linux/drivers/iio/dac/ti-dac5571.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver
   4 *
   5 * Copyright (C) 2018 Prevas A/S
   6 *
   7 * https://www.ti.com/lit/ds/symlink/dac5571.pdf
   8 * https://www.ti.com/lit/ds/symlink/dac6571.pdf
   9 * https://www.ti.com/lit/ds/symlink/dac7571.pdf
  10 * https://www.ti.com/lit/ds/symlink/dac5574.pdf
  11 * https://www.ti.com/lit/ds/symlink/dac6574.pdf
  12 * https://www.ti.com/lit/ds/symlink/dac7574.pdf
  13 * https://www.ti.com/lit/ds/symlink/dac5573.pdf
  14 * https://www.ti.com/lit/ds/symlink/dac6573.pdf
  15 * https://www.ti.com/lit/ds/symlink/dac7573.pdf
  16 */
  17
  18#include <linux/iio/iio.h>
  19#include <linux/i2c.h>
  20#include <linux/module.h>
  21#include <linux/mod_devicetable.h>
  22#include <linux/regulator/consumer.h>
  23
  24enum chip_id {
  25        single_8bit, single_10bit, single_12bit,
  26        quad_8bit, quad_10bit, quad_12bit
  27};
  28
  29struct dac5571_spec {
  30        u8 num_channels;
  31        u8 resolution;
  32};
  33
  34static const struct dac5571_spec dac5571_spec[] = {
  35        [single_8bit]  = {.num_channels = 1, .resolution =  8},
  36        [single_10bit] = {.num_channels = 1, .resolution = 10},
  37        [single_12bit] = {.num_channels = 1, .resolution = 12},
  38        [quad_8bit]    = {.num_channels = 4, .resolution =  8},
  39        [quad_10bit]   = {.num_channels = 4, .resolution = 10},
  40        [quad_12bit]   = {.num_channels = 4, .resolution = 12},
  41};
  42
  43struct dac5571_data {
  44        struct i2c_client *client;
  45        int id;
  46        struct mutex lock;
  47        struct regulator *vref;
  48        u16 val[4];
  49        bool powerdown[4];
  50        u8 powerdown_mode[4];
  51        struct dac5571_spec const *spec;
  52        int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
  53        int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
  54        u8 buf[3] ____cacheline_aligned;
  55};
  56
  57#define DAC5571_POWERDOWN(mode)         ((mode) + 1)
  58#define DAC5571_POWERDOWN_FLAG          BIT(0)
  59#define DAC5571_CHANNEL_SELECT          1
  60#define DAC5571_LOADMODE_DIRECT         BIT(4)
  61#define DAC5571_SINGLE_PWRDWN_BITS      4
  62#define DAC5571_QUAD_PWRDWN_BITS        6
  63
  64static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
  65{
  66        unsigned int shift;
  67
  68        shift = 12 - data->spec->resolution;
  69        data->buf[1] = val << shift;
  70        data->buf[0] = val >> (8 - shift);
  71
  72        if (i2c_master_send(data->client, data->buf, 2) != 2)
  73                return -EIO;
  74
  75        return 0;
  76}
  77
  78static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
  79{
  80        unsigned int shift;
  81
  82        shift = 16 - data->spec->resolution;
  83        data->buf[2] = val << shift;
  84        data->buf[1] = (val >> (8 - shift));
  85        data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
  86                       DAC5571_LOADMODE_DIRECT;
  87
  88        if (i2c_master_send(data->client, data->buf, 3) != 3)
  89                return -EIO;
  90
  91        return 0;
  92}
  93
  94static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
  95{
  96        data->buf[1] = 0;
  97        data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
  98
  99        if (i2c_master_send(data->client, data->buf, 2) != 2)
 100                return -EIO;
 101
 102        return 0;
 103}
 104
 105static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
 106{
 107        data->buf[2] = 0;
 108        data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
 109        data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
 110                       DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
 111
 112        if (i2c_master_send(data->client, data->buf, 3) != 3)
 113                return -EIO;
 114
 115        return 0;
 116}
 117
 118static const char *const dac5571_powerdown_modes[] = {
 119        "1kohm_to_gnd", "100kohm_to_gnd", "three_state",
 120};
 121
 122static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
 123                                      const struct iio_chan_spec *chan)
 124{
 125        struct dac5571_data *data = iio_priv(indio_dev);
 126
 127        return data->powerdown_mode[chan->channel];
 128}
 129
 130static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
 131                                      const struct iio_chan_spec *chan,
 132                                      unsigned int mode)
 133{
 134        struct dac5571_data *data = iio_priv(indio_dev);
 135        int ret = 0;
 136
 137        if (data->powerdown_mode[chan->channel] == mode)
 138                return 0;
 139
 140        mutex_lock(&data->lock);
 141        if (data->powerdown[chan->channel]) {
 142                ret = data->dac5571_pwrdwn(data, chan->channel,
 143                                           DAC5571_POWERDOWN(mode));
