drivers/iio/dac/ad5064.c

   1 /*
   2  * AD5024, AD5025, AD5044, AD5045, AD5064, AD5064-1, AD5065, AD5628, AD5629R,
   3  * AD5648, AD5666, AD5668, AD5669R Digital to analog converters driver
   4  *
   5  * Copyright 2011 Analog Devices Inc.
   6  *
   7  * Licensed under the GPL-2.
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/err.h>
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/i2c.h>
  16 #include <linux/slab.h>
  17 #include <linux/sysfs.h>
  18 #include <linux/regulator/consumer.h>
  19 #include <asm/unaligned.h>
  20
  21 #include <linux/iio/iio.h>
  22 #include <linux/iio/sysfs.h>
  23
  24 #define AD5064_MAX_DAC_CHANNELS                 8
  25 #define AD5064_MAX_VREFS                        4
  26
  27 #define AD5064_ADDR(x)                          ((x) << 20)
  28 #define AD5064_CMD(x)                           ((x) << 24)
  29
  30 #define AD5064_ADDR_DAC(chan)                   (chan)
  31 #define AD5064_ADDR_ALL_DAC                     0xF
  32
  33 #define AD5064_CMD_WRITE_INPUT_N                0x0
  34 #define AD5064_CMD_UPDATE_DAC_N                 0x1
  35 #define AD5064_CMD_WRITE_INPUT_N_UPDATE_ALL     0x2
  36 #define AD5064_CMD_WRITE_INPUT_N_UPDATE_N       0x3
  37 #define AD5064_CMD_POWERDOWN_DAC                0x4
  38 #define AD5064_CMD_CLEAR                        0x5
  39 #define AD5064_CMD_LDAC_MASK                    0x6
  40 #define AD5064_CMD_RESET                        0x7
  41 #define AD5064_CMD_CONFIG                       0x8
  42
  43 #define AD5064_CONFIG_DAISY_CHAIN_ENABLE        BIT(1)
  44 #define AD5064_CONFIG_INT_VREF_ENABLE           BIT(0)
  45
  46 #define AD5064_LDAC_PWRDN_NONE                  0x0
  47 #define AD5064_LDAC_PWRDN_1K                    0x1
  48 #define AD5064_LDAC_PWRDN_100K                  0x2
  49 #define AD5064_LDAC_PWRDN_3STATE                0x3
  50
  51 /**
  52  * struct ad5064_chip_info - chip specific information
  53  * @shared_vref:        whether the vref supply is shared between channels
  54  * @internal_vref:      internal reference voltage. 0 if the chip has no internal
  55  *                      vref.
  56  * @channel:            channel specification
  57  * @num_channels:       number of channels
  58  */
  59
  60 struct ad5064_chip_info {
  61         bool shared_vref;
  62         unsigned long internal_vref;
  63         const struct iio_chan_spec *channels;
  64         unsigned int num_channels;
  65 };
  66
  67 struct ad5064_state;
  68
  69 typedef int (*ad5064_write_func)(struct ad5064_state *st, unsigned int cmd,
  70                 unsigned int addr, unsigned int val);
  71
  72 /**
  73  * struct ad5064_state - driver instance specific data
  74  * @dev:                the device for this driver instance
  75  * @chip_info:          chip model specific constants, available modes etc
  76  * @vref_reg:           vref supply regulators
  77  * @pwr_down:           whether channel is powered down
  78  * @pwr_down_mode:      channel's current power down mode
  79  * @dac_cache:          current DAC raw value (chip does not support readback)
  80  * @use_internal_vref:  set to true if the internal reference voltage should be
  81  *                      used.
  82  * @write:              register write callback
  83  * @data:               i2c/spi transfer buffers
  84  */
  85
  86 struct ad5064_state {
  87         struct device                   *dev;
  88         const struct ad5064_chip_info   *chip_info;
  89         struct regulator_bulk_data      vref_reg[AD5064_MAX_VREFS];
  90         bool                            pwr_down[AD5064_MAX_DAC_CHANNELS];
  91         u8                              pwr_down_mode[AD5064_MAX_DAC_CHANNELS];
  92         unsigned int                    dac_cache[AD5064_MAX_DAC_CHANNELS];
  93         bool                            use_internal_vref;
  94
  95         ad5064_write_func               write;
  96
  97         /*
  98          * DMA (thus cache coherency maintenance) requires the
  99          * transfer buffers to live in their own cache lines.
