Function fdt_path_offset 

pub unsafe extern "C" fn fdt_path_offset(
    fdt: *const c_void,
    path: *const c_char,
) -> c_int

fdt_path_offset - find a tree node by its full path @fdt: pointer to the device tree blob @path: full path of the node to locate

fdt_path_offset() finds a node of a given path in the device tree. Each path component may omit the unit address portion, but the results of this are undefined if any such path component is ambiguous (that is if there are multiple nodes at the relevant level matching the given component, differentiated only by unit address).

If the path is not absolute (i.e. does not begin with ‘/’), the first component is treated as an alias. That is, the property by that name is looked up in the /aliases node, and the value of that property used in place of that first component.

For example, for this small fragment

/ { aliases { i2c2 = &foo; // RHS compiles to “/soc@0/i2c@30a40000/eeprom@52” }; soc@0 { foo: i2c@30a40000 { bar: eeprom@52 { }; }; }; };

these would be equivalent:

/soc@0/i2c@30a40000/eeprom@52 i2c2/eeprom@52

returns: structure block offset of the node with the requested path (>=0), on success -FDT_ERR_BADPATH, given path does not begin with ‘/’ and the first component is not a valid alias -FDT_ERR_NOTFOUND, if the requested node does not exist -FDT_ERR_BADMAGIC, -FDT_ERR_BADVERSION, -FDT_ERR_BADSTATE, -FDT_ERR_BADSTRUCTURE, -FDT_ERR_TRUNCATED, standard meanings.