drivers/iio/dac/ad5449.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AD5415, AD5426, AD5429, AD5432, AD5439, AD5443, AD5449 Digital to Analog
   4  * Converter driver.
   5  *
   6  * Copyright 2012 Analog Devices Inc.
   7  *  Author: Lars-Peter Clausen <lars@metafoo.de>
   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/slab.h>
  16 #include <linux/sysfs.h>
  17 #include <linux/regulator/consumer.h>
  18 #include <asm/unaligned.h>
  19
  20 #include <linux/iio/iio.h>
  21 #include <linux/iio/sysfs.h>
  22
  23 #include <linux/platform_data/ad5449.h>
  24
  25 #define AD5449_MAX_CHANNELS             2
  26 #define AD5449_MAX_VREFS                2
  27
  28 #define AD5449_CMD_NOOP                 0x0
  29 #define AD5449_CMD_LOAD_AND_UPDATE(x)   (0x1 + (x) * 3)
  30 #define AD5449_CMD_READ(x)              (0x2 + (x) * 3)
  31 #define AD5449_CMD_LOAD(x)              (0x3 + (x) * 3)
  32 #define AD5449_CMD_CTRL                 13
  33
  34 #define AD5449_CTRL_SDO_OFFSET          10
  35 #define AD5449_CTRL_DAISY_CHAIN         BIT(9)
  36 #define AD5449_CTRL_HCLR_TO_MIDSCALE    BIT(8)
  37 #define AD5449_CTRL_SAMPLE_RISING       BIT(7)
  38
  39 /**
  40  * struct ad5449_chip_info - chip specific information
  41  * @channels:           Channel specification
  42  * @num_channels:       Number of channels
  43  * @has_ctrl:           Chip has a control register
  44  */
  45 struct ad5449_chip_info {
  46         const struct iio_chan_spec *channels;
  47         unsigned int num_channels;
  48         bool has_ctrl;
  49 };
  50
  51 /**
  52  * struct ad5449 - driver instance specific data
  53  * @spi:                the SPI device for this driver instance
  54  * @chip_info:          chip model specific constants, available modes etc
  55  * @vref_reg:           vref supply regulators
  56  * @has_sdo:            whether the SDO line is connected
  57  * @dac_cache:          Cache for the DAC values
  58  * @data:               spi transfer buffers
  59  */
  60 struct ad5449 {
  61         struct spi_device               *spi;
  62         const struct ad5449_chip_info   *chip_info;
  63         struct regulator_bulk_data      vref_reg[AD5449_MAX_VREFS];
  64
  65         bool has_sdo;
  66         uint16_t dac_cache[AD5449_MAX_CHANNELS];
  67
  68         /*
  69          * DMA (thus cache coherency maintenance) requires the
  70          * transfer buffers to live in their own cache lines.
  71          */
  72         __be16 data[2] ____cacheline_aligned;
  73 };
  74
  75 enum ad5449_type {
  76         ID_AD5426,
  77         ID_AD5429,
  78         ID_AD5432,
  79         ID_AD5439,
  80         ID_AD5443,
  81         ID_AD5449,
  82 };
  83
  84 static int ad5449_write(struct iio_dev *indio_dev, unsigned int addr,
  85         unsigned int val)
  86 {
  87         struct ad5449 *st = iio_priv(indio_dev);
  88         int ret;
  89
  90         mutex_lock(&indio_dev->mlock);
  91         st->data[0] = cpu_to_be16((addr << 12) | val);
  92         ret = spi_write(st->spi, st->data, 2);
  93         mutex_unlock(&indio_dev->mlock);
  94
  95         return ret;
  96 }
  97
  98 static int ad5449_read(struct iio_dev *indio_dev, unsigned int addr,
  99         unsigned int *val)
 100 {
 101         struct ad5449 *st = iio_priv(indio_dev);
 102         int ret;
 103         struct spi_transfer t[] = {
 104                 {
 105                         .tx_buf = &st->data[0],
 106                         .len = 2,
 107                         .cs_change = 1,
 108                 }, {
 109                         .tx_buf = &st->data[1],
 110                         .rx_buf = &st->data[1],
 111                         .len = 2,
 112                 },
 113         };
 114
 115         mutex_lock(&indio_dev->mlock);
 116         st->data[0] = cpu_to_be16(addr << 12);
 117         st->data[1] = cpu_to_be16(AD5449_CMD_NOOP);
 118
 119         ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
 120         if (ret < 0)
 121                 goto out_unlock;
 122
 123         *val = be16_to_cpu(st->data[1]);
 124
 125 out_unlock:
 126         mutex_unlock(&indio_dev->mlock);
 127         return ret;
 128 }
 129
 130 static int ad5449_read_raw(struct iio_dev *indio_dev,
 131         struct iio_chan_spec const *chan, int *val, int *val2, long info)
