取得 Ethernet 是否有連線的function
/TRUNK/SDK4120/source/linux-2.6.36.x/drivers/net/raeth/raether.c

GPIO 定義
linux-2.6.36.x/drivers/char/ralink_gpio.c

GPIO 預設值
linux-2.6.36.x/drivers/char/ralink_gpio.c

void ralink_gpio_led_init_timer(void)
{
...
}