The drivers gets probed from a mfd devices. So the driver runs
probe although no DT node exists. This leads to a NULL pointer
dereference in the probe function. Check if a node exists and
error out in case none is present.

Fixes: 3e9f0b3e2b27 ("input: Add MediaTek PMIC keys support")
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 drivers/input/keyboard/mtk-pmic-keys.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/keyboard/mtk-pmic-keys.c b/drivers/input/keyboard/mtk-pmic-keys.c
index 02c67a1749fc..388043e1939c 100644
--- a/drivers/input/keyboard/mtk-pmic-keys.c
+++ b/drivers/input/keyboard/mtk-pmic-keys.c

@@ -257,6 +257,9 @@ static int mtk_pmic_keys_probe(struct platform_device *pdev)
 	const struct of_device_id *of_id =
 		of_match_device(of_mtk_pmic_keys_match_tbl, &pdev->dev);
 
+	if (of_id == NULL)
+		return -ENODEV;
+
 	keys = devm_kzalloc(&pdev->dev, sizeof(*keys), GFP_KERNEL);
 	if (!keys)
 		return -ENOMEM;

-- 
2.17.1