 132 {
 133         struct ad5449 *st = iio_priv(indio_dev);
 134         struct regulator_bulk_data *reg;
 135         int scale_uv;
 136         int ret;
 137
 138         switch (info) {
 139         case IIO_CHAN_INFO_RAW:
 140                 if (st->has_sdo) {
 141                         ret = ad5449_read(indio_dev,
 142                                 AD5449_CMD_READ(chan->address), val);
 143                         if (ret)
 144                                 return ret;
 145                         *val &= 0xfff;
 146                 } else {
 147                         *val = st->dac_cache[chan->address];
 148                 }
 149
 150                 return IIO_VAL_INT;
 151         case IIO_CHAN_INFO_SCALE:
 152                 reg = &st->vref_reg[chan->channel];
 153                 scale_uv = regulator_get_voltage(reg->consumer);
 154                 if (scale_uv < 0)
 155                         return scale_uv;
 156
 157                 *val = scale_uv / 1000;
 158                 *val2 = chan->scan_type.realbits;
 159
 160                 return IIO_VAL_FRACTIONAL_LOG2;
 161         default:
 162                 break;
 163         }
 164
 165         return -EINVAL;
 166 }
 167
 168 static int ad5449_write_raw(struct iio_dev *indio_dev,
 169         struct iio_chan_spec const *chan, int val, int val2, long info)
 170 {
 171         struct ad5449 *st = iio_priv(indio_dev);
 172         int ret;
 173
 174         switch (info) {
 175         case IIO_CHAN_INFO_RAW:
 176                 if (val < 0 || val >= (1 << chan->scan_type.realbits))
 177                         return -EINVAL;
 178
 179                 ret = ad5449_write(indio_dev,
 180                         AD5449_CMD_LOAD_AND_UPDATE(chan->address),
 181                         val << chan->scan_type.shift);
 182                 if (ret == 0)
 183                         st->dac_cache[chan->address] = val;
 184                 break;
 185         default:
 186                 ret = -EINVAL;
 187         }
 188
 189         return ret;
 190 }
 191
 192 static const struct iio_info ad5449_info = {
 193         .read_raw = ad5449_read_raw,
 194         .write_raw = ad5449_write_raw,
 195 };
 196
 197 #define AD5449_CHANNEL(chan, bits) {                            \
 198         .type = IIO_VOLTAGE,                                    \
 199         .indexed = 1,                                           \
 200         .output = 1,                                            \
 201         .channel = (chan),                                      \
 202         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
 203                 BIT(IIO_CHAN_INFO_SCALE),                       \
 204         .address = (chan),                                      \
 205         .scan_type = {                                          \
 206                 .sign = 'u',                                    \
 207                 .realbits = (bits),                             \
 208                 .storagebits = 16,                              \
 209                 .shift = 12 - (bits),                           \
 210         },                                                      \
 211 }
 212
 213 #define DECLARE_AD5449_CHANNELS(name, bits) \
 214 const struct iio_chan_spec name[] = { \
 215         AD5449_CHANNEL(0, bits), \
 216         AD5449_CHANNEL(1, bits), \
 217 }
 218
 219 static DECLARE_AD5449_CHANNELS(ad5429_channels, 8);
 220 static DECLARE_AD5449_CHANNELS(ad5439_channels, 10);
 221 static DECLARE_AD5449_CHANNELS(ad5449_channels, 12);
 222
 223 static const struct ad5449_chip_info ad5449_chip_info[] = {
 224         [ID_AD5426] = {
 225                 .channels = ad5429_channels,
 226                 .num_channels = 1,
 227                 .has_ctrl = false,
 228         },
 229         [ID_AD5429] = {
 230                 .channels = ad5429_channels,
 231                 .num_channels = 2,
 232                 .has_ctrl = true,
 233         },
 234         [ID_AD5432] = {
 235                 .channels = ad5439_channels,
 236                 .num_channels = 1,
 237                 .has_ctrl = false,
 238         },
 239         [ID_AD5439] = {
 240                 .channels = ad5439_channels,
 241                 .num_channels = 2,
