[PATCH v7 1/3] iio: magnetometer: bmc150_magn: use automated cleanup for mutex
From: Neel Bullywon
Date: Sun Feb 15 2026 - 20:55:27 EST
Use guard() and scoped_guard() to replace manual mutex lock/unlock
calls. This simplifies error handling and ensures RAII-style cleanup.
guard() is used in read_raw, write_raw, trig_reen, trigger_set_state,
suspend, and resume. Case blocks using guard() in read_raw and
write_raw are wrapped in braces at the case label level to ensure
clear scope for the cleanup guards.
scoped_guard() is used in remove and runtime_suspend where a short
mutex-protected scope is needed for a single function call.
The trigger_handler function is left unchanged as mixing guard() with
goto error paths can be fragile.
Signed-off-by: Neel Bullywon <neelb2403@xxxxxxxxx>
---
drivers/iio/magnetometer/bmc150_magn.c | 109 ++++++++++---------------
1 file changed, 41 insertions(+), 68 deletions(-)
diff --git a/drivers/iio/magnetometer/bmc150_magn.c b/drivers/iio/magnetometer/bmc150_magn.c
index 6a73f6e2f1f0..ff6196c86e6b 100644
--- a/drivers/iio/magnetometer/bmc150_magn.c
+++ b/drivers/iio/magnetometer/bmc150_magn.c
@@ -12,6 +12,7 @@
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
+#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/pm.h>
@@ -453,33 +454,29 @@ static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
s32 values[AXIS_XYZ_MAX];
switch (mask) {
- case IIO_CHAN_INFO_RAW:
+ case IIO_CHAN_INFO_RAW: {
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
- mutex_lock(&data->mutex);
+
+ guard(mutex)(&data->mutex);
ret = bmc150_magn_set_power_state(data, true);
- if (ret < 0) {
- mutex_unlock(&data->mutex);
+ if (ret < 0)
return ret;
- }
ret = bmc150_magn_read_xyz(data, values);
if (ret < 0) {
bmc150_magn_set_power_state(data, false);
- mutex_unlock(&data->mutex);
return ret;
}
*val = values[chan->scan_index];
ret = bmc150_magn_set_power_state(data, false);
- if (ret < 0) {
- mutex_unlock(&data->mutex);
+ if (ret < 0)
return ret;
- }
- mutex_unlock(&data->mutex);
return IIO_VAL_INT;
+ }
case IIO_CHAN_INFO_SCALE:
/*
* The API/driver performs an off-chip temperature
@@ -527,48 +524,39 @@ static int bmc150_magn_write_raw(struct iio_dev *indio_dev,
int ret;
switch (mask) {
- case IIO_CHAN_INFO_SAMP_FREQ:
+ case IIO_CHAN_INFO_SAMP_FREQ: {
if (val > data->max_odr)
return -EINVAL;
- mutex_lock(&data->mutex);
- ret = bmc150_magn_set_odr(data, val);
- mutex_unlock(&data->mutex);
- return ret;
+ guard(mutex)(&data->mutex);
+ return bmc150_magn_set_odr(data, val);
+ }
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
switch (chan->channel2) {
case IIO_MOD_X:
- case IIO_MOD_Y:
+ case IIO_MOD_Y: {
if (val < 1 || val > 511)
return -EINVAL;
- mutex_lock(&data->mutex);
+ guard(mutex)(&data->mutex);
ret = bmc150_magn_set_max_odr(data, val, 0, 0);
- if (ret < 0) {
- mutex_unlock(&data->mutex);
+ if (ret < 0)
return ret;
- }
- ret = regmap_update_bits(data->regmap,
+ return regmap_update_bits(data->regmap,
BMC150_MAGN_REG_REP_XY,
BMC150_MAGN_REG_REP_DATAMASK,
- BMC150_MAGN_REPXY_TO_REGVAL
- (val));
- mutex_unlock(&data->mutex);
- return ret;
- case IIO_MOD_Z:
+ BMC150_MAGN_REPXY_TO_REGVAL(val));
+ }
+ case IIO_MOD_Z: {
if (val < 1 || val > 256)
return -EINVAL;
- mutex_lock(&data->mutex);
+ guard(mutex)(&data->mutex);
ret = bmc150_magn_set_max_odr(data, 0, val, 0);
- if (ret < 0) {
- mutex_unlock(&data->mutex);
+ if (ret < 0)
return ret;
- }
- ret = regmap_update_bits(data->regmap,
+ return regmap_update_bits(data->regmap,
BMC150_MAGN_REG_REP_Z,
BMC150_MAGN_REG_REP_DATAMASK,
- BMC150_MAGN_REPZ_TO_REGVAL
- (val));
- mutex_unlock(&data->mutex);
- return ret;
+ BMC150_MAGN_REPZ_TO_REGVAL(val));
+ }
default:
return -EINVAL;
}
@@ -782,9 +770,8 @@ static void bmc150_magn_trig_reen(struct iio_trigger *trig)
if (!data->dready_trigger_on)
return;
- mutex_lock(&data->mutex);
+ guard(mutex)(&data->mutex);
ret = bmc150_magn_reset_intr(data);
- mutex_unlock(&data->mutex);
if (ret)
dev_err(data->dev, "Failed to reset interrupt\n");
}
@@ -794,32 +781,28 @@ static int bmc150_magn_data_rdy_trigger_set_state(struct iio_trigger *trig,
{
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct bmc150_magn_data *data = iio_priv(indio_dev);
- int ret = 0;
+ int ret;
+
+ guard(mutex)(&data->mutex);
- mutex_lock(&data->mutex);
if (state == data->dready_trigger_on)
- goto err_unlock;
+ return 0;
ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_INT_DRDY,
BMC150_MAGN_MASK_DRDY_EN,
state << BMC150_MAGN_SHIFT_DRDY_EN);
if (ret < 0)
- goto err_unlock;
+ return ret;
data->dready_trigger_on = state;
if (state) {
ret = bmc150_magn_reset_intr(data);
if (ret < 0)
- goto err_unlock;
+ return ret;
}
- mutex_unlock(&data->mutex);
return 0;
-
-err_unlock:
- mutex_unlock(&data->mutex);
- return ret;
}
static const struct iio_trigger_ops bmc150_magn_trigger_ops = {
@@ -980,9 +963,8 @@ void bmc150_magn_remove(struct device *dev)
if (data->dready_trig)
iio_trigger_unregister(data->dready_trig);
- mutex_lock(&data->mutex);
- bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex)
+ bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
}
@@ -995,10 +977,9 @@ static int bmc150_magn_runtime_suspend(struct device *dev)
struct bmc150_magn_data *data = iio_priv(indio_dev);
int ret;
- mutex_lock(&data->mutex);
- ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
- true);
- mutex_unlock(&data->mutex);
+ scoped_guard(mutex, &data->mutex)
+ ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
+ true);
if (ret < 0) {
dev_err(dev, "powering off device failed\n");
return ret;
@@ -1024,28 +1005,20 @@ static int bmc150_magn_suspend(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct bmc150_magn_data *data = iio_priv(indio_dev);
- int ret;
-
- mutex_lock(&data->mutex);
- ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
- true);
- mutex_unlock(&data->mutex);
- return ret;
+ guard(mutex)(&data->mutex);
+ return bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
+ true);
}
static int bmc150_magn_resume(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct bmc150_magn_data *data = iio_priv(indio_dev);
- int ret;
-
- mutex_lock(&data->mutex);
- ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
- true);
- mutex_unlock(&data->mutex);
- return ret;
+ guard(mutex)(&data->mutex);
+ return bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
+ true);
}
#endif
--
2.44.0