[PATCH v4 2/6] iio: light: stk3310: handle all remove logic with devm callbacks

[Aren Moynihan <aren@peacevolution.org>]

Using devm callbacks helps to make the ordering of probe / remove
operations easier to reason about and removes some duplicate code
between the probe error path and driver remove.
---

Notes:
    Changes in v4:
     - also replace mutex_init with devm_mutex_init
    
    Added in v3

 drivers/iio/light/stk3310.c | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
index ed20b6714546..181b7acb3f96 100644
--- a/drivers/iio/light/stk3310.c
+++ b/drivers/iio/light/stk3310.c
@@ -484,6 +484,17 @@ static int stk3310_set_state(struct stk3310_data *data, u8 state)
 	return ret;
 }
 
+static void stk3310_set_state_disable(void *private)
+{
+	int ret;
+	struct stk3310_data *data = private;
+	struct device *dev = &data->client->dev;
+
+	ret = stk3310_set_state(data, STK3310_STATE_STANDBY);
+	if (ret)
+		dev_err(dev, "failed to set state to standby: %d\n", ret);
+}
+
 static int stk3310_init(struct iio_dev *indio_dev)
 {
 	int ret;
@@ -491,6 +502,7 @@ static int stk3310_init(struct iio_dev *indio_dev)
 	u8 state;
 	struct stk3310_data *data = iio_priv(indio_dev);
 	struct i2c_client *client = data->client;
+	struct device *dev = &client->dev;
 
 	ret = regmap_read(data->regmap, STK3310_REG_ID, &chipid);
 	if (ret < 0)
@@ -507,6 +519,10 @@ static int stk3310_init(struct iio_dev *indio_dev)
 		return ret;
 	}
 
+	ret = devm_add_action_or_reset(&client->dev, stk3310_set_state_disable, data);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register cleanup function\n");
+
 	/* Enable PS interrupts */
 	ret = regmap_field_write(data->reg_int_ps, STK3310_PSINT_EN);
 	if (ret < 0)
@@ -624,7 +640,7 @@ static int stk3310_probe(struct i2c_client *client)
 	device_property_read_u32(&client->dev, "proximity-near-level",
 				 &data->ps_near_level);
 
-	mutex_init(&data->lock);
+	devm_mutex_init(&client->dev, &data->lock);
 
 	ret = stk3310_regmap_init(data);
 	if (ret < 0)
@@ -650,29 +666,17 @@ static int stk3310_probe(struct i2c_client *client)
 		if (ret < 0) {
 			dev_err(&client->dev, "request irq %d failed\n",
 				client->irq);
-			goto err_standby;
+			return ret;
 		}
 	}
 
-	ret = iio_device_register(indio_dev);
+	ret = devm_iio_device_register(&client->dev, indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "device_register failed\n");
-		goto err_standby;
+		return ret;
 	}
 
 	return 0;
-
-err_standby:
-	stk3310_set_state(data, STK3310_STATE_STANDBY);
-	return ret;
-}
-
-static void stk3310_remove(struct i2c_client *client)
-{
-	struct iio_dev *indio_dev = i2c_get_clientdata(client);
-
-	iio_device_unregister(indio_dev);
-	stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
 }
 
 static int stk3310_suspend(struct device *dev)
@@ -736,7 +740,6 @@ static struct i2c_driver stk3310_driver = {
 		.acpi_match_table = stk3310_acpi_id,
 	},
 	.probe =        stk3310_probe,
-	.remove =           stk3310_remove,
 	.id_table =         stk3310_i2c_id,
 };
 
-- 
2.47.0