drivers/iio/dac/ltc2632.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * LTC2632 Digital to analog convertors spi driver
  *
  * Copyright 2017 Maxime Roussin-Bélanger
  * expanded by Silvan Murer <silvan.murer@gmail.com>
  */

 #include <linux/device.h>
 #include <linux/spi/spi.h>
 #include <linux/module.h>
 #include <linux/iio/iio.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>

 #include <asm/unaligned.h>

 #define LTC2632_CMD_WRITE_INPUT_N               0x0
 #define LTC2632_CMD_UPDATE_DAC_N                0x1
 #define LTC2632_CMD_WRITE_INPUT_N_UPDATE_ALL    0x2
 #define LTC2632_CMD_WRITE_INPUT_N_UPDATE_N      0x3
 #define LTC2632_CMD_POWERDOWN_DAC_N             0x4
 #define LTC2632_CMD_POWERDOWN_CHIP              0x5
 #define LTC2632_CMD_INTERNAL_REFER              0x6
 #define LTC2632_CMD_EXTERNAL_REFER              0x7

 /**
  * struct ltc2632_chip_info - chip specific information
  * @channels:		channel spec for the DAC
  * @num_channels:	DAC channel count of the chip
  * @vref_mv:		internal reference voltage
  */
 struct ltc2632_chip_info {
 	const struct iio_chan_spec *channels;
 	const size_t num_channels;
 	const int vref_mv;
 };

 /**
  * struct ltc2632_state - driver instance specific data
  * @spi_dev:			pointer to the spi_device struct
  * @powerdown_cache_mask:	used to show current channel powerdown state
  * @vref_mv:			used reference voltage (internal or external)
  * @vref_reg:		regulator for the reference voltage
  */
 struct ltc2632_state {
 	struct spi_device *spi_dev;
 	unsigned int powerdown_cache_mask;
 	int vref_mv;
 	struct regulator *vref_reg;
 };

 enum ltc2632_supported_device_ids {
 	ID_LTC2632L12,
 	ID_LTC2632L10,
 	ID_LTC2632L8,
 	ID_LTC2632H12,
 	ID_LTC2632H10,
 	ID_LTC2632H8,
 	ID_LTC2634L12,
 	ID_LTC2634L10,
 	ID_LTC2634L8,
 	ID_LTC2634H12,
 	ID_LTC2634H10,
 	ID_LTC2634H8,
 	ID_LTC2636L12,
 	ID_LTC2636L10,
 	ID_LTC2636L8,
 	ID_LTC2636H12,
 	ID_LTC2636H10,
 	ID_LTC2636H8,
 };

 static int ltc2632_spi_write(struct spi_device *spi,
 			     u8 cmd, u8 addr, u16 val, u8 shift)
 {
 	u32 data;
 	u8 msg[3];

 	/*
 	 * The input shift register is 24 bits wide.
 	 * The next four are the command bits, C3 to C0,
 	 * followed by the 4-bit DAC address, A3 to A0, and then the
 	 * 12-, 10-, 8-bit data-word. The data-word comprises the 12-,
 	 * 10-, 8-bit input code followed by 4, 6, or 8 don't care bits.
 	 */
 	data = (cmd << 20) | (addr << 16) | (val << shift);
 	put_unaligned_be24(data, &msg[0]);

 	return spi_write(spi, msg, sizeof(msg));
 }

 static int ltc2632_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val,
 			    int *val2,
 			    long m)
 {
 	const struct ltc2632_state *st = iio_priv(indio_dev);

 	switch (m) {
 	case IIO_CHAN_INFO_SCALE:
 		*val = st->vref_mv;
 		*val2 = chan->scan_type.realbits;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	}
 	return -EINVAL;
 }

 static int ltc2632_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val,
 			     int val2,
 			     long mask)
 {
 	struct ltc2632_state *st = iio_priv(indio_dev);

