From 680f8ea0e85c5c3a7283be99435d6461e8725348 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Fri, 10 Aug 2012 17:36:00 +0100 Subject: [PATCH] staging:iio:ad7793: Report channel offset In bipolar mode there is a a binary offset of 2**(N-1) (with N being the number of bits) on the reported value. Currently this value is subtracted when doing a manual read. While this works for manual channel readings it does not work for buffered mode. So report the offset in the channels offset property, which will work in both modes. Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/staging/iio/adc/ad7793.c | 39 +++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 13 deletions(-) diff --git a/drivers/staging/iio/adc/ad7793.c b/drivers/staging/iio/adc/ad7793.c index 5e457a4b4232..56014a8b6876 100644 --- a/drivers/staging/iio/adc/ad7793.c +++ b/drivers/staging/iio/adc/ad7793.c @@ -604,9 +604,6 @@ static int ad7793_read_raw(struct iio_dev *indio_dev, *val = (smpl >> chan->scan_type.shift) & ((1 << (chan->scan_type.realbits)) - 1); - if (!unipolar) - *val -= (1 << (chan->scan_type.realbits - 1)); - return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: @@ -639,6 +636,12 @@ static int ad7793_read_raw(struct iio_dev *indio_dev, *val = scale_uv; return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_OFFSET: + if (!unipolar) + *val -= (1 << (chan->scan_type.realbits - 1)); + else + *val = 0; + return IIO_VAL_INT; } return -EINVAL; } @@ -720,7 +723,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 0, .address = AD7793_CH_AIN1P_AIN1M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 0, .scan_type = IIO_ST('u', 24, 32, 0) }, @@ -732,7 +736,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 1, .address = AD7793_CH_AIN2P_AIN2M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 1, .scan_type = IIO_ST('u', 24, 32, 0) }, @@ -744,7 +749,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 2, .address = AD7793_CH_AIN3P_AIN3M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 2, .scan_type = IIO_ST('u', 24, 32, 0) }, @@ -757,7 +763,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 2, .address = AD7793_CH_AIN1M_AIN1M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 3, .scan_type = IIO_ST('u', 24, 32, 0) }, @@ -778,7 +785,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel = 4, .address = AD7793_CH_AVDD_MONITOR, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SEPARATE_BIT, + IIO_CHAN_INFO_SCALE_SEPARATE_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 5, .scan_type = IIO_ST('u', 24, 32, 0), }, @@ -793,7 +801,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 0, .address = AD7793_CH_AIN1P_AIN1M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 0, .scan_type = IIO_ST('u', 16, 32, 0) }, @@ -805,7 +814,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 1, .address = AD7793_CH_AIN2P_AIN2M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 1, .scan_type = IIO_ST('u', 16, 32, 0) }, @@ -817,7 +827,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 2, .address = AD7793_CH_AIN3P_AIN3M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 2, .scan_type = IIO_ST('u', 16, 32, 0) }, @@ -830,7 +841,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel2 = 2, .address = AD7793_CH_AIN1M_AIN1M, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SHARED_BIT, + IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 3, .scan_type = IIO_ST('u', 16, 32, 0) }, @@ -851,7 +863,8 @@ static const struct ad7793_chip_info ad7793_chip_info_tbl[] = { .channel = 4, .address = AD7793_CH_AVDD_MONITOR, .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | - IIO_CHAN_INFO_SCALE_SEPARATE_BIT, + IIO_CHAN_INFO_SCALE_SEPARATE_BIT | + IIO_CHAN_INFO_OFFSET_SHARED_BIT, .scan_index = 5, .scan_type = IIO_ST('u', 16, 32, 0), },