jammy (9) OF_finddevice.9freebsd.gz

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>.