From: Alexandru Ardelean alexandru.ardelean@analog.com
[ Upstream commit c991bf9b650f39481cf3c1137092d4754a2c75de ]
This change replaces indio_dev's mlock with the driver's own lock. The lock is mostly needed to protect state when changing the `dac_cache` info. The lock has been extended to `ad7303_read_raw()`, to make sure that the cache is updated if an SPI-write is already in progress.
Signed-off-by: Alexandru Ardelean alexandru.ardelean@analog.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/dac/ad7303.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/dac/ad7303.c b/drivers/iio/dac/ad7303.c index 8f3bd19b6dc35..dc1aea5b579e4 100644 --- a/drivers/iio/dac/ad7303.c +++ b/drivers/iio/dac/ad7303.c @@ -42,6 +42,7 @@ struct ad7303_state { struct regulator *vdd_reg; struct regulator *vref_reg;
+ struct mutex lock; /* * DMA (thus cache coherency maintenance) requires the * transfer buffers to live in their own cache lines. @@ -80,7 +81,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, if (ret) return ret;
- mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock);
if (pwr_down) st->config |= AD7303_CFG_POWER_DOWN(chan->channel); @@ -91,7 +92,7 @@ static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, * mode, so just write one of the DAC channels again */ ad7303_write(st, chan->channel, st->dac_cache[chan->channel]);
- mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); return len; }
@@ -117,7 +118,9 @@ static int ad7303_read_raw(struct iio_dev *indio_dev,
switch (info) { case IIO_CHAN_INFO_RAW: + mutex_lock(&st->lock); *val = st->dac_cache[chan->channel]; + mutex_unlock(&st->lock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: vref_uv = ad7303_get_vref(st, chan); @@ -145,11 +148,11 @@ static int ad7303_write_raw(struct iio_dev *indio_dev, if (val >= (1 << chan->scan_type.realbits) || val < 0) return -EINVAL;
- mutex_lock(&indio_dev->mlock); + mutex_lock(&st->lock); ret = ad7303_write(st, chan->address, val); if (ret == 0) st->dac_cache[chan->channel] = val; - mutex_unlock(&indio_dev->mlock); + mutex_unlock(&st->lock); break; default: ret = -EINVAL; @@ -212,6 +215,8 @@ static int ad7303_probe(struct spi_device *spi)
st->spi = spi;
+ mutex_init(&st->lock); + st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd"); if (IS_ERR(st->vdd_reg)) return PTR_ERR(st->vdd_reg);