[PATCH 06/15] iio: adc: ltc2947-core: do not use internal iio_dev lock

From: "Nuno Sá" <nuno.sa@analog.com>
To: <linux-arm-kernel@lists.infradead.org>,
	<linux-rockchip@lists.infradead.org>,
	<linux-amlogic@lists.infradead.org>, <linux-imx@nxp.com>,
	<linux-iio@vger.kernel.org>
Cc: "Chunyan Zhang" <zhang.lyra@gmail.com>,
	"Michael Hennerich" <Michael.Hennerich@analog.com>,
	"Martin Blumenstingl" <martin.blumenstingl@googlemail.com>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Cixi Geng" <cixi.geng1@unisoc.com>,
	"Kevin Hilman" <khilman@baylibre.com>,
	"Vladimir Zapolskiy" <vz@mleia.com>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Alexandru Ardelean" <aardelean@deviqon.com>,
	"Fabio Estevam" <festevam@gmail.com>,
	"Andriy Tryshnivskyy" <andriy.tryshnivskyy@opensynergy.com>,
	"Haibo Chen" <haibo.chen@nxp.com>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Hans de Goede" <hdegoede@redhat.com>,
	"Miquel Raynal" <miquel.raynal@bootlin.com>,
	"Jerome Brunet" <jbrunet@baylibre.com>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Florian Boor" <florian.boor@kernelconcepts.de>,
	"Ciprian Regus" <ciprian.regus@analog.com>,
	"Lars-Peter Clausen" <lars@metafoo.de>,
	"Andy Shevchenko" <andy.shevchenko@gmail.com>,
	"Jonathan Cameron" <jic23@kernel.org>,
	"Neil Armstrong" <narmstrong@baylibre.com>,
	"Baolin Wang" <baolin.wang@linux.alibaba.com>,
	"Jyoti Bhayana" <jbhayana@google.com>,
	"Nuno Sá" <nuno.sa@analog.com>, "Chen-Yu Tsai" <wens@csie.org>,
	"Orson Zhai" <orsonzhai@gmail.com>
Subject: [PATCH 06/15] iio: adc: ltc2947-core: do not use internal iio_dev lock
Date: Tue, 20 Sep 2022 13:28:12 +0200	[thread overview]
Message-ID: <20220920112821.975359-7-nuno.sa@analog.com> (raw)
In-Reply-To: <20220920112821.975359-1-nuno.sa@analog.com>

The iio_device lock is only meant for internal use. Hence define a
device local lock to protect against concurrent accesses.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
 drivers/iio/adc/ltc2497-core.c | 7 +++++--
 drivers/iio/adc/ltc2497.h      | 2 ++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c
index f52d37af4d1f..00536501dc52 100644
--- a/drivers/iio/adc/ltc2497-core.c
+++ b/drivers/iio/adc/ltc2497-core.c
@@ -10,6 +10,7 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/driver.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/regulator/consumer.h>
 
 #include "ltc2497.h"
@@ -81,9 +82,9 @@ static int ltc2497core_read_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		mutex_lock(&indio_dev->mlock);
+		mutex_lock(&ddata->lock);
 		ret = ltc2497core_read(ddata, chan->address, val);
-		mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&ddata->lock);
 		if (ret < 0)
 			return ret;
 
@@ -169,6 +170,8 @@ int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
 	struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
 	int ret;
 
+	mutex_init(&ddata->lock);
+
 	/*
 	 * Keep using dev_name() for the iio_dev's name on some of the parts,
 	 * since updating it would result in a ABI breakage.
diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
index e023de0d88c4..781519b52475 100644
--- a/drivers/iio/adc/ltc2497.h
+++ b/drivers/iio/adc/ltc2497.h
@@ -12,6 +12,8 @@ struct ltc2497_chip_info {
 struct ltc2497core_driverdata {
 	struct regulator *ref;
 	ktime_t	time_prev;
+	/* lock to protect against multiple access to the device */
+	struct mutex lock;
 	const struct ltc2497_chip_info	*chip_info;
 	u8 addr_prev;
 	int (*result_and_measure)(struct ltc2497core_driverdata *ddata,
-- 
2.37.3


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