NAME
fdt_pinctrl — helper functions for FDT pinmux controller driversSYNOPSIS
#include <dev/fdt/fdt_pinctrl.h> intfdt_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 isNULL, 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_is_gpio(device_t dev, device_t gpiodev, bool *is_gpio)
{
return (foo_is_pin_func_gpio(is_gpio));
}
static int
foo_set_flags(device_t dev, device_t gpiodev, uint32_t pin, uint32_t flags)
{
int rv;
rv = foo_is_pin_func_gpio(is_gpio);
if (rv != 0)
return (rv);
foo_set_flags(pin, flags);
return (0);
}
static int
foo_get_flags(device_t dev, device_t gpiodev, uint32_t pin, uint32_t *flags)
{
int rv;
rv = foo_is_pin_func_gpio(is_gpio);
if (rv != 0)
return (rv);
foo_get_flags(pin, flags);
return (0);
}
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),
DEVMETHOD(fdt_pinctrl_is_gpio, foo_is_gpio),
DEVMETHOD(fdt_pinctrl_set_flags, foo_set_flags),
DEVMETHOD(fdt_pinctrl_get_flags, foo_get_flags),
/* 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.| June 23, 2018 | Debian |