staging: iio: ad9834: Use private driver lock instead of mlock

iio_dev->mlock should be used by the IIO core only for protecting
device operating mode changes. ie. Changes between INDIO_DIRECT_MODE,
INDIO_BUFFER_* modes.
Replace mlock with a lock in the device's global data to protect
hardware state changes.

Signed-off-by: sayli karnik <karniksayli1995@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c
index f92ff7fef6f3c355b151e8d035499dd03bd3bf46..2dffe48035f3915fa6b3194c9669cd12b94ab7a5 100644 (file)
--- a/drivers/staging/iio/frequency/ad9834.c
+++ b/drivers/staging/iio/frequency/ad9834.c
@@ -63,6 +63,7 @@
  * @msg:               default spi message
  * @freq_xfer:         tuning word spi transfer
  * @freq_msg:          tuning word spi message
+ * @lock:              protect sensor state
  * @data:              spi transmit buffer
  * @freq_data:         tuning word spi transmit buffer
  */
@@ -77,6 +78,7 @@ struct ad9834_state {
        struct spi_message              msg;
        struct spi_transfer             freq_xfer[2];
        struct spi_message              freq_msg;
+       struct mutex                    lock;   /* protect sensor state */
 
        /*
         * DMA (thus cache coherency maintenance) requires the
@@ -149,7 +151,7 @@ static ssize_t ad9834_write(struct device *dev,
        if (ret)
                goto error_ret;
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&st->lock);
        switch ((u32)this_attr->address) {
        case AD9834_REG_FREQ0:
        case AD9834_REG_FREQ1:
@@ -207,7 +209,7 @@ static ssize_t ad9834_write(struct device *dev,
        default:
                ret = -ENODEV;
        }
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&st->lock);
 
 error_ret:
        return ret ? ret : len;
@@ -224,7 +226,7 @@ static ssize_t ad9834_store_wavetype(struct device *dev,
        int ret = 0;
        bool is_ad9833_7 = (st->devid == ID_AD9833) || (st->devid == ID_AD9837);
 
-       mutex_lock(&indio_dev->mlock);
+       mutex_lock(&st->lock);
 
        switch ((u32)this_attr->address) {
        case 0:
@@ -267,7 +269,7 @@ static ssize_t ad9834_store_wavetype(struct device *dev,
                st->data = cpu_to_be16(AD9834_REG_CMD | st->control);
                ret = spi_sync(st->spi, &st->msg);
        }
-       mutex_unlock(&indio_dev->mlock);
+       mutex_unlock(&st->lock);
 
        return ret ? ret : len;
 }
@@ -418,6 +420,7 @@ static int ad9834_probe(struct spi_device *spi)
        }
        spi_set_drvdata(spi, indio_dev);
        st = iio_priv(indio_dev);
+       mutex_init(&st->lock);
        st->mclk = pdata->mclk;
        st->spi = spi;
        st->devid = spi_get_device_id(spi)->driver_data;