Re: [PATCH 19/45] drm/msm/dp: add support to program mst support in mainlink

[Dmitry Baryshkov]

On Thu, Dec 05, 2024 at 08:31:50PM -0800, Abhinav Kumar wrote:
> Add support to program the MST enabled bit in the mainlink
> control when a mst session is active and disabled.
> 
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dp/dp_catalog.c | 17 +++++++++++++++++
>  drivers/gpu/drm/msm/dp/dp_catalog.h |  1 +
>  drivers/gpu/drm/msm/dp/dp_ctrl.c    |  4 ++++
>  3 files changed, 22 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
> index 88d6262a972ef2d30c467ef5ff5c58ef3299ae7d..bdc66e5cab640c351708ba1a1bc3bca21784df6e 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> @@ -417,6 +417,23 @@ void msm_dp_catalog_ctrl_psr_mainlink_enable(struct msm_dp_catalog *msm_dp_catal
>  	msm_dp_write_link(catalog, REG_DP_MAINLINK_CTRL, val);
>  }
>  
> +void msm_dp_catalog_mst_config(struct msm_dp_catalog *msm_dp_catalog, bool enable)

Can this be merged into msm_dp_catalog_ctrl_mainlink_ctrl() ? Or is that
function called too early, when we do not know yet if we need MST or
not?

> +{
> +	struct msm_dp_catalog_private *catalog = container_of(msm_dp_catalog,
> +							      struct msm_dp_catalog_private,
> +							      msm_dp_catalog);
> +
> +	u32 mainlink_ctrl;
> +
> +	mainlink_ctrl = msm_dp_read_link(catalog, REG_DP_MAINLINK_CTRL);
> +	if (enable)
> +		mainlink_ctrl |= (0x04000100);
> +	else
> +		mainlink_ctrl &= ~(0x04000100);

#define

> +
> +	msm_dp_write_link(catalog, REG_DP_MAINLINK_CTRL, mainlink_ctrl);
> +}
> +
>  void msm_dp_catalog_ctrl_mainlink_ctrl(struct msm_dp_catalog *msm_dp_catalog,
>  						bool enable)
>  {
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
> index c91c52d40209b8bcb63db9c0256f6ef721dace8a..07284f484e2861aeae12b115cd05a94afed1c9cb 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.h
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
> @@ -138,5 +138,6 @@ void msm_dp_catalog_audio_sfe_level(struct msm_dp_catalog *catalog, u32 safe_to_
>  /* DP MST APIs */
>  void msm_dp_catalog_trigger_act(struct msm_dp_catalog *dp_catalog);
>  bool msm_dp_catalog_read_act_complete_sts(struct msm_dp_catalog *dp_catalog);
> +void msm_dp_catalog_mst_config(struct msm_dp_catalog *dp_catalog, bool enable);
>  
>  #endif /* _DP_CATALOG_H_ */
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index 2bfe2aac3c02b02b12713dbd98e79ed4a75b85d0..3839f1e8e1aeb2a14a7f59c546693141a0df6323 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -186,6 +186,9 @@ static void msm_dp_ctrl_configure_source_params(struct msm_dp_ctrl_private *ctrl
>  	msm_dp_catalog_ctrl_lane_mapping(ctrl->catalog);
>  	msm_dp_catalog_setup_peripheral_flush(ctrl->catalog);
>  
> +	if (ctrl->mst_active)
> +		msm_dp_catalog_mst_config(ctrl->catalog, true);
> +
>  	msm_dp_ctrl_config_ctrl(ctrl, msm_dp_panel);
>  
>  	tb = msm_dp_link_get_test_bits_depth(ctrl->link,
> @@ -2132,6 +2135,7 @@ void msm_dp_ctrl_off_link(struct msm_dp_ctrl *msm_dp_ctrl)
>  	phy = ctrl->phy;
>  
>  	msm_dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, false);
> +	msm_dp_catalog_mst_config(ctrl->catalog, false);
>  
>  	ctrl->mst_active = false;
>  
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry