ad5380.c

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/*
 * Analog devices AD5380, AD5381, AD5382, AD5383, AD5390, AD5391, AD5392
 * multi-channel Digital to Analog Converters driver
 *
 * Copyright 2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2.
 */

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

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

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 sprintf(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(&indio_dev->mlock);

    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(&indio_dev->mlock);

    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 0:
        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);
    unsigned long scale_uv;
    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:
        scale_uv = ((2 * st->vref) >> chan->scan_type.realbits) * 100;
        *val =  scale_uv / 100000;
        *val2 = (scale_uv % 100000) * 10;
        return IIO_VAL_INT_PLUS_MICRO;
    default:
        break;
    }

    return -EINVAL;
}

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

static struct iio_chan_spec_ext_info ad5380_ext_info[] = {
    {
        .name = "powerdown",
        .read = ad5380_read_dac_powerdown,
        .write = ad5380_write_dac_powerdown,
    },
    IIO_ENUM("powerdown_mode", true, &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 = IIO_CHAN_INFO_RAW_SEPARATE_BIT |       \
        IIO_CHAN_INFO_SCALE_SHARED_BIT |        \
        IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT |     \
        IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT,       \
    .scan_type = IIO_ST('u', (_bits), 16, 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 = 1250000,
    },
    [ID_AD5380_5] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 40,
        .int_vref = 2500000,
    },
    [ID_AD5381_3] = {
        .channel_template = AD5380_CHANNEL(12),
        .num_channels = 16,
        .int_vref = 1250000,
    },
    [ID_AD5381_5] = {
        .channel_template = AD5380_CHANNEL(12),
        .num_channels = 16,
        .int_vref = 2500000,
    },
    [ID_AD5382_3] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 32,
        .int_vref = 1250000,
    },
    [ID_AD5382_5] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 32,
        .int_vref = 2500000,
    },
    [ID_AD5383_3] = {
        .channel_template = AD5380_CHANNEL(12),
        .num_channels = 32,
        .int_vref = 1250000,
    },
    [ID_AD5383_5] = {
        .channel_template = AD5380_CHANNEL(12),
        .num_channels = 32,
        .int_vref = 2500000,
    },
    [ID_AD5390_3] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 16,
        .int_vref = 1250000,
    },
    [ID_AD5390_5] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 16,
        .int_vref = 2500000,
    },
    [ID_AD5391_3] = {
        .channel_template = AD5380_CHANNEL(12),
        .num_channels = 16,
        .int_vref = 1250000,
    },
    [ID_AD5391_5] = {
        .channel_template = AD5380_CHANNEL(12),
        .num_channels = 16,
        .int_vref = 2500000,
    },
    [ID_AD5392_3] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 8,
        .int_vref = 1250000,
    },
    [ID_AD5392_5] = {
        .channel_template = AD5380_CHANNEL(14),
        .num_channels = 8,
        .int_vref = 2500000,
    },
};

static int __devinit 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 __devinit 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 = iio_device_alloc(sizeof(*st));
    if (indio_dev == NULL) {
        dev_err(dev, "Failed to allocate iio device\n");
        ret = -ENOMEM;
        goto error_out;
    }

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

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

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

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

    if (st->chip_info->int_vref == 2500000)
        ctrl |= AD5380_CTRL_INT_VREF_2V5;

    st->vref_reg = 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;
        }

        st->vref = regulator_get_voltage(st->vref_reg);
    } 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:
    if (!IS_ERR(st->vref_reg))
        regulator_put(st->vref_reg);

    kfree(indio_dev->channels);
error_free:
    iio_device_free(indio_dev);
error_out:

    return ret;
}

static int __devexit 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);
        regulator_put(st->vref_reg);
    }

    iio_device_free(indio_dev);

    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 __devinit 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 __devexit 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",
           .owner = THIS_MODULE,
    },
    .probe = ad5380_spi_probe,
    .remove = __devexit_p(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 __devinit 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 __devexit 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",
           .owner = THIS_MODULE,
    },
    .probe = ad5380_i2c_probe,
    .remove = __devexit_p(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 <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD5380/81/82/83/84/90/91/92 DAC");
MODULE_LICENSE("GPL v2");