Re: [PATCH 5/8] drm/msm/dp: Add support for lane mapping configuration

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On Fri, 29 Nov 2024 at 09:59, Xiangxu Yin <quic_xiangxuy@xxxxxxxxxxx> wrote:
>
> Add the ability to configure lane mapping for the DP controller. This is
> required when the platform's lane mapping does not follow the default
> order (0, 1, 2, 3). The mapping rules are now configurable via the
> `data-lane` property in the devicetree. This property defines the
> logical-to-physical lane mapping sequence, ensuring correct lane
> assignment for non-default configurations.
>
> Signed-off-by: Xiangxu Yin <quic_xiangxuy@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dp/dp_catalog.c | 11 +++++------
>  drivers/gpu/drm/msm/dp/dp_catalog.h |  2 +-
>  drivers/gpu/drm/msm/dp/dp_ctrl.c    |  2 +-
>  drivers/gpu/drm/msm/dp/dp_panel.c   | 13 ++++++++++---
>  drivers/gpu/drm/msm/dp/dp_panel.h   |  3 +++
>  5 files changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
> index b4c8856fb25d01dd1b30c5ec33ce821aafa9551d..34439d0709d2e1437e5669fd0b995936420ee16f 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> @@ -361,17 +361,16 @@ void msm_dp_catalog_ctrl_config_ctrl(struct msm_dp_catalog *msm_dp_catalog, u32
>         msm_dp_write_link(catalog, REG_DP_CONFIGURATION_CTRL, cfg);
>  }
>
> -void msm_dp_catalog_ctrl_lane_mapping(struct msm_dp_catalog *msm_dp_catalog)
> +void msm_dp_catalog_ctrl_lane_mapping(struct msm_dp_catalog *msm_dp_catalog, u32 *l_map)

lane_map, not l_map.

