linux/Documentation/devicetree/bindings/pinctrl/pinctrl-stmfx.txt
Amelie Delaunay 2e0b80ce45 dt-bindings: pinctrl: document the STMFX pinctrl bindings
This patch adds documentation of device tree bindings for the
STMicroelectronics Multi-Function eXpander (STMFX) GPIO expander.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2019-05-10 08:21:27 +01:00

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STMicroelectronics Multi-Function eXpander (STMFX) GPIO expander bindings
ST Multi-Function eXpander (STMFX) offers up to 24 GPIOs expansion.
Please refer to ../mfd/stmfx.txt for STMFX Core bindings.
Required properties:
- compatible: should be "st,stmfx-0300-pinctrl".
- #gpio-cells: should be <2>, the first cell is the GPIO number and the second
cell is the gpio flags in accordance with <dt-bindings/gpio/gpio.h>.
- gpio-controller: marks the device as a GPIO controller.
- #interrupt-cells: should be <2>, the first cell is the GPIO number and the
second cell is the interrupt flags in accordance with
<dt-bindings/interrupt-controller/irq.h>.
- interrupt-controller: marks the device as an interrupt controller.
- gpio-ranges: specifies the mapping between gpio controller and pin
controller pins. Check "Concerning gpio-ranges property" below.
Please refer to ../gpio/gpio.txt.
Please refer to pinctrl-bindings.txt for pin configuration.
Required properties for pin configuration sub-nodes:
- pins: list of pins to which the configuration applies.
Optional properties for pin configuration sub-nodes (pinconf-generic ones):
- bias-disable: disable any bias on the pin.
- bias-pull-up: the pin will be pulled up.
- bias-pull-pin-default: use the pin-default pull state.
- bias-pull-down: the pin will be pulled down.
- drive-open-drain: the pin will be driven with open drain.
- drive-push-pull: the pin will be driven actively high and low.
- output-high: the pin will be configured as an output driving high level.
- output-low: the pin will be configured as an output driving low level.
Note that STMFX pins[15:0] are called "gpio[15:0]", and STMFX pins[23:16] are
called "agpio[7:0]". Example, to refer to pin 18 of STMFX, use "agpio2".
Concerning gpio-ranges property:
- if all STMFX pins[24:0] are available (no other STMFX function in use), you
should use gpio-ranges = <&stmfx_pinctrl 0 0 24>;
- if agpio[3:0] are not available (STMFX Touchscreen function in use), you
should use gpio-ranges = <&stmfx_pinctrl 0 0 16>, <&stmfx_pinctrl 20 20 4>;
- if agpio[7:4] are not available (STMFX IDD function in use), you
should use gpio-ranges = <&stmfx_pinctrl 0 0 20>;
Example:
stmfx: stmfx@42 {
...
stmfx_pinctrl: stmfx-pin-controller {
compatible = "st,stmfx-0300-pinctrl";
#gpio-cells = <2>;
#interrupt-cells = <2>;
gpio-controller;
interrupt-controller;
gpio-ranges = <&stmfx_pinctrl 0 0 24>;
joystick_pins: joystick {
pins = "gpio0", "gpio1", "gpio2", "gpio3", "gpio4";
drive-push-pull;
bias-pull-up;
};
};
};
Example of STMFX GPIO consumers:
joystick {
compatible = "gpio-keys";
#address-cells = <1>;
#size-cells = <0>;
pinctrl-0 = <&joystick_pins>;
pinctrl-names = "default";
button-0 {
label = "JoySel";
linux,code = <KEY_ENTER>;
interrupt-parent = <&stmfx_pinctrl>;
interrupts = <0 IRQ_TYPE_EDGE_RISING>;
};
button-1 {
label = "JoyDown";
linux,code = <KEY_DOWN>;
interrupt-parent = <&stmfx_pinctrl>;
interrupts = <1 IRQ_TYPE_EDGE_RISING>;
};
button-2 {
label = "JoyLeft";
linux,code = <KEY_LEFT>;
interrupt-parent = <&stmfx_pinctrl>;
interrupts = <2 IRQ_TYPE_EDGE_RISING>;
};
button-3 {
label = "JoyRight";
linux,code = <KEY_RIGHT>;
interrupt-parent = <&stmfx_pinctrl>;
interrupts = <3 IRQ_TYPE_EDGE_RISING>;
};
button-4 {
label = "JoyUp";
linux,code = <KEY_UP>;
interrupt-parent = <&stmfx_pinctrl>;
interrupts = <4 IRQ_TYPE_EDGE_RISING>;
};
};
leds {
compatible = "gpio-leds";
orange {
gpios = <&stmfx_pinctrl 17 1>;
};
blue {
gpios = <&stmfx_pinctrl 19 1>;
};
}