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 | 16 +++++++++++++++- include/drm/drm_dp_helper.h | 2 ++ 2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index acab8dc48e2c..5b36e8e39ca7 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -382,6 +382,7 @@ 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; @@ -418,9 +419,22 @@ 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)) + if (drm_dp_alternate_scrambler_reset_cap(values)) { + static const u8 edp_revs[] = { 0x11, 0x12, 0x13, 0x14 }; + u8 value; + link->caps.alternate_scrambler_reset = true;
+ 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 f9f65bc13df5..13c50e905205 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1405,6 +1405,7 @@ void drm_dp_link_caps_copy(struct drm_dp_link_caps *dest, * @max_rate: maximum clock rate supported on the link * @max_lanes: maximum number of lanes supported on the link * @caps: capabilities supported on the link (see &drm_dp_link_caps) + * @edp: eDP revision (0x11: eDP 1.1, 0x12: eDP 1.2, ...) * @rate: currently configured link rate * @lanes: currently configured number of lanes */ @@ -1414,6 +1415,7 @@ struct drm_dp_link { unsigned int max_lanes;
struct drm_dp_link_caps caps; + unsigned char edp;
unsigned int rate; unsigned int lanes;