u-boot-brain/doc/README.gpio

43 lines
1.1 KiB
Plaintext

GPIO hog (CONFIG_GPIO_HOG)
--------
All the GPIO hog are initialized in gpio_hog_probe_all() function called in
board_r.c just before board_late_init() but you can also acces directly to
the gpio with gpio_hog_lookup_name().
Example, for the device tree:
tca6416@20 {
compatible = "ti,tca6416";
reg = <0x20>;
#gpio-cells = <2>;
gpio-controller;
env_reset {
gpio-hog;
input;
gpios = <6 GPIO_ACTIVE_LOW>;
};
boot_rescue {
gpio-hog;
input;
line-name = "foo-bar-gpio";
gpios = <7 GPIO_ACTIVE_LOW>;
};
};
You can than access the gpio in your board code with:
struct gpio_desc *desc;
int ret;
ret = gpio_hog_lookup_name("boot_rescue", &desc);
if (ret)
return;
if (dm_gpio_get_value(desc) == 1)
printf("\nBooting into Rescue System\n");
else if (dm_gpio_get_value(desc) == 0)
printf("\nBoot normal\n");