[PATCH v2 07/16] iio: adc: rockchip_saradc: do not use internal iio_dev lock

Nuno Sá
2022-10-04T13:51:55Z

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/rockchip_saradc.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
index b87ea7148b58..79448c5ffc2a 100644
--- a/drivers/iio/adc/rockchip_saradc.c
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -5,6 +5,7 @@
*/

#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
@@ -49,6 +50,8 @@ struct rockchip_saradc {
struct clk *clk;
struct completion completion;
struct regulator *vref;
+ /* lock to protect against multiple access to the device */
+ struct mutex lock;
int uv_vref;
struct reset_control *reset;
const struct rockchip_saradc_data *data;
@@ -94,17 +97,17 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,

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

ret = rockchip_saradc_conversion(info, chan);
if (ret) {
rockchip_saradc_power_down(info);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&info->lock);
return ret;
}

*val = info->last_val;
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&info->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = info->uv_vref / 1000;
@@ -270,7 +273,7 @@ static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)
int ret;
int i, j = 0;

- mutex_lock(&i_dev->mlock);
+ mutex_lock(&info->lock);

for_each_set_bit(i, i_dev->active_scan_mask, i_dev->masklength) {
const struct iio_chan_spec *chan = &i_dev->channels[i];
@@ -287,7 +290,7 @@ static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p)

iio_push_to_buffers_with_timestamp(i_dev, &data, iio_get_time_ns(i_dev));
out:
- mutex_unlock(&i_dev->mlock);
+ mutex_unlock(&info->lock);

iio_trigger_notify_done(i_dev->trig);

@@ -478,6 +481,8 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
if (ret)
return ret;

+ mutex_init(&info->lock);
+
return devm_iio_device_register(&pdev->dev, indio_dev);
}

--
2.37.3