[PATCH V3 6/8] drm/exynos: dp: Modify driver to support bridge chaining

[Ajay Kumar]

exynos_dp supports a simple bridge chain with ptn3460 bridge
and an LVDS panel attached to it.
This patch creates the bridge chain with ptn3460 as the head
of the list and panel_binder being the tail.

Also, DERER_PROBE for exynos_dp is tested with this patch.

Signed-off-by: Ajay Kumar <ajaykumar.rs at samsung.com>
---
 .../devicetree/bindings/video/exynos_dp.txt        |    2 +
 drivers/gpu/drm/exynos/Kconfig                     |    1 +
 drivers/gpu/drm/exynos/exynos_dp_core.c            |   39 +++++++++++++++-----
 drivers/gpu/drm/exynos/exynos_dp_core.h            |    1 +
 4 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/video/exynos_dp.txt b/Documentation/devicetree/bindings/video/exynos_dp.txt
index 53dbccf..0c118ff 100644
--- a/Documentation/devicetree/bindings/video/exynos_dp.txt
+++ b/Documentation/devicetree/bindings/video/exynos_dp.txt
@@ -51,6 +51,8 @@ Required properties for dp-controller:
 			LANE_COUNT1 = 1, LANE_COUNT2 = 2, LANE_COUNT4 = 4
 	- display-timings: timings for the connected panel as described by
 		Documentation/devicetree/bindings/video/display-timing.txt
+	-edp-panel:
+		phandle for the drm_panel node required by panel_binder.
 
 Optional properties for dp-controller:
 	-interlaced:
diff --git a/drivers/gpu/drm/exynos/Kconfig b/drivers/gpu/drm/exynos/Kconfig
index 178d2a9..fd1c070 100644
--- a/drivers/gpu/drm/exynos/Kconfig
+++ b/drivers/gpu/drm/exynos/Kconfig
@@ -52,6 +52,7 @@ config DRM_EXYNOS_DP
 	bool "EXYNOS DRM DP driver support"
 	depends on DRM_EXYNOS_FIMD && ARCH_EXYNOS && (DRM_PTN3460=n || DRM_PTN3460=y || DRM_PTN3460=DRM_EXYNOS)
 	default DRM_EXYNOS
+	select DRM_PANEL
 	help
 	  This enables support for DP device.
 
diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/drm/exynos/exynos_dp_core.c
index 414f5e5..a608f5c 100644
--- a/drivers/gpu/drm/exynos/exynos_dp_core.c
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.c
@@ -28,7 +28,9 @@
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_panel.h>
 #include <drm/bridge/ptn3460.h>
+#include <drm/bridge/panel_binder.h>
 
 #include "exynos_drm_drv.h"
 #include "exynos_dp_core.h"
@@ -983,7 +985,7 @@ static int exynos_drm_attach_lcd_bridge(struct exynos_dp_device *dp,
 		struct drm_encoder *encoder)
 {
 	struct bridge_init bridge;
-	struct drm_bridge *bridge_chain = NULL;
+	struct drm_bridge *bridge_chain = NULL, *next = NULL;
 	bool connector_created = false;
 
 	if (find_bridge("nxp,ptn3460", &bridge)) {
@@ -991,6 +993,14 @@ static int exynos_drm_attach_lcd_bridge(struct exynos_dp_device *dp,
 								bridge.node);
 	}
 
+	if (dp->edp_panel) {
+		next = panel_binder_init(dp->drm_dev, encoder, bridge.client,
+			bridge.node, dp->edp_panel, DRM_CONNECTOR_POLL_HPD);
+		if (next)
+			connector_created = true;
+		drm_bridge_add_to_chain(bridge_chain, next);
+	}
+
 	return connector_created;
 }
 
@@ -1215,16 +1225,10 @@ static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct drm_device *drm_dev = data;
 	struct resource *res;
-	struct exynos_dp_device *dp;
+	struct exynos_dp_device *dp = exynos_dp_display.ctx;
 	unsigned int irq_flags;
-
 	int ret = 0;
 
-	dp = devm_kzalloc(&pdev->dev, sizeof(struct exynos_dp_device),
-				GFP_KERNEL);
-	if (!dp)
-		return -ENOMEM;
-
 	dp->dev = &pdev->dev;
 	dp->dpms_mode = DRM_MODE_DPMS_OFF;
 
@@ -1298,7 +1302,6 @@ static int exynos_dp_bind(struct device *dev, struct device *master, void *data)
 	disable_irq(dp->irq);
 
 	dp->drm_dev = drm_dev;
-	exynos_dp_display.ctx = dp;
 
 	platform_set_drvdata(pdev, &exynos_dp_display);
 
@@ -1325,6 +1328,9 @@ static const struct component_ops exynos_dp_ops = {
 
 static int exynos_dp_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
+	struct device_node *panel_node;
+	struct exynos_dp_device *dp;
 	int ret;
 
 	ret = exynos_drm_component_add(&pdev->dev, EXYNOS_DEVICE_TYPE_CONNECTOR,
@@ -1332,6 +1338,21 @@ static int exynos_dp_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	dp = devm_kzalloc(&pdev->dev, sizeof(struct exynos_dp_device),
+				GFP_KERNEL);
+	if (!dp)
+		return -ENOMEM;
+
+	panel_node = of_parse_phandle(dev->of_node, "edp-panel", 0);
+	if (panel_node) {
+		dp->edp_panel = of_drm_find_panel(panel_node);
+		of_node_put(panel_node);
+		if (!dp->edp_panel)
+			return -EPROBE_DEFER;
+	}
+
+	exynos_dp_display.ctx = dp;
+
 	ret = component_add(&pdev->dev, &exynos_dp_ops);
 	if (ret)
 		exynos_drm_component_del(&pdev->dev,
diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.h b/drivers/gpu/drm/exynos/exynos_dp_core.h
index 02cc4f9..26a64d3 100644
--- a/drivers/gpu/drm/exynos/exynos_dp_core.h
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.h
@@ -149,6 +149,7 @@ struct exynos_dp_device {
 	struct drm_device	*drm_dev;
 	struct drm_connector	connector;
 	struct drm_encoder	*encoder;
+	struct drm_panel	*edp_panel;
 	struct clk		*clock;
 	unsigned int		irq;
 	void __iomem		*reg_base;
-- 
1.7.9.5