dm: core: Allow device names to be freed automatically

Some devices have a name that is stored in allocated memory. At present
there is no mechanism to free this memory when the device is unbound.

Add a device flag to track whether a name is allocated and a function to
add the flag. Free the memory when the device is unbound.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c
index e1714b2..0e56b23 100644
--- a/drivers/core/device-remove.c
+++ b/drivers/core/device-remove.c
@@ -112,6 +112,8 @@
 
 	devres_release_all(dev);
 
+	if (dev->flags & DM_NAME_ALLOCED)
+		free((char *)dev->name);
 	free(dev);
 
 	return 0;
diff --git a/drivers/core/device.c b/drivers/core/device.c
index 2b12ce7..5c2dc70 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -706,12 +706,18 @@
 	return list_is_last(&dev->sibling_node, &parent->child_head);
 }
 
+void device_set_name_alloced(struct udevice *dev)
+{
+	dev->flags |= DM_NAME_ALLOCED;
+}
+
 int device_set_name(struct udevice *dev, const char *name)
 {
 	name = strdup(name);
 	if (!name)
 		return -ENOMEM;
 	dev->name = name;
+	device_set_name_alloced(dev);
 
 	return 0;
 }
diff --git a/include/dm/device.h b/include/dm/device.h
index 8970fc0..e9a8ec7 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -41,6 +41,9 @@
 /* Device is bound */
 #define DM_FLAG_BOUND			(1 << 6)
 
+/* Device name is allocated and should be freed on unbind() */
+#define DM_NAME_ALLOCED			(1 << 7)
+
 /**
  * struct udevice - An instance of a driver
  *
@@ -523,6 +526,9 @@
  * this is unnecessary but for probed devices which don't get a useful name
  * this function can be helpful.
  *
+ * The name is allocated and will be freed automatically when the device is
+ * unbound.
+ *
  * @dev:	Device to update
  * @name:	New name (this string is allocated new memory and attached to
  *		the device)
@@ -532,6 +538,16 @@
 int device_set_name(struct udevice *dev, const char *name);
 
 /**
+ * device_set_name_alloced() - note that a device name is allocated
+ *
+ * This sets the DM_NAME_ALLOCED flag for the device, so that when it is
+ * unbound the name will be freed. This avoids memory leaks.
+ *
+ * @dev:	Device to update
+ */
+void device_set_name_alloced(struct udevice *dev);
+
+/**
  * device_is_on_pci_bus - Test if a device is on a PCI bus
  *
  * @dev:	device to test