u-boot/doc/device-tree-bindings/pinctrl/nexell,s5pxx18-pinctrl.txt

Binding for Nexell s5pxx18 pin cotroller
========================================

Nexell's ARM bases SoC's integrates a GPIO and Pin mux/config hardware
controller. It controls the input/output settings on the available pads/pins
and also provides ability to multiplex and configure the output of various
on-chip controllers onto these pads.

Please refer to pinctrl-bindings.txt in this directory for details of the
common pinctrl bindings used by client devices, including the meaning of the
phrase "pin configuration node".


Required properties:
  - compatible: "nexell,s5pxx18-pinctrl"
  - reg: should be register base and length as documented in the datasheet
  - interrupts: interrupt specifier for the controller over gpio and alive pins

Example:
pinctrl_0: pinctrl@c0010000 {
	compatible = "nexell,s5pxx18-pinctrl";
		reg = <0xc0010000 0xf000>;
		bootph-all;
};

Nexell's pin configuration nodes act as a container for an arbitrary number of
subnodes. Each of these subnodes represents some desired configuration for a
pin, a group, or a list of pins or groups. This configuration can include the
mux function to select on those pin(s)/group(s), and various pin configuration
parameters.

  Child nodes must be set at least one of the following settings:
  - pins = Select pins for using this function.
  - pin-function = Select the function for use in a selected pin.
  - pin-pull = Pull up/down configuration.
  - pin-strength = Drive strength configuration.

  Valid values for nexell,pins are:
     "gpioX-N" : X in {A,B,C,D,E}, N in {0-31}
  Valid values for nexell,pin-function are:
     "N"       : N in {0-3}.
                 This setting means that the value is different for each pin.
                 Please refer to datasheet.
  Valid values for nexell,pin-pull are:
     "N"       : 0 - Down, 1 - Up, 2 - Off
  Valid values for nexell,pin-strength are:
     "N"       : 0,1,2,3


Example:
  - pin settings
	mmc0_clk: mmc0-clk {
		pins = "gpioa-29";
		pin-function = <1>;
		pin-pull = <2>;
		pin-strength = <2>;
	};

	mmc0_cmd: mmc0-cmd {
		pins = "gpioa-31";
		pin-function = <1>;
		pin-pull = <2>;
		pin-strength = <1>;
	};

	mmc0_bus4: mmc0-bus-width4 {
		pins = "gpiob-1, gpiob-3, gpiob-5, gpiob-7";
		pin-function = <1>;
		pin-pull = <2>;
		pin-strength = <1>;
	};

  - used by client devices
	mmc0:mmc@... {
		pinctrl-names = "default";
		pinctrl-0 = <&mmc0_clk>, <&mmc0_cmd>, <&mmc0_bus4>;
		...
	};