nxp,s32-gpio

Vendor: NXP Semiconductors

Description

NXP S32 GPIO controller.

The GPIO controller provides the option to route external input pad interrupts
to either the SIUL2 EIRQ interrupt controller or, when available on the SoC,
the WKPU interrupt controller. By default, GPIO interrupts are routed to the
SIUL2 EIRQ interrupt controller.

To route external interrupts to the WKPU interrupt controller, the GPIO
specifier must be supplied with the flag `NXP_S32_GPIO_INT_WKPU`. For example,
the following snippet of devicetree source code instructs the GPIO controller
to route the interrupt from pin 9 of `gpioa` to the WKPU interrupt controller:

  #include <zephyr/dt-bindings/gpio/nxp-s32-gpio.h>

  &device {
      gpios = <&gpioa 9 (NXP_S32_GPIO_INT_WKPU | GPIO_ACTIVE_HIGH)>;
  };

Explicitly specifying the routing of a GPIO interrupt to a particular
interrupt controller allows for the allocation of distinct interrupt
priorities according to application-specific requirements. This is owing to
the fact that each interrupt controller features its own interrupt vector.
To illustrate, it is plausible to allocate the board's button interrupts to
the interrupt controller configured with a lower priority compared to the one
designated for the data-ready interrupt originating from a sensor. This
decision is justified by the potentially higher importance of the latter
interrupt to the overall system operation.

The `NXP_S32_GPIO_INT_WKPU` flag is intended exclusively for specifying WKPU
as the interrupt controller for the corresponding GPIO. It's worth noting that
despite being named WKPU, the flag is not meant to configure GPIOs as wake-up
sources.

Properties

Top level properties

These property descriptions apply to “nxp,s32-gpio” nodes themselves. This page also describes child node properties in the following sections.

Properties not inherited from the base binding file.

Name

Type

Details

nxp,wkpu

phandle

NXP WKPU controller associated to this GPIO port.

nxp,wkpu-interrupts

array

Map between WKPU external interrupt sources and pins of this GPIO port,
as in a tuple `<gpio-pin wkpu-interrupt-source>`.

#gpio-cells

int

Number of items to expect in a GPIO specifier

This property is required.

Constant value: 2

gpio-controller

boolean

Convey's this node is a GPIO controller

This property is required.

ngpios

int

This property indicates the number of in-use slots of available slots
for GPIOs. The typical example is something like this: the hardware
register is 32 bits wide, but only 18 of the bits have a physical
counterpart. The driver is generally written so that all 32 bits can
be used, but the IP block is reused in a lot of designs, some using
all 32 bits, some using 18 and some using 12. In this case, setting
"ngpios = <18>;" informs the driver that only the first 18 GPIOs, at
local offset 0 .. 17, are in use.  For cases in which there might be
holes in the slot range, this value should be the max slot number+1.

Default value: 32

gpio-reserved-ranges

array

If not all the GPIOs at offsets 0...N-1 are usable for ngpios = <N>, then
this property contains an additional set of tuples which specify which GPIOs
are unusable. This property indicates the start and size of the GPIOs
that can't be used.

For example, setting "gpio-reserved-ranges = <3 2>, <10 1>;" means that
GPIO offsets 3, 4, and 10 are not usable, even if ngpios = <18>.

gpio-line-names

string-array

This is an array of strings defining the names of the GPIO lines
going out of the GPIO controller

Child node properties

Name

Type

Details

gpio-hog

boolean

Conveys this node is a GPIO hog.

This property is required.

gpios

array

This is an array of GPIO specifiers (e.g. pin, flags) to be hogged. The number of array
entries must be an integer multiple of the number of GPIO specifier cells for the parent
GPIO controller.

This property is required.

input

boolean

If this property is set, the GPIO is configured as an input. This property takes
precedence over the output-low and output-high properties.

output-low

boolean

If this property is set, the GPIO is configured as an output set to logical low. This
property takes precedence over the output-high property.

output-high

boolean

If this property is set, the GPIO is configured as an output set to logical high.

line-name

string

Optional GPIO line name.

Specifier cell names

  • gpio cells: pin, flags