dm: core: Support accessing core tags

At present tag numbers are only allocated for non-core data, meaning that
the 'core' data, like priv and plat, are accessed through dedicated
functions.

For debugging and consistency it is convenient to use tags for this 'core'
data too. Add support for this, with new tag numbers and functions to
access the pointer and size for each.

Update one of the test drivers so that the uclass-private data can be
tested here.

There is some code duplication with functions like device_alloc_priv() but
this is not addressed for now. At some point, some rationalisation may
help to reduce code size, but more thought it needed on that.

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

2 files changed, 37 insertions, 1 deletions

diff --git a/include/dm/device.h b/include/dm/device.h
index 5bdb10653f8..12c6ba37ff3 100644
--- a/include/dm/device.h
+++ b/include/dm/device.h
@@ -11,6 +11,7 @@
 #define _DM_DEVICE_H
 
 #include <dm/ofnode.h>
+#include <dm/tag.h>
 #include <dm/uclass-id.h>
 #include <fdtdec.h>
 #include <linker_lists.h>
@@ -547,6 +548,30 @@ void *dev_get_parent_priv(const struct udevice *dev);
 void *dev_get_uclass_priv(const struct udevice *dev);
 
 /**
+ * dev_get_attach_ptr() - Get the value of an attached pointed tag
+ *
+ * The tag is assumed to hold a pointer, if it exists
+ *
+ * @dev: Device to look at
+ * @tag: Tag to access
+ * @return value of tag, or NULL if there is no tag of this type
+ */
+void *dev_get_attach_ptr(const struct udevice *dev, enum dm_tag_t tag);
+
+/**
+ * dev_get_attach_size() - Get the size of an attached tag
+ *
+ * Core tags have an automatic-allocation mechanism where the allocated size is
+ * defined by the device, parent or uclass. This returns the size associated
+ * with a particular tag
+ *
+ * @dev: Device to look at
+ * @tag: Tag to access
+ * @return size of auto-allocated data, 0 if none
+ */
+int dev_get_attach_size(const struct udevice *dev, enum dm_tag_t tag);
+
+/**
  * dev_get_parent() - Get the parent of a device
  *
  * @child:	Child to check
diff --git a/include/dm/tag.h b/include/dm/tag.h
index 54fc31eb153..9cb5d68f0a3 100644
--- a/include/dm/tag.h
+++ b/include/dm/tag.h
@@ -13,8 +13,19 @@
 struct udevice;
 
 enum dm_tag_t {
+	/* Types of core tags that can be attached to devices */
+	DM_TAG_PLAT,
+	DM_TAG_PARENT_PLAT,
+	DM_TAG_UC_PLAT,
+
+	DM_TAG_PRIV,
+	DM_TAG_PARENT_PRIV,
+	DM_TAG_UC_PRIV,
+	DM_TAG_DRIVER_DATA,
+	DM_TAG_ATTACH_COUNT,
+
 	/* EFI_LOADER */
-	DM_TAG_EFI = 0,
+	DM_TAG_EFI = DM_TAG_ATTACH_COUNT,
 
 	DM_TAG_COUNT,
 };