staging: iio: adis16060: Remove iio_dev mlock and refactor code

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.

In the driver, buf_lock protects both the adis16060_spi_write() and
adis16060_spi_read() functions and both are always called in
pair. First write, then read. Refactor the code to have
one single function adis16060_spi_write_than_read() protected by
the buf_lock.  This removes the need for additional locking via
mlock, so this locking is removed.

Signed-off-by: simran singhal <singhalsimran0@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
index c9d46e7..8115962 100644 (file)
--- a/drivers/staging/iio/gyro/adis16060_core.c
+++ b/drivers/staging/iio/gyro/adis16060_core.c
@@ -40,25 +40,20 @@ struct adis16060_state {
 
 static struct iio_dev *adis16060_iio_dev;
 
-static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
+static int adis16060_spi_write_than_read(struct iio_dev *indio_dev,
+                                        u8 conf, u16 *val)
 {
        int ret;
        struct adis16060_state *st = iio_priv(indio_dev);
 
        mutex_lock(&st->buf_lock);
-       st->buf[2] = val; /* The last 8 bits clocked in are latched */
+       st->buf[2] = conf; /* The last 8 bits clocked in are latched */
        ret = spi_write(st->us_w, st->buf, 3);
-       mutex_unlock(&st->buf_lock);
-
-       return ret;
-}
-
-static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
-{
-       int ret;
-       struct adis16060_state *st = iio_priv(indio_dev);
 
-       mutex_lock(&st->buf_lock);
+       if (ret < 0) {
+               mutex_unlock(&st->buf_lock);
+               return ret;
+       }
 
        ret = spi_read(st->us_r, st->buf, 3);
 
@@ -86,17 +81,11 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
 
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
-               /* Take the iio_dev status lock */
-               mutex_lock(&indio_dev->mlock);
-               ret = adis16060_spi_write(indio_dev, chan->address);
+               ret = adis16060_spi_write_than_read(indio_dev,
+                                                   chan->address, &tval);
                if (ret < 0)
-                       goto out_unlock;
+                       return ret;
 
-               ret = adis16060_spi_read(indio_dev, &tval);
-               if (ret < 0)
-                       goto out_unlock;
-
-               mutex_unlock(&indio_dev->mlock);
                *val = tval;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_OFFSET:
@@ -110,10 +99,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
        }
 
        return -EINVAL;
-
-out_unlock:
-       mutex_unlock(&indio_dev->mlock);
-       return ret;
 }
 
 static const struct iio_info adis16060_info = {