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authorLars-Peter Clausen <lars@metafoo.de>2012-08-10 17:36:00 +0100
committerJonathan Cameron <jic23@kernel.org>2012-08-16 20:24:34 +0100
commit680f8ea0e85c5c3a7283be99435d6461e8725348 (patch)
treef7a1ec3672c23a0d21cd36d82995643566d7bb19
parente83539092c390c95e30b0d9e434709f195340f80 (diff)
downloadlinux-680f8ea0e85c5c3a7283be99435d6461e8725348.tar.bz2
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 <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r--drivers/staging/iio/adc/ad7793.c39
1 files 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),
},