iio: ad2s1200: Driver clean up

Remove unneeded newline in license, as it does not improve readability.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Introduced in this version.

 drivers/staging/iio/resolver/ad2s1200.c | 1 -
 1 file changed, 1 deletion(-)

drivers/staging/iio/resolver/ad2s1200.c +0 -1

index ea7336645116..df3b34200a89 100644
@@ -7,7 +7,6 @@
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
- *
  */
 
 #include <linux/bitops.h>

Remove 2 initializations which are unneeded, because the initialized values are never used.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Introduced in this version.

 drivers/staging/iio/resolver/ad2s1200.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

drivers/staging/iio/resolver/ad2s1200.c +2 -2

index df3b34200a89..9bdcf0c86217 100644
@@ -47,7 +47,7 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
 			     long m)
 {
 	struct ad2s1200_state *st = iio_priv(indio_dev);
-	int ret = 0;
+	int ret;
 
 	mutex_lock(&st->lock);
 	gpio_set_value(st->sample, 0);

@@ -105,7 +105,7 @@ static int ad2s1200_probe(struct spi_device *spi)
 	unsigned short *pins = spi->dev.platform_data;
 	struct ad2s1200_state *st;
 	struct iio_dev *indio_dev;
-	int pn, ret = 0;
+	int pn, ret;
 
 	for (pn = 0; pn < AD2S1200_PN; pn++) {
 		ret = devm_gpio_request_one(&spi->dev, pins[pn], GPIOF_DIR_OUT,

Add missing kernel docs to the ad2s1200 driver state.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Simplified explanation of lock.

 drivers/staging/iio/resolver/ad2s1200.c | 8 ++++++++
 1 file changed, 8 insertions(+)

drivers/staging/iio/resolver/ad2s1200.c +8 -0

index 9bdcf0c86217..068aa86e9c11 100644
@@ -32,6 +32,14 @@
 /* clock period in nano second */
 #define AD2S1200_TSCLK	(1000000000 / AD2S1200_HZ)
 
+/**
+ * struct ad2s1200_state - driver instance specific data.
+ * @lock:	protects both the GPIO pins and the rx buffer.
+ * @sdev:	spi device.
+ * @sample:	GPIO pin SAMPLE.
+ * @rdvel:	GPIO pin RDVEL.
+ * @rx:		buffer for spi transfers.
+ */
 struct ad2s1200_state {
 	struct mutex lock;
 	struct spi_device *sdev;

The spi should be set up before the device is registered as an iio device.

This patch moves the setup to before the device registration.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Introduced in this version.

 drivers/staging/iio/resolver/ad2s1200.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

drivers/staging/iio/resolver/ad2s1200.c +7 -6

index 068aa86e9c11..430cc62591fe 100644
@@ -143,15 +143,16 @@ static int ad2s1200_probe(struct spi_device *spi)
 	indio_dev->num_channels = ARRAY_SIZE(ad2s1200_channels);
 	indio_dev->name = spi_get_device_id(spi)->name;
 
-	ret = devm_iio_device_register(&spi->dev, indio_dev);
-	if (ret)
-		return ret;
-
 	spi->max_speed_hz = AD2S1200_HZ;
 	spi->mode = SPI_MODE_3;
-	spi_setup(spi);
+	ret = spi_setup(spi);
+
+	if (ret < 0) {
+		dev_err(&spi->dev, "spi_setup failed!\n");
+		return ret;
+	}
 
-	return 0;
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct spi_device_id ad2s1200_id[] = {

The legacy, integer based gpio API is replaced with the modern descriptor based API.

Signed-off-by David Veenstra <[email protected]>

---
 drivers/staging/iio/resolver/ad2s1200.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

drivers/staging/iio/resolver/ad2s1200.c +8 -7

index 430cc62591fe..b2c46a8c6b77 100644
@@ -13,6 +13,7 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/spi/spi.h>

@@ -43,8 +44,8 @@
 struct ad2s1200_state {
 	struct mutex lock;
 	struct spi_device *sdev;
-	int sample;
-	int rdvel;
+	struct gpio_desc *sample;
+	struct gpio_desc *rdvel;
 	__be16 rx ____cacheline_aligned;
 };
 

@@ -58,12 +59,12 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
 	int ret;
 
 	mutex_lock(&st->lock);
-	gpio_set_value(st->sample, 0);
+	gpiod_set_value(st->sample, 0);
 
