Re: [PATCH v5 06/11] iio: accel: adxl345: extend sample frequency adjustments

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 18 Mar 2025 23:08:38 +0000
Lothar Rubusch <l.rubusch@gmail.com> wrote:

> Introduce enums and functions to work with the sample frequency
> adjustments. Let the sample frequency adjust via IIO and configure
> a reasonable default.
> 
> Replace the old static sample frequency handling. During adjustment of
> bw registers, measuring is disabled and afterwards enabled again.
> 
> Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
One minor thing inline.


>  	return -EINVAL;
> @@ -504,7 +581,12 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
>  			     int val, int val2, long mask)
>  {
>  	struct adxl345_state *st = iio_priv(indio_dev);
> -	s64 n;
> +	enum adxl345_odr odr;
> +	int ret;
> +
> +	ret = adxl345_set_measure_en(st, false);

Why is this necessary but wasn't before?
If it should always have been done for existing calibbias etc,
perhaps a separate precursor patch is appropriate?


> +	if (ret)
> +		return ret;
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_CALIBBIAS:
> @@ -512,20 +594,26 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
>  		 * 8-bit resolution at +/- 2g, that is 4x accel data scale
>  		 * factor
>  		 */
> -		return regmap_write(st->regmap,
> -				    ADXL345_REG_OFS_AXIS(chan->address),
> -				    val / 4);
> +		ret = regmap_write(st->regmap,
> +				   ADXL345_REG_OFS_AXIS(chan->address),
> +				   val / 4);
> +		if (ret)
> +			return ret;
> +		break;
>  	case IIO_CHAN_INFO_SAMP_FREQ:
> -		n = div_s64(val * NANOHZ_PER_HZ + val2,
> -			    ADXL345_BASE_RATE_NANO_HZ);
> +		ret = adxl345_find_odr(st, val, val2, &odr);
> +		if (ret)
> +			return ret;
>  
> -		return regmap_update_bits(st->regmap, ADXL345_REG_BW_RATE,
> -					  ADXL345_BW_RATE,
> -					  clamp_val(ilog2(n), 0,
> -						    ADXL345_BW_RATE));
> +		ret = adxl345_set_odr(st, odr);
> +		if (ret)
> +			return ret;
> +		break;
> +	default:
> +		return -EINVAL;
>  	}
>  
> -	return -EINVAL;
> +	return adxl345_set_measure_en(st, true);
>  }