drm/bridge: tc358767: Move (e)DP bridge endpoint parsing into dedicated function

The TC358767/TC358867/TC9595 are all capable of operating in multiple
modes, DPI-to-(e)DP, DSI-to-(e)DP, DSI-to-DPI. Only the first mode is
currently supported. In order to support the rest of the modes without
making the tc_probe() overly long, split the bridge endpoint parsing
into dedicated function, where the necessary logic to detect the bridge
mode based on which endpoints are connected, can be implemented.
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de> # In both DPI to eDP and DSI to DPI mode.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220329085015.39159-7-marex@denx.de

drivers/gpu/drm/bridge/tc358767.c

@@ -1583,19 +1583,12 @@ static irqreturn_t tc_irq_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
+static int tc_probe_edp_bridge_endpoint(struct tc_data *tc)
 {
-	struct device *dev = &client->dev;
+	struct device *dev = tc->dev;
 	struct drm_panel *panel;
-	struct tc_data *tc;
 	int ret;
 
-	tc = devm_kzalloc(dev, sizeof(*tc), GFP_KERNEL);
-	if (!tc)
-		return -ENOMEM;
-
-	tc->dev = dev;
-
 	/* port@2 is the output port */
 	ret = drm_of_find_panel_or_bridge(dev->of_node, 2, 0, &panel, NULL);
 	if (ret && ret != -ENODEV)
@@ -1614,6 +1607,25 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		tc->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
 	}
 
+	return ret;
+}
+
+static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct tc_data *tc;
+	int ret;
+
+	tc = devm_kzalloc(dev, sizeof(*tc), GFP_KERNEL);
+	if (!tc)
+		return -ENOMEM;
+
+	tc->dev = dev;
+
+	ret = tc_probe_edp_bridge_endpoint(tc);
+	if (ret)
+		return ret;
+
 	/* Shut down GPIO is optional */
 	tc->sd_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH);
 	if (IS_ERR(tc->sd_gpio))