 144                if (ret)
 145                        goto out;
 146        }
 147        data->powerdown_mode[chan->channel] = mode;
 148
 149 out:
 150        mutex_unlock(&data->lock);
 151
 152        return ret;
 153}
 154
 155static const struct iio_enum dac5571_powerdown_mode = {
 156        .items = dac5571_powerdown_modes,
 157        .num_items = ARRAY_SIZE(dac5571_powerdown_modes),
 158        .get = dac5571_get_powerdown_mode,
 159        .set = dac5571_set_powerdown_mode,
 160};
 161
 162static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
 163                                      uintptr_t private,
 164                                      const struct iio_chan_spec *chan,
 165                                      char *buf)
 166{
 167        struct dac5571_data *data = iio_priv(indio_dev);
 168
 169        return sysfs_emit(buf, "%d\n", data->powerdown[chan->channel]);
 170}
 171
 172static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
 173                                       uintptr_t private,
 174                                       const struct iio_chan_spec *chan,
 175                                       const char *buf, size_t len)
 176{
 177        struct dac5571_data *data = iio_priv(indio_dev);
 178        bool powerdown;
 179        int ret;
 180
 181        ret = strtobool(buf, &powerdown);
 182        if (ret)
 183                return ret;
 184
 185        if (data->powerdown[chan->channel] == powerdown)
 186                return len;
 187
 188        mutex_lock(&data->lock);
 189        if (powerdown)
 190                ret = data->dac5571_pwrdwn(data, chan->channel,
 191                            DAC5571_POWERDOWN(data->powerdown_mode[chan->channel]));
 192        else
 193                ret = data->dac5571_cmd(data, chan->channel,
 194                                data->val[chan->channel]);
 195        if (ret)
 196                goto out;
 197
 198        data->powerdown[chan->channel] = powerdown;
 199
 200 out:
 201        mutex_unlock(&data->lock);
 202
 203        return ret ? ret : len;
 204}
 205
 206
 207static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
 208        {
 209                .name      = "powerdown",
 210                .read      = dac5571_read_powerdown,
 211                .write     = dac5571_write_powerdown,
 212                .shared    = IIO_SEPARATE,
 213        },
 214        IIO_ENUM("powerdown_mode", IIO_SEPARATE, &dac5571_powerdown_mode),
 215        IIO_ENUM_AVAILABLE("powerdown_mode", &dac5571_powerdown_mode),
 216        {},
 217};
 218
 219#define dac5571_CHANNEL(chan, name) {                           \
 220        .type = IIO_VOLTAGE,                                    \
 221        .channel = (chan),                                      \
 222        .address = (chan),                                      \
 223        .indexed = true,                                        \
 224        .output = true,                                         \
 225        .datasheet_name = name,                                 \
 226        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 227        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
 228        .ext_info = dac5571_ext_info,                           \
 229}
 230
 231static const struct iio_chan_spec dac5571_channels[] = {
 232        dac5571_CHANNEL(0, "A"),
 233        dac5571_CHANNEL(1, "B"),
 234        dac5571_CHANNEL(2, "C"),
 235        dac5571_CHANNEL(3, "D"),
 236};
 237
 238static int dac5571_read_raw(struct iio_dev *indio_dev,
 239                            struct iio_chan_spec const *chan,
 240                            int *val, int *val2, long mask)
 241{
 242        struct dac5571_data *data = iio_priv(indio_dev);
 243        int ret;
 244
 245        switch (mask) {
 246        case IIO_CHAN_INFO_RAW:
 247                *val = data->val[chan->channel];
 248                return IIO_VAL_INT;
 249
 250        case IIO_CHAN_INFO_SCALE:
 251                ret = regulator_get_voltage(data->vref);
 252                if (ret < 0)
 253                        return ret;
 254
 255                *val = ret / 1000;
 256                *val2 = data->spec->resolution;
 257                return IIO_VAL_FRACTIONAL_LOG2;
 258
 259        default:
 260                return -EINVAL;
 261        }
 262}
 263
 264static int dac5571_write_raw(struct iio_dev *indio_dev,
 265                             struct iio_chan_spec const *chan,
 266                             int val, int val2, long mask)
 267{
 268        struct dac5571_data *data = iio_priv(indio_dev);
 269        int ret;
 270
 271        switch (mask) {
 272        case IIO_CHAN_INFO_RAW:
 273                if (data->val[chan->channel] == val)
 274                        return 0;
 275
 276                if (val >= (1 << data->spec->resolution) || val < 0)
 277                        return -EINVAL;
