From: Thierry Reding treding@nvidia.com
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 --- drivers/gpu/drm/drm_dp_helper.c | 3 +++ include/drm/drm_dp_helper.h | 9 +++++++++ 2 files changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 664d814ab250..743343527bfa 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -336,6 +336,7 @@ 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, @@ -344,6 +345,7 @@ 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; } EXPORT_SYMBOL(drm_dp_link_caps_copy);
@@ -391,6 +393,7 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) link->caps.enhanced_framing = drm_dp_enhanced_frame_cap(values); link->caps.tps3_supported = drm_dp_tps3_supported(values); link->caps.fast_training = drm_dp_fast_training_cap(values); + link->caps.channel_coding = drm_dp_channel_coding_supported(values);
link->rate = link->max_rate; link->lanes = link->max_lanes; diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 81af618c6b4a..fe7aef2c0736 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -89,6 +89,7 @@ # 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 @@ -983,6 +984,12 @@ drm_dp_fast_training_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) (dpcd[DP_MAX_DOWNSPREAD] & DP_NO_AUX_HANDSHAKE_LINK_TRAINING); }
+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 */ @@ -1112,11 +1119,13 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, * @enhanced_framing: enhanced framing capability (mandatory as of DP 1.2) * @tps3_supported: training pattern sequence 3 supported for equalization * @fast_training: AUX CH handshake not required for link training + * @channel_coding: ANSI 8B/10B channel coding capability */ struct drm_dp_link_caps { bool enhanced_framing; bool tps3_supported; bool fast_training; + bool channel_coding; };
void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest,