// SPDX-License-Identifier: GPL-2.0-only
/*
 * Analog devices AD5380, AD5381, AD5382, AD5383, AD5390, AD5391, AD5392
 * multi-channel Digital to Analog Converters driver
 *
 * Copyright 2011 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

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

#define AD5380_REG_DATA(x)      (((x) << 2) | 3)
#define AD5380_REG_OFFSET(x)    (((x) << 2) | 2)
#define AD5380_REG_GAIN(x)      (((x) << 2) | 1)
#define AD5380_REG_SF_PWR_DOWN  (8 << 2)
#define AD5380_REG_SF_PWR_UP    (9 << 2)
#define AD5380_REG_SF_CTRL      (12 << 2)

#define AD5380_CTRL_PWR_DOWN_MODE_OFFSET        13
#define AD5380_CTRL_INT_VREF_2V5                BIT(12)
#define AD5380_CTRL_INT_VREF_EN                 BIT(10)

/**
 * struct ad5380_chip_info - chip specific information
 * @channel_template:   channel specification template
 * @num_channels:       number of channels
 * @int_vref:           internal vref in uV
*/

struct ad5380_chip_info {
        struct iio_chan_spec    channel_template;
        unsigned int            num_channels;
        unsigned int            int_vref;
};

/**
 * struct ad5380_state - driver instance specific data
 * @regmap:             regmap instance used by the device
 * @chip_info:          chip model specific constants, available modes etc
 * @vref_reg:           vref supply regulator
 * @vref:               actual reference voltage used in uA
 * @pwr_down:           whether the chip is currently in power down mode
 * @lock:               lock to protect the data buffer during regmap ops
 */

struct ad5380_state {
        struct regmap                   *regmap;
        const struct ad5380_chip_info   *chip_info;
        struct regulator                *vref_reg;
        int                             vref;
        bool                            pwr_down;
        struct mutex                    lock;
};

enum ad5380_type {
        ID_AD5380_3,
        ID_AD5380_5,
        ID_AD5381_3,
        ID_AD5381_5,
        ID_AD5382_3,
        ID_AD5382_5,
        ID_AD5383_3,
        ID_AD5383_5,
        ID_AD5390_3,
        ID_AD5390_5,
        ID_AD5391_3,
        ID_AD5391_5,
        ID_AD5392_3,
        ID_AD5392_5,
};

static ssize_t ad5380_read_dac_powerdown(struct iio_dev *indio_dev,
        uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
        struct ad5380_state *st = iio_priv(indio_dev);

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

static ssize_t ad5380_write_dac_powerdown(struct iio_dev *indio_dev,
         uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
         size_t len)
{
        struct ad5380_state *st = iio_priv(indio_dev);
        bool pwr_down;
        int ret;

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

        mutex_lock(&st->lock);

        if (pwr_down)
                ret = regmap_write(st->regmap, AD5380_REG_SF_PWR_DOWN, 0);
        else
                ret = regmap_write(st->regmap, AD5380_REG_SF_PWR_UP, 0);

        st->pwr_down = pwr_down;

        mutex_unlock(&st->lock);

        return ret ? ret : len;
}

static const char * const ad5380_powerdown_modes[] = {
        "100kohm_to_gnd",
        "three_state",
};

static int ad5380_get_powerdown_mode(struct iio_dev *indio_dev,
        const struct iio_chan_spec *chan)
{
        struct ad5380_state *st = iio_priv(indio_dev);
        unsigned int mode;
        int ret;

        ret = regmap_read(st->regmap, AD5380_REG_SF_CTRL, &mode);
        if (ret)
                return ret;

        mode = (mode >> AD5380_CTRL_PWR_DOWN_MODE_OFFSET) & 1;

        return mode;
}

static int ad5380_set_powerdown_mode(struct iio_dev *indio_dev,
        const struct iio_chan_spec *chan, unsigned int mode)
{
        struct ad5380_state *st = iio_priv(indio_dev);
        int ret;

        ret = regmap_update_bits(st->regmap, AD5380_REG_SF_CTRL,
                1 << AD5380_CTRL_PWR_DOWN_MODE_OFFSET,
                mode << AD5380_CTRL_PWR_DOWN_MODE_OFFSET);

        return ret;
}

static const struct iio_enum ad5380_powerdown_mode_enum = {
        .items = ad5380_powerdown_modes,
        .num_items = ARRAY_SIZE(ad5380_powerdown_modes),
        .get = ad5380_get_powerdown_mode,
        .set = ad5380_set_powerdown_mode,
};

