1.\" 2.\" Copyright (c) 2018 Oleksandr Tymoshenko <gonzo@FreeBSD.org> 3.\" 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd April 9, 2018 29.Dt OF_DEVICE_FROM_XREF 9 30.Os 31.Sh NAME 32.Nm OF_device_from_xref , 33.Nm OF_xref_from_device , 34.Nm OF_device_register_xref 35.Nd "manage mappings between xrefs and devices" 36.Sh SYNOPSIS 37.In dev/ofw/ofw_bus.h 38.In dev/ofw/ofw_bus_subr.h 39.Ft int 40.Fn OF_device_register_xref "phandle_t xref" "device_t dev" 41.Ft device_t 42.Fn OF_device_from_xref "phandle_t xref" 43.Ft phandle_t 44.Fn OF_xref_from_device "device_t dev" 45.Sh DESCRIPTION 46.Pp 47When a device tree node references another node, the driver may 48need to get a device_t instance associated with the referenced node. 49For instance, an Ethernet driver accessing a PHY device. 50To make this possible, the kernel maintains a table that 51maps effective handles to device_t instances. 52.Pp 53.Fn OF_device_register_xref 54adds a map entry from the effective phandle 55.Fa xref 56to device 57.Fa dev . 58If a mapping entry for 59.Fa xref 60already exists, it is replaced with the new one. 61The function always returns 0. 62.Pp 63.Fn OF_device_from_xref 64returns a device_t instance associated with the effective phandle 65.Fa xref . 66If no such mapping exists, the function returns NULL. 67.Pp 68.Fn OF_xref_from_device 69returns the effective phandle associated with the device 70.Fa dev . 71If no such mapping exists, the function returns 0. 72.Sh EXAMPLES 73.Bd -literal 74 static int 75 acmephy_attach(device_t dev) 76 { 77 phandle_t node; 78 79 /* PHY node is referenced from eth device, register it */ 80 node = ofw_bus_get_node(dev); 81 OF_device_register_xref(OF_xref_from_node(node), dev); 82 83 return (0); 84 } 85.Ed 86.Sh SEE ALSO 87.Xr OF_node_to_xref 9 88.Sh AUTHORS 89.An -nosplit 90This manual page was written by 91.An Oleksandr Tymoshenko Aq Mt gonzo@FreeBSD.org . 92