xen/device-tree: Add dt_property_read_u32_array helper

Based Linux commit a67e9472da423ec47a3586920b526ebaedf25fc3

Import the Linux helper of_property_read_u32_array. This function find
and read an array of 32 bit integers from a property.

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index 1693fb8e8cfce4161bd66ef66574ae256b313e80..3ffe3eb3d2b4bbeb58e5d6b61784c21ba18e5b11 100644 (file)
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -392,6 +392,36 @@ int dt_property_read_variable_u32_array(const struct dt_device_node *np,
                                         const char *propname, u32 *out_values,
                                         size_t sz_min, size_t sz_max);
 
+/**
+ * dt_property_read_u32_array - Find and read an array of 32 bit integers
+ * from a property.
+ *
+ * @np:     device node from which the property value is to be read.
+ * @propname:   name of the property to be searched.
+ * @out_values: pointer to return value, modified only if return value is 0.
+ * @sz:     number of array elements to read
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+static inline int dt_property_read_u32_array(const struct dt_device_node *np,
+                                             const char *propname,
+                                             u32 *out_values, size_t sz)
+{
+    int ret = dt_property_read_variable_u32_array(np, propname, out_values,
+                              sz, 0);
+    if ( ret >= 0 )
+        return 0;
+    else
+        return ret;
+}
+
 /**
  * dt_property_read_bool - Check if a property exists
  * @np: node to get the value