[PATCH v2] Input: tca8418_keypad - Add devm cleanup to disable interrupts on unload

[Zhian Liang]

tca8418_configure() enables TCA8418 interrupts by writing the CFG
register.  If input_register_device() fails afterwards, probe returns
an error and devres releases the IRQ handler, but the hardware is
left with interrupts still enabled.

Fix it by registering a devm action that clears the CFG register
 when the device is released, disabling
all interrupts on both probe failure and driver unbind.

Signed-off-by: Zhian Liang <liangzhan5dev@xxxxxxxxx>

---
Changes in v2:
- Fixed typo: tca84818_write_byte -> tca8418_write_byte
- Fixed typo: tca8418_diable_hw -> tca8418_disable_hw
---
 drivers/input/keyboard/tca8418_keypad.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/input/keyboard/tca8418_keypad.c b/drivers/input/keyboard/tca8418_keypad.c
index 36d4a7c38bb1..413b404a08ba 100644
--- a/drivers/input/keyboard/tca8418_keypad.c
+++ b/drivers/input/keyboard/tca8418_keypad.c
@@ -270,6 +270,20 @@ static int tca8418_configure(struct tca8418_keypad *keypad_data,
 	return error;
 }
 
+static void tca8418_disable_hw(void *data)
+{
+	struct tca8418_keypad *keypad_data = data;
+	int error;
+
+	error = tca8418_write_byte(keypad_data, REG_CFG, 0);
+	if (error)
+		dev_warn(&keypad_data->client->dev, "unable to disable interrupts: %d\n", error);
+
+	error = tca8418_write_byte(keypad_data, REG_INT_STAT, 0xff);
+	if (error)
+		dev_warn(&keypad_data->client->dev, "unable to clear interrupt status: %d\n", error);
+}
+
 static int tca8418_keypad_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -356,6 +370,10 @@ static int tca8418_keypad_probe(struct i2c_client *client)
 	if (error < 0)
 		return error;
 
+	error = devm_add_action_or_reset(dev, tca8418_disable_hw, keypad_data);
+	if (error)
+		return error;
+
 	error = input_register_device(input);
 	if (error) {
 		dev_err(dev, "Unable to register input device, error: %d\n",
-- 
2.34.1