kernel / drivers / iio / dac / ltc2664.c

// SPDX-License-Identifier: GPL-2.0
/*
 * LTC2664 4 channel, 12-/16-Bit Voltage Output SoftSpan DAC driver
 * LTC2672 5 channel, 12-/16-Bit Current Output Softspan DAC driver
 *
 * Copyright 2024 Analog Devices Inc.
 */

#include <linux/bitfield.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/iio/iio.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>

#define LTC2664_CMD_WRITE_N(n)		(0x00 + (n))
#define LTC2664_CMD_UPDATE_N(n)		(0x10 + (n))
#define LTC2664_CMD_WRITE_N_UPDATE_ALL	0x20
#define LTC2664_CMD_WRITE_N_UPDATE_N(n)	(0x30 + (n))
#define LTC2664_CMD_POWER_DOWN_N(n)	(0x40 + (n))
#define LTC2664_CMD_POWER_DOWN_ALL	0x50
#define LTC2664_CMD_SPAN_N(n)		(0x60 + (n))
#define LTC2664_CMD_CONFIG		0x70
#define LTC2664_CMD_MUX			0xB0
#define LTC2664_CMD_TOGGLE_SEL		0xC0
#define LTC2664_CMD_GLOBAL_TOGGLE	0xD0
#define LTC2664_CMD_NO_OPERATION	0xF0
#define LTC2664_REF_DISABLE		0x0001
#define LTC2664_MSPAN_SOFTSPAN		7

#define LTC2672_MAX_CHANNEL		5
#define LTC2672_MAX_SPAN		7
#define LTC2672_SCALE_MULTIPLIER(n)	(50 * BIT(n))

enum {
	LTC2664_SPAN_RANGE_0V_5V,
	LTC2664_SPAN_RANGE_0V_10V,
	LTC2664_SPAN_RANGE_M5V_5V,
	LTC2664_SPAN_RANGE_M10V_10V,
	LTC2664_SPAN_RANGE_M2V5_2V5,
};

enum {
	LTC2664_INPUT_A,
	LTC2664_INPUT_B,
	LTC2664_INPUT_B_AVAIL,
	LTC2664_POWERDOWN,
	LTC2664_POWERDOWN_MODE,
	LTC2664_TOGGLE_EN,
	LTC2664_GLOBAL_TOGGLE,
};

static const u16 ltc2664_mspan_lut[8][2] = {
	{ LTC2664_SPAN_RANGE_M10V_10V, 32768 }, /* MPS2=0, MPS1=0, MSP0=0 (0)*/
	{ LTC2664_SPAN_RANGE_M5V_5V, 32768 }, /* MPS2=0, MPS1=0, MSP0=1 (1)*/
	{ LTC2664_SPAN_RANGE_M2V5_2V5, 32768 }, /* MPS2=0, MPS1=1, MSP0=0 (2)*/
	{ LTC2664_SPAN_RANGE_0V_10V, 0 }, /* MPS2=0, MPS1=1, MSP0=1 (3)*/
	{ LTC2664_SPAN_RANGE_0V_10V, 32768 }, /* MPS2=1, MPS1=0, MSP0=0 (4)*/
	{ LTC2664_SPAN_RANGE_0V_5V, 0 }, /* MPS2=1, MPS1=0, MSP0=1 (5)*/
	{ LTC2664_SPAN_RANGE_0V_5V, 32768 }, /* MPS2=1, MPS1=1, MSP0=0 (6)*/
	{ LTC2664_SPAN_RANGE_0V_5V, 0 } /* MPS2=1, MPS1=1, MSP0=1 (7)*/
};

struct ltc2664_state;

struct ltc2664_chip_info {
	const char *name;
	int (*scale_get)(const struct ltc2664_state *st, int c);
	int (*offset_get)(const struct ltc2664_state *st, int c);
	int measurement_type;
	unsigned int num_channels;
	const int (*span_helper)[2];
	unsigned int num_span;
	unsigned int internal_vref_mv;
	bool manual_span_support;
	bool rfsadj_support;
};

