Commit cbbb8198 authored by Alexandru Tachici's avatar Alexandru Tachici Committed by Jonathan Cameron
Browse files

iio: dac: ad5770r: Add AD5770R support 



The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable
current output digital-to-analog converter (DAC) for photonics control
applications.

It contains five 14-bit resolution current sourcing DAC channels and one
14-bit resolution current sourcing/sinking DAC channel.

Signed-off-by: default avatarMircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: default avatarAlexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 070bd30a

drivers/iio/dac/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -209,6 +209,16 @@ config AD5764 
	  To compile this driver as a module, choose M here: the

	  module will be called ad5764.



config AD5770R

	tristate "Analog Devices AD5770R IDAC driver"

	depends on SPI_MASTER

	help

	  Say yes here to build support for Analog Devices AD5770R Digital to

	  Analog Converter.



	  To compile this driver as a module, choose M here: the

	  module will be called ad5770r.



config AD5791

	tristate "Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC SPI driver"

	depends on SPI

drivers/iio/dac/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ obj-$(CONFIG_AD5755) += ad5755.o 
obj-$(CONFIG_AD5755) += ad5758.o

obj-$(CONFIG_AD5761) += ad5761.o

obj-$(CONFIG_AD5764) += ad5764.o

obj-$(CONFIG_AD5770R) += ad5770r.o

obj-$(CONFIG_AD5791) += ad5791.o

obj-$(CONFIG_AD5686) += ad5686.o

obj-$(CONFIG_AD5686_SPI) += ad5686-spi.o

drivers/iio/dac/ad5770r.c

0 → 100644
+695 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * AD5770R Digital to analog converters driver

 *

 * Copyright 2018 Analog Devices Inc.

 */



#include <linux/bits.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/gpio/consumer.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/property.h>

#include <linux/regmap.h>

#include <linux/regulator/consumer.h>

#include <linux/spi/spi.h>



#define ADI_SPI_IF_CONFIG_A		0x00

#define ADI_SPI_IF_CONFIG_B		0x01

#define ADI_SPI_IF_DEVICE_CONFIG	0x02

#define ADI_SPI_IF_CHIP_TYPE		0x03

#define ADI_SPI_IF_PRODUCT_ID_L		0x04

#define ADI_SPI_IF_PRODUCT_ID_H		0x05

#define ADI_SPI_IF_CHIP_GRADE		0x06

#define ADI_SPI_IF_SCRACTH_PAD		0x0A

#define ADI_SPI_IF_SPI_REVISION		0x0B

#define ADI_SPI_IF_SPI_VENDOR_L		0x0C

#define ADI_SPI_IF_SPI_VENDOR_H		0x0D

#define ADI_SPI_IF_SPI_STREAM_MODE	0x0E

#define ADI_SPI_IF_CONFIG_C		0x10

#define ADI_SPI_IF_STATUS_A		0x11



/* ADI_SPI_IF_CONFIG_A */

#define ADI_SPI_IF_SW_RESET_MSK		(BIT(0) | BIT(7))

#define ADI_SPI_IF_SW_RESET_SEL(x)	((x) & ADI_SPI_IF_SW_RESET_MSK)

#define ADI_SPI_IF_ADDR_ASC_MSK		(BIT(2) | BIT(5))

#define ADI_SPI_IF_ADDR_ASC_SEL(x)	(((x) << 2) & ADI_SPI_IF_ADDR_ASC_MSK)



/* ADI_SPI_IF_CONFIG_B */

#define ADI_SPI_IF_SINGLE_INS_MSK	BIT(7)

#define ADI_SPI_IF_SINGLE_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)

#define ADI_SPI_IF_SHORT_INS_MSK	BIT(7)

#define ADI_SPI_IF_SHORT_INS_SEL(x)	FIELD_PREP(ADI_SPI_IF_SINGLE_INS_MSK, x)



/* ADI_SPI_IF_CONFIG_C */

#define ADI_SPI_IF_STRICT_REG_MSK	BIT(5)

#define ADI_SPI_IF_STRICT_REG_GET(x)	FIELD_GET(ADI_SPI_IF_STRICT_REG_MSK, x)



/* AD5770R configuration registers */

#define AD5770R_CHANNEL_CONFIG		0x14

#define AD5770R_OUTPUT_RANGE(ch)	(0x15 + (ch))

