drm/imx: parallel-display: convert to devm_drm_bridge_alloc() API

This is the new API for allocating DRM bridges.

This conversion was missed during the initial conversion of all bridges to
the new API. Thus all kernels with commit 94d50c1 ("drm/bridge:
get/put the bridge reference in drm_bridge_attach/detach()") and using this
driver now warn due to drm_bridge_attach() incrementing the refcount, which
is not initialized without using devm_drm_bridge_alloc() for allocation.

To make the conversion simple and straightforward without messing up with
the drmm_simple_encoder_alloc(), move the struct drm_bridge from struct
imx_parallel_display_encoder to struct imx_parallel_display.

Also remove the 'struct imx_parallel_display *pd' from struct
imx_parallel_display_encoder, not needed anymore.

Fixes: 94d50c1 ("drm/bridge: get/put the bridge reference in drm_bridge_attach/detach()")
Reported-by: Ernest Van Hoecke <[email protected]>
Closes: https://lore.kernel.org/all/hlf4wdopapxnh4rekl5s3kvoi6egaga3lrjfbx6r223ar3txri@3ik53xw5idyh/
Signed-off-by: Luca Ceresoli <[email protected]>
Reviewed-by: Louis Chauvet <[email protected]>
Tested-by: Ernest Van Hoecke <[email protected]>
Link: https://patch.msgid.link/20251014-drm-bridge-alloc-imx-ipuv3-v1-1-a1bb1dcbff50@bootlin.com
Signed-off-by: Philipp Zabel <[email protected]>

Author: lucaceresoli

drivers/gpu/drm/imx/ipuv3/parallel-display.c

@@ -25,19 +25,18 @@
 
 struct imx_parallel_display_encoder {
 	struct drm_encoder encoder;
-	struct drm_bridge bridge;
-	struct imx_parallel_display *pd;
 };
 
 struct imx_parallel_display {
 	struct device *dev;
 	u32 bus_format;
 	struct drm_bridge *next_bridge;
+	struct drm_bridge bridge;
 };
 
 static inline struct imx_parallel_display *bridge_to_imxpd(struct drm_bridge *b)
 {
-	return container_of(b, struct imx_parallel_display_encoder, bridge)->pd;
+	return container_of(b, struct imx_parallel_display, bridge);
 }
 
 static const u32 imx_pd_bus_fmts[] = {
@@ -195,15 +194,13 @@ static int imx_pd_bind(struct device *dev, struct device *master, void *data)
 	if (IS_ERR(imxpd_encoder))
 		return PTR_ERR(imxpd_encoder);
 
-	imxpd_encoder->pd = imxpd;
 	encoder = &imxpd_encoder->encoder;
-	bridge = &imxpd_encoder->bridge;
+	bridge = &imxpd->bridge;
 
 	ret = imx_drm_encoder_parse_of(drm, encoder, imxpd->dev->of_node);
 	if (ret)
 		return ret;
 
-	bridge->funcs = &imx_pd_bridge_funcs;
 	drm_bridge_attach(encoder, bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 
 	connector = drm_bridge_connector_init(drm, encoder);
@@ -228,9 +225,10 @@ static int imx_pd_probe(struct platform_device *pdev)
 	u32 bus_format = 0;
 	const char *fmt;
 
-	imxpd = devm_kzalloc(dev, sizeof(*imxpd), GFP_KERNEL);
-	if (!imxpd)
-		return -ENOMEM;
+	imxpd = devm_drm_bridge_alloc(dev, struct imx_parallel_display, bridge,
+				      &imx_pd_bridge_funcs);
+	if (IS_ERR(imxpd))
+		return PTR_ERR(imxpd);
 
 	/* port@1 is the output port */
 	imxpd->next_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);