struct ltc2664_chan {
	/* indicates if the channel should be toggled */
	bool toggle_chan;
	/* indicates if the channel is in powered down state */
	bool powerdown;
	/* span code of the channel */
	u8 span;
	/* raw data of the current state of the chip registers (A/B) */
	u16 raw[2];
};

struct ltc2664_state {
	struct spi_device *spi;
	struct regmap *regmap;
	struct ltc2664_chan channels[LTC2672_MAX_CHANNEL];
	/* lock to protect against multiple access to the device and shared data */
	struct mutex lock;
	const struct ltc2664_chip_info *chip_info;
	struct iio_chan_spec *iio_channels;
	int vref_mv;
	u32 rfsadj_ohms;
	u32 toggle_sel;
	bool global_toggle;
};

static const int ltc2664_span_helper[][2] = {
	{ 0, 5000 },
	{ 0, 10000 },
	{ -5000, 5000 },
	{ -10000, 10000 },
	{ -2500, 2500 },
};

static const int ltc2672_span_helper[][2] = {
	{ 0, 0 },
	{ 0, 3125 },
	{ 0, 6250 },
	{ 0, 12500 },
	{ 0, 25000 },
	{ 0, 50000 },
	{ 0, 100000 },
	{ 0, 200000 },
	{ 0, 300000 },
};

static int ltc2664_scale_get(const struct ltc2664_state *st, int c)
{
	const struct ltc2664_chan *chan = &st->channels[c];
	const int (*span_helper)[2] = st->chip_info->span_helper;
	int span, fs;

	span = chan->span;
	if (span < 0)
		return span;

	fs = span_helper[span][1] - span_helper[span][0];

	return fs * st->vref_mv / 2500;
}

static int ltc2672_scale_get(const struct ltc2664_state *st, int c)
{
	const struct ltc2664_chan *chan = &st->channels[c];
	int span, fs;

	span = chan->span - 1;
	if (span < 0)
		return span;

	fs = 1000 * st->vref_mv;

	if (span == LTC2672_MAX_SPAN)
		return mul_u64_u32_div(4800, fs, st->rfsadj_ohms);

	return mul_u64_u32_div(LTC2672_SCALE_MULTIPLIER(span), fs, st->rfsadj_ohms);
}

static int ltc2664_offset_get(const struct ltc2664_state *st, int c)
{
	const struct ltc2664_chan *chan = &st->channels[c];
	int span;

	span = chan->span;
	if (span < 0)
		return span;

	if (st->chip_info->span_helper[span][0] < 0)
		return -32768;

	return 0;
}

static int ltc2664_dac_code_write(struct ltc2664_state *st, u32 chan, u32 input,
				  u16 code)
{
	struct ltc2664_chan *c = &st->channels[chan];
	int ret, reg;

	guard(mutex)(&st->lock);
	/* select the correct input register to write to */
	if (c->toggle_chan) {
		ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
				   input << chan);
		if (ret)
			return ret;
	}
	/*
	 * If in toggle mode the dac should be updated by an
	 * external signal (or sw toggle) and not here.
	 */
	if (st->toggle_sel & BIT(chan))
		reg = LTC2664_CMD_WRITE_N(chan);
	else
		reg = LTC2664_CMD_WRITE_N_UPDATE_N(chan);

	ret = regmap_write(st->regmap, reg, code);
	if (ret)
		return ret;

	c->raw[input] = code;

	if (c->toggle_chan) {
		ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
				   st->toggle_sel);
		if (ret)
			return ret;
	}

	return 0;
}

static void ltc2664_dac_code_read(struct ltc2664_state *st, u32 chan, u32 input,
				  u32 *code)
{
	guard(mutex)(&st->lock);
	*code = st->channels[chan].raw[input];
}

static const int ltc2664_raw_range[] = { 0, 1, U16_MAX };

static int ltc2664_read_avail(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      const int **vals, int *type, int *length,
			      long info)
{
	switch (info) {
	case IIO_CHAN_INFO_RAW:
		*vals = ltc2664_raw_range;
		*type = IIO_VAL_INT;

		return IIO_AVAIL_RANGE;
	default:
		return -EINVAL;
	}
}

static int ltc2664_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan, int *val,
			    int *val2, long info)
{
	struct ltc2664_state *st = iio_priv(indio_dev);