#define AD5770R_FILTER_RESISTOR(ch)	(0x1D + (ch))

#define AD5770R_REFERENCE		0x1B

#define AD5770R_DAC_LSB(ch)		(0x26 + 2 * (ch))

#define AD5770R_DAC_MSB(ch)		(0x27 + 2 * (ch))

#define AD5770R_CH_SELECT		0x34

#define AD5770R_CH_ENABLE		0x44



/* AD5770R_CHANNEL_CONFIG */

#define AD5770R_CFG_CH0_SINK_EN(x)		(((x) & 0x1) << 7)

#define AD5770R_CFG_SHUTDOWN_B(x, ch)		(((x) & 0x1) << (ch))



/* AD5770R_OUTPUT_RANGE */

#define AD5770R_RANGE_OUTPUT_SCALING(x)		(((x) & GENMASK(5, 0)) << 2)

#define AD5770R_RANGE_MODE(x)			((x) & GENMASK(1, 0))



/* AD5770R_REFERENCE */

#define AD5770R_REF_RESISTOR_SEL(x)		(((x) & 0x1) << 2)

#define AD5770R_REF_SEL(x)			((x) & GENMASK(1, 0))



/* AD5770R_CH_ENABLE */

#define AD5770R_CH_SET(x, ch)		(((x) & 0x1) << (ch))



#define AD5770R_MAX_CHANNELS	6

#define AD5770R_MAX_CH_MODES	14

#define AD5770R_LOW_VREF_mV	1250

#define AD5770R_HIGH_VREF_mV	2500



enum ad5770r_ch0_modes {

	AD5770R_CH0_0_300 = 0,

	AD5770R_CH0_NEG_60_0,

	AD5770R_CH0_NEG_60_300

};



enum ad5770r_ch1_modes {

	AD5770R_CH1_0_140_LOW_HEAD = 1,

	AD5770R_CH1_0_140_LOW_NOISE,

	AD5770R_CH1_0_250

};



enum ad5770r_ch2_5_modes {

	AD5770R_CH_LOW_RANGE = 0,

	AD5770R_CH_HIGH_RANGE

};



enum ad5770r_ref_v {

	AD5770R_EXT_2_5_V = 0,

	AD5770R_INT_1_25_V_OUT_ON,

	AD5770R_EXT_1_25_V,

	AD5770R_INT_1_25_V_OUT_OFF

};



enum ad5770r_output_filter_resistor {

	AD5770R_FILTER_60_OHM = 0x0,

	AD5770R_FILTER_5_6_KOHM = 0x5,

	AD5770R_FILTER_11_2_KOHM,

	AD5770R_FILTER_22_2_KOHM,

	AD5770R_FILTER_44_4_KOHM,

	AD5770R_FILTER_104_KOHM,

};



struct ad5770r_out_range {

	u8	out_scale;

	u8	out_range_mode;

};



/**

 * struct ad5770R_state - driver instance specific data

 * @spi:		spi_device

 * @regmap:		regmap

 * @vref_reg:		fixed regulator for reference configuration

 * @gpio_reset:		gpio descriptor

 * @output_mode:	array contains channels output ranges

 * @vref:		reference value

 * @ch_pwr_down:	powerdown flags

 * @internal_ref:	internal reference flag

 * @external_res:	external 2.5k resistor flag

 * @transf_buf:		cache aligned buffer for spi read/write

 */

struct ad5770r_state {

	struct spi_device		*spi;

	struct regmap			*regmap;

	struct regulator		*vref_reg;

	struct gpio_desc		*gpio_reset;

	struct ad5770r_out_range	output_mode[AD5770R_MAX_CHANNELS];

	int				vref;

	bool				ch_pwr_down[AD5770R_MAX_CHANNELS];

	bool				internal_ref;

	bool				external_res;

	u8				transf_buf[2] ____cacheline_aligned;

};



static const struct regmap_config ad5770r_spi_regmap_config = {

	.reg_bits = 8,

	.val_bits = 8,

	.read_flag_mask = BIT(7),

};



struct ad5770r_output_modes {

	unsigned int ch;

	u8 mode;

	int min;

	int max;

