From 6c651b13e436030f996bcfb2f76833af94e44531 Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Mon, 5 Feb 2018 14:07:57 +0100
Subject: drm/tegra: dp: Read channel coding capability from sink
Git-commit: 6c651b13e436030f996bcfb2f76833af94e44531
Patch-mainline: v5.5-rc1
References: bsc#1152472

Parse from the sink capabilities whether or not it supports ANSI 8B/10B
channel coding as specified in ANSI X3.230-1994, clause 11.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/tegra/dp.c | 3 +++
 drivers/gpu/drm/tegra/dp.h | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/tegra/dp.c b/drivers/gpu/drm/tegra/dp.c
index e22ebab677b9..0bd87cff4575 100644
--- a/drivers/gpu/drm/tegra/dp.c
+++ b/drivers/gpu/drm/tegra/dp.c
@@ -13,6 +13,7 @@ static void drm_dp_link_caps_reset(struct drm_dp_link_caps *caps)
 	caps->enhanced_framing = false;
 	caps->tps3_supported = false;
 	caps->fast_training = false;
+	caps->channel_coding = false;
 }
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
@@ -21,6 +22,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
 	dest->enhanced_framing = src->enhanced_framing;
 	dest->tps3_supported = src->tps3_supported;
 	dest->fast_training = src->fast_training;
+	dest->channel_coding = src->channel_coding;
 }
 
 static void drm_dp_link_reset(struct drm_dp_link *link)
@@ -67,6 +69,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
 	link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(dpcd);
 	link->caps.tps3_supported = drm_dp_tps3_supported(dpcd);
 	link->caps.fast_training = drm_dp_fast_training_cap(dpcd);
+	link->caps.channel_coding = drm_dp_channel_coding_supported(dpcd);
 
 	link->rate = link->max_rate;
 	link->lanes = link->max_lanes;
diff --git a/drivers/gpu/drm/tegra/dp.h b/drivers/gpu/drm/tegra/dp.h
index 999078812943..984dac21568e 100644
--- a/drivers/gpu/drm/tegra/dp.h
+++ b/drivers/gpu/drm/tegra/dp.h
@@ -35,6 +35,13 @@ struct drm_dp_link_caps {
 	 * AUX CH handshake not required for link training
 	 */
 	bool fast_training;
+
+	/**
+	 * @channel_coding:
+	 *
+	 * ANSI 8B/10B channel coding capability
+	 */
+	bool channel_coding;
 };
 
 void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,
-- 
2.28.0