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-latch.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: GPIO latch controller
8
9 maintainers:
10 - Sascha Hauer <s.hauer@pengutronix.de>
11
12 description: |
13 This binding describes a GPIO multiplexer based on latches connected to
14 other GPIOs, like this:
15
16 CLK0 ----------------------. ,--------.
17 CLK1 -------------------. `--------|> #0 |
18 | | |
19 OUT0 ----------------+--|-----------|D0 Q0|-----|<
20 OUT1 --------------+-|--|-----------|D1 Q1|-----|<
21 OUT2 ------------+-|-|--|-----------|D2 Q2|-----|<
22 OUT3 ----------+-|-|-|--|-----------|D3 Q3|-----|<
23 OUT4 --------+-|-|-|-|--|-----------|D4 Q4|-----|<
24 OUT5 ------+-|-|-|-|-|--|-----------|D5 Q5|-----|<
25 OUT6 ----+-|-|-|-|-|-|--|-----------|D6 Q6|-----|<
26 OUT7 --+-|-|-|-|-|-|-|--|-----------|D7 Q7|-----|<
27 | | | | | | | | | `--------'
28 | | | | | | | | |
29 | | | | | | | | | ,--------.
30 | | | | | | | | `-----------|> #1 |
31 | | | | | | | | | |
32 | | | | | | | `--------------|D0 Q0|-----|<
33 | | | | | | `----------------|D1 Q1|-----|<
34 | | | | | `------------------|D2 Q2|-----|<
35 | | | | `--------------------|D3 Q3|-----|<
36 | | | `----------------------|D4 Q4|-----|<
37 | | `------------------------|D5 Q5|-----|<
38 | `--------------------------|D6 Q6|-----|<
39 `----------------------------|D7 Q7|-----|<
40 `--------'
41
42 The number of clk-gpios and latched-gpios is not fixed. The actual number
43 of number of latches and the number of inputs per latch is derived from
44 the number of GPIOs given in the corresponding device tree properties.
45
46 properties:
47 compatible:
48 const: gpio-latch
49 "#gpio-cells":
50 const: 2
51
52 clk-gpios:
53 description: Array of GPIOs to be used to clock a latch
54
55 latched-gpios:
56 description: Array of GPIOs to be used as inputs per latch
57
58 setup-duration-ns:
59 description: Delay in nanoseconds to wait after the latch inputs have been
60 set up
61
62 clock-duration-ns:
63 description: Delay in nanoseconds to wait between clock output changes
64
65 gpio-controller: true
66
67 gpio-line-names: true
68
69 required:
70 - compatible
71 - "#gpio-cells"
72 - gpio-controller
73 - clk-gpios
74 - latched-gpios
75
76 additionalProperties: false
77
78 examples:
79 - |
80 gpio-latch {
81 #gpio-cells = <2>;
82 pinctrl-names = "default";
83 pinctrl-0 = <&pinctrl_di_do_leds>;
84 compatible = "gpio-latch";
85 gpio-controller;
86 setup-duration-ns = <100>;
87 clock-duration-ns = <100>;
88
89 clk-gpios = <&gpio3 7 0>, <&gpio3 8 0>;
90 latched-gpios = <&gpio3 21 0>, <&gpio3 22 0>,
91 <&gpio3 23 0>, <&gpio3 24 0>,
92 <&gpio3 25 0>, <&gpio3 26 0>,
93 <&gpio3 27 0>, <&gpio3 28 0>;
94 };
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