drm/ingenic: Fix driver not probing when IPU port is missing

Even if support for the IPU was compiled in, we may run on a device
(e.g. the Qi LB60) where the IPU is not available, or simply with an old
devicetree without the IPU node. In that case the ingenic-drm refused to
probe.

Fix the driver so that it will probe even if the IPU node is not present
in devicetree (but then IPU support is disabled of course).

v2: Take a different approach

Fixes: fc1acf3 ("drm/ingenic: Add support for the IPU")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200827114404.36748-2-paul@crapouillou.net

drivers/gpu/drm/ingenic/ingenic-drm-drv.c

@@ -673,7 +673,7 @@ static void ingenic_drm_unbind_all(void *d)
 	component_unbind_all(priv->dev, &priv->drm);
 }
 
-static int ingenic_drm_bind(struct device *dev)
+static int ingenic_drm_bind(struct device *dev, bool has_components)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	const struct jz_soc_info *soc_info;
@@ -808,7 +808,7 @@ static int ingenic_drm_bind(struct device *dev)
 			return ret;
 		}
 
-		if (IS_ENABLED(CONFIG_DRM_INGENIC_IPU)) {
+		if (IS_ENABLED(CONFIG_DRM_INGENIC_IPU) && has_components) {
 			ret = component_bind_all(dev, drm);
 			if (ret) {
 				if (ret != -EPROBE_DEFER)
@@ -939,6 +939,11 @@ static int ingenic_drm_bind(struct device *dev)
 	return ret;
 }
 
+static int ingenic_drm_bind_with_components(struct device *dev)
+{
+	return ingenic_drm_bind(dev, true);
+}
+
 static int compare_of(struct device *dev, void *data)
 {
 	return dev->of_node == data;
@@ -957,7 +962,7 @@ static void ingenic_drm_unbind(struct device *dev)
 }
 
 static const struct component_master_ops ingenic_master_ops = {
-	.bind = ingenic_drm_bind,
+	.bind = ingenic_drm_bind_with_components,
 	.unbind = ingenic_drm_unbind,
 };
 
@@ -968,14 +973,12 @@ static int ingenic_drm_probe(struct platform_device *pdev)
 	struct device_node *np;
 
 	if (!IS_ENABLED(CONFIG_DRM_INGENIC_IPU))
-		return ingenic_drm_bind(dev);
+		return ingenic_drm_bind(dev, false);
 
 	/* IPU is at port address 8 */
 	np = of_graph_get_remote_node(dev->of_node, 8, 0);
-	if (!np) {
-		dev_err(dev, "Unable to get IPU node\n");
-		return -EINVAL;
-	}
+	if (!np)
+		return ingenic_drm_bind(dev, false);
 
 	drm_of_component_match_add(dev, &match, compare_of, np);
 	of_node_put(np);