dm: core: Add functions to read 64-bit dt properties

This patch adds functions dev_read_u64_default & dev_read_u64
to read unsigned 64-bit values from devicetree.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/dm/read.h b/include/dm/read.h
index 0c62d62..803daf7 100644
--- a/include/dm/read.h
+++ b/include/dm/read.h
@@ -44,6 +44,7 @@
 }
 
 #ifndef CONFIG_DM_DEV_READ_INLINE
+
 /**
  * dev_read_u32() - read a 32-bit integer from a device's DT property
  *
@@ -97,6 +98,26 @@
 int dev_read_u32u(struct udevice *dev, const char *propname, uint *outp);
 
 /**
+ * dev_read_u64() - read a 64-bit integer from a device's DT property
+ *
+ * @dev:        device to read DT property from
+ * @propname:   name of the property to read from
+ * @outp:       place to put value (if found)
+ * @return 0 if OK, -ve on error
+ */
+int dev_read_u64(struct udevice *dev, const char *propname, u64 *outp);
+
+/**
+ * dev_read_u64_default() - read a 64-bit integer from a device's DT property
+ *
+ * @dev:        device to read DT property from
+ * @propname:   name of the property to read from
+ * @def:        default value to return if the property has no value
+ * @return property value, or @def if not found
+ */
+u64 dev_read_u64_default(struct udevice *dev, const char *propname, u64 def);
+
+/**
  * dev_read_string() - Read a string from a device's DT property
  *
  * @dev:	device to read DT property from
@@ -601,6 +622,18 @@
 	return 0;
 }
 
+static inline int dev_read_u64(struct udevice *dev,
+			       const char *propname, u64 *outp)
+{
+	return ofnode_read_u64(dev_ofnode(dev), propname, outp);
+}
+
+static inline u64 dev_read_u64_default(struct udevice *dev,
+				       const char *propname, u64 def)
+{
+	return ofnode_read_u64_default(dev_ofnode(dev), propname, def);
+}
+
 static inline const char *dev_read_string(struct udevice *dev,
 					  const char *propname)
 {