iio:tcs3472: Check for buffer enabled and locking

Signed-off-by: Peter Meerwald <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 fe063a0a21cdd7a90a3d01d59c6aecaafb386a07..752569985d1dff295fb00df9723926b404a7dafb 100644 (file)
--- a/drivers/iio/light/tcs3472.c
+++ b/drivers/iio/light/tcs3472.c
@@ -52,6 +52,7 @@
 
 struct tcs3472_data {
        struct i2c_client *client;
+       struct mutex lock;
        u8 enable;
        u8 control;
        u8 atime;
@@ -116,10 +117,17 @@ 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 = tcs3472_req_data(data);
-               if (ret < 0)
+               if (ret < 0) {
+                       mutex_unlock(&data->lock);
                        return ret;
+               }
                ret = i2c_smbus_read_word_data(data->client, chan->address);
+               mutex_unlock(&data->lock);
                if (ret < 0)
                        return ret;
                *val = ret;
@@ -255,6 +263,7 @@ 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;