1 files changed, 28 insertions, 19 deletions

diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index 113703fb7245..5a863005aca6 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -142,7 +142,7 @@ static const struct iio_chan_spec ad7768_channels[] = {
 		.channel = 0,
 		.scan_index = 0,
 		.scan_type = {
-			.sign = 'u',
+			.sign = 's',
 			.realbits = 24,
 			.storagebits = 32,
 			.shift = 8,
@@ -154,7 +154,6 @@ static const struct iio_chan_spec ad7768_channels[] = {
 struct ad7768_state {
 	struct spi_device *spi;
 	struct regulator *vref;
-	struct mutex lock;
 	struct clk *mclk;
 	unsigned int mclk_freq;
 	unsigned int samp_freq;
@@ -256,18 +255,20 @@ static int ad7768_reg_access(struct iio_dev *indio_dev,
 	struct ad7768_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&st->lock);
+	if (!iio_device_claim_direct(indio_dev))
+		return -EBUSY;
+
 	if (readval) {
 		ret = ad7768_spi_reg_read(st, reg, 1);
 		if (ret < 0)
-			goto err_unlock;
+			goto err_release;
 		*readval = ret;
 		ret = 0;
 	} else {
 		ret = ad7768_spi_reg_write(st, reg, writeval);
 	}
-err_unlock:
-	mutex_unlock(&st->lock);
+err_release:
+	iio_device_release_direct(indio_dev);
 
 	return ret;
 }
@@ -365,17 +366,15 @@ static int ad7768_read_raw(struct iio_dev *indio_dev,
 
 	switch (info) {
 	case IIO_CHAN_INFO_RAW:
-		ret = iio_device_claim_direct_mode(indio_dev);
-		if (ret)
-			return ret;
+		if (!iio_device_claim_direct(indio_dev))
+			return -EBUSY;
 
 		ret = ad7768_scan_direct(indio_dev);
-		if (ret >= 0)
-			*val = ret;
 
-		iio_device_release_direct_mode(indio_dev);
+		iio_device_release_direct(indio_dev);
 		if (ret < 0)
 			return ret;
+		*val = sign_extend32(ret, chan->scan_type.realbits - 1);
 
 		return IIO_VAL_INT;
 
@@ -471,18 +470,15 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p)
 	struct ad7768_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&st->lock);
-
 	ret = spi_read(st->spi, &st->data.scan.chan, 3);
 	if (ret < 0)
-		goto err_unlock;
+		goto out;
 
 	iio_push_to_buffers_with_timestamp(indio_dev, &st->data.scan,
 					   iio_get_time_ns(indio_dev));
 
-err_unlock:
+out:
 	iio_trigger_notify_done(indio_dev->trig);
-	mutex_unlock(&st->lock);
 
 	return IRQ_HANDLED;
 }
@@ -574,6 +570,21 @@ static int ad7768_probe(struct spi_device *spi)
 		return -ENOMEM;
 
 	st = iio_priv(indio_dev);
+	/*
+	 * Datasheet recommends SDI line to be kept high when data is not being
+	 * clocked out of the controller and the spi clock is free running,
+	 * to prevent accidental reset.
+	 * Since many controllers do not support the SPI_MOSI_IDLE_HIGH flag
+	 * yet, only request the MOSI idle state to enable if the controller
+	 * supports it.
+	 */
+	if (spi->controller->mode_bits & SPI_MOSI_IDLE_HIGH) {
+		spi->mode |= SPI_MOSI_IDLE_HIGH;
+		ret = spi_setup(spi);
+		if (ret < 0)
+			return ret;
+	}
+
 	st->spi = spi;
 
 	st->vref = devm_regulator_get(&spi->dev, "vref");
@@ -596,8 +607,6 @@ static int ad7768_probe(struct spi_device *spi)
 
 	st->mclk_freq = clk_get_rate(st->mclk);
 
-	mutex_init(&st->lock);
-
 	indio_dev->channels = ad7768_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);
 	indio_dev->name = spi_get_device_id(spi)->name;