[PATCH] Bluetooth: btmtksdio: Lookup device node only as fallback

[Chen-Yu Tsai]

If the device tree is properly written, the SDIO function device node
should be correctly defined, and the mmc core in Linux should correctly
tie it to the device being probed.

Only fall back to searching for the device node by compatible if the
original device node tied to the device is incorrect, as seen in older
device trees.

Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
---
This follows up on the MT7921S bluetooth binding and DT fixup patches [1].
This should not be backported.

[1] https://lore.kernel.org/linux-bluetooth/20240412073046.1192744-1-wenst@chromium.org/

 drivers/bluetooth/btmtksdio.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c
index b4e560a17aa6..d81fa8dacb4e 100644
--- a/drivers/bluetooth/btmtksdio.c
+++ b/drivers/bluetooth/btmtksdio.c
@@ -1330,6 +1330,8 @@ static int btmtksdio_probe(struct sdio_func *func,
 {
 	struct btmtksdio_dev *bdev;
 	struct hci_dev *hdev;
+	struct device_node *old_node;
+	bool restore_node;
 	int err;
 
 	bdev = devm_kzalloc(&func->dev, sizeof(*bdev), GFP_KERNEL);
@@ -1413,13 +1415,24 @@ static int btmtksdio_probe(struct sdio_func *func,
 	if (err)
 		bt_dev_err(hdev, "failed to initialize device wakeup");
 
-	bdev->dev->of_node = of_find_compatible_node(NULL, NULL,
-						     "mediatek,mt7921s-bluetooth");
+	restore_node = false;
+	if (!of_device_is_compatible(bdev->dev->of_node, "mediatek,mt7921s-bluetooth")) {
+		restore_node = true;
+		old_node = bdev->dev->of_node;
+		bdev->dev->of_node = of_find_compatible_node(NULL, NULL,
+							     "mediatek,mt7921s-bluetooth");
+	}
+
 	bdev->reset = devm_gpiod_get_optional(bdev->dev, "reset",
 					      GPIOD_OUT_LOW);
 	if (IS_ERR(bdev->reset))
 		err = PTR_ERR(bdev->reset);
 
+	if (restore_node) {
+		of_node_put(bdev->dev->of_node);
+		bdev->dev->of_node = old_node;
+	}
+
 	return err;
 }
 
-- 
2.45.2.741.gdbec12cfda-goog