1 files changed, 319 insertions, 198 deletions

diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
index 97c1e5d780df..ae7297f08398 100644
--- a/drivers/iio/dac/ad5791.c
+++ b/drivers/iio/dac/ad5791.c
@@ -1,32 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog
  * Converter
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
-#include <linux/interrupt.h>
-#include <linux/fs.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
 #include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
 #include <linux/kernel.h>
-#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
+#include <linux/spi/offload/consumer.h>
+#include <linux/spi/spi.h>
 #include <linux/sysfs.h>
-#include <linux/regulator/consumer.h>
-#include <linux/module.h>
+#include <linux/units.h>
 
+#include <linux/iio/buffer-dmaengine.h>
+#include <linux/iio/dac/ad5791.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
-#include <linux/iio/dac/ad5791.h>
 
-#define AD5791_RES_MASK(x)		((1 << (x)) - 1)
-#define AD5791_DAC_MASK			AD5791_RES_MASK(20)
-#define AD5791_DAC_MSB			(1 << 19)
+#define AD5791_DAC_MASK			GENMASK(19, 0)
 
-#define AD5791_CMD_READ			(1 << 23)
-#define AD5791_CMD_WRITE		(0 << 23)
+#define AD5791_CMD_READ			BIT(23)
+#define AD5791_CMD_WRITE		0
 #define AD5791_ADDR(addr)		((addr) << 20)
 
 /* Registers */
@@ -37,11 +39,11 @@
 #define AD5791_ADDR_SW_CTRL		4
 
 /* Control Register */
-#define AD5791_CTRL_RBUF		(1 << 1)
-#define AD5791_CTRL_OPGND		(1 << 2)
-#define AD5791_CTRL_DACTRI		(1 << 3)
-#define AD5791_CTRL_BIN2SC		(1 << 4)
-#define AD5791_CTRL_SDODIS		(1 << 5)
+#define AD5791_CTRL_RBUF		BIT(1)
+#define AD5791_CTRL_OPGND		BIT(2)
+#define AD5791_CTRL_DACTRI		BIT(3)
+#define AD5791_CTRL_BIN2SC		BIT(4)
+#define AD5791_CTRL_SDODIS		BIT(5)
 #define AD5761_CTRL_LINCOMP(x)		((x) << 6)
 
 #define AD5791_LINCOMP_0_10		0
@@ -54,98 +56,100 @@
 #define AD5780_LINCOMP_10_20		12
 
 /* Software Control Register */
-#define AD5791_SWCTRL_LDAC		(1 << 0)
-#define AD5791_SWCTRL_CLR		(1 << 1)
-#define AD5791_SWCTRL_RESET		(1 << 2)
+#define AD5791_SWCTRL_LDAC		BIT(0)
+#define AD5791_SWCTRL_CLR		BIT(1)
+#define AD5791_SWCTRL_RESET		BIT(2)
 
 #define AD5791_DAC_PWRDN_6K		0
 #define AD5791_DAC_PWRDN_3STATE		1
 
 /**
  * struct ad5791_chip_info - chip specific information
+ * @name:		name of the dac chip
+ * @channel:		channel specification
+ * @channel_offload:	channel specification for offload
  * @get_lin_comp:	function pointer to the device specific function
  */
-
 struct ad5791_chip_info {
-	int (*get_lin_comp)	(unsigned int span);
+	const char *name;
+	const struct iio_chan_spec channel;
+	const struct iio_chan_spec channel_offload;
+	int (*get_lin_comp)(unsigned int span);
 };
 
