[PATCH v2 04/12] drm/bridge: synopsys: dw-dp: Support MEDIA_BUS_FMT_FIXED

[Sebastian Reichel <sebastian.reichel@collabora.com>]

Add support for MEDIA_BUS_FMT_FIXED, which is e.g. requested for USB-C
DP chains as the last bridge in the chain (aux-hpd-bridge) does not
implement atomic_get_output_bus_fmts(), which results in the generic
drm_atomic_bridge_chain_select_bus_fmts() code using MEDIA_BUS_FMT_FIXED
instead.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-dp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
index 6211ba6ba7bd..fc4ddb7792d7 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c
@@ -1528,6 +1528,7 @@ static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
 				     struct drm_connector_state *conn_state)
 {
 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+	unsigned int out_bus_format = bridge_state->output_bus_cfg.format;
 	struct dw_dp *dp = bridge_to_dp(bridge);
 	struct dw_dp_bridge_state *state;
 	const struct dw_dp_output_format *fmt;
@@ -1538,7 +1539,10 @@ static int dw_dp_bridge_atomic_check(struct drm_bridge *bridge,
 	state = to_dw_dp_bridge_state(bridge_state);
 	mode = &state->mode;
 
-	fmt = dw_dp_get_output_format(bridge_state->output_bus_cfg.format);
+	if (out_bus_format == MEDIA_BUS_FMT_FIXED)
+		out_bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+
+	fmt = dw_dp_get_output_format(out_bus_format);
 	if (!fmt)
 		return -EINVAL;
 

-- 
2.53.0