drivers/iio/dac/ad5446.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * AD5446 SPI DAC driver
  *
  * Copyright 2010 Analog Devices Inc.
  */

 #include <linux/interrupt.h>
 #include <linux/workqueue.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/list.h>
 #include <linux/spi/spi.h>
 #include <linux/i2c.h>
 #include <linux/regulator/consumer.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>

 #include <asm/unaligned.h>

 #define MODE_PWRDWN_1k		0x1
 #define MODE_PWRDWN_100k	0x2
 #define MODE_PWRDWN_TRISTATE	0x3

 /**
  * struct ad5446_state - driver instance specific data
  * @dev:		this device
  * @chip_info:		chip model specific constants, available modes etc
  * @reg:		supply regulator
  * @vref_mv:		actual reference voltage used
  * @cached_val:		store/retrieve values during power down
  * @pwr_down_mode:	power down mode (1k, 100k or tristate)
  * @pwr_down:		true if the device is in power down
  * @lock:		lock to protect the data buffer during write ops
  */

 struct ad5446_state {
 	struct device		*dev;
 	const struct ad5446_chip_info	*chip_info;
 	struct regulator		*reg;
 	unsigned short			vref_mv;
 	unsigned			cached_val;
 	unsigned			pwr_down_mode;
 	unsigned			pwr_down;
 	struct mutex			lock;
 };

 /**
  * struct ad5446_chip_info - chip specific information
  * @channel:		channel spec for the DAC
  * @int_vref_mv:	AD5620/40/60: the internal reference voltage
  * @write:		chip specific helper function to write to the register
  */

 struct ad5446_chip_info {
 	struct iio_chan_spec	channel;
 	u16			int_vref_mv;
 	int			(*write)(struct ad5446_state *st, unsigned val);
 };

 static const char * const ad5446_powerdown_modes[] = {
 	"1kohm_to_gnd", "100kohm_to_gnd", "three_state"
 };

 static int ad5446_set_powerdown_mode(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan, unsigned int mode)
 {
 	struct ad5446_state *st = iio_priv(indio_dev);

 	st->pwr_down_mode = mode + 1;

 	return 0;
 }

 static int ad5446_get_powerdown_mode(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan)
 {
 	struct ad5446_state *st = iio_priv(indio_dev);

 	return st->pwr_down_mode - 1;
 }

 static const struct iio_enum ad5446_powerdown_mode_enum = {
 	.items = ad5446_powerdown_modes,
 	.num_items = ARRAY_SIZE(ad5446_powerdown_modes),
 	.get = ad5446_get_powerdown_mode,
 	.set = ad5446_set_powerdown_mode,
 };

 static ssize_t ad5446_read_dac_powerdown(struct iio_dev *indio_dev,
 					   uintptr_t private,
 					   const struct iio_chan_spec *chan,
 					   char *buf)
 {
 	struct ad5446_state *st = iio_priv(indio_dev);

 	return sprintf(buf, "%d\n", st->pwr_down);
 }

 static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
 					    uintptr_t private,
 					    const struct iio_chan_spec *chan,
 					    const char *buf, size_t len)
 {
 	struct ad5446_state *st = iio_priv(indio_dev);
 	unsigned int shift;
 	unsigned int val;
 	bool powerdown;
 	int ret;

 	ret = strtobool(buf, &powerdown);
 	if (ret)
 		return ret;

 	mutex_lock(&st->lock);
 	st->pwr_down = powerdown;

 	if (st->pwr_down) {
 		shift = chan->scan_type.realbits + chan->scan_type.shift;
 		val = st->pwr_down_mode << shift;
 	} else {
 		val = st->cached_val;
 	}

 	ret = st->chip_info->write(st, val);
 	mutex_unlock(&st->lock);

 	return ret ? ret : len;
 }

 static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
 	{
 		.name = "powerdown",
 		.read = ad5446_read_dac_powerdown,
 		.write = ad5446_write_dac_powerdown,
 		.shared = IIO_SEPARATE,
 	},
 	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
 	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5446_powerdown_mode_enum),
 	{ },
 };