 /**
  * struct ad5791_state - driver instance specific data
- * @us:			spi_device
- * @reg_vdd:		positive supply regulator
- * @reg_vss:		negative supply regulator
+ * @spi:			spi_device
+ * @gpio_reset:		reset gpio
+ * @gpio_clear:		clear gpio
+ * @gpio_ldac:		load dac gpio
  * @chip_info:		chip model specific constants
+ * @offload_msg:	spi message used for offload
+ * @offload_xfer:	spi transfer used for offload
+ * @offload:		offload device
+ * @offload_trigger:	offload trigger
+ * @offload_trigger_hz:	offload sample rate
  * @vref_mv:		actual reference voltage used
  * @vref_neg_mv:	voltage of the negative supply
- * @pwr_down_mode	current power down mode
+ * @ctrl:		control register cache
+ * @pwr_down_mode:	current power down mode
+ * @pwr_down:		true if device is powered down
+ * @data:		spi transfer buffers
  */
-
 struct ad5791_state {
 	struct spi_device		*spi;
-	struct regulator		*reg_vdd;
-	struct regulator		*reg_vss;
+	struct gpio_desc		*gpio_reset;
+	struct gpio_desc		*gpio_clear;
+	struct gpio_desc		*gpio_ldac;
 	const struct ad5791_chip_info	*chip_info;
+	struct spi_message		offload_msg;
+	struct spi_transfer		offload_xfer;
+	struct spi_offload		*offload;
+	struct spi_offload_trigger	*offload_trigger;
+	unsigned int			offload_trigger_hz;
 	unsigned short			vref_mv;
 	unsigned int			vref_neg_mv;
 	unsigned			ctrl;
 	unsigned			pwr_down_mode;
 	bool				pwr_down;
-};
-
-/**
- * ad5791_supported_device_ids:
- */
 
-enum ad5791_supported_device_ids {
-	ID_AD5760,
-	ID_AD5780,
-	ID_AD5781,
-	ID_AD5791,
-};
-
-static int ad5791_spi_write(struct spi_device *spi, u8 addr, u32 val)
-{
 	union {
-		u32 d32;
+		__be32 d32;
 		u8 d8[4];
-	} data;
+	} data[3] __aligned(IIO_DMA_MINALIGN);
+};
 
-	data.d32 = cpu_to_be32(AD5791_CMD_WRITE |
+static int ad5791_spi_write(struct ad5791_state *st, u8 addr, u32 val)
+{
+	st->data[0].d32 = cpu_to_be32(AD5791_CMD_WRITE |
 			      AD5791_ADDR(addr) |
 			      (val & AD5791_DAC_MASK));
 
-	return spi_write(spi, &data.d8[1], 3);
+	return spi_write(st->spi, &st->data[0].d8[1], 3);
 }
 
-static int ad5791_spi_read(struct spi_device *spi, u8 addr, u32 *val)
+static int ad5791_spi_read(struct ad5791_state *st, u8 addr, u32 *val)
 {
-	union {
-		u32 d32;
-		u8 d8[4];
-	} data[3];
 	int ret;
 	struct spi_transfer xfers[] = {
 		{
-			.tx_buf = &data[0].d8[1],
-			.bits_per_word = 8,
+			.tx_buf = &st->data[0].d8[1],
 			.len = 3,
 			.cs_change = 1,
 		}, {
-			.tx_buf = &data[1].d8[1],
-			.rx_buf = &data[2].d8[1],
-			.bits_per_word = 8,
+			.tx_buf = &st->data[1].d8[1],
+			.rx_buf = &st->data[2].d8[1],
 			.len = 3,
 		},
 	};
 
-	data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
+	st->data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
 			      AD5791_ADDR(addr));
-	data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
+	st->data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
 
-	ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
+	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
 
-	*val = be32_to_cpu(data[2].d32);
+	*val = be32_to_cpu(st->data[2].d32);
 
 	return ret;
 }
@@ -185,7 +189,7 @@ static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev,
 {
 	struct ad5791_state *st = iio_priv(indio_dev);
 
-	return sprintf(buf, "%d\n", st->pwr_down);
+	return sysfs_emit(buf, "%d\n", st->pwr_down);
 }
 
 static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
@@ -196,7 +200,7 @@ static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
 	int ret;
 	struct ad5791_state *st = iio_priv(indio_dev);
 
-	ret = strtobool(buf, &pwr_down);
+	ret = kstrtobool(buf, &pwr_down);
 	if (ret)
 		return ret;
 
@@ -210,7 +214,7 @@ static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev,
 	}
 	st->pwr_down = pwr_down;
 
