[PATCH v2 4/4] iio: accel: sca3000: convert to guard(mutex)
From: Rajveer Chaudhari
Date: Mon Mar 09 2026 - 11:41:52 EST
Replace manual mutex_lock/mutex_unlock pair with guard(mutex) in
sca3000_print_rev(), sca3000_ring_int_process(),
sca3000_read_event_config(), __sca3000_hw_ring_state_set(),
sca3000_hw_ring_preenable(), sca3000_hw_ring_postdisable(),
sca3000_clean_setup(), sca3000_stop_all_interrupts().
This ensures the mutex is released on all return paths and
allows returning directly without a goto label.
Signed-off-by: Rajveer Chaudhari <rajveer.chaudhari.linux@xxxxxxxxx>
---
v2: Dropped Header alignment change
---
drivers/iio/accel/sca3000.c | 97 ++++++++++++++++---------------------
1 file changed, 42 insertions(+), 55 deletions(-)
diff --git a/drivers/iio/accel/sca3000.c b/drivers/iio/accel/sca3000.c
index 4a827be439a2..8a06602ab41c 100644
--- a/drivers/iio/accel/sca3000.c
+++ b/drivers/iio/accel/sca3000.c
@@ -9,6 +9,7 @@
#include <linux/interrupt.h>
#include <linux/fs.h>
+#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/kernel.h>
@@ -424,16 +425,16 @@ static int sca3000_print_rev(struct iio_dev *indio_dev)
int ret;
struct sca3000_state *st = iio_priv(indio_dev);
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
+
ret = sca3000_read_data_short(st, SCA3000_REG_REVID_ADDR, 1);
if (ret < 0)
- goto error_ret;
+ return ret;
+
dev_info(&indio_dev->dev,
"sca3000 revision major=%lu, minor=%lu\n",
st->rx[0] & SCA3000_REG_REVID_MAJOR_MASK,
st->rx[0] & SCA3000_REG_REVID_MINOR_MASK);
-error_ret:
- mutex_unlock(&st->lock);
return ret;
}
@@ -996,13 +997,14 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
struct sca3000_state *st = iio_priv(indio_dev);
int ret, i, num_available;
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
if (val & SCA3000_REG_INT_STATUS_HALF) {
ret = sca3000_read_data_short(st, SCA3000_REG_BUF_COUNT_ADDR,
1);
if (ret)
- goto error_ret;
+ return;
+
num_available = st->rx[0];
/*
* num_available is the total number of samples available
@@ -1011,7 +1013,8 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
ret = sca3000_read_data(st, SCA3000_REG_RING_OUT_ADDR, st->rx,
num_available * 2);
if (ret)
- goto error_ret;
+ return;
+
for (i = 0; i < num_available / 3; i++) {
/*
* Dirty hack to cover for 11 bit in fifo, 13 bit
@@ -1023,8 +1026,6 @@ static void sca3000_ring_int_process(u8 val, struct iio_dev *indio_dev)
iio_push_to_buffers(indio_dev, st->rx + i * 3 * 2);
}
}
-error_ret:
- mutex_unlock(&st->lock);
}
/**
@@ -1110,11 +1111,11 @@ static int sca3000_read_event_config(struct iio_dev *indio_dev,
struct sca3000_state *st = iio_priv(indio_dev);
int ret;
/* read current value of mode register */
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
if (ret)
- goto error_ret;
+ return ret;
switch (chan->channel2) {
case IIO_MOD_X_AND_Y_AND_Z:
@@ -1134,7 +1135,7 @@ static int sca3000_read_event_config(struct iio_dev *indio_dev,
ret = sca3000_read_ctrl_reg(st,
SCA3000_REG_CTRL_SEL_MD_CTRL);
if (ret < 0)
- goto error_ret;
+ return ret;
/* only supporting logical or's for now */
ret = !!(ret & sca3000_addresses[chan->address][2]);
}
@@ -1143,9 +1144,6 @@ static int sca3000_read_event_config(struct iio_dev *indio_dev,
ret = -EINVAL;
}
-error_ret:
- mutex_unlock(&st->lock);
-
return ret;
}
@@ -1277,10 +1275,12 @@ int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state)
struct sca3000_state *st = iio_priv(indio_dev);
int ret;
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
+
ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
if (ret)
- goto error_ret;
+ return ret;
+
if (state) {
dev_info(&indio_dev->dev, "supposedly enabling ring buffer\n");
ret = sca3000_write_reg(st,
@@ -1290,8 +1290,6 @@ int __sca3000_hw_ring_state_set(struct iio_dev *indio_dev, bool state)
ret = sca3000_write_reg(st,
SCA3000_REG_MODE_ADDR,
(st->rx[0] & ~SCA3000_REG_MODE_RING_BUF_ENABLE));
