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path: root/drivers/gpu/drm/drm_probe_helper.c
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Diffstat (limited to 'drivers/gpu/drm/drm_probe_helper.c')
-rw-r--r--drivers/gpu/drm/drm_probe_helper.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 682359512996..d77f17867195 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -964,3 +964,39 @@ bool drm_helper_hpd_irq_event(struct drm_device *dev)
return changed;
}
EXPORT_SYMBOL(drm_helper_hpd_irq_event);
+
+/**
+ * drm_connector_helper_get_modes_from_ddc - Updates the connector's EDID
+ * property from the connector's
+ * DDC channel
+ * @connector: The connector
+ *
+ * Returns:
+ * The number of detected display modes.
+ *
+ * Uses a connector's DDC channel to retrieve EDID data and update the
+ * connector's EDID property and display modes. Drivers can use this
+ * function to implement struct &drm_connector_helper_funcs.get_modes
+ * for connectors with a DDC channel.
+ */
+int drm_connector_helper_get_modes_from_ddc(struct drm_connector *connector)
+{
+ struct edid *edid;
+ int count = 0;
+
+ if (!connector->ddc)
+ return 0;
+
+ edid = drm_get_edid(connector, connector->ddc);
+
+ // clears property if EDID is NULL
+ drm_connector_update_edid_property(connector, edid);
+
+ if (edid) {
+ count = drm_add_edid_modes(connector, edid);
+ kfree(edid);
+ }
+
+ return count;
+}
+EXPORT_SYMBOL(drm_connector_helper_get_modes_from_ddc);