 	/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
 	udelay(1);
-	gpio_set_value(st->sample, 1);
-	gpio_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
+	gpiod_set_value(st->sample, 1);
+	gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
 
 	ret = spi_read(st->sdev, &st->rx, 2);
 	if (ret < 0) {

@@ -133,8 +134,8 @@ static int ad2s1200_probe(struct spi_device *spi)
 	st = iio_priv(indio_dev);
 	mutex_init(&st->lock);
 	st->sdev = spi;
-	st->sample = pins[0];
-	st->rdvel = pins[1];
+	st->sample = gpio_to_desc(pins[0]);
+	st->rdvel = gpio_to_desc(pins[1]);
 
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->info = &ad2s1200_info;

Remove usage of platform data, and replace it with device tree facilities.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Added vendor prefix to gpio function names.

 drivers/staging/iio/resolver/ad2s1200.c | 32 ++++++++++++-------------
 1 file changed, 15 insertions(+), 17 deletions(-)

drivers/staging/iio/resolver/ad2s1200.c +15 -17

index b2c46a8c6b77..9a8aa2448897 100644
@@ -25,9 +25,6 @@
 
 #define DRV_NAME "ad2s1200"
 
-/* input pin sample and rdvel is controlled by driver */
-#define AD2S1200_PN	2
-
 /* input clock on serial interface */
 #define AD2S1200_HZ	8192000
 /* clock period in nano second */

@@ -111,20 +108,9 @@ static const struct iio_info ad2s1200_info = {
 
 static int ad2s1200_probe(struct spi_device *spi)
 {
-	unsigned short *pins = spi->dev.platform_data;
 	struct ad2s1200_state *st;
 	struct iio_dev *indio_dev;
-	int pn, ret;
-
-	for (pn = 0; pn < AD2S1200_PN; pn++) {
-		ret = devm_gpio_request_one(&spi->dev, pins[pn], GPIOF_DIR_OUT,
-					    DRV_NAME);
-		if (ret) {
-			dev_err(&spi->dev, "request gpio pin %d failed\n",
-				pins[pn]);
-			return ret;
-		}
-	}
+	int ret;
 
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)

@@ -134,8 +120,20 @@ static int ad2s1200_probe(struct spi_device *spi)
 	st = iio_priv(indio_dev);
 	mutex_init(&st->lock);
 	st->sdev = spi;
-	st->sample = gpio_to_desc(pins[0]);
-	st->rdvel = gpio_to_desc(pins[1]);
+
+	st->sample = devm_gpiod_get(&spi->dev, "adi,sample", GPIOD_OUT_LOW);
+	if (IS_ERR(st->sample)) {
+		dev_err(&spi->dev, "Failed to claim SAMPLE gpio: err=%ld\n",
+			PTR_ERR(st->sample));
+		return PTR_ERR(st->sample);
+	}
+
+	st->rdvel = devm_gpiod_get(&spi->dev, "adi,rdvel", GPIOD_OUT_LOW);
+	if (IS_ERR(st->rdvel)) {
+		dev_err(&spi->dev, "Failed to claim RDVEL gpio: err=%ld\n",
+			PTR_ERR(st->rdvel));
+		return PTR_ERR(st->rdvel);
+	}
 
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->info = &ad2s1200_info;

Add device tree table for matching with the vendor ID.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Introduced in this version.

 drivers/staging/iio/resolver/ad2s1200.c | 8 ++++++++
 1 file changed, 8 insertions(+)

drivers/staging/iio/resolver/ad2s1200.c +8 -0

index 9a8aa2448897..67d9747f88a6 100644
@@ -154,6 +154,13 @@ static int ad2s1200_probe(struct spi_device *spi)
 	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
+static const struct of_device_id ad2s1200_of_match[] = {
+	{ .compatible = "adi,ad2s1200", },
+	{ .compatible = "adi,ad2s1205", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ad2s1200_of_match);
+
 static const struct spi_device_id ad2s1200_id[] = {
 	{ "ad2s1200" },
 	{ "ad2s1205" },

@@ -164,6 +171,7 @@ MODULE_DEVICE_TABLE(spi, ad2s1200_id);
 static struct spi_driver ad2s1200_driver = {
 	.driver = {
 		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(ad2s1200_of_match),
 	},
 	.probe = ad2s1200_probe,
 	.id_table = ad2s1200_id,

Add documentation for the device tree bindings of the AD2S1200 resolver.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Added vendor prefix to gpio function name.
- Added unit address.
- Changed commit subject to be more inline with other dt-bindings commit .