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		if (val >= (1 << chan->scan_type.realbits) || val < 0)
 			return -EINVAL;

 		return ltc2632_spi_write(st->spi_dev,
 					 LTC2632_CMD_WRITE_INPUT_N_UPDATE_N,
 					 chan->address, val,
 					 chan->scan_type.shift);
 	default:
 		return -EINVAL;
 	}
 }

 static ssize_t ltc2632_read_dac_powerdown(struct iio_dev *indio_dev,
 					  uintptr_t private,
 					  const struct iio_chan_spec *chan,
 					  char *buf)
 {
 	struct ltc2632_state *st = iio_priv(indio_dev);

 	return sysfs_emit(buf, "%d\n",
 			  !!(st->powerdown_cache_mask & (1 << chan->channel)));
 }

 static ssize_t ltc2632_write_dac_powerdown(struct iio_dev *indio_dev,
 					   uintptr_t private,
 					   const struct iio_chan_spec *chan,
 					   const char *buf,
 					   size_t len)
 {
 	bool pwr_down;
 	int ret;
 	struct ltc2632_state *st = iio_priv(indio_dev);

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

 	if (pwr_down)
 		st->powerdown_cache_mask |= (1 << chan->channel);
 	else
 		st->powerdown_cache_mask &= ~(1 << chan->channel);

 	ret = ltc2632_spi_write(st->spi_dev,
 				LTC2632_CMD_POWERDOWN_DAC_N,
 				chan->channel, 0, 0);

 	return ret ? ret : len;
 }

 static const struct iio_info ltc2632_info = {
 	.write_raw	= ltc2632_write_raw,
 	.read_raw	= ltc2632_read_raw,
 };

 static const struct iio_chan_spec_ext_info ltc2632_ext_info[] = {
 	{
 		.name = "powerdown",
 		.read = ltc2632_read_dac_powerdown,
 		.write = ltc2632_write_dac_powerdown,
 		.shared = IIO_SEPARATE,
 	},
 	{ },
 };

 #define LTC2632_CHANNEL(_chan, _bits) { \
 		.type = IIO_VOLTAGE, \
 		.indexed = 1, \
 		.output = 1, \
 		.channel = (_chan), \
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 		.address = (_chan), \
 		.scan_type = { \
 			.realbits	= (_bits), \
 			.shift		= 16 - (_bits), \
 		}, \
 		.ext_info = ltc2632_ext_info, \
 }

 #define DECLARE_LTC2632_CHANNELS(_name, _bits) \
 	const struct iio_chan_spec _name ## _channels[] = { \
 		LTC2632_CHANNEL(0, _bits), \
 		LTC2632_CHANNEL(1, _bits), \
 		LTC2632_CHANNEL(2, _bits), \
 		LTC2632_CHANNEL(3, _bits), \
 		LTC2632_CHANNEL(4, _bits), \
 		LTC2632_CHANNEL(5, _bits), \
 		LTC2632_CHANNEL(6, _bits), \
 		LTC2632_CHANNEL(7, _bits), \
 	}

 static DECLARE_LTC2632_CHANNELS(ltc2632x12, 12);
 static DECLARE_LTC2632_CHANNELS(ltc2632x10, 10);
 static DECLARE_LTC2632_CHANNELS(ltc2632x8, 8);

 static const struct ltc2632_chip_info ltc2632_chip_info_tbl[] = {
 	[ID_LTC2632L12] = {
 		.channels	= ltc2632x12_channels,
 		.num_channels	= 2,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2632L10] = {
 		.channels	= ltc2632x10_channels,
 		.num_channels	= 2,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2632L8] =  {
 		.channels	= ltc2632x8_channels,
 		.num_channels	= 2,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2632H12] = {
 		.channels	= ltc2632x12_channels,
 		.num_channels	= 2,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2632H10] = {
 		.channels	= ltc2632x10_channels,
 		.num_channels	= 2,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2632H8] =  {
 		.channels	= ltc2632x8_channels,
 		.num_channels	= 2,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2634L12] = {
 		.channels	= ltc2632x12_channels,
 		.num_channels	= 4,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2634L10] = {
 		.channels	= ltc2632x10_channels,
 		.num_channels	= 4,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2634L8] =  {
 		.channels	= ltc2632x8_channels,
 		.num_channels	= 4,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2634H12] = {
 		.channels	= ltc2632x12_channels,
 		.num_channels	= 4,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2634H10] = {
 		.channels	= ltc2632x10_channels,
 		.num_channels	= 4,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2634H8] =  {
 		.channels	= ltc2632x8_channels,
 		.num_channels	= 4,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2636L12] = {
 		.channels	= ltc2632x12_channels,
 		.num_channels	= 8,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2636L10] = {
 		.channels	= ltc2632x10_channels,
 		.num_channels	= 8,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2636L8] =  {
 		.channels	= ltc2632x8_channels,
 		.num_channels	= 8,
 		.vref_mv	= 2500,
 	},
 	[ID_LTC2636H12] = {
 		.channels	= ltc2632x12_channels,
 		.num_channels	= 8,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2636H10] = {
 		.channels	= ltc2632x10_channels,
 		.num_channels	= 8,
 		.vref_mv	= 4096,
 	},
 	[ID_LTC2636H8] =  {
 		.channels	= ltc2632x8_channels,
 		.num_channels	= 8,
 		.vref_mv	= 4096,
 	},
 };

