From: Lars-Peter Clausen Date: Wed, 25 Apr 2012 07:44:52 +0000 (+0200) Subject: staging:iio:dac:ad5446: Do not exit powerdown when writing a sample X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=07ffd0d071153aa45205891e0e577aaba1d74d0f;p=deliverable%2Flinux.git staging:iio:dac:ad5446: Do not exit powerdown when writing a sample Both the powerdown mode bits and the sample value are stored in the same register, so writing a sample while the device is powered down will clear the power down bits. To avoid this only update the cached value when the device is powered down. Signed-off-by: Lars-Peter Clausen Acked-by: Jonathan Cameron ---- v1 actually had a small bug in that it would still write to the device's register when the sample was updated while the device was powered down. This was not critical since it would send out the powerdown mode again. Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/iio/dac/ad5446.c b/drivers/staging/iio/dac/ad5446.c index ec6968b2f054..de796c2f0b22 100644 --- a/drivers/staging/iio/dac/ad5446.c +++ b/drivers/staging/iio/dac/ad5446.c @@ -272,7 +272,7 @@ static int ad5446_write_raw(struct iio_dev *indio_dev, long mask) { struct ad5446_state *st = iio_priv(indio_dev); - int ret; + int ret = 0; switch (mask) { case IIO_CHAN_INFO_RAW: @@ -282,8 +282,10 @@ static int ad5446_write_raw(struct iio_dev *indio_dev, val <<= chan->scan_type.shift; mutex_lock(&indio_dev->mlock); st->cached_val = val; - st->chip_info->store_sample(st, val); - ret = spi_sync(st->spi, &st->msg); + if (!st->pwr_down) { + st->chip_info->store_sample(st, val); + ret = spi_sync(st->spi, &st->msg); + } mutex_unlock(&indio_dev->mlock); break; default: