drivers/iio/dac/ad5446.c

   1 /*
   2  * AD5446 SPI DAC driver
   3  *
   4  * Copyright 2010 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/device.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/sysfs.h>
  15 #include <linux/list.h>
  16 #include <linux/spi/spi.h>
  17 #include <linux/i2c.h>
  18 #include <linux/regulator/consumer.h>
  19 #include <linux/err.h>
  20 #include <linux/module.h>
  21
  22 #include <linux/iio/iio.h>
  23 #include <linux/iio/sysfs.h>
  24
  25 #define MODE_PWRDWN_1k          0x1
  26 #define MODE_PWRDWN_100k        0x2
  27 #define MODE_PWRDWN_TRISTATE    0x3
  28
  29 /**
  30  * struct ad5446_state - driver instance specific data
  31  * @spi:                spi_device
  32  * @chip_info:          chip model specific constants, available modes etc
  33  * @reg:                supply regulator
  34  * @vref_mv:            actual reference voltage used
  35  */
  36
  37 struct ad5446_state {
  38         struct device           *dev;
  39         const struct ad5446_chip_info   *chip_info;
  40         struct regulator                *reg;
  41         unsigned short                  vref_mv;
  42         unsigned                        cached_val;
  43         unsigned                        pwr_down_mode;
  44         unsigned                        pwr_down;
  45 };
  46
  47 /**
  48  * struct ad5446_chip_info - chip specific information
  49  * @channel:            channel spec for the DAC
  50  * @int_vref_mv:        AD5620/40/60: the internal reference voltage
  51  * @write:              chip specific helper function to write to the register
  52  */
  53
  54 struct ad5446_chip_info {
  55         struct iio_chan_spec    channel;
  56         u16                     int_vref_mv;
  57         int                     (*write)(struct ad5446_state *st, unsigned val);
  58 };
  59
  60 static const char * const ad5446_powerdown_modes[] = {
  61         "1kohm_to_gnd", "100kohm_to_gnd", "three_state"
  62 };
  63
  64 static int ad5446_set_powerdown_mode(struct iio_dev *indio_dev,
  65         const struct iio_chan_spec *chan, unsigned int mode)
  66 {
  67         struct ad5446_state *st = iio_priv(indio_dev);
  68
  69         st->pwr_down_mode = mode + 1;
  70
  71         return 0;
  72 }
  73
  74 static int ad5446_get_powerdown_mode(struct iio_dev *indio_dev,
  75         const struct iio_chan_spec *chan)
  76 {
  77         struct ad5446_state *st = iio_priv(indio_dev);
  78
  79         return st->pwr_down_mode - 1;
  80 }
  81
  82 static const struct iio_enum ad5446_powerdown_mode_enum = {
  83         .items = ad5446_powerdown_modes,
  84         .num_items = ARRAY_SIZE(ad5446_powerdown_modes),
  85         .get = ad5446_get_powerdown_mode,
  86         .set = ad5446_set_powerdown_mode,
  87 };
  88
  89 static ssize_t ad5446_read_dac_powerdown(struct iio_dev *indio_dev,
  90                                            uintptr_t private,
  91                                            const struct iio_chan_spec *chan,
  92                                            char *buf)
  93 {
  94         struct ad5446_state *st = iio_priv(indio_dev);
  95
  96         return sprintf(buf, "%d\n", st->pwr_down);
  97 }
  98
  99 static ssize_t ad5446_write_dac_powerdown(struct iio_dev *indio_dev,
 100                                             uintptr_t private,
 101                                             const struct iio_chan_spec *chan,
 102                                             const char *buf, size_t len)
 103 {
 104         struct ad5446_state *st = iio_priv(indio_dev);
 105         unsigned int shift;
 106         unsigned int val;
 107         bool powerdown;
 108         int ret;
 109
 110         ret = strtobool(buf, &powerdown);
 111         if (ret)
 112                 return ret;
 113
 114         mutex_lock(&indio_dev->mlock);
 115         st->pwr_down = powerdown;
 116
 117         if (st->pwr_down) {
 118                 shift = chan->scan_type.realbits + chan->scan_type.shift;
 119                 val = st->pwr_down_mode << shift;
 120         } else {
 121                 val = st->cached_val;
 122         }
 123
 124         ret = st->chip_info->write(st, val);
 125         mutex_unlock(&indio_dev->mlock);
 126
 127         return ret ? ret : len;
 128 }
 129
 130 static const struct iio_chan_spec_ext_info ad5446_ext_info_powerdown[] = {
 131         {
 132                 .name = "powerdown",
 133                 .read = ad5446_read_dac_powerdown,
 134                 .write = ad5446_write_dac_powerdown,
 135                 .shared = IIO_SEPARATE,
