[PATCH v3 14/14] drm/msm/dp: Add support for lane mapping configuration

[Dmitry Baryshkov]

On Wed, Aug 20, 2025 at 05:34:56PM +0800, Xiangxu Yin wrote:
> Since max_dp_lanes and max_dp_link_rate are link-specific parameters,
> move their parsing from dp_panel to dp_link for better separation
> of concerns.
>
> Add lane mapping configuration for the DisplayPort (DP) controller on
> the QCS615 platform.

Separate patch

> 
> QCS615 platform requires non-default logical-to-physical lane mapping
> due to its unique hardware routing. Unlike the standard mapping sequence
> <0 1 2 3>, QCS615 uses <3 2 0 1>, which necessitates explicit
> configuration via the data-lanes property in the device tree. This
> ensures correct signal routing between the DP controller and PHY.
> 
> The DP PHY supports polarity inversion (PN swap) but does not support
> lane swapping. Therefore, lane mapping should be handled in the DP
> controller domain using REG_DP_LOGICAL2PHYSICAL_LANE_MAPPING.
> 
> Signed-off-by: Xiangxu Yin <xiangxu.yin at oss.qualcomm.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_ctrl.c  | 10 ++---
>  drivers/gpu/drm/msm/dp/dp_link.c  | 71 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_link.h  |  5 +++
>  drivers/gpu/drm/msm/dp/dp_panel.c | 78 +++++----------------------------------
>  drivers/gpu/drm/msm/dp/dp_panel.h |  3 --
>  5 files changed, 90 insertions(+), 77 deletions(-)
> 

-- 
With best wishes
Dmitry