drm/dp: Add drm_dp_alternate_scrambler_reset_cap() helper

Add a helper to check if the sink supports the eDP alternate scrambler
reset value of 0xfffe.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021143437.1477719-6-thierry.reding@gmail.com

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index bc276c80b927317c050919fd4bd57fe9955cb384..b3402cb186a47f2c27a68e5ece5c3a9562c74028 100644 (file)
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1294,6 +1294,13 @@ drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
        return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B;
 }
 
+static inline bool
+drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
+{
+       return dpcd[DP_EDP_CONFIGURATION_CAP] &
+                       DP_ALTERNATE_SCRAMBLER_RESET_CAP;
+}
+
 /*
  * DisplayPort AUX channel
  */