[Qemu-ppc] [PATCH 1/6] fdt_support: split fdt_getprop_u32_default

[Alexander Graf]

We already have a nice helper to give us a property cell value with default
fall back from a path. Split that into two helpers - one for the old path
based lookup and one to give us a value based on a node offset.

Signed-off-by: Alexander Graf <address@hidden>
---
 common/fdt_support.c  |   38 ++++++++++++++++++++++++++++++++------
 include/fdt_support.h |    2 ++
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/common/fdt_support.c b/common/fdt_support.c
index f9f358e..cc0bf76 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -50,6 +50,37 @@ static void write_cell(u8 *addr, u64 val, int size)
 }
 
 /**
+ * fdt_getprop_u32_default_node - Return a node's property or a default
+ *
+ * @fdt: ptr to device tree
+ * @off: offset of node
+ * @cell: cell offset in property
+ * @prop: property name
+ * @dflt: default value if the property isn't found
+ *
+ * Convenience function to return a node's property or a default value if
+ * the property doesn't exist.
+ */
+u32 fdt_getprop_u32_default_node(const void *fdt, int off, int cell,
+                               const char *prop, const u32 dflt)
+{
+       const fdt32_t *val;
+       int len;
+
+       val = fdt_getprop(fdt, off, prop, &len);
+
+       /* Check if property exists */
+       if (!val)
+               return dflt;
+
+       /* Check if property is long enough */
+       if (len < ((cell + 1) * sizeof(uint32_t)))
+               return dflt;
+
+       return fdt32_to_cpu(*val);
+}
+
+/**
  * fdt_getprop_u32_default - Find a node and return it's property or a default
  *
  * @fdt: ptr to device tree
@@ -63,18 +94,13 @@ static void write_cell(u8 *addr, u64 val, int size)
 u32 fdt_getprop_u32_default(const void *fdt, const char *path,
                                const char *prop, const u32 dflt)
 {
-       const fdt32_t *val;
        int off;
 
        off = fdt_path_offset(fdt, path);
        if (off < 0)
                return dflt;
 
-       val = fdt_getprop(fdt, off, prop, NULL);
-       if (val)
-               return fdt32_to_cpu(*val);
-       else
-               return dflt;
+       return fdt_getprop_u32_default_node(fdt, off, 0, prop, dflt);
 }
 
 /**
diff --git a/include/fdt_support.h b/include/fdt_support.h
index 9871e2f..3e1be57 100644
--- a/include/fdt_support.h
+++ b/include/fdt_support.h
@@ -12,6 +12,8 @@
 
 #include <libfdt.h>
 
+u32 fdt_getprop_u32_default_node(const void *fdt, int off, int cell,
+                               const char *prop, const u32 dflt);
 u32 fdt_getprop_u32_default(const void *fdt, const char *path,
                                const char *prop, const u32 dflt);
 int fdt_chosen(void *fdt, int force);
-- 
1.7.10.4