xref: /freebsd/share/man/man9/fdt_pinctrl.9 (revision 74ca7bf1d4c7173d5575ba168bc4b5f6d181ff5a)
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31.Dd March 3, 2018
32.Dt fdt_pinctrl 9
33.Os
34.Sh NAME
35.Nm fdt_pinctrl
36.Nd helper functions for FDT pinmux controller drivers
37.Sh SYNOPSIS
38.In dev/fdt/fdt_pinctrl.h
39.Ft int
40.Fn fdt_pinctrl_configure "device_t client" "u_int index"
41.Ft int
42.Fn fdt_pinctrl_configure_by_name "device_t client" "const char * name"
43.Ft int
44.Fn fdt_pinctrl_register "device_t pinctrl" "const char *pinprop"
45.Ft int
46.Fn fdt_pinctrl_configure_tree "device_t pinctrl"
47.Sh DESCRIPTION
48.Xr fdt_pinctrl 4
49provides an API for manipulating I/O pin configurations on
50pinmux controllers and pinmux clients.
51On the controller side, the standard newbus probe and
52attach methods are implemented.
53As part of handling attach, it calls the
54.Fn fdt_pinctrl_register
55function to register itself as a pinmux controller.
56Then
57.Fn fdt_pinctrl_configure_tree
58is used to walk the device tree and configure pins specified by the pinctrl-0
59property for all active devices.
60The driver also implements the
61.Fn fdt_pinctrl_configure
62method, which allows client devices to change their
63pin configurations after startup.
64If a client device requires a pin configuration change at some
65point of its lifecycle, it uses the
66.Fn fdt_pinctrl_configure
67or
68.Fn fdt_pinctrl_configure_by_name
69functions.
70.Pp
71.Fn fdt_pinctrl_configure
72is used by client device
73.Fa client
74to request a pin configuration
75described by the pinctrl-N property with index
76.Fa index .
77.Pp
78.Fn fdt_pinctrl_configure_by_name
79is used by client device
80.Fa client
81to request the pin configuration with name
82.Fa name .
83.Pp
84.Fn fdt_pinctrl_register
85registers a pinctrl driver so that it can be used by other devices which call
86.Fn fdt_pinctrl_configure
87or
88.Fn fdt_pinctrl_configure_by_name .
89It also registers each child node of the pinctrl driver's node which contains
90a property with the name given in
91.Fa pinprop .
92If
93.Fa pinprop
94is
95.Dv NULL ,
96every descendant node is registered.
97It is possible for the driver to register itself
98as a pinmux controller for more than one pin property type
99by calling
100.Fn fdt_pinctrl_register
101multiple types.
102.Pp
103.Fn fdt_pinctrl_configure_tree
104walks through enabled devices in the device tree.
105If the pinctrl-0 property contains references
106to child nodes of the specified pinctrl device,
107their pins are configured.
108.Sh EXAMPLES
109.Bd -literal
110static int
111foo_configure_pins(device_t dev, phandle_t cfgxref)
112{
113	phandle_t cfgnode;
114	uint32_t *pins, *functions;
115	int npins, nfunctions;
116
117	cfgnode = OF_node_from_xref(cfgxref);
118	pins = NULL;
119	npins = OF_getencprop_alloc(cfgnode, "foo,pins", sizeof(*pins),
120	    (void **)&pins);
121	functions = NULL;
122	nfunctions = OF_getencprop_alloc(cfgnode, "foo,functions",
123	    sizeof(*functions), (void **)&functions);
124	...
125}
126
127static int
128foo_attach(device_t dev)
129{
130	...
131
132	fdt_pinctrl_register(dev, "foo,pins");
133	/*
134	 * It is possible to register more than one pinprop handler
135	 */
136	fdt_pinctrl_register(dev, "bar,pins");
137	fdt_pinctrl_configure_tree(dev);
138
139	return (0);
140}
141
142static device_method_t foo_methods[] = {
143	...
144
145	/* fdt_pinctrl interface */
146	DEVMETHOD(fdt_pinctrl_configure, foo_configure_pins),
147
148	/* Terminate method list */
149	DEVMETHOD_END
150};
151
152DRIVER_MODULE(foo, simplebus, foo_driver, foo_devclass, NULL, NULL);
153.Ed
154.Sh SEE ALSO
155.Xr fdt_pinctrl 4 ,
156.Sh AUTHORS
157This manual page was written by
158.An Oleksandr Tymoshenko .
159