linux/drivers/iio/dac/ad5686.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * AD5686R, AD5685R, AD5684R Digital to analog converters  driver
 *
 * Copyright 2011 Analog Devices Inc.
 */

#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regulator/consumer.h>

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

#include "ad5686.h"

static const char * const ad5686_powerdown_modes[] = {
	"1kohm_to_gnd",
	"100kohm_to_gnd",
	"three_state"
};

static int ad5686_get_powerdown_mode(struct iio_dev *indio_dev,
				     const struct iio_chan_spec *chan)
{
	struct ad5686_state *st = iio_priv(indio_dev);

	return ((st->pwr_down_mode >> (chan->channel * 2)) & 0x3) - 1;
}

static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev,
				     const struct iio_chan_spec *chan,
				     unsigned int mode)
{
	struct ad5686_state *st = iio_priv(indio_dev);

	st->pwr_down_mode &= ~(0x3 << (chan->channel * 2));
	st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2));

	return 0;
}

static const struct iio_enum ad5686_powerdown_mode_enum = {
	.items = ad5686_powerdown_modes,
	.num_items = ARRAY_SIZE(ad5686_powerdown_modes),
	.get = ad5686_get_powerdown_mode,
	.set = ad5686_set_powerdown_mode,
};

static ssize_t ad5686_read_dac_powerdown(struct iio_dev *indio_dev,
		uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
	struct ad5686_state *st = iio_priv(indio_dev);

	return sprintf(buf, "%d\n", !!(st->pwr_down_mask &
				       (0x3 << (chan->channel * 2))));
}

static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
					  uintptr_t private,
					  const struct iio_chan_spec *chan,
					  const char *buf,
					  size_t len)
{
	bool readin;
	int ret;
	struct ad5686_state *st = iio_priv(indio_dev);

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

	if (readin)
		st->pwr_down_mask |= (0x3 << (chan->channel * 2));
	else
		st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));

	ret = st->write(st, AD5686_CMD_POWERDOWN_DAC, 0,
			st->pwr_down_mask & st->pwr_down_mode);


	return ret ? ret : len;
}

static int ad5686_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	struct ad5686_state *st = iio_priv(indio_dev);
	int ret;

	switch (m) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&indio_dev->mlock);
		ret = st->read(st, chan->address);
		mutex_unlock(&indio_dev->mlock);
		if (ret < 0)
			return ret;
		*val = ret;
		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 ad5686_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val,
			    int val2,
			    long mask)
{
	struct ad5686_state *st = iio_priv(indio_dev);
	int ret;

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

		mutex_lock(&indio_dev->mlock);
		ret = st->write(st,
				AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
				chan->address,
				val << chan->scan_type.shift);
		mutex_unlock(&indio_dev->mlock);
		break;
	default:
		ret = -EINVAL;
	}

	return ret;
}

static const struct iio_info ad5686_info = {
	.read_raw = ad5686_read_raw,
	.write_raw = ad5686_write_raw,
};

static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
	{
		.name = "powerdown",
		.read = ad5686_read_dac_powerdown,
		.write = ad5686_write_dac_powerdown,
		.shared = IIO_SEPARATE,
	},
	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5686_powerdown_mode_enum),
	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
	{ },
};

#define AD5868_CHANNEL(chan, addr, bits, _shift) {		\
		.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 = addr,				\
		.scan_type = {					\
			.sign = 'u',				\
			.realbits = (bits),			\
			.storagebits = 16,			\
			.shift = (_shift),			\
		},						\
		.ext_info = ad5686_ext_info,			\
}

#define DECLARE_AD5686_CHANNELS(name, bits, _shift)		\
static struct iio_chan_spec name[] = {				\
		AD5868_CHANNEL(0, 1, bits, _shift),		\
		AD5868_CHANNEL(1, 2, bits, _shift),		\
		AD5868_CHANNEL(2, 4, bits, _shift),		\
		AD5868_CHANNEL(3, 8, bits, _shift),		\
}

