focal (9) fdt_pinctrl.9freebsd.gz

NAME

     fdt_pinctrl — helper functions for FDT pinmux controller drivers

SYNOPSIS

     #include <dev/fdt/fdt_pinctrl.h>

     int
     fdt_pinctrl_configure(device_t client, u_int index);

     int
     fdt_pinctrl_configure_by_name(device_t client, const char * name);

     int
     fdt_pinctrl_register(device_t pinctrl, const char *pinprop);

     int
     fdt_pinctrl_configure_tree(device_t pinctrl);

DESCRIPTION

     fdt_pinctrl(4) provides an API for manipulating I/O pin configurations on pinmux controllers and pinmux
     clients.  On the controller side, the standard newbus probe and attach methods are implemented.  As part of
     handling attach, it calls the fdt_pinctrl_register() function to register itself as a pinmux controller.
     Then fdt_pinctrl_configure_tree() is used to walk the device tree and configure pins specified by the
     pinctrl-0 property for all active devices.  The driver also implements the fdt_pinctrl_configure() method,
     which allows client devices to change their pin configurations after startup.  If a client device requires
     a pin configuration change at some point of its lifecycle, it uses the fdt_pinctrl_configure() or
     fdt_pinctrl_configure_by_name() functions.

     fdt_pinctrl_configure() is used by client device client to request a pin configuration described by the
     pinctrl-N property with index index.

     fdt_pinctrl_configure_by_name() is used by client device client to request the pin configuration with name
     name.

     fdt_pinctrl_register() registers a pinctrl driver so that it can be used by other devices which call
     fdt_pinctrl_configure() or fdt_pinctrl_configure_by_name().  It also registers each child node of the
     pinctrl driver's node which contains a property with the name given in pinprop.  If pinprop is NULL, every
     descendant node is registered.  It is possible for the driver to register itself as a pinmux controller for
     more than one pin property type by calling fdt_pinctrl_register() multiple types.

     fdt_pinctrl_configure_tree() walks through enabled devices in the device tree.  If the pinctrl-0 property
     contains references to child nodes of the specified pinctrl device, their pins are configured.

EXAMPLES

     static int
     foo_configure_pins(device_t dev, phandle_t cfgxref)
     {
             phandle_t cfgnode;
             uint32_t *pins, *functions;
             int npins, nfunctions;

             cfgnode = OF_node_from_xref(cfgxref);
             pins = NULL;
             npins = OF_getencprop_alloc_multi(cfgnode, "foo,pins", sizeof(*pins),
                 (void **)&pins);
             functions = NULL;
             nfunctions = OF_getencprop_alloc_multi(cfgnode, "foo,functions",
                 sizeof(*functions), (void **)&functions);
             ...
     }

     static int
     foo_attach(device_t dev)
     {
             ...

             fdt_pinctrl_register(dev, "foo,pins");
             /*
              * It is possible to register more than one pinprop handler
              */
             fdt_pinctrl_register(dev, "bar,pins");
             fdt_pinctrl_configure_tree(dev);

             return (0);
     }

     static device_method_t foo_methods[] = {
             ...

             /* fdt_pinctrl interface */
             DEVMETHOD(fdt_pinctrl_configure, foo_configure_pins),

             /* Terminate method list */
             DEVMETHOD_END
     };

     DRIVER_MODULE(foo, simplebus, foo_driver, foo_devclass, NULL, NULL);

SEE ALSO

     fdt_pinctrl(4),

AUTHORS

     This manual page was written by Oleksandr Tymoshenko.