-	ret = ad5791_spi_write(st->spi, AD5791_ADDR_CTRL, st->ctrl);
+	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl);
 
 	return ret ? ret : len;
 }
@@ -236,20 +240,25 @@ static int ad5780_get_lin_comp(unsigned int span)
 	else
 		return AD5780_LINCOMP_10_20;
 }
-static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
-	[ID_AD5760] = {
-		.get_lin_comp = ad5780_get_lin_comp,
-	},
-	[ID_AD5780] = {
-		.get_lin_comp = ad5780_get_lin_comp,
-	},
-	[ID_AD5781] = {
-		.get_lin_comp = ad5791_get_lin_comp,
-	},
-	[ID_AD5791] = {
-		.get_lin_comp = ad5791_get_lin_comp,
-	},
-};
+
+static int ad5791_set_sample_freq(struct ad5791_state *st, int val)
+{
+	struct spi_offload_trigger_config config = {
+		.type = SPI_OFFLOAD_TRIGGER_PERIODIC,
+		.periodic = {
+			.frequency_hz = val,
+		},
+	};
+	int ret;
+
+	ret = spi_offload_trigger_validate(st->offload_trigger, &config);
+	if (ret)
+		return ret;
+
+	st->offload_trigger_hz = config.periodic.frequency_hz;
+
+	return 0;
+}
 
 static int ad5791_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
@@ -263,21 +272,24 @@ static int ad5791_read_raw(struct iio_dev *indio_dev,
 
 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
-		ret = ad5791_spi_read(st->spi, chan->address, val);
+		ret = ad5791_spi_read(st, chan->address, val);
 		if (ret)
 			return ret;
 		*val &= AD5791_DAC_MASK;
 		*val >>= chan->scan_type.shift;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
-		*val = 0;
-		*val2 = (((u64)st->vref_mv) * 1000000ULL) >> chan->scan_type.realbits;
-		return IIO_VAL_INT_PLUS_MICRO;
+		*val = st->vref_mv;
+		*val2 = (1 << chan->scan_type.realbits) - 1;
+		return IIO_VAL_FRACTIONAL;
 	case IIO_CHAN_INFO_OFFSET:
 		val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits);
 		do_div(val64, st->vref_mv);
 		*val = -val64;
 		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = st->offload_trigger_hz;
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}
@@ -287,34 +299,62 @@ static int ad5791_read_raw(struct iio_dev *indio_dev,
 static const struct iio_chan_spec_ext_info ad5791_ext_info[] = {
 	{
 		.name = "powerdown",
-		.shared = true,
+		.shared = IIO_SHARED_BY_TYPE,
 		.read = ad5791_read_dac_powerdown,
 		.write = ad5791_write_dac_powerdown,
 	},
-	IIO_ENUM("powerdown_mode", true, &ad5791_powerdown_mode_enum),
-	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum),
-	{ },
+	IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
+		 &ad5791_powerdown_mode_enum),
+	IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5791_powerdown_mode_enum),
+	{ }
 };
 
-#define AD5791_CHAN(bits, shift) {			\
-	.type = IIO_VOLTAGE,				\
-	.output = 1,					\
-	.indexed = 1,					\
-	.address = AD5791_ADDR_DAC0,			\
-	.channel = 0,					\
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
-		BIT(IIO_CHAN_INFO_OFFSET),		\
-	.scan_type = IIO_ST('u', bits, 24, shift),	\
-	.ext_info = ad5791_ext_info,			\
+#define AD5791_DEFINE_CHIP_INFO(_name, bits, _shift, _lin_comp)		\
+static const struct ad5791_chip_info _name##_chip_info = {		\
+	.name = #_name,							\
+	.get_lin_comp = &(_lin_comp),					\
+	.channel = {							\
+			.type = IIO_VOLTAGE,				\
+			.output = 1,					\
+			.indexed = 1,					\
+			.address = AD5791_ADDR_DAC0,			\
+			.channel = 0,					\
+			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+			.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
+				BIT(IIO_CHAN_INFO_OFFSET),		\
+			.scan_type = {					\
+				.sign = 'u',				\
+				.realbits = (bits),			\
+				.storagebits = 32,			\
+				.shift = (_shift),			\
+			},						\
+			.ext_info = ad5791_ext_info,			\
+	},								\
+	.channel_offload = {						\
+			.type = IIO_VOLTAGE,				\
+			.output = 1,					\
+			.indexed = 1,					\
+			.address = AD5791_ADDR_DAC0,			\
+			.channel = 0,					\
+			.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+			.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
+				BIT(IIO_CHAN_INFO_OFFSET),		\
+			.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
+			.scan_type = {					\
+				.sign = 'u',				\
+				.realbits = (bits),			\
+				.storagebits = 32,			\
+				.shift = (_shift),			\
+			},						\
+			.ext_info = ad5791_ext_info,			\
+	},								\
 }
 
