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 46When a device tree node references another node, the driver may 47need to get a device_t instance associated with the referenced node. 48For instance, an Ethernet driver accessing a PHY device. 49To make this possible, the kernel maintains a table that 50maps effective handles to device_t instances. 51.Pp 52.Fn OF_device_register_xref 53adds a map entry from the effective phandle 54.Fa xref 55to device 56.Fa dev . 57If a mapping entry for 58.Fa xref 59already exists, it is replaced with the new one. 60The function always returns 0. 61.Pp 62.Fn OF_device_from_xref 63returns a device_t instance associated with the effective phandle 64.Fa xref . 65If no such mapping exists, the function returns NULL. 66.Pp 67.Fn OF_xref_from_device 68returns the effective phandle associated with the device 69.Fa dev . 70If no such mapping exists, the function returns 0. 71.Sh EXAMPLES 72.Bd -literal 73 static int 74 acmephy_attach(device_t dev) 75 { 76 phandle_t node; 77 78 /* PHY node is referenced from eth device, register it */ 79 node = ofw_bus_get_node(dev); 80 OF_device_register_xref(OF_xref_from_node(node), dev); 81 82 return (0); 83 } 84.Ed 85.Sh SEE ALSO 86.Xr OF_node_to_xref 9 87.Sh AUTHORS 88.An -nosplit 89This manual page was written by 90.An Oleksandr Tymoshenko Aq Mt gonzo@FreeBSD.org . 91