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| author | Alexandru Ardelean <alexandru.ardelean@analog.com> | 2019-10-07 11:26:42 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2019-10-15 21:11:07 +0100 |
| commit | c991bf9b650f39481cf3c1137092d4754a2c75de (patch) | |
| tree | 44d5814ea986511ece954ab0b627821c7ada2bea | |
| parent | af8dc7bf4ea2bbef4b4b87f3f29c139fe4561d6e (diff) | |
| download | linux-c991bf9b650f39481cf3c1137092d4754a2c75de.tar.bz2 | |
iio: dac: ad7303: replace mlock with own lock
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>
| -rw-r--r-- | drivers/iio/dac/ad7303.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/iio/dac/ad7303.c b/drivers/iio/dac/ad7303.c index 8de9f40226e6..14bbac6bee98 100644 --- a/drivers/iio/dac/ad7303.c +++ b/drivers/iio/dac/ad7303.c @@ -41,6 +41,7 @@ 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. @@ -79,7 +80,7 @@ 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); @@ -90,7 +91,7 @@ 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; } @@ -116,7 +117,9 @@ 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); @@ -144,11 +147,11 @@ 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; @@ -211,6 +214,8 @@ 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); |