HelenOS sources

AR9271_LED_PIN    245 uspace/drv/nic/ar9271/hw.c 	errno_t rc = hw_gpio_set_output(ar9271, AR9271_LED_PIN,
AR9271_LED_PIN    252 uspace/drv/nic/ar9271/hw.c 	rc = hw_gpio_set_value(ar9271, AR9271_LED_PIN, 0);
HelenOS homepage, sources at GitHub