 136         },
 137         IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5446_powerdown_mode_enum),
 138         IIO_ENUM_AVAILABLE("powerdown_mode", &ad5446_powerdown_mode_enum),
 139         { },
 140 };
 141
 142 #define _AD5446_CHANNEL(bits, storage, _shift, ext) { \
 143         .type = IIO_VOLTAGE, \
 144         .indexed = 1, \
 145         .output = 1, \
 146         .channel = 0, \
 147         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 148         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
 149         .scan_type = { \
 150                 .sign = 'u', \
 151                 .realbits = (bits), \
 152                 .storagebits = (storage), \
 153                 .shift = (_shift), \
 154                 }, \
 155         .ext_info = (ext), \
 156 }
 157
 158 #define AD5446_CHANNEL(bits, storage, shift) \
 159         _AD5446_CHANNEL(bits, storage, shift, NULL)
 160
 161 #define AD5446_CHANNEL_POWERDOWN(bits, storage, shift) \
 162         _AD5446_CHANNEL(bits, storage, shift, ad5446_ext_info_powerdown)
 163
 164 static int ad5446_read_raw(struct iio_dev *indio_dev,
 165                            struct iio_chan_spec const *chan,
 166                            int *val,
 167                            int *val2,
 168                            long m)
 169 {
 170         struct ad5446_state *st = iio_priv(indio_dev);
 171
 172         switch (m) {
 173         case IIO_CHAN_INFO_RAW:
 174                 *val = st->cached_val;
 175                 return IIO_VAL_INT;
 176         case IIO_CHAN_INFO_SCALE:
 177                 *val = st->vref_mv;
 178                 *val2 = chan->scan_type.realbits;
 179                 return IIO_VAL_FRACTIONAL_LOG2;
 180         }
 181         return -EINVAL;
 182 }
 183
 184 static int ad5446_write_raw(struct iio_dev *indio_dev,
 185                                struct iio_chan_spec const *chan,
 186                                int val,
 187                                int val2,
 188                                long mask)
 189 {
 190         struct ad5446_state *st = iio_priv(indio_dev);
 191         int ret = 0;
 192
 193         switch (mask) {
 194         case IIO_CHAN_INFO_RAW:
 195                 if (val >= (1 << chan->scan_type.realbits) || val < 0)
 196                         return -EINVAL;
 197
 198                 val <<= chan->scan_type.shift;
 199                 mutex_lock(&indio_dev->mlock);
 200                 st->cached_val = val;
 201                 if (!st->pwr_down)
 202                         ret = st->chip_info->write(st, val);
 203                 mutex_unlock(&indio_dev->mlock);
 204                 break;
 205         default:
 206                 ret = -EINVAL;
 207         }
 208
 209         return ret;
 210 }
 211
 212 static const struct iio_info ad5446_info = {
 213         .read_raw = ad5446_read_raw,
 214         .write_raw = ad5446_write_raw,
 215         .driver_module = THIS_MODULE,
 216 };
 217
 218 static int ad5446_probe(struct device *dev, const char *name,
 219                         const struct ad5446_chip_info *chip_info)
 220 {
 221         struct ad5446_state *st;
 222         struct iio_dev *indio_dev;
 223         struct regulator *reg;
 224         int ret, voltage_uv = 0;
 225
 226         reg = devm_regulator_get(dev, "vcc");
 227         if (!IS_ERR(reg)) {
 228                 ret = regulator_enable(reg);
 229                 if (ret)
 230                         return ret;
 231
 232                 ret = regulator_get_voltage(reg);
 233                 if (ret < 0)
 234                         goto error_disable_reg;
 235
 236                 voltage_uv = ret;
 237         }
 238
 239         indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 240         if (indio_dev == NULL) {
 241                 ret = -ENOMEM;
 242                 goto error_disable_reg;
 243         }
 244         st = iio_priv(indio_dev);
 245         st->chip_info = chip_info;
 246
 247         dev_set_drvdata(dev, indio_dev);
 248         st->reg = reg;
 249         st->dev = dev;
 250
 251         /* Establish that the iio_dev is a child of the device */
 252         indio_dev->dev.parent = dev;
 253         indio_dev->name = name;
 254         indio_dev->info = &ad5446_info;
 255         indio_dev->modes = INDIO_DIRECT_MODE;
 256         indio_dev->channels = &st->chip_info->channel;
 257         indio_dev->num_channels = 1;
 258
 259         st->pwr_down_mode = MODE_PWRDWN_1k;
 260
 261         if (st->chip_info->int_vref_mv)
 262                 st->vref_mv = st->chip_info->int_vref_mv;
