drm/edid: Add API to help find connection type

To fill the audio infoframe it is required to identify the
connection type as DP or HDMI. This patch adds an API which
parses ELD and returns the display type connected.
Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Cc: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/drm/drm_edid.h

@@ -403,6 +403,18 @@ static inline int drm_eld_size(const uint8_t *eld)
 	return DRM_ELD_HEADER_BLOCK_SIZE + eld[DRM_ELD_BASELINE_ELD_LEN] * 4;
 }
 
+/**
+ * drm_eld_get_conn_type - Get device type hdmi/dp connected
+ * @eld: pointer to an ELD memory structure
+ *
+ * The caller need to use %DRM_ELD_CONN_TYPE_HDMI or %DRM_ELD_CONN_TYPE_DP to
+ * identify the display type connected.
+ */
+static inline u8 drm_eld_get_conn_type(const uint8_t *eld)
+{
+	return eld[DRM_ELD_SAD_COUNT_CONN_TYPE] & DRM_ELD_CONN_TYPE_MASK;
+}
+
 struct edid *drm_do_get_edid(struct drm_connector *connector,
 	int (*get_edid_block)(void *data, u8 *buf, unsigned int block,
 			      size_t len),