[PATCH 09/15] iio: adc: sc27xx_adc: do not use internal iio_dev lock

[Nuno Sá]

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

Signed-off-by: Nuno Sá <nuno.sa at analog.com>
---
 drivers/iio/adc/sc27xx_adc.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c
index f8421cbba8fa..1cdb4e83aaf3 100644
--- a/drivers/iio/adc/sc27xx_adc.c
+++ b/drivers/iio/adc/sc27xx_adc.c
@@ -4,6 +4,7 @@
 #include <linux/hwspinlock.h>
 #include <linux/iio/iio.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/nvmem-consumer.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
@@ -83,6 +84,8 @@ struct sc27xx_adc_data {
 	struct device *dev;
 	struct regulator *volref;
 	struct regmap *regmap;
+	/* lock to protect against multiple access to the device */
+	struct mutex lock;
 	/*
 	 * One hardware spinlock to synchronize between the multiple
 	 * subsystems which will access the unique ADC controller.
@@ -664,9 +667,9 @@ static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		mutex_lock(&indio_dev->mlock);
+		mutex_lock(&data->lock);
 		ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
-		mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&data->lock);
 
 		if (ret)
 			return ret;
@@ -675,10 +678,10 @@ static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_PROCESSED:
-		mutex_lock(&indio_dev->mlock);
+		mutex_lock(&data->lock);
 		ret = sc27xx_adc_read_processed(data, chan->channel, scale,
 						&tmp);
-		mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&data->lock);
 
 		if (ret)
 			return ret;
@@ -876,6 +879,7 @@ static int sc27xx_adc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	sc27xx_data = iio_priv(indio_dev);
+	mutex_init(&sc27xx_data->lock);
 
 	sc27xx_data->regmap = dev_get_regmap(dev->parent, NULL);
 	if (!sc27xx_data->regmap) {
-- 
2.37.3