------+              |   | dev |  | dev |
+    |   |I2C IP Core1|--\           |   +-----+  +-----+
+    |   +------------+   \-------+  |      |        |
+    |                    |Pinctrl|--|------+--------+
+    |   +------------+   +-------+  |
+    |   |I2C IP Core2|--/           |
+    |   +------------+              |
+    |                               |
+    +-------------------------------+
+
+Required properties:
+- compatible: "i2c-demux-pinctrl"
+- i2c-parent: List of phandles of I2C masters available for selection. The first
+	      one will be used as default.
+- i2c-bus-name: The name of this bus. Also needed as pinctrl-name for the I2C
+		parents.
+
+Furthermore, I2C mux properties and child nodes. See mux.txt in this directory.
+
+Example:
+
+Here is a snipplet for a bus to be demuxed. It contains various i2c clients for
+HDMI, so the bus is named "i2c-hdmi":
+
+	i2chdmi: i2c@8 {
+
+		compatible = "i2c-demux-pinctrl";
+		i2c-parent = <&gpioi2c>, <&iic2>, <&i2c2>;
+		i2c-bus-name = "i2c-hdmi";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ak4643: sound-codec@12 {
+			compatible = "asahi-kasei,ak4643";
+
+			#sound-dai-cells = <0>;
+			reg = <0x12>;
+		};
+
+		composite-in@20 {
+			compatible = "adi,adv7180";
+			reg = <0x20>;
+			remote = <&vin1>;
+
+			port {
+				adv7180: endpoint {
+					bus-width = <8>;
+					remote-endpoint = <&vin1ep0>;
+				};
+			};
+		};
+
+		hdmi@39 {
+			compatible = "adi,adv7511w";
+			reg = <0x39>;
+			interrupt-parent = <&gpio1>;
+			interrupts = <15 IRQ_TYPE_LEVEL_LOW>;
+
+			adi,input-depth = <8>;
+			adi,input-colorspace = "rgb";
+			adi,input-clock = "1x";
+			adi,input-style = <1>;
+			adi,input-justification = "evenly";
+
+			ports {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				port@0 {
+					reg = <0>;
+					adv7511_in: endpoint {
+						remote-endpoint = <&du_out_lvds0>;
+					};
+				};
+
+				port@1 {
+					reg = <1>;
+					adv7511_out: endpoint {
+						remote-endpoint = <&hdmi_con>;
+					};
+				};
+			};
+		};
+	};
+
+And for clarification, here are the snipplets for the i2c-parents:
+
+	gpioi2c: i2c@9 {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		compatible = "i2c-gpio";
+		status = "disabled";
+		gpios = <&gpio5 6 GPIO_ACTIVE_HIGH /* sda */
+			 &gpio5 5 GPIO_ACTIVE_HIGH /* scl */
+			>;
+		i2c-gpio,delay-us = <5>;
+	};
+
+...
+
+&i2c2	{
+	pinctrl-0 = <&i2c2_pins>;
+	pinctrl-names = "i2c-hdmi";
+
+	clock-frequency = <100000>;
+};
+
+...
+
+&iic2	{
+	pinctrl-0 = <&iic2_pins>;
+	pinctrl-names = "i2c-hdmi";
+
+	clock-frequency = <100000>;
+};
+
+Please note:
+
+- pinctrl properties for the parent I2C controllers need a pinctrl state
+  with the same name as i2c-bus-name, not "default"!
+
+- the i2c masters must have their status "disabled". This driver will
+  enable them at runtime when needed.
-- 
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