 263         else if (voltage_uv)
 264                 st->vref_mv = voltage_uv / 1000;
 265         else
 266                 dev_warn(dev, "reference voltage unspecified\n");
 267
 268         ret = iio_device_register(indio_dev);
 269         if (ret)
 270                 goto error_disable_reg;
 271
 272         return 0;
 273
 274 error_disable_reg:
 275         if (!IS_ERR(reg))
 276                 regulator_disable(reg);
 277         return ret;
 278 }
 279
 280 static int ad5446_remove(struct device *dev)
 281 {
 282         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 283         struct ad5446_state *st = iio_priv(indio_dev);
 284
 285         iio_device_unregister(indio_dev);
 286         if (!IS_ERR(st->reg))
 287                 regulator_disable(st->reg);
 288
 289         return 0;
 290 }
 291
 292 #if IS_ENABLED(CONFIG_SPI_MASTER)
 293
 294 static int ad5446_write(struct ad5446_state *st, unsigned val)
 295 {
 296         struct spi_device *spi = to_spi_device(st->dev);
 297         __be16 data = cpu_to_be16(val);
 298
 299         return spi_write(spi, &data, sizeof(data));
 300 }
 301
 302 static int ad5660_write(struct ad5446_state *st, unsigned val)
 303 {
 304         struct spi_device *spi = to_spi_device(st->dev);
 305         uint8_t data[3];
 306
 307         data[0] = (val >> 16) & 0xFF;
 308         data[1] = (val >> 8) & 0xFF;
 309         data[2] = val & 0xFF;
 310
 311         return spi_write(spi, data, sizeof(data));
 312 }
 313
 314 /**
 315  * ad5446_supported_spi_device_ids:
 316  * The AD5620/40/60 parts are available in different fixed internal reference
 317  * voltage options. The actual part numbers may look differently
 318  * (and a bit cryptic), however this style is used to make clear which
 319  * parts are supported here.
 320  */
 321 enum ad5446_supported_spi_device_ids {
 322         ID_AD5300,
 323         ID_AD5310,
 324         ID_AD5320,
 325         ID_AD5444,
 326         ID_AD5446,
 327         ID_AD5450,
 328         ID_AD5451,
 329         ID_AD5541A,
 330         ID_AD5512A,
 331         ID_AD5553,
 332         ID_AD5601,
 333         ID_AD5611,
 334         ID_AD5621,
 335         ID_AD5641,
 336         ID_AD5620_2500,
 337         ID_AD5620_1250,
 338         ID_AD5640_2500,
 339         ID_AD5640_1250,
 340         ID_AD5660_2500,
 341         ID_AD5660_1250,
 342         ID_AD5662,
 343 };
 344
 345 static const struct ad5446_chip_info ad5446_spi_chip_info[] = {
 346         [ID_AD5300] = {
 347                 .channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
 348                 .write = ad5446_write,
 349         },
 350         [ID_AD5310] = {
 351                 .channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
 352                 .write = ad5446_write,
 353         },
 354         [ID_AD5320] = {
 355                 .channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
 356                 .write = ad5446_write,
 357         },
 358         [ID_AD5444] = {
 359                 .channel = AD5446_CHANNEL(12, 16, 2),
 360                 .write = ad5446_write,
 361         },
 362         [ID_AD5446] = {
 363                 .channel = AD5446_CHANNEL(14, 16, 0),
 364                 .write = ad5446_write,
 365         },
 366         [ID_AD5450] = {
 367                 .channel = AD5446_CHANNEL(8, 16, 6),
 368                 .write = ad5446_write,
 369         },
 370         [ID_AD5451] = {
 371                 .channel = AD5446_CHANNEL(10, 16, 4),
 372                 .write = ad5446_write,
 373         },
 374         [ID_AD5541A] = {
 375                 .channel = AD5446_CHANNEL(16, 16, 0),
 376                 .write = ad5446_write,
 377         },
 378         [ID_AD5512A] = {
 379                 .channel = AD5446_CHANNEL(12, 16, 4),
 380                 .write = ad5446_write,
 381         },
 382         [ID_AD5553] = {
 383                 .channel = AD5446_CHANNEL(14, 16, 0),
 384                 .write = ad5446_write,
 385         },
 386         [ID_AD5601] = {
 387                 .channel = AD5446_CHANNEL_POWERDOWN(8, 16, 6),
 388                 .write = ad5446_write,
 389         },
 390         [ID_AD5611] = {
 391                 .channel = AD5446_CHANNEL_POWERDOWN(10, 16, 4),
 392                 .write = ad5446_write,
 393         },
 394         [ID_AD5621] = {
 395                 .channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
 396                 .write = ad5446_write,
 397         },
 398         [ID_AD5641] = {
 399                 .channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
