drm/radeon/kms: fix support for DDC on dp bridges

Need to set up the bridge for DDC prior to the
i2c over aux transaction.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 29 insertions, 4 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index dc7852b3c5ca..613e36f83b71 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -44,6 +44,8 @@ extern void
 radeon_legacy_backlight_init(struct radeon_encoder *radeon_encoder,
                              struct drm_connector *drm_connector);
 
+bool radeon_connector_encoder_is_dp_bridge(struct drm_connector *connector);
+
 void radeon_connector_hotplug(struct drm_connector *connector)
 {
         struct drm_device *dev = connector->dev;
@@ -1070,10 +1072,10 @@ static int radeon_dp_get_modes(struct drm_connector *connector)
 {
         struct radeon_connector *radeon_connector = to_radeon_connector(connector);
         struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
+        struct drm_encoder *encoder = radeon_best_single_encoder(connector);
         int ret;
 
         if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
-                struct drm_encoder *encoder;
                 struct drm_display_mode *mode;
 
                 if (!radeon_dig_connector->edp_on)
@@ -1085,7 +1087,6 @@ static int radeon_dp_get_modes(struct drm_connector *connector)
                                                      ATOM_TRANSMITTER_ACTION_POWER_OFF);
 
                 if (ret > 0) {
-                        encoder = radeon_best_single_encoder(connector);
                         if (encoder) {
                                 radeon_fixup_lvds_native_mode(encoder, connector);
                                 /* add scaled modes */
@@ -1109,8 +1110,14 @@ static int radeon_dp_get_modes(struct drm_connector *connector)
                         /* add scaled modes */
                         radeon_add_common_modes(encoder, connector);
                 }
-        } else
+        } else {
+                /* need to setup ddc on the bridge */
+                if (radeon_connector_encoder_is_dp_bridge(connector)) {
+                        if (encoder)
+                                radeon_atom_ext_encoder_setup_ddc(encoder);
+                }
                 ret = radeon_ddc_get_modes(radeon_connector);
+        }
 
         return ret;
 }
@@ -1194,6 +1201,7 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
         struct radeon_connector *radeon_connector = to_radeon_connector(connector);
         enum drm_connector_status ret = connector_status_disconnected;
         struct radeon_connector_atom_dig *radeon_dig_connector = radeon_connector->con_priv;
+        struct drm_encoder *encoder = radeon_best_single_encoder(connector);
 
         if (radeon_connector->edid) {
                 kfree(radeon_connector->edid);
@@ -1201,7 +1209,6 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
         }
 
         if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
-                struct drm_encoder *encoder = radeon_best_single_encoder(connector);
                 if (encoder) {
                         struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
                         struct drm_display_mode *native_mode = &radeon_encoder->native_mode;
@@ -1221,6 +1228,11 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
                         atombios_set_edp_panel_power(connector,
                                                      ATOM_TRANSMITTER_ACTION_POWER_OFF);
         } else {
+                /* need to setup ddc on the bridge */
+                if (radeon_connector_encoder_is_dp_bridge(connector)) {
+                        if (encoder)
+                                radeon_atom_ext_encoder_setup_ddc(encoder);
+                }
                 radeon_dig_connector->dp_sink_type = radeon_dp_getsinktype(radeon_connector);
                 if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd)) {
                         ret = connector_status_connected;
diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c
index d3449443aa1f..8e058f1f46d6 100644
--- a/drivers/gpu/drm/radeon/radeon_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_encoders.c
@@ -2046,6 +2046,18 @@ radeon_atom_dig_detect(struct drm_encoder *encoder, struct drm_connector *connec
         return connector_status_disconnected;
 }
 
+void
+radeon_atom_ext_encoder_setup_ddc(struct drm_encoder *encoder)
+{
+        struct drm_encoder *ext_encoder = radeon_atom_get_external_encoder(encoder);
+
+        if (ext_encoder)
+                /* ddc_setup on the dp bridge */
+                atombios_external_encoder_setup(encoder, ext_encoder,
+                                                EXTERNAL_ENCODER_ACTION_V3_DDC_SETUP);
+
+}
+
 static void radeon_atom_encoder_prepare(struct drm_encoder *encoder)
 {
         struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h b/drivers/gpu/drm/radeon/radeon_mode.h
index 977a341266b6..f734b3737dce 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -483,6 +483,7 @@ extern void radeon_atom_encoder_init(struct radeon_device *rdev);
 extern void atombios_dig_transmitter_setup(struct drm_encoder *encoder,
                                            int action, uint8_t lane_num,
                                            uint8_t lane_set);
+extern void radeon_atom_ext_encoder_setup_ddc(struct drm_encoder *encoder);
 extern int radeon_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
                                 u8 write_byte, u8 *read_byte);