drm/msm: use compatible lists to find mdp node

In the current implementation, substring comparison
using device node name is used to find mdp node
during driver probe. Use compatible string list instead
of node name to get mdp node from the parent mdss node.
Signed-off-by: Krishna Manikandan <quic_mkrishn@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Changes in v2:
  - Use compatible lists instead of duplicate string
    check (Stephen Boyd)

Changes in v3:
  - Use match tables to find the mdp node (Stephen Boyd)

Changes in v4:
  - Drop EXPORT_SYMBOL (Dmitry Baryshkov)
Link: https://lore.kernel.org/r/1636541507-5144-1-git-send-email-quic_mkrishn@quicinc.comSigned-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c

@@ -1285,7 +1285,7 @@ static const struct dev_pm_ops dpu_pm_ops = {
 				pm_runtime_force_resume)
 };
 
-static const struct of_device_id dpu_dt_match[] = {
+const struct of_device_id dpu_dt_match[] = {
 	{ .compatible = "qcom,sdm845-dpu", },
 	{ .compatible = "qcom,sc7180-dpu", },
 	{ .compatible = "qcom,sc7280-dpu", },

drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c

@@ -1016,7 +1016,7 @@ static const struct dev_pm_ops mdp5_pm_ops = {
 	SET_RUNTIME_PM_OPS(mdp5_runtime_suspend, mdp5_runtime_resume, NULL)
 };
 
-static const struct of_device_id mdp5_dt_match[] = {
+const struct of_device_id mdp5_dt_match[] = {
 	{ .compatible = "qcom,mdp5", },
 	/* to support downstream DT files */
 	{ .compatible = "qcom,mdss_mdp", },

drivers/gpu/drm/msm/msm_drv.c

@@ -1286,9 +1286,10 @@ static int add_components_mdp(struct device *mdp_dev,
 	return 0;
 }
 
-static int compare_name_mdp(struct device *dev, void *data)
+static int find_mdp_node(struct device *dev, void *data)
 {
-	return (strstr(dev_name(dev), "mdp") != NULL);
+	return of_match_node(dpu_dt_match, dev->of_node) ||
+		of_match_node(mdp5_dt_match, dev->of_node);
 }
 
 static int add_display_components(struct platform_device *pdev,
@@ -1313,7 +1314,7 @@ static int add_display_components(struct platform_device *pdev,
 			return ret;
 		}
 
-		mdp_dev = device_find_child(dev, NULL, compare_name_mdp);
+		mdp_dev = device_find_child(dev, NULL, find_mdp_node);
 		if (!mdp_dev) {
 			DRM_DEV_ERROR(dev, "failed to find MDSS MDP node\n");
 			of_platform_depopulate(dev);

drivers/gpu/drm/msm/msm_kms.h

@@ -198,6 +198,9 @@ struct msm_kms *mdp4_kms_init(struct drm_device *dev);
 struct msm_kms *mdp5_kms_init(struct drm_device *dev);
 struct msm_kms *dpu_kms_init(struct drm_device *dev);
 
+extern const struct of_device_id dpu_dt_match[];
+extern const struct of_device_id mdp5_dt_match[];
+
 struct msm_mdss_funcs {
 	int (*enable)(struct msm_mdss *mdss);
 	int (*disable)(struct msm_mdss *mdss);