1 # SPDX-License-Identifier: (GPL-2.0-only OR BS 1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2 2 %YAML 1.2
3 --- 3 ---
4 $id: http://devicetree.org/schemas/gpio/gpio-d 4 $id: http://devicetree.org/schemas/gpio/gpio-delay.yaml#
5 $schema: http://devicetree.org/meta-schemas/co 5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6 6
7 title: GPIO delay controller 7 title: GPIO delay controller
8 8
9 maintainers: 9 maintainers:
10 - Alexander Stein <linux@ew.tq-group.com> 10 - Alexander Stein <linux@ew.tq-group.com>
11 11
12 description: | 12 description: |
13 This binding describes an electrical setup w 13 This binding describes an electrical setup where setting an GPIO output
14 is delayed by some external setup, e.g. RC c 14 is delayed by some external setup, e.g. RC circuit.
15 15
16 +----------+ +----------- 16 +----------+ +-----------+
17 | | VCC_B | 17 | | VCC_B | |
18 | | | | 18 | | | | |
19 | | VCC_A _ | 19 | | VCC_A _ | |
20 | GPIO | | | R | Consumer 20 | GPIO | | | R | Consumer |
21 |controller| ___ |_| | 21 |controller| ___ |_| | |
22 | | | | | | 22 | | | | | | |
23 | [IOx|-------| |--+-----|-----+ 23 | [IOx|-------| |--+-----|-----+ |
24 | | |___| | | input 24 | | |___| | | input |
25 | | | | 25 | | | | |
26 +----------+ --- C +----------- 26 +----------+ --- C +-----------+
27 --- 27 ---
28 | 28 |
29 - 29 -
30 GND 30 GND
31 31
32 If the input on the consumer is controlled b 32 If the input on the consumer is controlled by an open-drain signal
33 attached to an RC circuit the ramp-up delay 33 attached to an RC circuit the ramp-up delay is not under control
34 of the GPIO controller. 34 of the GPIO controller.
35 35
36 properties: 36 properties:
37 compatible: 37 compatible:
38 const: gpio-delay 38 const: gpio-delay
39 39
40 "#gpio-cells": 40 "#gpio-cells":
41 description: | 41 description: |
42 Specifies the pin, ramp-up and ramp-down 42 Specifies the pin, ramp-up and ramp-down delays. The
43 delays are specified in microseconds. 43 delays are specified in microseconds.
44 const: 3 44 const: 3
45 45
46 gpios: 46 gpios:
47 description: Array of GPIOs which output s 47 description: Array of GPIOs which output signal change is delayed
48 minItems: 1 48 minItems: 1
49 maxItems: 32 49 maxItems: 32
50 50
51 gpio-controller: true 51 gpio-controller: true
52 52
53 gpio-line-names: 53 gpio-line-names:
54 minItems: 1 54 minItems: 1
55 maxItems: 32 55 maxItems: 32
56 56
57 required: 57 required:
58 - compatible 58 - compatible
59 - "#gpio-cells" 59 - "#gpio-cells"
60 - gpio-controller 60 - gpio-controller
61 - gpios 61 - gpios
62 62
63 additionalProperties: false 63 additionalProperties: false
64 64
65 examples: 65 examples:
66 - | 66 - |
67 #include <dt-bindings/gpio/gpio.h> 67 #include <dt-bindings/gpio/gpio.h>
68 68
69 enable_delay: enable-delay { 69 enable_delay: enable-delay {
70 compatible = "gpio-delay"; 70 compatible = "gpio-delay";
71 #gpio-cells = <3>; 71 #gpio-cells = <3>;
72 gpio-controller; 72 gpio-controller;
73 gpios = <&gpio0 3 GPIO_ACTIVE_LOW>, 73 gpios = <&gpio0 3 GPIO_ACTIVE_LOW>,
74 <&gpio3 1 GPIO_ACTIVE_HIGH>; 74 <&gpio3 1 GPIO_ACTIVE_HIGH>;
75 }; 75 };
76 76
77 consumer { 77 consumer {
78 enable-gpios = <&enable_delay 0 130000 78 enable-gpios = <&enable_delay 0 130000 30000>;
79 }; 79 };
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