iio: dac: ad5504: bindings, cleanups, locking, and scale fixes

index ad1a74678cf2..5c9c66b04154 100644
@@ -5,22 +5,25 @@
  * Copyright 2011 Analog Devices Inc.
  */
 
-#include <linux/bitops.h>
-#include <linux/device.h>
-#include <linux/fs.h>
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/errno.h>
 #include <linux/interrupt.h>
-#include <linux/kernel.h>
+#include <linux/kstrtox.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
-#include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/sysfs.h>
+#include <linux/types.h>
 
 #include <linux/iio/dac/ad5504.h>
 #include <linux/iio/events.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
+#include <asm/byteorder.h>
+
 #define AD5504_RES_MASK			GENMASK(11, 0)
 #define AD5504_CMD_READ			BIT(15)
 #define AD5504_CMD_WRITE		0

index 5c9c66b04154..6f70c57c7a82 100644
@@ -5,6 +5,7 @@
  * Copyright 2011 Analog Devices Inc.
  */
 
+#include <linux/acpi.h>
 #include <linux/array_size.h>
 #include <linux/bits.h>
 #include <linux/dev_printk.h>

@@ -12,10 +13,12 @@
 #include <linux/interrupt.h>
 #include <linux/kstrtox.h>
 #include <linux/module.h>
+#include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>
 #include <linux/sysfs.h>
 #include <linux/types.h>
+#include <linux/units.h>
 
 #include <linux/iio/dac/ad5504.h>
 #include <linux/iio/events.h>

@@ -24,6 +27,10 @@
 
 #include <asm/byteorder.h>
 
+/*
+ * In case of ACPI, we use the 60 V as default voltage reference.
+ */
+#define AD5504_VREF_ACPI_DEFAULT_mV	(60 * MILLI)
 #define AD5504_RES_MASK			GENMASK(11, 0)
 #define AD5504_CMD_READ			BIT(15)
 #define AD5504_CMD_WRITE		0

@@ -285,16 +292,20 @@ static int ad5504_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
-	ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
-	if (ret < 0 && ret != -ENODEV)
-		return ret;
-	if (ret == -ENODEV) {
-		if (pdata->vref_mv)
-			st->vref_mv = pdata->vref_mv;
-		else
-			dev_warn(dev, "reference voltage unspecified\n");
+	if (is_acpi_device_node(dev_fwnode(dev))) {
+		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
-		st->vref_mv = ret / 1000;
+		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
+		if (ret < 0 && ret != -ENODEV)
+			return ret;
+		if (ret == -ENODEV) {
+			if (pdata->vref_mv)
+				st->vref_mv = pdata->vref_mv;
+			else
+				dev_warn(dev, "reference voltage unspecified\n");
+		} else {
+			st->vref_mv = ret / 1000;
+		}
 	}
 
 	st->spi = spi;

index 6f70c57c7a82..799726eafdf2 100644
@@ -20,7 +20,6 @@
 #include <linux/types.h>
 #include <linux/units.h>
 
-#include <linux/iio/dac/ad5504.h>
 #include <linux/iio/events.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>

@@ -281,7 +280,6 @@ static const struct iio_chan_spec ad5504_channels[] = {
 static int ad5504_probe(struct spi_device *spi)
 {
 	struct device *dev = &spi->dev;
-	const struct ad5504_platform_data *pdata = dev_get_platdata(dev);
 	struct iio_dev *indio_dev;
 	struct ad5504_state *st;
 	int ret;

@@ -296,16 +294,11 @@ static int ad5504_probe(struct spi_device *spi)
 		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
 		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
-		if (ret < 0 && ret != -ENODEV)
-			return ret;
-		if (ret == -ENODEV) {
-			if (pdata->vref_mv)
-				st->vref_mv = pdata->vref_mv;
-			else
-				dev_warn(dev, "reference voltage unspecified\n");
-		} else {
-			st->vref_mv = ret / 1000;
-		}
+		if (ret < 0)
+			return dev_err_probe(dev, ret,
+					     "Failed to get vcc regulator\n");
+
+		st->vref_mv = ret / 1000;
 	}
 
 	st->spi = spi;

deleted file mode 100644
index 9f23c90486ee..000000000000
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * AD5504 SPI DAC driver
- *
- * Copyright 2011 Analog Devices Inc.
- */
-
-#ifndef SPI_AD5504_H_
-#define SPI_AD5504_H_
-
-struct ad5504_platform_data {
-	u16				vref_mv;
-};
-
-#endif /* SPI_AD5504_H_ */

index 799726eafdf2..74679feea385 100644
@@ -8,11 +8,13 @@
 #include <linux/acpi.h>
 #include <linux/array_size.h>
 #include <linux/bits.h>
+#include <linux/cleanup.h>
 #include <linux/dev_printk.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/kstrtox.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>

