fdt: Add resource parsing functions
Add the fdt_get_resource() and fdt_get_named_resource() functions which
can be used to parse resources (memory regions) from an FDT. A helper to
compute the size of a region is also provided.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 2590d30..8b24deb 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -40,6 +40,27 @@
fdt_addr_t end;
};
+/*
+ * Information about a resource. start is the first address of the resource
+ * and end is the last address (inclusive). The length of the resource will
+ * be equal to: end - start + 1.
+ */
+struct fdt_resource {
+ fdt_addr_t start;
+ fdt_addr_t end;
+};
+
+/**
+ * Compute the size of a resource.
+ *
+ * @param res the resource to operate on
+ * @return the size of the resource
+ */
+static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
+{
+ return res->end - res->start + 1;
+}
+
/**
* Compat types that we know about and for which we might have drivers.
* Each is named COMPAT_<dir>_<filename> where <dir> is the directory
@@ -597,4 +618,35 @@
*/
int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
struct fmap_entry *entry);
+
+/**
+ * Obtain an indexed resource from a device property.
+ *
+ * @param fdt FDT blob
+ * @param node node to examine
+ * @param property name of the property to parse
+ * @param index index of the resource to retrieve
+ * @param res returns the resource
+ * @return 0 if ok, negative on error
+ */
+int fdt_get_resource(const void *fdt, int node, const char *property,
+ unsigned int index, struct fdt_resource *res);
+
+/**
+ * Obtain a named resource from a device property.
+ *
+ * Look up the index of the name in a list of strings and return the resource
+ * at that index.
+ *
+ * @param fdt FDT blob
+ * @param node node to examine
+ * @param property name of the property to parse
+ * @param prop_names name of the property containing the list of names
+ * @param name the name of the entry to look up
+ * @param res returns the resource
+ */
+int fdt_get_named_resource(const void *fdt, int node, const char *property,
+ const char *prop_names, const char *name,
+ struct fdt_resource *res);
+
#endif