diff options
| -rw-r--r-- | drivers/gpu/drm/drm_dp_helper.c | 12 | ||||
| -rw-r--r-- | include/drm/drm_dp_helper.h | 2 |
2 files changed, 14 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 57c61d126a56..7b3a638725d9 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -513,6 +513,18 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], } EXPORT_SYMBOL(drm_dp_downstream_max_bpc); +/** + * drm_dp_downstream_id() - identify branch device + * @aux: DisplayPort AUX channel + * + * Returns branch device id on success or NULL on failure + */ +int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]) +{ + return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6); +} +EXPORT_SYMBOL(drm_dp_downstream_id); + /* * I2C-over-AUX implementation */ diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index f3d14240338e..faea76bec514 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -445,6 +445,7 @@ #define DP_SOURCE_OUI 0x300 #define DP_SINK_OUI 0x400 #define DP_BRANCH_OUI 0x500 +#define DP_BRANCH_ID 0x503 #define DP_SET_POWER 0x600 # define DP_SET_POWER_D0 0x1 @@ -819,6 +820,7 @@ int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]); int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE], const u8 port_cap[4]); +int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6]); void drm_dp_aux_init(struct drm_dp_aux *aux); int drm_dp_aux_register(struct drm_dp_aux *aux); |