bindings/i2c/i2c-demux-pinctrl.yaml

   1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 %YAML 1.2
   3 ---
   4 $id: http://devicetree.org/schemas/i2c/i2c-demux-pinctrl.yaml#
   5 $schema: http://devicetree.org/meta-schemas/core.yaml#
   6
   7 title: Pinctrl-based I2C Bus Demultiplexer
   8
   9 maintainers:
  10   - Wolfram Sang <wsa+renesas@sang-engineering.com>
  11
  12 description: |
  13   This binding describes an I2C bus demultiplexer that uses pin multiplexing to
  14   route the I2C signals, and represents the pin multiplexing configuration
  15   using the pinctrl device tree bindings.  This may be used to select one I2C
  16   IP core at runtime which may have a better feature set for a given task than
  17   another I2C IP core on the SoC.  The most simple example is to fall back to
  18   GPIO bitbanging if your current runtime configuration hits an errata of the
  19   internal IP core.
  20
  21       +-------------------------------+
  22       | SoC                           |
  23       |                               |   +-----+  +-----+
  24       |   +------------+              |   | dev |  | dev |
  25       |   |I2C IP Core1|--\           |   +-----+  +-----+
  26       |   +------------+   \-------+  |      |        |
  27       |                    |Pinctrl|--|------+--------+
  28       |   +------------+   +-------+  |
  29       |   |I2C IP Core2|--/           |
  30       |   +------------+              |
  31       |                               |
  32       +-------------------------------+
  33
  34 allOf:
  35   - $ref: i2c-mux.yaml
  36   - $ref: /schemas/i2c/i2c-controller.yaml#
  37
  38 properties:
  39   compatible:
  40     const: i2c-demux-pinctrl
  41
  42   i2c-parent:
  43     $ref: /schemas/types.yaml#/definitions/phandle-array
  44     description:
  45       List of phandles of I2C masters available for selection.  The first one
  46       will be used as default.
  47
  48   i2c-bus-name:
  49     $ref: /schemas/types.yaml#/definitions/string
  50     description:
  51       The name of this bus.  Also needed as pinctrl-name for the I2C parents.
  52
  53 required:
  54   - compatible
  55   - i2c-parent
  56   - i2c-bus-name
  57
  58 unevaluatedProperties: false
  59
  60 examples:
  61   - |
  62     #include <dt-bindings/gpio/gpio.h>
  63     #include <dt-bindings/interrupt-controller/irq.h>
  64
  65     gpioi2c2: i2c-9 {
  66         #address-cells = <1>;
  67         #size-cells = <0>;
  68         compatible = "i2c-gpio";
  69         scl-gpios = <&gpio5 5 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
  70         sda-gpios = <&gpio5 6 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>;
  71         i2c-gpio,delay-us = <5>;
  72
  73         // The I2C controller must have its status "disabled".  The I2C bus
  74         // demultiplexer will enable it at runtime when needed.
  75         status = "disabled";
  76     };
  77
  78     iic2: i2c@e6520000 {
  79         reg = <0xe6520000 0x425>;
  80         pinctrl-0 = <&iic2_pins>;
  81         // The pinctrl property for the parent I2C controller needs a pinctrl
  82         // state with the same name as i2c-bus-name in the I2C bus demultiplexer
  83         // node, not "default"!
  84         pinctrl-names = "i2c-hdmi";
  85
  86         clock-frequency = <100000>;
  87
  88         // The I2C controller must have its status "disabled".  The I2C bus
  89         // demultiplexer will enable it at runtime when needed.
  90         status = "disabled";
  91     };
  92
  93     i2c2: i2c@e6530000 {
  94         reg = <0 0xe6530000 0 0x40>;
  95         pinctrl-0 = <&i2c2_pins>;
  96         // The pinctrl property for the parent I2C controller needs a pinctrl
  97         // state with the same name as i2c-bus-name in the I2C bus demultiplexer
  98         // node, not "default"!
  99         pinctrl-names = "i2c-hdmi";
 100
 101         clock-frequency = <100000>;
 102
 103         // The I2C controller must have its status "disabled".  The I2C bus
 104         // demultiplexer will enable it at runtime when needed.
 105         status = "disabled";
 106     };
 107
 108     // Example for a bus to be demuxed.  It contains various I2C clients for
 109     // HDMI, so the bus is named "i2c-hdmi":
 110     i2chdmi: i2c-mux3 {
 111             compatible = "i2c-demux-pinctrl";
 112             i2c-parent = <&iic2>, <&i2c2>, <&gpioi2c2>;
 113             i2c-bus-name = "i2c-hdmi";
 114             #address-cells = <1>;
 115             #size-cells = <0>;
 116
 117             ak4643: codec@12 {
 118                     compatible = "asahi-kasei,ak4643";
 119                     #sound-dai-cells = <0>;
 120                     reg = <0x12>;
 121             };
 122
 123             composite-in@20 {
 124                     compatible = "adi,adv7180";
 125                     reg = <0x20>;
 126
 127                     port {
 128                             adv7180: endpoint {
 129                                     bus-width = <8>;
 130                                     remote-endpoint = <&vin1ep0>;
 131                             };
 132                     };
 133             };
 134
 135             hdmi@39 {
 136                     compatible = "adi,adv7511w";
 137                     reg = <0x39>;
 138                     interrupt-parent = <&gpio1>;
 139                     interrupts = <15 IRQ_TYPE_LEVEL_LOW>;
 140                     clocks = <&cec_clock>;
 141                     clock-names = "cec";
 142
 143                     avdd-supply = <&fixedregulator1v8>;
 144                     dvdd-supply = <&fixedregulator1v8>;
 145                     pvdd-supply = <&fixedregulator1v8>;
 146                     dvdd-3v-supply = <&fixedregulator3v3>;
 147                     bgvdd-supply = <&fixedregulator1v8>;
 148
 149                     adi,input-depth = <8>;
 150                     adi,input-colorspace = "rgb";
 151                     adi,input-clock = "1x";
 152
 153                     ports {
 154                             #address-cells = <1>;
 155                             #size-cells = <0>;
 156
 157                             port@0 {
 158                                     reg = <0>;
 159                                     adv7511_in: endpoint {
 160                                             remote-endpoint = <&lvds0_out>;
 161                                     };
 162                             };
 163
 164                             port@1 {
 165                                     reg = <1>;
 166                                     adv7511_out: endpoint {
 167                                             remote-endpoint = <&hdmi_con_out>;
 168                                     };
 169                             };
 170                     };
 171             };
 172     };