From 07ffd0d071153aa45205891e0e577aaba1d74d0f Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 25 Apr 2012 09:44:52 +0200 Subject: [PATCH] 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 --- drivers/staging/iio/dac/ad5446.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/staging/iio/dac/ad5446.c b/drivers/staging/iio/dac/ad5446.c index ec6968b2f05..de796c2f0b2 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: -- 2.46.0