drm/omap: Refactor initialization sequence

The omapdrm driver initialization procedure starts by connecting all
available pipelines, gathering related information (such as output and
display DSS devices, and DT aliases), sorting them by alias, and finally
creates all the DRM/KMS objects.

When using DRM bridges instead of DSS devices, we will need to attach to
the bridges before getting the aliases. As attaching to bridges requires
an encoder object, we have to reorganize the initialization sequence to
create encoders before getting aliases and sorting the pipelines.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -150,48 +150,27 @@ static void omap_disconnect_pipelines(struct drm_device *ddev)
 	priv->num_pipes = 0;
 }
 
-static int omap_compare_pipes(const void *a, const void *b)
-{
-	const struct omap_drm_pipeline *pipe1 = a;
-	const struct omap_drm_pipeline *pipe2 = b;
-
-	if (pipe1->alias_id > pipe2->alias_id)
-		return 1;
-	else if (pipe1->alias_id < pipe2->alias_id)
-		return -1;
-	return 0;
-}
-
 static int omap_connect_pipelines(struct drm_device *ddev)
 {
 	struct omap_drm_private *priv = ddev->dev_private;
 	struct omap_dss_device *output = NULL;
-	unsigned int i;
 	int r;
 
-	if (!omapdss_stack_is_ready())
-		return -EPROBE_DEFER;
-
 	for_each_dss_output(output) {
 		r = omapdss_device_connect(priv->dss, NULL, output);
 		if (r == -EPROBE_DEFER) {
 			omapdss_device_put(output);
-			goto cleanup;
+			return r;
 		} else if (r) {
 			dev_warn(output->dev, "could not connect output %s\n",
 				 output->name);
 		} else {
 			struct omap_drm_pipeline *pipe;
-			int id;
 
 			pipe = &priv->pipes[priv->num_pipes++];
 			pipe->output = omapdss_device_get(output);
 			pipe->display = omapdss_display_get(output);
 
-			id = of_alias_get_id(pipe->display->dev->of_node,
-					     "display");
-			pipe->alias_id = id >= 0 ? id : priv->num_pipes - 1;
-
 			if (priv->num_pipes == ARRAY_SIZE(priv->pipes)) {
 				/* To balance the 'for_each_dss_output' loop */
 				omapdss_device_put(output);
@@ -200,36 +179,19 @@ static int omap_connect_pipelines(struct drm_device *ddev)
 		}
 	}
 
-	/* Sort the list by DT aliases */
-	sort(priv->pipes, priv->num_pipes, sizeof(priv->pipes[0]),
-	     omap_compare_pipes, NULL);
-
-	/*
-	 * Populate the pipeline lookup table by DISPC channel. Only one display
-	 * is allowed per channel.
-	 */
-	for (i = 0; i < priv->num_pipes; ++i) {
-		struct omap_drm_pipeline *pipe = &priv->pipes[i];
-		enum omap_channel channel = pipe->output->dispc_channel;
-
-		if (WARN_ON(priv->channels[channel] != NULL)) {
-			r = -EINVAL;
-			goto cleanup;
-		}
-
-		priv->channels[channel] = pipe;
-	}
-
 	return 0;
+}
 
-cleanup:
-	/*
-	 * if we are deferring probe, we disconnect the devices we previously
-	 * connected
-	 */
-	omap_disconnect_pipelines(ddev);
+static int omap_compare_pipelines(const void *a, const void *b)
+{
+	const struct omap_drm_pipeline *pipe1 = a;
+	const struct omap_drm_pipeline *pipe2 = b;
 
-	return r;
+	if (pipe1->alias_id > pipe2->alias_id)
+		return 1;
+	else if (pipe1->alias_id < pipe2->alias_id)
+		return -1;
+	return 0;
 }
 
 static int omap_modeset_init_properties(struct drm_device *dev)
@@ -254,6 +216,9 @@ static int omap_modeset_init(struct drm_device *dev)
 	int ret;
 	u32 plane_crtc_mask;
 
+	if (!omapdss_stack_is_ready())
+		return -EPROBE_DEFER;
+
 	drm_mode_config_init(dev);
 
 	ret = omap_modeset_init_properties(dev);
@@ -268,6 +233,10 @@ static int omap_modeset_init(struct drm_device *dev)
 	 * configuration does not match the expectations or exceeds
 	 * the available resources, the configuration is rejected.
 	 */
+	ret = omap_connect_pipelines(dev);
+	if (ret < 0)
+		return ret;
+
 	if (priv->num_pipes > num_mgrs || priv->num_pipes > num_ovls) {
 		dev_err(dev->dev, "%s(): Too many connected displays\n",
 			__func__);
@@ -293,33 +262,58 @@ static int omap_modeset_init(struct drm_device *dev)
 		priv->planes[priv->num_planes++] = plane;
 	}
 
-	/* Create the CRTCs, encoders and connectors. */
+	/* Create the encoders and get the pipelines aliases. */
 	for (i = 0; i < priv->num_pipes; i++) {
 		struct omap_drm_pipeline *pipe = &priv->pipes[i];
-		struct omap_dss_device *display = pipe->display;
-		struct drm_connector *connector;
-		struct drm_encoder *encoder;
-		struct drm_crtc *crtc;
+		int id;
 
-		encoder = omap_encoder_init(dev, pipe->output);
-		if (!encoder)
+		pipe->encoder = omap_encoder_init(dev, pipe->output);
+		if (!pipe->encoder)
 			return -ENOMEM;
 
-		connector = omap_connector_init(dev, pipe->output, display,
-						encoder);
+		id = of_alias_get_id(pipe->display->dev->of_node, "display");
+		pipe->alias_id = id >= 0 ? id : i;
+	}
+
+	/* Sort the pipelines by DT aliases. */
+	sort(priv->pipes, priv->num_pipes, sizeof(priv->pipes[0]),
+	     omap_compare_pipelines, NULL);
+
+	/*
+	 * Populate the pipeline lookup table by DISPC channel. Only one display
+	 * is allowed per channel.
+	 */
+	for (i = 0; i < priv->num_pipes; ++i) {
+		struct omap_drm_pipeline *pipe = &priv->pipes[i];
+		enum omap_channel channel = pipe->output->dispc_channel;
+
+		if (WARN_ON(priv->channels[channel] != NULL))
+			return -EINVAL;
+
+		priv->channels[channel] = pipe;
+	}
+
+	/* Create the connectors and CRTCs. */
+	for (i = 0; i < priv->num_pipes; i++) {
+		struct omap_drm_pipeline *pipe = &priv->pipes[i];
+		struct drm_encoder *encoder = pipe->encoder;
+		struct drm_connector *connector;
+		struct drm_crtc *crtc;
+
+		connector = omap_connector_init(dev, pipe->output,
+						pipe->display, encoder);
 		if (!connector)
 			return -ENOMEM;
 
+		drm_connector_attach_encoder(connector, encoder);
+		pipe->connector = connector;
+
 		crtc = omap_crtc_init(dev, pipe, priv->planes[i]);
 		if (IS_ERR(crtc))
 			return PTR_ERR(crtc);
 
-		drm_connector_attach_encoder(connector, encoder);
 		encoder->possible_crtcs = 1 << i;
-
 		pipe->crtc = crtc;
-		pipe->encoder = encoder;
-		pipe->connector = connector;
 	}
 
 	DBG("registered %u planes, %u crtcs/encoders/connectors\n",
@@ -556,10 +550,6 @@ static int omapdrm_init(struct omap_drm_private *priv, struct device *dev)
 
 	omap_crtc_pre_init(priv);
 
-	ret = omap_connect_pipelines(ddev);
-	if (ret)
-		goto err_crtc_uninit;
-
 	soc = soc_device_match(omapdrm_soc_devices);
 	priv->omaprev = soc ? (unsigned int)soc->data : 0;
 	priv->wq = alloc_ordered_workqueue("omapdrm", 0);
@@ -617,7 +607,6 @@ static int omapdrm_init(struct omap_drm_private *priv, struct device *dev)
 	omap_gem_deinit(ddev);
 	destroy_workqueue(priv->wq);
 	omap_disconnect_pipelines(ddev);
-err_crtc_uninit:
 	omap_crtc_pre_uninit(priv);
 	drm_dev_put(ddev);
 	return ret;