drm/dp/mst: Sideband message transaction to power up/down nodes
The POWER_DOWN_PHY and POWER_UP_PHY sideband message transactions allow
the source to reqest any node in a mst path or a whole path to be
powered down or up. This allows drivers to target a specific sink in the
MST topology, an improvement over just power managing the imediate
downstream device. Secondly, since the request-reply protocol waits for an
ACK, we can be sure that a downstream sink has enough time to respond to a
power up/down request.
v2: Fix memory leak (Lyude)
Cc: Lyude <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170907001458.9399-1-dhinakaran.pandiyan@intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index d55abb7..7f78d26 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -631,5 +631,7 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,
int slots);
+int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
+ struct drm_dp_mst_port *port, bool power_up);
#endif