 static int ltc2632_probe(struct spi_device *spi)
 {
 	struct ltc2632_state *st;
 	struct iio_dev *indio_dev;
 	struct ltc2632_chip_info *chip_info;
 	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_dev = spi;

 	chip_info = (struct ltc2632_chip_info *)
 			spi_get_device_id(spi)->driver_data;

 	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
 	if (PTR_ERR(st->vref_reg) == -ENODEV) {
 		/* use internal reference voltage */
 		st->vref_reg = NULL;
 		st->vref_mv = chip_info->vref_mv;

 		ret = ltc2632_spi_write(spi, LTC2632_CMD_INTERNAL_REFER,
 				0, 0, 0);
 		if (ret) {
 			dev_err(&spi->dev,
 				"Set internal reference command failed, %d\n",
 				ret);
 			return ret;
 		}
 	} else if (IS_ERR(st->vref_reg)) {
 		dev_err(&spi->dev,
 				"Error getting voltage reference regulator\n");
 		return PTR_ERR(st->vref_reg);
 	} else {
 		/* use external reference voltage */
 		ret = regulator_enable(st->vref_reg);
 		if (ret) {
 			dev_err(&spi->dev,
 				"enable reference regulator failed, %d\n",
 				ret);
 			return ret;
 		}
 		st->vref_mv = regulator_get_voltage(st->vref_reg) / 1000;

 		ret = ltc2632_spi_write(spi, LTC2632_CMD_EXTERNAL_REFER,
 				0, 0, 0);
 		if (ret) {
 			dev_err(&spi->dev,
 				"Set external reference command failed, %d\n",
 				ret);
 			return ret;
 		}
 	}

 	indio_dev->name = fwnode_get_name(dev_fwnode(&spi->dev)) ?: spi_get_device_id(spi)->name;
 	indio_dev->info = &ltc2632_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = chip_info->channels;
 	indio_dev->num_channels = chip_info->num_channels;

 	return iio_device_register(indio_dev);
 }

 static void ltc2632_remove(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
 	struct ltc2632_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);

 	if (st->vref_reg)
 		regulator_disable(st->vref_reg);
 }

 static const struct spi_device_id ltc2632_id[] = {
 	{ "ltc2632-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L12] },
 	{ "ltc2632-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L10] },
 	{ "ltc2632-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L8] },
 	{ "ltc2632-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H12] },
 	{ "ltc2632-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H10] },
 	{ "ltc2632-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H8] },
 	{ "ltc2634-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L12] },
 	{ "ltc2634-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L10] },
 	{ "ltc2634-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L8] },
 	{ "ltc2634-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H12] },
 	{ "ltc2634-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H10] },
 	{ "ltc2634-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H8] },
 	{ "ltc2636-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L12] },
 	{ "ltc2636-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L10] },
 	{ "ltc2636-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L8] },
 	{ "ltc2636-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H12] },
 	{ "ltc2636-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H10] },
 	{ "ltc2636-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H8] },
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ltc2632_id);

