doc/README.gpio

   1
   2 GPIO hog (CONFIG_GPIO_HOG)
   3 --------
   4
   5 All the GPIO hog are initialized using DM_FLAG_PROBE_AFTER_BIND DM flag
   6 after bind().
   7
   8 Example, for the device tree:
   9
  10         tca6416@20 {
  11                 compatible = "ti,tca6416";
  12                 reg = <0x20>;
  13                 #gpio-cells = <2>;
  14                 gpio-controller;
  15
  16                 env_reset {
  17                         gpio-hog;
  18                         input;
  19                         gpios = <6 GPIO_ACTIVE_LOW>;
  20                 };
  21                 boot_rescue {
  22                         gpio-hog;
  23                         input;
  24                         line-name = "foo-bar-gpio";
  25                         gpios = <7 GPIO_ACTIVE_LOW>;
  26                 };
  27         };
  28
  29 You can than access the gpio in your board code with:
  30
  31         struct gpio_desc *desc;
  32         int ret;
  33
  34         ret = gpio_hog_lookup_name("boot_rescue", &desc);
  35         if (ret)
  36                 return;
  37         if (dm_gpio_get_value(desc) == 1)
  38                 printf("\nBooting into Rescue System\n");
  39         else if (dm_gpio_get_value(desc) == 0)
  40                 printf("\nBoot normal\n");