DP 1.4 has Forward Error Correction Support(FEC). Add helper function to check if the sink device supports FEC.

v2: Separate the helper and the code that uses the helper into two separate patches. (Manasi)

v3: - Move the code to drm_dp_helper.c (Manasi) - change the return type, code style changes (Gaurav) - Use drm_dp_dpcd_readb instead of drm_dp_dpcd_read. (Jani)

v4: - Avoid aux reads everytime, instead read cached values of dpcd register (jani) - Move helper to drm_dp_helper.h like other dsc helpers.(Anusha)

v5: rebased. Change the helper parameter suitably.

Cc: dri-devel@lists.freedesktop.org Cc: Ville Syrjala ville.syrjala@linux.intel.com Cc: Jani Nikula jani.nikula@linux.intel.com Cc: Manasi Navare manasi.d.navare@intel.com Signed-off-by: Anusha Srivatsa anusha.srivatsa@intel.com Reviewed-by: Manasi Navare manasi.d.navare@intel.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 2649529d0d8f..b08f50b852f5 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1101,6 +1101,13 @@ drm_dp_dsc_sink_max_slice_width(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]) DP_DSC_SLICE_WIDTH_MULTIPLIER; }

+/* Forward Error Correction Support on DP 1.4 */ +static inline bool +drm_dp_sink_supports_fec(const u8 fec_capable) +{ + return fec_capable & DP_FEC_CAPABLE; +} + /* * DisplayPort AUX channel */