staging: iio: ad9832: replace mlock with driver private lock

The IIO subsystem is redefining iio_dev->mlock to be used by
the IIO core only for protecting device operating mode changes.
ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.

In this driver, mlock was being used to protect hardware state
changes.  Replace it with a lock in the devices global data.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index 8d40c8e..425b8ab 100644 (file)
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -84,6 +84,7 @@
  * @freq_msg:          tuning word spi message
  * @phase_xfer:                tuning word spi transfer
  * @phase_msg:         tuning word spi message
+ * @lock               protect sensor state
  * @data:              spi transmit buffer
  * @phase_data:                tuning word spi transmit buffer
  * @freq_data:         tuning word spi transmit buffer
@@ -103,6 +104,7 @@ struct ad9832_state {
        struct spi_message              freq_msg;
        struct spi_transfer             phase_xfer[2];
        struct spi_message              phase_msg;
+       struct mutex                    lock;   /* protect sensor state */
        /*
         * DMA (thus cache coherency maintenance) requires the
         * transfer buffers to live in their own cache lines.
@@ -177,7 +179,7 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
        if (ret)
                goto error_ret;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&st->lock);
        switch ((u32)this_attr->address) {
        case AD9832_FREQ0HM:
        case AD9832_FREQ1HM:
@@ -238,7 +240,7 @@ static ssize_t ad9832_write(struct device *dev, struct device_attribute *attr,
        default:
                ret = -ENODEV;
        }
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&st->lock);
 
 error_ret:
        return ret ? ret : len;
@@ -334,6 +336,7 @@ static int ad9832_probe(struct spi_device *spi)
 
        st->mclk = pdata->mclk;
        st->spi = spi;
+       mutex_init(&st->lock);
 
        indio_dev->dev.parent = &spi->dev;
        indio_dev->name = spi_get_device_id(spi)->name;