From d3e6ed841671de3b25776b5e91f33112e8f5bca6 Mon Sep 17 00:00:00 2001 From: David Veenstra Date: Fri, 18 May 2018 20:23:01 +0200 Subject: [PATCH] staging: iio: ad2s1200: Add scaling factor for angular velocity channel The sysfs iio ABI states radians per second is expected as the unit for angular velocity, but the 12-bit angular velocity register has revolution per seconds as its unit. So a scaling factor of approximately 2 * Pi is added to the angular velocity channel. Signed-off-by: David Veenstra Signed-off-by: Jonathan Cameron --- drivers/staging/iio/resolver/ad2s1200.c | 71 +++++++++++++++++++++------------ 1 file changed, 45 insertions(+), 26 deletions(-) diff --git a/drivers/staging/iio/resolver/ad2s1200.c b/drivers/staging/iio/resolver/ad2s1200.c index 67d9747..7b8af55 100644 --- a/drivers/staging/iio/resolver/ad2s1200.c +++ b/drivers/staging/iio/resolver/ad2s1200.c @@ -55,37 +55,55 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev, struct ad2s1200_state *st = iio_priv(indio_dev); int ret; - mutex_lock(&st->lock); - gpiod_set_value(st->sample, 0); - - /* delay (6 * AD2S1200_TSCLK + 20) nano seconds */ - udelay(1); - gpiod_set_value(st->sample, 1); - gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL)); - - ret = spi_read(st->sdev, &st->rx, 2); - if (ret < 0) { + switch (m) { + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_ANGL_VEL: + /* 2 * Pi ~= 6.283185 */ + *val = 6; + *val2 = 283185; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } + break; + case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); + gpiod_set_value(st->sample, 0); + + /* delay (6 * AD2S1200_TSCLK + 20) nano seconds */ + udelay(1); + gpiod_set_value(st->sample, 1); + gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL)); + + ret = spi_read(st->sdev, &st->rx, 2); + if (ret < 0) { + mutex_unlock(&st->lock); + return ret; + } + + switch (chan->type) { + case IIO_ANGL: + *val = be16_to_cpup(&st->rx) >> 4; + break; + case IIO_ANGL_VEL: + *val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11); + break; + default: + mutex_unlock(&st->lock); + return -EINVAL; + } + + /* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */ + udelay(1); mutex_unlock(&st->lock); - return ret; - } - switch (chan->type) { - case IIO_ANGL: - *val = be16_to_cpup(&st->rx) >> 4; - break; - case IIO_ANGL_VEL: - *val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11); - break; + return IIO_VAL_INT; default: - mutex_unlock(&st->lock); - return -EINVAL; + break; } - /* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */ - udelay(1); - mutex_unlock(&st->lock); - - return IIO_VAL_INT; + return -EINVAL; } static const struct iio_chan_spec ad2s1200_channels[] = { @@ -99,6 +117,7 @@ static const struct iio_chan_spec ad2s1200_channels[] = { .indexed = 1, .channel = 0, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), } }; -- 2.7.4