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dt-bindings: gpio: Add gpio-latch binding document

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This adds a binding for a GPIO multiplexer driver based on latches
connected to other GPIOs.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Sascha Hauer 2022-10-07 13:46:47 +02:00 committed by Bartosz Golaszewski
parent e7f758fa9b
commit 2a903ca922
1 changed files with 94 additions and 0 deletions
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Documentation/devicetree/bindings/gpio/gpio-latch.yaml Normal file
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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/gpio/gpio-latch.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: GPIO latch controller
maintainers:
- Sascha Hauer <s.hauer@pengutronix.de>
description: |
This binding describes a GPIO multiplexer based on latches connected to
other GPIOs, like this:
CLK0 ----------------------. ,--------.
CLK1 -------------------. `--------|> #0 |
| | |
OUT0 ----------------+--|-----------|D0 Q0|-----|<
OUT1 --------------+-|--|-----------|D1 Q1|-----|<
OUT2 ------------+-|-|--|-----------|D2 Q2|-----|<
OUT3 ----------+-|-|-|--|-----------|D3 Q3|-----|<
OUT4 --------+-|-|-|-|--|-----------|D4 Q4|-----|<
OUT5 ------+-|-|-|-|-|--|-----------|D5 Q5|-----|<
OUT6 ----+-|-|-|-|-|-|--|-----------|D6 Q6|-----|<
OUT7 --+-|-|-|-|-|-|-|--|-----------|D7 Q7|-----|<
| | | | | | | | | `--------'
| | | | | | | | |
| | | | | | | | | ,--------.
| | | | | | | | `-----------|> #1 |
| | | | | | | | | |
| | | | | | | `--------------|D0 Q0|-----|<
| | | | | | `----------------|D1 Q1|-----|<
| | | | | `------------------|D2 Q2|-----|<
| | | | `--------------------|D3 Q3|-----|<
| | | `----------------------|D4 Q4|-----|<
| | `------------------------|D5 Q5|-----|<
| `--------------------------|D6 Q6|-----|<
`----------------------------|D7 Q7|-----|<
`--------'
The number of clk-gpios and latched-gpios is not fixed. The actual number
of number of latches and the number of inputs per latch is derived from
the number of GPIOs given in the corresponding device tree properties.
properties:
compatible:
const: gpio-latch
"#gpio-cells":
const: 2
clk-gpios:
description: Array of GPIOs to be used to clock a latch
latched-gpios:
description: Array of GPIOs to be used as inputs per latch
setup-duration-ns:
description: Delay in nanoseconds to wait after the latch inputs have been
set up
clock-duration-ns:
description: Delay in nanoseconds to wait between clock output changes
gpio-controller: true
gpio-line-names: true
required:
- compatible
- "#gpio-cells"
- gpio-controller
- clk-gpios
- latched-gpios
additionalProperties: false
examples:
- |
gpio-latch {
#gpio-cells = <2>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_di_do_leds>;
compatible = "gpio-latch";
gpio-controller;
setup-duration-ns = <100>;
clock-duration-ns = <100>;
clk-gpios = <&gpio3 7 0>, <&gpio3 8 0>;
latched-gpios = <&gpio3 21 0>, <&gpio3 22 0>,
<&gpio3 23 0>, <&gpio3 24 0>,
<&gpio3 25 0>, <&gpio3 26 0>,
<&gpio3 27 0>, <&gpio3 28 0>;
};