linux-kernel - [PATCH] iio: adc: ad7793: use iio helper function to guarantee direct mode

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Date:	Mon, 18 Jul 2016 12:35:24 -0700
From:	Alison Schofield <amsfield22@...il.com>
To:	jic23@...nel.org
Cc:	Michael.Hennerich@...log.com, knaack.h@....de, lars@...afoo.de,
	pmeerw@...erw.net, linux-iio@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] iio: adc: ad7793: 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.

Signed-off-by: Alison Schofield <amsfield22@...il.com>
Cc: Daniel Baluta <daniel.baluta@...il.com>
---
This driver is not doing any error checking on the code I just wrapped
in device_claim/release.  It first saves info to the global state and
then writes it to a register, with no error checking. 

Does similar in both *write_raw, and *write_frequency.  

I could add error checking in another patch if it's desired. I don't have
this sensor to verify.  Let me know if that would be welcome. Thanks!


 drivers/iio/adc/ad7793.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
index 847789b..e6706a0 100644
--- a/drivers/iio/adc/ad7793.c
+++ b/drivers/iio/adc/ad7793.c
@@ -519,11 +519,9 @@ static int ad7793_write_raw(struct iio_dev *indio_dev,
 	int ret, i;
 	unsigned int tmp;
 
-	mutex_lock(&indio_dev->mlock);
-	if (iio_buffer_enabled(indio_dev)) {
-		mutex_unlock(&indio_dev->mlock);
-		return -EBUSY;
-	}
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
@@ -548,7 +546,7 @@ static int ad7793_write_raw(struct iio_dev *indio_dev,
 		ret = -EINVAL;
 	}
 
-	mutex_unlock(&indio_dev->mlock);
+	iio_device_release_direct_mode(indio_dev);
 	return ret;
 }
 
-- 
2.1.4