dt-bindings: pinctrl: mcp23s08 update binding doc

The mcp23s08 driver moved to pinctrl recently. It accepts the
bias-pull-up pinctrl property since then. This updates the binding
doc to reflect that.

Thanks to Sebastian Reichel for the working example.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Lars Poeschel 2017-10-09 14:03:00 +02:00 committed by Linus Walleij
parent a157789b78
commit e8527b6eb6

View File

@ -81,3 +81,61 @@ gpiom1: gpio@0 {
reg = <0>;
spi-max-frequency = <1000000>;
};
Pull-up configuration
=====================
If pins are used as output, they can also be configured with pull-ups. This is
done with pinctrl.
Please refer file <devicetree/bindings/pinctrl/pinctrl-bindings.txt>
for details of the common pinctrl bindings used by client devices,
including the meaning of the phrase "pin configuration node".
Optional Pinmux properties:
--------------------------
Following properties are required if default setting of pins are required
at boot.
- pinctrl-names: A pinctrl state named per <pinctrl-binding.txt>.
- pinctrl[0...n]: Properties to contain the phandle for pinctrl states per
<pinctrl-binding.txt>.
The pin configurations are defined as child of the pinctrl states node. Each
sub-node have following properties:
Required properties:
------------------
- pins: List of pins. Valid values of pins properties are:
gpio0 ... gpio7 for the devices with 8 GPIO pins and
gpio0 ... gpio15 for the devices with 16 GPIO pins.
Optional properties:
-------------------
The following optional property is defined in the pinmux DT binding document
<pinctrl-bindings.txt>. Absence of this property will leave the configuration
in its default state.
bias-pull-up
Example with pinctrl to pull-up output pins:
gpio21: gpio@21 {
compatible = "microchip,mcp23017";
gpio-controller;
#gpio-cells = <0x2>;
reg = <0x21>;
interrupt-parent = <&socgpio>;
interrupts = <0x17 0x8>;
interrupt-names = "mcp23017@21 irq";
interrupt-controller;
#interrupt-cells = <0x2>;
microchip,irq-mirror;
pinctrl-names = "default";
pinctrl-0 = <&i2cgpio0irq &gpio21pullups>;
gpio21pullups: pinmux {
pins = "gpio0", "gpio1", "gpio2", "gpio3",
"gpio4", "gpio5", "gpio6", "gpio7",
"gpio8", "gpio9", "gpio10", "gpio11",
"gpio12", "gpio13", "gpio14", "gpio15";
bias-pull-up;
};
};