From: Peter Meerwald <p.meerwald@bct-electronic.com>
Date: Wed, 7 May 2014 12:38:00 +0000 (+0100)
Subject: iio:tcs3472: Check for buffer enabled and locking
X-Git-Tag: firefly_0821_release~176^2~3629^2^2~1
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2a58b4f88e3e51619916e9d090cbd1bb8d12b632;p=firefly-linux-kernel-4.4.55.git

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 fe063a0a21cd..752569985d1d 100644
--- 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;