[PATCH] iio: dac: ad5421: Replace indio_dev->mlock with own device lock

From: Sergiu Cuciurean
Date: Thu May 14 2020 - 05:18:31 EST


As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@xxxxxxxxxx>
---
drivers/iio/dac/ad5421.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/dac/ad5421.c b/drivers/iio/dac/ad5421.c
index 63063e85cd0a..fec27764cea8 100644
--- a/drivers/iio/dac/ad5421.c
+++ b/drivers/iio/dac/ad5421.c
@@ -62,12 +62,14 @@
* @current_range: current range which the device is configured for
* @data: spi transfer buffers
* @fault_mask: software masking of events
+ * @lock lock to protect the data buffer during SPI ops
*/
struct ad5421_state {
struct spi_device *spi;
unsigned int ctrl;
enum ad5421_current_range current_range;
unsigned int fault_mask;
+ struct mutex lock;

/*
* DMA (thus cache coherency maintenance) requires the
@@ -142,11 +144,12 @@ static int ad5421_write_unlocked(struct iio_dev *indio_dev,
static int ad5421_write(struct iio_dev *indio_dev, unsigned int reg,
unsigned int val)
{
+ struct ad5421_state *st = iio_priv(indio_dev);
int ret;

- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
ret = ad5421_write_unlocked(indio_dev, reg, val);
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);

return ret;
}
@@ -166,7 +169,7 @@ static int ad5421_read(struct iio_dev *indio_dev, unsigned int reg)
},
};

- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);

st->data[0].d32 = cpu_to_be32((1 << 23) | (reg << 16));

@@ -174,7 +177,7 @@ static int ad5421_read(struct iio_dev *indio_dev, unsigned int reg)
if (ret >= 0)
ret = be32_to_cpu(st->data[1].d32) & 0xffff;

- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);

return ret;
}
@@ -185,14 +188,14 @@ static int ad5421_update_ctrl(struct iio_dev *indio_dev, unsigned int set,
struct ad5421_state *st = iio_priv(indio_dev);
unsigned int ret;

- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);

st->ctrl &= ~clr;
st->ctrl |= set;

ret = ad5421_write_unlocked(indio_dev, AD5421_REG_CTRL, st->ctrl);

- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);

return ret;
}
@@ -400,12 +403,12 @@ static int ad5421_write_event_config(struct iio_dev *indio_dev,
return -EINVAL;
}

- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
if (state)
st->fault_mask |= mask;
else
st->fault_mask &= ~mask;
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);

return 0;
}
@@ -491,6 +494,8 @@ static int ad5421_probe(struct spi_device *spi)
indio_dev->channels = ad5421_channels;
indio_dev->num_channels = ARRAY_SIZE(ad5421_channels);

+ mutex_init(&st->lock);
+
st->ctrl = AD5421_CTRL_WATCHDOG_DISABLE |
AD5421_CTRL_AUTO_FAULT_READBACK;

--
2.17.1