Re: [PATCH 17/29] iio: adc: ad7793: Factor out core of ad7793_write_raw() to simplify error handling

["Nuno Sá" <noname.nuno@gmail.com>]

On Mon, 2025-02-17 at 14:16 +0000, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> Factor out everything under the direct mode claim allowing direct returns
> in error paths.  Switch sense of matching in the loop and use a continue
> to reduce code indent and improve readability.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/iio/adc/ad7793.c | 79 +++++++++++++++++++++-------------------
>  1 file changed, 42 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
> index 1b50d9643a63..861a3e44e5ad 100644
> --- a/drivers/iio/adc/ad7793.c
> +++ b/drivers/iio/adc/ad7793.c
> @@ -462,64 +462,69 @@ static int ad7793_read_raw(struct iio_dev *indio_dev,
>  	return -EINVAL;
>  }
>  
> -static int ad7793_write_raw(struct iio_dev *indio_dev,
> -			       struct iio_chan_spec const *chan,
> -			       int val,
> -			       int val2,
> -			       long mask)
> +static int __ad7793_write_raw(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan,
> +			      int val, int val2, long mask)
>  {
>  	struct ad7793_state *st = iio_priv(indio_dev);
> -	int ret, i;
> +	int i;
>  	unsigned int tmp;
>  
> -	ret = iio_device_claim_direct_mode(indio_dev);
> -	if (ret)
> -		return ret;
> -
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SCALE:
> -		ret = -EINVAL;
> -		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
> -			if (val2 == st->scale_avail[i][1]) {
> -				ret = 0;
> -				tmp = st->conf;
> -				st->conf &= ~AD7793_CONF_GAIN(-1);
> -				st->conf |= AD7793_CONF_GAIN(i);
> -
> -				if (tmp == st->conf)
> -					break;
> -
> -				ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
> -						sizeof(st->conf), st->conf);
> -				ad7793_calibrate_all(st);
> -				break;
> -			}
> -		break;
> -	case IIO_CHAN_INFO_SAMP_FREQ:
> -		if (!val) {
> -			ret = -EINVAL;
> -			break;
> +		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
> +			if (val2 != st->scale_avail[i][1])
> +				continue;
> +
> +			tmp = st->conf;
> +			st->conf &= ~AD7793_CONF_GAIN(-1);
> +			st->conf |= AD7793_CONF_GAIN(i);
> +
> +			if (tmp == st->conf)
> +				return 0;
> +
> +			ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
> +					sizeof(st->conf), st->conf);
> +			ad7793_calibrate_all(st);
> +
> +			return 0;
>  		}
> +		return -EINVAL;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		if (!val)
> +			return -EINVAL;
>  
>  		for (i = 0; i < 16; i++)
>  			if (val == st->chip_info->sample_freq_avail[i])
>  				break;
>  
> -		if (i == 16) {
> -			ret = -EINVAL;
> -			break;
> -		}
> +		if (i == 16)
> +			return -EINVAL;
>  
>  		st->mode &= ~AD7793_MODE_RATE(-1);
>  		st->mode |= AD7793_MODE_RATE(i);
>  		ad_sd_write_reg(&st->sd, AD7793_REG_MODE, sizeof(st->mode),
>  				st->mode);
> -		break;
> +		return 0;
>  	default:
> -		ret = -EINVAL;
> +		return -EINVAL;
>  	}
> +}
> +
> +static int ad7793_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val, int val2, long mask)
> +{
> +	int ret;
> +
> +	ret = iio_device_claim_direct_mode(indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = __ad7793_write_raw(indio_dev, chan, val, val2, mask);
>  
>  	iio_device_release_direct_mode(indio_dev);
> +
>  	return ret;
>  }
>