root/drivers/iio/dac/ti-dac5571.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver
 *
 * Copyright (C) 2018 Prevas A/S
 *
 * https://www.ti.com/lit/ds/symlink/dac5571.pdf
 * https://www.ti.com/lit/ds/symlink/dac6571.pdf
 * https://www.ti.com/lit/ds/symlink/dac7571.pdf
 * https://www.ti.com/lit/ds/symlink/dac5574.pdf
 * https://www.ti.com/lit/ds/symlink/dac6574.pdf
 * https://www.ti.com/lit/ds/symlink/dac7574.pdf
 * https://www.ti.com/lit/ds/symlink/dac5573.pdf
 * https://www.ti.com/lit/ds/symlink/dac6573.pdf
 * https://www.ti.com/lit/ds/symlink/dac7573.pdf
 * https://www.ti.com/lit/ds/symlink/dac081c081.pdf
 * https://www.ti.com/lit/ds/symlink/dac121c081.pdf
 */

#include <linux/iio/iio.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>

enum chip_id {
        single_8bit, single_10bit, single_12bit,
        quad_8bit, quad_10bit, quad_12bit
};

struct dac5571_spec {
        u8 num_channels;
        u8 resolution;
};

static const struct dac5571_spec dac5571_spec[] = {
        [single_8bit]  = {.num_channels = 1, .resolution =  8},
        [single_10bit] = {.num_channels = 1, .resolution = 10},
        [single_12bit] = {.num_channels = 1, .resolution = 12},
        [quad_8bit]    = {.num_channels = 4, .resolution =  8},
        [quad_10bit]   = {.num_channels = 4, .resolution = 10},
        [quad_12bit]   = {.num_channels = 4, .resolution = 12},
};

struct dac5571_data {
        struct i2c_client *client;
        int id;
        struct mutex lock;
        struct regulator *vref;
        u16 val[4];
        bool powerdown[4];
        u8 powerdown_mode[4];
        struct dac5571_spec const *spec;
        int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
        int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
        u8 buf[3] __aligned(IIO_DMA_MINALIGN);
};

#define DAC5571_POWERDOWN(mode)         ((mode) + 1)
#define DAC5571_POWERDOWN_FLAG          BIT(0)
#define DAC5571_CHANNEL_SELECT          1
#define DAC5571_LOADMODE_DIRECT         BIT(4)
#define DAC5571_SINGLE_PWRDWN_BITS      4
#define DAC5571_QUAD_PWRDWN_BITS        6

static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
{
        unsigned int shift;

        shift = 12 - data->spec->resolution;
        data->buf[1] = val << shift;
        data->buf[0] = val >> (8 - shift);

        if (i2c_master_send(data->client, data->buf, 2) != 2)
                return -EIO;

        return 0;
}

static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
{
        unsigned int shift;

        shift = 16 - data->spec->resolution;
        data->buf[2] = val << shift;
        data->buf[1] = (val >> (8 - shift));
        data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
                       DAC5571_LOADMODE_DIRECT;

        if (i2c_master_send(data->client, data->buf, 3) != 3)
                return -EIO;

        return 0;
}

static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
{
        data->buf[1] = 0;
        data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;

        if (i2c_master_send(data->client, data->buf, 2) != 2)
                return -EIO;

        return 0;
}

static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
{
        data->buf[2] = 0;
        data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
        data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
                       DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;

        if (i2c_master_send(data->client, data->buf, 3) != 3)
                return -EIO;

        return 0;
}

static const char *const dac5571_powerdown_modes[] = {
        "1kohm_to_gnd", "100kohm_to_gnd", "three_state",
};

static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
                                      const struct iio_chan_spec *chan)
{
        struct dac5571_data *data = iio_priv(indio_dev);

        return data->powerdown_mode[chan->channel];
}

static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
                                      const struct iio_chan_spec *chan,
                                      unsigned int mode)
{
        struct dac5571_data *data = iio_priv(indio_dev);
        int ret = 0;

        if (data->powerdown_mode[chan->channel] == mode)
                return 0;

        mutex_lock(&data->lock);
        if (data->powerdown[chan->channel]) {
                ret = data->dac5571_pwrdwn(data, chan->channel,
                                           DAC5571_POWERDOWN(mode));
                if (ret)
                        goto out;
        }
        data->powerdown_mode[chan->channel] = mode;

