From: Thierry Reding <tred...@nvidia.com>
If the sink support eDP, read the eDP revision from it's DPCD.
Signed-off-by: Thierry Reding <treding at nvidia.com>
---
drivers/gpu/drm/drm_dp_helper.c | 30 +++++++++++++++++++++++++++++-
include/drm/drm_dp_helper.h | 1 +
2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 1fe181525604..c711b690508b 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -295,7 +295,7 @@ EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
*/
int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link)
{
- u8 values[7];
+ u8 values[16], value;
int err;
memset(link, 0, sizeof(*link));
@@ -323,6 +323,34 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct
drm_dp_link *link)
if (values[6] & DP_SET_ANSI_8B10B)
link->capabilities |= DP_LINK_CAP_ANSI_8B10B;
+ if (values[13] & DP_ALTERNATE_SCRAMBLER_RESET_CAP) {
+ err = drm_dp_dpcd_readb(aux, DP_EDP_DPCD_REV, &value);
+ if (err < 0)
+ return err;
+
+ switch (value) {
+ case DP_EDP_11:
+ link->edp = 0x11;
+ break;
+
+ case DP_EDP_12:
+ link->edp = 0x12;
+ break;
+
+ case DP_EDP_13:
+ link->edp = 0x13;
+ break;
+
+ case DP_EDP_14:
+ link->edp = 0x14;
+ break;
+
+ default:
+ DRM_ERROR("unsupported eDP version: %02x\n", value);
+ break;
+ }
+ }
+
return 0;
}
EXPORT_SYMBOL(drm_dp_link_probe);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 9e70ea8b907d..f9e7f484a225 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -749,6 +749,7 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
struct drm_dp_link {
unsigned char revision;
+ unsigned char edp;
unsigned int rate;
unsigned int num_lanes;
unsigned long capabilities;
--
2.4.5
