[PATCH v2 05/16] iio: adc: ltc2947-core: do not use internal iio_dev lock

[Jonathan Cameron]

On Tue, 4 Oct 2022 15:48:58 +0200
Nuno Sá <nuno.sa at analog.com> wrote:

> 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 at analog.com>
Applied

> ---
>  drivers/iio/adc/ltc2497-core.c | 7 +++++--
>  drivers/iio/adc/ltc2497.h      | 2 ++
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c
> index f52d37af4d1f..996f6cbbed3c 100644
> --- a/drivers/iio/adc/ltc2497-core.c
> +++ b/drivers/iio/adc/ltc2497-core.c
> @@ -10,6 +10,7 @@
>  #include <linux/iio/iio.h>
>  #include <linux/iio/driver.h>
>  #include <linux/module.h>
> +#include <linux/mutex.h>
>  #include <linux/regulator/consumer.h>
>  
>  #include "ltc2497.h"
> @@ -81,9 +82,9 @@ static int ltc2497core_read_raw(struct iio_dev *indio_dev,
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
> -		mutex_lock(&indio_dev->mlock);
> +		mutex_lock(&ddata->lock);
>  		ret = ltc2497core_read(ddata, chan->address, val);
> -		mutex_unlock(&indio_dev->mlock);
> +		mutex_unlock(&ddata->lock);
>  		if (ret < 0)
>  			return ret;
>  
> @@ -214,6 +215,8 @@ int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
>  	ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
>  	ddata->time_prev = ktime_get();
>  
> +	mutex_init(&ddata->lock);
> +
>  	ret = iio_device_register(indio_dev);
>  	if (ret < 0)
>  		goto err_array_unregister;
> diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
> index e023de0d88c4..781519b52475 100644
> --- a/drivers/iio/adc/ltc2497.h
> +++ b/drivers/iio/adc/ltc2497.h
> @@ -12,6 +12,8 @@ struct ltc2497_chip_info {
>  struct ltc2497core_driverdata {
>  	struct regulator *ref;
>  	ktime_t	time_prev;
> +	/* lock to protect against multiple access to the device */
> +	struct mutex lock;
>  	const struct ltc2497_chip_info	*chip_info;
>  	u8 addr_prev;
>  	int (*result_and_measure)(struct ltc2497core_driverdata *ddata,