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
diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index 36d9d66..9d9c2c5 100644
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -1007,8 +1007,21 @@
 	return -EINVAL;
 }
 
+static int sti_hdmi_late_register(struct drm_connector *connector)
+{
+	struct sti_hdmi_connector *hdmi_connector
+		= to_sti_hdmi_connector(connector);
+	struct sti_hdmi *hdmi = hdmi_connector->hdmi;
+
+	if (hdmi_debugfs_init(hdmi, hdmi->drm_dev->primary)) {
+		DRM_ERROR("HDMI debugfs setup failed\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static const struct drm_connector_funcs sti_hdmi_connector_funcs = {
-	.dpms = drm_atomic_helper_connector_dpms,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.detect = sti_hdmi_connector_detect,
 	.destroy = sti_hdmi_connector_destroy,
@@ -1018,6 +1031,7 @@
 	.atomic_get_property = sti_hdmi_connector_get_property,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+	.late_register = sti_hdmi_late_register,
 };
 
 static struct drm_encoder *sti_hdmi_find_encoder(struct drm_device *dev)
@@ -1091,9 +1105,6 @@
 	/* Enable default interrupts */
 	hdmi_write(hdmi, HDMI_DEFAULT_INT, HDMI_INT_EN);
 
-	if (hdmi_debugfs_init(hdmi, drm_dev->primary))
-		DRM_ERROR("HDMI debugfs setup failed\n");
-
 	return 0;
 
 err_sysfs: