summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/drm_dp_helper.c
diff options
context:
space:
mode:
authorMika Kahola <mika.kahola@intel.com>2016-09-09 14:10:51 +0300
committerJani Nikula <jani.nikula@intel.com>2016-09-15 14:50:11 +0300
commit266d783baaf5f34a5bea3b56489f091451a89767 (patch)
tree759ed36c1c0d179c820d39b03b0eb5975bde3be1 /drivers/gpu/drm/drm_dp_helper.c
parent7529d6af1cd16b0ecd286a1bf6ceee5328ab9809 (diff)
downloadlinux-266d783baaf5f34a5bea3b56489f091451a89767.tar.bz2
drm: Read DP branch device id
Read DisplayPort branch device id string. Reviewed-by: Jim Bride <jim.bride@linux.intel.com> Signed-off-by: Mika Kahola <mika.kahola@intel.com> Acked-by: Dave Airlie <airlied@gmail.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1473419458-17080-6-git-send-email-mika.kahola@intel.com
Diffstat (limited to 'drivers/gpu/drm/drm_dp_helper.c')
-rw-r--r--drivers/gpu/drm/drm_dp_helper.c12
1 files changed, 12 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
*/