[PATCH 04/15] drm/dp: Add drm_dp_channel_coding_supported() helper

[Lyude Paul]

Reviewed-by: Lyude Paul <lyude at redhat.com>

On Tue, 2019-10-15 at 16:34 +0200, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
> 
> Add a helper to check whether the sink supports ANSI 8B/10B channel
> coding capability as specified in ANSI X3.230-1994, clause 11.
> 
> Signed-off-by: Thierry Reding <treding at nvidia.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 def3b3a543a2..7ff7bf0e742d 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
> @@ -1283,6 +1284,12 @@ 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
>   */
-- 
Cheers,
	Lyude Paul