 #define _AD5446_CHANNEL(bits, storage, _shift, ext) { \
 	.type = IIO_VOLTAGE, \
 	.indexed = 1, \
 	.output = 1, \
 	.channel = 0, \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = (bits), \
 		.storagebits = (storage), \
 		.shift = (_shift), \
 		}, \
 	.ext_info = (ext), \
 }

 #define AD5446_CHANNEL(bits, storage, shift) \
 	_AD5446_CHANNEL(bits, storage, shift, NULL)

 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
 	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)

 static int ad5446_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val,
 			   int *val2,
 			   long m)
 {
 	struct ad5446_state *st = iio_priv(indio_dev);

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

 static int ad5446_write_raw(struct iio_dev *indio_dev,
 			       struct iio_chan_spec const *chan,
 			       int val,
 			       int val2,
 			       long mask)
 {
 	struct ad5446_state *st = iio_priv(indio_dev);
 	int ret = 0;

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

 		val <<= chan->scan_type.shift;
 		mutex_lock(&st->lock);
 		st->cached_val = val;
 		if (!st->pwr_down)
 			ret = st->chip_info->write(st, val);
 		mutex_unlock(&st->lock);
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static const struct iio_info ad5446_info = {
 	.read_raw = ad5446_read_raw,
 	.write_raw = ad5446_write_raw,
 };

 static int ad5446_probe(struct device *dev, const char *name,
 			const struct ad5446_chip_info *chip_info)
 {
 	struct ad5446_state *st;
 	struct iio_dev *indio_dev;
 	struct regulator *reg;
 	int ret, voltage_uv = 0;

 	reg = devm_regulator_get(dev, "vcc");
 	if (!IS_ERR(reg)) {
 		ret = regulator_enable(reg);
 		if (ret)
 			return ret;

 		ret = regulator_get_voltage(reg);
 		if (ret < 0)
 			goto error_disable_reg;

 		voltage_uv = ret;
 	}

 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (indio_dev == NULL) {
 		ret = -ENOMEM;
 		goto error_disable_reg;
 	}
 	st = iio_priv(indio_dev);
 	st->chip_info = chip_info;

 	dev_set_drvdata(dev, indio_dev);
 	st->reg = reg;
 	st->dev = dev;

 	indio_dev->name = name;
 	indio_dev->info = &ad5446_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = &st->chip_info->channel;
 	indio_dev->num_channels = 1;

 	mutex_init(&st->lock);

 	st->pwr_down_mode = MODE_PWRDWN_1k;

 	if (st->chip_info->int_vref_mv)
 		st->vref_mv = st->chip_info->int_vref_mv;
 	else if (voltage_uv)
 		st->vref_mv = voltage_uv / 1000;
 	else
 		dev_warn(dev, "reference voltage unspecified\n");

 	ret = iio_device_register(indio_dev);
 	if (ret)
 		goto error_disable_reg;

 	return 0;

 error_disable_reg:
 	if (!IS_ERR(reg))
 		regulator_disable(reg);
 	return ret;
 }

 static int ad5446_remove(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct ad5446_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);

 	return 0;
 }

 #if IS_ENABLED(CONFIG_SPI_MASTER)

 static int ad5446_write(struct ad5446_state *st, unsigned val)
 {
 	struct spi_device *spi = to_spi_device(st->dev);
 	__be16 data = cpu_to_be16(val);

 	return spi_write(spi, &data, sizeof(data));
 }

 static int ad5660_write(struct ad5446_state *st, unsigned val)
 {
 	struct spi_device *spi = to_spi_device(st->dev);
 	uint8_t data[3];

 	put_unaligned_be24(val, &data[0]);

