From: Thierry Reding treding@nvidia.com
If the sink supports eDP, read the eDP revision from it's DPCD.
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_dp_helper.c | 15 +++++++++++++++ include/drm/drm_dp_helper.h | 8 ++++++++ 2 files changed, 23 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 0cf5b1c278ae..8d8112a4fee0 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -327,6 +327,7 @@ static void drm_dp_link_reset(struct drm_dp_link *link) link->max_lanes = 0;
drm_dp_link_caps_reset(&link->caps); + link->edp = 0;
link->rate = 0; link->lanes = 0; @@ -363,6 +364,20 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) link->caps.fast_training = drm_dp_fast_training_cap(values); link->caps.channel_coding = drm_dp_channel_coding_supported(values);
+ if (drm_dp_alternate_scrambler_reset_cap(values)) { + static const u8 edp_revs[] = { 0x11, 0x12, 0x13, 0x14 }; + u8 value; + + err = drm_dp_dpcd_readb(aux, DP_EDP_DPCD_REV, &value); + if (err < 0) + return err; + + if (value >= ARRAY_SIZE(edp_revs)) + DRM_ERROR("unsupported eDP version: %02x\n", value); + else + link->edp = edp_revs[value]; + } + 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 201e654b2257..1f7b137d01b6 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -659,6 +659,13 @@ drm_dp_channel_coding_supported(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) return dpcd[DP_MAIN_LINK_CHANNEL_CODING] & DP_CAP_ANSI_8B10B; }
+static inline bool +drm_dp_alternate_scrambler_reset_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + return dpcd[DP_EDP_CONFIGURATION_CAP] & + DP_ALTERNATE_SCRAMBLER_RESET_CAP; +} + /* * DisplayPort AUX channel */ @@ -785,6 +792,7 @@ struct drm_dp_link { unsigned int max_lanes;
struct drm_dp_link_caps caps; + unsigned char edp;
unsigned int rate; unsigned int lanes;