Re: [PATCH] iio: adc: adc7266: Use iio_device_claim_direct_scoped()

[Jonathan Cameron <jic23@kernel.org>]

On Wed,  8 May 2024 12:54:35 -0300
Fernando Yang <hagisf@usp.br> wrote:

> Switching to the _scoped() version can make the error
> handling more natural instead of delayed until direct
> mode was released.
> 
> Co-developed-by: Eduardo Figueredo <eduardofp@usp.br>
> Signed-off-by: Eduardo Figueredo <eduardofp@usp.br>
> Signed-off-by: Fernando Yang <hagisf@usp.br>
> ---
>  drivers/iio/adc/ad7266.c | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7266.c b/drivers/iio/adc/ad7266.c
> index 8b03d4469..3fc34a3a8 100644
> --- a/drivers/iio/adc/ad7266.c
> +++ b/drivers/iio/adc/ad7266.c
> @@ -63,12 +63,14 @@ static int ad7266_powerdown(struct ad7266_state *st)
>  static int ad7266_preenable(struct iio_dev *indio_dev)
>  {
>  	struct ad7266_state *st = iio_priv(indio_dev);
> +
>  	return ad7266_wakeup(st);
>  }
>  
>  static int ad7266_postdisable(struct iio_dev *indio_dev)
>  {
>  	struct ad7266_state *st = iio_priv(indio_dev);
> +
>  	return ad7266_powerdown(st);
>  }
>  
> @@ -151,15 +153,16 @@ static int ad7266_read_raw(struct iio_dev *indio_dev,
>  
>  	switch (m) {
>  	case IIO_CHAN_INFO_RAW:
> -		iio_device_claim_direct_scoped(return -EBUSY, indio_dev)
This isn't the existing code. I'm guessing you have another commit ahead
of this one on your branch?

> +		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
>  			ret = ad7266_read_single(st, val, chan->address);
Not checking ret here is a bug in the existing code.  Please fix that as
a precursor patch before making the _scoped change.

The check will have to be immediately after iio_device_release_direct_mode()
in the existing code.

>  
> -		*val = (*val >> 2) & 0xfff;
> -		if (chan->scan_type.sign == 's')
> -			*val = sign_extend32(*val,
> -						 chan->scan_type.realbits - 1);
> +			*val = (*val >> 2) & 0xfff;
> +			if (chan->scan_type.sign == 's')
> +				*val = sign_extend32(*val,
> +							 chan->scan_type.realbits - 1);
>  
> -		return IIO_VAL_INT;
> +			return IIO_VAL_INT;
> +		}
>  		unreachable();
>  	case IIO_CHAN_INFO_SCALE:
>  		scale_mv = st->vref_mv;