 100          */
 101         union {
 102                 u8 i2c[3];
 103                 __be32 spi;
 104         } data ____cacheline_aligned;
 105 };
 106
 107 enum ad5064_type {
 108         ID_AD5024,
 109         ID_AD5025,
 110         ID_AD5044,
 111         ID_AD5045,
 112         ID_AD5064,
 113         ID_AD5064_1,
 114         ID_AD5065,
 115         ID_AD5628_1,
 116         ID_AD5628_2,
 117         ID_AD5648_1,
 118         ID_AD5648_2,
 119         ID_AD5666_1,
 120         ID_AD5666_2,
 121         ID_AD5668_1,
 122         ID_AD5668_2,
 123 };
 124
 125 static int ad5064_write(struct ad5064_state *st, unsigned int cmd,
 126         unsigned int addr, unsigned int val, unsigned int shift)
 127 {
 128         val <<= shift;
 129
 130         return st->write(st, cmd, addr, val);
 131 }
 132
 133 static int ad5064_sync_powerdown_mode(struct ad5064_state *st,
 134         unsigned int channel)
 135 {
 136         unsigned int val;
 137         int ret;
 138
 139         val = (0x1 << channel);
 140
 141         if (st->pwr_down[channel])
 142                 val |= st->pwr_down_mode[channel] << 8;
 143
 144         ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, 0, val, 0);
 145
 146         return ret;
 147 }
 148
 149 static const char * const ad5064_powerdown_modes[] = {
 150         "1kohm_to_gnd",
 151         "100kohm_to_gnd",
 152         "three_state",
 153 };
 154
 155 static int ad5064_get_powerdown_mode(struct iio_dev *indio_dev,
 156         const struct iio_chan_spec *chan)
 157 {
 158         struct ad5064_state *st = iio_priv(indio_dev);
 159
 160         return st->pwr_down_mode[chan->channel] - 1;
 161 }
 162
 163 static int ad5064_set_powerdown_mode(struct iio_dev *indio_dev,
 164         const struct iio_chan_spec *chan, unsigned int mode)
 165 {
 166         struct ad5064_state *st = iio_priv(indio_dev);
 167         int ret;
 168
 169         mutex_lock(&indio_dev->mlock);
 170         st->pwr_down_mode[chan->channel] = mode + 1;
 171
 172         ret = ad5064_sync_powerdown_mode(st, chan->channel);
 173         mutex_unlock(&indio_dev->mlock);
 174
 175         return ret;
 176 }
 177
 178 static const struct iio_enum ad5064_powerdown_mode_enum = {
 179         .items = ad5064_powerdown_modes,
 180         .num_items = ARRAY_SIZE(ad5064_powerdown_modes),
 181         .get = ad5064_get_powerdown_mode,
 182         .set = ad5064_set_powerdown_mode,
 183 };
 184
 185 static ssize_t ad5064_read_dac_powerdown(struct iio_dev *indio_dev,
 186         uintptr_t private, const struct iio_chan_spec *chan, char *buf)
 187 {
 188         struct ad5064_state *st = iio_priv(indio_dev);
 189
 190         return sprintf(buf, "%d\n", st->pwr_down[chan->channel]);
 191 }
 192
 193 static ssize_t ad5064_write_dac_powerdown(struct iio_dev *indio_dev,
 194          uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
 195          size_t len)
 196 {
 197         struct ad5064_state *st = iio_priv(indio_dev);
 198         bool pwr_down;
 199         int ret;
 200
 201         ret = strtobool(buf, &pwr_down);
 202         if (ret)
 203                 return ret;
 204
 205         mutex_lock(&indio_dev->mlock);
 206         st->pwr_down[chan->channel] = pwr_down;
 207
 208         ret = ad5064_sync_powerdown_mode(st, chan->channel);
 209         mutex_unlock(&indio_dev->mlock);
 210         return ret ? ret : len;
 211 }
 212
 213 static int ad5064_get_vref(struct ad5064_state *st,
 214         struct iio_chan_spec const *chan)
 215 {
 216         unsigned int i;
 217
 218         if (st->use_internal_vref)
 219                 return st->chip_info->internal_vref;
 220
 221         i = st->chip_info->shared_vref ? 0 : chan->channel;
 222         return regulator_get_voltage(st->vref_reg[i].consumer);
 223 }
 224
 225 static int ad5064_read_raw(struct iio_dev *indio_dev,
 226                            struct iio_chan_spec const *chan,
