OMAPDSS: add helpers to get mgr or output from display

Add two helper functions that can be used to find either the DSS output
or the overlay manager that is connected to the given display.

This hides how the output and the manager are actually connected, making
it easier to change the connections in the future.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -247,6 +247,9 @@ static int omap_modeset_init(struct drm_device *dev)
 		struct drm_encoder *encoder = priv->encoders[i];
 		struct omap_dss_device *dssdev =
 					omap_encoder_get_dssdev(encoder);
+		struct omap_dss_output *output;
+
+		output = omapdss_find_output_from_display(dssdev);
 
 		/* figure out which crtc's we can connect the encoder to: */
 		encoder->possible_crtcs = 0;
@@ -259,7 +262,7 @@ static int omap_modeset_init(struct drm_device *dev)
 			supported_outputs =
 				dss_feat_get_supported_outputs(crtc_channel);
 
-			if (supported_outputs & dssdev->output->id)
+			if (supported_outputs & output->id)
 				encoder->possible_crtcs |= (1 << id);
 		}
 	}

drivers/video/omap2/dss/manager-sysfs.c

@@ -78,7 +78,9 @@ static ssize_t manager_display_store(struct omap_overlay_manager *mgr,
 	}
 
 	if (dssdev) {
-		struct omap_dss_output *out = dssdev->output;
+		struct omap_dss_output *out;
+
+		out = omapdss_find_output_from_display(dssdev);
 
 		/*
 		 * a registered device should have an output connected to it

drivers/video/omap2/dss/output.c

@@ -141,6 +141,25 @@ struct omap_dss_output *omap_dss_find_output_by_node(struct device_node *node)
 }
 EXPORT_SYMBOL(omap_dss_find_output_by_node);
 
+struct omap_dss_output *omapdss_find_output_from_display(struct omap_dss_device *dssdev)
+{
+	return dssdev->output;
+}
+EXPORT_SYMBOL(omapdss_find_output_from_display);
+
+struct omap_overlay_manager *omapdss_find_mgr_from_display(struct omap_dss_device *dssdev)
+{
+	struct omap_dss_output *out;
+
+	out = omapdss_find_output_from_display(dssdev);
+
+	if (out == NULL)
+		return NULL;
+
+	return out->manager;
+}
+EXPORT_SYMBOL(omapdss_find_mgr_from_display);
+
 static const struct dss_mgr_ops *dss_mgr_ops;
 
 int dss_install_mgr_ops(const struct dss_mgr_ops *mgr_ops)

drivers/video/omap2/omapfb/omapfb-ioctl.c

@@ -770,12 +770,17 @@ int omapfb_ioctl(struct fb_info *fbi, unsigned int cmd, unsigned long arg)
 
 	case OMAPFB_WAITFORVSYNC:
 		DBG("ioctl WAITFORVSYNC\n");
-		if (!display || !display->output || !display->output->manager) {
+
+		if (!display) {
 			r = -EINVAL;
 			break;
 		}
 
-		mgr = display->output->manager;
+		mgr = omapdss_find_mgr_from_display(display);
+		if (!mgr) {
+			r = -EINVAL;
+			break;
+		}
 
 		r = mgr->wait_for_vsync(mgr);
 		break;

drivers/video/omap2/omapfb/omapfb-main.c

@@ -2363,18 +2363,16 @@ static int omapfb_init_connections(struct omapfb2_device *fbdev,
 	int i, r;
 	struct omap_overlay_manager *mgr;
 
-	if (!def_dssdev->output) {
-		dev_err(fbdev->dev, "no output for the default display\n");
-		return -EINVAL;
-	}
-
 	for (i = 0; i < fbdev->num_displays; ++i) {
 		struct omap_dss_device *dssdev = fbdev->displays[i].dssdev;
-		struct omap_dss_output *out = dssdev->output;
+		struct omap_dss_output *out;
 
-		mgr = omap_dss_get_overlay_manager(out->dispc_channel);
+		out = omapdss_find_output_from_display(dssdev);
+		if (!out)
+			continue;
 
-		if (!mgr || !out)
+		mgr = omap_dss_get_overlay_manager(out->dispc_channel);
+		if (!mgr)
 			continue;
 
 		if (mgr->output)
@@ -2383,7 +2381,7 @@ static int omapfb_init_connections(struct omapfb2_device *fbdev,
 		mgr->set_output(mgr, out);
 	}
 
-	mgr = def_dssdev->output->manager;
+	mgr = omapdss_find_mgr_from_display(def_dssdev);
 
 	if (!mgr) {
 		dev_err(fbdev->dev, "no ovl manager for the default display\n");

include/video/omapdss.h

@@ -786,6 +786,9 @@ int omapdss_output_set_device(struct omap_dss_output *out,
 		struct omap_dss_device *dssdev);
 int omapdss_output_unset_device(struct omap_dss_output *out);
 
+struct omap_dss_output *omapdss_find_output_from_display(struct omap_dss_device *dssdev);
+struct omap_overlay_manager *omapdss_find_mgr_from_display(struct omap_dss_device *dssdev);
+
 void omapdss_default_get_resolution(struct omap_dss_device *dssdev,
 		u16 *xres, u16 *yres);
 int omapdss_default_get_recommended_bpp(struct omap_dss_device *dssdev);