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		ltc2664_dac_code_read(st, chan->channel, LTC2664_INPUT_A, val);

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_OFFSET:
		*val = st->chip_info->offset_get(st, chan->channel);

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = st->chip_info->scale_get(st, chan->channel);

		*val2 = 16;
		return IIO_VAL_FRACTIONAL_LOG2;
	default:
		return -EINVAL;
	}
}

static int ltc2664_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan, int val,
			     int val2, long info)
{
	struct ltc2664_state *st = iio_priv(indio_dev);

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		if (val > U16_MAX || val < 0)
			return -EINVAL;

		return ltc2664_dac_code_write(st, chan->channel,
					      LTC2664_INPUT_A, val);
	default:
		return -EINVAL;
	}
}

static ssize_t ltc2664_reg_bool_get(struct iio_dev *indio_dev,
				    uintptr_t private,
				    const struct iio_chan_spec *chan,
				    char *buf)
{
	struct ltc2664_state *st = iio_priv(indio_dev);
	u32 val;

	guard(mutex)(&st->lock);
	switch (private) {
	case LTC2664_POWERDOWN:
		val = st->channels[chan->channel].powerdown;

		return sysfs_emit(buf, "%u\n", val);
	case LTC2664_POWERDOWN_MODE:
		return sysfs_emit(buf, "42kohm_to_gnd\n");
	case LTC2664_TOGGLE_EN:
		val = !!(st->toggle_sel & BIT(chan->channel));

		return sysfs_emit(buf, "%u\n", val);
	case LTC2664_GLOBAL_TOGGLE:
		val = st->global_toggle;

		return sysfs_emit(buf, "%u\n", val);
	default:
		return -EINVAL;
	}
}

static ssize_t ltc2664_reg_bool_set(struct iio_dev *indio_dev,
				    uintptr_t private,
				    const struct iio_chan_spec *chan,
				    const char *buf, size_t len)
{
	struct ltc2664_state *st = iio_priv(indio_dev);
	int ret;
	bool en;

	ret = kstrtobool(buf, &en);
	if (ret)
		return ret;

	guard(mutex)(&st->lock);
	switch (private) {
	case LTC2664_POWERDOWN:
		ret = regmap_write(st->regmap,
				   en ? LTC2664_CMD_POWER_DOWN_N(chan->channel) :
				   LTC2664_CMD_UPDATE_N(chan->channel), en);
		if (ret)
			return ret;

		st->channels[chan->channel].powerdown = en;

		return len;
	case LTC2664_TOGGLE_EN:
		if (en)
			st->toggle_sel |= BIT(chan->channel);
		else
			st->toggle_sel &= ~BIT(chan->channel);

		ret = regmap_write(st->regmap, LTC2664_CMD_TOGGLE_SEL,
				   st->toggle_sel);
		if (ret)
			return ret;

		return len;
	case LTC2664_GLOBAL_TOGGLE:
		ret = regmap_write(st->regmap, LTC2664_CMD_GLOBAL_TOGGLE, en);
		if (ret)
			return ret;

		st->global_toggle = en;

		return len;
	default:
		return -EINVAL;
	}
}

static ssize_t ltc2664_dac_input_read(struct iio_dev *indio_dev,
				      uintptr_t private,
				      const struct iio_chan_spec *chan,
				      char *buf)
{
	struct ltc2664_state *st = iio_priv(indio_dev);
	u32 val;

	if (private == LTC2664_INPUT_B_AVAIL)
		return sysfs_emit(buf, "[%u %u %u]\n", ltc2664_raw_range[0],
				  ltc2664_raw_range[1],
				  ltc2664_raw_range[2] / 4);

	ltc2664_dac_code_read(st, chan->channel, private, &val);

	return sysfs_emit(buf, "%u\n", val);
}

static ssize_t ltc2664_dac_input_write(struct iio_dev *indio_dev,
				       uintptr_t private,
				       const struct iio_chan_spec *chan,
				       const char *buf, size_t len)
{
	struct ltc2664_state *st = iio_priv(indio_dev);
	int ret;
	u16 val;

