[PATCH v3 6/7] iio: light: opt3001: move driver to guard(mutex)() use

[Joshua Crofts via B4 Relay <devnull+joshua.crofts1.gmail.com@kernel.org>]

From: Joshua Crofts <joshua.crofts1@gmail.com>

Move driver to use guard(mutex)() macro, to facilitate automatic
locking/unlocking of resources. This modernizes the driver and
improves code style.

While at it, remove unnecessary gotos and return variables.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Joshua Crofts <joshua.crofts1@gmail.com>
---
 drivers/iio/light/opt3001.c | 140 +++++++++++++++++++-------------------------
 1 file changed, 60 insertions(+), 80 deletions(-)

diff --git a/drivers/iio/light/opt3001.c b/drivers/iio/light/opt3001.c
index d5262488dac889066a53d3234762e0557f9e3cbc..ac1c7ba5679867f6b814894680e317615f2e373b 100644
--- a/drivers/iio/light/opt3001.c
+++ b/drivers/iio/light/opt3001.c
@@ -10,6 +10,7 @@
 
 #include <linux/array_size.h>
 #include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/dev_printk.h>
 #include <linux/errno.h>
@@ -477,7 +478,6 @@ static int opt3001_read_raw(struct iio_dev *iio,
 			    int *val, int *val2, long mask)
 {
 	struct opt3001 *opt = iio_priv(iio);
-	int ret;
 
 	if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 		return -EBUSY;
@@ -485,23 +485,17 @@ static int opt3001_read_raw(struct iio_dev *iio,
 	if (chan->type != opt->chip_info->chan_type)
 		return -EINVAL;
 
-	mutex_lock(&opt->lock);
+	guard(mutex)(&opt->lock);
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 	case IIO_CHAN_INFO_PROCESSED:
-		ret = opt3001_get_processed(opt, val, val2);
-		break;
+		return opt3001_get_processed(opt, val, val2);
 	case IIO_CHAN_INFO_INT_TIME:
-		ret = opt3001_get_int_time(opt, val, val2);
-		break;
+		return opt3001_get_int_time(opt, val, val2);
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 	}
-
-	mutex_unlock(&opt->lock);
-
-	return ret;
 }
 
 static int opt3001_write_raw(struct iio_dev *iio,
@@ -509,7 +503,6 @@ static int opt3001_write_raw(struct iio_dev *iio,
 			     int val, int val2, long mask)
 {
 	struct opt3001 *opt = iio_priv(iio);
-	int ret;
 
 	if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
 		return -EBUSY;
@@ -523,11 +516,9 @@ static int opt3001_write_raw(struct iio_dev *iio,
 	if (val != 0)
 		return -EINVAL;
 
-	mutex_lock(&opt->lock);
-	ret = opt3001_set_int_time(opt, val2);
-	mutex_unlock(&opt->lock);
+	guard(mutex)(&opt->lock);
 
-	return ret;
+	return opt3001_set_int_time(opt, val2);
 }
 
 static int opt3001_read_event_value(struct iio_dev *iio,
@@ -538,28 +529,23 @@ static int opt3001_read_event_value(struct iio_dev *iio,
 				    int *val, int *val2)
 {
 	struct opt3001 *opt = iio_priv(iio);
-	int ret = IIO_VAL_INT_PLUS_MICRO;
 
-	mutex_lock(&opt->lock);
+	guard(mutex)(&opt->lock);
 
 	switch (dir) {
 	case IIO_EV_DIR_RISING:
 		opt3001_to_iio_ret(opt, opt->high_thresh_exp,
 				   opt->high_thresh_mantissa,
 				   val, val2);
-		break;
+		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_EV_DIR_FALLING:
 		opt3001_to_iio_ret(opt, opt->low_thresh_exp,
 				   opt->low_thresh_mantissa,
 				   val, val2);
-		break;
+		return IIO_VAL_INT_PLUS_MICRO;
 	default:
-		ret = -EINVAL;
+		return -EINVAL;
 	}
-
-	mutex_unlock(&opt->lock);
-
-	return ret;
 }
 
 static int opt3001_write_event_value(struct iio_dev *iio,
@@ -586,12 +572,12 @@ static int opt3001_write_event_value(struct iio_dev *iio,
 	if (val < 0)
 		return -EINVAL;
 
-	mutex_lock(&opt->lock);
+	guard(mutex)(&opt->lock);
 
 	ret = opt3001_find_scale(opt, val, val2, &exponent);
 	if (ret < 0) {
 		dev_err(dev, "can't find scale for %d.%06u\n", val, val2);
-		goto err;
+		return ret;
 	}
 
 	whole = opt->chip_info->factor_whole;
@@ -614,20 +600,16 @@ static int opt3001_write_event_value(struct iio_dev *iio,
 		opt->low_thresh_exp = exponent;
 		break;
 	default:
-		ret = -EINVAL;
-		goto err;
+		return -EINVAL;
 	}
 
 	ret = i2c_smbus_write_word_swapped(client, reg, value);
 	if (ret < 0) {
 		dev_err(dev, "failed to write register %02x\n", reg);
-		goto err;
+		return ret;
 	}
 
-err:
-	mutex_unlock(&opt->lock);
-
-	return ret;
+	return 0;
 }
 
 static int opt3001_read_event_config(struct iio_dev *iio,
@@ -659,7 +641,7 @@ static int opt3001_write_event_config(struct iio_dev *iio,
 	if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN)
 		return 0;
 
-	mutex_lock(&opt->lock);
+	guard(mutex)(&opt->lock);
 
 	mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS
 		: OPT3001_CONFIGURATION_M_SHUTDOWN;
@@ -668,7 +650,7 @@ static int opt3001_write_event_config(struct iio_dev *iio,
 	if (ret < 0) {
 		dev_err(dev, "failed to read register %02x\n",
 			OPT3001_CONFIGURATION);
-		goto err;
+		return ret;
 	}
 
 	reg = ret;
@@ -678,13 +660,10 @@ static int opt3001_write_event_config(struct iio_dev *iio,
 	if (ret < 0) {
 		dev_err(dev, "failed to write register %02x\n",
 			OPT3001_CONFIGURATION);
-		goto err;
+		return ret;
 	}
 
-err:
-	mutex_unlock(&opt->lock);
-
-	return ret;
+	return 0;
 }
 
 static const struct iio_info opt3001_info = {
@@ -726,6 +705,31 @@ static int opt3001_read_id(struct opt3001 *opt)
 	return 0;
 }
 
+static void opt3001_power_off(void *data)
+{
+	struct opt3001 *opt = data;
+	struct i2c_client *client = opt->client;
+	struct device *dev = opt->dev;
+	u16 reg_val;
+	int ret;
+
+	ret = i2c_smbus_read_word_swapped(client, OPT3001_CONFIGURATION);
+	if (ret < 0) {
+		dev_err(dev, "failed to read register %02x\n",
+			OPT3001_CONFIGURATION);
+		return;
+	}
+
+	reg_val = ret;
+	opt3001_set_mode(opt, &reg_val, OPT3001_CONFIGURATION_M_SHUTDOWN);
+
+	ret = i2c_smbus_write_word_swapped(client, OPT3001_CONFIGURATION,
+					   reg_val);
+	if (ret < 0)
+		dev_err(dev, "failed to write to register %02x\n",
+			OPT3001_CONFIGURATION);
+}
+
 static int opt3001_configure(struct opt3001 *opt)
 {
 	struct i2c_client *client = opt->client;
@@ -764,6 +768,11 @@ static int opt3001_configure(struct opt3001 *opt)
 		return dev_err_probe(dev, ret, "failed to write register %02x\n",
 				     OPT3001_CONFIGURATION);
 
+	ret = devm_add_action_or_reset(dev, opt3001_power_off, opt);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to register power off function\n");
+
 	ret = i2c_smbus_read_word_swapped(client, OPT3001_LOW_LIMIT);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "failed to read register %02x\n",
@@ -857,7 +866,10 @@ static int opt3001_probe(struct i2c_client *client)
 	opt->client = client;
 	opt->chip_info = i2c_get_match_data(client);
 
-	mutex_init(&opt->lock);
+	ret = devm_mutex_init(dev, &opt->lock);
+	if (ret)
+		return ret;
+
 	init_waitqueue_head(&opt->result_ready_queue);
 	i2c_set_clientdata(client, iio);
 
@@ -879,49 +891,18 @@ static int opt3001_probe(struct i2c_client *client)
 
 	/* Make use of INT pin only if valid IRQ no. is given */
 	if (irq > 0) {
-		ret = request_threaded_irq(irq, NULL, opt3001_irq,
-					   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
-					   "opt3001", iio);
+		ret = devm_request_threaded_irq(dev, irq, NULL, opt3001_irq,
+						IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+						"opt3001", iio);
 		if (ret)
-			return dev_err_probe(dev, ret,
-					     "failed to request IRQ #%d\n",
-					     irq);
+			return ret;
+
 		opt->use_irq = true;
 	} else {
 		dev_dbg(dev, "enabling interrupt-less operation\n");
 	}
 
-	return iio_device_register(iio);
-}
-
-static void opt3001_remove(struct i2c_client *client)
-{
-	struct iio_dev *iio = i2c_get_clientdata(client);
-	struct opt3001 *opt = iio_priv(iio);
-	struct device *dev = &client->dev;
-	int ret;
-	u16 reg;
-
-	iio_device_unregister(iio);
-
-	if (opt->use_irq)
-		free_irq(client->irq, iio);
-
-	ret = i2c_smbus_read_word_swapped(client, OPT3001_CONFIGURATION);
-	if (ret < 0) {
-		dev_err(dev, "failed to read register %02x\n",
-			OPT3001_CONFIGURATION);
-		return;
-	}
-
-	reg = ret;
-	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
-
-	ret = i2c_smbus_write_word_swapped(client, OPT3001_CONFIGURATION, reg);
-	if (ret < 0) {
-		dev_err(dev, "failed to write register %02x\n",
-			OPT3001_CONFIGURATION);
-	}
+	return devm_iio_device_register(dev, iio);
 }
 
 static const struct opt3001_chip_info opt3001_chip_information = {
@@ -962,7 +943,6 @@ MODULE_DEVICE_TABLE(of, opt3001_of_match);
 
 static struct i2c_driver opt3001_driver = {
 	.probe = opt3001_probe,
-	.remove = opt3001_remove,
 	.id_table = opt3001_id,
 
 	.driver = {

-- 
2.47.3