drm/msm: remove extra indirection for msm_mdss

Since now there is just one mdss subdriver, drop all the indirection,
make msm_mdss struct completely opaque (and defined inside msm_mdss.c)
and call mdss functions directly.

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/482505/
Link: https://lore.kernel.org/r/20220419155346.1272627-3-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/msm_drv.c

@@ -1001,8 +1001,8 @@ static int __maybe_unused msm_runtime_suspend(struct device *dev)
 
 	DBG("");
 
-	if (mdss && mdss->funcs)
-		return mdss->funcs->disable(mdss);
+	if (mdss)
+		return msm_mdss_disable(mdss);
 
 	return 0;
 }
@@ -1014,8 +1014,8 @@ static int __maybe_unused msm_runtime_resume(struct device *dev)
 
 	DBG("");
 
-	if (mdss && mdss->funcs)
-		return mdss->funcs->enable(mdss);
+	if (mdss)
+		return msm_mdss_enable(mdss);
 
 	return 0;
 }
@@ -1241,6 +1241,7 @@ static const struct component_master_ops msm_drm_ops = {
 static int msm_pdev_probe(struct platform_device *pdev)
 {
 	struct component_match *match = NULL;
+	struct msm_mdss *mdss;
 	struct msm_drm_private *priv;
 	int ret;
 
@@ -1252,20 +1253,22 @@ static int msm_pdev_probe(struct platform_device *pdev)
 
 	switch (get_mdp_ver(pdev)) {
 	case KMS_MDP5:
-		ret = msm_mdss_init(pdev, true);
+		mdss = msm_mdss_init(pdev, true);
 		break;
 	case KMS_DPU:
-		ret = msm_mdss_init(pdev, false);
+		mdss = msm_mdss_init(pdev, false);
 		break;
 	default:
-		ret = 0;
+		mdss = NULL;
 		break;
 	}
-	if (ret) {
-		platform_set_drvdata(pdev, NULL);
+	if (IS_ERR(mdss)) {
+		ret = PTR_ERR(mdss);
 		return ret;
 	}
 
+	priv->mdss = mdss;
+
 	if (get_mdp_ver(pdev)) {
 		ret = add_display_components(pdev, &match);
 		if (ret)
@@ -1292,8 +1295,8 @@ static int msm_pdev_probe(struct platform_device *pdev)
 fail:
 	of_platform_depopulate(&pdev->dev);
 
-	if (priv->mdss && priv->mdss->funcs)
-		priv->mdss->funcs->destroy(priv->mdss);
+	if (priv->mdss)
+		msm_mdss_destroy(priv->mdss);
 
 	return ret;
 }
@@ -1306,8 +1309,8 @@ static int msm_pdev_remove(struct platform_device *pdev)
 	component_master_del(&pdev->dev, &msm_drm_ops);
 	of_platform_depopulate(&pdev->dev);
 
-	if (mdss && mdss->funcs)
-		mdss->funcs->destroy(mdss);
+	if (mdss)
+		msm_mdss_destroy(mdss);
 
 	return 0;
 }

drivers/gpu/drm/msm/msm_kms.h

@@ -201,18 +201,12 @@ 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);
-	void (*destroy)(struct msm_mdss *mdss);
-};
-
-struct msm_mdss {
-	struct device *dev;
-	const struct msm_mdss_funcs *funcs;
-};
+struct msm_mdss;
 
-int msm_mdss_init(struct platform_device *pdev, bool is_mdp5);
+struct msm_mdss *msm_mdss_init(struct platform_device *pdev, bool is_mdp5);
+int msm_mdss_enable(struct msm_mdss *mdss);
+int msm_mdss_disable(struct msm_mdss *mdss);
+void msm_mdss_destroy(struct msm_mdss *mdss);
 
 #define for_each_crtc_mask(dev, crtc, crtc_mask) \
 	drm_for_each_crtc(crtc, dev) \