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

 /*
  * ad5446_supported_spi_device_ids:
  * The AD5620/40/60 parts are available in different fixed internal reference
  * voltage options. The actual part numbers may look differently
  * (and a bit cryptic), however this style is used to make clear which
  * parts are supported here.
  */
 enum ad5446_supported_spi_device_ids {
 	ID_AD5300,
 	ID_AD5310,
 	ID_AD5320,
 	ID_AD5444,
 	ID_AD5446,
 	ID_AD5450,
 	ID_AD5451,
 	ID_AD5541A,
 	ID_AD5512A,
 	ID_AD5553,
 	ID_AD5600,
 	ID_AD5601,
 	ID_AD5611,
 	ID_AD5621,
 	ID_AD5641,
 	ID_AD5620_2500,
 	ID_AD5620_1250,
 	ID_AD5640_2500,
 	ID_AD5640_1250,
 	ID_AD5660_2500,
 	ID_AD5660_1250,
 	ID_AD5662,
 };

 static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
 	[ID_AD5300] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
 		.write = ad5446_write,
 	},
 	[ID_AD5310] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
 		.write = ad5446_write,
 	},
 	[ID_AD5320] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
 		.write = ad5446_write,
 	},
 	[ID_AD5444] = {
 		.channel = AD5446_CHANNEL(12, 16, 2),
 		.write = ad5446_write,
 	},
 	[ID_AD5446] = {
 		.channel = AD5446_CHANNEL(14, 16, 0),
 		.write = ad5446_write,
 	},
 	[ID_AD5450] = {
 		.channel = AD5446_CHANNEL(8, 16, 6),
 		.write = ad5446_write,
 	},
 	[ID_AD5451] = {
 		.channel = AD5446_CHANNEL(10, 16, 4),
 		.write = ad5446_write,
 	},
 	[ID_AD5541A] = {
 		.channel = AD5446_CHANNEL(16, 16, 0),
 		.write = ad5446_write,
 	},
 	[ID_AD5512A] = {
 		.channel = AD5446_CHANNEL(12, 16, 4),
 		.write = ad5446_write,
 	},
 	[ID_AD5553] = {
 		.channel = AD5446_CHANNEL(14, 16, 0),
 		.write = ad5446_write,
 	},
 	[ID_AD5600] = {
 		.channel = AD5446_CHANNEL(16, 16, 0),
 		.write = ad5446_write,
 	},
 	[ID_AD5601] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
 		.write = ad5446_write,
 	},
 	[ID_AD5611] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
 		.write = ad5446_write,
 	},
 	[ID_AD5621] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
 		.write = ad5446_write,
 	},
 	[ID_AD5641] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
 		.write = ad5446_write,
 	},
 	[ID_AD5620_2500] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
 		.int_vref_mv = 2500,
 		.write = ad5446_write,
 	},
 	[ID_AD5620_1250] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
 		.int_vref_mv = 1250,
 		.write = ad5446_write,
 	},
 	[ID_AD5640_2500] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
 		.int_vref_mv = 2500,
 		.write = ad5446_write,
 	},
 	[ID_AD5640_1250] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
 		.int_vref_mv = 1250,
 		.write = ad5446_write,
 	},
 	[ID_AD5660_2500] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
 		.int_vref_mv = 2500,
 		.write = ad5660_write,
 	},
 	[ID_AD5660_1250] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
 		.int_vref_mv = 1250,
 		.write = ad5660_write,
 	},
 	[ID_AD5662] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
 		.write = ad5660_write,
 	},
 };

 static const struct spi_device_id ad5446_spi_ids[] = {
 	{"ad5300", ID_AD5300},
 	{"ad5310", ID_AD5310},
 	{"ad5320", ID_AD5320},
 	{"ad5444", ID_AD5444},
 	{"ad5446", ID_AD5446},
 	{"ad5450", ID_AD5450},
 	{"ad5451", ID_AD5451},
 	{"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
 	{"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
 	{"ad5512a", ID_AD5512A},
 	{"ad5541a", ID_AD5541A},
 	{"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
 	{"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
 	{"ad5553", ID_AD5553},
 	{"ad5600", ID_AD5600},
 	{"ad5601", ID_AD5601},
 	{"ad5611", ID_AD5611},
 	{"ad5621", ID_AD5621},
 	{"ad5641", ID_AD5641},
 	{"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
 	{"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
 	{"ad5640-2500", ID_AD5640_2500},
 	{"ad5640-1250", ID_AD5640_1250},
 	{"ad5660-2500", ID_AD5660_2500},
 	{"ad5660-1250", ID_AD5660_1250},
 	{"ad5662", ID_AD5662},
 	{"dac081s101", ID_AD5300}, /* compatible Texas Instruments chips */
 	{"dac101s101", ID_AD5310},
 	{"dac121s101", ID_AD5320},
 	{"dac7512", ID_AD5320},
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);

