ambiq,apollo3-pinctrl

Vendor: Ambiq Micro, Inc.

Description

The Ambiq Apollo3 pin controller is a node responsible for controlling
pin function selection and pin properties, such as routing a UART0 TX
to pin 60 and enabling the pullup resistor on that 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.
*/

/* include pre-defined combinations for the SoC variant used by the board */
#include <dt-bindings/pinctrl/ambiq-apollo3-pinctrl.h>

&pinctrl {
  uart0_default: uart0_default {
    group1 {
      pinmux = <UART0TX_P60>;
    };
    group2 {
      pinmux = <UART0RX_P47>;
      input-enable;
    };
  };
};

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.

As shown, pin configurations are organized in groups within each child node.
Each group can specify a list of pin function selections in the 'pinmux'
property.

A group can also specify shared pin properties common to all the specified
pins, such as the 'input-enable' property in group 2.

Properties

Top level properties

These property descriptions apply to “ambiq,apollo3-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 “ambiq,apollo3-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

pinmux

array

An array of pins sharing the same group properties. Each
element of the array is an integer constructed from the
pin number and the alternative function of the pin.

This property is required.

drive-strength

string

The drive strength of a pin, relative to full-driver strength.
The default value is 0.1, which is the reset value of resigers
PADREGx.PADnSTRNG and ALTPADCFGx.PADn_DS1.

Default value: 0.1

Legal values: '0.1', '0.5', '0.75', '1.0'

ambiq,pull-up-ohms

int

The 1.5K-24K pullup values are valid for select I2C enabled pads.
For Apollo3 these pins are 0-1,5-6,8-9,25,27,39-40,42-43,48-49.
The default value is 1500 ohms, which is the reset value of
register PADREGx.PADxRSEL.

Default value: 1500

Legal values: 1500, 6000, 12000, 24000

ambiq,iom-nce-module

int

IOM nCE module select, selects the SPI channel (CE) number (0-3).
The default value is 0, which is the reset value of
register CFGx.GPIOnOUTCFG. If the pin is not a CE, this
descriptor will be ignored.

ambiq,iom-mspi

int

Indicates the module which uses specific CE pin, 1 if CE is IOM, 0 if MSPI.
User should check g_ui8NCEtable in am_hal_gpio.c for the mapping
information and config the pins accordingly, we give a default value
0 here to make it be consistent with AM_HAL_GPIO_PINCFG_DEFAULT in
ambiq hal. If the pin is not a CE, this descriptor will be ignored.

ambiq,iom-num

int

Indicates the instance which uses specific CE pin.
IOM number (0-5) or MSPI (0-2).
User should check g_ui8NCEtable in am_hal_gpio.c for the mapping
information and config the pins accordingly, we give a default value
0 here to make it be consistent with AM_HAL_GPIO_PINCFG_DEFAULT in
ambiq hal. If the pin is not a CE, this descriptor will be ignored.

bias-high-impedance

boolean

high impedance mode ("third-state", "floating")

bias-pull-up

boolean

enable pull-up resistor

bias-pull-down

boolean

enable pull-down resistor

drive-push-pull

boolean

drive actively high and low

drive-open-drain

boolean

drive with open drain (hardware AND)

input-enable

boolean

enable input on pin (e.g. enable an input buffer, no effect on output)