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.