-static const struct iio_chan_spec ad5791_channels[] = {
-	[ID_AD5760] = AD5791_CHAN(16, 4),
-	[ID_AD5780] = AD5791_CHAN(18, 2),
-	[ID_AD5781] = AD5791_CHAN(18, 2),
-	[ID_AD5791] = AD5791_CHAN(20, 0)
-};
+AD5791_DEFINE_CHIP_INFO(ad5760, 16, 4, ad5780_get_lin_comp);
+AD5791_DEFINE_CHIP_INFO(ad5780, 18, 2, ad5780_get_lin_comp);
+AD5791_DEFINE_CHIP_INFO(ad5781, 18, 2, ad5791_get_lin_comp);
+AD5791_DEFINE_CHIP_INFO(ad5790, 20, 0, ad5791_get_lin_comp);
+AD5791_DEFINE_CHIP_INFO(ad5791, 20, 0, ad5791_get_lin_comp);
 
 static int ad5791_write_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
@@ -326,65 +366,161 @@ static int ad5791_write_raw(struct iio_dev *indio_dev,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
-		val &= AD5791_RES_MASK(chan->scan_type.realbits);
+		val &= GENMASK(chan->scan_type.realbits - 1, 0);
 		val <<= chan->scan_type.shift;
 
-		return ad5791_spi_write(st->spi, chan->address, val);
+		return ad5791_spi_write(st, chan->address, val);
 
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val < 1)
+			return -EINVAL;
+		return ad5791_set_sample_freq(st, val);
 	default:
 		return -EINVAL;
 	}
 }
 
+static int ad5791_write_raw_get_fmt(struct iio_dev *indio_dev,
+				    struct iio_chan_spec const *chan,
+				    long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return IIO_VAL_INT;
+	default:
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+}
+
+static int ad5791_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+	struct spi_offload_trigger_config config = {
+		.type = SPI_OFFLOAD_TRIGGER_PERIODIC,
+		.periodic = {
+			.frequency_hz = st->offload_trigger_hz,
+		},
+	};
+
+	if (st->pwr_down)
+		return -EINVAL;
+
+	return spi_offload_trigger_enable(st->offload, st->offload_trigger,
+					 &config);
+}
+
+static int ad5791_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+
+	spi_offload_trigger_disable(st->offload, st->offload_trigger);
+
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops ad5791_buffer_setup_ops = {
+	.preenable = &ad5791_buffer_preenable,
+	.postdisable = &ad5791_buffer_postdisable,
+};
+
+static int ad5791_offload_setup(struct iio_dev *indio_dev)
+{
+	struct ad5791_state *st = iio_priv(indio_dev);
+	struct spi_device *spi = st->spi;
+	struct dma_chan *tx_dma;
+	int ret;
+
+	st->offload_trigger = devm_spi_offload_trigger_get(&spi->dev,
+		st->offload, SPI_OFFLOAD_TRIGGER_PERIODIC);
+	if (IS_ERR(st->offload_trigger))
+		return dev_err_probe(&spi->dev, PTR_ERR(st->offload_trigger),
+				     "failed to get offload trigger\n");
+
+	ret = ad5791_set_sample_freq(st, 1 * MEGA);
+	if (ret)
+		return dev_err_probe(&spi->dev, ret,
+				     "failed to init sample rate\n");
+
+	tx_dma = devm_spi_offload_tx_stream_request_dma_chan(&spi->dev,
+							     st->offload);
+	if (IS_ERR(tx_dma))
+		return dev_err_probe(&spi->dev, PTR_ERR(tx_dma),
+				     "failed to get offload TX DMA\n");
+
+	ret = devm_iio_dmaengine_buffer_setup_with_handle(&spi->dev,
+		indio_dev, tx_dma, IIO_BUFFER_DIRECTION_OUT);
+	if (ret)
+		return ret;
+
+	st->offload_xfer.len = 4;
+	st->offload_xfer.bits_per_word = 24;
+	st->offload_xfer.offload_flags = SPI_OFFLOAD_XFER_TX_STREAM;
+
+	spi_message_init_with_transfers(&st->offload_msg, &st->offload_xfer, 1);
+	st->offload_msg.offload = st->offload;
+
+	return devm_spi_optimize_message(&spi->dev, st->spi, &st->offload_msg);
+}
+
 static const struct iio_info ad5791_info = {
 	.read_raw = &ad5791_read_raw,
 	.write_raw = &ad5791_write_raw,
-	.driver_module = THIS_MODULE,
+	.write_raw_get_fmt = &ad5791_write_raw_get_fmt,
+};
+
+static const struct spi_offload_config ad5791_offload_config = {
+	.capability_flags = SPI_OFFLOAD_CAP_TRIGGER |
+			    SPI_OFFLOAD_CAP_TX_STREAM_DMA,
 };
 
 static int ad5791_probe(struct spi_device *spi)
 {
-	struct ad5791_platform_data *pdata = spi->dev.platform_data;
+	const struct ad5791_platform_data *pdata = dev_get_platdata(&spi->dev);
 	struct iio_dev *indio_dev;
 	struct ad5791_state *st;
 	int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
+	bool use_rbuf_gain2;
 
