freebsd-dev/share/man/man9/OF_device_from_xref.9
Edward Tomasz Napierala 604f1c416c Don't put multiple names on a single .Nm line. This fixes apropos(1)
output, from this:

strnlen, strlen, strlen,(3) - find length of string                                                                                                                                                     │·······

... to this:

strlen, strnlen(3) - find length of string

PR:		223525
MFC after:	2 weeks
2018-04-17 09:05:46 +00:00

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.\"
.\" Copyright (c) 2018 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
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.Dd April 9, 2018
.Dt OF_DEVICE_FROM_XREF 9
.Os
.Sh NAME
.Nm OF_device_from_xref ,
.Nm OF_xref_from_device ,
.Nm OF_device_register_xref
.Nd "manage mappings between xrefs and devices"
.Sh SYNOPSIS
.In dev/ofw/ofw_bus.h
.In dev/ofw/ofw_bus_subr.h
.Ft int
.Fn OF_device_register_xref "phandle_t xref" "device_t dev"
.Ft device_t
.Fn OF_device_from_xref "phandle_t xref"
.Ft phandle_t
.Fn OF_xref_from_device "device_t dev"
.Sh DESCRIPTION
.Pp
When a device tree node references another node, the driver may
need to get a device_t instance associated with the referenced node.
For instance, an Ethernet driver accessing a PHY device.
To make this possible, the kernel maintains a table that
maps effective handles to device_t instances.
.Pp
.Fn OF_device_register_xref
adds a map entry from the effective phandle
.Fa xref
to device
.Fa dev .
If a mapping entry for
.Fa xref
already exists, it is replaced with the new one.
The function always returns 0.
.Pp
.Fn OF_device_from_xref
returns a device_t instance associated with the effective phandle
.Fa xref .
If no such mapping exists, the function returns NULL.
.Pp
.Fn OF_xref_from_device
returns the effective phandle associated with the device
.Fa dev .
If no such mapping exists, the function returns 0.
.Sh EXAMPLES
.Bd -literal
static int
acmephy_attach(device_t dev)
{
phandle_t node;
/* PHY node is referenced from eth device, register it */
node = ofw_bus_get_node(dev);
OF_device_register_xref(OF_xref_from_node(node), dev);
return (0);
}
.Ed
.Sh SEE ALSO
.Xr OF_node_to_xref 9
.Sh AUTHORS
.An -nosplit
This manual page was written by
.An Oleksandr Tymoshenko Aq Mt gonzo@FreeBSD.org .