 400                 .write = ad5446_write,
 401         },
 402         [ID_AD5620_2500] = {
 403                 .channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
 404                 .int_vref_mv = 2500,
 405                 .write = ad5446_write,
 406         },
 407         [ID_AD5620_1250] = {
 408                 .channel = AD5446_CHANNEL_POWERDOWN(12, 16, 2),
 409                 .int_vref_mv = 1250,
 410                 .write = ad5446_write,
 411         },
 412         [ID_AD5640_2500] = {
 413                 .channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
 414                 .int_vref_mv = 2500,
 415                 .write = ad5446_write,
 416         },
 417         [ID_AD5640_1250] = {
 418                 .channel = AD5446_CHANNEL_POWERDOWN(14, 16, 0),
 419                 .int_vref_mv = 1250,
 420                 .write = ad5446_write,
 421         },
 422         [ID_AD5660_2500] = {
 423                 .channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
 424                 .int_vref_mv = 2500,
 425                 .write = ad5660_write,
 426         },
 427         [ID_AD5660_1250] = {
 428                 .channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
 429                 .int_vref_mv = 1250,
 430                 .write = ad5660_write,
 431         },
 432         [ID_AD5662] = {
 433                 .channel = AD5446_CHANNEL_POWERDOWN(16, 16, 0),
 434                 .write = ad5660_write,
 435         },
 436 };
 437
 438 static const struct spi_device_id ad5446_spi_ids[] = {
 439         {"ad5300", ID_AD5300},
 440         {"ad5310", ID_AD5310},
 441         {"ad5320", ID_AD5320},
 442         {"ad5444", ID_AD5444},
 443         {"ad5446", ID_AD5446},
 444         {"ad5450", ID_AD5450},
 445         {"ad5451", ID_AD5451},
 446         {"ad5452", ID_AD5444}, /* ad5452 is compatible to the ad5444 */
 447         {"ad5453", ID_AD5446}, /* ad5453 is compatible to the ad5446 */
 448         {"ad5512a", ID_AD5512A},
 449         {"ad5541a", ID_AD5541A},
 450         {"ad5542a", ID_AD5541A}, /* ad5541a and ad5542a are compatible */
 451         {"ad5543", ID_AD5541A}, /* ad5541a and ad5543 are compatible */
 452         {"ad5553", ID_AD5553},
 453         {"ad5601", ID_AD5601},
 454         {"ad5611", ID_AD5611},
 455         {"ad5621", ID_AD5621},
 456         {"ad5641", ID_AD5641},
 457         {"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
 458         {"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
 459         {"ad5640-2500", ID_AD5640_2500},
 460         {"ad5640-1250", ID_AD5640_1250},
 461         {"ad5660-2500", ID_AD5660_2500},
 462         {"ad5660-1250", ID_AD5660_1250},
 463         {"ad5662", ID_AD5662},
 464         {}
 465 };
 466 MODULE_DEVICE_TABLE(spi, ad5446_spi_ids);
 467
 468 static int ad5446_spi_probe(struct spi_device *spi)
 469 {
 470         const struct spi_device_id *id = spi_get_device_id(spi);
 471
 472         return ad5446_probe(&spi->dev, id->name,
 473                 &ad5446_spi_chip_info[id->driver_data]);
 474 }
 475
 476 static int ad5446_spi_remove(struct spi_device *spi)
 477 {
 478         return ad5446_remove(&spi->dev);
 479 }
 480
 481 static struct spi_driver ad5446_spi_driver = {
 482         .driver = {
 483                 .name   = "ad5446",
 484                 .owner  = THIS_MODULE,
 485         },
 486         .probe          = ad5446_spi_probe,
 487         .remove         = ad5446_spi_remove,
 488         .id_table       = ad5446_spi_ids,
 489 };
 490
 491 static int __init ad5446_spi_register_driver(void)
 492 {
 493         return spi_register_driver(&ad5446_spi_driver);
 494 }
 495
 496 static void ad5446_spi_unregister_driver(void)
 497 {
 498         spi_unregister_driver(&ad5446_spi_driver);
 499 }
 500
 501 #else
 502
 503 static inline int ad5446_spi_register_driver(void) { return 0; }
 504 static inline void ad5446_spi_unregister_driver(void) { }
 505
 506 #endif
 507
 508 #if IS_ENABLED(CONFIG_I2C)
 509
 510 static int ad5622_write(struct ad5446_state *st, unsigned val)
 511 {
 512         struct i2c_client *client = to_i2c_client(st->dev);
 513         __be16 data = cpu_to_be16(val);
 514
 515         return i2c_master_send(client, (char *)&data, sizeof(data));
 516 }
 517
 518 /**
 519  * ad5446_supported_i2c_device_ids:
 520  * The AD5620/40/60 parts are available in different fixed internal reference
 521  * voltage options. The actual part numbers may look differently
 522  * (and a bit cryptic), however this style is used to make clear which
 523  * parts are supported here.
