| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| 2 | %YAML 1.2 |
| 3 | --- |
| 4 | $id: http://devicetree.org/schemas/gpio/gpio-delay.yaml# |
| 5 | $schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | |
| 7 | title: GPIO delay controller |
| 8 | |
| 9 | maintainers: |
| 10 | - Alexander Stein <linux@ew.tq-group.com> |
| 11 | |
| 12 | description: | |
| 13 | This binding describes an electrical setup where setting an GPIO output |
| 14 | 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 | GND |
| 31 | |
| 32 | If the input on the consumer is controlled by an open-drain signal |
| 33 | attached to an RC circuit the ramp-up delay is not under control |
| 34 | of the GPIO controller. |
| 35 | |
| 36 | properties: |
| 37 | compatible: |
| 38 | const: gpio-delay |
| 39 | |
| 40 | "#gpio-cells": |
| 41 | description: | |
| 42 | Specifies the pin, ramp-up and ramp-down delays. The |
| 43 | delays are specified in microseconds. |
| 44 | const: 3 |
| 45 | |
| 46 | gpios: |
| 47 | description: Array of GPIOs which output signal change is delayed |
| 48 | minItems: 1 |
| 49 | maxItems: 32 |
| 50 | |
| 51 | gpio-controller: true |
| 52 | |
| 53 | gpio-line-names: |
| 54 | minItems: 1 |
| 55 | maxItems: 32 |
| 56 | |
| 57 | required: |
| 58 | - compatible |
| 59 | - "#gpio-cells" |
| 60 | - gpio-controller |
| 61 | - gpios |
| 62 | |
| 63 | additionalProperties: false |
| 64 | |
| 65 | examples: |
| 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 | }; |