 static const struct of_device_id ad5446_of_ids[] = {
 	{ .compatible = "ti,dac7512" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ad5446_of_ids);

 static int ad5446_spi_probe(struct spi_device *spi)
 {
 	const struct spi_device_id *id = spi_get_device_id(spi);

 	return ad5446_probe(&spi->dev, id->name,
 		&ad5446_spi_chip_info[id->driver_data]);
 }

 static int ad5446_spi_remove(struct spi_device *spi)
 {
 	return ad5446_remove(&spi->dev);
 }

 static struct spi_driver ad5446_spi_driver = {
 	.driver = {
 		.name	= "ad5446",
 		.of_match_table = ad5446_of_ids,
 	},
 	.probe		= ad5446_spi_probe,
 	.remove		= ad5446_spi_remove,
 	.id_table	= ad5446_spi_ids,
 };

 static int __init ad5446_spi_register_driver(void)
 {
 	return spi_register_driver(&ad5446_spi_driver);
 }

 static void ad5446_spi_unregister_driver(void)
 {
 	spi_unregister_driver(&ad5446_spi_driver);
 }

 #else

 static inline int ad5446_spi_register_driver(void) { return 0; }
 static inline void ad5446_spi_unregister_driver(void) { }

 #endif

 #if IS_ENABLED(CONFIG_I2C)

 static int ad5622_write(struct ad5446_state *st, unsigned val)
 {
 	struct i2c_client *client = to_i2c_client(st->dev);
 	__be16 data = cpu_to_be16(val);

 	return i2c_master_send(client, (char *)&data, sizeof(data));
 }

 /*
  * ad5446_supported_i2c_device_ids:
  * The AD5620/40/60 parts are available in different fixed internal reference
  * voltage options. The actual part numbers may look differently
  * (and a bit cryptic), however this style is used to make clear which
  * parts are supported here.
  */
 enum ad5446_supported_i2c_device_ids {
 	ID_AD5602,
 	ID_AD5612,
 	ID_AD5622,
 };

 static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
 	[ID_AD5602] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
 		.write = ad5622_write,
 	},
 	[ID_AD5612] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
 		.write = ad5622_write,
 	},
 	[ID_AD5622] = {
 		.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
 		.write = ad5622_write,
 	},
 };

 static int ad5446_i2c_probe(struct i2c_client *i2c,
 			    const struct i2c_device_id *id)
 {
 	return ad5446_probe(&i2c->dev, id->name,
 		&ad5446_i2c_chip_info[id->driver_data]);
 }

 static int ad5446_i2c_remove(struct i2c_client *i2c)
 {
 	return ad5446_remove(&i2c->dev);
 }

 static const struct i2c_device_id ad5446_i2c_ids[] = {
 	{"ad5301", ID_AD5602},
 	{"ad5311", ID_AD5612},
 	{"ad5321", ID_AD5622},
 	{"ad5602", ID_AD5602},
 	{"ad5612", ID_AD5612},
 	{"ad5622", ID_AD5622},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);

 static struct i2c_driver ad5446_i2c_driver = {
 	.driver = {
 		   .name = "ad5446",
 	},
 	.probe = ad5446_i2c_probe,
 	.remove = ad5446_i2c_remove,
 	.id_table = ad5446_i2c_ids,
 };

 static int __init ad5446_i2c_register_driver(void)
 {
 	return i2c_add_driver(&ad5446_i2c_driver);
 }

 static void __exit ad5446_i2c_unregister_driver(void)
 {
 	i2c_del_driver(&ad5446_i2c_driver);
 }

 #else

 static inline int ad5446_i2c_register_driver(void) { return 0; }
 static inline void ad5446_i2c_unregister_driver(void) { }