 227                            int *val,
 228                            int *val2,
 229                            long m)
 230 {
 231         struct ad5064_state *st = iio_priv(indio_dev);
 232         int scale_uv;
 233
 234         switch (m) {
 235         case IIO_CHAN_INFO_RAW:
 236                 *val = st->dac_cache[chan->channel];
 237                 return IIO_VAL_INT;
 238         case IIO_CHAN_INFO_SCALE:
 239                 scale_uv = ad5064_get_vref(st, chan);
 240                 if (scale_uv < 0)
 241                         return scale_uv;
 242
 243                 scale_uv = (scale_uv * 100) >> chan->scan_type.realbits;
 244                 *val =  scale_uv / 100000;
 245                 *val2 = (scale_uv % 100000) * 10;
 246                 return IIO_VAL_INT_PLUS_MICRO;
 247         default:
 248                 break;
 249         }
 250         return -EINVAL;
 251 }
 252
 253 static int ad5064_write_raw(struct iio_dev *indio_dev,
 254         struct iio_chan_spec const *chan, int val, int val2, long mask)
 255 {
 256         struct ad5064_state *st = iio_priv(indio_dev);
 257         int ret;
 258
 259         switch (mask) {
 260         case IIO_CHAN_INFO_RAW:
 261                 if (val > (1 << chan->scan_type.realbits) || val < 0)
 262                         return -EINVAL;
 263
 264                 mutex_lock(&indio_dev->mlock);
 265                 ret = ad5064_write(st, AD5064_CMD_WRITE_INPUT_N_UPDATE_N,
 266                                 chan->address, val, chan->scan_type.shift);
 267                 if (ret == 0)
 268                         st->dac_cache[chan->channel] = val;
 269                 mutex_unlock(&indio_dev->mlock);
 270                 break;
 271         default:
 272                 ret = -EINVAL;
 273         }
 274
 275         return ret;
 276 }
 277
 278 static const struct iio_info ad5064_info = {
 279         .read_raw = ad5064_read_raw,
 280         .write_raw = ad5064_write_raw,
 281         .driver_module = THIS_MODULE,
 282 };
 283
 284 static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
 285         {
 286                 .name = "powerdown",
 287                 .read = ad5064_read_dac_powerdown,
 288                 .write = ad5064_write_dac_powerdown,
 289         },
 290         IIO_ENUM("powerdown_mode", false, &ad5064_powerdown_mode_enum),
 291         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5064_powerdown_mode_enum),
 292         { },
 293 };
 294
 295 #define AD5064_CHANNEL(chan, bits) {                            \
 296         .type = IIO_VOLTAGE,                                    \
 297         .indexed = 1,                                           \
 298         .output = 1,                                            \
 299         .channel = (chan),                                      \
 300         .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |           \
 301         IIO_CHAN_INFO_SCALE_SEPARATE_BIT,                       \
 302         .address = AD5064_ADDR_DAC(chan),                       \
 303         .scan_type = IIO_ST('u', (bits), 16, 20 - (bits)),      \
 304         .ext_info = ad5064_ext_info,                            \
 305 }
 306
 307 #define DECLARE_AD5064_CHANNELS(name, bits) \
 308 const struct iio_chan_spec name[] = { \
 309         AD5064_CHANNEL(0, bits), \
 310         AD5064_CHANNEL(1, bits), \
 311         AD5064_CHANNEL(2, bits), \
 312         AD5064_CHANNEL(3, bits), \
 313         AD5064_CHANNEL(4, bits), \
 314         AD5064_CHANNEL(5, bits), \
 315         AD5064_CHANNEL(6, bits), \
 316         AD5064_CHANNEL(7, bits), \
 317 }
 318
 319 static DECLARE_AD5064_CHANNELS(ad5024_channels, 12);
 320 static DECLARE_AD5064_CHANNELS(ad5044_channels, 14);
 321 static DECLARE_AD5064_CHANNELS(ad5064_channels, 16);
 322
 323 static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
 324         [ID_AD5024] = {
 325                 .shared_vref = false,
