iio: adc: ltc2947-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/20221004134909.1692021-6-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c
index f52d37a..996f6cb 100644 (file)
--- 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 e023de0..781519b 100644 (file)
--- 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,