[PATCH v3 05/12] drm/mediatek: convert dpi driver to use drm_of_find_panel_or_bridge

[Bibby Hsieh]

From: chunhui dai <chunhui.dai at mediatek.com>

Convert dpi driver to use drm_of_find_panel_or_bridge.
This changes some error messages to debug messages (in the graph core).
Graph connections are often "no connects" depending on the particular
board, so we want to avoid spurious messages. Plus the kernel is not a
DT validator.
related links:
[1] https://lkml.org/lkml/2017/2/3/716
[2] https://lkml.org/lkml/2017/2/3/719

Signed-off-by: chunhui dai <chunhui.dai at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 022ccec49cea..7a4868a0afec 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -14,6 +14,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_of.h>
 #include <linux/kernel.h>
 #include <linux/component.h>
 #include <linux/platform_device.h>
@@ -697,7 +698,6 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct mtk_dpi *dpi;
 	struct resource *mem;
-	struct device_node *bridge_node;
 	int comp_id;
 	int ret;
 
@@ -743,16 +743,14 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	bridge_node = of_graph_get_remote_node(dev->of_node, 0, 0);
-	if (!bridge_node)
-		return -ENODEV;
-
-	dev_info(dev, "Found bridge node: %pOF\n", bridge_node);
-
-	dpi->bridge = of_drm_find_bridge(bridge_node);
-	of_node_put(bridge_node);
-	if (!dpi->bridge)
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
+					  NULL, &dpi->bridge);
+	if (ret) {
+		dev_err(dev, "Failed to find panel or bridge: %d\n", ret);
 		return -EPROBE_DEFER;
+	}
+
+	dev_info(dev, "Found bridge node: %pOF\n", dpi->bridge->of_node);
 
 	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
 	if (comp_id < 0) {
-- 
2.12.5.2.gbdf23ab