libfdt: Bring in upstream stringlist functions

These have now landed upstream. The naming is different and in one case the
function signature has changed. Update the code to match.

This applies the following upstream commits by
Thierry Reding <treding@nvidia.com> :

   604e61e fdt: Add functions to retrieve strings
   8702bd1 fdt: Add a function to get the index of a string
   2218387 fdt: Add a function to count strings

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 53 insertions, 33 deletions

diff --git a/include/libfdt.h b/include/libfdt.h
index 3b1c788f49..f3b61c9427 100644
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -121,12 +121,17 @@
 	/* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
 	 * or similar property with a bad format or value */
 
-#define FDT_ERR_TOODEEP		15
+#define FDT_ERR_BADVALUE	15
+	/* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
+	 * value. For example: a property expected to contain a string list
+	 * is not NUL-terminated within the length of its value. */
+
+#define FDT_ERR_TOODEEP		16
 	/* FDT_ERR_TOODEEP: The depth of a node has exceeded the internal
 	 * libfdt limit. This can happen if you have more than
 	 * FDT_MAX_DEPTH nested nodes. */
 
-#define FDT_ERR_MAX		15
+#define FDT_ERR_MAX		16
 
 /**********************************************************************/
 /* Low-level functions (you probably don't need these)                */
@@ -957,51 +962,66 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
 
 /**
- * fdt_count_strings - count the number of strings in a string list
+ * fdt_stringlist_count - count the number of strings in a string list
  * @fdt: pointer to the device tree blob
- * @node: offset of the node
+ * @nodeoffset: offset of a tree node
  * @property: name of the property containing the string list
- * @return: the number of strings in the given property
+ * @return:
+ *   the number of strings in the given property
+ *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
+ *   -FDT_ERR_NOTFOUND if the property does not exist
  */
-int fdt_count_strings(const void *fdt, int node, const char *property);
+int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
 
 /**
- * fdt_find_string - find a string in a string list and return its index
+ * fdt_stringlist_search - find a string in a string list and return its index
  * @fdt: pointer to the device tree blob
- * @node: offset of the node
+ * @nodeoffset: offset of a tree node
  * @property: name of the property containing the string list
  * @string: string to look up in the string list
- * @return: the index of the string or negative on error
+ *
+ * Note that it is possible for this function to succeed on property values
+ * that are not NUL-terminated. That's because the function will stop after
+ * finding the first occurrence of @string. This can for example happen with
+ * small-valued cell properties, such as #address-cells, when searching for
+ * the empty string.
+ *
+ * @return:
+ *   the index of the string in the list of strings
+ *   -FDT_ERR_BADVALUE if the property value is not NUL-terminated
+ *   -FDT_ERR_NOTFOUND if the property does not exist or does not contain
+ *                     the given string
  */
-int fdt_find_string(const void *fdt, int node, const char *property,
-		    const char *string);
+int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
+			  const char *string);
 
 /**
- * fdt_get_string_index() - obtain the string at a given index in a string list
+ * fdt_stringlist_get() - obtain the string at a given index in a string list
  * @fdt: pointer to the device tree blob
- * @node: offset of the node
+ * @nodeoffset: offset of a tree node
  * @property: name of the property containing the string list
  * @index: index of the string to return
- * @output: return location for the string
- * @return: 0 if the string was found or a negative error code otherwise
- */
-int fdt_get_string_index(const void *fdt, int node, const char *property,
-			 int index, const char **output);
-
-/**
- * fdt_get_string() - obtain the first string in a string list
- * @fdt: pointer to the device tree blob
- * @node: offset of the node
- * @property: name of the property containing the string list
- * @output: return location for the string
- * @return: 0 if the string was found or a negative error code otherwise
- *
- * This is a shortcut for:
- *
- *	fdt_get_string_index(fdt, node, property, 0, output).
- */
-int fdt_get_string(const void *fdt, int node, const char *property,
-		   const char **output);
+ * @lenp: return location for the string length or an error code on failure
+ *
+ * Note that this will successfully extract strings from properties with
+ * non-NUL-terminated values. For example on small-valued cell properties
+ * this function will return the empty string.
+ *
+ * If non-NULL, the length of the string (on success) or a negative error-code
+ * (on failure) will be stored in the integer pointer to by lenp.
+ *
+ * @return:
+ *   A pointer to the string at the given index in the string list or NULL on
+ *   failure. On success the length of the string will be stored in the memory
+ *   location pointed to by the lenp parameter, if non-NULL. On failure one of
+ *   the following negative error codes will be returned in the lenp parameter
+ *   (if non-NULL):
+ *     -FDT_ERR_BADVALUE if the property value is not NUL-terminated
+ *     -FDT_ERR_NOTFOUND if the property does not exist
+ */
+const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
+			       const char *property, int index,
+			       int *lenp);
 
 /**********************************************************************/
 /* Read-only functions (addressing related)                           */