drm/tile: expose the tile property to userspace (v3)

This takes the tiling info from the connector and
exposes it to userspace, as a blob object in a
connector property.

The contents of the blob is ABI.

v2: add property + function documentation.

v3: move property setup from previous patch.
add boilerplate + fix long line (Daniel)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 54 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index eb89327fb737..4a44f894f631 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1344,6 +1344,11 @@ static int drm_mode_create_standard_connector_properties(struct drm_device *dev)
                                        "PATH", 0);
         dev->mode_config.path_property = dev_path;
 
+        dev->mode_config.tile_property = drm_property_create(dev,
+                                                             DRM_MODE_PROP_BLOB |
+                                                             DRM_MODE_PROP_IMMUTABLE,
+                                                             "TILE", 0);
+
         return 0;
 }
 
@@ -4088,6 +4093,52 @@ int drm_mode_connector_set_path_property(struct drm_connector *connector,
 EXPORT_SYMBOL(drm_mode_connector_set_path_property);
 
 /**
+ * drm_mode_connector_set_tile_property - set tile property on connector
+ * @connector: connector to set property on.
+ *
+ * This looks up the tile information for a connector, and creates a
+ * property for userspace to parse if it exists. The property is of
+ * the form of 8 integers using ':' as a separator.
+ *
+ * Returns:
+ * Zero on success, errno on failure.
+ */
+int drm_mode_connector_set_tile_property(struct drm_connector *connector)
+{
+        struct drm_device *dev = connector->dev;
+        int ret, size;
+        char tile[256];
+
+        if (connector->tile_blob_ptr)
+                drm_property_destroy_blob(dev, connector->tile_blob_ptr);
+
+        if (!connector->has_tile) {
+                connector->tile_blob_ptr = NULL;
+                ret = drm_object_property_set_value(&connector->base,
+                                                    dev->mode_config.tile_property, 0);
+                return ret;
+        }
+
+        snprintf(tile, 256, "%d:%d:%d:%d:%d:%d:%d:%d",
+                 connector->tile_group->id, connector->tile_is_single_monitor,
+                 connector->num_h_tile, connector->num_v_tile,
+                 connector->tile_h_loc, connector->tile_v_loc,
+                 connector->tile_h_size, connector->tile_v_size);
+        size = strlen(tile) + 1;
+
+        connector->tile_blob_ptr = drm_property_create_blob(connector->dev,
+                                                            size, tile);
+        if (!connector->tile_blob_ptr)
+                return -EINVAL;
+
+        ret = drm_object_property_set_value(&connector->base,
+                                            dev->mode_config.tile_property,
+                                            connector->tile_blob_ptr->base.id);
+        return ret;
+}
+EXPORT_SYMBOL(drm_mode_connector_set_tile_property);
+
+/**
  * drm_mode_connector_update_edid_property - update the edid property of a connector
  * @connector: drm connector
  * @edid: new value of the edid property
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 0a9d3aad3cba..9a5b68717ec8 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2236,6 +2236,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_
         else
                 edid = drm_get_edid(connector, &port->aux.ddc);
 
+        drm_mode_connector_set_tile_property(connector);
         drm_dp_put_port(port);
         return edid;
 }
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 428bb3041621..7f8c6a66680a 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -414,6 +414,8 @@ static struct drm_connector *intel_dp_add_mst_connector(struct drm_dp_mst_topolo
         intel_dp_add_properties(intel_dp, connector);
 
         drm_object_attach_property(&connector->base, dev->mode_config.path_property, 0);
+        drm_object_attach_property(&connector->base, dev->mode_config.tile_property, 0);
+
         drm_mode_connector_set_path_property(connector, pathprop);
         drm_reinit_primary_mode_group(dev);
         mutex_lock(&dev->mode_config.mutex);