iio: light: tcs3414: use iio helper function to guarantee direct mode

Replace the code that guarantees the device stays in direct mode
with iio_device_claim_direct_mode() which does same.  This allows
removal of an unused lock in the device private global data.

Also prevents a possible race around a buffer being enabled whilst
a read is going on.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Acked-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 5 insertions, 7 deletions

diff --git a/drivers/iio/light/tcs3414.c b/drivers/iio/light/tcs3414.c
index f90f8c5919fe..8a15fb541dc3 100644
--- a/drivers/iio/light/tcs3414.c
+++ b/drivers/iio/light/tcs3414.c
@@ -53,7 +53,6 @@
 
 struct tcs3414_data {
         struct i2c_client *client;
-        struct mutex lock;
         u8 control;
         u8 gain;
         u8 timing;
@@ -134,16 +133,16 @@ static int tcs3414_read_raw(struct iio_dev *indio_dev,
 
         switch (mask) {
         case IIO_CHAN_INFO_RAW:
-                if (iio_buffer_enabled(indio_dev))
-                        return -EBUSY;
-                mutex_lock(&data->lock);
+                ret = iio_device_claim_direct_mode(indio_dev);
+                if (ret)
+                        return ret;
                 ret = tcs3414_req_data(data);
                 if (ret < 0) {
-                        mutex_unlock(&data->lock);
+                        iio_device_release_direct_mode(indio_dev);
                         return ret;
                 }
                 ret = i2c_smbus_read_word_data(data->client, chan->address);
-                mutex_unlock(&data->lock);
+                iio_device_release_direct_mode(indio_dev);
                 if (ret < 0)
                         return ret;
                 *val = ret;
@@ -288,7 +287,6 @@ static int tcs3414_probe(struct i2c_client *client,
         data = iio_priv(indio_dev);
         i2c_set_clientdata(client, indio_dev);
         data->client = client;
-        mutex_init(&data->lock);
 
         indio_dev->dev.parent = &client->dev;
         indio_dev->info = &tcs3414_info;