nxp,lpc-gpio

Vendor: NXP Semiconductors

Description

LPC GPIO node

Properties

Top level properties

These property descriptions apply to “nxp,lpc-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

gpio-controller

boolean

Convey's this node is a GPIO controller

This property is required.

#gpio-cells

int

Number of items to expect in a GPIO specifier

This property is required.

Constant value: 2

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

port

int

The GPIO port this node describes

This property is required.

Legal values: 0, 1, 2, 3, 4, 5, 6, 7

int-source

string

Interrupt source for the gpio port. For ports that can use the PINT
as an interrupt source for their pins (typically ports 0 and 1),
this can be set to PINT. Otherwise, the property should be set to "int-a"
or "int-b" if interrupt support is desired, and the appropriate IRQ number
should set for the device.

Default value: none

Legal values: 'pint', 'int-a', 'int-b', 'none'

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