 #endif

 static int __init ad5446_init(void)
 {
 	int ret;

 	ret = ad5446_spi_register_driver();
 	if (ret)
 		return ret;

 	ret = ad5446_i2c_register_driver();
 	if (ret) {
 		ad5446_spi_unregister_driver();
 		return ret;
 	}

 	return 0;
 }
 module_init(ad5446_init);

 static void __exit ad5446_exit(void)
 {
 	ad5446_i2c_unregister_driver();
 	ad5446_spi_unregister_driver();
 }
 module_exit(ad5446_exit);

 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* AD5446 SPI DAC driver
	*
	* Copyright 2010 Analog Devices Inc.
	*/

	#include <linux/interrupt.h>
	#include <linux/workqueue.h>
	#include <linux/device.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/sysfs.h>
	#include <linux/list.h>
	#include <linux/spi/spi.h>
	#include <linux/i2c.h>
	#include <linux/regulator/consumer.h>
	#include <linux/err.h>
	#include <linux/module.h>
	#include <linux/mod_devicetable.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>

	#include <asm/unaligned.h>

	#define MODE_PWRDWN_1k 0x1
	#define MODE_PWRDWN_100k 0x2
	#define MODE_PWRDWN_TRISTATE 0x3

	/**
	* struct ad5446_state - driver instance specific data
	* @dev: this device
	* @chip_info: chip model specific constants, available modes etc
	* @reg: supply regulator
	* @vref_mv: actual reference voltage used
	* @cached_val: store/retrieve values during power down
	* @pwr_down_mode: power down mode (1k, 100k or tristate)
	* @pwr_down: true if the device is in power down
	* @lock: lock to protect the data buffer during write ops
	*/

	struct ad5446_state {
	struct device *dev;
	const struct ad5446_chip_info *chip_info;
	struct regulator *reg;
	unsigned short vref_mv;
	unsigned cached_val;
	unsigned pwr_down_mode;
	unsigned pwr_down;
	struct mutex lock;
	};

	/**
	* struct ad5446_chip_info - chip specific information
	* @channel: channel spec for the DAC
	* @int_vref_mv: AD5620/40/60: the internal reference voltage
	* @write: chip specific helper function to write to the register
	*/

	struct ad5446_chip_info {
	struct iio_chan_spec channel;
	u16 int_vref_mv;
	int (write)(struct ad5446_state st, unsigned val);
	};

	static const char * const ad5446_powerdown_modes[] = {
	"1kohm_to_gnd", "100kohm_to_gnd", "three_state"
	};

	static int ad5446_set_powerdown_mode(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, unsigned int mode)
	{
	struct ad5446_state *st = iio_priv(indio_dev);

	st->pwr_down_mode = mode + 1;

	return 0;
	}

	static int ad5446_get_powerdown_mode(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan)
	{
	struct ad5446_state *st = iio_priv(indio_dev);

	return st->pwr_down_mode - 1;
	}

	static const struct iio_enum ad5446_powerdown_mode_enum = {
	.items = ad5446_powerdown_modes,
	.num_items = ARRAY_SIZE(ad5446_powerdown_modes),
	.get = ad5446_get_powerdown_mode,
	.set = ad5446_set_powerdown_mode,
	};

	static ssize_t ad5446_read_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private,
	const struct iio_chan_spec *chan,
	char *buf)
	{
	struct ad5446_state *st = iio_priv(indio_dev);

	return sprintf(buf, "%d\n", st->pwr_down);
	}

	static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
	uintptr_t private,
	const struct iio_chan_spec *chan,
	const char *buf, size_t len)
	{
	struct ad5446_state *st = iio_priv(indio_dev);
	unsigned int shift;
	unsigned int val;
	bool powerdown;
	int ret;

	ret = strtobool(buf, &powerdown);
	if (ret)
	return ret;

	mutex_lock(&st->lock);
	st->pwr_down = powerdown;

	if (st->pwr_down) {
	shift = chan->scan_type.realbits + chan->scan_type.shift;
	val = st->pwr_down_mode << shift;
	} else {
	val = st->cached_val;
	}

	ret = st->chip_info->write(st, val);
	mutex_unlock(&st->lock);

	return ret ? ret : len;
	}

	static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
	{
	.name = "powerdown",
	.read = ad5446_read_dac_powerdown,
	.write = ad5446_write_dac_powerdown,
	.shared = IIO_SEPARATE,
	},
	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5446_powerdown_mode_enum),
	{ },
	};

