Commit 8f347c56 authored by Nuno Sá's avatar Nuno Sá Committed by Jonathan Cameron
Browse files

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: default avatarNuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20221004134909.1692021-2-nuno.sa@analog.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 3a258747

drivers/iio/adc/ad799x.c

+14 −6
Original line number Diff line number Diff line
@@ -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;