};



static struct ad5770r_output_modes ad5770r_rng_tbl[] = {

	{ 0, AD5770R_CH0_0_300, 0, 300 },

	{ 0, AD5770R_CH0_NEG_60_0, -60, 0 },

	{ 0, AD5770R_CH0_NEG_60_300, -60, 300 },

	{ 1, AD5770R_CH1_0_140_LOW_HEAD, 0, 140 },

	{ 1, AD5770R_CH1_0_140_LOW_NOISE, 0, 140 },

	{ 1, AD5770R_CH1_0_250, 0, 250 },

	{ 2, AD5770R_CH_LOW_RANGE, 0, 55 },

	{ 2, AD5770R_CH_HIGH_RANGE, 0, 150 },

	{ 3, AD5770R_CH_LOW_RANGE, 0, 45 },

	{ 3, AD5770R_CH_HIGH_RANGE, 0, 100 },

	{ 4, AD5770R_CH_LOW_RANGE, 0, 45 },

	{ 4, AD5770R_CH_HIGH_RANGE, 0, 100 },

	{ 5, AD5770R_CH_LOW_RANGE, 0, 45 },

	{ 5, AD5770R_CH_HIGH_RANGE, 0, 100 },

};



static const unsigned int ad5770r_filter_freqs[] = {

	153, 357, 715, 1400, 2800, 262000,

};



static const unsigned int ad5770r_filter_reg_vals[] = {

	AD5770R_FILTER_104_KOHM,

	AD5770R_FILTER_44_4_KOHM,

	AD5770R_FILTER_22_2_KOHM,

	AD5770R_FILTER_11_2_KOHM,

	AD5770R_FILTER_5_6_KOHM,

	AD5770R_FILTER_60_OHM

};



static int ad5770r_set_output_mode(struct ad5770r_state *st,

				   const struct ad5770r_out_range *out_mode,

				   int channel)

{

	unsigned int regval;



	regval = AD5770R_RANGE_OUTPUT_SCALING(out_mode->out_scale) |

		 AD5770R_RANGE_MODE(out_mode->out_range_mode);



	return regmap_write(st->regmap,

			    AD5770R_OUTPUT_RANGE(channel), regval);

}



static int ad5770r_set_reference(struct ad5770r_state *st)

{

	unsigned int regval;



	regval = AD5770R_REF_RESISTOR_SEL(st->external_res);



	if (st->internal_ref) {

		regval |= AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);

	} else {

		switch (st->vref) {

		case AD5770R_LOW_VREF_mV:

			regval |= AD5770R_REF_SEL(AD5770R_EXT_1_25_V);

			break;

		case AD5770R_HIGH_VREF_mV:

			regval |= AD5770R_REF_SEL(AD5770R_EXT_2_5_V);

			break;

		default:

			regval = AD5770R_REF_SEL(AD5770R_INT_1_25_V_OUT_OFF);

			break;

		}

	}



	return regmap_write(st->regmap, AD5770R_REFERENCE, regval);

}



static int ad5770r_soft_reset(struct ad5770r_state *st)

{

	return regmap_write(st->regmap, ADI_SPI_IF_CONFIG_A,

			    ADI_SPI_IF_SW_RESET_SEL(1));

}



static int ad5770r_reset(struct ad5770r_state *st)

{

	/* Perform software reset if no GPIO provided */

	if (!st->gpio_reset)

		return ad5770r_soft_reset(st);



	gpiod_set_value_cansleep(st->gpio_reset, 0);

	usleep_range(10, 20);

	gpiod_set_value_cansleep(st->gpio_reset, 1);



	/* data must not be written during reset timeframe */

	usleep_range(100, 200);



	return 0;

}



static int ad5770r_get_range(struct ad5770r_state *st,

			     int ch, int *min, int *max)

{

	int i;

	u8 tbl_ch, tbl_mode, out_range;



	out_range = st->output_mode[ch].out_range_mode;



	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {

		tbl_ch = ad5770r_rng_tbl[i].ch;

		tbl_mode = ad5770r_rng_tbl[i].mode;

		if (tbl_ch == ch && tbl_mode == out_range) {

			*min = ad5770r_rng_tbl[i].min;

			*max = ad5770r_rng_tbl[i].max;

			return 0;

		}

	}



	return -EINVAL;

}



static int ad5770r_get_filter_freq(struct iio_dev *indio_dev,

				   const struct iio_chan_spec *chan, int *freq)