 out:
        mutex_unlock(&data->lock);

        return ret;
}

static const struct iio_enum dac5571_powerdown_mode = {
        .items = dac5571_powerdown_modes,
        .num_items = ARRAY_SIZE(dac5571_powerdown_modes),
        .get = dac5571_get_powerdown_mode,
        .set = dac5571_set_powerdown_mode,
};

static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
                                      uintptr_t private,
                                      const struct iio_chan_spec *chan,
                                      char *buf)
{
        struct dac5571_data *data = iio_priv(indio_dev);

        return sysfs_emit(buf, "%d\n", data->powerdown[chan->channel]);
}

static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
                                       uintptr_t private,
                                       const struct iio_chan_spec *chan,
                                       const char *buf, size_t len)
{
        struct dac5571_data *data = iio_priv(indio_dev);
        bool powerdown;
        int ret;

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

        if (data->powerdown[chan->channel] == powerdown)
                return len;

        mutex_lock(&data->lock);
        if (powerdown)
                ret = data->dac5571_pwrdwn(data, chan->channel,
                            DAC5571_POWERDOWN(data->powerdown_mode[chan->channel]));
        else
                ret = data->dac5571_cmd(data, chan->channel,
                                data->val[chan->channel]);
        if (ret)
                goto out;

        data->powerdown[chan->channel] = powerdown;

 out:
        mutex_unlock(&data->lock);

        return ret ? ret : len;
}


static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
        {
                .name      = "powerdown",
                .read      = dac5571_read_powerdown,
                .write     = dac5571_write_powerdown,
                .shared    = IIO_SEPARATE,
        },
        IIO_ENUM("powerdown_mode", IIO_SEPARATE, &dac5571_powerdown_mode),
        IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
        { }
};

#define dac5571_CHANNEL(chan, name) {                           \
        .type = IIO_VOLTAGE,                                    \
        .channel = (chan),                                      \
        .address = (chan),                                      \
        .indexed = true,                                        \
        .output = true,                                         \
        .datasheet_name = name,                                 \
        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
        .ext_info = dac5571_ext_info,                           \
}

static const struct iio_chan_spec dac5571_channels[] = {
        dac5571_CHANNEL(0, "A"),
        dac5571_CHANNEL(1, "B"),
        dac5571_CHANNEL(2, "C"),
        dac5571_CHANNEL(3, "D"),
};

static int dac5571_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int *val, int *val2, long mask)
{
        struct dac5571_data *data = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                *val = data->val[chan->channel];
                return IIO_VAL_INT;

        case IIO_CHAN_INFO_SCALE:
                ret = regulator_get_voltage(data->vref);
                if (ret < 0)
                        return ret;

                *val = ret / 1000;
                *val2 = data->spec->resolution;
                return IIO_VAL_FRACTIONAL_LOG2;

        default:
                return -EINVAL;
        }
}

static int dac5571_write_raw(struct iio_dev *indio_dev,
                             struct iio_chan_spec const *chan,
                             int val, int val2, long mask)
{
        struct dac5571_data *data = iio_priv(indio_dev);
        int ret;

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                if (data->val[chan->channel] == val)
                        return 0;

                if (val >= (1 << data->spec->resolution) || val < 0)
                        return -EINVAL;

                if (data->powerdown[chan->channel])
                        return -EBUSY;

                mutex_lock(&data->lock);
                ret = data->dac5571_cmd(data, chan->channel, val);
                if (ret == 0)
                        data->val[chan->channel] = val;
                mutex_unlock(&data->lock);
                return ret;

        default:
                return -EINVAL;
        }
}

static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
                                     struct iio_chan_spec const *chan,
                                     long mask)
{
        return IIO_VAL_INT;
}

static const struct iio_info dac5571_info = {
        .read_raw = dac5571_read_raw,
        .write_raw = dac5571_write_raw,
        .write_raw_get_fmt = dac5571_write_raw_get_fmt,
};

static int dac5571_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct device *dev = &client->dev;
        const struct dac5571_spec *spec;
        struct dac5571_data *data;
        struct iio_dev *indio_dev;
        int ret, i;

