iio: dac: mcp4922: fix error handling in mcp4922_write_raw

[ Upstream commit 0833627fc3 ]

Do not try to write negative values and make sure that the write goes well.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Marcus Folkesson 2018-08-24 22:24:40 +02:00 committed by Greg Kroah-Hartman
parent 502e825baa
commit bd0e3c12a0

View file

@ -94,17 +94,22 @@ static int mcp4922_write_raw(struct iio_dev *indio_dev,
long mask)
{
struct mcp4922_state *state = iio_priv(indio_dev);
int ret;
if (val2 != 0)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val > GENMASK(chan->scan_type.realbits-1, 0))
if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0))
return -EINVAL;
val <<= chan->scan_type.shift;
state->value[chan->channel] = val;
return mcp4922_spi_write(state, chan->channel, val);
ret = mcp4922_spi_write(state, chan->channel, val);
if (!ret)
state->value[chan->channel] = val;
return ret;
default:
return -EINVAL;
}