Using GPIO on BananaPro and Mainline

Hello together,

I'm trying to connect an LVDS panel to my BananPro and would like to switching power on/of and backlight on/off throw a GPIO pin.

So, first of all, I've added some lines to my DTS file (in &pio section).

This is for backlight driver (PH12 is connected to CON2 pin 7):

    bl_en_pins_a: bl_en@0 {
        allwinner,pins = "PH12";
        allwinner,function = "gpio_out";
        allwinner,drive = <SUN4I_PINCTRL_10_MA>;
        allwinner,pull = <SUN4I_PINCTRL_PULL_DOWN>;
    };

And this is for enable pin of voltage regulator (PH7 is connected to CON2 pin 6):

    lcd_power_pins_a: lcd_power@0 {
        allwinner,pins = "PH7";
        allwinner,function = "gpio_out";
        allwinner,drive = <SUN4I_PINCTRL_10_MA>;
        allwinner,pull = <SUN4I_PINCTRL_PULL_DOWN>;
    };

So, my question: How can I access those pins in linux (i.e. switch on or off and so one)?

I'm using mainline kernel 4.4.11 and BananaPRO.

Many thanks & kind regards,

Heinrich