 326                 .channels = ad5024_channels,
 327                 .num_channels = 4,
 328         },
 329         [ID_AD5025] = {
 330                 .shared_vref = false,
 331                 .channels = ad5024_channels,
 332                 .num_channels = 2,
 333         },
 334         [ID_AD5044] = {
 335                 .shared_vref = false,
 336                 .channels = ad5044_channels,
 337                 .num_channels = 4,
 338         },
 339         [ID_AD5045] = {
 340                 .shared_vref = false,
 341                 .channels = ad5044_channels,
 342                 .num_channels = 2,
 343         },
 344         [ID_AD5064] = {
 345                 .shared_vref = false,
 346                 .channels = ad5064_channels,
 347                 .num_channels = 4,
 348         },
 349         [ID_AD5064_1] = {
 350                 .shared_vref = true,
 351                 .channels = ad5064_channels,
 352                 .num_channels = 4,
 353         },
 354         [ID_AD5065] = {
 355                 .shared_vref = false,
 356                 .channels = ad5064_channels,
 357                 .num_channels = 2,
 358         },
 359         [ID_AD5628_1] = {
 360                 .shared_vref = true,
 361                 .internal_vref = 2500000,
 362                 .channels = ad5024_channels,
 363                 .num_channels = 8,
 364         },
 365         [ID_AD5628_2] = {
 366                 .shared_vref = true,
 367                 .internal_vref = 5000000,
 368                 .channels = ad5024_channels,
 369                 .num_channels = 8,
 370         },
 371         [ID_AD5648_1] = {
 372                 .shared_vref = true,
 373                 .internal_vref = 2500000,
 374                 .channels = ad5044_channels,
 375                 .num_channels = 8,
 376         },
 377         [ID_AD5648_2] = {
 378                 .shared_vref = true,
 379                 .internal_vref = 5000000,
 380                 .channels = ad5044_channels,
 381                 .num_channels = 8,
 382         },
 383         [ID_AD5666_1] = {
 384                 .shared_vref = true,
 385                 .internal_vref = 2500000,
 386                 .channels = ad5064_channels,
 387                 .num_channels = 4,
 388         },
 389         [ID_AD5666_2] = {
 390                 .shared_vref = true,
 391                 .internal_vref = 5000000,
 392                 .channels = ad5064_channels,
 393                 .num_channels = 4,
 394         },
 395         [ID_AD5668_1] = {
 396                 .shared_vref = true,
 397                 .internal_vref = 2500000,
 398                 .channels = ad5064_channels,
 399                 .num_channels = 8,
 400         },
 401         [ID_AD5668_2] = {
 402                 .shared_vref = true,
 403                 .internal_vref = 5000000,
 404                 .channels = ad5064_channels,
 405                 .num_channels = 8,
 406         },
 407 };
 408
 409 static inline unsigned int ad5064_num_vref(struct ad5064_state *st)
 410 {
 411         return st->chip_info->shared_vref ? 1 : st->chip_info->num_channels;
 412 }
 413
 414 static const char * const ad5064_vref_names[] = {
 415         "vrefA",
 416         "vrefB",
 417         "vrefC",
 418         "vrefD",
 419 };
 420
 421 static const char * const ad5064_vref_name(struct ad5064_state *st,
 422         unsigned int vref)
 423 {
 424         return st->chip_info->shared_vref ? "vref" : ad5064_vref_names[vref];
 425 }
 426
 427 static int ad5064_probe(struct device *dev, enum ad5064_type type,
 428                         const char *name, ad5064_write_func write)
 429 {
 430         struct iio_dev *indio_dev;
 431         struct ad5064_state *st;
 432         unsigned int i;
 433         int ret;
 434
 435         indio_dev = iio_device_alloc(sizeof(*st));
 436         if (indio_dev == NULL)
 437                 return  -ENOMEM;