-	indio_dev = iio_device_alloc(sizeof(*st));
-	if (indio_dev == NULL) {
-		ret = -ENOMEM;
-		goto error_ret;
-	}
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
 	st = iio_priv(indio_dev);
-	st->reg_vdd = regulator_get(&spi->dev, "vdd");
-	if (!IS_ERR(st->reg_vdd)) {
-		ret = regulator_enable(st->reg_vdd);
-		if (ret)
-			goto error_put_reg_pos;
-
-		ret = regulator_get_voltage(st->reg_vdd);
-		if (ret < 0)
-			goto error_disable_reg_pos;
-
-		pos_voltage_uv = ret;
-	}
 
-	st->reg_vss = regulator_get(&spi->dev, "vss");
-	if (!IS_ERR(st->reg_vss)) {
-		ret = regulator_enable(st->reg_vss);
-		if (ret)
-			goto error_put_reg_neg;
+	st->gpio_reset = devm_gpiod_get_optional(&spi->dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(st->gpio_reset))
+		return PTR_ERR(st->gpio_reset);
 
-		ret = regulator_get_voltage(st->reg_vss);
-		if (ret < 0)
-			goto error_disable_reg_neg;
+	st->gpio_clear = devm_gpiod_get_optional(&spi->dev, "clear",
+						 GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_clear))
+		return PTR_ERR(st->gpio_clear);
 
-		neg_voltage_uv = ret;
-	}
+	st->gpio_ldac = devm_gpiod_get_optional(&spi->dev, "ldac",
+						GPIOD_OUT_HIGH);
+	if (IS_ERR(st->gpio_ldac))
+		return PTR_ERR(st->gpio_ldac);
 
 	st->pwr_down = true;
 	st->spi = spi;
 
-	if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) {
+	if (pdata)
+		use_rbuf_gain2 = pdata->use_rbuf_gain2;
+	else
+		use_rbuf_gain2 = device_property_read_bool(&spi->dev,
+							   "adi,rbuf-gain2-en");
+
+	pos_voltage_uv = devm_regulator_get_enable_read_voltage(&spi->dev, "vdd");
+	if (pos_voltage_uv < 0 && pos_voltage_uv != -ENODEV)
+		return dev_err_probe(&spi->dev, pos_voltage_uv,
+				     "failed to get vdd voltage\n");
+
+	neg_voltage_uv = devm_regulator_get_enable_read_voltage(&spi->dev, "vss");
+	if (neg_voltage_uv < 0 && neg_voltage_uv != -ENODEV)
+		return dev_err_probe(&spi->dev, neg_voltage_uv,
+				     "failed to get vss voltage\n");
+
+	if (neg_voltage_uv >= 0 && pos_voltage_uv >= 0) {
 		st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000;
 		st->vref_neg_mv = neg_voltage_uv / 1000;
 	} else if (pdata) {
@@ -394,97 +530,82 @@ static int ad5791_probe(struct spi_device *spi)
 		dev_warn(&spi->dev, "reference voltage unspecified\n");
 	}
 
-	ret = ad5791_spi_write(spi, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
-	if (ret)
-		goto error_disable_reg_neg;
-
-	st->chip_info =	&ad5791_chip_info_tbl[spi_get_device_id(spi)
-					      ->driver_data];
+	if (st->gpio_reset) {
+		fsleep(20);
+		gpiod_set_value_cansleep(st->gpio_reset, 0);
+	} else {
+		ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
+		if (ret)
+			return dev_err_probe(&spi->dev, ret, "fail to reset\n");
+	}
 
+	st->chip_info = spi_get_device_match_data(spi);
+	if (!st->chip_info)
+		return dev_err_probe(&spi->dev, -EINVAL, "no chip info\n");
 
 	st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv))
-		  | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
+		  | (use_rbuf_gain2 ? 0 : AD5791_CTRL_RBUF) |
 		  AD5791_CTRL_BIN2SC;
 
