Re: [PATCH 25/29] iio: adc: max11410: Factor out writing of sampling frequency to simplify errro paths.

[Nuno Sá <noname.nuno@xxxxxxxxx>]

On Mon, 2025-02-17 at 14:16 +0000, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> 
> Introduce __max11410_write_samp_freq() helper and use guard() to avoid
> need for manual unlock of the mutex. This allows direct returns and
> simplifies the resulting error handling.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---

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

>  drivers/iio/adc/max11410.c | 51 ++++++++++++++++++++------------------
>  1 file changed, 27 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/iio/adc/max11410.c b/drivers/iio/adc/max11410.c
> index 76abafd47404..6e06c62715a8 100644
> --- a/drivers/iio/adc/max11410.c
> +++ b/drivers/iio/adc/max11410.c
> @@ -507,12 +507,37 @@ static int max11410_read_raw(struct iio_dev *indio_dev,
>  	return -EINVAL;
>  }
>  
> +static int __max11410_write_samp_freq(struct max11410_state *st,
> +				      int val, int val2)
> +{
> +	int ret, i, reg_val, filter;
> +
> +	guard(mutex)(&st->lock);
> +
> +	ret = regmap_read(st->regmap, MAX11410_REG_FILTER, &reg_val);
> +	if (ret)
> +		return ret;
> +
> +	filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
> +
> +	for (i = 0; i < max11410_sampling_len[filter]; ++i) {
> +		if (val == max11410_sampling_rates[filter][i][0] &&
> +		    val2 == max11410_sampling_rates[filter][i][1])
> +			break;
> +	}
> +	if (i == max11410_sampling_len[filter])
> +		return -EINVAL;
> +
> +	return regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
> +				 MAX11410_FILTER_RATE_MASK, i);
> +}
> +
>  static int max11410_write_raw(struct iio_dev *indio_dev,
>  			      struct iio_chan_spec const *chan,
>  			      int val, int val2, long mask)
>  {
>  	struct max11410_state *st = iio_priv(indio_dev);
> -	int i, ret, reg_val, filter, gain;
> +	int ret, gain;
>  	u32 *scale_avail;
>  
>  	switch (mask) {
> @@ -544,29 +569,7 @@ static int max11410_write_raw(struct iio_dev *indio_dev,
>  		if (ret)
>  			return ret;
>  
> -		mutex_lock(&st->lock);
> -
> -		ret = regmap_read(st->regmap, MAX11410_REG_FILTER, &reg_val);
> -		if (ret)
> -			goto out;
> -
> -		filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
> -
> -		for (i = 0; i < max11410_sampling_len[filter]; ++i) {
> -			if (val == max11410_sampling_rates[filter][i][0] &&
> -			    val2 == max11410_sampling_rates[filter][i][1])
> -				break;
> -		}
> -		if (i == max11410_sampling_len[filter]) {
> -			ret = -EINVAL;
> -			goto out;
> -		}
> -
> -		ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
> -					MAX11410_FILTER_RATE_MASK, i);
> -
> -out:
> -		mutex_unlock(&st->lock);
> +		ret = __max11410_write_samp_freq(st, val, val2);
>  		iio_device_release_direct_mode(indio_dev);
>  
>  		return ret;