[PATCH 05/15] iio: adc: lpc32xx_adc: do not use internal iio_dev lock

Nuno Sá
2022-09-20T11:30:45Z

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@analog.com>
---
drivers/iio/adc/lpc32xx_adc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c
index b56ce15255cf..4136cf536d58 100644
--- a/drivers/iio/adc/lpc32xx_adc.c
+++ b/drivers/iio/adc/lpc32xx_adc.c
@@ -15,6 +15,7 @@
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

@@ -49,6 +50,8 @@ struct lpc32xx_adc_state {
struct clk *clk;
struct completion completion;
struct regulator *vref;
+ /* lock to protect against multiple access to the device */
+ struct mutex lock;

u32 value;
};
@@ -64,10 +67,10 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev,

switch (mask) {
case IIO_CHAN_INFO_RAW:
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
ret = clk_prepare_enable(st->clk);
if (ret) {
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return ret;
}
/* Measurement setup */
@@ -80,7 +83,7 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev,
wait_for_completion(&st->completion); /* set by ISR */
clk_disable_unprepare(st->clk);
*val = st->value;
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);

return IIO_VAL_INT;

@@ -158,6 +161,7 @@ static int lpc32xx_adc_probe(struct platform_device *pdev)
return -ENOMEM;

st = iio_priv(iodev);
+ mutex_init(&st->lock);

st->adc_base = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
--
2.37.3