dm: core: Add ofnode function to read a 64-bit int

We have a 32-bit version of this function. Add a 64-bit version as well so
we can easily read 64-bit ints from the device tree.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/core/of_access.c

@@ -457,6 +457,26 @@ int of_read_u32_array(const struct device_node *np, const char *propname,
 	return 0;
 }
 
+int of_read_u64(const struct device_node *np, const char *propname, u64 *outp)
+{
+	const __be64 *val;
+
+	debug("%s: %s: ", __func__, propname);
+	if (!np)
+		return -EINVAL;
+	val = of_find_property_value_of_size(np, propname, sizeof(*outp));
+	if (IS_ERR(val)) {
+		debug("(not found)\n");
+		return PTR_ERR(val);
+	}
+
+	*outp = be64_to_cpup(val);
+	debug("%#llx (%lld)\n", (unsigned long long)*outp,
+              (unsigned long long)*outp);
+
+	return 0;
+}
+
 int of_property_match_string(const struct device_node *np, const char *propname,
 			     const char *string)
 {

drivers/core/ofnode.c

@@ -55,6 +55,38 @@ int ofnode_read_s32_default(ofnode node, const char *propname, s32 def)
 	return def;
 }
 
+int ofnode_read_u64(ofnode node, const char *propname, u64 *outp)
+{
+	const fdt64_t *cell;
+	int len;
+
+	assert(ofnode_valid(node));
+	debug("%s: %s: ", __func__, propname);
+
+	if (ofnode_is_np(node))
+		return of_read_u64(ofnode_to_np(node), propname, outp);
+
+	cell = fdt_getprop(gd->fdt_blob, ofnode_to_offset(node), propname,
+			   &len);
+	if (!cell || len < sizeof(*cell)) {
+		debug("(not found)\n");
+		return -EINVAL;
+	}
+	*outp = fdt64_to_cpu(cell[0]);
+	debug("%#llx (%lld)\n", (unsigned long long)*outp,
+	      (unsigned long long)*outp);
+
+	return 0;
+}
+
+int ofnode_read_u64_default(ofnode node, const char *propname, u64 def)
+{
+	assert(ofnode_valid(node));
+	ofnode_read_u64(node, propname, &def);
+
+	return def;
+}
+
 bool ofnode_read_bool(ofnode node, const char *propname)
 {
 	const void *prop;

include/dm/of_access.h

@@ -218,6 +218,22 @@ struct device_node *of_find_node_by_phandle(phandle handle);
  */
 int of_read_u32(const struct device_node *np, const char *propname, u32 *outp);
 
+/**
+ * of_read_u64() - Find and read a 64-bit integer from a property
+ *
+ * Search for a property in a device node and read a 64-bit value from
+ * it.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @outp:	pointer to return value, modified only if return value is 0.
+ *
+ * @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.
+ */
+int of_read_u64(const struct device_node *np, const char *propname, u64 *outp);
+
 /**
  * of_read_u32_array() - Find and read an array of 32 bit integers
  *

include/dm/ofnode.h

@@ -236,6 +236,16 @@ int ofnode_read_u32_default(ofnode ref, const char *propname, u32 def);
  */
 int ofnode_read_s32_default(ofnode node, const char *propname, s32 def);
 
+/**
+ * ofnode_read_u64_default() - Read a 64-bit integer from a property
+ *
+ * @ref:	valid node reference to read 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
+ */
+int ofnode_read_u64_default(ofnode node, const char *propname, u64 def);
+
 /**
  * ofnode_read_string() - Read a string from a property
  *