[PATCH 05/29] iio: adc: ti-ads1015: Use guard(mutex) and factor out code for INFO_RAW

[Jonathan Cameron <jic23@kernel.org>]

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

By use of automatic lock release and introducing a new utility
function to handle the core activity of reading the ADC channel,
many more complex code flows can be replaced by direct returns.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Vasut <marex@denx.de>
---
 drivers/iio/adc/ti-ads1015.c | 162 ++++++++++++++---------------------
 1 file changed, 64 insertions(+), 98 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 4355726b373a..a91ec18ddbec 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/module.h>
+#include <linux/cleanup.h>
 #include <linux/init.h>
 #include <linux/irq.h>
 #include <linux/i2c.h>
@@ -533,6 +534,31 @@ static int ads1015_read_avail(struct iio_dev *indio_dev,
 	}
 }
 
+static int __ads1015_read_info_raw(struct ads1015_data *data,
+				   struct iio_chan_spec const *chan, int *val)
+{
+	int ret;
+
+	if (ads1015_event_channel_enabled(data) &&
+	    data->event_channel != chan->address)
+		return -EBUSY;
+
+	ret = ads1015_set_power_state(data, true);
+	if (ret < 0)
+		return ret;
+
+	ret = ads1015_get_adc_result(data, chan->address, val);
+	if (ret < 0) {
+		ads1015_set_power_state(data, false);
+		return ret;
+	}
+
+	*val = sign_extend32(*val >> chan->scan_type.shift,
+			     chan->scan_type.realbits - 1);
+
+	return ads1015_set_power_state(data, false);
+}
+
 static int ads1015_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan, int *val,
 			    int *val2, long mask)
@@ -540,58 +566,30 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
 	int ret, idx;
 	struct ads1015_data *data = iio_priv(indio_dev);
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		ret = iio_device_claim_direct_mode(indio_dev);
 		if (ret)
-			break;
-
-		if (ads1015_event_channel_enabled(data) &&
-				data->event_channel != chan->address) {
-			ret = -EBUSY;
-			goto release_direct;
-		}
-
-		ret = ads1015_set_power_state(data, true);
-		if (ret < 0)
-			goto release_direct;
-
-		ret = ads1015_get_adc_result(data, chan->address, val);
-		if (ret < 0) {
-			ads1015_set_power_state(data, false);
-			goto release_direct;
-		}
-
-		*val = sign_extend32(*val >> chan->scan_type.shift,
-				     chan->scan_type.realbits - 1);
-
-		ret = ads1015_set_power_state(data, false);
-		if (ret < 0)
-			goto release_direct;
-
-		ret = IIO_VAL_INT;
-release_direct:
+			return ret;
+		ret = __ads1015_read_info_raw(data, chan, val);
 		iio_device_release_direct_mode(indio_dev);
-		break;
+		if (ret)
+			return ret;
+
+		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		idx = data->channel_data[chan->address].pga;
 		*val = ads1015_fullscale_range[idx];
 		*val2 = chan->scan_type.realbits - 1;
-		ret = IIO_VAL_FRACTIONAL_LOG2;
-		break;
+		return IIO_VAL_FRACTIONAL_LOG2;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		idx = data->channel_data[chan->address].data_rate;
 		*val = data->chip->data_rate[idx];
-		ret = IIO_VAL_INT;
-		break;
+		return IIO_VAL_INT;
 	default:
-		ret = -EINVAL;
-		break;
+		return -EINVAL;
 	}
-	mutex_unlock(&data->lock);
-
-	return ret;
 }
 
 static int ads1015_write_raw(struct iio_dev *indio_dev,
@@ -599,23 +597,16 @@ static int ads1015_write_raw(struct iio_dev *indio_dev,
 			     int val2, long mask)
 {
 	struct ads1015_data *data = iio_priv(indio_dev);
-	int ret;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
-		ret = ads1015_set_scale(data, chan, val, val2);
-		break;
+		return ads1015_set_scale(data, chan, val, val2);
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		ret = ads1015_set_data_rate(data, chan->address, val);
-		break;
+		return ads1015_set_data_rate(data, chan->address, val);
 	default:
-		ret = -EINVAL;
-		break;
+		return -EINVAL;
 	}
-	mutex_unlock(&data->lock);
-
-	return ret;
 }
 
 static int ads1015_read_event(struct iio_dev *indio_dev,
@@ -624,20 +615,18 @@ static int ads1015_read_event(struct iio_dev *indio_dev,
 	int *val2)
 {
 	struct ads1015_data *data = iio_priv(indio_dev);
-	int ret;
 	unsigned int comp_queue;
 	int period;
 	int dr;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	switch (info) {
 	case IIO_EV_INFO_VALUE:
 		*val = (dir == IIO_EV_DIR_RISING) ?
 			data->thresh_data[chan->address].high_thresh :
 			data->thresh_data[chan->address].low_thresh;
-		ret = IIO_VAL_INT;
-		break;
+		return IIO_VAL_INT;
 	case IIO_EV_INFO_PERIOD:
 		dr = data->channel_data[chan->address].data_rate;
 		comp_queue = data->thresh_data[chan->address].comp_queue;
@@ -646,16 +635,10 @@ static int ads1015_read_event(struct iio_dev *indio_dev,
 
 		*val = period / USEC_PER_SEC;
 		*val2 = period % USEC_PER_SEC;
-		ret = IIO_VAL_INT_PLUS_MICRO;
-		break;
+		return IIO_VAL_INT_PLUS_MICRO;
 	default:
-		ret = -EINVAL;
-		break;
+		return -EINVAL;
 	}
-
-	mutex_unlock(&data->lock);
-
-	return ret;
 }
 
 static int ads1015_write_event(struct iio_dev *indio_dev,
@@ -666,24 +649,22 @@ static int ads1015_write_event(struct iio_dev *indio_dev,
 	struct ads1015_data *data = iio_priv(indio_dev);
 	const int *data_rate = data->chip->data_rate;
 	int realbits = chan->scan_type.realbits;
-	int ret = 0;
 	long long period;
 	int i;
 	int dr;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	switch (info) {
 	case IIO_EV_INFO_VALUE:
-		if (val >= 1 << (realbits - 1) || val < -1 << (realbits - 1)) {
-			ret = -EINVAL;
-			break;
-		}
+		if (val >= 1 << (realbits - 1) || val < -1 << (realbits - 1))
+			return -EINVAL;
+
 		if (dir == IIO_EV_DIR_RISING)
 			data->thresh_data[chan->address].high_thresh = val;
 		else
 			data->thresh_data[chan->address].low_thresh = val;
-		break;
+		return 0;
 	case IIO_EV_INFO_PERIOD:
 		dr = data->channel_data[chan->address].data_rate;
 		period = val * USEC_PER_SEC + val2;
@@ -694,15 +675,10 @@ static int ads1015_write_event(struct iio_dev *indio_dev,
 				break;
 		}
 		data->thresh_data[chan->address].comp_queue = i;
-		break;
+		return 0;
 	default:
-		ret = -EINVAL;
-		break;
+		return -EINVAL;
 	}
-
-	mutex_unlock(&data->lock);
-
-	return ret;
 }
 
 static int ads1015_read_event_config(struct iio_dev *indio_dev,
@@ -710,25 +686,19 @@ static int ads1015_read_event_config(struct iio_dev *indio_dev,
 	enum iio_event_direction dir)
 {
 	struct ads1015_data *data = iio_priv(indio_dev);
-	int ret = 0;
 
-	mutex_lock(&data->lock);
-	if (data->event_channel == chan->address) {
-		switch (dir) {
-		case IIO_EV_DIR_RISING:
-			ret = 1;
-			break;
-		case IIO_EV_DIR_EITHER:
-			ret = (data->comp_mode == ADS1015_CFG_COMP_MODE_WINDOW);
-			break;
-		default:
-			ret = -EINVAL;
-			break;
-		}
-	}
-	mutex_unlock(&data->lock);
+	guard(mutex)(&data->lock);
+	if (data->event_channel != chan->address)
+		return -EBUSY;
 
-	return ret;
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		return 1;
+	case IIO_EV_DIR_EITHER:
+		return (data->comp_mode == ADS1015_CFG_COMP_MODE_WINDOW);
+	default:
+		return -EINVAL;
+	}
 }
 
 static int ads1015_enable_event_config(struct ads1015_data *data,
@@ -813,14 +783,12 @@ static int ads1015_write_event_config(struct iio_dev *indio_dev,
 	int comp_mode = (dir == IIO_EV_DIR_EITHER) ?
 		ADS1015_CFG_COMP_MODE_WINDOW : ADS1015_CFG_COMP_MODE_TRAD;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	/* Prevent from enabling both buffer and event at a time */
 	ret = iio_device_claim_direct_mode(indio_dev);
-	if (ret) {
-		mutex_unlock(&data->lock);
+	if (ret)
 		return ret;
-	}
 
 	if (state)
 		ret = ads1015_enable_event_config(data, chan, comp_mode);
@@ -828,8 +796,6 @@ static int ads1015_write_event_config(struct iio_dev *indio_dev,
 		ret = ads1015_disable_event_config(data, chan, comp_mode);
 
 	iio_device_release_direct_mode(indio_dev);
-	mutex_unlock(&data->lock);
-
 	return ret;
 }
 
-- 
2.48.1