ad5446.c

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/*
 * AD5446 SPI DAC driver
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

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

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

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 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(&indio_dev->mlock);
    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(&indio_dev->mlock);

    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,
    },
    IIO_ENUM("powerdown_mode", false, &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 = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
    IIO_CHAN_INFO_SCALE_SHARED_BIT, \
    .scan_type = IIO_ST('u', (bits), (storage), (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);
    unsigned long scale_uv;

    switch (m) {
    case IIO_CHAN_INFO_RAW:
        *val = st->cached_val;
        return IIO_VAL_INT;
    case IIO_CHAN_INFO_SCALE:
        scale_uv = (st->vref_mv * 1000) >> chan->scan_type.realbits;
        *val =  scale_uv / 1000;
        *val2 = (scale_uv % 1000) * 1000;
        return IIO_VAL_INT_PLUS_MICRO;

    }
    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(&indio_dev->mlock);
        st->cached_val = val;
        if (!st->pwr_down)
            ret = st->chip_info->write(st, val);
        mutex_unlock(&indio_dev->mlock);
        break;
    default:
        ret = -EINVAL;
    }

    return ret;
}

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

static int __devinit 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 = regulator_get(dev, "vcc");
    if (!IS_ERR(reg)) {
        ret = regulator_enable(reg);
        if (ret)
            goto error_put_reg;

        voltage_uv = regulator_get_voltage(reg);
    }

    indio_dev = iio_device_alloc(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;

    /* Establish that the iio_dev is a child of the device */
    indio_dev->dev.parent = 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;

    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_free_device;

    return 0;

error_free_device:
    iio_device_free(indio_dev);
error_disable_reg:
    if (!IS_ERR(reg))
        regulator_disable(reg);
error_put_reg:
    if (!IS_ERR(reg))
        regulator_put(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);
        regulator_put(st->reg);
    }
    iio_device_free(indio_dev);

    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];

    data[0] = (val >> 16) & 0xFF;
    data[1] = (val >> 8) & 0xFF;
    data[2] = val & 0xFF;

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

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_AD5601,
    ID_AD5611,
    ID_AD5621,
    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_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_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},
    {"ad5601", ID_AD5601},
    {"ad5611", ID_AD5611},
    {"ad5621", ID_AD5621},
    {"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},
    {}
};
MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);

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

static struct spi_driver ad5446_spi_driver = {
    .driver = {
        .name   = "ad5446",
        .owner  = THIS_MODULE,
    },
    .probe      = ad5446_spi_probe,
    .remove     = __devexit_p(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));
}

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 __devinit 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 __devexit 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",
           .owner = THIS_MODULE,
    },
    .probe = ad5446_i2c_probe,
    .remove = __devexit_p(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 <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
MODULE_LICENSE("GPL v2");