 278
 279                if (data->powerdown[chan->channel])
 280                        return -EBUSY;
 281
 282                mutex_lock(&data->lock);
 283                ret = data->dac5571_cmd(data, chan->channel, val);
 284                if (ret == 0)
 285                        data->val[chan->channel] = val;
 286                mutex_unlock(&data->lock);
 287                return ret;
 288
 289        default:
 290                return -EINVAL;
 291        }
 292}
 293
 294static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
 295                                     struct iio_chan_spec const *chan,
 296                                     long mask)
 297{
 298        return IIO_VAL_INT;
 299}
 300
 301static const struct iio_info dac5571_info = {
 302        .read_raw = dac5571_read_raw,
 303        .write_raw = dac5571_write_raw,
 304        .write_raw_get_fmt = dac5571_write_raw_get_fmt,
 305};
 306
 307static int dac5571_probe(struct i2c_client *client,
 308                         const struct i2c_device_id *id)
 309{
 310        struct device *dev = &client->dev;
 311        const struct dac5571_spec *spec;
 312        struct dac5571_data *data;
 313        struct iio_dev *indio_dev;
 314        int ret, i;
 315
 316        indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 317        if (!indio_dev)
 318                return -ENOMEM;
 319
 320        data = iio_priv(indio_dev);
 321        i2c_set_clientdata(client, indio_dev);
 322        data->client = client;
 323
 324        indio_dev->info = &dac5571_info;
 325        indio_dev->name = id->name;
 326        indio_dev->modes = INDIO_DIRECT_MODE;
 327        indio_dev->channels = dac5571_channels;
 328
 329        spec = &dac5571_spec[id->driver_data];
 330        indio_dev->num_channels = spec->num_channels;
 331        data->spec = spec;
 332
 333        data->vref = devm_regulator_get(dev, "vref");
 334        if (IS_ERR(data->vref))
 335                return PTR_ERR(data->vref);
 336
 337        ret = regulator_enable(data->vref);
 338        if (ret < 0)
 339                return ret;
 340
 341        mutex_init(&data->lock);
 342
 343        switch (spec->num_channels) {
 344        case 1:
 345                data->dac5571_cmd = dac5571_cmd_single;
 346                data->dac5571_pwrdwn = dac5571_pwrdwn_single;
 347                break;
 348        case 4:
 349                data->dac5571_cmd = dac5571_cmd_quad;
 350                data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
 351                break;
 352        default:
 353                goto err;
 354        }
 355
 356        for (i = 0; i < spec->num_channels; i++) {
 357                ret = data->dac5571_cmd(data, i, 0);
 358                if (ret) {
 359                        dev_err(dev, "failed to initialize channel %d to 0\n", i);
 360                        goto err;
 361                }
 362        }
 363
 364        ret = iio_device_register(indio_dev);
 365        if (ret)
 366                goto err;
 367
 368        return 0;
 369
 370 err:
 371        regulator_disable(data->vref);
 372        return ret;
 373}
 374
 375static int dac5571_remove(struct i2c_client *i2c)
 376{
 377        struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
 378        struct dac5571_data *data = iio_priv(indio_dev);
 379
 380        iio_device_unregister(indio_dev);
 381        regulator_disable(data->vref);
 382
 383        return 0;
 384}
 385
 386static const struct of_device_id dac5571_of_id[] = {
 387        {.compatible = "ti,dac5571"},
 388        {.compatible = "ti,dac6571"},
 389        {.compatible = "ti,dac7571"},
 390        {.compatible = "ti,dac5574"},
 391        {.compatible = "ti,dac6574"},
 392        {.compatible = "ti,dac7574"},
 393        {.compatible = "ti,dac5573"},
 394        {.compatible = "ti,dac6573"},
 395        {.compatible = "ti,dac7573"},
 396        {}
 397};
 398MODULE_DEVICE_TABLE(of, dac5571_of_id);
 399
 400static const struct i2c_device_id dac5571_id[] = {
 401        {"dac5571", single_8bit},
 402        {"dac6571", single_10bit},
 403        {"dac7571", single_12bit},
 404        {"dac5574", quad_8bit},
 405        {"dac6574", quad_10bit},
 406        {"dac7574", quad_12bit},
 407        {"dac5573", quad_8bit},
 408        {"dac6573", quad_10bit},
 409        {"dac7573", quad_12bit},
 410        {}
 411};
 412MODULE_DEVICE_TABLE(i2c, dac5571_id);
 413
 414static struct i2c_driver dac5571_driver = {
 415        .driver = {
 416                   .name = "ti-dac5571",
 417                   .of_match_table = dac5571_of_id,
 418        },
 419        .probe    = dac5571_probe,
 420        .remove   = dac5571_remove,
 421        .id_table = dac5571_id,
 422};
 423module_i2c_driver(dac5571_driver);
 424
 425MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
 426MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
 427MODULE_LICENSE("GPL v2");
 428