static unsigned int ad5380_info_to_reg(struct iio_chan_spec const *chan,
        long info)
{
        switch (info) {
        case IIO_CHAN_INFO_RAW:
                return AD5380_REG_DATA(chan->address);
        case IIO_CHAN_INFO_CALIBBIAS:
                return AD5380_REG_OFFSET(chan->address);
        case IIO_CHAN_INFO_CALIBSCALE:
                return AD5380_REG_GAIN(chan->address);
        default:
                break;
        }

        return 0;
}

static int ad5380_write_raw(struct iio_dev *indio_dev,
        struct iio_chan_spec const *chan, int val, int val2, long info)
{
        const unsigned int max_val = (1 << chan->scan_type.realbits);
        struct ad5380_state *st = iio_priv(indio_dev);

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

                return regmap_write(st->regmap,
                        ad5380_info_to_reg(chan, info),
                        val << chan->scan_type.shift);
        case IIO_CHAN_INFO_CALIBBIAS:
                val += (1 << chan->scan_type.realbits) / 2;
                if (val >= max_val || val < 0)
                        return -EINVAL;

                return regmap_write(st->regmap,
                        AD5380_REG_OFFSET(chan->address),
                        val << chan->scan_type.shift);
        default:
                break;
        }
        return -EINVAL;
}

static int ad5380_read_raw(struct iio_dev *indio_dev,
        struct iio_chan_spec const *chan, int *val, int *val2, long info)
{
        struct ad5380_state *st = iio_priv(indio_dev);
        int ret;

        switch (info) {
        case IIO_CHAN_INFO_RAW:
        case IIO_CHAN_INFO_CALIBSCALE:
                ret = regmap_read(st->regmap, ad5380_info_to_reg(chan, info),
                                        val);
                if (ret)
                        return ret;
                *val >>= chan->scan_type.shift;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_CALIBBIAS:
                ret = regmap_read(st->regmap, AD5380_REG_OFFSET(chan->address),
                                        val);
                if (ret)
                        return ret;
                *val >>= chan->scan_type.shift;
                *val -= (1 << chan->scan_type.realbits) / 2;
                return IIO_VAL_INT;
        case IIO_CHAN_INFO_SCALE:
                *val = 2 * st->vref;
                *val2 = chan->scan_type.realbits;
                return IIO_VAL_FRACTIONAL_LOG2;
        default:
                break;
        }

        return -EINVAL;
}

static const struct iio_info ad5380_info = {
        .read_raw = ad5380_read_raw,
        .write_raw = ad5380_write_raw,
};

static const struct iio_chan_spec_ext_info ad5380_ext_info[] = {
        {
                .name = "powerdown",
                .read = ad5380_read_dac_powerdown,
                .write = ad5380_write_dac_powerdown,
                .shared = IIO_SEPARATE,
        },
        IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
                 &ad5380_powerdown_mode_enum),
        IIO_ENUM_AVAILABLE("powerdown_mode", &ad5380_powerdown_mode_enum),
        { },
};

#define AD5380_CHANNEL(_bits) {                                 \
        .type = IIO_VOLTAGE,                                    \
        .indexed = 1,                                           \
        .output = 1,                                            \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
                BIT(IIO_CHAN_INFO_CALIBSCALE) |                 \
                BIT(IIO_CHAN_INFO_CALIBBIAS),                   \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
        .scan_type = {                                          \
                .sign = 'u',                                    \
                .realbits = (_bits),                            \
                .storagebits =  16,                             \
                .shift = 14 - (_bits),                          \
        },                                                      \
        .ext_info = ad5380_ext_info,                            \
}

static const struct ad5380_chip_info ad5380_chip_info_tbl[] = {
        [ID_AD5380_3] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 40,
                .int_vref = 1250,
        },
        [ID_AD5380_5] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 40,
                .int_vref = 2500,
        },
        [ID_AD5381_3] = {
                .channel_template = AD5380_CHANNEL(12),
                .num_channels = 16,
                .int_vref = 1250,
        },
        [ID_AD5381_5] = {
                .channel_template = AD5380_CHANNEL(12),
                .num_channels = 16,
                .int_vref = 2500,
        },
        [ID_AD5382_3] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 32,
                .int_vref = 1250,
        },
        [ID_AD5382_5] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 32,
                .int_vref = 2500,
        },
        [ID_AD5383_3] = {
                .channel_template = AD5380_CHANNEL(12),
                .num_channels = 32,
                .int_vref = 1250,
        },
        [ID_AD5383_5] = {
                .channel_template = AD5380_CHANNEL(12),
                .num_channels = 32,
                .int_vref = 2500,
        },
        [ID_AD5390_3] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 16,
                .int_vref = 1250,
        },
        [ID_AD5390_5] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 16,
                .int_vref = 2500,
        },
        [ID_AD5391_3] = {
                .channel_template = AD5380_CHANNEL(12),
                .num_channels = 16,
                .int_vref = 1250,
        },
        [ID_AD5391_5] = {
                .channel_template = AD5380_CHANNEL(12),
                .num_channels = 16,
                .int_vref = 2500,
        },
        [ID_AD5392_3] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 8,
                .int_vref = 1250,
        },
        [ID_AD5392_5] = {
                .channel_template = AD5380_CHANNEL(14),
                .num_channels = 8,
                .int_vref = 2500,
        },
};