	#define _AD5446_CHANNEL(bits, storage, _shift, ext) { \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.output = 1, \
	.channel = 0, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = (bits), \
	.storagebits = (storage), \
	.shift = (_shift), \
	}, \
	.ext_info = (ext), \
	}

	#define AD5446_CHANNEL(bits, storage, shift) \
	_AD5446_CHANNEL(bits, storage, shift, NULL)

	#define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
	_AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)

	static int ad5446_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int *val,
	int *val2,
	long m)
	{
	struct ad5446_state *st = iio_priv(indio_dev);

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

	static int ad5446_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val,
	int val2,
	long mask)
	{
	struct ad5446_state *st = iio_priv(indio_dev);
	int ret = 0;

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

	val <<= chan->scan_type.shift;
	mutex_lock(&st->lock);
	st->cached_val = val;
	if (!st->pwr_down)
	ret = st->chip_info->write(st, val);
	mutex_unlock(&st->lock);
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static const struct iio_info ad5446_info = {
	.read_raw = ad5446_read_raw,
	.write_raw = ad5446_write_raw,
	};

	static int ad5446_probe(struct device dev, const char name,
	const struct ad5446_chip_info *chip_info)
	{
	struct ad5446_state *st;
	struct iio_dev *indio_dev;
	struct regulator *reg;
	int ret, voltage_uv = 0;

	reg = devm_regulator_get(dev, "vcc");
	if (!IS_ERR(reg)) {
	ret = regulator_enable(reg);
	if (ret)
	return ret;

	ret = regulator_get_voltage(reg);
	if (ret < 0)
	goto error_disable_reg;

	voltage_uv = ret;
	}

	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
	if (indio_dev == NULL) {
	ret = -ENOMEM;
	goto error_disable_reg;
	}
	st = iio_priv(indio_dev);
	st->chip_info = chip_info;

	dev_set_drvdata(dev, indio_dev);
	st->reg = reg;
	st->dev = dev;

	indio_dev->name = name;
	indio_dev->info = &ad5446_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = &st->chip_info->channel;
	indio_dev->num_channels = 1;

	mutex_init(&st->lock);

	st->pwr_down_mode = MODE_PWRDWN_1k;

	if (st->chip_info->int_vref_mv)
	st->vref_mv = st->chip_info->int_vref_mv;
	else if (voltage_uv)
	st->vref_mv = voltage_uv / 1000;
	else
	dev_warn(dev, "reference voltage unspecified\n");

	ret = iio_device_register(indio_dev);
	if (ret)
	goto error_disable_reg;

	return 0;

	error_disable_reg:
	if (!IS_ERR(reg))
	regulator_disable(reg);
	return ret;
	}

	static int ad5446_remove(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct ad5446_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	if (!IS_ERR(st->reg))
	regulator_disable(st->reg);

	return 0;
	}

	#if IS_ENABLED(CONFIG_SPI_MASTER)

	static int ad5446_write(struct ad5446_state *st, unsigned val)
	{
	struct spi_device *spi = to_spi_device(st->dev);
	__be16 data = cpu_to_be16(val);

	return spi_write(spi, &data, sizeof(data));
	}

	static int ad5660_write(struct ad5446_state *st, unsigned val)
	{
	struct spi_device *spi = to_spi_device(st->dev);
	uint8_t data[3];

	put_unaligned_be24(val, &data[0]);

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

	/*
	* ad5446_supported_spi_device_ids:
	* The AD5620/40/60 parts are available in different fixed internal reference
	* voltage options. The actual part numbers may look differently
	* (and a bit cryptic), however this style is used to make clear which
	* parts are supported here.
	*/
	enum ad5446_supported_spi_device_ids {
	ID_AD5300,
	ID_AD5310,
	ID_AD5320,
	ID_AD5444,
	ID_AD5446,
	ID_AD5450,
	ID_AD5451,
	ID_AD5541A,
	ID_AD5512A,
	ID_AD5553,
	ID_AD5600,
	ID_AD5601,
	ID_AD5611,
	ID_AD5621,
	ID_AD5641,
	ID_AD5620_2500,
	ID_AD5620_1250,
	ID_AD5640_2500,
	ID_AD5640_1250,
	ID_AD5660_2500,
	ID_AD5660_1250,
	ID_AD5662,
	};

