[RFC PATCH 2/4] drm/panel: add interface tracker support

[Andrzej Hajda]

drm_panel framework allows only query for presence of given panel.
It also does not protect panel module from unloading and does not
provide solution for driver unbinding. interface_tracker
should solve both issues.

Signed-off-by: Andrzej Hajda <a.hajda at samsung.com>
---
---
 drivers/gpu/drm/drm_panel.c       | 5 +++++
 include/linux/interface_tracker.h | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index 2ef988e..72a3c5c 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -22,6 +22,7 @@
  */
 
 #include <linux/err.h>
+#include <linux/interface_tracker.h>
 #include <linux/module.h>
 
 #include <drm/drm_crtc.h>
@@ -41,6 +42,8 @@ int drm_panel_add(struct drm_panel *panel)
 	mutex_lock(&panel_lock);
 	list_add_tail(&panel->list, &panel_list);
 	mutex_unlock(&panel_lock);
+	interface_tracker_ifup(panel->dev->of_node,
+			       INTERFACE_TRACKER_TYPE_DRM_PANEL, panel);
 
 	return 0;
 }
@@ -48,6 +51,8 @@ EXPORT_SYMBOL(drm_panel_add);
 
 void drm_panel_remove(struct drm_panel *panel)
 {
+	interface_tracker_ifdown(panel->dev->of_node,
+				 INTERFACE_TRACKER_TYPE_DRM_PANEL, panel);
 	mutex_lock(&panel_lock);
 	list_del_init(&panel->list);
 	mutex_unlock(&panel_lock);
diff --git a/include/linux/interface_tracker.h b/include/linux/interface_tracker.h
index e1eff00..0a08cba 100644
--- a/include/linux/interface_tracker.h
+++ b/include/linux/interface_tracker.h
@@ -6,6 +6,8 @@
 struct list_head;
 struct interface_tracker_block;
 
+#define INTERFACE_TRACKER_TYPE_DRM_PANEL 1
+
 typedef void (*interface_tracker_fn_t)(struct interface_tracker_block *itb,
 				       const void *object, unsigned long type,
 				       bool on, void *data);
-- 
1.8.3.2