drm/exynos: dsi: add support for MIC driver as a bridge

MIC must be initilized by MIPI DSI when it is being bound.
Signed-off-by: Hyungwon Hwang <human.hwang@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

Documentation/devicetree/bindings/video/exynos_dsim.txt

@@ -32,10 +32,19 @@ Video interfaces:
   Device node can contain video interface port nodes according to [2].
   The following are properties specific to those nodes:
 
-  port node:
-    - reg: (required) can be 0 for input RGB/I80 port or 1 for DSI port;
+  port node inbound:
+    - reg: (required) must be 0.
+  port node outbound:
+    - reg: (required) must be 1.
 
-  endpoint node of DSI port (reg = 1):
+  endpoint node connected from mic node (reg = 0):
+    - remote-endpoint: specifies the endpoint in mic node. This node is required
+		       for Exynos5433 mipi dsi. So mic can access to panel node
+		       thoughout this dsi node.
+  endpoint node connected to panel node (reg = 1):
+    - remote-endpoint: specifies the endpoint in panel node. This node is
+		       required in all kinds of exynos mipi dsi to represent
+		       the connection between mipi dsi and panel.
     - samsung,burst-clock-frequency: specifies DSI frequency in high-speed burst
       mode
     - samsung,esc-clock-frequency: specifies DSI frequency in escape mode
@@ -74,7 +83,15 @@ Example:
 			#address-cells = <1>;
 			#size-cells = <0>;
 
+			port@0 {
+				reg = <0>;
+				decon_to_mic: endpoint {
+					remote-endpoint = <&mic_to_decon>;
+				};
+			};
+
 			port@1 {
+				reg = <1>;
 				dsi_ep: endpoint {
 					reg = <0>;
 					samsung,burst-clock-frequency = <500000000>;

drivers/gpu/drm/exynos/exynos_drm_dsi.c

@@ -21,6 +21,7 @@
 #include <linux/irq.h>
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
+#include <linux/of_graph.h>
 #include <linux/phy/phy.h>
 #include <linux/regulator/consumer.h>
 #include <linux/component.h>
@@ -288,6 +289,7 @@ struct exynos_dsi {
 	struct list_head transfer_list;
 
 	struct exynos_dsi_driver_data *driver_data;
+	struct device_node *bridge_node;
 };
 
 #define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host)
@@ -1794,7 +1796,22 @@ static int exynos_dsi_parse_dt(struct exynos_dsi *dsi)
 
 	ret = exynos_dsi_of_read_u32(ep, "samsung,esc-clock-frequency",
 				     &dsi->esc_clk_rate);
+	if (ret < 0)
+		goto end;
+
+	of_node_put(ep);
+
+	ep = of_graph_get_next_endpoint(node, NULL);
+	if (!ep) {
+		ret = -ENXIO;
+		goto end;
+	}
 
+	dsi->bridge_node = of_graph_get_remote_port_parent(ep);
+	if (!dsi->bridge_node) {
+		ret = -ENXIO;
+		goto end;
+	}
 end:
 	of_node_put(ep);
 
@@ -1807,6 +1824,7 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,
 	struct exynos_drm_display *display = dev_get_drvdata(dev);
 	struct exynos_dsi *dsi = display_to_dsi(display);
 	struct drm_device *drm_dev = data;
+	struct drm_bridge *bridge;
 	int ret;
 
 	ret = exynos_drm_create_enc_conn(drm_dev, display);
@@ -1816,6 +1834,12 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,
 		return ret;
 	}
 
+	bridge = of_drm_find_bridge(dsi->bridge_node);
+	if (bridge) {
+		display->encoder->bridge = bridge;
+		drm_bridge_attach(drm_dev, bridge);
+	}
+
 	return mipi_dsi_host_register(&dsi->dsi_host);
 }