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