	if (private == LTC2664_INPUT_B_AVAIL)
		return -EINVAL;

	ret = kstrtou16(buf, 10, &val);
	if (ret)
		return ret;

	ret = ltc2664_dac_code_write(st, chan->channel, private, val);
	if (ret)
		return ret;

	return len;
}

static int ltc2664_reg_access(struct iio_dev *indio_dev,
			      unsigned int reg,
			      unsigned int writeval,
			      unsigned int *readval)
{
	struct ltc2664_state *st = iio_priv(indio_dev);

	if (readval)
		return -EOPNOTSUPP;

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

#define LTC2664_CHAN_EXT_INFO(_name, _what, _shared, _read, _write) {	\
	.name = _name,							\
	.read = (_read),						\
	.write = (_write),						\
	.private = (_what),						\
	.shared = (_shared),						\
}

/*
 * For toggle mode we only expose the symbol attr (sw_toggle) in case a TGPx is
 * not provided in dts.
 */
static const struct iio_chan_spec_ext_info ltc2664_toggle_sym_ext_info[] = {
	LTC2664_CHAN_EXT_INFO("raw0", LTC2664_INPUT_A, IIO_SEPARATE,
			      ltc2664_dac_input_read, ltc2664_dac_input_write),
	LTC2664_CHAN_EXT_INFO("raw1", LTC2664_INPUT_B, IIO_SEPARATE,
			      ltc2664_dac_input_read, ltc2664_dac_input_write),
	LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
			      ltc2664_reg_bool_get, ltc2664_reg_bool_set),
	LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
			      IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
	LTC2664_CHAN_EXT_INFO("symbol", LTC2664_GLOBAL_TOGGLE, IIO_SEPARATE,
			      ltc2664_reg_bool_get, ltc2664_reg_bool_set),
	LTC2664_CHAN_EXT_INFO("toggle_en", LTC2664_TOGGLE_EN,
			      IIO_SEPARATE, ltc2664_reg_bool_get,
			      ltc2664_reg_bool_set),
	{ }
};

static const struct iio_chan_spec_ext_info ltc2664_ext_info[] = {
	LTC2664_CHAN_EXT_INFO("powerdown", LTC2664_POWERDOWN, IIO_SEPARATE,
			      ltc2664_reg_bool_get, ltc2664_reg_bool_set),
	LTC2664_CHAN_EXT_INFO("powerdown_mode", LTC2664_POWERDOWN_MODE,
			      IIO_SEPARATE, ltc2664_reg_bool_get, NULL),
	{ }
};

static const struct iio_chan_spec ltc2664_channel_template = {
	.indexed = 1,
	.output = 1,
	.info_mask_separate = BIT(IIO_CHAN_INFO_SCALE) |
			      BIT(IIO_CHAN_INFO_OFFSET) |
			      BIT(IIO_CHAN_INFO_RAW),
	.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
	.ext_info = ltc2664_ext_info,
};

static const struct ltc2664_chip_info ltc2664_chip = {
	.name = "ltc2664",
	.scale_get = ltc2664_scale_get,
	.offset_get = ltc2664_offset_get,
	.measurement_type = IIO_VOLTAGE,
	.num_channels = 4,
	.span_helper = ltc2664_span_helper,
	.num_span = ARRAY_SIZE(ltc2664_span_helper),
	.internal_vref_mv = 2500,
	.manual_span_support = true,
	.rfsadj_support = false,
};

static const struct ltc2664_chip_info ltc2672_chip = {
	.name = "ltc2672",
	.scale_get = ltc2672_scale_get,
	.offset_get = ltc2664_offset_get,
	.measurement_type = IIO_CURRENT,
	.num_channels = 5,
	.span_helper = ltc2672_span_helper,
	.num_span = ARRAY_SIZE(ltc2672_span_helper),
	.internal_vref_mv = 1250,
	.manual_span_support = false,
	.rfsadj_support = true,
};