{

	struct ad5770r_state *st = iio_priv(indio_dev);

	int ret;

	unsigned int regval, i;



	ret = regmap_read(st->regmap,

			  AD5770R_FILTER_RESISTOR(chan->channel), &regval);

	if (ret < 0)

		return ret;



	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_reg_vals); i++)

		if (regval == ad5770r_filter_reg_vals[i])

			break;

	if (i == ARRAY_SIZE(ad5770r_filter_reg_vals))

		return -EINVAL;



	*freq = ad5770r_filter_freqs[i];



	return IIO_VAL_INT;

}



static int ad5770r_set_filter_freq(struct iio_dev *indio_dev,

				   const struct iio_chan_spec *chan,

				   unsigned int freq)

{

	struct ad5770r_state *st = iio_priv(indio_dev);

	unsigned int regval, i;



	for (i = 0; i < ARRAY_SIZE(ad5770r_filter_freqs); i++)

		if (ad5770r_filter_freqs[i] >= freq)

			break;

	if (i == ARRAY_SIZE(ad5770r_filter_freqs))

		return -EINVAL;



	regval = ad5770r_filter_reg_vals[i];



	return regmap_write(st->regmap, AD5770R_FILTER_RESISTOR(chan->channel),

			    regval);

}



static int ad5770r_read_raw(struct iio_dev *indio_dev,

			    struct iio_chan_spec const *chan,

			    int *val, int *val2, long info)

{

	struct ad5770r_state *st = iio_priv(indio_dev);

	int max, min, ret;

	u16 buf16;



	switch (info) {

	case IIO_CHAN_INFO_RAW:

		ret = regmap_bulk_read(st->regmap,

				       chan->address,

				       st->transf_buf, 2);

		if (ret)

			return 0;



		buf16 = st->transf_buf[0] + (st->transf_buf[1] << 8);

		*val = buf16 >> 2;

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		ret = ad5770r_get_range(st, chan->channel, &min, &max);

		if (ret < 0)

			return ret;

		*val = max - min;

		/* There is no sign bit. (negative current is mapped from 0)

		 * (sourced/sinked) current = raw * scale + offset

		 * where offset in case of CH0 can be negative.

		 */

		*val2 = 14;

		return IIO_VAL_FRACTIONAL_LOG2;

	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:

		return ad5770r_get_filter_freq(indio_dev, chan, val);

	case IIO_CHAN_INFO_OFFSET:

		ret = ad5770r_get_range(st, chan->channel, &min, &max);

		if (ret < 0)

			return ret;

		*val = min;

		return IIO_VAL_INT;

	default:

		return -EINVAL;

	}

}



static int ad5770r_write_raw(struct iio_dev *indio_dev,

			     struct iio_chan_spec const *chan,

			     int val, int val2, long info)

{

	struct ad5770r_state *st = iio_priv(indio_dev);



	switch (info) {

	case IIO_CHAN_INFO_RAW:

		st->transf_buf[0] = ((u16)val >> 6);

		st->transf_buf[1] = (val & GENMASK(5, 0)) << 2;

		return regmap_bulk_write(st->regmap, chan->address,

					 st->transf_buf, 2);

	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:

		return ad5770r_set_filter_freq(indio_dev, chan, val);

	default:

		return -EINVAL;

	}

}



static int ad5770r_read_freq_avail(struct iio_dev *indio_dev,

				   struct iio_chan_spec const *chan,

				   const int **vals, int *type, int *length,

				   long mask)

{

	switch (mask) {

	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:

		*type = IIO_VAL_INT;

		*vals = ad5770r_filter_freqs;

		*length = ARRAY_SIZE(ad5770r_filter_freqs);

		return IIO_AVAIL_LIST;

	}



	return -EINVAL;

}



static int ad5770r_reg_access(struct iio_dev *indio_dev,

			      unsigned int reg,

			      unsigned int writeval,

			      unsigned int *readval)

{

	struct ad5770r_state *st = iio_priv(indio_dev);



	if (readval)

		return regmap_read(st->regmap, reg, readval);

	else

		return regmap_write(st->regmap, reg, writeval);

}



static const struct iio_info ad5770r_info = {

	.read_raw = ad5770r_read_raw,

	.write_raw = ad5770r_write_raw,

	.read_avail = ad5770r_read_freq_avail,

	.debugfs_reg_access = &ad5770r_reg_access,

};



static int ad5770r_store_output_range(struct ad5770r_state *st,

				      int min, int max, int index)