-error_ret:
- mutex_unlock(&st->lock);
return ret;
}
@@ -1310,26 +1308,20 @@ static int sca3000_hw_ring_preenable(struct iio_dev *indio_dev)
int ret;
struct sca3000_state *st = iio_priv(indio_dev);
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
/* Enable the 50% full interrupt */
ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
if (ret)
- goto error_unlock;
+ return ret;
+
ret = sca3000_write_reg(st,
SCA3000_REG_INT_MASK_ADDR,
st->rx[0] | SCA3000_REG_INT_MASK_RING_HALF);
if (ret)
- goto error_unlock;
-
- mutex_unlock(&st->lock);
+ return ret;
return __sca3000_hw_ring_state_set(indio_dev, 1);
-
-error_unlock:
- mutex_unlock(&st->lock);
-
- return ret;
}
static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)
@@ -1342,17 +1334,15 @@ static int sca3000_hw_ring_postdisable(struct iio_dev *indio_dev)
return ret;
/* Disable the 50% full interrupt */
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
if (ret)
- goto unlock;
- ret = sca3000_write_reg(st,
+ return ret;
+
+ return sca3000_write_reg(st,
SCA3000_REG_INT_MASK_ADDR,
st->rx[0] & ~SCA3000_REG_INT_MASK_RING_HALF);
-unlock:
- mutex_unlock(&st->lock);
- return ret;
}
static const struct iio_buffer_setup_ops sca3000_ring_setup_ops = {
@@ -1372,25 +1362,26 @@ static int sca3000_clean_setup(struct sca3000_state *st)
{
int ret;
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
+
/* Ensure all interrupts have been acknowledged */
ret = sca3000_read_data_short(st, SCA3000_REG_INT_STATUS_ADDR, 1);
if (ret)
- goto error_ret;
+ return ret;
/* Turn off all motion detection channels */
ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL);
if (ret < 0)
- goto error_ret;
+ return ret;
ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_MD_CTRL,
ret & SCA3000_MD_CTRL_PROT_MASK);
if (ret)
- goto error_ret;
+ return ret;
/* Disable ring buffer */
ret = sca3000_read_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL);
if (ret < 0)
- goto error_ret;
+ return ret;
ret = sca3000_write_ctrl_reg(st, SCA3000_REG_CTRL_SEL_OUT_CTRL,
(ret & SCA3000_REG_OUT_CTRL_PROT_MASK)
| SCA3000_REG_OUT_CTRL_BUF_X_EN
@@ -1398,17 +1389,17 @@ static int sca3000_clean_setup(struct sca3000_state *st)
| SCA3000_REG_OUT_CTRL_BUF_Z_EN
| SCA3000_REG_OUT_CTRL_BUF_DIV_4);
if (ret)
- goto error_ret;
+ return ret;
/* Enable interrupts, relevant to mode and set up as active low */
ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
if (ret)
- goto error_ret;
+ return ret;
ret = sca3000_write_reg(st,
SCA3000_REG_INT_MASK_ADDR,
(ret & SCA3000_REG_INT_MASK_PROT_MASK)
| SCA3000_REG_INT_MASK_ACTIVE_LOW);
if (ret)
- goto error_ret;
+ return ret;
/*
* Select normal measurement mode, free fall off, ring off
* Ring in 12 bit mode - it is fine to overwrite reserved bits 3,5
@@ -1416,13 +1407,10 @@ static int sca3000_clean_setup(struct sca3000_state *st)
*/
ret = sca3000_read_data_short(st, SCA3000_REG_MODE_ADDR, 1);
if (ret)
- goto error_ret;
- ret = sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,
- (st->rx[0] & SCA3000_MODE_PROT_MASK));
+ return ret;
-error_ret:
- mutex_unlock(&st->lock);
- return ret;
+ return sca3000_write_reg(st, SCA3000_REG_MODE_ADDR,
+ (st->rx[0] & SCA3000_MODE_PROT_MASK));
}
static const struct iio_info sca3000_info = {
@@ -1504,18 +1492,17 @@ static int sca3000_stop_all_interrupts(struct sca3000_state *st)
{
int ret;
- mutex_lock(&st->lock);
+ guard(mutex)(&st->lock);
+
ret = sca3000_read_data_short(st, SCA3000_REG_INT_MASK_ADDR, 1);
if (ret)
- goto error_ret;
- ret = sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR,
+ return ret;
+
+ return sca3000_write_reg(st, SCA3000_REG_INT_MASK_ADDR,
(st->rx[0] &
~(SCA3000_REG_INT_MASK_RING_THREE_QUARTER |
SCA3000_REG_INT_MASK_RING_HALF |
SCA3000_REG_INT_MASK_ALL_INTS)));
-error_ret:
- mutex_unlock(&st->lock);
- return ret;
}
static void sca3000_remove(struct spi_device *spi)
--
2.53.0