Lines Matching +full:i2c +full:- +full:controller
1 Common multiplexer controller bindings
4 A multiplexer (or mux) controller will have one, or several, consumer devices
5 that uses the mux controller. Thus, a mux controller can possibly control
7 multiplexer needed by each consumer, but a single mux controller can of course
10 A mux controller provides a number of states to its consumers, and the state
11 space is a simple zero-based enumeration. I.e. 0-1 for a 2-way multiplexer,
12 0-7 for an 8-way multiplexer, etc.
16 ---------
18 Mux controller consumers should specify a list of mux controllers that they
19 want to use with a property containing a 'mux-ctrl-list':
21 mux-ctrl-list ::= <single-mux-ctrl> [mux-ctrl-list]
22 single-mux-ctrl ::= <mux-ctrl-phandle> [mux-ctrl-specifier]
23 mux-ctrl-phandle : phandle to mux controller node
24 mux-ctrl-specifier : array of #mux-control-cells specifying the
25 given mux controller (controller specific)
27 Mux controller properties should be named "mux-controls". The exact meaning of
28 each mux controller property must be documented in the device tree binding for
29 each consumer. An optional property "mux-control-names" may contain a list of
30 strings to label each of the mux controllers listed in the "mux-controls"
33 Drivers for devices that use more than a single mux controller can use the
34 "mux-control-names" property to map the name of the requested mux controller
35 to an index into the list given by the "mux-controls" property.
37 mux-ctrl-specifier typically encodes the chip-relative mux controller number.
38 If the mux controller chip only provides a single mux controller, the
39 mux-ctrl-specifier can typically be left out.
43 /* One consumer of a 2-way mux controller (one GPIO-line) */
44 mux: mux-controller {
45 compatible = "gpio-mux";
46 #mux-control-cells = <0>;
48 mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>;
51 adc-mux {
52 compatible = "io-channel-mux";
53 io-channels = <&adc 0>;
54 io-channel-names = "parent";
56 mux-controls = <&mux>;
57 mux-control-names = "adc";
62 Note that in the example above, specifying the "mux-control-names" is redundant
63 because there is only one mux controller in the list. However, if the driver
64 for the consumer node in fact asks for a named mux controller, that name is of
68 * Two consumers (one for an ADC line and one for an i2c bus) of
69 * parallel 4-way multiplexers controlled by the same two GPIO-lines.
71 mux: mux-controller {
72 compatible = "gpio-mux";
73 #mux-control-cells = <0>;
75 mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
79 adc-mux {
80 compatible = "io-channel-mux";
81 io-channels = <&adc 0>;
82 io-channel-names = "parent";
84 mux-controls = <&mux>;
86 channels = "sync-1", "in", "out", "sync-2";
89 i2c-mux {
90 compatible = "i2c-mux";
91 i2c-parent = <&i2c1>;
93 mux-controls = <&mux>;
95 #address-cells = <1>;
96 #size-cells = <0>;
98 i2c@0 {
100 #address-cells = <1>;
101 #size-cells = <0>;
108 i2c@3 {
110 #address-cells = <1>;
111 #size-cells = <0>;
120 Mux controller nodes
121 --------------------
123 Mux controller nodes must specify the number of cells used for the
124 specifier using the '#mux-control-cells' property.
126 Optionally, mux controller nodes can also specify the state the mux should
127 have when it is idle. The idle-state property is used for this. If the
128 idle-state is not present, the mux controller is typically left as is when
130 idle-state property is an array with one idle state for each mux controller.
132 The special value (-1) may be used to indicate that the mux should be left
134 mux controller chips with more than one mux controller, particularly when
135 there is a need to "step past" a mux controller and set some other idle
136 state for a mux controller with a higher index.
139 multiplexer. Using this disconnected high-impedance state as the idle state
140 is indicated with idle state (-2).
144 #include <dt-bindings/mux/mux.h>
146 as MUX_IDLE_AS_IS (-1) and MUX_IDLE_DISCONNECT (-2).
148 An example mux controller node look like this (the adg972a chip is a triple
149 4-way multiplexer):
151 mux: mux-controller@50 {
154 #mux-control-cells = <1>;
156 idle-state = <MUX_IDLE_DISCONNECT MUX_IDLE_AS_IS 2>;