On Thu, 21 Sep 2023 09:43:59 -0500
David Lechner <dlechner@xxxxxxxxxxxx> wrote:
> This adds new phase_lock_range and phase_lock_range_available attributes
> to the ad2s1210 resolver driver. These attributes allow the user to set
> the phase lock range bit in the control register to modify the behavior
> of the resolver to digital converter.
>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
The guard() and scoped_guard() magic will work well in here.
Otherwise, I think as you raised in the cover letter, that the interface
needs some thought as far form obvious what a phase_lock is + nonstandard
ABI is best avoided if we can.
Jonathan
> ---
> drivers/staging/iio/resolver/ad2s1210.c | 58 +++++++++++++++++++++++++
> 1 file changed, 58 insertions(+)
>
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index 71f0913b7e2e..f5b8b290e860 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -259,6 +259,60 @@ static ssize_t excitation_frequency_store(struct device *dev,
> return ret;
> }
>
> +static ssize_t phase_lock_range_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
> + int ret;
> +
> + mutex_lock(&st->lock);
> + ret = regmap_test_bits(st->regmap, AD2S1210_REG_CONTROL,
> + AD2S1210_PHASE_LOCK_RANGE_44);
> + if (ret < 0)
> + goto error_ret;
> +
> + ret = sprintf(buf, "%d\n", ret ? 44 : 360);
> +
> +error_ret:
> + mutex_unlock(&st->lock);
> + return ret;
> +}
> +
> +static ssize_t phase_lock_range_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
> + u16 udata;
> + int ret;
> +
> + ret = kstrtou16(buf, 10, &udata);
> + if (ret < 0 || (udata != 44 && udata != 360))
> + return -EINVAL;
> +
> + mutex_lock(&st->lock);
> +
> + ret = regmap_update_bits(st->regmap, AD2S1210_REG_CONTROL,
> + AD2S1210_PHASE_LOCK_RANGE_44,
> + udata == 44 ? AD2S1210_PHASE_LOCK_RANGE_44 : 0);
> + if (ret < 0)
> + goto error_ret;
> +
> + ret = len;
> +
> +error_ret:
> + mutex_unlock(&st->lock);
> + return ret;
> +}
> +
> +static ssize_t phase_lock_range_available_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + return sprintf(buf, "44 360\n");
> +}
> +
> /* read the fault register since last sample */
> static ssize_t ad2s1210_show_fault(struct device *dev,
> struct device_attribute *attr, char *buf)
> @@ -506,6 +560,8 @@ static int ad2s1210_write_raw(struct iio_dev *indio_dev,
> }
>
> static IIO_DEVICE_ATTR_RW(excitation_frequency, 0);
> +static IIO_DEVICE_ATTR_RW(phase_lock_range, 0);
> +static IIO_DEVICE_ATTR_RO(phase_lock_range_available, 0);
> static IIO_DEVICE_ATTR(fault, 0644,
> ad2s1210_show_fault, ad2s1210_clear_fault, 0);
>
> @@ -552,6 +608,8 @@ static const struct iio_chan_spec ad2s1210_channels[] = {
>
> static struct attribute *ad2s1210_attributes[] = {
> &iio_dev_attr_excitation_frequency.dev_attr.attr,
> + &iio_dev_attr_phase_lock_range.dev_attr.attr,
> + &iio_dev_attr_phase_lock_range_available.dev_attr.attr,
> &iio_dev_attr_fault.dev_attr.attr,
> &iio_dev_attr_los_thrd.dev_attr.attr,
> &iio_dev_attr_dos_ovr_thrd.dev_attr.attr,
