bindings/gpio/gpio-latch.yaml

   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     };