From 93cb4094a7fd30a6e20b9781aafb94e3fffbe59a Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Wed, 17 Apr 2024 01:10:08 +0300 Subject: drm/dp_mst: Add drm_dp_mst_aux_for_parent() Add a function to get the AUX device of the parent of an MST port, used by a follow-up i915 patch in the patchset. v2: Move drm_dp_mst_aux_for_parent() forward declaration to this patch (Ankit) Cc: Lyude Paul Cc: dri-devel@lists.freedesktop.org Reviewed-by: Ankit Nautiyal Acked-by: Maarten Lankhorst Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20240416221010.376865-10-imre.deak@intel.com --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'drivers/gpu/drm/display') diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 46b99d5fe008..3577786b5db2 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -6010,6 +6010,22 @@ static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) return false; } +/** + * drm_dp_mst_aux_for_parent() - Get the AUX device for an MST port's parent + * @port: MST port whose parent's AUX device is returned + * + * Return the AUX device for @port's parent or NULL if port's parent is the + * root port. + */ +struct drm_dp_aux *drm_dp_mst_aux_for_parent(struct drm_dp_mst_port *port) +{ + if (!port->parent || !port->parent->port_parent) + return NULL; + + return &port->parent->port_parent->aux; +} +EXPORT_SYMBOL(drm_dp_mst_aux_for_parent); + /** * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC * @port: The port to check. A leaf of the MST tree with an attached display. -- cgit v1.2.3