[U-Boot] [PATCH v2 1/4] core: Add functions to set properties in live-tree

[Mario Six]

Implement a set of functions to manipulate properties in a live device
tree:

* ofnode_set_property() to set generic properties of a node
* ofnode_write_string() to set string properties of a node
* ofnode_set_enabled() to either enable or disable a node

Signed-off-by: Mario Six <mario.six at gdsys.cc>

---

v1 -> v2:
* Fix potential NULL pointer dereference in ofnode_write_property

---
 drivers/core/ofnode.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++
 include/dm/ofnode.h   | 37 ++++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)

diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index 5909a25f85..a55aa75e5b 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -687,3 +687,61 @@ u64 ofnode_translate_address(ofnode node, const fdt32_t *in_addr)
 	else
 		return fdt_translate_address(gd->fdt_blob, ofnode_to_offset(node), in_addr);
 }
+
+#ifdef CONFIG_OF_LIVE
+int ofnode_write_property(ofnode node, const char *propname, int len,
+			  const void *value)
+{
+	const struct device_node *np = ofnode_to_np(node);
+	struct property *pp;
+	struct property *pp_last = NULL;
+	struct property *new;
+
+	if (!np)
+		return -EINVAL;
+
+	for (pp = np->properties; pp; pp = pp->next) {
+		if (strcmp(pp->name, propname) == 0) {
+			/* Property exists -> change value */
+			pp->value = (void *)value;
+			pp->length = len;
+			return 0;
+		}
+		pp_last = pp;
+	}
+
+	if (!pp_last)
+		return -ENOENT;
+
+	/* Property does not exist -> append new property */
+	new = malloc(sizeof(struct property));
+
+	new->name = strdup(propname);
+	new->value = malloc(len);
+	memcpy(new->value, value, len);
+	new->length = len;
+	new->next = NULL;
+
+	pp_last->next = new;
+
+	return 0;
+}
+
+int ofnode_write_string(ofnode node, const char *propname, const char *value)
+{
+	assert(ofnode_valid(node));
+	debug("%s: %s = %s", __func__, propname, value);
+
+	return ofnode_write_property(node, propname, strlen(value) + 1, value);
+}
+
+int ofnode_set_enabled(ofnode node, bool value)
+{
+	assert(ofnode_valid(node));
+
+	if (value)
+		return ofnode_write_string(node, "status", "okay");
+	else
+		return ofnode_write_string(node, "status", "disable");
+}
+#endif
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index 0d008404f9..9224d583fc 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -681,4 +681,41 @@ int ofnode_read_resource_byname(ofnode node, const char *name,
  * @return the translated address; OF_BAD_ADDR on error
  */
 u64 ofnode_translate_address(ofnode node, const fdt32_t *in_addr);
+
+/**
+ * ofnode_write_property() - Set a property of a ofnode
+ *
+ * @node:	The node for whose property should be set
+ * @propname:	The name of the property to set
+ * @len:	The length of the new value of the property
+ * @value:	The new value of the property
+ * @return 0 if successful, -ve on error
+ */
+int ofnode_write_property(ofnode node, const char *propname, int len,
+			  const void *value);
+
+/**
+ * ofnode_write_string() - Set a string property of a ofnode
+ *
+ * @node:	The node for whose string property should be set
+ * @propname:	The name of the string property to set
+ * @value:	The new value of the string property
+ * @return 0 if successful, -ve on error
+ */
+int ofnode_write_string(ofnode node, const char *propname, const char *value);
+
+/**
+ * ofnode_set_enabled() - Enable or disable a device tree node given by its ofnode
+ *
+ * This function effectively sets the node's "status" property to either "okay"
+ * or "disable", hence making it available for driver model initialization or
+ * not.
+ *
+ * @node:	The node to enable
+ * @value:	Flag that tells the function to either disable or enable the
+ *		node
+ * @return 0 if successful, -ve on error
+ */
+int ofnode_set_enabled(ofnode node, bool value);
+
 #endif
--
2.16.1