 .../bindings/iio/resolver/ad2s1200.txt           | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt

Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt new file +0 -0

new file mode 100644
index 000000000000..bbf54260c911

Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt new file +5 -0

+		compatible = "adi,ad2s1200";
+		reg = <4>;
+		adi,sample-gpios = <&gpio 5 GPIO_ACTIVE_HIGH>;
+		adi,rdvel-gpios = <&gpio 6 GPIO_ACTIVE_HIGH>;
+	};

The sysfs iio ABI states radians per second is expected as the unit for angular velocity, but the 12-bit angular velocity register has revolution per seconds as its unit. So a scaling factor of approximately 2 * Pi is added to the angular velocity channel.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Changed rps to revolutions per second in commit message to prevent confusion.

 drivers/staging/iio/resolver/ad2s1200.c | 71 ++++++++++++++++---------
 1 file changed, 45 insertions(+), 26 deletions(-)

drivers/staging/iio/resolver/ad2s1200.c +45 -26

index 67d9747f88a6..7b8af558e921 100644
@@ -55,37 +55,55 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
 	struct ad2s1200_state *st = iio_priv(indio_dev);
 	int ret;
 
-	mutex_lock(&st->lock);
-	gpiod_set_value(st->sample, 0);
-
-	/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
-	udelay(1);
-	gpiod_set_value(st->sample, 1);
-	gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
-
-	ret = spi_read(st->sdev, &st->rx, 2);
-	if (ret < 0) {
+	switch (m) {
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			/* 2 * Pi ~= 6.283185 */
+			*val = 6;
+			*val2 = 283185;
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&st->lock);
+		gpiod_set_value(st->sample, 0);
+
+		/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
+		udelay(1);
+		gpiod_set_value(st->sample, 1);
+		gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
+
+		ret = spi_read(st->sdev, &st->rx, 2);
+		if (ret < 0) {
+			mutex_unlock(&st->lock);
+			return ret;
+		}
+
+		switch (chan->type) {
+		case IIO_ANGL:
+			*val = be16_to_cpup(&st->rx) >> 4;
+			break;
+		case IIO_ANGL_VEL:
+			*val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
+			break;
+		default:
+			mutex_unlock(&st->lock);
+			return -EINVAL;
+		}
+
+		/* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */
+		udelay(1);
 		mutex_unlock(&st->lock);
-		return ret;
-	}
 
-	switch (chan->type) {
-	case IIO_ANGL:
-		*val = be16_to_cpup(&st->rx) >> 4;
-		break;
-	case IIO_ANGL_VEL:
-		*val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
-		break;
+		return IIO_VAL_INT;
 	default:
-		mutex_unlock(&st->lock);
-		return -EINVAL;
+		break;
 	}
 
-	/* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */
-	udelay(1);
-	mutex_unlock(&st->lock);
-
-	return IIO_VAL_INT;
+	return -EINVAL;
 }
 
 static const struct iio_chan_spec ad2s1200_channels[] = {

@@ -99,6 +117,7 @@ static const struct iio_chan_spec ad2s1200_channels[] = {
 		.indexed = 1,
 		.channel = 0,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 	}
 };
 

A scaling factor of approximately 2 * Pi / (2^12 -1) is added, to scale the 12-bits angular position to radians.

A return type of IIO_VAL_INT_PLUS_NANO is used, so that the scale of both the angle channel and angular velocity channel has 7 significant digits.

Signed-off-by David Veenstra <[email protected]>

---
 drivers/staging/iio/resolver/ad2s1200.c | 6 ++++++
 1 file changed, 6 insertions(+)

drivers/staging/iio/resolver/ad2s1200.c +6 -0

index 7b8af558e921..10d6d79dce79 100644
@@ -58,6 +58,11 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
 	switch (m) {
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->type) {
+		case IIO_ANGL:
+			/* 2 * Pi / (2^12 - 1) ~= 0.001534355 */
+			*val = 0;
+			*val2 = 1534355;
+			return IIO_VAL_INT_PLUS_NANO;
 		case IIO_ANGL_VEL:
 			/* 2 * Pi ~= 6.283185 */
 			*val = 6;

@@ -112,6 +117,7 @@ static const struct iio_chan_spec ad2s1200_channels[] = {
 		.indexed = 1,
 		.channel = 0,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
 	}, {
 		.type = IIO_ANGL_VEL,
 		.indexed = 1,

Add David Veenstra as a copyright holders and as an author, for all of the staging clean ups of the ad2s1200 driver.

