[PATCH v2 05/16] iio: adc: ltc2947-core: do not use internal iio_dev lock

Nuno Sá
2022-10-04T13:51:14Z

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>
---
drivers/iio/adc/ltc2497-core.c | 7 +++++--
drivers/iio/adc/ltc2497.h | 2 ++
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c
index f52d37af4d1f..996f6cbbed3c 100644
--- a/drivers/iio/adc/ltc2497-core.c
+++ b/drivers/iio/adc/ltc2497-core.c
@@ -10,6 +10,7 @@
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/regulator/consumer.h>

#include "ltc2497.h"
@@ -81,9 +82,9 @@ static int ltc2497core_read_raw(struct iio_dev *indio_dev,

switch (mask) {
case IIO_CHAN_INFO_RAW:
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&ddata->lock);
ret = ltc2497core_read(ddata, chan->address, val);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&ddata->lock);
if (ret < 0)
return ret;

@@ -214,6 +215,8 @@ int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
ddata->time_prev = ktime_get();

+ mutex_init(&ddata->lock);
+
ret = iio_device_register(indio_dev);
if (ret < 0)
goto err_array_unregister;
diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
index e023de0d88c4..781519b52475 100644
--- a/drivers/iio/adc/ltc2497.h
+++ b/drivers/iio/adc/ltc2497.h
@@ -12,6 +12,8 @@ struct ltc2497_chip_info {
struct ltc2497core_driverdata {
struct regulator *ref;
ktime_t time_prev;
+ /* lock to protect against multiple access to the device */
+ struct mutex lock;
const struct ltc2497_chip_info *chip_info;
u8 addr_prev;
int (*result_and_measure)(struct ltc2497core_driverdata *ddata,
--
2.37.3