1 == Introduction ==
2
3 Hardware modules that control pin multiplexing
4 such as pull-up/down, tri-state, drive-strengt
5 controllers. Each pin controller must be repre
6 just like any other hardware module.
7
8 Hardware modules whose signals are affected by
9 designated client devices. Again, each client
10 node in device tree, just like any other hardw
11
12 For a client device to operate correctly, cert
13 set up certain specific pin configurations. So
14 single static pin configuration, e.g. set up d
15 need to reconfigure pins at run-time, for exam
16 device is inactive. Hence, each client device
17 states. The number and names of those states i
18 own binding.
19
20 The common pinctrl bindings defined in this fi
21 for client device device tree nodes to map tho
22 configuration used by those states.
23
24 Note that pin controllers themselves may also
25 For example, a pin controller may set up its o
26 driver loads. This would allow representing a
27 in a single place, rather than splitting it ac
28 nodes. The decision to do this or not somewhat
29 individual board device tree files, and any re
30 bindings for the individual client devices in
31 they require certain specific named states for
32
33 == Pinctrl client devices ==
34
35 For each client device individually, every pin
36 ID. These numbers start at 0, and are contiguo
37 property exists to define the pin configuratio
38 assigned a name. When names are used, another
39 those names to the integer IDs.
40
41 Each client device's own binding determines th
42 defined in its device tree node, and whether t
43 IDs that must be provided, or whether to defin
44 must be provided.
45
46 Required properties:
47 pinctrl-0: List of phandles, each pointin
48 node. These referenced pin con
49 nodes of the pin controller th
50 entries may exist in this list
51 controllers may be configured,
52 from multiple nodes for a sing
53 contributing part of the overa
54 section of this document for d
55 pin configuration nodes.
56
57 In some cases, it may be usefu
58 to be empty. This may be requi
59 used in an SoC either without
60 pin controller does not affect
61 the binding for that IP block
62 exist, they must still be defi
63
64 Optional properties:
65 pinctrl-1: List of phandles, each pointin
66 node within a pin controller.
67 ...
68 pinctrl-n: List of phandles, each pointin
69 node within a pin controller.
70 pinctrl-names: The list of names to assign st
71 name for integer state ID 0, l
72 so on.
73
74 For example:
75
76 /* For a client device requiring named
77 device {
78 pinctrl-names = "active", "idl
79 pinctrl-0 = <&state_0_node_a>;
80 pinctrl-1 = <&state_1_node_a>,
81 };
82
83 /* For the same device if using state
84 device {
85 pinctrl-0 = <&state_0_node_a>;
86 pinctrl-1 = <&state_1_node_a>,
87 };
88
89 /*
90 * For an IP block whose binding suppo
91 * but in use on an SoC that doesn't h
92 */
93 device {
94 pinctrl-names = "active", "idl
95 pinctrl-0 = <>;
96 pinctrl-1 = <>;
97 };
98
99 == Pin controller devices ==
100
101 See pinctrl.yaml
102
103 == Generic pin multiplexing node content ==
104
105 See pinmux-node.yaml
106
107 == Generic pin configuration node content ==
108
109 See pincfg-node.yaml
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