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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>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Michael Hennerich <Michael.Hennerich@analog.com>,
        Stefan Popa <stefan.popa@analog.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Hartmut Knaack <knaack.h@gmx.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Subject: [PATCH v2] iio: dac: ad5592r-base: Replace indio_dev->mlock with own device lock
Date:   Wed, 20 May 2020 15:02:01 +0300
Message-ID: <20200520120207.46034-1-sergiu.cuciurean@analog.com>
In-Reply-To: <20200520061819.29056-1-sergiu.cuciurean@analog.com>
References: <20200520061819.29056-1-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.
This also removes unused iio_dev pointers.

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
---
 drivers/iio/dac/ad5592r-base.c | 30 +++++++++++++++---------------
 drivers/iio/dac/ad5592r-base.h |  1 +
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/iio/dac/ad5592r-base.c b/drivers/iio/dac/ad5592r-base.c
index e2110113e884..410e90e5f75f 100644
--- a/drivers/iio/dac/ad5592r-base.c
+++ b/drivers/iio/dac/ad5592r-base.c
@@ -156,7 +156,6 @@ static void ad5592r_gpio_cleanup(struct ad5592r_state *st)
 static int ad5592r_reset(struct ad5592r_state *st)
 {
 	struct gpio_desc *gpio;
-	struct iio_dev *iio_dev = iio_priv_to_dev(st);
 
 	gpio = devm_gpiod_get_optional(st->dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(gpio))
@@ -166,10 +165,10 @@ static int ad5592r_reset(struct ad5592r_state *st)
 		udelay(1);
 		gpiod_set_value(gpio, 1);
 	} else {
-		mutex_lock(&iio_dev->mlock);
+		mutex_lock(&st->lock);
 		/* Writing this magic value resets the device */
 		st->ops->reg_write(st, AD5592R_REG_RESET, 0xdac);
-		mutex_unlock(&iio_dev->mlock);
+		mutex_unlock(&st->lock);
 	}
 
 	udelay(250);
@@ -197,7 +196,6 @@ static int ad5592r_set_channel_modes(struct ad5592r_state *st)
 	const struct ad5592r_rw_ops *ops = st->ops;
 	int ret;
 	unsigned i;
-	struct iio_dev *iio_dev = iio_priv_to_dev(st);
 	u8 pulldown = 0, tristate = 0, dac = 0, adc = 0;
 	u16 read_back;
 
@@ -247,7 +245,7 @@ static int ad5592r_set_channel_modes(struct ad5592r_state *st)
 		}
 	}
 
-	mutex_lock(&iio_dev->mlock);
+	mutex_lock(&st->lock);
 
 	/* Pull down unused pins to GND */
 	ret = ops->reg_write(st, AD5592R_REG_PULLDOWN, pulldown);
@@ -285,7 +283,7 @@ static int ad5592r_set_channel_modes(struct ad5592r_state *st)
 		ret = -EIO;
 
 err_unlock:
-	mutex_unlock(&iio_dev->mlock);
+	mutex_unlock(&st->lock);
 	return ret;
 }
 
@@ -314,11 +312,11 @@ static int ad5592r_write_raw(struct iio_dev *iio_dev,
 		if (!chan->output)
 			return -EINVAL;
 
-		mutex_lock(&iio_dev->mlock);
+		mutex_lock(&st->lock);
 		ret = st->ops->write_dac(st, chan->channel, val);
 		if (!ret)
 			st->cached_dac[chan->channel] = val;
-		mutex_unlock(&iio_dev->mlock);
+		mutex_unlock(&st->lock);
 		return ret;
 	case IIO_CHAN_INFO_SCALE:
 		if (chan->type == IIO_VOLTAGE) {
@@ -333,12 +331,12 @@ static int ad5592r_write_raw(struct iio_dev *iio_dev,
 			else
 				return -EINVAL;
 
-			mutex_lock(&iio_dev->mlock);
+			mutex_lock(&st->lock);
 
 			ret = st->ops->reg_read(st, AD5592R_REG_CTRL,
 						&st->cached_gp_ctrl);
 			if (ret < 0) {
-				mutex_unlock(&iio_dev->mlock);
+				mutex_unlock(&st->lock);
 				return ret;
 			}
 
@@ -360,7 +358,7 @@ static int ad5592r_write_raw(struct iio_dev *iio_dev,
 
 			ret = st->ops->reg_write(st, AD5592R_REG_CTRL,
 						 st->cached_gp_ctrl);
-			mutex_unlock(&iio_dev->mlock);
+			mutex_unlock(&st->lock);
 
 			return ret;
 		}
@@ -382,7 +380,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
 
 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
-		mutex_lock(&iio_dev->mlock);
+		mutex_lock(&st->lock);
 
 		if (!chan->output) {
 			ret = st->ops->read_adc(st, chan->channel, &read_val);
@@ -419,7 +417,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
 		} else {
 			int mult;
 
-			mutex_lock(&iio_dev->mlock);
+			mutex_lock(&st->lock);
 
 			if (chan->output)
 				mult = !!(st->cached_gp_ctrl &
@@ -437,7 +435,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
 	case IIO_CHAN_INFO_OFFSET:
 		ret = ad5592r_get_vref(st);
 
-		mutex_lock(&iio_dev->mlock);
+		mutex_lock(&st->lock);
 
 		if (st->cached_gp_ctrl & AD5592R_REG_CTRL_ADC_RANGE)
 			*val = (-34365 * 25) / ret;
@@ -450,7 +448,7 @@ static int ad5592r_read_raw(struct iio_dev *iio_dev,
 	}
 
 unlock:
-	mutex_unlock(&iio_dev->mlock);
+	mutex_unlock(&st->lock);
 	return ret;
 }
 
@@ -625,6 +623,8 @@ int ad5592r_probe(struct device *dev, const char *name,
 	iio_dev->info = &ad5592r_info;
 	iio_dev->modes = INDIO_DIRECT_MODE;
 
+	mutex_init(&st->lock);
+
 	ad5592r_init_scales(st, ad5592r_get_vref(st));
 
 	ret = ad5592r_reset(st);
diff --git a/drivers/iio/dac/ad5592r-base.h b/drivers/iio/dac/ad5592r-base.h
index 4774e4cd9c11..23dac2f1ff8a 100644
--- a/drivers/iio/dac/ad5592r-base.h
+++ b/drivers/iio/dac/ad5592r-base.h
@@ -52,6 +52,7 @@ struct ad5592r_state {
 	struct regulator *reg;
 	struct gpio_chip gpiochip;
 	struct mutex gpio_lock;	/* Protect cached gpio_out, gpio_val, etc. */
+	struct mutex lock;
 	unsigned int num_channels;
 	const struct ad5592r_rw_ops *ops;
 	int scale_avail[2][2];
-- 
2.17.1