static int ltc2664_set_span(const struct ltc2664_state *st, int min, int max,
			    int chan)
{
	const struct ltc2664_chip_info *chip_info = st->chip_info;
	const int (*span_helper)[2] = chip_info->span_helper;
	int span, ret;

	for (span = 0; span < chip_info->num_span; span++) {
		if (min == span_helper[span][0] && max == span_helper[span][1])
			break;
	}

	if (span == chip_info->num_span)
		return -EINVAL;

	ret = regmap_write(st->regmap, LTC2664_CMD_SPAN_N(chan), span);
	if (ret)
		return ret;

	return span;
}

static int ltc2664_channel_config(struct ltc2664_state *st)
{
	const struct ltc2664_chip_info *chip_info = st->chip_info;
	struct device *dev = &st->spi->dev;
	u32 reg, tmp[2], mspan;
	int ret;

	mspan = LTC2664_MSPAN_SOFTSPAN;
	ret = device_property_read_u32(dev, "adi,manual-span-operation-config",
				       &mspan);
	if (!ret) {
		if (!chip_info->manual_span_support)
			return dev_err_probe(dev, -EINVAL,
			       "adi,manual-span-operation-config not supported\n");

		if (mspan >= ARRAY_SIZE(ltc2664_mspan_lut))
			return dev_err_probe(dev, -EINVAL,
			       "adi,manual-span-operation-config not in range\n");
	}

	st->rfsadj_ohms = 20000;
	ret = device_property_read_u32(dev, "adi,rfsadj-ohms", &st->rfsadj_ohms);
	if (!ret) {
		if (!chip_info->rfsadj_support)
			return dev_err_probe(dev, -EINVAL,
					     "adi,rfsadj-ohms not supported\n");

		if (st->rfsadj_ohms < 19000 || st->rfsadj_ohms > 41000)
			return dev_err_probe(dev, -EINVAL,
					     "adi,rfsadj-ohms not in range\n");
	}

	device_for_each_child_node_scoped(dev, child) {
		struct ltc2664_chan *chan;

		ret = fwnode_property_read_u32(child, "reg", &reg);
		if (ret)
			return dev_err_probe(dev, ret,
					     "Failed to get reg property\n");

		if (reg >= chip_info->num_channels)
			return dev_err_probe(dev, -EINVAL,
					     "reg bigger than: %d\n",
					     chip_info->num_channels);

		chan = &st->channels[reg];

		if (fwnode_property_read_bool(child, "adi,toggle-mode")) {
			chan->toggle_chan = true;
			/* assume sw toggle ABI */
			st->iio_channels[reg].ext_info = ltc2664_toggle_sym_ext_info;

			/*
			 * Clear IIO_CHAN_INFO_RAW bit as toggle channels expose
			 * out_voltage/current_raw{0|1} files.
			 */
			__clear_bit(IIO_CHAN_INFO_RAW,
				    &st->iio_channels[reg].info_mask_separate);
		}

		chan->raw[0] = ltc2664_mspan_lut[mspan][1];
		chan->raw[1] = ltc2664_mspan_lut[mspan][1];

		chan->span = ltc2664_mspan_lut[mspan][0];

		ret = fwnode_property_read_u32_array(child, "output-range-microvolt",
						     tmp, ARRAY_SIZE(tmp));
		if (!ret && mspan == LTC2664_MSPAN_SOFTSPAN) {
			ret = ltc2664_set_span(st, tmp[0] / 1000, tmp[1] / 1000, reg);
			if (ret < 0)
				return dev_err_probe(dev, ret,
						     "Failed to set span\n");
			chan->span = ret;
		}

		ret = fwnode_property_read_u32_array(child, "output-range-microamp",
						     tmp, ARRAY_SIZE(tmp));
		if (!ret) {
			ret = ltc2664_set_span(st, 0, tmp[1] / 1000, reg);
			if (ret < 0)
				return dev_err_probe(dev, ret,
						     "Failed to set span\n");
			chan->span = ret;
		}
	}

	return 0;
}

static int ltc2664_setup(struct ltc2664_state *st)
{
	const struct ltc2664_chip_info *chip_info = st->chip_info;
	struct gpio_desc *gpio;
	int ret, i;

