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 <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
This commit is contained in:
Thierry Reding 2019-10-21 16:34:28 +02:00
parent 8cda78b128
commit 99c830b8b7

View File

@ -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
*/