[PATCH] iio: imu: kmx61: Use guard(mutex)() family over manual locking

[Maxwell Doose <m32285159@gmail.com>]

Include linux/cleanup.h to take advantage of new macros.

Replace manual mutex_lock() and mutex_unlock() calls across the file
with guard(mutex)() and scoped_guard() where appropriate. This will help
modernize the driver with up-to-date functions/macros.

Remove now redundant gotos and ret variables, as the new RAII macros
make them unneeded.

Signed-off-by: Maxwell Doose <m32285159@gmail.com>
---
 drivers/iio/imu/kmx61.c | 74 ++++++++++++++---------------------------
 1 file changed, 25 insertions(+), 49 deletions(-)

diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
index 3cd91d8a89ee..2baaca129601 100644
--- a/drivers/iio/imu/kmx61.c
+++ b/drivers/iio/imu/kmx61.c
@@ -7,6 +7,7 @@
  * IIO driver for KMX61 (7-bit I2C slave address 0x0E or 0x0F).
  */
 
+#include <linux/cleanup.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/mod_devicetable.h>
@@ -794,25 +795,21 @@ static int kmx61_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
-		mutex_lock(&data->lock);
+		guard(mutex)(&data->lock);
 
 		ret = kmx61_set_power_state(data, true, chan->address);
-		if (ret) {
-			mutex_unlock(&data->lock);
+		if (ret)
 			return ret;
-		}
 
 		ret = kmx61_read_measurement(data, base_reg, chan->scan_index);
 		if (ret < 0) {
 			kmx61_set_power_state(data, false, chan->address);
-			mutex_unlock(&data->lock);
 			return ret;
 		}
 		*val = sign_extend32(ret >> chan->scan_type.shift,
 				     chan->scan_type.realbits - 1);
 		ret = kmx61_set_power_state(data, false, chan->address);
 
-		mutex_unlock(&data->lock);
 		if (ret)
 			return ret;
 		return IIO_VAL_INT;
@@ -834,9 +831,8 @@ static int kmx61_read_raw(struct iio_dev *indio_dev,
 		if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)
 			return -EINVAL;
 
-		mutex_lock(&data->lock);
-		ret = kmx61_get_odr(data, val, val2, chan->address);
-		mutex_unlock(&data->lock);
+		scoped_guard(mutex, &data->lock)
+			ret = kmx61_get_odr(data, val, val2, chan->address);
 		if (ret)
 			return -EINVAL;
 		return IIO_VAL_INT_PLUS_MICRO;
@@ -856,19 +852,15 @@ static int kmx61_write_raw(struct iio_dev *indio_dev,
 		if (chan->type != IIO_ACCEL && chan->type != IIO_MAGN)
 			return -EINVAL;
 
-		mutex_lock(&data->lock);
-		ret = kmx61_set_odr(data, val, val2, chan->address);
-		mutex_unlock(&data->lock);
-		return ret;
+		guard(mutex)(&data->lock);
+		return kmx61_set_odr(data, val, val2, chan->address);
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
 		case IIO_ACCEL:
 			if (val != 0)
 				return -EINVAL;
-			mutex_lock(&data->lock);
-			ret = kmx61_set_scale(data, val2);
-			mutex_unlock(&data->lock);
-			return ret;
+			guard(mutex)(&data->lock);
+			return kmx61_set_scale(data, val2);
 		default:
 			return -EINVAL;
 		}
@@ -945,28 +937,25 @@ static int kmx61_write_event_config(struct iio_dev *indio_dev,
 	if (state && data->ev_enable_state)
 		return 0;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	if (!state && data->motion_trig_on) {
 		data->ev_enable_state = false;
-		goto err_unlock;
+		return ret;
 	}
 
 	ret = kmx61_set_power_state(data, state, KMX61_ACC);
 	if (ret < 0)
-		goto err_unlock;
+		return ret;
 
 	ret = kmx61_setup_any_motion_interrupt(data, state);
 	if (ret < 0) {
 		kmx61_set_power_state(data, false, KMX61_ACC);
-		goto err_unlock;
+		return ret;
 	}
 
 	data->ev_enable_state = state;
 
-err_unlock:
-	mutex_unlock(&data->lock);
-
 	return ret;
 }
 
@@ -1020,11 +1009,11 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 	struct kmx61_data *data = kmx61_get_data(indio_dev);
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 
 	if (!state && data->ev_enable_state && data->motion_trig_on) {
 		data->motion_trig_on = false;
-		goto err_unlock;
+		return ret;
 	}
 
 	if (data->acc_dready_trig == trig || data->motion_trig == trig)
@@ -1034,7 +1023,7 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 
 	ret = kmx61_set_power_state(data, state, device);
 	if (ret < 0)
-		goto err_unlock;
+		return ret;
 
 	if (data->acc_dready_trig == trig || data->mag_dready_trig == trig)
 		ret = kmx61_setup_new_data_interrupt(data, state, device);
@@ -1042,7 +1031,7 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		ret = kmx61_setup_any_motion_interrupt(data, state);
 	if (ret < 0) {
 		kmx61_set_power_state(data, false, device);
-		goto err_unlock;
+		return ret;
 	}
 
 	if (data->acc_dready_trig == trig)
@@ -1051,8 +1040,6 @@ static int kmx61_data_rdy_trigger_set_state(struct iio_trigger *trig,
 		data->mag_dready_trig_on = state;
 	else
 		data->motion_trig_on = state;
-err_unlock:
-	mutex_unlock(&data->lock);
 
 	return ret;
 }
@@ -1195,19 +1182,17 @@ static irqreturn_t kmx61_trigger_handler(int irq, void *p)
 	else
 		base = KMX61_MAG_XOUT_L;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	iio_for_each_active_channel(indio_dev, bit) {
 		ret = kmx61_read_measurement(data, base, bit);
 		if (ret < 0) {
-			mutex_unlock(&data->lock);
-			goto err;
+			iio_trigger_notify_done(indio_dev->trig);
+			return IRQ_HANDLED;
 		}
 		buffer[i++] = ret;
 	}
-	mutex_unlock(&data->lock);
 
 	iio_push_to_buffers(indio_dev, buffer);
-err:
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;
@@ -1419,22 +1404,17 @@ static void kmx61_remove(struct i2c_client *client)
 		iio_trigger_unregister(data->motion_trig);
 	}
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
-	mutex_unlock(&data->lock);
 }
 
 static int kmx61_suspend(struct device *dev)
 {
-	int ret;
 	struct kmx61_data *data = i2c_get_clientdata(to_i2c_client(dev));
 
-	mutex_lock(&data->lock);
-	ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG,
+	guard(mutex)(&data->lock);
+	return kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG,
 			     false);
-	mutex_unlock(&data->lock);
-
-	return ret;
 }
 
 static int kmx61_resume(struct device *dev)
@@ -1453,13 +1433,9 @@ static int kmx61_resume(struct device *dev)
 static int kmx61_runtime_suspend(struct device *dev)
 {
 	struct kmx61_data *data = i2c_get_clientdata(to_i2c_client(dev));
-	int ret;
-
-	mutex_lock(&data->lock);
-	ret = kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
-	mutex_unlock(&data->lock);
 
-	return ret;
+	guard(mutex)(&data->lock);
+	return kmx61_set_mode(data, KMX61_ALL_STBY, KMX61_ACC | KMX61_MAG, true);
 }
 
 static int kmx61_runtime_resume(struct device *dev)
-- 
2.53.0