[PATCH v2 4/4] drm: panel: simple: Warn in case of incorrect bus format for LVDS panels

[Laurent Pinchart]

Only the MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
MEDIA_BUS_FMT_RGB888_1X7X4_SPWG and MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA bus
formats are valid for LVDS panels. Warn at probe time to catch the
common mistake of using an incorrect format, as well as discrepancies
between the bus format and the reported bpc.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
---
 drivers/gpu/drm/panel/panel-simple.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index cd416376bf71..3a35f74d6cb7 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -549,13 +549,22 @@ 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)
+	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));
+		WARN_ON(desc->bus_format != MEDIA_BUS_FMT_RGB666_1X7X3_SPWG &&
+			desc->bus_format != MEDIA_BUS_FMT_RGB888_1X7X4_SPWG &&
+			desc->bus_format != MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA);
+		WARN_ON(desc->bus_format == MEDIA_BUS_FMT_RGB666_1X7X3_SPWG &&
+			desc->bpc != 6);
+		WARN_ON((desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_SPWG ||
+			 desc->bus_format == MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA) &&
+			desc->bpc != 8);
+	}
 
 	drm_panel_init(&panel->base, dev, &panel_simple_funcs,
 		       desc->connector_type);
-- 
Regards,

Laurent Pinchart