 438
 439         st = iio_priv(indio_dev);
 440         dev_set_drvdata(dev, indio_dev);
 441
 442         st->chip_info = &ad5064_chip_info_tbl[type];
 443         st->dev = dev;
 444         st->write = write;
 445
 446         for (i = 0; i < ad5064_num_vref(st); ++i)
 447                 st->vref_reg[i].supply = ad5064_vref_name(st, i);
 448
 449         ret = regulator_bulk_get(dev, ad5064_num_vref(st),
 450                 st->vref_reg);
 451         if (ret) {
 452                 if (!st->chip_info->internal_vref)
 453                         goto error_free;
 454                 st->use_internal_vref = true;
 455                 ret = ad5064_write(st, AD5064_CMD_CONFIG, 0,
 456                         AD5064_CONFIG_INT_VREF_ENABLE, 0);
 457                 if (ret) {
 458                         dev_err(dev, "Failed to enable internal vref: %d\n",
 459                                 ret);
 460                         goto error_free;
 461                 }
 462         } else {
 463                 ret = regulator_bulk_enable(ad5064_num_vref(st), st->vref_reg);
 464                 if (ret)
 465                         goto error_free_reg;
 466         }
 467
 468         for (i = 0; i < st->chip_info->num_channels; ++i) {
 469                 st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
 470                 st->dac_cache[i] = 0x8000;
 471         }
 472
 473         indio_dev->dev.parent = dev;
 474         indio_dev->name = name;
 475         indio_dev->info = &ad5064_info;
 476         indio_dev->modes = INDIO_DIRECT_MODE;
 477         indio_dev->channels = st->chip_info->channels;
 478         indio_dev->num_channels = st->chip_info->num_channels;
 479
 480         ret = iio_device_register(indio_dev);
 481         if (ret)
 482                 goto error_disable_reg;
 483
 484         return 0;
 485
 486 error_disable_reg:
 487         if (!st->use_internal_vref)
 488                 regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
 489 error_free_reg:
 490         if (!st->use_internal_vref)
 491                 regulator_bulk_free(ad5064_num_vref(st), st->vref_reg);
 492 error_free:
 493         iio_device_free(indio_dev);
 494
 495         return ret;
 496 }
 497
 498 static int ad5064_remove(struct device *dev)
 499 {
 500         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 501         struct ad5064_state *st = iio_priv(indio_dev);
 502
 503         iio_device_unregister(indio_dev);
 504
 505         if (!st->use_internal_vref) {
 506                 regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
 507                 regulator_bulk_free(ad5064_num_vref(st), st->vref_reg);
 508         }
 509
 510         iio_device_free(indio_dev);
 511
 512         return 0;
 513 }
 514
 515 #if IS_ENABLED(CONFIG_SPI_MASTER)
 516
 517 static int ad5064_spi_write(struct ad5064_state *st, unsigned int cmd,
 518         unsigned int addr, unsigned int val)
 519 {
 520         struct spi_device *spi = to_spi_device(st->dev);
 521
 522         st->data.spi = cpu_to_be32(AD5064_CMD(cmd) | AD5064_ADDR(addr) | val);
 523         return spi_write(spi, &st->data.spi, sizeof(st->data.spi));
 524 }
 525
 526 static int ad5064_spi_probe(struct spi_device *spi)
 527 {
 528         const struct spi_device_id *id = spi_get_device_id(spi);
 529
 530         return ad5064_probe(&spi->dev, id->driver_data, id->name,
 531                                 ad5064_spi_write);
 532 }
 533
 534 static int ad5064_spi_remove(struct spi_device *spi)
 535 {
 536         return ad5064_remove(&spi->dev);
 537 }
 538
 539 static const struct spi_device_id ad5064_spi_ids[] = {
 540         {"ad5024", ID_AD5024},
 541         {"ad5025", ID_AD5025},
 542         {"ad5044", ID_AD5044},
 543         {"ad5045", ID_AD5045},
 544         {"ad5064", ID_AD5064},
 545         {"ad5064-1", ID_AD5064_1},
 546         {"ad5065", ID_AD5065},
 547         {"ad5628-1", ID_AD5628_1},
