Add support for HPD coming from somewhere else in the drm_bridge chain. Skip signaling HPD sate when "no-hpd" is present in the DT node backing the dp_typec bridge. Add this support because some EC firmwares on Trogdor/Strongbad boards don't properly indicate the state of the DP HPD level on a type-c port. The EC only indicates that DP mode is entered or exited for a type-c port. The HPD level is expressed to the DP controller via a pin on the AP that the EC drives high or low when the type-c port partner (i.e. monitor) asserts or deasserts HPD. Cc: Prashant Malani <pmalani@xxxxxxxxxxxx> Cc: Benson Leung <bleung@xxxxxxxxxxxx> Cc: Tzung-Bi Shih <tzungbi@xxxxxxxxxx> Cc: <chrome-platform@xxxxxxxxxxxxxxx> Cc: Pin-yen Lin <treapking@xxxxxxxxxxxx> Cc: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> --- drivers/gpu/drm/bridge/aux-hpd-bridge.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c index 3d33f7936cbc..adafda4f128f 100644 --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c @@ -22,6 +22,7 @@ static DEFINE_IDA(drm_aux_hpd_bridge_ida); struct drm_aux_hpd_bridge_data { struct drm_bridge bridge; struct device *dev; + bool no_hpd; }; enum dp_lane { @@ -354,6 +355,8 @@ void drm_aux_hpd_bridge_notify(struct device *dev, enum drm_connector_status sta if (!data) return; + if (data->no_hpd) + return; drm_bridge_hpd_notify(&data->bridge, status); } @@ -662,6 +665,7 @@ static int drm_aux_hpd_bridge_probe(struct auxiliary_device *auxdev, return -ENOMEM; bridge = &hpd_data->bridge; bridge->funcs = &drm_aux_hpd_bridge_funcs; + bridge->ops = DRM_BRIDGE_OP_HPD; } else if (id->driver_data == DRM_AUX_TYPEC_BRIDGE) { typec_data = devm_kzalloc(dev, sizeof(*typec_data), GFP_KERNEL); if (!typec_data) @@ -670,6 +674,9 @@ static int drm_aux_hpd_bridge_probe(struct auxiliary_device *auxdev, bridge = &hpd_data->bridge; bridge->funcs = &drm_dp_typec_bridge_funcs; typec_bridge_dev = to_drm_dp_typec_bridge_dev(dev); + hpd_data->no_hpd = of_property_read_bool(np, "no-hpd"); + if (!hpd_data->no_hpd) + bridge->ops = DRM_BRIDGE_OP_HPD; memcpy(typec_data->dp_lanes, dp_lanes, sizeof(typec_data->dp_lanes)); ret = drm_dp_typec_bridge_probe_typec_ports(typec_data, typec_bridge_dev, np); if (ret) @@ -679,8 +686,7 @@ static int drm_aux_hpd_bridge_probe(struct auxiliary_device *auxdev, } hpd_data->dev = dev; - bridge->of_node = dev_get_platdata(dev); - bridge->ops = DRM_BRIDGE_OP_HPD; + bridge->of_node = np; bridge->type = DRM_MODE_CONNECTOR_DisplayPort; auxiliary_set_drvdata(auxdev, hpd_data); -- https://chromeos.dev