On Sun, 18 Mar 2018 14:37:04 +0100
David Veenstra <davidjulianveenstra@xxxxxxxxx> wrote:
> The angle channel is not defined in sysfs iio ABI. So it is replaced
> with an inclination channel, because it is defined in the ABI, and has the
> semantics of an angle.
>
> In addition, a fractional scaling factor of 360 / (2^12 -1) is added,
> to scale the 12-bits angular position to degrees, conform the ABI.
>
> Signed-off-by: David Veenstra <davidjulianveenstra@xxxxxxxxx>
No, please do not blugeon a device into the existing documented ABI.
A resolver does not measure something that can be remotely
sensibly mapped to inclination. Inclination is relative to 'down'.
A resolver doesn't care about down.
Add an angle type to the ABI docs. It simply hasn't been documented
before because there were no drivers outside staging that use it.
Jonathan
> ---
> drivers/staging/iio/resolver/ad2s1200.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/iio/resolver/ad2s1200.c b/drivers/staging/iio/resolver/ad2s1200.c
> index 4b97a106012c..937676bcc0d4 100644
> --- a/drivers/staging/iio/resolver/ad2s1200.c
> +++ b/drivers/staging/iio/resolver/ad2s1200.c
> @@ -64,6 +64,10 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
> switch (m) {
> case IIO_CHAN_INFO_SCALE:
> switch (chan->type) {
> + case IIO_INCLI:
> + *val = 360;
> + *val2 = 0xFFF;
> + return IIO_VAL_FRACTIONAL;
> case IIO_ANGL_VEL:
> /*
> * 2 * Pi is almost equal to
> @@ -91,7 +95,7 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
> /* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
> udelay(1);
> gpiod_set_value(st->sample, 1);
> - gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
> + gpiod_set_value(st->rdvel, !!(chan->type == IIO_INCLI));
>
> ret = spi_read(st->sdev, st->rx, 2);
> if (ret < 0) {
> @@ -101,7 +105,7 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
>
> vel = be16_to_cpup((__be16 *)st->rx);
> switch (chan->type) {
> - case IIO_ANGL:
> + case IIO_INCLI:
> *val = vel >> 4;
> ret = IIO_VAL_INT;
> break;
> @@ -128,10 +132,11 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
>
> static const struct iio_chan_spec ad2s1200_channels[] = {
> {
> - .type = IIO_ANGL,
> + .type = IIO_INCLI,
> .indexed = 1,
> .channel = 0,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
> }, {
> .type = IIO_ANGL_VEL,
> .indexed = 1,
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