On 23, March 2018 14:27, Jonathan Cameron wrote: > 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. I'm sorry, I misunderstood our previous discussing on this topic (https://marc.info/?l=linux-iio&m=152087432322446&w=2) as saying: "there already exists another channel type that is a good enough match". The in_incli and in_rot_from_* family all use degrees as their unit. For V2 I'll change it back to an angle channel and use angle as its unit. Best regards, David Veenstra > > 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, -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