static int ad5380_alloc_channels(struct iio_dev *indio_dev)
{
        struct ad5380_state *st = iio_priv(indio_dev);
        struct iio_chan_spec *channels;
        unsigned int i;

        channels = kcalloc(st->chip_info->num_channels,
                           sizeof(struct iio_chan_spec), GFP_KERNEL);

        if (!channels)
                return -ENOMEM;

        for (i = 0; i < st->chip_info->num_channels; ++i) {
                channels[i] = st->chip_info->channel_template;
                channels[i].channel = i;
                channels[i].address = i;
        }

        indio_dev->channels = channels;

        return 0;
}

static int ad5380_probe(struct device *dev, struct regmap *regmap,
                        enum ad5380_type type, const char *name)
{
        struct iio_dev *indio_dev;
        struct ad5380_state *st;
        unsigned int ctrl = 0;
        int ret;

        indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
        if (indio_dev == NULL) {
                dev_err(dev, "Failed to allocate iio device\n");
                return -ENOMEM;
        }

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

        st->chip_info = &ad5380_chip_info_tbl[type];
        st->regmap = regmap;

        indio_dev->name = name;
        indio_dev->info = &ad5380_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->num_channels = st->chip_info->num_channels;

        mutex_init(&st->lock);

        ret = ad5380_alloc_channels(indio_dev);
        if (ret) {
                dev_err(dev, "Failed to allocate channel spec: %d\n", ret);
                return ret;
        }

        if (st->chip_info->int_vref == 2500)
                ctrl |= AD5380_CTRL_INT_VREF_2V5;

        st->vref_reg = devm_regulator_get(dev, "vref");
        if (!IS_ERR(st->vref_reg)) {
                ret = regulator_enable(st->vref_reg);
                if (ret) {
                        dev_err(dev, "Failed to enable vref regulators: %d\n",
                                ret);
                        goto error_free_reg;
                }

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

                st->vref = ret / 1000;
        } else {
                st->vref = st->chip_info->int_vref;
                ctrl |= AD5380_CTRL_INT_VREF_EN;
        }

        ret = regmap_write(st->regmap, AD5380_REG_SF_CTRL, ctrl);
        if (ret) {
                dev_err(dev, "Failed to write to device: %d\n", ret);
                goto error_disable_reg;
        }

        ret = iio_device_register(indio_dev);
        if (ret) {
                dev_err(dev, "Failed to register iio device: %d\n", ret);
                goto error_disable_reg;
        }

        return 0;

error_disable_reg:
        if (!IS_ERR(st->vref_reg))
                regulator_disable(st->vref_reg);
error_free_reg:
        kfree(indio_dev->channels);

        return ret;
}

static int ad5380_remove(struct device *dev)
{
        struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct ad5380_state *st = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);

        kfree(indio_dev->channels);

        if (!IS_ERR(st->vref_reg)) {
                regulator_disable(st->vref_reg);
        }

        return 0;
}

static bool ad5380_reg_false(struct device *dev, unsigned int reg)
{
        return false;
}

static const struct regmap_config ad5380_regmap_config = {
        .reg_bits = 10,
        .val_bits = 14,

        .max_register = AD5380_REG_DATA(40),
        .cache_type = REGCACHE_RBTREE,

        .volatile_reg = ad5380_reg_false,
        .readable_reg = ad5380_reg_false,
};

#if IS_ENABLED(CONFIG_SPI_MASTER)

static int ad5380_spi_probe(struct spi_device *spi)
{
        const struct spi_device_id *id = spi_get_device_id(spi);
        struct regmap *regmap;

        regmap = devm_regmap_init_spi(spi, &ad5380_regmap_config);

