On Thu, 20 Feb 2025 10:42:29 +0000
Lothar Rubusch <l.rubusch@xxxxxxxxx> 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. The patch is in
> preparation for activity/inactivity handling. During adjustment of
> bw registers, measuring is disabled and afterwards enabled again.
>
> Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx>
Hi Lothar, a few minor things inline.
> +static int adxl345_find_odr(struct adxl345_state *st, int val,
> + int val2, enum adxl345_odr *odr)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(adxl345_odr_tbl); i++)
> + if (val == adxl345_odr_tbl[i][0] &&
> + val2 == adxl345_odr_tbl[i][1])
> + break;
> +
> + if (i == ARRAY_SIZE(adxl345_odr_tbl))
> + return -EINVAL;
> +
> + *odr = i;
> +
> + return 0;
Unless there will be more to do here later it would be fine to
move this setting *odr = i and return into the loop condition.
Then you can return -EINVAL directly if the loop finishes.
i.e.
for (i = 0; i < ARRAY_SIZE(adxl345_odr_tbl); i++) {
if (val == adxl345_odr_tbl[i][0] &&
val2 == adxl345_odr_tbl[i][1]) {
*odr = i;
return 0;
}
}
return -EINVAL;
This is a very common pattern when there isn't much
to do on a match.
> +}
> +
> +static int adxl345_set_odr(struct adxl345_state *st, enum adxl345_odr odr)
> +{
> + int ret;
> +
> + ret = regmap_update_bits(st->regmap, ADXL345_REG_BW_RATE,
> + ADXL345_BW_RATE_MSK,
> + FIELD_PREP(ADXL345_BW_RATE_MSK, odr));
> + if (ret)
> + return ret;
I guess this makes sense in later patches, but if it doesn't get more
complex
return regmap()
> +
> + return 0;
> +}
> +
> +static int adxl345_read_avail(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + const int **vals, int *type,
> + int *length, long mask)
> +{
> + switch (mask) {
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + *vals = (int *)adxl345_odr_tbl;
> + *type = IIO_VAL_INT_PLUS_MICRO;
> + *length = ARRAY_SIZE(adxl345_odr_tbl) * 2;
> + return IIO_AVAIL_LIST;
> + }
> +
> + return -EINVAL;
> +}
> +
> static int adxl345_read_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int *val, int *val2, long mask)
> {
> struct adxl345_state *st = iio_priv(indio_dev);
> __le16 accel;
> - long long samp_freq_nhz;
> unsigned int regval;
> + enum adxl345_odr odr;
> int ret;
>
> switch (mask) {
> @@ -455,14 +542,12 @@ static int adxl345_read_raw(struct iio_dev *indio_dev,
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SAMP_FREQ:
> ret = regmap_read(st->regmap, ADXL345_REG_BW_RATE, ®val);
> - if (ret < 0)
> + if (ret)
> return ret;
Change is reasonable but unrelated to this patch that I can see. Should
really be a separate patch cleaning these up for all regmap calls.
I have no idea if there are others.
> -
> - samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ <<
> - (regval & ADXL345_BW_RATE);
> - *val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2);
> -
> - return IIO_VAL_INT_PLUS_NANO;
> + odr = FIELD_GET(ADXL345_BW_RATE_MSK, regval);
> + *val = adxl345_odr_tbl[odr][0];
> + *val2 = adxl345_odr_tbl[odr][1];
> + return IIO_VAL_INT_PLUS_MICRO;
> }
>
> return -EINVAL;
> @@ -473,7 +558,12 @@ 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);
> + if (ret)
> + return ret;
>
> switch (mask) {
> case IIO_CHAN_INFO_CALIBBIAS:
> @@ -481,20 +571,24 @@ 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);
I'd do local error handling here...
> + break;
> case IIO_CHAN_INFO_SAMP_FREQ:
> - n = div_s64(val * NANOHZ_PER_HZ + val2,
> - ADXL345_BASE_RATE_NANO_HZ);
> -
> - return regmap_update_bits(st->regmap, ADXL345_REG_BW_RATE,
> - ADXL345_BW_RATE,
> - clamp_val(ilog2(n), 0,
> - ADXL345_BW_RATE));
> + ret = adxl345_find_odr(st, val, val2, &odr);
> + if (ret)
> + return ret;
> + ret = adxl345_set_odr(st, odr);
and here just to be consistent with the case above here
if (ret)
return ret;
> + break;
> + default:
> + return -EINVAL;
> }
>
> - return -EINVAL;
> + if (ret)
This this one is never hit.
> + return ret;
> +
> + return adxl345_set_measure_en(st, true);
> }
>
> static int adxl345_read_event_config(struct iio_dev *indio_dev,
> @@ -747,7 +841,7 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
> case IIO_CHAN_INFO_CALIBBIAS:
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SAMP_FREQ:
> - return IIO_VAL_INT_PLUS_NANO;
> + return IIO_VAL_INT_PLUS_MICRO;
> default:
> return -EINVAL;
> }
> @@ -760,19 +854,6 @@ static void adxl345_powerdown(void *ptr)
> adxl345_set_measure_en(st, false);
> }
>
> -static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
> -"0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
> -);
