arch/arm/boot/dts/overlays/i2c-gpio-overlay.dts

   1 // Overlay for i2c_gpio bitbanging host bus.
   2 /dts-v1/;
   3 /plugin/;
   4
   5 #include <dt-bindings/gpio/gpio.h>
   6
   7 / {
   8         compatible = "brcm,bcm2835";
   9
  10         fragment@0 {
  11                 target-path = "/";
  12
  13                 __overlay__ {
  14                         i2c_gpio: i2c@0 {
  15                                 reg = <0xffffffff>;
  16                                 compatible = "i2c-gpio";
  17                                 gpios = <&gpio 23 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN) /* sda */
  18                                          &gpio 24 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN) /* scl */
  19                                         >;
  20                                 i2c-gpio,delay-us = <2>;        /* ~100 kHz */
  21                                 #address-cells = <1>;
  22                                 #size-cells = <0>;
  23                         };
  24                 };
  25         };
  26
  27         fragment@1 {
  28                 target-path = "/aliases";
  29                 __overlay__ {
  30                         i2c_gpio = "/i2c@0";
  31                 };
  32         };
  33
  34         fragment@2 {
  35                 target-path = "/__symbols__";
  36                 __overlay__ {
  37                         i2c_gpio = "/i2c@0";
  38                 };
  39         };
  40
  41         __overrides__ {
  42                 i2c_gpio_sda = <&i2c_gpio>,"gpios:4";
  43                 i2c_gpio_scl = <&i2c_gpio>,"gpios:16";
  44                 i2c_gpio_delay_us = <&i2c_gpio>,"i2c-gpio,delay-us:0";
  45                 bus = <&i2c_gpio>, "reg:0";
  46         };
  47 };