diff options
| author | Nuno Sá <nuno.sa@analog.com> | 2022-10-04 15:48:54 +0200 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2022-11-23 19:43:57 +0000 |
| commit | 8f347c565df4e8dd2c862a48a3056bfe59d315e9 (patch) | |
| tree | f3941011f26d4502acdaac206944417343c0c3e4 | |
| parent | 3a258747a01f1f21fd4c10a07499bde684f8ca2a (diff) | |
iio: adc: ad799x: do not use internal iio_dev lock
'mlock' was being grabbed when setting the device frequency. In order to
not introduce any functional change a new lock is added. With that in
mind, the lock also needs to be grabbed in the places where 'mlock' is
since it was also being used to protect st->config against the current
device state.
On the other places the lock was being used, we can just drop
it since we are only doing one i2c bus read/write which is already
safe.
While at it, properly include "mutex.h" for mutex related APIs.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20221004134909.1692021-2-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
| -rw-r--r-- | drivers/iio/adc/ad799x.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c index 6dbe9d5e08a2..4730d8d0f4c3 100644 --- a/drivers/iio/adc/ad799x.c +++ b/drivers/iio/adc/ad799x.c @@ -28,6 +28,7 @@ #include <linux/types.h> #include <linux/err.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/bitops.h> #include <linux/iio/iio.h> @@ -125,6 +126,8 @@ struct ad799x_state { const struct ad799x_chip_config *chip_config; struct regulator *reg; struct regulator *vref; + /* lock to protect against multiple access to the device */ + struct mutex lock; unsigned id; u16 config; @@ -290,7 +293,9 @@ static int ad799x_read_raw(struct iio_dev *indio_dev, ret = iio_device_claim_direct_mode(indio_dev); if (ret) return ret; + mutex_lock(&st->lock); ret = ad799x_scan_direct(st, chan->scan_index); + mutex_unlock(&st->lock); iio_device_release_direct_mode(indio_dev); if (ret < 0) @@ -351,7 +356,8 @@ static ssize_t ad799x_write_frequency(struct device *dev, if (ret) return ret; - mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); + ret = i2c_smbus_read_byte_data(st->client, AD7998_CYCLE_TMR_REG); if (ret < 0) goto error_ret_mutex; @@ -373,7 +379,7 @@ static ssize_t ad799x_write_frequency(struct device *dev, ret = len; error_ret_mutex: - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return ret; } @@ -407,6 +413,8 @@ static int ad799x_write_event_config(struct iio_dev *indio_dev, if (ret) return ret; + mutex_lock(&st->lock); + if (state) st->config |= BIT(chan->scan_index) << AD799X_CHANNEL_SHIFT; else @@ -418,6 +426,7 @@ static int ad799x_write_event_config(struct iio_dev *indio_dev, st->config &= ~AD7998_ALERT_EN; ret = ad799x_write_config(st, st->config); + mutex_unlock(&st->lock); iio_device_release_direct_mode(indio_dev); return ret; } @@ -454,11 +463,9 @@ static int ad799x_write_event_value(struct iio_dev *indio_dev, if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0)) return -EINVAL; - mutex_lock(&indio_dev->mlock); ret = i2c_smbus_write_word_swapped(st->client, ad799x_threshold_reg(chan, dir, info), val << chan->scan_type.shift); - mutex_unlock(&indio_dev->mlock); return ret; } @@ -473,10 +480,8 @@ static int ad799x_read_event_value(struct iio_dev *indio_dev, int ret; struct ad799x_state *st = iio_priv(indio_dev); - mutex_lock(&indio_dev->mlock); ret = i2c_smbus_read_word_swapped(st->client, ad799x_threshold_reg(chan, dir, info)); - mutex_unlock(&indio_dev->mlock); if (ret < 0) return ret; *val = (ret >> chan->scan_type.shift) & @@ -863,6 +868,9 @@ static int ad799x_probe(struct i2c_client *client, if (ret) goto error_cleanup_ring; } + + mutex_init(&st->lock); + ret = iio_device_register(indio_dev); if (ret) goto error_cleanup_ring; |