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nxp,mcux-rt-pinctrl

Vendor: NXP Semiconductors

Description

The node has the 'pinctrl' node label set in MCUX RT SoC's devicetree. These
nodes can be autogenerated using the MCUXpresso config tools combined with
the rt_dts_gen.py script in NXP's HAL. The mux, mode, input, daisy, and cfg
fields in a group select the pins to be configured, and the remaining
devicetree properties set configuration values for those pins
for example, here is an group configuring LPUART1 pins:

group0 {
  pinmux = <&iomuxc_gpio_ad_b0_12_lpuart1_tx,
    &iomuxc_gpio_ad_b0_13_lpuart1_rx>;
  drive-strength = "r0-6";
  slew-rate = "slow";
  nxp,speed = "100-mhz";
};

This will select GPIO_AD_B0_12 as LPUART1 TX, and GPIO_AD_B0_13 as LPUART1 RX.
Both pins will be configured with a weak latch, drive strength of "r0-6",
slow slew rate, and 100 MHZ speed.
Note that the soc level iomuxc dts file can be examined to find the possible
pinmux options. Here are the affects of each property on the
IOMUXC SW_PAD_CTL register:
input-schmitt-enable: HYS=1
drive-open-drain: ODE=1
input-enable: SION=1 (in SW_MUX_CTL_PAD register)
bias-pull-down: PUE=1, PUS=<bias-pull-down-value>
bias-pull-up: PUE=1, PUS=<bias-pull-up-value>
bias-disable: PKE=0
slew-rate: SRE=<enum_idx>
drive-strength: DSE=<enum_idx>
nxp,speed: SPEED=<enum_idx>

If only required properties are supplied, the pin will have the following
configuration:
HYS=0,
ODE=0,
SION=0,
PUE=0,
PUS=0,
PKE=1,
SRE=<slew-rate>,
DSE=<drive-strength>,
SPEED=<nxp,speed>

Properties

Top level properties

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

Properties not inherited from the base binding file.

(None)

Grandchild node properties

Name

Type

Details

pinmux

phandles

Pin mux selections for this group. See the soc level iomuxc DTSI file
for a defined list of these options.

This property is required.

drive-strength

string

Pin output drive strength. Sets the DSE field in the IOMUXC peripheral.
the drive strength is expressed as a output impedance at a given voltage,
but maximum current values can be calculated from these impedances
for a specific load impedance.
000 DSE_0_output_driver_disabled_ — output driver disabled
001 DSE_1_R0_1 — 157 Ohm impedance @3.3V, 260 Ohm impedance @1.8V
010 DSE_2_R0_2 — 78 Ohm @3.3V, 130 Ohm @1.8V
011 DSE_3_R0_3 — 53 Ohm @3.3V, 88 Ohm @1.8V
100 DSE_4_R0_4 — 39 Ohm @3.3V, 65 Ohm @1.8V
101 DSE_5_R0_5 — 32 Ohm @3.3V, 52 Ohm @1.8V
110 DSE_6_R0_6 — 32 Ohm @3.3V, 43 Ohm @1.8V
111 DSE_7_R0_7 — 26 Ohm @3.3V, 37 Ohm @1.8V

This property is required.

Legal values: 'disabled', 'r0', 'r0-2', 'r0-3', 'r0-4', 'r0-5', 'r0-6', 'r0-7'

bias-pull-up-value

string

Select the value of the pull up resistor present on this pin
Corresponds to the PUS field in the IOMUXC peripheral.
47k resistor selected as default due to this being the default pullup
value on most SOC pins
00 Unused- no change will be applied to pin
01 PUS_1_47K_Ohm_Pull_Up — 47K Ohm Pull Up
10 PUS_2_100K_Ohm_Pull_Up — 100K Ohm Pull Up
11 PUS_2_22K_Ohm_Pull_Up — 22K Ohm Pull Up

Default value: 47k

Legal values: 'unused', '47k', '100k', '22k'

bias-pull-down-value

string

Select the value of the pull up resistor present on this pin
Corresponds to the PUS field in the IOMUXC peripheral. 100k is
currently the only supported pull down resistance.
00 PUS_0_100K_Ohm_Pull_Down - 100K Ohm Pull Down

Default value: 100k

Legal values: '100k'

slew-rate

string

Select slew rate for pin. Corresponds to SRE field in IOMUXC peripheral
0 SRE_0_Slow_Slew_Rate — Slow Slew Rate
1 SRE_1_Fast_Slew_Rate — Fast Slew Rate

This property is required.

Legal values: 'slow', 'fast'

nxp,speed

string

Sets pin speed. Corresponds to SPEED field in IOMUXC peripheral
00 SPEED_0_low_50MHz_ — low(50MHz)
01 SPEED_1_medium_100MHz_ — medium(100MHz)
10 SPEED_2_medium_150MHz_ — medium(150MHz)
11 SPEED_3_max_200MHz_ — max(200MHz)

Legal values: '50-mhz', '100-mhz', '150-mhz', '200-mhz'

bias-disable

boolean

disable any pin bias

bias-pull-up

boolean

enable pull-up resistor

bias-pull-down

boolean

enable pull-down resistor

drive-open-drain

boolean

drive with open drain (hardware AND)

input-enable

boolean

enable input on pin (no effect on output, such as enabling an input
buffer)

input-schmitt-enable

boolean

enable schmitt-trigger mode