{

	int i;



	for (i = 0; i < AD5770R_MAX_CH_MODES; i++) {

		if (ad5770r_rng_tbl[i].ch != index)

			continue;

		if (ad5770r_rng_tbl[i].min != min ||

		    ad5770r_rng_tbl[i].max != max)

			continue;

		st->output_mode[index].out_range_mode = ad5770r_rng_tbl[i].mode;



		return 0;

	}



	return -EINVAL;

}



static ssize_t ad5770r_read_dac_powerdown(struct iio_dev *indio_dev,

					  uintptr_t private,

					  const struct iio_chan_spec *chan,

					  char *buf)

{

	struct ad5770r_state *st = iio_priv(indio_dev);



	return sprintf(buf, "%d\n", st->ch_pwr_down[chan->channel]);

}



static ssize_t ad5770r_write_dac_powerdown(struct iio_dev *indio_dev,

					   uintptr_t private,

					   const struct iio_chan_spec *chan,

					   const char *buf, size_t len)

{

	struct ad5770r_state *st = iio_priv(indio_dev);

	unsigned int regval;

	unsigned int mask;

	bool readin;

	int ret;



	ret = kstrtobool(buf, &readin);

	if (ret)

		return ret;



	readin = !readin;



	regval = AD5770R_CFG_SHUTDOWN_B(readin, chan->channel);

	if (chan->channel == 0 &&

	    st->output_mode[0].out_range_mode > AD5770R_CH0_0_300) {

		regval |= AD5770R_CFG_CH0_SINK_EN(readin);

		mask = BIT(chan->channel) + BIT(7);

	} else {

		mask = BIT(chan->channel);

	}

	ret = regmap_update_bits(st->regmap, AD5770R_CHANNEL_CONFIG, mask,

				 regval);

	if (ret)

		return ret;



	regval = AD5770R_CH_SET(readin, chan->channel);

	ret = regmap_update_bits(st->regmap, AD5770R_CH_ENABLE,

				 BIT(chan->channel), regval);

	if (ret)

		return ret;



	st->ch_pwr_down[chan->channel] = !readin;



	return len;

}



static const struct iio_chan_spec_ext_info ad5770r_ext_info[] = {

	{

		.name = "powerdown",

		.read = ad5770r_read_dac_powerdown,

		.write = ad5770r_write_dac_powerdown,

		.shared = IIO_SEPARATE,

	},

	{ }

};



#define AD5770R_IDAC_CHANNEL(index, reg) {				\

	.type = IIO_CURRENT,						\

	.address = reg,							\

	.indexed = 1,							\

	.channel = index,						\

	.output = 1,							\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\

		BIT(IIO_CHAN_INFO_SCALE) |				\

		BIT(IIO_CHAN_INFO_OFFSET) |				\

		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\

	.info_mask_shared_by_type_available =				\

		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\

	.ext_info = ad5770r_ext_info,					\

}



static const struct iio_chan_spec ad5770r_channels[] = {

	AD5770R_IDAC_CHANNEL(0, AD5770R_DAC_MSB(0)),

	AD5770R_IDAC_CHANNEL(1, AD5770R_DAC_MSB(1)),

	AD5770R_IDAC_CHANNEL(2, AD5770R_DAC_MSB(2)),

	AD5770R_IDAC_CHANNEL(3, AD5770R_DAC_MSB(3)),

	AD5770R_IDAC_CHANNEL(4, AD5770R_DAC_MSB(4)),

	AD5770R_IDAC_CHANNEL(5, AD5770R_DAC_MSB(5)),

};



static int ad5770r_channel_config(struct ad5770r_state *st)

{

	int ret, tmp[2], min, max;

	unsigned int num;

	struct fwnode_handle *child;



	num = device_get_child_node_count(&st->spi->dev);

	if (num != AD5770R_MAX_CHANNELS)

		return -EINVAL;



	device_for_each_child_node(&st->spi->dev, child) {

		ret = fwnode_property_read_u32(child, "num", &num);

		if (ret)

			return ret;

		if (num > AD5770R_MAX_CHANNELS)

			return -EINVAL;



		ret = fwnode_property_read_u32_array(child,

						     "adi,range-microamp",

						     tmp, 2);

		if (ret)

			return ret;



		min = tmp[0] / 1000;

		max = tmp[1] / 1000;

		ret = ad5770r_store_output_range(st, min, max, num);

		if (ret)

			return ret;

