[PATCH v2 26/26] drm/bridge: imx8qxp-pixel-link: convert to of_drm_get_bridge()

[Luca Ceresoli]

of_drm_find_bridge() is deprecated. Move to its replacement
of_drm_get_bridge() which gets a bridge reference, and put it when done.

This needs to be handled in various steps:

 * the bridge returned of_drm_get_bridge() is stored in next_bridge whose
   scope is the for loop, so a cleanup action is enough
 * the value of next_bridge is copied into selected_bridge, potentially
   more than once, so a cleanup action at function scope is useful here too
 * however on successful return selected_bridge must be returned and
   ultimately stored, so it should not be put in that case: use
   return_ptr() to defuse the cleanup action on successful return
 * finally, put the bridge reference on device remove

Signed-off-by: Luca Ceresoli <luca.ceresoli at bootlin.com>

---

Cc: Liu Ying <victor.liu at nxp.com>
---
 drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
index 2ecc3c1051e5..4f2f730142ea 100644
--- a/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
+++ b/drivers/gpu/drm/bridge/imx/imx8qxp-pixel-link.c
@@ -256,12 +256,13 @@ static int imx8qxp_pixel_link_disable_all_controls(struct imx8qxp_pixel_link *pl
 	return imx8qxp_pixel_link_disable_sync(pl);
 }
 
+/* The returned bridge has its refcount incremented */
 static struct drm_bridge *
 imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 {
 	struct device_node *np = pl->dev->of_node;
 	struct device_node *port;
-	struct drm_bridge *selected_bridge = NULL;
+	struct drm_bridge *selected_bridge __free(drm_bridge_put) = NULL;
 	u32 port_id;
 	bool found_port = false;
 	int reg;
@@ -298,7 +299,7 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 			continue;
 		}
 
-		struct drm_bridge *next_bridge = of_drm_find_bridge(remote);
+		struct drm_bridge *next_bridge __free(drm_bridge_put) = of_drm_get_bridge(remote);
 		if (!next_bridge)
 			return ERR_PTR(-EPROBE_DEFER);
 
@@ -306,13 +307,15 @@ imx8qxp_pixel_link_find_next_bridge(struct imx8qxp_pixel_link *pl)
 		 * Select the next bridge with companion PXL2DPI if
 		 * present, otherwise default to the first bridge
 		 */
-		if (!selected_bridge || of_property_present(remote, "fsl,companion-pxl2dpi"))
-			selected_bridge = next_bridge;
+		if (!selected_bridge || of_property_present(remote, "fsl,companion-pxl2dpi")) {
+			drm_bridge_put(selected_bridge);
+			selected_bridge = drm_bridge_get(next_bridge);
+		}
 	}
 
 	pl->mst_addr = port_id - 1;
 
-	return selected_bridge;
+	return_ptr(selected_bridge);
 }
 
 static int imx8qxp_pixel_link_bridge_probe(struct platform_device *pdev)
@@ -392,6 +395,7 @@ static void imx8qxp_pixel_link_bridge_remove(struct platform_device *pdev)
 	struct imx8qxp_pixel_link *pl = platform_get_drvdata(pdev);
 
 	drm_bridge_remove(&pl->bridge);
+	drm_bridge_put(pl->next_bridge);
 }
 
 static const struct of_device_id imx8qxp_pixel_link_dt_ids[] = {

-- 
2.51.1