xref: /freebsd/share/man/man9/fdt_pinctrl.9 (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
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29.Dd June 23, 2018
30.Dt fdt_pinctrl 9
31.Os
32.Sh NAME
33.Nm fdt_pinctrl
34.Nd helper functions for FDT pinmux controller drivers
35.Sh SYNOPSIS
36.In dev/fdt/fdt_pinctrl.h
37.Ft int
38.Fn fdt_pinctrl_configure "device_t client" "u_int index"
39.Ft int
40.Fn fdt_pinctrl_configure_by_name "device_t client" "const char * name"
41.Ft int
42.Fn fdt_pinctrl_register "device_t pinctrl" "const char *pinprop"
43.Ft int
44.Fn fdt_pinctrl_configure_tree "device_t pinctrl"
45.Sh DESCRIPTION
46.Xr fdt_pinctrl 4
47provides an API for manipulating I/O pin configurations on
48pinmux controllers and pinmux clients.
49On the controller side, the standard newbus probe and
50attach methods are implemented.
51As part of handling attach, it calls the
52.Fn fdt_pinctrl_register
53function to register itself as a pinmux controller.
54Then
55.Fn fdt_pinctrl_configure_tree
56is used to walk the device tree and configure pins specified by the pinctrl-0
57property for all active devices.
58The driver also implements the
59.Fn fdt_pinctrl_configure
60method, which allows client devices to change their
61pin configurations after startup.
62If a client device requires a pin configuration change at some
63point of its lifecycle, it uses the
64.Fn fdt_pinctrl_configure
65or
66.Fn fdt_pinctrl_configure_by_name
67functions.
68.Pp
69.Fn fdt_pinctrl_configure
70is used by client device
71.Fa client
72to request a pin configuration
73described by the pinctrl-N property with index
74.Fa index .
75.Pp
76.Fn fdt_pinctrl_configure_by_name
77is used by client device
78.Fa client
79to request the pin configuration with name
80.Fa name .
81.Pp
82.Fn fdt_pinctrl_register
83registers a pinctrl driver so that it can be used by other devices which call
84.Fn fdt_pinctrl_configure
85or
86.Fn fdt_pinctrl_configure_by_name .
87It also registers each child node of the pinctrl driver's node which contains
88a property with the name given in
89.Fa pinprop .
90If
91.Fa pinprop
92is
93.Dv NULL ,
94every descendant node is registered.
95It is possible for the driver to register itself
96as a pinmux controller for more than one pin property type
97by calling
98.Fn fdt_pinctrl_register
99multiple types.
100.Pp
101.Fn fdt_pinctrl_configure_tree
102walks through enabled devices in the device tree.
103If the pinctrl-0 property contains references
104to child nodes of the specified pinctrl device,
105their pins are configured.
106.Sh EXAMPLES
107.Bd -literal
108static int
109foo_configure_pins(device_t dev, phandle_t cfgxref)
110{
111	phandle_t cfgnode;
112	uint32_t *pins, *functions;
113	int npins, nfunctions;
114
115	cfgnode = OF_node_from_xref(cfgxref);
116	pins = NULL;
117	npins = OF_getencprop_alloc_multi(cfgnode, "foo,pins", sizeof(*pins),
118	    (void **)&pins);
119	functions = NULL;
120	nfunctions = OF_getencprop_alloc_multi(cfgnode, "foo,functions",
121	    sizeof(*functions), (void **)&functions);
122	...
123}
124
125static int
126foo_is_gpio(device_t dev, device_t gpiodev, bool *is_gpio)
127{
128	return (foo_is_pin_func_gpio(is_gpio));
129}
130
131static int
132foo_set_flags(device_t dev, device_t gpiodev, uint32_t pin, uint32_t flags)
133{
134	int rv;
135
136	rv = foo_is_pin_func_gpio(is_gpio);
137	if (rv != 0)
138		return (rv);
139	foo_set_flags(pin, flags);
140	return (0);
141}
142
143static int
144foo_get_flags(device_t dev, device_t gpiodev, uint32_t pin, uint32_t *flags)
145{
146	int rv;
147
148	rv = foo_is_pin_func_gpio(is_gpio);
149	if (rv != 0)
150		return (rv);
151	foo_get_flags(pin, flags);
152	return (0);
153}
154
155static int
156foo_attach(device_t dev)
157{
158	...
159
160	fdt_pinctrl_register(dev, "foo,pins");
161	/*
162	 * It is possible to register more than one pinprop handler
163	 */
164	fdt_pinctrl_register(dev, "bar,pins");
165	fdt_pinctrl_configure_tree(dev);
166
167	return (0);
168}
169
170static device_method_t foo_methods[] = {
171	...
172
173	/* fdt_pinctrl interface */
174	DEVMETHOD(fdt_pinctrl_configure, foo_configure_pins),
175	DEVMETHOD(fdt_pinctrl_is_gpio, foo_is_gpio),
176	DEVMETHOD(fdt_pinctrl_set_flags, foo_set_flags),
177	DEVMETHOD(fdt_pinctrl_get_flags, foo_get_flags),
178
179	/* Terminate method list */
180	DEVMETHOD_END
181};
182
183DRIVER_MODULE(foo, simplebus, foo_driver, foo_devclass, NULL, NULL);
184.Ed
185.Sh SEE ALSO
186.Xr fdt_pinctrl 4
187.Sh AUTHORS
188This manual page was written by
189.An Oleksandr Tymoshenko .
190