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# Copyright (c) 2019, Linaro Limited
# SPDX-License-Identifier: Apache-2.0
# Common fields for GPIO controllers
properties:
"gpio-controller":
type: boolean
required: true
description: Convey's this node is a GPIO controller
"#gpio-cells":
type: int
required: true
description: Number of items to expect in a GPIO specifier
ngpios:
type: int
default: 32
description: |
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.
gpio-reserved-ranges:
type: array
description: |
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:
type: string-array
description: |
This is an array of strings defining the names of the GPIO lines
going out of the GPIO controller
child-binding:
description: |
Optional GPIO hog configuration.
Each GPIO controller may contain GPIO hog definitions. GPIO hogging is a mechanism for
providing automatic GPIO configuration during driver initialization when Kconfig
CONFIG_GPIO_HOGS is enabled.
Each GPIO hog is represented as a child node of the GPIO controller.
Example:
&gpio1 {
mux-hog {
gpio-hog;
gpios = <10 GPIO_ACTIVE_HIGH>, <11 GPIO_ACTIVE_HIGH>;
output-high;
};
};
&gpio2 {
test-hog {
gpio-hog;
gpios = <26 GPIO_ACTIVE_HIGH>;
output-low;
line-name = "test";
};
};
properties:
gpio-hog:
type: boolean
required: true
description: |
Conveys this node is a GPIO hog.
gpios:
type: array
required: true
description: |
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.
input:
type: boolean
description: |
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:
type: boolean
description: |
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:
type: boolean
description: |
If this property is set, the GPIO is configured as an output set to logical high.
line-name:
type: string
description: |
Optional GPIO line name.