[PATCH 07/15] iio: adc: meson_saradc: do not use internal iio_dev lock

Nuno Sá
2022-09-20T11:31:42Z

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/meson_saradc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 1a68b099d323..45d6e3d4b0ce 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -12,6 +12,7 @@
#include <linux/io.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/nvmem-consumer.h>
#include <linux/interrupt.h>
#include <linux/of.h>
@@ -276,6 +277,8 @@ struct meson_sar_adc_priv {
struct clk *adc_div_clk;
struct clk_divider clk_div;
struct completion done;
+ /* lock to protect against multiple access to the device */
+ struct mutex lock;
int calibbias;
int calibscale;
struct regmap *tsc_regmap;
@@ -486,7 +489,7 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev)
struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
int val, ret;

- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&priv->lock);

if (priv->param->has_bl30_integration) {
/* prevent BL30 from using the SAR ADC while we are using it */
@@ -504,7 +507,7 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev)
!(val & MESON_SAR_ADC_DELAY_BL30_BUSY),
1, 10000);
if (ret) {
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&priv->lock);
return ret;
}
}
@@ -521,7 +524,7 @@ static void meson_sar_adc_unlock(struct iio_dev *indio_dev)
regmap_update_bits(priv->regmap, MESON_SAR_ADC_DELAY,
MESON_SAR_ADC_DELAY_KERNEL_BUSY, 0);

- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&priv->lock);
}

static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev)
@@ -1174,6 +1177,7 @@ static int meson_sar_adc_probe(struct platform_device *pdev)

priv = iio_priv(indio_dev);
init_completion(&priv->done);
+ mutex_init(&priv->lock);

match_data = of_device_get_match_data(dev);
if (!match_data)
--
2.37.3