 static const struct of_device_id ltc2632_of_match[] = {
 	{
 		.compatible = "lltc,ltc2632-l12",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2632L12]
 	}, {
 		.compatible = "lltc,ltc2632-l10",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2632L10]
 	}, {
 		.compatible = "lltc,ltc2632-l8",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2632L8]
 	}, {
 		.compatible = "lltc,ltc2632-h12",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2632H12]
 	}, {
 		.compatible = "lltc,ltc2632-h10",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2632H10]
 	}, {
 		.compatible = "lltc,ltc2632-h8",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2632H8]
 	}, {
 		.compatible = "lltc,ltc2634-l12",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2634L12]
 	}, {
 		.compatible = "lltc,ltc2634-l10",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2634L10]
 	}, {
 		.compatible = "lltc,ltc2634-l8",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2634L8]
 	}, {
 		.compatible = "lltc,ltc2634-h12",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2634H12]
 	}, {
 		.compatible = "lltc,ltc2634-h10",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2634H10]
 	}, {
 		.compatible = "lltc,ltc2634-h8",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2634H8]
 	}, {
 		.compatible = "lltc,ltc2636-l12",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2636L12]
 	}, {
 		.compatible = "lltc,ltc2636-l10",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2636L10]
 	}, {
 		.compatible = "lltc,ltc2636-l8",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2636L8]
 	}, {
 		.compatible = "lltc,ltc2636-h12",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2636H12]
 	}, {
 		.compatible = "lltc,ltc2636-h10",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2636H10]
 	}, {
 		.compatible = "lltc,ltc2636-h8",
 		.data = &ltc2632_chip_info_tbl[ID_LTC2636H8]
 	},
 	{}
 };
 MODULE_DEVICE_TABLE(of, ltc2632_of_match);

 static struct spi_driver ltc2632_driver = {
 	.driver		= {
 		.name	= "ltc2632",
 		.of_match_table = ltc2632_of_match,
 	},
 	.probe		= ltc2632_probe,
 	.remove		= ltc2632_remove,
 	.id_table	= ltc2632_id,
 };
 module_spi_driver(ltc2632_driver);

 MODULE_AUTHOR("Maxime Roussin-Belanger <maxime.roussinbelanger@gmail.com>");
 MODULE_DESCRIPTION("LTC2632 DAC SPI driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* LTC2632 Digital to analog convertors spi driver
	*
	* Copyright 2017 Maxime Roussin-Bélanger
	* expanded by Silvan Murer <silvan.murer@gmail.com>
	*/

	#include <linux/device.h>
	#include <linux/spi/spi.h>
	#include <linux/module.h>
	#include <linux/iio/iio.h>
	#include <linux/property.h>
	#include <linux/regulator/consumer.h>

	#include <asm/unaligned.h>

	#define LTC2632_CMD_WRITE_INPUT_N 0x0
	#define LTC2632_CMD_UPDATE_DAC_N 0x1
	#define LTC2632_CMD_WRITE_INPUT_N_UPDATE_ALL 0x2
	#define LTC2632_CMD_WRITE_INPUT_N_UPDATE_N 0x3
	#define LTC2632_CMD_POWERDOWN_DAC_N 0x4
	#define LTC2632_CMD_POWERDOWN_CHIP 0x5
	#define LTC2632_CMD_INTERNAL_REFER 0x6
	#define LTC2632_CMD_EXTERNAL_REFER 0x7

	/**
	* struct ltc2632_chip_info - chip specific information
	* @channels: channel spec for the DAC
	* @num_channels: DAC channel count of the chip
	* @vref_mv: internal reference voltage
	*/
	struct ltc2632_chip_info {
	const struct iio_chan_spec *channels;
	const size_t num_channels;
	const int vref_mv;
	};

	/**
	* struct ltc2632_state - driver instance specific data
	* @spi_dev: pointer to the spi_device struct
	* @powerdown_cache_mask: used to show current channel powerdown state
	* @vref_mv: used reference voltage (internal or external)
	* @vref_reg: regulator for the reference voltage
	*/
	struct ltc2632_state {
	struct spi_device *spi_dev;
	unsigned int powerdown_cache_mask;
	int vref_mv;
	struct regulator *vref_reg;
	};

	enum ltc2632_supported_device_ids {
	ID_LTC2632L12,
	ID_LTC2632L10,
	ID_LTC2632L8,
	ID_LTC2632H12,
	ID_LTC2632H10,
	ID_LTC2632H8,
	ID_LTC2634L12,
	ID_LTC2634L10,
	ID_LTC2634L8,
	ID_LTC2634H12,
	ID_LTC2634H10,
	ID_LTC2634H8,
	ID_LTC2636L12,
	ID_LTC2636L10,
	ID_LTC2636L8,
	ID_LTC2636H12,
	ID_LTC2636H10,
	ID_LTC2636H8,
	};

	static int ltc2632_spi_write(struct spi_device *spi,
	u8 cmd, u8 addr, u16 val, u8 shift)
	{
	u32 data;
	u8 msg[3];

