# 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 = , 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.