drm/ast: Move SIL164-based connector code into separate helpers

Add helpers for initializing SIL164-based connectors. These used to be
handled by the VGA connector code. But SIL164 provides output via DVI-I,
so set the encoder and connector types accordingly.

If a SIL164 chip has been detected, ast will now create a DVI-I
connector instead of a VGA connector.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220207141544.30015-10-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_drv.h

@@ -140,6 +140,17 @@ to_ast_vga_connector(struct drm_connector *connector)
 	return container_of(connector, struct ast_vga_connector, base);
 }
 
+struct ast_sil164_connector {
+	struct drm_connector base;
+	struct ast_i2c_chan *i2c;
+};
+
+static inline struct ast_sil164_connector *
+to_ast_sil164_connector(struct drm_connector *connector)
+{
+	return container_of(connector, struct ast_sil164_connector, base);
+}
+
 /*
  * Device
  */
@@ -165,6 +176,10 @@ struct ast_private {
 			struct drm_encoder encoder;
 			struct ast_vga_connector vga_connector;
 		} vga;
+		struct {
+			struct drm_encoder encoder;
+			struct ast_sil164_connector sil164_connector;
+		} sil164;
 		struct {
 			struct drm_encoder encoder;
 			struct drm_connector connector;

drivers/gpu/drm/ast/ast_mode.c

@@ -1347,6 +1347,100 @@ static int ast_vga_output_init(struct ast_private *ast)
 	return 0;
 }
 
+/*
+ * SIL164 Connector
+ */
+
+static int ast_sil164_connector_helper_get_modes(struct drm_connector *connector)
+{
+	struct ast_sil164_connector *ast_sil164_connector = to_ast_sil164_connector(connector);
+	struct edid *edid;
+	int count;
+
+	if (!ast_sil164_connector->i2c)
+		goto err_drm_connector_update_edid_property;
+
+	edid = drm_get_edid(connector, &ast_sil164_connector->i2c->adapter);
+	if (!edid)
+		goto err_drm_connector_update_edid_property;
+
+	count = drm_add_edid_modes(connector, edid);
+	kfree(edid);
+
+	return count;
+
+err_drm_connector_update_edid_property:
+	drm_connector_update_edid_property(connector, NULL);
+	return 0;
+}
+
+static const struct drm_connector_helper_funcs ast_sil164_connector_helper_funcs = {
+	.get_modes = ast_sil164_connector_helper_get_modes,
+};
+
+static const struct drm_connector_funcs ast_sil164_connector_funcs = {
+	.reset = drm_atomic_helper_connector_reset,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = drm_connector_cleanup,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int ast_sil164_connector_init(struct drm_device *dev,
+				     struct ast_sil164_connector *ast_sil164_connector)
+{
+	struct drm_connector *connector = &ast_sil164_connector->base;
+	int ret;
+
+	ast_sil164_connector->i2c = ast_i2c_create(dev);
+	if (!ast_sil164_connector->i2c)
+		drm_err(dev, "failed to add ddc bus for connector\n");
+
+	if (ast_sil164_connector->i2c)
+		ret = drm_connector_init_with_ddc(dev, connector, &ast_sil164_connector_funcs,
+						  DRM_MODE_CONNECTOR_DVII,
+						  &ast_sil164_connector->i2c->adapter);
+	else
+		ret = drm_connector_init(dev, connector, &ast_sil164_connector_funcs,
+					 DRM_MODE_CONNECTOR_DVII);
+	if (ret)
+		return ret;
+
+	drm_connector_helper_add(connector, &ast_sil164_connector_helper_funcs);
+
+	connector->interlace_allowed = 0;
+	connector->doublescan_allowed = 0;
+
+	connector->polled = DRM_CONNECTOR_POLL_CONNECT;
+
+	return 0;
+}
+
+static int ast_sil164_output_init(struct ast_private *ast)
+{
+	struct drm_device *dev = &ast->base;
+	struct drm_crtc *crtc = &ast->crtc;
+	struct drm_encoder *encoder = &ast->output.sil164.encoder;
+	struct ast_sil164_connector *ast_sil164_connector = &ast->output.sil164.sil164_connector;
+	struct drm_connector *connector = &ast_sil164_connector->base;
+	int ret;
+
+	ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_TMDS);
+	if (ret)
+		return ret;
+	encoder->possible_crtcs = drm_crtc_mask(crtc);
+
+	ret = ast_sil164_connector_init(dev, ast_sil164_connector);
+	if (ret)
+		return ret;
+
+	ret = drm_connector_attach_encoder(connector, encoder);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 /*
  * DP501 Connector
  */
@@ -1492,14 +1586,15 @@ int ast_mode_config_init(struct ast_private *ast)
 
 	switch (ast->tx_chip_type) {
 	case AST_TX_NONE:
-	case AST_TX_SIL164:
 		ret = ast_vga_output_init(ast);
 		break;
+	case AST_TX_SIL164:
+		ret = ast_sil164_output_init(ast);
+		break;
 	case AST_TX_DP501:
 		ret = ast_dp501_output_init(ast);
 		break;
 	}
-
 	if (ret)
 		return ret;