[PATCH v2 08/16] iio: adc: sc27xx_adc: do not use internal iio_dev lock

Nuno Sá
2022-10-04T13:49:52Z

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/sc27xx_adc.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/sc27xx_adc.c b/drivers/iio/adc/sc27xx_adc.c
index f8421cbba8fa..ff1fc329bb9b 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;
@@ -934,6 +937,9 @@ static int sc27xx_adc_probe(struct platform_device *pdev)
indio_dev->info = &sc27xx_info;
indio_dev->channels = sc27xx_channels;
indio_dev->num_channels = ARRAY_SIZE(sc27xx_channels);
+
+ mutex_init(&sc27xx_data->lock);
+
ret = devm_iio_device_register(dev, indio_dev);
if (ret)
dev_err(dev, "could not register iio (ADC)");
--
2.37.3