drm/radeon: add DisplayPort MST support (v2)

This adds initial DP 1.2 MST support to radeon, on CAYMAN
and up in theory.

This is off by default.

v2: agd5f:
- add UNIPHY3 offsets
- move atom cmd table code into atombios_encoders.c
- whitespace cleanup
- replace some magic numbers with proper defines

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 61 insertions, 3 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 0a371a13da94..7ffa7d5563b9 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -27,6 +27,7 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_dp_mst_helper.h>
 #include <drm/radeon_drm.h>
 #include "radeon.h"
 #include "radeon_audio.h"
@@ -34,12 +35,33 @@
 
 #include <linux/pm_runtime.h>
 
+static int radeon_dp_handle_hpd(struct drm_connector *connector)
+{
+	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
+	int ret;
+
+	ret = radeon_dp_mst_check_status(radeon_connector);
+	if (ret == -EINVAL)
+		return 1;
+	return 0;
+}
 void radeon_connector_hotplug(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
 	struct radeon_device *rdev = dev->dev_private;
 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
 
+	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
+		struct radeon_connector_atom_dig *dig_connector =
+			radeon_connector->con_priv;
+
+		if (radeon_connector->is_mst_connector)
+			return;
+		if (dig_connector->is_mst) {
+			radeon_dp_handle_hpd(connector);
+			return;
+		}
+	}
 	/* bail if the connector does not have hpd pin, e.g.,
 	 * VGA, TV, etc.
 	 */
@@ -1609,6 +1631,9 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
 	struct drm_encoder *encoder = radeon_best_single_encoder(connector);
 	int r;
 
+	if (radeon_dig_connector->is_mst)
+		return connector_status_disconnected;
+
 	r = pm_runtime_get_sync(connector->dev->dev);
 	if (r < 0)
 		return connector_status_disconnected;
@@ -1667,12 +1692,21 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
 		radeon_dig_connector->dp_sink_type = radeon_dp_getsinktype(radeon_connector);
 		if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd)) {
 			ret = connector_status_connected;
-			if (radeon_dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT)
+			if (radeon_dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) {
 				radeon_dp_getdpcd(radeon_connector);
+				r = radeon_dp_mst_probe(radeon_connector);
+				if (r == 1)
+					ret = connector_status_disconnected;
+			}
 		} else {
 			if (radeon_dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) {
-				if (radeon_dp_getdpcd(radeon_connector))
-					ret = connector_status_connected;
+				if (radeon_dp_getdpcd(radeon_connector)) {
+					r = radeon_dp_mst_probe(radeon_connector);
+					if (r == 1)
+						ret = connector_status_disconnected;
+					else
+						ret = connector_status_connected;
+				}
 			} else {
 				/* try non-aux ddc (DP to DVI/HDMI/etc. adapter) */
 				if (radeon_ddc_probe(radeon_connector, false))
@@ -2404,3 +2438,27 @@ radeon_add_legacy_connector(struct drm_device *dev,
 	connector->display_info.subpixel_order = subpixel_order;
 	drm_connector_register(connector);
 }
+
+void radeon_setup_mst_connector(struct drm_device *dev)
+{
+	struct radeon_device *rdev = dev->dev_private;
+	struct drm_connector *connector;
+	struct radeon_connector *radeon_connector;
+
+	if (!ASIC_IS_DCE5(rdev))
+		return;
+
+	if (radeon_mst == 0)
+		return;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		int ret;
+
+		radeon_connector = to_radeon_connector(connector);
+
+		if (connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort)
+			continue;
+
+		ret = radeon_dp_mst_init(radeon_connector);
+	}
+}