iio: gyro: itg3200_core: do not use internal iio_dev lock

The iio_device lock is only meant for internal use. Hence define a
device local lock to protect against concurrent accesses.

While at it, properly include "mutex.h" for mutex related APIs.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20221004134909.1692021-13-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/gyro/itg3200_core.c b/drivers/iio/gyro/itg3200_core.c
index 4215015..74ca224 100644 (file)
--- a/drivers/iio/gyro/itg3200_core.c
+++ b/drivers/iio/gyro/itg3200_core.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/stat.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/delay.h>
 
 #include <linux/iio/iio.h>
@@ -131,6 +132,7 @@ static int itg3200_write_raw(struct iio_dev *indio_dev,
                             int val2,
                             long mask)
 {
+       struct itg3200 *st = iio_priv(indio_dev);
        int ret;
        u8 t;
 
@@ -139,11 +141,11 @@ static int itg3200_write_raw(struct iio_dev *indio_dev,
                if (val == 0 || val2 != 0)
                        return -EINVAL;
 
-               mutex_lock(&indio_dev->mlock);
+               mutex_lock(&st->lock);
 
                ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
                if (ret) {
-                       mutex_unlock(&indio_dev->mlock);
+                       mutex_unlock(&st->lock);
                        return ret;
                }
                t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
@@ -152,7 +154,7 @@ static int itg3200_write_raw(struct iio_dev *indio_dev,
                                          ITG3200_REG_SAMPLE_RATE_DIV,
                                          t);
 
-               mutex_unlock(&indio_dev->mlock);
+               mutex_unlock(&st->lock);
                return ret;
 
        default:
@@ -336,6 +338,8 @@ static int itg3200_probe(struct i2c_client *client,
        if (ret)
                goto error_remove_trigger;
 
+       mutex_init(&st->lock);
+
        ret = iio_device_register(indio_dev);
        if (ret)
                goto error_remove_trigger;

diff --git a/include/linux/iio/gyro/itg3200.h b/include/linux/iio/gyro/itg3200.h
index a602fe7..74b6d1c 100644 (file)
--- a/include/linux/iio/gyro/itg3200.h
+++ b/include/linux/iio/gyro/itg3200.h
@@ -102,6 +102,8 @@ struct itg3200 {
        struct i2c_client       *i2c;
        struct iio_trigger      *trig;
        struct iio_mount_matrix orientation;
+       /* lock to protect against multiple access to the device */
+       struct mutex            lock;
 };
 
 enum ITG3200_SCAN_INDEX {