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

#include <linux/array_size.h>
#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/iio/iio.h>
#include <linux/kstrtox.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regulator/consumer.h>
#include <linux/sysfs.h>

#include "ad5446.h"

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

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 sysfs_emit(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 = kstrtobool(buf, &powerdown);
        if (ret)
                return ret;

        guard(mutex)(&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);
        if (ret)
                return ret;

        return len;
}

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", IIO_SHARED_BY_TYPE, &ad5446_powerdown_mode_enum),
        { }
};
EXPORT_SYMBOL_NS_GPL(ad5446_ext_info_powerdown, "IIO_AD5446");

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 >> chan->scan_type.shift;
                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_dac_raw(struct iio_dev *indio_dev,
                                const struct iio_chan_spec *chan,
                                int val)
{
        struct ad5446_state *st = iio_priv(indio_dev);

        if (val >= (1 << chan->scan_type.realbits) || val < 0)
                return -EINVAL;

        val <<= chan->scan_type.shift;
        guard(mutex)(&st->lock);

        st->cached_val = val;
        if (st->pwr_down)
                return 0;

        return st->chip_info->write(st, val);
}

static int ad5446_write_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan, int val,
                            int val2, long mask)
{
        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                return ad5446_write_dac_raw(indio_dev, chan, val);
        default:
                return -EINVAL;
        }
}

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

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;
        int ret;

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

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

        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;

        ret = devm_mutex_init(dev, &st->lock);
        if (ret)
                return ret;

        st->pwr_down_mode = MODE_PWRDWN_1k;

        ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
        if (ret < 0 && ret != -ENODEV)
                return ret;
        if (ret == -ENODEV) {
                if (!chip_info->int_vref_mv)
                        return dev_err_probe(dev, ret,
                                             "reference voltage unspecified\n");

                st->vref_mv = chip_info->int_vref_mv;
        } else {
                st->vref_mv = ret / 1000;
        }

        return devm_iio_device_register(dev, indio_dev);
}
EXPORT_SYMBOL_NS_GPL(ad5446_probe, "IIO_AD5446");

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices CORE AD5446 DAC and similar devices");
MODULE_LICENSE("GPL v2");