drm/hisilicon: Features to support reading resolutions from EDID

Use drm_get_edid to get the resolution, if that fails, set it to
a fixed resolution. Rewrite the desrtoy callback function to release
resources.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/1600778670-60370-3-git-send-email-tiantao6@hisilicon.com

drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_vdac.c

@@ -21,12 +21,24 @@
 static int hibmc_connector_get_modes(struct drm_connector *connector)
 {
 	int count;
+	void *edid;
+	struct hibmc_connector *hibmc_connector = to_hibmc_connector(connector);
+
+	edid = drm_get_edid(connector, &hibmc_connector->adapter);
+	if (edid) {
+		drm_connector_update_edid_property(connector, edid);
+		count = drm_add_edid_modes(connector, edid);
+		if (count)
+			goto out;
+	}
 
 	count = drm_add_modes_noedid(connector,
 				     connector->dev->mode_config.max_width,
 				     connector->dev->mode_config.max_height);
 	drm_set_preferred_mode(connector, 1024, 768);
 
+out:
+	kfree(edid);
 	return count;
 }
 
@@ -36,6 +48,14 @@ static enum drm_mode_status hibmc_connector_mode_valid(struct drm_connector *con
 	return MODE_OK;
 }
 
+static void hibmc_connector_destroy(struct drm_connector *connector)
+{
+	struct hibmc_connector *hibmc_connector = to_hibmc_connector(connector);
+
+	i2c_del_adapter(&hibmc_connector->adapter);
+	drm_connector_cleanup(connector);
+}
+
 static const struct drm_connector_helper_funcs
 	hibmc_connector_helper_funcs = {
 	.get_modes = hibmc_connector_get_modes,
@@ -44,7 +64,7 @@ static const struct drm_connector_helper_funcs
 
 static const struct drm_connector_funcs hibmc_connector_funcs = {
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = drm_connector_cleanup,
+	.destroy = hibmc_connector_destroy,
 	.reset = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
@@ -77,10 +97,17 @@ static const struct drm_encoder_funcs hibmc_encoder_funcs = {
 int hibmc_vdac_init(struct hibmc_drm_private *priv)
 {
 	struct drm_device *dev = priv->dev;
+	struct hibmc_connector *hibmc_connector = &priv->connector;
 	struct drm_encoder *encoder = &priv->encoder;
-	struct drm_connector *connector = &priv->connector;
+	struct drm_connector *connector = &hibmc_connector->base;
 	int ret;
 
+	ret = hibmc_ddc_create(dev, hibmc_connector);
+	if (ret) {
+		drm_err(dev, "failed to create ddc: %d\n", ret);
+		return ret;
+	}
+
 	encoder->possible_crtcs = 0x1;
 	ret = drm_encoder_init(dev, encoder, &hibmc_encoder_funcs,
 			       DRM_MODE_ENCODER_DAC, NULL);
@@ -91,12 +118,15 @@ int hibmc_vdac_init(struct hibmc_drm_private *priv)
 
 	drm_encoder_helper_add(encoder, &hibmc_encoder_helper_funcs);
 
-	ret = drm_connector_init(dev, connector, &hibmc_connector_funcs,
-				 DRM_MODE_CONNECTOR_VGA);
+	ret = drm_connector_init_with_ddc(dev, connector,
+					  &hibmc_connector_funcs,
+					  DRM_MODE_CONNECTOR_VGA,
+					  &hibmc_connector->adapter);
 	if (ret) {
 		drm_err(dev, "failed to init connector: %d\n", ret);
 		return ret;
 	}
+
 	drm_connector_helper_add(connector, &hibmc_connector_helper_funcs);
 
 	drm_connector_attach_encoder(connector, encoder);