From 99c830b8b7bef939dfcd385553b39a5d5b278a03 Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Mon, 21 Oct 2019 16:34:28 +0200
Subject: drm/dp: Add drm_dp_channel_coding_supported() helper
Git-commit: 99c830b8b7bef939dfcd385553b39a5d5b278a03
Patch-mainline: v5.5-rc1
References: bsc#1152472
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 <lyude@redhat.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021143437.1477719-5-thierry.reding@gmail.com
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
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
*/
--
2.28.0