drm/bridge: use bus flags in bridge timings

The DRM bus flags convey additional information on pixel data on
the bus. All current available bus flags might be of interest for
a bridge. Remove the sampling_edge field and use bus_flags.

In the case at hand a dumb VGA bridge needs a specific data enable
polarity (DRM_BUS_FLAG_DE_LOW).
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/bridge/dumb-vga-dac.c

@@ -234,7 +234,7 @@ static int dumb_vga_remove(struct platform_device *pdev)
  */
 static const struct drm_bridge_timings default_dac_timings = {
 	/* Timing specifications, datasheet page 7 */
-	.sampling_edge = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
+	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
 	.setup_time_ps = 500,
 	.hold_time_ps = 1500,
 };
@@ -245,7 +245,7 @@ static const struct drm_bridge_timings default_dac_timings = {
  */
 static const struct drm_bridge_timings ti_ths8134_dac_timings = {
 	/* From timing diagram, datasheet page 9 */
-	.sampling_edge = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
+	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
 	/* From datasheet, page 12 */
 	.setup_time_ps = 3000,
 	/* I guess this means latched input */
@@ -258,7 +258,7 @@ static const struct drm_bridge_timings ti_ths8134_dac_timings = {
  */
 static const struct drm_bridge_timings ti_ths8135_dac_timings = {
 	/* From timing diagram, datasheet page 14 */
-	.sampling_edge = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
+	.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
 	/* From datasheet, page 16 */
 	.setup_time_ps = 2000,
 	.hold_time_ps = 500,

include/drm/drm_bridge.h

@@ -244,15 +244,13 @@ struct drm_bridge_funcs {
  */
 struct drm_bridge_timings {
 	/**
-	 * @sampling_edge:
+	 * @input_bus_flags:
 	 *
-	 * Tells whether the bridge samples the digital input signals from the
-	 * display engine on the positive or negative edge of the clock. This
-	 * should use the DRM_BUS_FLAG_PIXDATA_SAMPLE_[POS|NEG]EDGE and
-	 * DRM_BUS_FLAG_SYNC_SAMPLE_[POS|NEG]EDGE bitwise flags from the DRM
-	 * connector (bit 2, 3, 6 and 7 valid).
+	 * Tells what additional settings for the pixel data on the bus
+	 * this bridge requires (like pixel signal polarity). See also
+	 * &drm_display_info->bus_flags.
 	 */
-	u32 sampling_edge;
+	u32 input_bus_flags;
 	/**
 	 * @setup_time_ps:
 	 *