Re: [PATCH v6 2/4] drm/msm/dp: parser data-lanes as property of dp_out endpoint

[Dmitry Baryshkov]

On 01/12/2022 01:51, Kuogee Hsieh wrote:

Add capability to parser data-lanes as property of dp_out endpoint.
Also retain the original capability to parser data-lanes as property
of mdss_dp node to handle legacy case.

Changes in v6:
-- first patch after split parser patch into two

Signed-off-by: Kuogee Hsieh <quic_khs...@quicinc.com>
---
  drivers/gpu/drm/msm/dp/dp_parser.c | 30 +++++++++++++++++++++++-------
  1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c 
b/drivers/gpu/drm/msm/dp/dp_parser.c
index dd73221..b06ff60 100644
--- a/drivers/gpu/drm/msm/dp/dp_parser.c
+++ b/drivers/gpu/drm/msm/dp/dp_parser.c
@@ -94,16 +94,32 @@ static int dp_parser_ctrl_res(struct dp_parser *parser)
  static int dp_parser_misc(struct dp_parser *parser)
  {
        struct device_node *of_node = parser->pdev->dev.of_node;
-       int len;
+       struct device_node *endpoint;
+       int cnt;
+
+       /*
+        * legacy code, data-lanes is the property of mdss_dp node
+        */
+       cnt = drm_of_get_data_lanes_count(of_node, 1, DP_MAX_NUM_DP_LANES);
+       if (cnt > 0) {
+               parser->max_dp_lanes = cnt;
+               return 0;
+       }

- len = drm_of_get_data_lanes_count(of_node, 1, DP_MAX_NUM_DP_LANES);

-       if (len < 0) {
-               DRM_WARN("Invalid property \"data-lanes\", default max DP lanes = 
%d\n",
-                        DP_MAX_NUM_DP_LANES);
-               len = DP_MAX_NUM_DP_LANES;
+       /*
+        * data-lanes is the property of dp_out endpoint
+        */
+       endpoint = of_graph_get_endpoint_by_regs(of_node, 1, 0); /* port@1 */
+       if (endpoint) {
+               cnt = of_property_count_u32_elems(endpoint, "data-lanes");

drm_of_get_data_lanes_count(), or better drm_of_get_data_lanes_count_ep().

Also please check new property first, then check the legacy one.

So it would be:

cnt = drm_of_get_data_lanes_count_ep();
if (cnt < 0)
    cnt = drm_of_get_data_lanes_count();
if (cnt < 0) {
    DRM_WARN(...);
    cnt = DP_MAX_NUM_DP_LANES;
}

+               if (cnt < 0)
+                       parser->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes 
*/
+               else
+                       parser->max_dp_lanes = cnt;
+       } else {
+               parser->max_dp_lanes = DP_MAX_NUM_DP_LANES; /* 4 lanes */
        }

- parser->max_dp_lanes = len;

        return 0;
  }

--
With best wishes
Dmitry