nordic,nrf-pinctrl

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.
Available pin functions can be found in the
include/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.

Properties not inherited from the base binding file.

(None)

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.
`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
`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.

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. This property is required.
`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.
`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