iio:adc:ad799x: Fix reading and writing of event values, apply shift
last two bits of ADC and limit values are zero and should not be reported
(ad7993, ad7997); compare with read_raw()
event values are 10 (ad7993, ad7997) or 12 bit max., check the range on write
Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Stable@vger.kernel.org
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c
index 39b4cb4..6eba301 100644
--- a/drivers/iio/adc/ad799x.c
+++ b/drivers/iio/adc/ad799x.c
@@ -427,9 +427,12 @@
int ret;
struct ad799x_state *st = iio_priv(indio_dev);
+ if (val < 0 || val > RES_MASK(chan->scan_type.realbits))
+ return -EINVAL;
+
mutex_lock(&indio_dev->mlock);
ret = ad799x_i2c_write16(st, ad799x_threshold_reg(chan, dir, info),
- val);
+ val << chan->scan_type.shift);
mutex_unlock(&indio_dev->mlock);
return ret;
@@ -452,7 +455,8 @@
mutex_unlock(&indio_dev->mlock);
if (ret < 0)
return ret;
- *val = valin;
+ *val = (valin >> chan->scan_type.shift) &
+ RES_MASK(chan->scan_type.realbits);
return IIO_VAL_INT;
}