	/*
	* The input shift register is 24 bits wide.
	* The next four are the command bits, C3 to C0,
	* followed by the 4-bit DAC address, A3 to A0, and then the
	* 12-, 10-, 8-bit data-word. The data-word comprises the 12-,
	* 10-, 8-bit input code followed by 4, 6, or 8 don't care bits.
	*/
	data = (cmd << 20) \| (addr << 16) \| (val << shift);
	put_unaligned_be24(data, &msg[0]);

	return spi_write(spi, msg, sizeof(msg));
	}

	static int ltc2632_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int *val,
	int *val2,
	long m)
	{
	const struct ltc2632_state *st = iio_priv(indio_dev);

	switch (m) {
	case IIO_CHAN_INFO_SCALE:
	*val = st->vref_mv;
	*val2 = chan->scan_type.realbits;
	return IIO_VAL_FRACTIONAL_LOG2;
	}
	return -EINVAL;
	}

	static int ltc2632_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val,
	int val2,
	long mask)
	{
	struct ltc2632_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	if (val >= (1 << chan->scan_type.realbits) \|\| val < 0)
	return -EINVAL;

	return ltc2632_spi_write(st->spi_dev,
	LTC2632_CMD_WRITE_INPUT_N_UPDATE_N,
	chan->address, val,
	chan->scan_type.shift);
	default:
	return -EINVAL;
	}
	}

	static ssize_t ltc2632_read_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private,
	const struct iio_chan_spec *chan,
	char *buf)
	{
	struct ltc2632_state *st = iio_priv(indio_dev);

	return sysfs_emit(buf, "%d\n",
	!!(st->powerdown_cache_mask & (1 << chan->channel)));
	}

	static ssize_t ltc2632_write_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private,
	const struct iio_chan_spec *chan,
	const char *buf,
	size_t len)
	{
	bool pwr_down;
	int ret;
	struct ltc2632_state *st = iio_priv(indio_dev);

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

	if (pwr_down)
	st->powerdown_cache_mask \|= (1 << chan->channel);
	else
	st->powerdown_cache_mask &= ~(1 << chan->channel);

	ret = ltc2632_spi_write(st->spi_dev,
	LTC2632_CMD_POWERDOWN_DAC_N,
	chan->channel, 0, 0);

	return ret ? ret : len;
	}

	static const struct iio_info ltc2632_info = {
	.write_raw = ltc2632_write_raw,
	.read_raw = ltc2632_read_raw,
	};

	static const struct iio_chan_spec_ext_info ltc2632_ext_info[] = {
	{
	.name = "powerdown",
	.read = ltc2632_read_dac_powerdown,
	.write = ltc2632_write_dac_powerdown,
	.shared = IIO_SEPARATE,
	},
	{ },
	};

	#define LTC2632_CHANNEL(_chan, _bits) { \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.output = 1, \
	.channel = (_chan), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.address = (_chan), \
	.scan_type = { \
	.realbits = (_bits), \
	.shift = 16 - (_bits), \
	}, \
	.ext_info = ltc2632_ext_info, \
	}

	#define DECLARE_LTC2632_CHANNELS(_name, _bits) \
	const struct iio_chan_spec _name ## _channels[] = { \
	LTC2632_CHANNEL(0, _bits), \
	LTC2632_CHANNEL(1, _bits), \
	LTC2632_CHANNEL(2, _bits), \
	LTC2632_CHANNEL(3, _bits), \
	LTC2632_CHANNEL(4, _bits), \
	LTC2632_CHANNEL(5, _bits), \
	LTC2632_CHANNEL(6, _bits), \
	LTC2632_CHANNEL(7, _bits), \
	}

	static DECLARE_LTC2632_CHANNELS(ltc2632x12, 12);
	static DECLARE_LTC2632_CHANNELS(ltc2632x10, 10);
	static DECLARE_LTC2632_CHANNELS(ltc2632x8, 8);

