[PATCH 04/15] iio: adc: imx7d_adc: do not use internal iio_dev lock

Nuno Sá
2022-09-20T11:30:14Z

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/imx7d_adc.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/imx7d_adc.c b/drivers/iio/adc/imx7d_adc.c
index 86caff1d006b..fa19f5e09079 100644
--- a/drivers/iio/adc/imx7d_adc.c
+++ b/drivers/iio/adc/imx7d_adc.c
@@ -13,6 +13,7 @@
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>

@@ -108,7 +109,8 @@ struct imx7d_adc {
struct device *dev;
void __iomem *regs;
struct clk *clk;
-
+ /* lock to protect against multiple access to the device */
+ struct mutex lock;
u32 vref_uv;
u32 value;
u32 channel;
@@ -293,7 +295,7 @@ static int imx7d_adc_read_raw(struct iio_dev *indio_dev,

switch (mask) {
case IIO_CHAN_INFO_RAW:
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&info->lock);
reinit_completion(&info->completion);

channel = chan->channel & 0x03;
@@ -303,16 +305,16 @@ static int imx7d_adc_read_raw(struct iio_dev *indio_dev,
ret = wait_for_completion_interruptible_timeout
(&info->completion, IMX7D_ADC_TIMEOUT);
if (ret == 0) {
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&info->lock);
return -ETIMEDOUT;
}
if (ret < 0) {
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&info->lock);
return ret;
}

*val = info->value;
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&info->lock);
return IIO_VAL_INT;

case IIO_CHAN_INFO_SCALE:
@@ -487,6 +489,7 @@ static int imx7d_adc_probe(struct platform_device *pdev)

info = iio_priv(indio_dev);
info->dev = dev;
+ mutex_init(&info->lock);

info->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(info->regs))
--
2.37.3