xref: /freebsd/share/man/man9/OF_finddevice.9 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
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26ac32b99cSOleksandr Tymoshenko.Dd April 9, 2018
27ac32b99cSOleksandr Tymoshenko.Dt OF_FINDDEVICE 9
28ac32b99cSOleksandr Tymoshenko.Os
29ac32b99cSOleksandr Tymoshenko.Sh NAME
30ac32b99cSOleksandr Tymoshenko.Nm OF_finddevice
31ac32b99cSOleksandr Tymoshenko.Nd find node in device tree
32ac32b99cSOleksandr Tymoshenko.Sh SYNOPSIS
33ac32b99cSOleksandr Tymoshenko.In dev/ofw/ofw_bus.h
34ac32b99cSOleksandr Tymoshenko.In dev/ofw/ofw_bus_subr.h
35ac32b99cSOleksandr Tymoshenko.Ft phandle_t
36ac32b99cSOleksandr Tymoshenko.Fn OF_finddevice "const char *path"
37ac32b99cSOleksandr Tymoshenko.Sh DESCRIPTION
38ac32b99cSOleksandr Tymoshenko.Fn OF_finddevice
39ac32b99cSOleksandr Tymoshenkoreturns the phandle for the node specified by the
40ac32b99cSOleksandr Tymoshenko.Fa path .
41ac32b99cSOleksandr TymoshenkoReturns -1 if the path cannot be found in the tree.
42ac32b99cSOleksandr Tymoshenko.Sh EXAMPLES
43ac32b99cSOleksandr Tymoshenko.Bd -literal
44ac32b99cSOleksandr Tymoshenko    phandle_t root, i2c;
45ac32b99cSOleksandr Tymoshenko
46ac32b99cSOleksandr Tymoshenko    root = OF_finddevice("/");
47ac32b99cSOleksandr Tymoshenko    i2c = OF_finddevice("/soc/axi/i2c@a0e0000");
48ac32b99cSOleksandr Tymoshenko    if (i2c != -1) {
49ac32b99cSOleksandr Tymoshenko        ...
50ac32b99cSOleksandr Tymoshenko    }
51ac32b99cSOleksandr Tymoshenko.Ed
52ac32b99cSOleksandr Tymoshenko.Sh SEE ALSO
53*32068667SChristian Brueffer.Xr OF_child 9 ,
54*32068667SChristian Brueffer.Xr OF_parent 9 ,
55ac32b99cSOleksandr Tymoshenko.Xr OF_peer 9
56ac32b99cSOleksandr Tymoshenko.Sh AUTHORS
57ac32b99cSOleksandr Tymoshenko.An -nosplit
58ac32b99cSOleksandr TymoshenkoThis manual page was written by
59ac32b99cSOleksandr Tymoshenko.An Oleksandr Tymoshenko Aq Mt gonzo@FreeBSD.org .
603d265fceSGordon Bergling.Sh CAVEATS
613d265fceSGordon BerglingThe return value should only be checked with equality
623d265fceSGordon Berglingoperators (equal to, not equal to) and not relational comparison
633d265fceSGordon Bergling(less than, greater than ).
643d265fceSGordon BerglingThere is a discrepancy between IEEE 1275 standard and
653d265fceSGordon Bergling.Fx Ns 's
663d265fceSGordon Berglinginternal representation of a phandle: IEEE 1275
673d265fceSGordon Berglingrequires the return value of this function to be -1 if the path
683d265fceSGordon Berglingis not found.
693d265fceSGordon BerglingBut phandle_t is an unsigned type, so it cannot
703d265fceSGordon Berglingbe relationally compared with -1 or 0, this comparison
713d265fceSGordon Berglingis always true or always false.
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