        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        return ad5380_probe(&spi->dev, regmap, id->driver_data, id->name);
}

static int ad5380_spi_remove(struct spi_device *spi)
{
        return ad5380_remove(&spi->dev);
}

static const struct spi_device_id ad5380_spi_ids[] = {
        { "ad5380-3", ID_AD5380_3 },
        { "ad5380-5", ID_AD5380_5 },
        { "ad5381-3", ID_AD5381_3 },
        { "ad5381-5", ID_AD5381_5 },
        { "ad5382-3", ID_AD5382_3 },
        { "ad5382-5", ID_AD5382_5 },
        { "ad5383-3", ID_AD5383_3 },
        { "ad5383-5", ID_AD5383_5 },
        { "ad5384-3", ID_AD5380_3 },
        { "ad5384-5", ID_AD5380_5 },
        { "ad5390-3", ID_AD5390_3 },
        { "ad5390-5", ID_AD5390_5 },
        { "ad5391-3", ID_AD5391_3 },
        { "ad5391-5", ID_AD5391_5 },
        { "ad5392-3", ID_AD5392_3 },
        { "ad5392-5", ID_AD5392_5 },
        { }
};
MODULE_DEVICE_TABLE(spi, ad5380_spi_ids);

static struct spi_driver ad5380_spi_driver = {
        .driver = {
                   .name = "ad5380",
        },
        .probe = ad5380_spi_probe,
        .remove = ad5380_spi_remove,
        .id_table = ad5380_spi_ids,
};

static inline int ad5380_spi_register_driver(void)
{
        return spi_register_driver(&ad5380_spi_driver);
}

static inline void ad5380_spi_unregister_driver(void)
{
        spi_unregister_driver(&ad5380_spi_driver);
}

#else

static inline int ad5380_spi_register_driver(void)
{
        return 0;
}

static inline void ad5380_spi_unregister_driver(void)
{
}

#endif

#if IS_ENABLED(CONFIG_I2C)

static int ad5380_i2c_probe(struct i2c_client *i2c,
                            const struct i2c_device_id *id)
{
        struct regmap *regmap;

        regmap = devm_regmap_init_i2c(i2c, &ad5380_regmap_config);

        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        return ad5380_probe(&i2c->dev, regmap, id->driver_data, id->name);
}

static int ad5380_i2c_remove(struct i2c_client *i2c)
{
        return ad5380_remove(&i2c->dev);
}

static const struct i2c_device_id ad5380_i2c_ids[] = {
        { "ad5380-3", ID_AD5380_3 },
        { "ad5380-5", ID_AD5380_5 },
        { "ad5381-3", ID_AD5381_3 },
        { "ad5381-5", ID_AD5381_5 },
        { "ad5382-3", ID_AD5382_3 },
        { "ad5382-5", ID_AD5382_5 },
        { "ad5383-3", ID_AD5383_3 },
        { "ad5383-5", ID_AD5383_5 },
        { "ad5384-3", ID_AD5380_3 },
        { "ad5384-5", ID_AD5380_5 },
        { "ad5390-3", ID_AD5390_3 },
        { "ad5390-5", ID_AD5390_5 },
        { "ad5391-3", ID_AD5391_3 },
        { "ad5391-5", ID_AD5391_5 },
        { "ad5392-3", ID_AD5392_3 },
        { "ad5392-5", ID_AD5392_5 },
        { }
};
MODULE_DEVICE_TABLE(i2c, ad5380_i2c_ids);

static struct i2c_driver ad5380_i2c_driver = {
        .driver = {
                   .name = "ad5380",
        },
        .probe = ad5380_i2c_probe,
        .remove = ad5380_i2c_remove,
        .id_table = ad5380_i2c_ids,
};

static inline int ad5380_i2c_register_driver(void)
{
        return i2c_add_driver(&ad5380_i2c_driver);
}

static inline void ad5380_i2c_unregister_driver(void)
{
        i2c_del_driver(&ad5380_i2c_driver);
}

#else

static inline int ad5380_i2c_register_driver(void)
{
        return 0;
}

static inline void ad5380_i2c_unregister_driver(void)
{
}

#endif

static int __init ad5380_spi_init(void)
{
        int ret;

        ret = ad5380_spi_register_driver();
        if (ret)
                return ret;

        ret = ad5380_i2c_register_driver();
        if (ret) {
                ad5380_spi_unregister_driver();
                return ret;
        }

        return 0;
}
module_init(ad5380_spi_init);

static void __exit ad5380_spi_exit(void)
{
        ad5380_i2c_unregister_driver();
        ad5380_spi_unregister_driver();

}
module_exit(ad5380_spi_exit);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Analog Devices AD5380/81/82/83/84/90/91/92 DAC");
MODULE_LICENSE("GPL v2");