Signed-off-by David Veenstra <[email protected]>

---
Changes in v4:
- Introduced in this version.

 drivers/staging/iio/resolver/ad2s1200.c | 2 ++
 1 file changed, 2 insertions(+)

drivers/staging/iio/resolver/ad2s1200.c +2 -0

index 10d6d79dce79..28e618af9939 100644
@@ -2,6 +2,7 @@
  * ad2s1200.c simple support for the ADI Resolver to Digital Converters:
  * AD2S1200/1205
  *
+ * Copyright (c) 2018-2018 David Veenstra <[email protected]>
  * Copyright (c) 2010-2010 Analog Devices Inc.
  *
  * This program is free software; you can redistribute it and/or modify

@@ -203,6 +204,7 @@ static struct spi_driver ad2s1200_driver = {
 };
 module_spi_driver(ad2s1200_driver);
 
+MODULE_AUTHOR("David Veenstra <[email protected]>");
 MODULE_AUTHOR("Graff Yang <[email protected]>");
 MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver");
 MODULE_LICENSE("GPL v2");

Move the iio driver for the ad2s1200 and ad2s1205 resolver-to-digital converter out of staging, into mainline iio subsystems.

Signed-off-by David Veenstra <[email protected]>

---
 drivers/iio/Kconfig                     |   1 +
 drivers/iio/Makefile                    |   1 +
 drivers/iio/resolver/Kconfig            |  17 ++
 drivers/iio/resolver/Makefile           |   5 +
 drivers/iio/resolver/ad2s1200.c         | 210 ++++++++++++++++++++++++
 drivers/staging/iio/resolver/Kconfig    |  12 --
 drivers/staging/iio/resolver/Makefile   |   1 -
 drivers/staging/iio/resolver/ad2s1200.c | 210 ------------------------
 8 files changed, 234 insertions(+), 223 deletions(-)
 create mode 100644 drivers/iio/resolver/Kconfig
 create mode 100644 drivers/iio/resolver/Makefile
 create mode 100644 drivers/iio/resolver/ad2s1200.c
 delete mode 100644 drivers/staging/iio/resolver/ad2s1200.c

drivers/iio/Kconfig +1 -0

index d69e85a8bdc3..d08aeb41cd07 100644
@@ -93,6 +93,7 @@ source "drivers/iio/potentiometer/Kconfig"
 source "drivers/iio/potentiostat/Kconfig"
 source "drivers/iio/pressure/Kconfig"
 source "drivers/iio/proximity/Kconfig"
+source "drivers/iio/resolver/Kconfig"
 source "drivers/iio/temperature/Kconfig"
 
 endif # IIO

drivers/iio/Makefile +1 -0

index d8cba9c229c0..cb5993251381 100644
@@ -36,5 +36,6 @@ obj-y += potentiometer/
 obj-y += potentiostat/
 obj-y += pressure/
 obj-y += proximity/
+obj-y += resolver/
 obj-y += temperature/
 obj-y += trigger/

drivers/iio/resolver/Kconfig new file +17 -0

new file mode 100644
index 000000000000..2ced9f22aa70
@@ -0,0 +1,17 @@
+#
+# Resolver/Synchro drivers
+#
+menu "Resolver to digital converters"
+
+config AD2S1200
+	tristate "Analog Devices ad2s1200/ad2s1205 driver"
+	depends on SPI
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  Say yes here to build support for Analog Devices spi resolver
+	  to digital converters, ad2s1200 and ad2s1205, provides direct access
+	  via sysfs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad2s1200.
+endmenu

drivers/iio/resolver/Makefile new file +5 -0

new file mode 100644
index 000000000000..4e1dccae07e7
@@ -0,0 +1,5 @@
+#
+# Makefile for Resolver/Synchro drivers
+#
+
+obj-$(CONFIG_AD2S1200) += ad2s1200.o

drivers/iio/resolver/ad2s1200.c new file +17 -0

new file mode 100644
index 000000000000..28e618af9939
@@ -0,0 +1,210 @@
+/*
+ * ad2s1200.c simple support for the ADI Resolver to Digital Converters:
+ * AD2S1200/1205
+ *
+ * Copyright (c) 2018-2018 David Veenstra <[email protected]>
+ * Copyright (c) 2010-2010 Analog Devices Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>

