fdt: Add fdtdec_get_uint64 to decode a 64-bit value from a property

It decodes a 64-bit value from a property that is at least 8 bytes long.

Signed-off-by: Che-Liang Chiou <clchiou@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/include/fdtdec.h b/include/fdtdec.h
index a37cf54..b5d7d2f 100644 (file)
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -181,6 +181,21 @@ fdt_addr_t fdtdec_get_addr(const void *blob, int node,
 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
                s32 default_val);
 
+/**
+ * Look up a 64-bit integer property in a node and return it. The property
+ * must have at least 8 bytes of data (2 cells). The first two cells are
+ * concatenated to form a 8 bytes value, where the first cell is top half and
+ * the second cell is bottom half.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name    name of property to find
+ * @param default_val  default value to return if the property is not found
+ * @return integer value, if found, or default_val if not
+ */
+uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
+               uint64_t default_val);
+
 /**
  * Checks whether a node is enabled.
  * This looks for a 'status' property. If this exists, then returns 1 if

diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index da12df2..150512e 100644 (file)
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -111,6 +111,19 @@ s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
        return default_val;
 }
 
+uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
+               uint64_t default_val)
+{
+       const uint64_t *cell64;
+       int length;
+
+       cell64 = fdt_getprop(blob, node, prop_name, &length);
+       if (!cell64 || length < sizeof(*cell64))
+               return default_val;
+
+       return fdt64_to_cpu(*cell64);
+}
+
 int fdtdec_get_is_enabled(const void *blob, int node)
 {
        const char *cell;