From 99c830b8b7bef939dfcd385553b39a5d5b278a03 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Mon, 21 Oct 2019 16:34:28 +0200 Subject: [PATCH] drm/dp: Add drm_dp_channel_coding_supported() helper Add a helper to check whether the sink supports ANSI 8B/10B channel coding capability as specified in ANSI X3.230-1994, clause 11. Reviewed-by: Lyude Paul Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20191021143437.1477719-5-thierry.reding@gmail.com --- include/drm/drm_dp_helper.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 1179d3f2ba7c..bc276c80b927 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -137,6 +137,7 @@ # define DP_DETAILED_CAP_INFO_AVAILABLE (1 << 4) /* DPI */ #define DP_MAIN_LINK_CHANNEL_CODING 0x006 +# define DP_CAP_ANSI_8B10B (1 << 0) #define DP_DOWN_STREAM_PORT_COUNT 0x007 # define DP_PORT_COUNT_MASK 0x0f @@ -1287,6 +1288,12 @@ drm_dp_sink_supports_fec(const u8 fec_capable) return fec_capable & DP_FEC_CAPABLE; } +static inline bool +drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B; +} + /* * DisplayPort AUX channel */ -- 2.39.5