80 lines · yaml
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)2%YAML 1.23---4$id: http://devicetree.org/schemas/gpio/gpio-delay.yaml#5$schema: http://devicetree.org/meta-schemas/core.yaml#6 7title: GPIO delay controller8 9maintainers:10 - Alexander Stein <linux@ew.tq-group.com>11 12description: |13 This binding describes an electrical setup where setting an GPIO output14 is delayed by some external setup, e.g. RC circuit.15 16 +----------+ +-----------+17 | | VCC_B | |18 | | | | |19 | | VCC_A _ | |20 | GPIO | | | R | Consumer |21 |controller| ___ |_| | |22 | | | | | | |23 | [IOx|-------| |--+-----|-----+ |24 | | |___| | | input |25 | | | | |26 +----------+ --- C +-----------+27 ---28 |29 -30 GND31 32 If the input on the consumer is controlled by an open-drain signal33 attached to an RC circuit the ramp-up delay is not under control34 of the GPIO controller.35 36properties:37 compatible:38 const: gpio-delay39 40 "#gpio-cells":41 description: |42 Specifies the pin, ramp-up and ramp-down delays. The43 delays are specified in microseconds.44 const: 345 46 gpios:47 description: Array of GPIOs which output signal change is delayed48 minItems: 149 maxItems: 3250 51 gpio-controller: true52 53 gpio-line-names:54 minItems: 155 maxItems: 3256 57required:58 - compatible59 - "#gpio-cells"60 - gpio-controller61 - gpios62 63additionalProperties: false64 65examples:66 - |67 #include <dt-bindings/gpio/gpio.h>68 69 enable_delay: enable-delay {70 compatible = "gpio-delay";71 #gpio-cells = <3>;72 gpio-controller;73 gpios = <&gpio0 3 GPIO_ACTIVE_LOW>,74 <&gpio3 1 GPIO_ACTIVE_HIGH>;75 };76 77 consumer {78 enable-gpios = <&enable_delay 0 130000 30000>;79 };80