 548         {"ad5628-2", ID_AD5628_2},
 549         {"ad5648-1", ID_AD5648_1},
 550         {"ad5648-2", ID_AD5648_2},
 551         {"ad5666-1", ID_AD5666_1},
 552         {"ad5666-2", ID_AD5666_2},
 553         {"ad5668-1", ID_AD5668_1},
 554         {"ad5668-2", ID_AD5668_2},
 555         {"ad5668-3", ID_AD5668_2}, /* similar enough to ad5668-2 */
 556         {}
 557 };
 558 MODULE_DEVICE_TABLE(spi, ad5064_spi_ids);
 559
 560 static struct spi_driver ad5064_spi_driver = {
 561         .driver = {
 562                    .name = "ad5064",
 563                    .owner = THIS_MODULE,
 564         },
 565         .probe = ad5064_spi_probe,
 566         .remove = ad5064_spi_remove,
 567         .id_table = ad5064_spi_ids,
 568 };
 569
 570 static int __init ad5064_spi_register_driver(void)
 571 {
 572         return spi_register_driver(&ad5064_spi_driver);
 573 }
 574
 575 static void ad5064_spi_unregister_driver(void)
 576 {
 577         spi_unregister_driver(&ad5064_spi_driver);
 578 }
 579
 580 #else
 581
 582 static inline int ad5064_spi_register_driver(void) { return 0; }
 583 static inline void ad5064_spi_unregister_driver(void) { }
 584
 585 #endif
 586
 587 #if IS_ENABLED(CONFIG_I2C)
 588
 589 static int ad5064_i2c_write(struct ad5064_state *st, unsigned int cmd,
 590         unsigned int addr, unsigned int val)
 591 {
 592         struct i2c_client *i2c = to_i2c_client(st->dev);
 593
 594         st->data.i2c[0] = (cmd << 4) | addr;
 595         put_unaligned_be16(val, &st->data.i2c[1]);
 596         return i2c_master_send(i2c, st->data.i2c, 3);
 597 }
 598
 599 static int ad5064_i2c_probe(struct i2c_client *i2c,
 600         const struct i2c_device_id *id)
 601 {
 602         return ad5064_probe(&i2c->dev, id->driver_data, id->name,
 603                                                 ad5064_i2c_write);
 604 }
 605
 606 static int ad5064_i2c_remove(struct i2c_client *i2c)
 607 {
 608         return ad5064_remove(&i2c->dev);
 609 }
 610
 611 static const struct i2c_device_id ad5064_i2c_ids[] = {
 612         {"ad5629-1", ID_AD5628_1},
 613         {"ad5629-2", ID_AD5628_2},
 614         {"ad5629-3", ID_AD5628_2}, /* similar enough to ad5629-2 */
 615         {"ad5669-1", ID_AD5668_1},
 616         {"ad5669-2", ID_AD5668_2},
 617         {"ad5669-3", ID_AD5668_2}, /* similar enough to ad5669-2 */
 618         {}
 619 };
 620 MODULE_DEVICE_TABLE(i2c, ad5064_i2c_ids);
 621
 622 static struct i2c_driver ad5064_i2c_driver = {
 623         .driver = {
 624                    .name = "ad5064",
 625                    .owner = THIS_MODULE,
 626         },
 627         .probe = ad5064_i2c_probe,
 628         .remove = ad5064_i2c_remove,
 629         .id_table = ad5064_i2c_ids,
 630 };
 631
 632 static int __init ad5064_i2c_register_driver(void)
 633 {
 634         return i2c_add_driver(&ad5064_i2c_driver);
 635 }
 636
 637 static void __exit ad5064_i2c_unregister_driver(void)
 638 {
 639         i2c_del_driver(&ad5064_i2c_driver);
 640 }
 641
 642 #else
 643
 644 static inline int ad5064_i2c_register_driver(void) { return 0; }
 645 static inline void ad5064_i2c_unregister_driver(void) { }
 646
 647 #endif
 648
 649 static int __init ad5064_init(void)
 650 {
 651         int ret;
 652
 653         ret = ad5064_spi_register_driver();
 654         if (ret)
 655                 return ret;
 656
 657         ret = ad5064_i2c_register_driver();
 658         if (ret) {
 659                 ad5064_spi_unregister_driver();
 660                 return ret;
 661         }
 662
 663         return 0;
 664 }
 665 module_init(ad5064_init);
 666
 667 static void __exit ad5064_exit(void)
 668 {
 669         ad5064_i2c_unregister_driver();
 670         ad5064_spi_unregister_driver();
 671 }
 672 module_exit(ad5064_exit);
 673
 674 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 675 MODULE_DESCRIPTION("Analog Devices AD5024 and similar multi-channel DACs");
 676 MODULE_LICENSE("GPL v2");