 524  */
 525 enum ad5446_supported_i2c_device_ids {
 526         ID_AD5602,
 527         ID_AD5612,
 528         ID_AD5622,
 529 };
 530
 531 static const struct ad5446_chip_info ad5446_i2c_chip_info[] = {
 532         [ID_AD5602] = {
 533                 .channel = AD5446_CHANNEL_POWERDOWN(8, 16, 4),
 534                 .write = ad5622_write,
 535         },
 536         [ID_AD5612] = {
 537                 .channel = AD5446_CHANNEL_POWERDOWN(10, 16, 2),
 538                 .write = ad5622_write,
 539         },
 540         [ID_AD5622] = {
 541                 .channel = AD5446_CHANNEL_POWERDOWN(12, 16, 0),
 542                 .write = ad5622_write,
 543         },
 544 };
 545
 546 static int ad5446_i2c_probe(struct i2c_client *i2c,
 547                             const struct i2c_device_id *id)
 548 {
 549         return ad5446_probe(&i2c->dev, id->name,
 550                 &ad5446_i2c_chip_info[id->driver_data]);
 551 }
 552
 553 static int ad5446_i2c_remove(struct i2c_client *i2c)
 554 {
 555         return ad5446_remove(&i2c->dev);
 556 }
 557
 558 static const struct i2c_device_id ad5446_i2c_ids[] = {
 559         {"ad5301", ID_AD5602},
 560         {"ad5311", ID_AD5612},
 561         {"ad5321", ID_AD5622},
 562         {"ad5602", ID_AD5602},
 563         {"ad5612", ID_AD5612},
 564         {"ad5622", ID_AD5622},
 565         {}
 566 };
 567 MODULE_DEVICE_TABLE(i2c, ad5446_i2c_ids);
 568
 569 static struct i2c_driver ad5446_i2c_driver = {
 570         .driver = {
 571                    .name = "ad5446",
 572                    .owner = THIS_MODULE,
 573         },
 574         .probe = ad5446_i2c_probe,
 575         .remove = ad5446_i2c_remove,
 576         .id_table = ad5446_i2c_ids,
 577 };
 578
 579 static int __init ad5446_i2c_register_driver(void)
 580 {
 581         return i2c_add_driver(&ad5446_i2c_driver);
 582 }
 583
 584 static void __exit ad5446_i2c_unregister_driver(void)
 585 {
 586         i2c_del_driver(&ad5446_i2c_driver);
 587 }
 588
 589 #else
 590
 591 static inline int ad5446_i2c_register_driver(void) { return 0; }
 592 static inline void ad5446_i2c_unregister_driver(void) { }
 593
 594 #endif
 595
 596 static int __init ad5446_init(void)
 597 {
 598         int ret;
 599
 600         ret = ad5446_spi_register_driver();
 601         if (ret)
 602                 return ret;
 603
 604         ret = ad5446_i2c_register_driver();
 605         if (ret) {
 606                 ad5446_spi_unregister_driver();
 607                 return ret;
 608         }
 609
 610         return 0;
 611 }
 612 module_init(ad5446_init);
 613
 614 static void __exit ad5446_exit(void)
 615 {
 616         ad5446_i2c_unregister_driver();
 617         ad5446_spi_unregister_driver();
 618 }
 619 module_exit(ad5446_exit);
 620
 621 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 622 MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
 623 MODULE_LICENSE("GPL v2");