1 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/spi/spi-mux.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Generic SPI Multiplexer
8
9 description: |
10 This binding describes a SPI bus multiplexer to route the SPI chip select
11 signals. This can be used when you need more devices than the SPI controller
12 has chip selects available. An example setup is shown in ASCII art; the actual
13 setting of the multiplexer to a channel needs to be done by a specific SPI mux
14 driver.
15
16 MOSI /--------------------------------+--------+--------+--------\
17 MISO |/------------------------------+|-------+|-------+|-------\|
18 SCL ||/----------------------------+||------+||------+||------\||
19 ||| ||| ||| ||| |||
20 +------------+ ||| ||| ||| |||
21 | SoC ||| | +-+++-+ +-+++-+ +-+++-+ +-+++-+
22 | ||| | | dev | | dev | | dev | | dev |
23 | +--+++-+ | CS-X +------+\ +--+--+ +--+--+ +--+--+ +--+--+
24 | | SPI +-|-------+ Mux |\\ CS-0 | | | |
25 | +------+ | +--+---+\\\-------/ CS-1 | | |
26 | | | \\\----------------/ CS-2 | |
27 | +------+ | | \\-------------------------/ CS-3 |
28 | | ? +-|----------/ \----------------------------------/
29 | +------+ |
30 +------------+
31
32 allOf:
33 - $ref: /schemas/spi/spi-controller.yaml#
34 - $ref: /schemas/spi/spi-peripheral-props.yaml#
35
36 maintainers:
37 - Chris Packham <chris.packham@alliedtelesis.co.nz>
38
39 properties:
40 compatible:
41 const: spi-mux
42
43 mux-controls:
44 maxItems: 1
45
46 required:
47 - compatible
48 - reg
49 - spi-max-frequency
50 - mux-controls
51
52 unevaluatedProperties: false
53
54 examples:
55 - |
56 #include <dt-bindings/gpio/gpio.h>
57 mux: mux-controller {
58 compatible = "gpio-mux";
59 #mux-control-cells = <0>;
60
61 mux-gpios = <&gpio0 3 GPIO_ACTIVE_HIGH>;
62 };
63
64 spi {
65 #address-cells = <1>;
66 #size-cells = <0>;
67 spi@0 {
68 compatible = "spi-mux";
69 reg = <0>;
70 #address-cells = <1>;
71 #size-cells = <0>;
72 spi-max-frequency = <100000000>;
73
74 mux-controls = <&mux>;
75
76 flash@0 {
77 compatible = "jedec,spi-nor";
78 reg = <0>;
79 spi-max-frequency = <40000000>;
80 };
81
82 sensor@1 {
83 compatible = "bosch,bme680";
84 reg = <1>;
85 spi-max-frequency = <10000000>;
86 };
87 };
88 };
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