iio: adc: axp288_adc: 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/20221004134909.1692021-3-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/axp288_adc.c b/drivers/iio/adc/axp288_adc.c
index 580361bd98492a07654aa86b19eae18d3cfbf5ba..49fff1cabd0dc56e6d4d71d3cbb8fb7cb34c9e5b 100644 (file)
--- a/drivers/iio/adc/axp288_adc.c
+++ b/drivers/iio/adc/axp288_adc.c
@@ -9,6 +9,7 @@
 
 #include <linux/dmi.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/regmap.h>
@@ -50,6 +51,8 @@ enum axp288_adc_id {
 struct axp288_adc_info {
        int irq;
        struct regmap *regmap;
+       /* lock to protect against multiple access to the device */
+       struct mutex lock;
        bool ts_enabled;
 };
 
@@ -161,7 +164,7 @@ static int axp288_adc_read_raw(struct iio_dev *indio_dev,
        int ret;
        struct axp288_adc_info *info = iio_priv(indio_dev);
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&info->lock);
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (axp288_adc_set_ts(info, AXP288_ADC_TS_CURRENT_ON_ONDEMAND,
@@ -178,7 +181,7 @@ static int axp288_adc_read_raw(struct iio_dev *indio_dev,
        default:
                ret = -EINVAL;
        }
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&info->lock);
 
        return ret;
 }
@@ -289,6 +292,8 @@ static int axp288_adc_probe(struct platform_device *pdev)
        if (ret < 0)
                return ret;
 
+       mutex_init(&info->lock);
+
        return devm_iio_device_register(&pdev->dev, indio_dev);
 }