	/* If we have a clr/reset pin, use that to reset the chip. */
	gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(gpio))
		return dev_err_probe(&st->spi->dev, PTR_ERR(gpio),
				     "Failed to get reset gpio");
	if (gpio) {
		fsleep(1000);
		gpiod_set_value_cansleep(gpio, 0);
	}

	/*
	 * Duplicate the default channel configuration as it can change during
	 * @ltc2664_channel_config()
	 */
	st->iio_channels = devm_kcalloc(&st->spi->dev,
					chip_info->num_channels,
					sizeof(struct iio_chan_spec),
					GFP_KERNEL);
	if (!st->iio_channels)
		return -ENOMEM;

	for (i = 0; i < chip_info->num_channels; i++) {
		st->iio_channels[i] = ltc2664_channel_template;
		st->iio_channels[i].type = chip_info->measurement_type;
		st->iio_channels[i].channel = i;
	}

	ret = ltc2664_channel_config(st);
	if (ret)
		return ret;

	return regmap_set_bits(st->regmap, LTC2664_CMD_CONFIG, LTC2664_REF_DISABLE);
}

static const struct regmap_config ltc2664_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = LTC2664_CMD_NO_OPERATION,
};

static const struct iio_info ltc2664_info = {
	.write_raw = ltc2664_write_raw,
	.read_raw = ltc2664_read_raw,
	.read_avail = ltc2664_read_avail,
	.debugfs_reg_access = ltc2664_reg_access,
};

static int ltc2664_probe(struct spi_device *spi)
{
	static const char * const regulators[] = { "vcc", "iovcc", "v-neg" };
	const struct ltc2664_chip_info *chip_info;
	struct device *dev = &spi->dev;
	struct iio_dev *indio_dev;
	struct ltc2664_state *st;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	st->spi = spi;

	chip_info = spi_get_device_match_data(spi);
	if (!chip_info)
		return -ENODEV;

	st->chip_info = chip_info;

	mutex_init(&st->lock);

	st->regmap = devm_regmap_init_spi(spi, &ltc2664_regmap_config);
	if (IS_ERR(st->regmap))
		return dev_err_probe(dev, PTR_ERR(st->regmap),
				     "Failed to init regmap");

	ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(regulators),
					     regulators);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to enable regulators\n");

	ret = devm_regulator_get_enable_read_voltage(dev, "ref");
	if (ret < 0 && ret != -ENODEV)
		return ret;

	st->vref_mv = ret > 0 ? ret / 1000 :  chip_info->internal_vref_mv;

	ret = ltc2664_setup(st);
	if (ret)
		return ret;

	indio_dev->name = chip_info->name;
	indio_dev->info = &ltc2664_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = st->iio_channels;
	indio_dev->num_channels = chip_info->num_channels;

	return devm_iio_device_register(dev, indio_dev);
}

static const struct spi_device_id ltc2664_id[] = {
	{ "ltc2664", (kernel_ulong_t)&ltc2664_chip },
	{ "ltc2672", (kernel_ulong_t)&ltc2672_chip },
	{ }
};
MODULE_DEVICE_TABLE(spi, ltc2664_id);

static const struct of_device_id ltc2664_of_id[] = {
	{ .compatible = "adi,ltc2664", .data = &ltc2664_chip },
	{ .compatible = "adi,ltc2672", .data = &ltc2672_chip },
	{ }
};
MODULE_DEVICE_TABLE(of, ltc2664_of_id);

static struct spi_driver ltc2664_driver = {
	.driver = {
		.name = "ltc2664",
		.of_match_table = ltc2664_of_id,
	},
	.probe = ltc2664_probe,
	.id_table = ltc2664_id,
};
module_spi_driver(ltc2664_driver);

MODULE_AUTHOR("Michael Hennerich <[e-mail]>");
MODULE_AUTHOR("Kim Seer Paller <[e-mail]>");
MODULE_DESCRIPTION("Analog Devices LTC2664 and LTC2672 DAC");
MODULE_LICENSE("GPL");