	static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
	[ID_AD5300] = {
	.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
	.write = ad5446_write,
	},
	[ID_AD5310] = {
	.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
	.write = ad5446_write,
	},
	[ID_AD5320] = {
	.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
	.write = ad5446_write,
	},
	[ID_AD5444] = {
	.channel = AD5446_CHANNEL(12, 16, 2),
	.write = ad5446_write,
	},
	[ID_AD5446] = {
	.channel = AD5446_CHANNEL(14, 16, 0),
	.write = ad5446_write,
	},
	[ID_AD5450] = {
	.channel = AD5446_CHANNEL(8, 16, 6),
	.write = ad5446_write,
	},
	[ID_AD5451] = {
	.channel = AD5446_CHANNEL(10, 16, 4),
	.write = ad5446_write,
	},
	[ID_AD5541A] = {
	.channel = AD5446_CHANNEL(16, 16, 0),
	.write = ad5446_write,
	},
	[ID_AD5512A] = {
	.channel = AD5446_CHANNEL(12, 16, 4),
	.write = ad5446_write,
	},
	[ID_AD5553] = {
	.channel = AD5446_CHANNEL(14, 16, 0),
	.write = ad5446_write,
	},
	[ID_AD5600] = {
	.channel = AD5446_CHANNEL(16, 16, 0),
	.write = ad5446_write,
	},
	[ID_AD5601] = {
	.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
	.write = ad5446_write,
	},
	[ID_AD5611] = {
	.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
	.write = ad5446_write,
	},
	[ID_AD5621] = {
	.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
	.write = ad5446_write,
	},
	[ID_AD5641] = {
	.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
	.write = ad5446_write,
	},
	[ID_AD5620_2500] = {
	.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
	.int_vref_mv = 2500,
	.write = ad5446_write,
	},
	[ID_AD5620_1250] = {
	.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
	.int_vref_mv = 1250,
	.write = ad5446_write,
	},
	[ID_AD5640_2500] = {
	.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
	.int_vref_mv = 2500,
	.write = ad5446_write,
	},
	[ID_AD5640_1250] = {
	.channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
	.int_vref_mv = 1250,
	.write = ad5446_write,
	},
	[ID_AD5660_2500] = {
	.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
	.int_vref_mv = 2500,
	.write = ad5660_write,
	},
	[ID_AD5660_1250] = {
	.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
	.int_vref_mv = 1250,
	.write = ad5660_write,
	},
	[ID_AD5662] = {
	.channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
	.write = ad5660_write,
	},
	};

	static const struct spi_device_id ad5446_spi_ids[] = {
	{"ad5300", ID_AD5300},
	{"ad5310", ID_AD5310},
	{"ad5320", ID_AD5320},
	{"ad5444", ID_AD5444},
	{"ad5446", ID_AD5446},
	{"ad5450", ID_AD5450},
	{"ad5451", ID_AD5451},
	{"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
	{"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
	{"ad5512a", ID_AD5512A},
	{"ad5541a", ID_AD5541A},
	{"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
	{"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
	{"ad5553", ID_AD5553},
	{"ad5600", ID_AD5600},
	{"ad5601", ID_AD5601},
	{"ad5611", ID_AD5611},
	{"ad5621", ID_AD5621},
	{"ad5641", ID_AD5641},
	{"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
	{"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
	{"ad5640-2500", ID_AD5640_2500},
	{"ad5640-1250", ID_AD5640_1250},
	{"ad5660-2500", ID_AD5660_2500},
	{"ad5660-1250", ID_AD5660_1250},
	{"ad5662", ID_AD5662},
	{"dac081s101", ID_AD5300}, /* compatible Texas Instruments chips */
	{"dac101s101", ID_AD5310},
	{"dac121s101", ID_AD5320},
	{"dac7512", ID_AD5320},
	{}
	};
	MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);

	static const struct of_device_id ad5446_of_ids[] = {
	{ .compatible = "ti,dac7512" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, ad5446_of_ids);

