# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/i2c/i2c-demux-pinctrl.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Pinctrl-based I2C Bus Demultiplexer
maintainers:
- Wolfram Sang <[email protected]>
description: |
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|--/ |
| +------------+ |
| |
+-------------------------------+
allOf:
- $ref: /schemas/i2c/i2c-controller.yaml#
properties:
compatible:
const: i2c-demux-pinctrl
i2c-parent:
$ref: /schemas/types.yaml#/definitions/phandle-array
items:
maxItems: 1
description:
List of phandles of I2C masters available for selection. The first one
will be used as default.
i2c-bus-name:
$ref: /schemas/types.yaml#/definitions/string
description:
The name of this bus. Also needed as pinctrl-name for the I2C parents.
required:
- compatible
- i2c-parent
- i2c-bus-name
unevaluatedProperties: false
examples:
- |
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>
gpioi2c2: i2c-9 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "i2c-gpio";
scl-gpios = <&gpio5 5 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
sda-gpios = <&gpio5 6 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
i2c-gpio,delay-us = <5>;
// The I2C controller must have its status "disabled". The I2C bus
// demultiplexer will enable it at runtime when needed.
status = "disabled";
};
iic2: i2c@e6520000 {
reg = <0xe6520000 0x425>;
pinctrl-0 = <&iic2_pins>;
// The pinctrl property for the parent I2C controller needs a pinctrl
// state with the same name as i2c-bus-name in the I2C bus demultiplexer
// node, not "default"!
pinctrl-names = "i2c-hdmi";
clock-frequency = <100000>;
// The I2C controller must have its status "disabled". The I2C bus
// demultiplexer will enable it at runtime when needed.
status = "disabled";
};
i2c2: i2c@e6530000 {
reg = <0 0xe6530000 0 0x40>;
pinctrl-0 = <&i2c2_pins>;
// The pinctrl property for the parent I2C controller needs a pinctrl
// state with the same name as i2c-bus-name in the I2C bus demultiplexer
// node, not "default"!
pinctrl-names = "i2c-hdmi";
clock-frequency = <100000>;
// The I2C controller must have its status "disabled". The I2C bus
// demultiplexer will enable it at runtime when needed.
status = "disabled";
};
// Example for a bus to be demuxed. It contains various I2C clients for
// HDMI, so the bus is named "i2c-hdmi":
i2chdmi: i2c-mux3 {
compatible = "i2c-demux-pinctrl";
i2c-parent = <&iic2>, <&i2c2>, <&gpioi2c2>;
i2c-bus-name = "i2c-hdmi";
#address-cells = <1>;
#size-cells = <0>;
ak4643: codec@12 {
compatible = "asahi-kasei,ak4643";
#sound-dai-cells = <0>;
reg = <0x12>;
};
composite-in@20 {
compatible = "adi,adv7180";
reg = <0x20>;
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>;
clocks = <&cec_clock>;
clock-names = "cec";
avdd-supply = <&fixedregulator1v8>;
dvdd-supply = <&fixedregulator1v8>;
pvdd-supply = <&fixedregulator1v8>;
dvdd-3v-supply = <&fixedregulator3v3>;
bgvdd-supply = <&fixedregulator1v8>;
adi,input-depth = <8>;
adi,input-colorspace = "rgb";
adi,input-clock = "1x";
ports {
#address-cells = <1>;
#size-cells = <0>;
port@0 {
reg = <0>;
adv7511_in: endpoint {
remote-endpoint = <&lvds0_out>;
};
};
port@1 {
reg = <1>;
adv7511_out: endpoint {
remote-endpoint = <&hdmi_con_out>;
};
};
};
};
};
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