iio: light: tcs3472: 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 previous race condition when a buffer is enabled whilst
a raw 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>

diff --git a/drivers/iio/light/tcs3472.c b/drivers/iio/light/tcs3472.c
index 1b530bf..b29312f 100644 (file)
--- a/drivers/iio/light/tcs3472.c
+++ b/drivers/iio/light/tcs3472.c
@@ -52,7 +52,6 @@
 
 struct tcs3472_data {
        struct i2c_client *client;
-       struct mutex lock;
        u8 enable;
        u8 control;
        u8 atime;
@@ -117,17 +116,16 @@ static int tcs3472_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 = tcs3472_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;
@@ -263,7 +261,6 @@ static int tcs3472_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 = &tcs3472_info;