[PATCH 1/2] iio: adc: ti-ads1298: Add safe usage guarantee for device communication

[Arthur-Prince <r2.arthur.prince@gmail.com>]

Add safe usage guarantee for device communication in 
ads1298_reg_access/ ads1298_write_raw (ti-ads1298) that 
prevent simultaneous read/write operations.

Signed-off-by: Arthur-Prince <r2.arthur.prince@gmail.com>
Co-developed-by: Mariana Valério <mariana.valerio2@hotmail.com>
Signed-off-by: Mariana Valério <mariana.valerio2@hotmail.com>
---
 drivers/iio/adc/ti-ads1298.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/ti-ads1298.c b/drivers/iio/adc/ti-ads1298.c
index 03f762415fa5..438bcc3c74da 100644
--- a/drivers/iio/adc/ti-ads1298.c
+++ b/drivers/iio/adc/ti-ads1298.c
@@ -355,9 +355,19 @@ static int ads1298_write_raw(struct iio_dev *indio_dev,
 {
 	struct ads1298_private *priv = iio_priv(indio_dev);
 
+	int ret;
+
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		return ads1298_set_samp_freq(priv, val);
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
+		ret = ads1298_set_samp_freq(priv, val);
+
+		iio_device_release_direct_mode(indio_dev);
+
+		return ret;
 	default:
 		return -EINVAL;
 	}
@@ -417,10 +427,17 @@ static int ads1298_reg_access(struct iio_dev *indio_dev, unsigned int reg,
 {
 	struct ads1298_private *priv = iio_priv(indio_dev);
 
+	int ret;
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 	if (readval)
-		return regmap_read(priv->regmap, reg, readval);
-
-	return regmap_write(priv->regmap, reg, writeval);
+		ret = regmap_read(priv->regmap, reg, readval);
+	else
+		ret = regmap_write(priv->regmap, reg, writeval);
+	
+	iio_device_release_direct_mode(indio_dev);
+	return ret;
 }
 
 static void ads1298_rdata_unmark_busy(struct ads1298_private *priv)
-- 
2.45.2