 242                 .has_ctrl = true,
 243         },
 244         [ID_AD5443] = {
 245                 .channels = ad5449_channels,
 246                 .num_channels = 1,
 247                 .has_ctrl = false,
 248         },
 249         [ID_AD5449] = {
 250                 .channels = ad5449_channels,
 251                 .num_channels = 2,
 252                 .has_ctrl = true,
 253         },
 254 };
 255
 256 static const char *ad5449_vref_name(struct ad5449 *st, int n)
 257 {
 258         if (st->chip_info->num_channels == 1)
 259                 return "VREF";
 260
 261         if (n == 0)
 262                 return "VREFA";
 263         else
 264                 return "VREFB";
 265 }
 266
 267 static int ad5449_spi_probe(struct spi_device *spi)
 268 {
 269         struct ad5449_platform_data *pdata = spi->dev.platform_data;
 270         const struct spi_device_id *id = spi_get_device_id(spi);
 271         struct iio_dev *indio_dev;
 272         struct ad5449 *st;
 273         unsigned int i;
 274         int ret;
 275
 276         indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 277         if (indio_dev == NULL)
 278                 return -ENOMEM;
 279
 280         st = iio_priv(indio_dev);
 281         spi_set_drvdata(spi, indio_dev);
 282
 283         st->chip_info = &ad5449_chip_info[id->driver_data];
 284         st->spi = spi;
 285
 286         for (i = 0; i < st->chip_info->num_channels; ++i)
 287                 st->vref_reg[i].supply = ad5449_vref_name(st, i);
 288
 289         ret = devm_regulator_bulk_get(&spi->dev, st->chip_info->num_channels,
 290                                 st->vref_reg);
 291         if (ret)
 292                 return ret;
 293
 294         ret = regulator_bulk_enable(st->chip_info->num_channels, st->vref_reg);
 295         if (ret)
 296                 return ret;
 297
 298         indio_dev->dev.parent = &spi->dev;
 299         indio_dev->name = id->name;
 300         indio_dev->info = &ad5449_info;
 301         indio_dev->modes = INDIO_DIRECT_MODE;
 302         indio_dev->channels = st->chip_info->channels;
 303         indio_dev->num_channels = st->chip_info->num_channels;
 304
 305         if (st->chip_info->has_ctrl) {
 306                 unsigned int ctrl = 0x00;
 307                 if (pdata) {
 308                         if (pdata->hardware_clear_to_midscale)
 309                                 ctrl |= AD5449_CTRL_HCLR_TO_MIDSCALE;
 310                         ctrl |= pdata->sdo_mode << AD5449_CTRL_SDO_OFFSET;
 311                         st->has_sdo = pdata->sdo_mode != AD5449_SDO_DISABLED;
 312                 } else {
 313                         st->has_sdo = true;
 314                 }
 315                 ad5449_write(indio_dev, AD5449_CMD_CTRL, ctrl);
 316         }
 317
 318         ret = iio_device_register(indio_dev);
 319         if (ret)
 320                 goto error_disable_reg;
 321
 322         return 0;
 323
 324 error_disable_reg:
 325         regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
 326
 327         return ret;
 328 }
 329
 330 static int ad5449_spi_remove(struct spi_device *spi)
 331 {
 332         struct iio_dev *indio_dev = spi_get_drvdata(spi);
 333         struct ad5449 *st = iio_priv(indio_dev);
 334
 335         iio_device_unregister(indio_dev);
 336
 337         regulator_bulk_disable(st->chip_info->num_channels, st->vref_reg);
 338
 339         return 0;
 340 }
 341
 342 static const struct spi_device_id ad5449_spi_ids[] = {
 343         { "ad5415", ID_AD5449 },
 344         { "ad5426", ID_AD5426 },
 345         { "ad5429", ID_AD5429 },
 346         { "ad5432", ID_AD5432 },
 347         { "ad5439", ID_AD5439 },
 348         { "ad5443", ID_AD5443 },
 349         { "ad5449", ID_AD5449 },
 350         {}
 351 };
 352 MODULE_DEVICE_TABLE(spi, ad5449_spi_ids);
 353
 354 static struct spi_driver ad5449_spi_driver = {
 355         .driver = {
 356                 .name = "ad5449",
 357         },
 358         .probe = ad5449_spi_probe,
 359         .remove = ad5449_spi_remove,
 360         .id_table = ad5449_spi_ids,
 361 };
 362 module_spi_driver(ad5449_spi_driver);
 363
 364 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 365 MODULE_DESCRIPTION("Analog Devices AD5449 and similar DACs");
 366 MODULE_LICENSE("GPL v2");