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From:   Sergiu Cuciurean <sergiu.cuciurean@analog.com>
To:     <linux-kernel@vger.kernel.org>, <linux-iio@vger.kernel.org>
CC:     Sergiu Cuciurean <sergiu.cuciurean@analog.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Hartmut Knaack <knaack.h@gmx.de>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Fabrice Gasnier <fabrice.gasnier@st.com>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>
Subject: [PATCH] iio: stm32-dac: Replace indio_dev->mlock with own device lock
Date:   Thu, 14 May 2020 11:50:12 +0300
Message-ID: <20200514085018.79948-1-sergiu.cuciurean@analog.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
---
 drivers/iio/dac/stm32-dac.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/dac/stm32-dac.c b/drivers/iio/dac/stm32-dac.c
index f22c1d9129b2..74b9474c8590 100644
--- a/drivers/iio/dac/stm32-dac.c
+++ b/drivers/iio/dac/stm32-dac.c
@@ -26,9 +26,11 @@
 /**
  * struct stm32_dac - private data of DAC driver
  * @common:		reference to DAC common data
+ * @lock: lock to protect the data buffer during regmap ops
  */
 struct stm32_dac {
 	struct stm32_dac_common *common;
+	struct mutex		lock;
 };
 
 static int stm32_dac_is_enabled(struct iio_dev *indio_dev, int channel)
@@ -58,10 +60,10 @@ static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch,
 	int ret;
 
 	/* already enabled / disabled ? */
-	mutex_lock(&indio_dev->mlock);
+	mutex_lock(&dac->lock);
 	ret = stm32_dac_is_enabled(indio_dev, ch);
 	if (ret < 0 || enable == !!ret) {
-		mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&dac->lock);
 		return ret < 0 ? ret : 0;
 	}
 
@@ -69,13 +71,13 @@ static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch,
 		ret = pm_runtime_get_sync(dev);
 		if (ret < 0) {
 			pm_runtime_put_noidle(dev);
-			mutex_unlock(&indio_dev->mlock);
+			mutex_unlock(&dac->lock);
 			return ret;
 		}
 	}
 
 	ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, msk, en);
-	mutex_unlock(&indio_dev->mlock);
+	mutex_unlock(&dac->lock);
 	if (ret < 0) {
 		dev_err(&indio_dev->dev, "%s failed\n", en ?
 			"Enable" : "Disable");
@@ -328,6 +330,8 @@ static int stm32_dac_probe(struct platform_device *pdev)
 	indio_dev->info = &stm32_dac_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
+	mutex_init(&dac->lock);
+
 	ret = stm32_dac_chan_of_init(indio_dev);
 	if (ret < 0)
 		return ret;
-- 
2.17.1