drivers/iio/dac/ti-dac5571.c

   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
  24 enum chip_id {
  25         single_8bit, single_10bit, single_12bit,
  26         quad_8bit, quad_10bit, quad_12bit
  27 };
  28
  29 struct dac5571_spec {
  30         u8 num_channels;
  31         u8 resolution;
  32 };
  33
  34 static 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
  43 struct 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
  64 static 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
  78 static 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
  94 static 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
 105 static 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
 118 static const char *const dac5571_powerdown_modes[] = {
 119         "1kohm_to_gnd", "100kohm_to_gnd", "three_state",
 120 };
 121
 122 static 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
 130 static 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
 155 static 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
 162 static 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
 172 static 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
 207 static 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
 231 static 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
 238 static 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
 264 static 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
 294 static 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
 301 static 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
 307 static 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
 375 static 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
 386 static 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 };
 398 MODULE_DEVICE_TABLE(of, dac5571_of_id);
 399
 400 static 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 };
 412 MODULE_DEVICE_TABLE(i2c, dac5571_id);
 413
 414 static 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 };
 423 module_i2c_driver(dac5571_driver);
 424
 425 MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
 426 MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
 427 MODULE_LICENSE("GPL v2");