Commit 5187e03b authored by Oleksij Rempel's avatar Oleksij Rempel Committed by Jonathan Cameron
Browse files

iio: dac: ds4424: reject -128 RAW value 



The DS442x DAC uses sign-magnitude encoding, so -128 cannot be represented
in hardware (7-bit magnitude).

Previously, passing -128 resulted in a truncated value that programmed
0mA (magnitude 0) instead of the expected maximum negative current,
effectively failing silently.

Reject -128 to avoid producing the wrong current.

Fixes: d632a2bd ("iio: dac: ds4422/ds4424 dac driver")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 7ef74d96

drivers/iio/dac/ds4424.c

+1 −1
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ static int ds4424_write_raw(struct iio_dev *indio_dev, 


	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (val < S8_MIN || val > S8_MAX)

		if (val <= S8_MIN || val > S8_MAX)

			return -EINVAL;



		if (val > 0) {