-	ret = ad5791_spi_write(spi, AD5791_ADDR_CTRL, st->ctrl |
+	ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl |
 		AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
 	if (ret)
-		goto error_disable_reg_neg;
+		return dev_err_probe(&spi->dev, ret, "fail to write ctrl register\n");
 
-	spi_set_drvdata(spi, indio_dev);
-	indio_dev->dev.parent = &spi->dev;
 	indio_dev->info = &ad5791_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels
-		= &ad5791_channels[spi_get_device_id(spi)->driver_data];
+	indio_dev->channels = &st->chip_info->channel;
 	indio_dev->num_channels = 1;
-	indio_dev->name = spi_get_device_id(st->spi)->name;
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto error_disable_reg_neg;
-
-	return 0;
-
-error_disable_reg_neg:
-	if (!IS_ERR(st->reg_vss))
-		regulator_disable(st->reg_vss);
-error_put_reg_neg:
-	if (!IS_ERR(st->reg_vss))
-		regulator_put(st->reg_vss);
-
-error_disable_reg_pos:
-	if (!IS_ERR(st->reg_vdd))
-		regulator_disable(st->reg_vdd);
-error_put_reg_pos:
-	if (!IS_ERR(st->reg_vdd))
-		regulator_put(st->reg_vdd);
-	iio_device_free(indio_dev);
-error_ret:
+	indio_dev->name = st->chip_info->name;
 
-	return ret;
-}
+	st->offload = devm_spi_offload_get(&spi->dev, spi, &ad5791_offload_config);
+	ret = PTR_ERR_OR_ZERO(st->offload);
+	if (ret && ret != -ENODEV)
+		return dev_err_probe(&spi->dev, ret, "failed to get offload\n");
 
-static int ad5791_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct ad5791_state *st = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	if (!IS_ERR(st->reg_vdd)) {
-		regulator_disable(st->reg_vdd);
-		regulator_put(st->reg_vdd);
-	}
-
-	if (!IS_ERR(st->reg_vss)) {
-		regulator_disable(st->reg_vss);
-		regulator_put(st->reg_vss);
+	if (ret != -ENODEV) {
+		indio_dev->channels = &st->chip_info->channel_offload;
+		indio_dev->setup_ops = &ad5791_buffer_setup_ops;
+		ret = ad5791_offload_setup(indio_dev);
+		if (ret)
+			return dev_err_probe(&spi->dev, ret,
+					     "fail to setup offload\n");
 	}
-	iio_device_free(indio_dev);
 
-	return 0;
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
+static const struct of_device_id ad5791_of_match[] = {
+	{ .compatible = "adi,ad5760", .data = &ad5760_chip_info },
+	{ .compatible = "adi,ad5780", .data = &ad5780_chip_info },
+	{ .compatible = "adi,ad5781", .data = &ad5781_chip_info },
+	{ .compatible = "adi,ad5790", .data = &ad5790_chip_info },
+	{ .compatible = "adi,ad5791", .data = &ad5791_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ad5791_of_match);
+
 static const struct spi_device_id ad5791_id[] = {
-	{"ad5760", ID_AD5760},
-	{"ad5780", ID_AD5780},
-	{"ad5781", ID_AD5781},
-	{"ad5790", ID_AD5791},
-	{"ad5791", ID_AD5791},
-	{}
+	{ "ad5760", (kernel_ulong_t)&ad5760_chip_info },
+	{ "ad5780", (kernel_ulong_t)&ad5780_chip_info },
+	{ "ad5781", (kernel_ulong_t)&ad5781_chip_info },
+	{ "ad5790", (kernel_ulong_t)&ad5790_chip_info },
+	{ "ad5791", (kernel_ulong_t)&ad5791_chip_info },
+	{ }
 };
 MODULE_DEVICE_TABLE(spi, ad5791_id);
 
 static struct spi_driver ad5791_driver = {
 	.driver = {
 		   .name = "ad5791",
-		   .owner = THIS_MODULE,
+		   .of_match_table = ad5791_of_match,
 		   },
 	.probe = ad5791_probe,
-	.remove = ad5791_remove,
 	.id_table = ad5791_id,
 };
 module_spi_driver(ad5791_driver);
 
-MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");