Re: [PATCH v3 8/9] iio: accel: bma400: Add debugfs register access support

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 12 Apr 2022 02:01:32 +0530
Jagath Jog J <jagathjog1996@gmail.com> wrote:

> Add support to read/write byte from/to bma400 device from the userspace
> using debugfs interface.
> 
> Signed-off-by: Jagath Jog J <jagathjog1996@gmail.com>
> ---
>  drivers/iio/accel/bma400_core.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c
> index 69d2caa4ed18..b6c79cfabaa4 100644
> --- a/drivers/iio/accel/bma400_core.c
> +++ b/drivers/iio/accel/bma400_core.c
> @@ -1028,6 +1028,23 @@ static int bma400_write_event_config(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static int bma400_debugfs_reg_access(struct iio_dev *indio_dev,
> +				     unsigned int reg,
> +				     unsigned int writeval,
> +				     unsigned int *readval)
> +{
> +	struct bma400_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);

Guess what? :)  Can't see what purpose locking this has.

> +	if (readval)
> +		ret = regmap_read(data->regmap, reg, readval);
> +	else
> +		ret = regmap_write(data->regmap, reg, writeval);
> +	mutex_unlock(&data->mutex);
> +	return ret;
> +}
> +
>  static int bma400_data_rdy_trigger_set_state(struct iio_trigger *trig,
>  					     bool state)
>  {
> @@ -1058,6 +1075,7 @@ static const struct iio_info bma400_info = {
>  	.write_raw_get_fmt = bma400_write_raw_get_fmt,
>  	.read_event_config = bma400_read_event_config,
>  	.write_event_config = bma400_write_event_config,
> +	.debugfs_reg_access = bma400_debugfs_reg_access,
>  };
>  
>  static const struct iio_trigger_ops bma400_trigger_ops = {