drm: sti: use late_register and early_unregister callbacks

Make sti driver use register callback to move debugfs
initialization out of sub-components creation.
This will allow to convert driver .load() to
drm_dev_alloc() and drm_dev_register().

sti_compositor bring up 2 crtc but only one debugfs init is
needed so use drm_crtc_index to do it on the first one.
This can't be done in sti_drv because only sti_compositor have
access to the devices.
It is almost the same for sti_encoder which handle multiple
encoder while one only debugfs entry is needed so add a boolean
to avoid multiple debugfs initialization

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1466514580-15194-3-git-send-email-benjamin.gaignard@linaro.org

drivers/gpu/drm/sti/sti_tvout.c

@@ -112,6 +112,7 @@ struct sti_tvout {
 	struct drm_encoder *hdmi;
 	struct drm_encoder *hda;
 	struct drm_encoder *dvo;
+	bool debugfs_registered;
 };
 
 struct sti_tvout_encoder {
@@ -625,8 +626,37 @@ static void sti_tvout_encoder_destroy(struct drm_encoder *encoder)
 	kfree(sti_encoder);
 }
 
+static int sti_tvout_late_register(struct drm_encoder *encoder)
+{
+	struct sti_tvout *tvout = to_sti_tvout(encoder);
+	int ret;
+
+	if (tvout->debugfs_registered)
+		return 0;
+
+	ret = tvout_debugfs_init(tvout, encoder->dev->primary);
+	if (ret)
+		return ret;
+
+	tvout->debugfs_registered = true;
+	return 0;
+}
+
+static void sti_tvout_early_unregister(struct drm_encoder *encoder)
+{
+	struct sti_tvout *tvout = to_sti_tvout(encoder);
+
+	if (!tvout->debugfs_registered)
+		return;
+
+	tvout_debugfs_exit(tvout, encoder->dev->primary);
+	tvout->debugfs_registered = false;
+}
+
 static const struct drm_encoder_funcs sti_tvout_encoder_funcs = {
 	.destroy = sti_tvout_encoder_destroy,
+	.late_register = sti_tvout_late_register,
+	.early_unregister = sti_tvout_early_unregister,
 };
 
 static void sti_dvo_encoder_enable(struct drm_encoder *encoder)
@@ -813,9 +843,6 @@ static int sti_tvout_bind(struct device *dev, struct device *master, void *data)
 
 	sti_tvout_create_encoders(drm_dev, tvout);
 
-	if (tvout_debugfs_init(tvout, drm_dev->primary))
-		DRM_ERROR("TVOUT debugfs setup failed\n");
-
 	return 0;
 }
 
@@ -823,11 +850,8 @@ static void sti_tvout_unbind(struct device *dev, struct device *master,
 	void *data)
 {
 	struct sti_tvout *tvout = dev_get_drvdata(dev);
-	struct drm_device *drm_dev = data;
 
 	sti_tvout_destroy_encoders(tvout);
-
-	tvout_debugfs_exit(tvout, drm_dev->primary);
 }
 
 static const struct component_ops sti_tvout_ops = {