drm/omap: dss: Make omap_dss_get_next_device() more generic

Despite its name, the omap_dss_get_next_device() function operates on
display devices only. Make it more generic by allowing operation on all
devices, with a parameter to specify the device type.

While at it rename the function to omapdss_device_get_next() to match
the naming of the other functions operating on struct omap_dss_device.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/dss/base.c

@@ -104,6 +104,58 @@ struct omap_dss_device *omapdss_find_device_by_port(struct device_node *src,
 	return NULL;
 }
 
+/*
+ * Search for the next device starting at @from. If display_only is true, skip
+ * non-display devices. Release the reference to the @from device, and acquire
+ * a reference to the returned device if found.
+ */
+struct omap_dss_device *omapdss_device_get_next(struct omap_dss_device *from,
+						bool display_only)
+{
+	struct omap_dss_device *dssdev;
+	struct list_head *list;
+
+	mutex_lock(&omapdss_devices_lock);
+
+	if (list_empty(&omapdss_devices_list)) {
+		dssdev = NULL;
+		goto done;
+	}
+
+	/*
+	 * Start from the from entry if given or from omapdss_devices_list
+	 * otherwise.
+	 */
+	list = from ? &from->list : &omapdss_devices_list;
+
+	list_for_each_entry(dssdev, list, list) {
+		/*
+		 * Stop if we reach the omapdss_devices_list, that's the end of
+		 * the list.
+		 */
+		if (&dssdev->list == &omapdss_devices_list) {
+			dssdev = NULL;
+			goto done;
+		}
+
+		/* Filter out non-display entries if display_only is set. */
+		if (!display_only || dssdev->driver)
+			goto done;
+	}
+
+	dssdev = NULL;
+
+done:
+	if (from)
+		omap_dss_put_device(from);
+	if (dssdev)
+		omap_dss_get_device(dssdev);
+
+	mutex_unlock(&omapdss_devices_lock);
+	return dssdev;
+}
+EXPORT_SYMBOL(omapdss_device_get_next);
+
 int omapdss_device_connect(struct omap_dss_device *src,
 			   struct omap_dss_device *dst)
 {

drivers/gpu/drm/omapdrm/dss/display.c

@@ -92,52 +92,3 @@ void omap_dss_put_device(struct omap_dss_device *dssdev)
 	module_put(dssdev->owner);
 }
 EXPORT_SYMBOL(omap_dss_put_device);
-
-/*
- * ref count of the found device is incremented.
- * ref count of from-device is decremented.
- */
-struct omap_dss_device *omap_dss_get_next_device(struct omap_dss_device *from)
-{
-	struct list_head *l;
-	struct omap_dss_device *dssdev;
-
-	mutex_lock(&panel_list_mutex);
-
-	if (list_empty(&panel_list)) {
-		dssdev = NULL;
-		goto out;
-	}
-
-	if (from == NULL) {
-		dssdev = list_first_entry(&panel_list, struct omap_dss_device,
-				panel_list);
-		omap_dss_get_device(dssdev);
-		goto out;
-	}
-
-	omap_dss_put_device(from);
-
-	list_for_each(l, &panel_list) {
-		dssdev = list_entry(l, struct omap_dss_device, panel_list);
-		if (dssdev == from) {
-			if (list_is_last(l, &panel_list)) {
-				dssdev = NULL;
-				goto out;
-			}
-
-			dssdev = list_entry(l->next, struct omap_dss_device,
-					panel_list);
-			omap_dss_get_device(dssdev);
-			goto out;
-		}
-	}
-
-	WARN(1, "'from' dssdev not found\n");
-
-	dssdev = NULL;
-out:
-	mutex_unlock(&panel_list_mutex);
-	return dssdev;
-}
-EXPORT_SYMBOL(omap_dss_get_next_device);

drivers/gpu/drm/omapdrm/dss/omapdss.h

@@ -489,11 +489,15 @@ static inline bool omapdss_is_initialized(void)
 
 int omapdss_register_display(struct omap_dss_device *dssdev);
 void omapdss_unregister_display(struct omap_dss_device *dssdev);
+#define for_each_dss_display(d) \
+	while ((d = omapdss_device_get_next(d, true)) != NULL)
 
 void omapdss_device_register(struct omap_dss_device *dssdev);
 void omapdss_device_unregister(struct omap_dss_device *dssdev);
 struct omap_dss_device *omapdss_find_device_by_port(struct device_node *src,
 						    unsigned int port);
+struct omap_dss_device *omapdss_device_get_next(struct omap_dss_device *from,
+						bool display_only);
 int omapdss_device_connect(struct omap_dss_device *src,
 			   struct omap_dss_device *dst);
 void omapdss_device_disconnect(struct omap_dss_device *src,
@@ -501,8 +505,6 @@ void omapdss_device_disconnect(struct omap_dss_device *src,
 
 struct omap_dss_device *omap_dss_get_device(struct omap_dss_device *dssdev);
 void omap_dss_put_device(struct omap_dss_device *dssdev);
-#define for_each_dss_display(d) while ((d = omap_dss_get_next_device(d)) != NULL)
-struct omap_dss_device *omap_dss_get_next_device(struct omap_dss_device *from);
 
 int omap_dss_get_num_overlay_managers(void);