From af7cc8ebab4aade6b2a1860b31bbdda3c9739ecc Mon Sep 17 00:00:00 2001 From: Mircea Caprioru Date: Thu, 6 Dec 2018 15:53:15 +0200 Subject: [PATCH] iio: dac: ad5686: fix bit shift read register commit 0e76df5c978338f3051e5126fc0c4245c57a307a upstream. This patch solves the register readback issue with the bit shift. When the dac resolution was lower than the register size (ex. 12 bits out of 16 bits) the readback value was not shifted with the difference in bits and the value was higher. Also a mask is applied on the read value in order to get the value relative to the actual bit size. Fixes: 0357e488b8 ("iio:dac:ad5686: Refactor the driver") Signed-off-by: Mircea Caprioru Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/dac/ad5686.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c index 2ddbfc3..cba62ad2 100644 --- a/drivers/iio/dac/ad5686.c +++ b/drivers/iio/dac/ad5686.c @@ -124,7 +124,8 @@ static int ad5686_read_raw(struct iio_dev *indio_dev, mutex_unlock(&indio_dev->mlock); if (ret < 0) return ret; - *val = ret; + *val = (ret >> chan->scan_type.shift) & + GENMASK(chan->scan_type.realbits - 1, 0); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = st->vref_mv; -- 2.7.4