@@ -55,10 +57,12 @@
  * @pwr_down_mask:	power down mask
  * @pwr_down_mode:	current power down mode
  * @data:		transfer buffer
+ * @lock:		lock to protect state and spi transfers
  */
 struct ad5504_state {
 	struct spi_device		*spi;
 	struct regulator		*reg;
+	struct mutex			lock;
 	unsigned short			vref_mv;
 	unsigned			pwr_down_mask;
 	unsigned			pwr_down_mode;

@@ -109,7 +113,9 @@ static int ad5504_read_raw(struct iio_dev *indio_dev,
 	int ret;
 
 	switch (m) {
-	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_RAW: {
+		guard(mutex)(&st->lock);
+
 		ret = ad5504_spi_read(st, chan->address);
 		if (ret < 0)
 			return ret;

@@ -117,6 +123,7 @@ static int ad5504_read_raw(struct iio_dev *indio_dev,
 		*val = ret;
 
 		return IIO_VAL_INT;
+	}
 	case IIO_CHAN_INFO_SCALE:
 		*val = st->vref_mv;
 		*val2 = chan->scan_type.realbits;

@@ -134,11 +141,14 @@ static int ad5504_write_raw(struct iio_dev *indio_dev,
 	struct ad5504_state *st = iio_priv(indio_dev);
 
 	switch (mask) {
-	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_RAW: {
+		guard(mutex)(&st->lock);
+
 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
 			return -EINVAL;
 
 		return ad5504_spi_write(st, chan->address, val);
+	}
 	default:
 		return -EINVAL;
 	}

@@ -154,6 +164,8 @@ static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 
+	guard(mutex)(&st->lock);
+
 	return st->pwr_down_mode;
 }
 

@@ -162,6 +174,8 @@ static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 
+	guard(mutex)(&st->lock);
+
 	st->pwr_down_mode = mode;
 
 	return 0;

@@ -179,6 +193,8 @@ static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
 {
 	struct ad5504_state *st = iio_priv(indio_dev);
 
+	guard(mutex)(&st->lock);
+
 	return sysfs_emit(buf, "%d\n",
 			  !(st->pwr_down_mask & (1 << chan->channel)));
 }

@@ -195,6 +211,8 @@ static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
 	if (ret)
 		return ret;
 
+	guard(mutex)(&st->lock);
+
 	if (pwr_down)
 		st->pwr_down_mask &= ~(1 << chan->channel);
 	else

@@ -290,6 +308,10 @@ static int ad5504_probe(struct spi_device *spi)
 
 	st = iio_priv(indio_dev);
 
+	ret = devm_mutex_init(dev, &st->lock);
+	if (ret)
+		return ret;
+
 	if (is_acpi_device_node(dev_fwnode(dev))) {
 		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {

index 74679feea385..d0a3dd4b000d 100644
@@ -300,6 +300,7 @@ static int ad5504_probe(struct spi_device *spi)
 	struct device *dev = &spi->dev;
 	struct iio_dev *indio_dev;
 	struct ad5504_state *st;
+	u32 range[2];
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));

@@ -315,12 +316,30 @@ static int ad5504_probe(struct spi_device *spi)
 	if (is_acpi_device_node(dev_fwnode(dev))) {
 		st->vref_mv = AD5504_VREF_ACPI_DEFAULT_mV;
 	} else {
-		ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
-		if (ret < 0)
-			return dev_err_probe(dev, ret,
-					     "Failed to get vcc regulator\n");
-
-		st->vref_mv = ret / 1000;
+		if (device_property_present(dev, "output-range-microvolt")) {
+			ret = device_property_read_u32_array(dev, "output-range-microvolt",
+							     range, ARRAY_SIZE(range));
+			if (ret)
+				return dev_err_probe(dev, ret,
+							"Error parsing output-range-microvolt\n");
+
+			if (range[0] != 0 || (range[1] != 30 * MICRO && range[1] != 60 * MICRO))
+				return dev_err_probe(dev, -EINVAL,
+					"Invalid output-range-microvolt\n");
+
+			st->vref_mv = range[1] / (MICRO / MILLI);
+
+			ret = devm_regulator_get_enable(dev, "vcc");
+			if (ret < 0)
+				return dev_err_probe(dev, ret, "Failed to enable vcc regulator\n");
+		} else {
+			/* Backward compat: old DTs without output-range-microvolt */
+			ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
+			if (ret < 0)
+				return dev_err_probe(dev, ret, "Failed to get vcc regulator\n");
+
+			st->vref_mv = ret / (MICRO / MILLI);
+		}
 	}
 
 	st->spi = spi;