	}



	return ret;

}



static int ad5770r_init(struct ad5770r_state *st)

{

	int ret, i;



	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",

						 GPIOD_OUT_HIGH);

	if (IS_ERR(st->gpio_reset))

		return PTR_ERR(st->gpio_reset);



	/* Perform a reset */

	ret = ad5770r_reset(st);

	if (ret)

		return ret;



	/* Set output range */

	ret = ad5770r_channel_config(st);

	if (ret)

		return ret;



	for (i = 0; i < AD5770R_MAX_CHANNELS; i++) {

		ret = ad5770r_set_output_mode(st,  &st->output_mode[i], i);

		if (ret)

			return ret;

	}



	st->external_res = fwnode_property_read_bool(st->spi->dev.fwnode,

						     "adi,external-resistor");



	ret = ad5770r_set_reference(st);

	if (ret)

		return ret;



	/* Set outputs off */

	ret = regmap_write(st->regmap, AD5770R_CHANNEL_CONFIG, 0x00);

	if (ret)

		return ret;



	ret = regmap_write(st->regmap, AD5770R_CH_ENABLE, 0x00);

	if (ret)

		return ret;



	for (i = 0; i < AD5770R_MAX_CHANNELS; i++)

		st->ch_pwr_down[i] = true;



	return ret;

}



static void ad5770r_disable_regulator(void *data)

{

	struct ad5770r_state *st = data;



	regulator_disable(st->vref_reg);

}



static int ad5770r_probe(struct spi_device *spi)

{

	struct ad5770r_state *st;

	struct iio_dev *indio_dev;

	struct regmap *regmap;

	int ret;



	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));

	if (!indio_dev)

		return -ENOMEM;



	st = iio_priv(indio_dev);

	spi_set_drvdata(spi, indio_dev);



	st->spi = spi;



	regmap = devm_regmap_init_spi(spi, &ad5770r_spi_regmap_config);

	if (IS_ERR(regmap)) {

		dev_err(&spi->dev, "Error initializing spi regmap: %ld\n",

			PTR_ERR(regmap));

		return PTR_ERR(regmap);

	}

	st->regmap = regmap;



	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");

	if (!IS_ERR(st->vref_reg)) {

		ret = regulator_enable(st->vref_reg);

		if (ret) {

			dev_err(&spi->dev,

				"Failed to enable vref regulators: %d\n", ret);

			return ret;

		}



		ret = devm_add_action_or_reset(&spi->dev,

					       ad5770r_disable_regulator,

					       st);

		if (ret < 0)

			return ret;



		ret = regulator_get_voltage(st->vref_reg);

		if (ret < 0)

			return ret;



		st->vref = ret / 1000;

	} else {

		if (PTR_ERR(st->vref_reg) == -ENODEV) {

			st->vref = AD5770R_LOW_VREF_mV;

			st->internal_ref = true;

		} else {

			return PTR_ERR(st->vref_reg);

		}

	}



	indio_dev->dev.parent = &spi->dev;

	indio_dev->name = spi_get_device_id(spi)->name;

	indio_dev->info = &ad5770r_info;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->channels = ad5770r_channels;

	indio_dev->num_channels = ARRAY_SIZE(ad5770r_channels);



	ret = ad5770r_init(st);

	if (ret < 0) {

		dev_err(&spi->dev, "AD5770R init failed\n");

		return ret;

	}



	return devm_iio_device_register(&st->spi->dev, indio_dev);

}



static const struct of_device_id ad5770r_of_id[] = {

	{ .compatible = "adi,ad5770r", },

	{},

};

MODULE_DEVICE_TABLE(of, ad5770r_of_id);



static const struct spi_device_id ad5770r_id[] = {

	{ "ad5770r", 0 },

	{},

};

MODULE_DEVICE_TABLE(spi, ad5770r_id);



static struct spi_driver ad5770r_driver = {

	.driver = {

		.name = KBUILD_MODNAME,

		.of_match_table = ad5770r_of_id,

	},

	.probe = ad5770r_probe,

	.id_table = ad5770r_id,

};



module_spi_driver(ad5770r_driver);



MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");

MODULE_DESCRIPTION("Analog Devices AD5770R IDAC");

MODULE_LICENSE("GPL v2");