[PATCH v4 16/25] drm/tilcdc: Modernize driver initialization and cleanup paths

[Kory Maincent (TI.com)]

Refactor the driver initialization to use modern DRM managed resource
APIs, simplifying the code.

The tilcdc_init and tilcdc_fini wrapper functions are removed since they
served no purpose after the component framework was eliminated. Their
logic is integrated directly into probe and remove.

Key changes:
- Use devm_drm_dev_alloc() instead of drm_dev_alloc().
- Use drmm_mode_config_init() instead of drm_mode_config_init().
- Align the remove path with the probe error path to ensure consistent
  cleanup ordering in both success and failure cases.
- Adjust platform_set_drvdata() to store the private structure instead
  of the drm_device, matching the new allocation pattern.

These changes reduce error-prone code while maintaining the same
functional behavior.

Signed-off-by: Kory Maincent (TI.com) <kory.maincent at bootlin.com>
---

Change in v3:
- Split the patch between code move and cleanup for better diff
  readibility.
---
 drivers/gpu/drm/tilcdc/tilcdc_drv.c | 100 ++++++++++++------------------------
 drivers/gpu/drm/tilcdc/tilcdc_drv.h |   2 +
 2 files changed, 35 insertions(+), 67 deletions(-)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index abe432b752dc0..2f35075b663ff 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -259,68 +259,33 @@ static int tilcdc_pm_resume(struct device *dev)
 static DEFINE_SIMPLE_DEV_PM_OPS(tilcdc_pm_ops,
 				tilcdc_pm_suspend, tilcdc_pm_resume);
 
-static void tilcdc_fini(struct drm_device *dev)
-{
-	struct tilcdc_drm_private *priv = dev->dev_private;
-
-#ifdef CONFIG_CPU_FREQ
-	if (priv->freq_transition.notifier_call)
-		cpufreq_unregister_notifier(&priv->freq_transition,
-					    CPUFREQ_TRANSITION_NOTIFIER);
-#endif
-
-	if (priv->crtc)
-		tilcdc_crtc_shutdown(priv->crtc);
-
-	drm_dev_unregister(dev);
-
-	drm_kms_helper_poll_fini(dev);
-	drm_atomic_helper_shutdown(dev);
-	tilcdc_irq_uninstall(dev);
-	drm_mode_config_cleanup(dev);
-
-	if (priv->clk)
-		clk_put(priv->clk);
-
-	if (priv->wq)
-		destroy_workqueue(priv->wq);
-
-	dev->dev_private = NULL;
-
-	pm_runtime_disable(dev->dev);
-
-	drm_dev_put(dev);
-}
-
-static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev)
+static int tilcdc_pdev_probe(struct platform_device *pdev)
 {
-	struct drm_device *ddev;
-	struct platform_device *pdev = to_platform_device(dev);
-	struct device_node *node = dev->of_node;
+	struct device_node *node = pdev->dev.of_node;
 	struct tilcdc_drm_private *priv;
+	struct device *dev = &pdev->dev;
 	enum tilcdc_variant variant;
+	struct drm_device *ddev;
 	u32 bpp = 0;
 	int ret;
 
-	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-
-	ddev = drm_dev_alloc(ddrv, dev);
-	if (IS_ERR(ddev))
-		return PTR_ERR(ddev);
+	priv = devm_drm_dev_alloc(dev, &tilcdc_driver,
+				  struct tilcdc_drm_private, ddev);
+	if (IS_ERR(priv))
+		return PTR_ERR(priv);
 
 	variant = (uintptr_t)of_device_get_match_data(dev);
 
 	ddev->dev_private = priv;
-	platform_set_drvdata(pdev, ddev);
-	drm_mode_config_init(ddev);
+	platform_set_drvdata(pdev, priv);
+	ddev = &priv->ddev;
+	ret = drmm_mode_config_init(ddev);
+	if (ret)
+		return ret;
 
 	priv->wq = alloc_ordered_workqueue("tilcdc", 0);
-	if (!priv->wq) {
-		ret = -ENOMEM;
-		goto put_drm;
-	}
+	if (!priv->wq)
+		return -ENOMEM;
 
 	priv->mmio = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->mmio)) {
@@ -486,33 +451,34 @@ static int tilcdc_init(const struct drm_driver *ddrv, struct device *dev)
 	clk_put(priv->clk);
 free_wq:
 	destroy_workqueue(priv->wq);
-put_drm:
-	platform_set_drvdata(pdev, NULL);
-	ddev->dev_private = NULL;
-	drm_dev_put(ddev);
 
 	return ret;
 }
 
-static int tilcdc_pdev_probe(struct platform_device *pdev)
-{
-	/* bail out early if no DT data: */
-	if (!pdev->dev.of_node) {
-		dev_err(&pdev->dev, "device-tree data is missing\n");
-		return -ENXIO;
-	}
-
-	return tilcdc_init(&tilcdc_driver, &pdev->dev);
-}
-
 static void tilcdc_pdev_remove(struct platform_device *pdev)
 {
-	tilcdc_fini(platform_get_drvdata(pdev));
+	struct tilcdc_drm_private *priv = platform_get_drvdata(pdev);
+	struct drm_device *ddev = &priv->ddev;
+
+	drm_dev_unregister(ddev);
+	drm_kms_helper_poll_fini(ddev);
+	tilcdc_irq_uninstall(ddev);
+#ifdef CONFIG_CPU_FREQ
+	cpufreq_unregister_notifier(&priv->freq_transition,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+#endif
+	tilcdc_crtc_destroy(priv->crtc);
+	pm_runtime_disable(&pdev->dev);
+	clk_put(priv->clk);
+	destroy_workqueue(priv->wq);
 }
 
 static void tilcdc_pdev_shutdown(struct platform_device *pdev)
 {
-	drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
+	struct tilcdc_drm_private *priv = platform_get_drvdata(pdev);
+	struct drm_device *ddev = &priv->ddev;
+
+	drm_atomic_helper_shutdown(ddev);
 }
 
 static const struct of_device_id tilcdc_of_match[] = {
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
index 60e85e29b1063..e3d04a3eb25b4 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
@@ -48,6 +48,8 @@ struct tilcdc_drm_private {
 
 	unsigned int irq;
 
+	struct drm_device ddev;
+
 	/* don't attempt resolutions w/ higher W * H * Hz: */
 	uint32_t max_bandwidth;
 	/*

-- 
2.43.0