	static const struct ltc2632_chip_info ltc2632_chip_info_tbl[] = {
	[ID_LTC2632L12] = {
	.channels = ltc2632x12_channels,
	.num_channels = 2,
	.vref_mv = 2500,
	},
	[ID_LTC2632L10] = {
	.channels = ltc2632x10_channels,
	.num_channels = 2,
	.vref_mv = 2500,
	},
	[ID_LTC2632L8] = {
	.channels = ltc2632x8_channels,
	.num_channels = 2,
	.vref_mv = 2500,
	},
	[ID_LTC2632H12] = {
	.channels = ltc2632x12_channels,
	.num_channels = 2,
	.vref_mv = 4096,
	},
	[ID_LTC2632H10] = {
	.channels = ltc2632x10_channels,
	.num_channels = 2,
	.vref_mv = 4096,
	},
	[ID_LTC2632H8] = {
	.channels = ltc2632x8_channels,
	.num_channels = 2,
	.vref_mv = 4096,
	},
	[ID_LTC2634L12] = {
	.channels = ltc2632x12_channels,
	.num_channels = 4,
	.vref_mv = 2500,
	},
	[ID_LTC2634L10] = {
	.channels = ltc2632x10_channels,
	.num_channels = 4,
	.vref_mv = 2500,
	},
	[ID_LTC2634L8] = {
	.channels = ltc2632x8_channels,
	.num_channels = 4,
	.vref_mv = 2500,
	},
	[ID_LTC2634H12] = {
	.channels = ltc2632x12_channels,
	.num_channels = 4,
	.vref_mv = 4096,
	},
	[ID_LTC2634H10] = {
	.channels = ltc2632x10_channels,
	.num_channels = 4,
	.vref_mv = 4096,
	},
	[ID_LTC2634H8] = {
	.channels = ltc2632x8_channels,
	.num_channels = 4,
	.vref_mv = 4096,
	},
	[ID_LTC2636L12] = {
	.channels = ltc2632x12_channels,
	.num_channels = 8,
	.vref_mv = 2500,
	},
	[ID_LTC2636L10] = {
	.channels = ltc2632x10_channels,
	.num_channels = 8,
	.vref_mv = 2500,
	},
	[ID_LTC2636L8] = {
	.channels = ltc2632x8_channels,
	.num_channels = 8,
	.vref_mv = 2500,
	},
	[ID_LTC2636H12] = {
	.channels = ltc2632x12_channels,
	.num_channels = 8,
	.vref_mv = 4096,
	},
	[ID_LTC2636H10] = {
	.channels = ltc2632x10_channels,
	.num_channels = 8,
	.vref_mv = 4096,
	},
	[ID_LTC2636H8] = {
	.channels = ltc2632x8_channels,
	.num_channels = 8,
	.vref_mv = 4096,
	},
	};

	static int ltc2632_probe(struct spi_device *spi)
	{
	struct ltc2632_state *st;
	struct iio_dev *indio_dev;
	struct ltc2632_chip_info *chip_info;
	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_dev = spi;

	chip_info = (struct ltc2632_chip_info *)
	spi_get_device_id(spi)->driver_data;

	st->vref_reg = devm_regulator_get_optional(&spi->dev, "vref");
	if (PTR_ERR(st->vref_reg) == -ENODEV) {
	/* use internal reference voltage */
	st->vref_reg = NULL;
	st->vref_mv = chip_info->vref_mv;

	ret = ltc2632_spi_write(spi, LTC2632_CMD_INTERNAL_REFER,
	0, 0, 0);
	if (ret) {
	dev_err(&spi->dev,
	"Set internal reference command failed, %d\n",
	ret);
	return ret;
	}
	} else if (IS_ERR(st->vref_reg)) {
	dev_err(&spi->dev,
	"Error getting voltage reference regulator\n");
	return PTR_ERR(st->vref_reg);
	} else {
	/* use external reference voltage */
	ret = regulator_enable(st->vref_reg);
	if (ret) {
	dev_err(&spi->dev,
	"enable reference regulator failed, %d\n",
	ret);
	return ret;
	}
	st->vref_mv = regulator_get_voltage(st->vref_reg) / 1000;

	ret = ltc2632_spi_write(spi, LTC2632_CMD_EXTERNAL_REFER,
	0, 0, 0);
	if (ret) {
	dev_err(&spi->dev,
	"Set external reference command failed, %d\n",
	ret);
	return ret;
	}
	}

	indio_dev->name = fwnode_get_name(dev_fwnode(&spi->dev)) ?: spi_get_device_id(spi)->name;
	indio_dev->info = &ltc2632_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = chip_info->channels;
	indio_dev->num_channels = chip_info->num_channels;

	return iio_device_register(indio_dev);
	}

	static void ltc2632_remove(struct spi_device *spi)
	{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct ltc2632_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	if (st->vref_reg)
	regulator_disable(st->vref_reg);
	}