drivers/iio/resolver/ad2s1200.c new file +75 -0

+
+/* input clock on serial interface */
+#define AD2S1200_HZ	8192000
+/* clock period in nano second */
+#define AD2S1200_TSCLK	(1000000000 / AD2S1200_HZ)
+
+/**
+ * struct ad2s1200_state - driver instance specific data.
+ * @lock:	protects both the GPIO pins and the rx buffer.
+ * @sdev:	spi device.
+ * @sample:	GPIO pin SAMPLE.
+ * @rdvel:	GPIO pin RDVEL.
+ * @rx:		buffer for spi transfers.
+ */
+struct ad2s1200_state {
+	struct mutex lock;
+	struct spi_device *sdev;
+	struct gpio_desc *sample;
+	struct gpio_desc *rdvel;
+	__be16 rx ____cacheline_aligned;
+};
+
+static int ad2s1200_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val,
+			     int *val2,
+			     long m)
+{
+	struct ad2s1200_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (m) {
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL:
+			/* 2 * Pi / (2^12 - 1) ~= 0.001534355 */
+			*val = 0;
+			*val2 = 1534355;
+			return IIO_VAL_INT_PLUS_NANO;
+		case IIO_ANGL_VEL:
+			/* 2 * Pi ~= 6.283185 */
+			*val = 6;
+			*val2 = 283185;
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&st->lock);
+		gpiod_set_value(st->sample, 0);
+
+		/* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
+		udelay(1);
+		gpiod_set_value(st->sample, 1);
+		gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
+
+		ret = spi_read(st->sdev, &st->rx, 2);
+		if (ret < 0) {
+			mutex_unlock(&st->lock);
+			return ret;
+		}
+
+		switch (chan->type) {
+		case IIO_ANGL:
+			*val = be16_to_cpup(&st->rx) >> 4;
+			break;
+		case IIO_ANGL_VEL:
+			*val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
+			break;
+		default:
+			mutex_unlock(&st->lock);
+			return -EINVAL;
+		}
+

drivers/iio/resolver/ad2s1200.c new file +98 -0

+}
+
+static const struct iio_chan_spec ad2s1200_channels[] = {
+	{
+		.type = IIO_ANGL,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+	}, {
+		.type = IIO_ANGL_VEL,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+	}
+};
+
+static const struct iio_info ad2s1200_info = {
+	.read_raw = ad2s1200_read_raw,
+};
+
+static int ad2s1200_probe(struct spi_device *spi)
+{
+	struct ad2s1200_state *st;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, indio_dev);
+	st = iio_priv(indio_dev);
+	mutex_init(&st->lock);
+	st->sdev = spi;
+
+	st->sample = devm_gpiod_get(&spi->dev, "adi,sample", GPIOD_OUT_LOW);
+	if (IS_ERR(st->sample)) {
+		dev_err(&spi->dev, "Failed to claim SAMPLE gpio: err=%ld\n",
+			PTR_ERR(st->sample));
+		return PTR_ERR(st->sample);
+	}
+
+	st->rdvel = devm_gpiod_get(&spi->dev, "adi,rdvel", GPIOD_OUT_LOW);
+	if (IS_ERR(st->rdvel)) {
+		dev_err(&spi->dev, "Failed to claim RDVEL gpio: err=%ld\n",
+			PTR_ERR(st->rdvel));
+		return PTR_ERR(st->rdvel);
+	}
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->info = &ad2s1200_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ad2s1200_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ad2s1200_channels);
+	indio_dev->name = spi_get_device_id(spi)->name;
+
+	spi->max_speed_hz = AD2S1200_HZ;
+	spi->mode = SPI_MODE_3;
+	ret = spi_setup(spi);
+
+	if (ret < 0) {
+		dev_err(&spi->dev, "spi_setup failed!\n");
+		return ret;
+	}
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id ad2s1200_of_match[] = {
+	{ .compatible = "adi,ad2s1200", },
+	{ .compatible = "adi,ad2s1205", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ad2s1200_of_match);
+
+static const struct spi_device_id ad2s1200_id[] = {
+	{ "ad2s1200" },
+	{ "ad2s1205" },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad2s1200_id);
+
+static struct spi_driver ad2s1200_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(ad2s1200_of_match),
+	},
+	.probe = ad2s1200_probe,
+	.id_table = ad2s1200_id,
+};
+module_spi_driver(ad2s1200_driver);
+
+MODULE_AUTHOR("David Veenstra <[email protected]>");
+MODULE_AUTHOR("Graff Yang <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver");
+MODULE_LICENSE("GPL v2");