drm/vc4: convert to devm_drm_bridge_alloc() API

This is the new API for allocating DRM bridges.

This driver already implements refcounting of the struct vc4_dsi, which
embeds struct drm_bridge. Now this is a duplicate of the refcounting
implemented by the DRM bridge core, so convert the vc4_dsi_get/put() calls
into drm_bridge_get/put() calls and get rid of the driver-specific
refcounting implementation.

Signed-off-by: Luca Ceresoli <[email protected]>
Acked-by: Dave Stevenson <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20250424-drm-bridge-convert-to-alloc-api-v2-27-8f91a404d86b@bootlin.com
Signed-off-by: Louis Chauvet <[email protected]>

Author: lucaceresoli

drivers/gpu/drm/vc4/vc4_dsi.c

@@ -552,8 +552,6 @@ struct vc4_dsi {
 	struct vc4_encoder encoder;
 	struct mipi_dsi_host dsi_host;
 
-	struct kref kref;
-
 	struct platform_device *pdev;
 
 	struct drm_bridge *out_bridge;
@@ -1622,29 +1620,11 @@ static void vc4_dsi_dma_chan_release(void *ptr)
 	dsi->reg_dma_chan = NULL;
 }
 
-static void vc4_dsi_release(struct kref *kref)
-{
-	struct vc4_dsi *dsi =
-		container_of(kref, struct vc4_dsi, kref);
-
-	kfree(dsi);
-}
-
-static void vc4_dsi_get(struct vc4_dsi *dsi)
-{
-	kref_get(&dsi->kref);
-}
-
-static void vc4_dsi_put(struct vc4_dsi *dsi)
-{
-	kref_put(&dsi->kref, &vc4_dsi_release);
-}
-
 static void vc4_dsi_release_action(struct drm_device *drm, void *ptr)
 {
 	struct vc4_dsi *dsi = ptr;
 
-	vc4_dsi_put(dsi);
+	drm_bridge_put(&dsi->bridge);
 }
 
 static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
@@ -1655,7 +1635,7 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
 	struct drm_encoder *encoder = &dsi->encoder.base;
 	int ret;
 
-	vc4_dsi_get(dsi);
+	drm_bridge_get(&dsi->bridge);
 
 	ret = drmm_add_action_or_reset(drm, vc4_dsi_release_action, dsi);
 	if (ret)
@@ -1810,15 +1790,12 @@ static int vc4_dsi_dev_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct vc4_dsi *dsi;
 
-	dsi = kzalloc(sizeof(*dsi), GFP_KERNEL);
-	if (!dsi)
-		return -ENOMEM;
+	dsi = devm_drm_bridge_alloc(&pdev->dev, struct vc4_dsi, bridge, &vc4_dsi_bridge_funcs);
+	if (IS_ERR(dsi))
+		return PTR_ERR(dsi);
 	dev_set_drvdata(dev, dsi);
 
-	kref_init(&dsi->kref);
-
 	dsi->pdev = pdev;
-	dsi->bridge.funcs = &vc4_dsi_bridge_funcs;
 #ifdef CONFIG_OF
 	dsi->bridge.of_node = dev->of_node;
 #endif
@@ -1836,7 +1813,6 @@ static void vc4_dsi_dev_remove(struct platform_device *pdev)
 	struct vc4_dsi *dsi = dev_get_drvdata(dev);
 
 	mipi_dsi_host_unregister(&dsi->dsi_host);
-	vc4_dsi_put(dsi);
 }
 
 struct platform_driver vc4_dsi_driver = {