	static int ad5446_spi_probe(struct spi_device *spi)
	{
	const struct spi_device_id *id = spi_get_device_id(spi);

	return ad5446_probe(&spi->dev, id->name,
	&ad5446_spi_chip_info[id->driver_data]);
	}

	static int ad5446_spi_remove(struct spi_device *spi)
	{
	return ad5446_remove(&spi->dev);
	}

	static struct spi_driver ad5446_spi_driver = {
	.driver = {
	.name = "ad5446",
	.of_match_table = ad5446_of_ids,
	},
	.probe = ad5446_spi_probe,
	.remove = ad5446_spi_remove,
	.id_table = ad5446_spi_ids,
	};

	static int __init ad5446_spi_register_driver(void)
	{
	return spi_register_driver(&ad5446_spi_driver);
	}

	static void ad5446_spi_unregister_driver(void)
	{
	spi_unregister_driver(&ad5446_spi_driver);
	}

	#else

	static inline int ad5446_spi_register_driver(void) { return 0; }
	static inline void ad5446_spi_unregister_driver(void) { }

	#endif

	#if IS_ENABLED(CONFIG_I2C)

	static int ad5622_write(struct ad5446_state *st, unsigned val)
	{
	struct i2c_client *client = to_i2c_client(st->dev);
	__be16 data = cpu_to_be16(val);

	return i2c_master_send(client, (char *)&data, sizeof(data));
	}

	/*
	* ad5446_supported_i2c_device_ids:
	* The AD5620/40/60 parts are available in different fixed internal reference
	* voltage options. The actual part numbers may look differently
	* (and a bit cryptic), however this style is used to make clear which
	* parts are supported here.
	*/
	enum ad5446_supported_i2c_device_ids {
	ID_AD5602,
	ID_AD5612,
	ID_AD5622,
	};

	static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
	[ID_AD5602] = {
	.channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
	.write = ad5622_write,
	},
	[ID_AD5612] = {
	.channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
	.write = ad5622_write,
	},
	[ID_AD5622] = {
	.channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
	.write = ad5622_write,
	},
	};

	static int ad5446_i2c_probe(struct i2c_client *i2c,
	const struct i2c_device_id *id)
	{
	return ad5446_probe(&i2c->dev, id->name,
	&ad5446_i2c_chip_info[id->driver_data]);
	}

	static int ad5446_i2c_remove(struct i2c_client *i2c)
	{
	return ad5446_remove(&i2c->dev);
	}

	static const struct i2c_device_id ad5446_i2c_ids[] = {
	{"ad5301", ID_AD5602},
	{"ad5311", ID_AD5612},
	{"ad5321", ID_AD5622},
	{"ad5602", ID_AD5602},
	{"ad5612", ID_AD5612},
	{"ad5622", ID_AD5622},
	{}
	};
	MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);

	static struct i2c_driver ad5446_i2c_driver = {
	.driver = {
	.name = "ad5446",
	},
	.probe = ad5446_i2c_probe,
	.remove = ad5446_i2c_remove,
	.id_table = ad5446_i2c_ids,
	};

	static int __init ad5446_i2c_register_driver(void)
	{
	return i2c_add_driver(&ad5446_i2c_driver);
	}

	static void __exit ad5446_i2c_unregister_driver(void)
	{
	i2c_del_driver(&ad5446_i2c_driver);
	}

	#else

	static inline int ad5446_i2c_register_driver(void) { return 0; }
	static inline void ad5446_i2c_unregister_driver(void) { }

	#endif

	static int __init ad5446_init(void)
	{
	int ret;

	ret = ad5446_spi_register_driver();
	if (ret)
	return ret;

	ret = ad5446_i2c_register_driver();
	if (ret) {
	ad5446_spi_unregister_driver();
	return ret;
	}

	return 0;
	}
	module_init(ad5446_init);

	static void __exit ad5446_exit(void)
	{
	ad5446_i2c_unregister_driver();
	ad5446_spi_unregister_driver();
	}
	module_exit(ad5446_exit);

	MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
	MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
	MODULE_LICENSE("GPL v2");