NAME¶

OF_finddevice — find node in device tree

SYNOPSIS¶

#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

phandle_t
OF_finddevice(const char *path);

DESCRIPTION¶

OF_finddevice() returns the phandle for the node specified by the path. Returns -1 if the path cannot be found in the tree.

CAVEATS¶

The return value should only be checked with equality operators (equal to, not equal to) and not relational comparison (less than, greater than ). There is a discrepancy between IEEE 1275 standard and FreeBSD's internal representation of a phandle: IEEE 1275 requires the return value of this function to be -1 if the path is not found. But phandle_t is an unsigned type, so it cannot be relationally compared with -1 or 0, this comparison is always true or always false.

EXAMPLES¶

    phandle_t root, i2c;

    root = OF_finddevice("/");
    i2c = OF_finddevice("/soc/axi/i2c@a0e0000");
    if (i2c != -1) {
        ...
    }

SEE ALSO¶

OF_child(9) OF_parent(9) OF_peer(9)

AUTHORS¶

This manual page was written by Oleksandr Tymoshenko <gonzo@FreeBSD.org>.