On Sun, 4 Sept 2022 at 17:19, Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Sun, 4 Sep 2022 00:24:02 +0200
> cmo@xxxxxxxxxxx wrote:
>
> > From: Crt Mori <cmo@xxxxxxxxxxx>
> >
> > Allow users to read sensor sampling frequency to better plan the
> > application measurement requests.
>
> I didn't read this closely enough. Why is the frequency read only?
> We'd not normally have an available attribute in that case, because
> the values aren't available if we have no way to set the value.
>
It is writable, but so far I did not want to include the change part,
because it is writing to EEPROM and that means sensor slowly gets
killed as memory has limited number of write cycles.
> Jonathan
>
> >
> > Signed-off-by: Crt Mori <cmo@xxxxxxxxxxx>
> > ---
> > drivers/iio/temperature/mlx90632.c | 44 ++++++++++++++++++++++++++++++
> > 1 file changed, 44 insertions(+)
> >
> > diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
> > index 9acd819c76a6..37edd324d6a1 100644
> > --- a/drivers/iio/temperature/mlx90632.c
> > +++ b/drivers/iio/temperature/mlx90632.c
> > @@ -80,6 +80,9 @@
> > #define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous */
> >
> > #define MLX90632_EE_RR(ee_val) (ee_val & GENMASK(10, 8)) /* Only Refresh Rate bits */
> > +#define MLX90632_REFRESH_RATE(ee_val) (MLX90632_EE_RR(ee_val) >> 8)
> > + /* Extract Refresh Rate from ee register */
> > +#define MLX90632_REFRESH_RATE_STATUS(refresh_rate) (refresh_rate << 8)
> >
> > /* Measurement types */
> > #define MLX90632_MTYP_MEDICAL 0
> > @@ -908,6 +911,24 @@ static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
> > return ret;
> > }
> >
> > +static int mlx90632_get_refresh_rate(struct mlx90632_data *data,
> > + int *refresh_rate)
> > +{
> > + unsigned int meas1;
> > + int ret;
> > +
> > + ret = regmap_read(data->regmap, MLX90632_EE_MEDICAL_MEAS1, &meas1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + *refresh_rate = MLX90632_REFRESH_RATE(meas1);
> > +
> > + return ret;
> > +}
> > +
> > +static const int mlx90632_freqs[][2] = { {0, 500000}, {1, 0}, {2, 0}, {4, 0},
> > + {8, 0}, {16, 0}, {32, 0}, {64, 0} };
> > +
> > static int mlx90632_pm_interraction_wakeup(struct mlx90632_data *data)
> > {
> > unsigned long now;
> > @@ -978,6 +999,15 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
> > *val = data->object_ambient_temperature;
> > ret = IIO_VAL_INT;
> > break;
> > + case IIO_CHAN_INFO_SAMP_FREQ:
> > + ret = mlx90632_get_refresh_rate(data, &cr);
> > + if (ret < 0)
> > + goto mlx90632_read_raw_pm;
> > +
> > + *val = mlx90632_freqs[cr][0];
> > + *val2 = mlx90632_freqs[cr][1];
> > + ret = IIO_VAL_INT_PLUS_MICRO;
> > + break;
> > default:
> > ret = -EINVAL;
> > break;
> > @@ -1012,12 +1042,24 @@ static int mlx90632_write_raw(struct iio_dev *indio_dev,
> > }
> > }
> >
> > +static IIO_CONST_ATTR(sampling_frequency_available, "0.5 1 2 4 8 16 32 64");
> > +
> > +static struct attribute *mlx90632_attributes[] = {
> > + &iio_const_attr_sampling_frequency_available.dev_attr.attr,
> > + NULL
> > +};
> > +
> > +static const struct attribute_group mlx90632_attribute_group = {
> > + .attrs = mlx90632_attributes,
> > +};
> > +
> > static const struct iio_chan_spec mlx90632_channels[] = {
> > {
> > .type = IIO_TEMP,
> > .modified = 1,
> > .channel2 = IIO_MOD_TEMP_AMBIENT,
> > .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> > + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> > },
> > {
> > .type = IIO_TEMP,
> > @@ -1025,12 +1067,14 @@ static const struct iio_chan_spec mlx90632_channels[] = {
> > .channel2 = IIO_MOD_TEMP_OBJECT,
> > .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> > BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | BIT(IIO_CHAN_INFO_CALIBAMBIENT),
> > + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> > },
> > };
> >
> > static const struct iio_info mlx90632_info = {
> > .read_raw = mlx90632_read_raw,
> > .write_raw = mlx90632_write_raw,
> > + .attrs = &mlx90632_attribute_group,
> > };
> >
> > static int mlx90632_sleep(struct mlx90632_data *data)
>