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

        data = iio_priv(indio_dev);
        i2c_set_clientdata(client, indio_dev);
        data->client = client;

        indio_dev->info = &dac5571_info;
        indio_dev->name = id->name;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = dac5571_channels;

        spec = i2c_get_match_data(client);

        indio_dev->num_channels = spec->num_channels;
        data->spec = spec;

        data->vref = devm_regulator_get(dev, "vref");
        if (IS_ERR(data->vref))
                return PTR_ERR(data->vref);

        ret = regulator_enable(data->vref);
        if (ret < 0)
                return ret;

        mutex_init(&data->lock);

        switch (spec->num_channels) {
        case 1:
                data->dac5571_cmd = dac5571_cmd_single;
                data->dac5571_pwrdwn = dac5571_pwrdwn_single;
                break;
        case 4:
                data->dac5571_cmd = dac5571_cmd_quad;
                data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
                break;
        default:
                ret = -EINVAL;
                goto err;
        }

        for (i = 0; i < spec->num_channels; i++) {
                ret = data->dac5571_cmd(data, i, 0);
                if (ret) {
                        dev_err(dev, "failed to initialize channel %d to 0\n", i);
                        goto err;
                }
        }

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

        return 0;

 err:
        regulator_disable(data->vref);
        return ret;
}

static void dac5571_remove(struct i2c_client *i2c)
{
        struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
        struct dac5571_data *data = iio_priv(indio_dev);

        iio_device_unregister(indio_dev);
        regulator_disable(data->vref);
}

static const struct of_device_id dac5571_of_id[] = {
        {.compatible = "ti,dac081c081", .data = &dac5571_spec[single_8bit] },
        {.compatible = "ti,dac121c081", .data = &dac5571_spec[single_12bit] },
        {.compatible = "ti,dac5571", .data = &dac5571_spec[single_8bit] },
        {.compatible = "ti,dac6571", .data = &dac5571_spec[single_10bit] },
        {.compatible = "ti,dac7571", .data = &dac5571_spec[single_12bit] },
        {.compatible = "ti,dac5574", .data = &dac5571_spec[quad_8bit] },
        {.compatible = "ti,dac6574", .data = &dac5571_spec[quad_10bit] },
        {.compatible = "ti,dac7574", .data = &dac5571_spec[quad_12bit] },
        {.compatible = "ti,dac5573", .data = &dac5571_spec[quad_8bit] },
        {.compatible = "ti,dac6573", .data = &dac5571_spec[quad_10bit] },
        {.compatible = "ti,dac7573", .data = &dac5571_spec[quad_12bit] },
        { }
};
MODULE_DEVICE_TABLE(of, dac5571_of_id);

static const struct i2c_device_id dac5571_id[] = {
        {"dac081c081", (kernel_ulong_t)&dac5571_spec[single_8bit] },
        {"dac121c081", (kernel_ulong_t)&dac5571_spec[single_12bit] },
        {"dac5571", (kernel_ulong_t)&dac5571_spec[single_8bit] },
        {"dac6571", (kernel_ulong_t)&dac5571_spec[single_10bit] },
        {"dac7571", (kernel_ulong_t)&dac5571_spec[single_12bit] },
        {"dac5574", (kernel_ulong_t)&dac5571_spec[quad_8bit] },
        {"dac6574", (kernel_ulong_t)&dac5571_spec[quad_10bit] },
        {"dac7574", (kernel_ulong_t)&dac5571_spec[quad_12bit] },
        {"dac5573", (kernel_ulong_t)&dac5571_spec[quad_8bit] },
        {"dac6573", (kernel_ulong_t)&dac5571_spec[quad_10bit] },
        {"dac7573", (kernel_ulong_t)&dac5571_spec[quad_12bit] },
        { }
};
MODULE_DEVICE_TABLE(i2c, dac5571_id);

static struct i2c_driver dac5571_driver = {
        .driver = {
                   .name = "ti-dac5571",
                   .of_match_table = dac5571_of_id,
        },
        .probe = dac5571_probe,
        .remove   = dac5571_remove,
        .id_table = dac5571_id,
};
module_i2c_driver(dac5571_driver);

MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
MODULE_LICENSE("GPL v2");