>  {
>         struct msm_dp_catalog_private *catalog = container_of(msm_dp_catalog,
>                                 struct msm_dp_catalog_private, msm_dp_catalog);
> -       u32 ln_0 = 0, ln_1 = 1, ln_2 = 2, ln_3 = 3; /* One-to-One mapping */
>         u32 ln_mapping;
>
> -       ln_mapping = ln_0 << LANE0_MAPPING_SHIFT;
> -       ln_mapping |= ln_1 << LANE1_MAPPING_SHIFT;
> -       ln_mapping |= ln_2 << LANE2_MAPPING_SHIFT;
> -       ln_mapping |= ln_3 << LANE3_MAPPING_SHIFT;
> +       ln_mapping = l_map[0] << LANE0_MAPPING_SHIFT;
> +       ln_mapping |= l_map[1] << LANE1_MAPPING_SHIFT;
> +       ln_mapping |= l_map[2] << LANE2_MAPPING_SHIFT;
> +       ln_mapping |= l_map[3] << LANE3_MAPPING_SHIFT;
>
>         msm_dp_write_link(catalog, REG_DP_LOGICAL2PHYSICAL_LANE_MAPPING,
>                         ln_mapping);
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
> index e932b17eecbf514070cd8cd0b98ca0fefbe81ab7..8b8de2a7d3ad561c1901e1bdaad92d4fab12e808 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.h
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
> @@ -69,7 +69,7 @@ u32 msm_dp_catalog_aux_get_irq(struct msm_dp_catalog *msm_dp_catalog);
>  /* DP Controller APIs */
>  void msm_dp_catalog_ctrl_state_ctrl(struct msm_dp_catalog *msm_dp_catalog, u32 state);
>  void msm_dp_catalog_ctrl_config_ctrl(struct msm_dp_catalog *msm_dp_catalog, u32 config);
> -void msm_dp_catalog_ctrl_lane_mapping(struct msm_dp_catalog *msm_dp_catalog);
> +void msm_dp_catalog_ctrl_lane_mapping(struct msm_dp_catalog *msm_dp_catalog, u32 *l_map);
>  void msm_dp_catalog_ctrl_mainlink_ctrl(struct msm_dp_catalog *msm_dp_catalog, bool enable);
>  void msm_dp_catalog_ctrl_psr_mainlink_enable(struct msm_dp_catalog *msm_dp_catalog, bool enable);
>  void msm_dp_catalog_setup_peripheral_flush(struct msm_dp_catalog *msm_dp_catalog);
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index bc2ca8133b790fc049e18ab3b37a629558664dd4..49c8ce9b2d0e57a613e50865be3fe98e814d425a 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -177,7 +177,7 @@ static void msm_dp_ctrl_configure_source_params(struct msm_dp_ctrl_private *ctrl
>  {
>         u32 cc, tb;
>
> -       msm_dp_catalog_ctrl_lane_mapping(ctrl->catalog);
> +       msm_dp_catalog_ctrl_lane_mapping(ctrl->catalog, ctrl->panel->lane_map);
>         msm_dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, true);
>         msm_dp_catalog_setup_peripheral_flush(ctrl->catalog);
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
> index 5d7eaa31bf3176566f40f01ff636bee64e81c64f..8654180aa259234bbd41f4f88c13c485f9791b1d 100644
> --- a/drivers/gpu/drm/msm/dp/dp_panel.c
> +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
> @@ -11,7 +11,6 @@
>  #include <drm/drm_of.h>
>  #include <drm/drm_print.h>
>
> -#define DP_MAX_NUM_DP_LANES    4
>  #define DP_LINK_RATE_HBR2      540000 /* kbytes */
>
>  struct msm_dp_panel_private {
> @@ -461,6 +460,7 @@ static int msm_dp_panel_parse_dt(struct msm_dp_panel *msm_dp_panel)
>         struct msm_dp_panel_private *panel;
>         struct device_node *of_node;
>         int cnt;
> +       u32 lane_map[DP_MAX_NUM_DP_LANES] = {0, 1, 2, 3};
>
>         panel = container_of(msm_dp_panel, struct msm_dp_panel_private, msm_dp_panel);
>         of_node = panel->dev->of_node;
> @@ -474,10 +474,17 @@ static int msm_dp_panel_parse_dt(struct msm_dp_panel *msm_dp_panel)
>                 cnt = drm_of_get_data_lanes_count(of_node, 1, DP_MAX_NUM_DP_LANES);
>         }
>
> -       if (cnt > 0)
> +       if (cnt > 0) {
> +               struct device_node *endpoint;
> +
>                 msm_dp_panel->max_dp_lanes = cnt;
> -       else
> +               endpoint = of_graph_get_endpoint_by_regs(of_node, 1, -1);
> +               of_property_read_u32_array(endpoint, "data-lanes", lane_map, cnt);
> +       } else {
>                 msm_dp_panel->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes */
> +       }

Why? This sounds more like dp_catalog or (after the refactoring at
[1]) dp_ctrl. But not the dp_panel.

[1] https://patchwork.freedesktop.org/project/freedreno/series/?ordering=-last_updated

> +
> +       memcpy(msm_dp_panel->lane_map, lane_map, msm_dp_panel->max_dp_lanes * sizeof(u32));
>
>         msm_dp_panel->max_dp_link_rate = msm_dp_panel_link_frequencies(of_node);
>         if (!msm_dp_panel->max_dp_link_rate)
> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
> index 0e944db3adf2f187f313664fe80cf540ec7a19f2..7603b92c32902bd3d4485539bd6308537ff75a2c 100644
> --- a/drivers/gpu/drm/msm/dp/dp_panel.h
> +++ b/drivers/gpu/drm/msm/dp/dp_panel.h
> @@ -11,6 +11,8 @@
>  #include "dp_aux.h"
>  #include "dp_link.h"
>
> +#define DP_MAX_NUM_DP_LANES    4
> +
>  struct edid;
>
>  struct msm_dp_display_mode {
> @@ -46,6 +48,7 @@ struct msm_dp_panel {
>         bool video_test;
>         bool vsc_sdp_supported;
>
> +       u32 lane_map[DP_MAX_NUM_DP_LANES];
>         u32 max_dp_lanes;
>         u32 max_dp_link_rate;
>
>
> --
> 2.25.1
>


-- 
With best wishes
Dmitry