From 1ec0759580023f0eea43eb39f62d1c9327c01091 Mon Sep 17 00:00:00 2001
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Date: Tue, 30 Jun 2020 02:33:19 +0300
Subject: drm: panel: simple: Drop drive/sample bus flags for LVDS panels
Git-commit: c4715837b023930250c9a754db3309c4b701cc0d
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

The DRM bus flags reporting on which clock edge the pixel data and sync
signals are sampled or driven don't make sense for LVDS panels, as the
bus then uses sub-clock timings to send data. Drop those flags and add a
warning in the probe function to make sure the mistake won't be
repeated.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200629233320.8774-4-laurent.pinchart+renesas@ideasonboard.com
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/panel/panel-simple.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index d7c91a16564d..1f07e5283590 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -549,6 +549,14 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc)
 			panel_simple_parse_panel_timing_node(dev, panel, &dt);
 	}
 
+	if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS)
+		/* Catch common mistakes for LVDS panels. */
+		WARN_ON(desc->bus_flags &
+			~(DRM_BUS_FLAG_DE_LOW |
+			  DRM_BUS_FLAG_DE_HIGH |
+			  DRM_BUS_FLAG_DATA_MSB_TO_LSB |
+			  DRM_BUS_FLAG_DATA_LSB_TO_MSB));
+
 	drm_panel_init(&panel->base, dev, &panel_simple_funcs,
 		       desc->connector_type);
 
@@ -688,7 +696,7 @@ static const struct panel_desc auo_b101aw03 = {
 		.height = 125,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -1412,7 +1420,7 @@ static const struct panel_desc chunghwa_claa070wp03xg = {
 		.height = 150,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -1437,7 +1445,7 @@ static const struct panel_desc chunghwa_claa101wa01a = {
 		.height = 120,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -1462,7 +1470,7 @@ static const struct panel_desc chunghwa_claa101wb01 = {
 		.height = 125,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -2137,7 +2145,7 @@ static const struct panel_desc innolux_n156bge_l21 = {
 		.height = 193,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -2270,7 +2278,7 @@ static const struct panel_desc koe_tx26d202vm0bwa = {
 		.disable = 1000,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -2511,9 +2519,7 @@ static const struct panel_desc logictechno_lt170410_2whc = {
 		.height = 136,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH |
-		     DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE |
-		     DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -3088,7 +3094,7 @@ static const struct panel_desc samsung_ltn101nt05 = {
 		.height = 125,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
@@ -3528,7 +3534,7 @@ static const struct panel_desc toshiba_lt089ac29000 = {
 		.height = 116,
 	},
 	.bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,
-	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH,
 	.connector_type = DRM_MODE_CONNECTOR_LVDS,
 };
 
-- 
2.29.2