drm/bridge: chrontel-ch7033: switch to of_drm_get_bridge_by_endpoint()

This driver calls drm_of_find_panel_or_bridge() with a NULL pointer in the
@panel parameter, thus using a reduced feature set of that function.
Replace this call with the simpler of_drm_get_bridge_by_endpoint().

Since of_drm_get_bridge_by_endpoint() increases the refcount of the
returned bridge, ensure it is put on removal. To achieve this, instead of
adding an explicit drm_bridge_put(), migrate to the bridge::next_bridge
pointer which is automatically put when the bridge is eventually freed.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260511-drm-bridge-alloc-getput-panel_or_bridge-v6-5-f61c9e498b3f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

1 files changed, 13 insertions, 15 deletions

diff --git a/drivers/gpu/drm/bridge/chrontel-ch7033.c b/drivers/gpu/drm/bridge/chrontel-ch7033.c
index 54d49d4882c8..a237c65ebd69 100644
--- a/drivers/gpu/drm/bridge/chrontel-ch7033.c
+++ b/drivers/gpu/drm/bridge/chrontel-ch7033.c
@@ -199,7 +199,6 @@ enum {
 
 struct ch7033_priv {
 	struct regmap *regmap;
-	struct drm_bridge *next_bridge;
 	struct drm_bridge bridge;
 	struct drm_connector connector;
 };
@@ -215,7 +214,7 @@ static enum drm_connector_status ch7033_connector_detect(
 {
 	struct ch7033_priv *priv = conn_to_ch7033_priv(connector);
 
-	return drm_bridge_detect(priv->next_bridge, connector);
+	return drm_bridge_detect(priv->bridge.next_bridge, connector);
 }
 
 static const struct drm_connector_funcs ch7033_connector_funcs = {
@@ -233,7 +232,7 @@ static int ch7033_connector_get_modes(struct drm_connector *connector)
 	const struct drm_edid *drm_edid;
 	int ret;
 
-	drm_edid = drm_bridge_edid_read(priv->next_bridge, connector);
+	drm_edid = drm_bridge_edid_read(priv->bridge.next_bridge, connector);
 	drm_edid_connector_update(connector, drm_edid);
 	if (drm_edid) {
 		ret = drm_edid_connector_add_modes(connector);
@@ -275,7 +274,7 @@ static int ch7033_bridge_attach(struct drm_bridge *bridge,
 	struct drm_connector *connector = &priv->connector;
 	int ret;
 
-	ret = drm_bridge_attach(encoder, priv->next_bridge, bridge,
+	ret = drm_bridge_attach(encoder, priv->bridge.next_bridge, bridge,
 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret)
 		return ret;
@@ -283,15 +282,15 @@ static int ch7033_bridge_attach(struct drm_bridge *bridge,
 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
 		return 0;
 
-	if (priv->next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
+	if (priv->bridge.next_bridge->ops & DRM_BRIDGE_OP_DETECT) {
 		connector->polled = DRM_CONNECTOR_POLL_HPD;
 	} else {
 		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
 				    DRM_CONNECTOR_POLL_DISCONNECT;
 	}
 
-	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD) {
-		drm_bridge_hpd_enable(priv->next_bridge, ch7033_hpd_event,
+	if (priv->bridge.next_bridge->ops & DRM_BRIDGE_OP_HPD) {
+		drm_bridge_hpd_enable(priv->bridge.next_bridge, ch7033_hpd_event,
 				      priv);
 	}
 
@@ -299,8 +298,8 @@ static int ch7033_bridge_attach(struct drm_bridge *bridge,
 				 &ch7033_connector_helper_funcs);
 	ret = drm_connector_init_with_ddc(bridge->dev, &priv->connector,
 					  &ch7033_connector_funcs,
-					  priv->next_bridge->type,
-					  priv->next_bridge->ddc);
+					  priv->bridge.next_bridge->type,
+					  priv->bridge.next_bridge->ddc);
 	if (ret) {
 		DRM_ERROR("Failed to initialize connector\n");
 		return ret;
@@ -313,8 +312,8 @@ static void ch7033_bridge_detach(struct drm_bridge *bridge)
 {
 	struct ch7033_priv *priv = bridge_to_ch7033_priv(bridge);
 
-	if (priv->next_bridge->ops & DRM_BRIDGE_OP_HPD)
-		drm_bridge_hpd_disable(priv->next_bridge);
+	if (priv->bridge.next_bridge->ops & DRM_BRIDGE_OP_HPD)
+		drm_bridge_hpd_disable(priv->bridge.next_bridge);
 	drm_connector_cleanup(&priv->connector);
 }
 
@@ -543,10 +542,9 @@ static int ch7033_probe(struct i2c_client *client)
 
 	dev_set_drvdata(dev, priv);
 
-	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, NULL,
-					  &priv->next_bridge);
-	if (ret)
-		return ret;
+	priv->bridge.next_bridge = of_drm_get_bridge_by_endpoint(dev->of_node, 1, -1);
+	if (IS_ERR(priv->bridge.next_bridge))
+		return PTR_ERR(priv->bridge.next_bridge);
 
 	priv->regmap = devm_regmap_init_i2c(client, &ch7033_regmap_config);
 	if (IS_ERR(priv->regmap)) {