drm/bridge: dw-hdmi: document the output_port field

The meaning of this flag may not be obvious at first sight.

Reviewed-by: Liu Ying <victor.liu@nxp.com>
Tested-by: Martyn Welch <martyn.welch@collabora.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # TQMa8MPxL/MBa8MPxL
Tested-by: Damon Ding <damon.ding@rock-chips.com> # rk3399
Link: https://patch.msgid.link/20260407-drm-lcdif-dbanc-v4-5-247a16e61ef9@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index 336f062e1f9d9d3062b647f67927473d6b8ab2dc..8500dd4f99d8c19455402ccb19e82b64ae7a7f33 100644 (file)
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -126,6 +126,12 @@ struct dw_hdmi_phy_ops {
 struct dw_hdmi_plat_data {
        struct regmap *regm;
 
+       /*
+        * The HDMI output port number must be 1 if the port is described
+        * in the device tree. 0 if the device tree does not describe the
+        * next component (legacy mode, i.e. without
+        * DRM_BRIDGE_ATTACH_NO_CONNECTOR flag when attaching bridge).
+        */
        unsigned int output_port;
 
        unsigned long input_bus_encoding;