nordic,nrf-pinctrl

Vendor: Nordic Semiconductor

Description

The nRF pin controller is a singleton node responsible for controlling
pin function selection and pin properties. For example, you can use this
node to route UART0 RX to pin P0.1 and enable the pull-up resistor on the
pin.

The node has the 'pinctrl' node label set in your SoC's devicetree,
so you can modify it like this:

  &pinctrl {
          /* your modifications go here */
  };

All device pin configurations should be placed in child nodes of the
'pinctrl' node, as shown in this example:

  /* You can put this in places like a board-pinctrl.dtsi file in
   * your board directory, or a devicetree overlay in your application.
   */
  &pinctrl {
    /* configuration for uart0 device, default state */
    uart0_default: uart0_default {
      /* group 1 ('group1' name is arbitrary) */
      group1 {
        /* configure P0.1 as UART_TX and P0.2 as UART_RTS */
        psels = <NRF_PSEL(UART_TX, 0, 1)>, <NRF_PSEL(UART_RTS, 0, 2)>;
      };
      /* group 2 */
      group2 {
        /* configure P0.3 as UART_RX and P0.4 as UART_CTS */
        psels = <NRF_PSEL(UART_RX, 0, 3)>, <NRF_PSEL(UART_CTS, 0, 4)>;
        /* both P0.3 and P0.4 are configured with pull-up */
        bias-pull-up;
      };
    };
  };

The 'uart0_default' child node encodes the pin configurations for a
particular state of a device; in this case, the default (that is, active)
state. You would specify the low-power configuration for the same device
in a separate child node.

As shown, pin configurations are organized in groups within each child node.
Each group can specify a list of pin function selections in the 'psels'
property. The NRF_PSEL macro is used to specify a pin function selection.
If a pin needs to be explicitly disconnected, there is also the
NRF_PSEL_DISCONNECTED macro.
Available pin functions can be found in the
include/zephyr/dt-bindings/pinctrl/nrf-pinctrl.h header file.

A group can also specify shared pin properties common to all the specified
pins, such as the 'bias-pull-up' property in group 2. Here is a list of
supported standard pin properties:

- bias-disable: Disable pull-up/down (default behavior, not required).
- bias-pull-up: Enable pull-up resistor.
- bias-pull-down: Enable pull-down resistor.
- low-power-enable: Configure pin as an input with input buffer
  disconnected.

Note that bias options are mutually exclusive.

To link this pin configuration with a device, use a pinctrl-N property
for some number N, like this example you could place in your board's DTS
file:

   #include "board-pinctrl.dtsi"

   &uart0 {
         pinctrl-0 = <&uart0_default>;
         pinctrl-names = "default";
   };

Properties

Top level properties

These property descriptions apply to “nordic,nrf-pinctrl” nodes themselves. This page also describes child node properties in the following sections.

Node specific properties

Properties not inherited from the base binding file.

(None)

Deprecated node specific properties

Deprecated properties not inherited from the base binding file.

(None)

Base properties

Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “nordic,nrf-pinctrl” compatible.

Name

Type

Details

status

string

indicates the operational status of a device

Legal values: 'ok', 'okay', 'disabled', 'reserved', 'fail', 'fail-sss'

See Important properties for more information.

compatible

string-array

compatible strings

This property is required.

See Important properties for more information.

reg

array

register space

See Important properties for more information.

reg-names

string-array

name of each register space

interrupts

array

interrupts for device

See Important properties for more information.

interrupts-extended

compound

extended interrupt specifier for device

interrupt-names

string-array

name of each interrupt

interrupt-parent

phandle

phandle to interrupt controller node

label

string

Human readable string describing the device (used as device_get_binding() argument)

See Important properties for more information.

This property is deprecated.

clocks

phandle-array

Clock gate information

clock-names

string-array

name of each clock

#address-cells

int

number of address cells in reg property

#size-cells

int

number of size cells in reg property

dmas

phandle-array

DMA channels specifiers

dma-names

string-array

Provided names of DMA channel specifiers

io-channels

phandle-array

IO channels specifiers

io-channel-names

string-array

Provided names of IO channel specifiers

mboxes

phandle-array

mailbox / IPM channels specifiers

mbox-names

string-array

Provided names of mailbox / IPM channel specifiers

power-domains

phandle-array

Power domain specifiers

power-domain-names

string-array

Provided names of power domain specifiers

#power-domain-cells

int

Number of cells in power-domains property

zephyr,deferred-init

boolean

Do not initialize device automatically on boot. Device should be manually
initialized using device_init().

wakeup-source

boolean

Property to identify that a device can be used as wake up source.

When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.

Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.

zephyr,pm-device-runtime-auto

boolean

Automatically configure the device for runtime power management after the
init function runs.

zephyr,disabling-power-states

phandles

List of power states that will disable this device power.

Grandchild node properties

Name

Type

Details

psels

array

An array of pins sharing the same group properties. The pins should
be defined using the NRF_PSEL utility macro that encodes the port,
pin and function. NRF_PSEL_DISCONNECTED is also available to explicitly
disconnect a pin.

This property is required.

nordic,drive-mode

int

Pin output drive mode. Available drive modes are pre-defined in
nrf-pinctrl.h. Note that extra modes may not be available on certain
devices. Defaults to standard mode for 0 and 1 (NRF_DRIVE_S0S1), the
SoC default, except for the "nordic,nrf-twi" and "nordic,nrf-twim"
nodes where NRF_DRIVE_S0S1 is always overridden with NRF_DRIVE_S0D1
(standard '0', disconnect '1').

nordic,invert

boolean

Invert pin polarity (set the active state to low).
Only valid for PWM channel output pins.

bias-disable

boolean

disable any pin bias

bias-pull-up

boolean

enable pull-up resistor

bias-pull-down

boolean

enable pull-down resistor

low-power-enable

boolean

enable low power mode