#define DECLARE_AD5676_CHANNELS(name, bits, _shift)		\
static struct iio_chan_spec name[] = {				\
		AD5868_CHANNEL(0, 0, bits, _shift),		\
		AD5868_CHANNEL(1, 1, bits, _shift),		\
		AD5868_CHANNEL(2, 2, bits, _shift),		\
		AD5868_CHANNEL(3, 3, bits, _shift),		\
		AD5868_CHANNEL(4, 4, bits, _shift),		\
		AD5868_CHANNEL(5, 5, bits, _shift),		\
		AD5868_CHANNEL(6, 6, bits, _shift),		\
		AD5868_CHANNEL(7, 7, bits, _shift),		\
}

DECLARE_AD5676_CHANNELS(ad5672_channels, 12, 4);
DECLARE_AD5676_CHANNELS(ad5676_channels, 16, 0);
DECLARE_AD5686_CHANNELS(ad5684_channels, 12, 4);
DECLARE_AD5686_CHANNELS(ad5685r_channels, 14, 2);
DECLARE_AD5686_CHANNELS(ad5686_channels, 16, 0);

static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
	[ID_AD5672R] = {
		.channels = ad5672_channels,
		.int_vref_mv = 2500,
		.num_channels = 8,
	},
	[ID_AD5676] = {
		.channels = ad5676_channels,
		.num_channels = 8,
	},
	[ID_AD5676R] = {
		.channels = ad5676_channels,
		.int_vref_mv = 2500,
		.num_channels = 8,
	},
	[ID_AD5684] = {
		.channels = ad5684_channels,
		.num_channels = 4,
	},
	[ID_AD5684R] = {
		.channels = ad5684_channels,
		.int_vref_mv = 2500,
		.num_channels = 4,
	},
	[ID_AD5685R] = {
		.channels = ad5685r_channels,
		.int_vref_mv = 2500,
		.num_channels = 4,
	},
	[ID_AD5686] = {
		.channels = ad5686_channels,
		.num_channels = 4,
	},
	[ID_AD5686R] = {
		.channels = ad5686_channels,
		.int_vref_mv = 2500,
		.num_channels = 4,
	},
};

int ad5686_probe(struct device *dev,
		 enum ad5686_supported_device_ids chip_type,
		 const char *name, ad5686_write_func write,
		 ad5686_read_func read)
{
	struct ad5686_state *st;
	struct iio_dev *indio_dev;
	int ret, voltage_uv = 0;

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

	st = iio_priv(indio_dev);
	dev_set_drvdata(dev, indio_dev);

	st->dev = dev;
	st->write = write;
	st->read = read;

	st->reg = devm_regulator_get_optional(dev, "vcc");
	if (!IS_ERR(st->reg)) {
		ret = regulator_enable(st->reg);
		if (ret)
			return ret;

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

		voltage_uv = ret;
	}

	st->chip_info = &ad5686_chip_info_tbl[chip_type];

	if (voltage_uv)
		st->vref_mv = voltage_uv / 1000;
	else
		st->vref_mv = st->chip_info->int_vref_mv;

	/* Set all the power down mode for all channels to 1K pulldown */
	st->pwr_down_mode = 0x55;

	indio_dev->dev.parent = dev;
	indio_dev->name = name;
	indio_dev->info = &ad5686_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = st->chip_info->channels;
	indio_dev->num_channels = st->chip_info->num_channels;

	ret = st->write(st, AD5686_CMD_INTERNAL_REFER_SETUP,
			0, !!voltage_uv);
	if (ret)
		goto error_disable_reg;

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

	return 0;

error_disable_reg:
	if (!IS_ERR(st->reg))
		regulator_disable(st->reg);
	return ret;
}
EXPORT_SYMBOL_GPL(ad5686_probe);

int ad5686_remove(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct ad5686_state *st = iio_priv(indio_dev);

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

	return 0;
}
EXPORT_SYMBOL_GPL(ad5686_remove);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");
MODULE_LICENSE("GPL v2");