This patch documents a few more functions in libfdt.h.  All the
read-only functions are now documented.

Signed-off-by: David Gibson <[EMAIL PROTECTED]>

Index: dtc/libfdt/libfdt.h
===================================================================
--- dtc.orig/libfdt/libfdt.h    2007-11-06 10:37:44.000000000 +1100
+++ dtc/libfdt/libfdt.h 2007-11-07 11:52:27.000000000 +1100
@@ -515,12 +515,107 @@
  */
 int fdt_parent_offset(const void *fdt, int nodeoffset);
 
+/**
+ * fdt_node_offset_by_prop_value - find nodes with a given property value
+ * @fdt: pointer to the device tree blob
+ * @startoffset: only find nodes after this offset
+ * @propname: property name to check
+ * @propval: property value to search for
+ * @proplen: length of the value in propval
+ *
+ * fdt_node_offset_by_prop_value() returns the offset of the first
+ * node after startoffset, which has a property named propname whose
+ * value is of length proplen and has value equal to propval; or if
+ * startoffset is -1, the very first such node in the tree.
+ *
+ * To iterate through all nodes matching the criterion, the following
+ * idiom can be used:
+ *     offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
+ *                                            propval, proplen);
+ *     while (offset != -FDT_ERR_NOTFOUND) {
+ *             // other code here
+ *             offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
+ *                                                    propval, proplen);
+ *     }
+ *
+ * Note the -1 in the first call to the function, if 0 is used here
+ * instead, the function will never locate the root node, even if it
+ * matches the criterion.
+ *
+ * returns:
+ *     structure block offset of the located node (>= 0, >startoffset),
+ *              on success
+ *     -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
+ *             tree after startoffset
+ *     -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_BADSTRUCTURE, standard meanings
+ */
 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
                                  const char *propname,
                                  const void *propval, int proplen);
 
+/**
+ * fdt_node_check_compatible: check a node's compatible property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of a tree node
+ * @compatible: string to match against
+ *
+ *
+ * fdt_node_check_compatible() returns 0 if the given node contains a
+ * 'compatible' property with the given string as one of its elements,
+ * it returns non-zero otherwise, or on error.
+ *
+ * returns:
+ *     0, if the node has a 'compatible' property listing the given string
+ *     1, if the node has a 'compatible' property, but it does not list
+ *             the given string
+ *     -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
+ *     -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_BADSTRUCTURE, standard meanings
+ */
 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
                              const char *compatible);
+
+/**
+ * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
+ * @fdt: pointer to the device tree blob
+ * @startoffset: only find nodes after this offset
+ * @compatible: 'compatible' string to match against
+ *
+ * fdt_node_offset_by_compatible() returns the offset of the first
+ * node after startoffset, which has a 'compatible' property which
+ * lists the given compatible string; or if startoffset is -1, the
+ * very first such node in the tree.
+ *
+ * To iterate through all nodes matching the criterion, the following
+ * idiom can be used:
+ *     offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
+ *     while (offset != -FDT_ERR_NOTFOUND) {
+ *             // other code here
+ *             offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
+ *     }
+ *
+ * Note the -1 in the first call to the function, if 0 is used here
+ * instead, the function will never locate the root node, even if it
+ * matches the criterion.
+ *
+ * returns:
+ *     structure block offset of the located node (>= 0, >startoffset),
+ *              on success
+ *     -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
+ *             tree after startoffset
+ *     -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_BADSTRUCTURE, standard meanings
+ */
 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
                                  const char *compatible);
 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson
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