	static const struct spi_device_id ltc2632_id[] = {
	{ "ltc2632-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L12] },
	{ "ltc2632-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L10] },
	{ "ltc2632-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632L8] },
	{ "ltc2632-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H12] },
	{ "ltc2632-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H10] },
	{ "ltc2632-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2632H8] },
	{ "ltc2634-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L12] },
	{ "ltc2634-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L10] },
	{ "ltc2634-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634L8] },
	{ "ltc2634-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H12] },
	{ "ltc2634-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H10] },
	{ "ltc2634-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2634H8] },
	{ "ltc2636-l12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L12] },
	{ "ltc2636-l10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L10] },
	{ "ltc2636-l8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636L8] },
	{ "ltc2636-h12", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H12] },
	{ "ltc2636-h10", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H10] },
	{ "ltc2636-h8", (kernel_ulong_t)&ltc2632_chip_info_tbl[ID_LTC2636H8] },
	{}
	};
	MODULE_DEVICE_TABLE(spi, ltc2632_id);

	static const struct of_device_id ltc2632_of_match[] = {
	{
	.compatible = "lltc,ltc2632-l12",
	.data = &ltc2632_chip_info_tbl[ID_LTC2632L12]
	}, {
	.compatible = "lltc,ltc2632-l10",
	.data = &ltc2632_chip_info_tbl[ID_LTC2632L10]
	}, {
	.compatible = "lltc,ltc2632-l8",
	.data = &ltc2632_chip_info_tbl[ID_LTC2632L8]
	}, {
	.compatible = "lltc,ltc2632-h12",
	.data = &ltc2632_chip_info_tbl[ID_LTC2632H12]
	}, {
	.compatible = "lltc,ltc2632-h10",
	.data = &ltc2632_chip_info_tbl[ID_LTC2632H10]
	}, {
	.compatible = "lltc,ltc2632-h8",
	.data = &ltc2632_chip_info_tbl[ID_LTC2632H8]
	}, {
	.compatible = "lltc,ltc2634-l12",
	.data = &ltc2632_chip_info_tbl[ID_LTC2634L12]
	}, {
	.compatible = "lltc,ltc2634-l10",
	.data = &ltc2632_chip_info_tbl[ID_LTC2634L10]
	}, {
	.compatible = "lltc,ltc2634-l8",
	.data = &ltc2632_chip_info_tbl[ID_LTC2634L8]
	}, {
	.compatible = "lltc,ltc2634-h12",
	.data = &ltc2632_chip_info_tbl[ID_LTC2634H12]
	}, {
	.compatible = "lltc,ltc2634-h10",
	.data = &ltc2632_chip_info_tbl[ID_LTC2634H10]
	}, {
	.compatible = "lltc,ltc2634-h8",
	.data = &ltc2632_chip_info_tbl[ID_LTC2634H8]
	}, {
	.compatible = "lltc,ltc2636-l12",
	.data = &ltc2632_chip_info_tbl[ID_LTC2636L12]
	}, {
	.compatible = "lltc,ltc2636-l10",
	.data = &ltc2632_chip_info_tbl[ID_LTC2636L10]
	}, {
	.compatible = "lltc,ltc2636-l8",
	.data = &ltc2632_chip_info_tbl[ID_LTC2636L8]
	}, {
	.compatible = "lltc,ltc2636-h12",
	.data = &ltc2632_chip_info_tbl[ID_LTC2636H12]
	}, {
	.compatible = "lltc,ltc2636-h10",
	.data = &ltc2632_chip_info_tbl[ID_LTC2636H10]
	}, {
	.compatible = "lltc,ltc2636-h8",
	.data = &ltc2632_chip_info_tbl[ID_LTC2636H8]
	},
	{}
	};
	MODULE_DEVICE_TABLE(of, ltc2632_of_match);

	static struct spi_driver ltc2632_driver = {
	.driver = {
	.name = "ltc2632",
	.of_match_table = ltc2632_of_match,
	},
	.probe = ltc2632_probe,
	.remove = ltc2632_remove,
	.id_table = ltc2632_id,
	};
	module_spi_driver(ltc2632_driver);

	MODULE_AUTHOR("Maxime Roussin-Belanger <maxime.roussinbelanger@gmail.com>");
	MODULE_DESCRIPTION("LTC2632 DAC SPI driver");
	MODULE_LICENSE("GPL v2");