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  * https://www.ti.com/lit/ds/symlink/dac121c081.pdf
  17  */
  18
  19 #include <linux/iio/iio.h>
  20 #include <linux/i2c.h>
  21 #include <linux/module.h>
  22 #include <linux/mod_devicetable.h>
  23 #include <linux/property.h>
  24 #include <linux/regulator/consumer.h>
  25
  26 enum chip_id {
  27         single_8bit, single_10bit, single_12bit,
  28         quad_8bit, quad_10bit, quad_12bit
  29 };
  30
  31 struct dac5571_spec {
  32         u8 num_channels;
  33         u8 resolution;
  34 };
  35
  36 static const struct dac5571_spec dac5571_spec[] = {
  37         [single_8bit]  = {.num_channels = 1, .resolution =  8},
  38         [single_10bit] = {.num_channels = 1, .resolution = 10},
  39         [single_12bit] = {.num_channels = 1, .resolution = 12},
  40         [quad_8bit]    = {.num_channels = 4, .resolution =  8},
  41         [quad_10bit]   = {.num_channels = 4, .resolution = 10},
  42         [quad_12bit]   = {.num_channels = 4, .resolution = 12},
  43 };
  44
  45 struct dac5571_data {
  46         struct i2c_client *client;
  47         int id;
  48         struct mutex lock;
  49         struct regulator *vref;
  50         u16 val[4];
  51         bool powerdown[4];
  52         u8 powerdown_mode[4];
  53         struct dac5571_spec const *spec;
  54         int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
  55         int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
  56         u8 buf[3] __aligned(IIO_DMA_MINALIGN);
  57 };
  58
  59 #define DAC5571_POWERDOWN(mode)         ((mode) + 1)
  60 #define DAC5571_POWERDOWN_FLAG          BIT(0)
  61 #define DAC5571_CHANNEL_SELECT          1
  62 #define DAC5571_LOADMODE_DIRECT         BIT(4)
  63 #define DAC5571_SINGLE_PWRDWN_BITS      4
  64 #define DAC5571_QUAD_PWRDWN_BITS        6
  65
  66 static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
  67 {
  68         unsigned int shift;
  69
  70         shift = 12 - data->spec->resolution;
  71         data->buf[1] = val << shift;
  72         data->buf[0] = val >> (8 - shift);
  73
  74         if (i2c_master_send(data->client, data->buf, 2) != 2)
  75                 return -EIO;
  76
  77         return 0;
  78 }
  79
  80 static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
  81 {
  82         unsigned int shift;
  83
  84         shift = 16 - data->spec->resolution;
  85         data->buf[2] = val << shift;
  86         data->buf[1] = (val >> (8 - shift));
  87         data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
  88                        DAC5571_LOADMODE_DIRECT;
  89
  90         if (i2c_master_send(data->client, data->buf, 3) != 3)
  91                 return -EIO;
  92
  93         return 0;
  94 }
  95
  96 static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
  97 {
  98         data->buf[1] = 0;
  99         data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
 100
 101         if (i2c_master_send(data->client, data->buf, 2) != 2)
 102                 return -EIO;
 103
 104         return 0;
 105 }
 106
 107 static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
 108 {
 109         data->buf[2] = 0;
 110         data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
 111         data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
 112                        DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
 113
 114         if (i2c_master_send(data->client, data->buf, 3) != 3)
 115                 return -EIO;
 116
 117         return 0;
 118 }
 119
 120 static const char *const dac5571_powerdown_modes[] = {
 121         "1kohm_to_gnd", "100kohm_to_gnd", "three_state",
 122 };
 123
 124 static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
 125                                       const struct iio_chan_spec *chan)
 126 {
 127         struct dac5571_data *data = iio_priv(indio_dev);
 128
 129         return data->powerdown_mode[chan->channel];
 130 }
 131
 132 static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
 133                                       const struct iio_chan_spec *chan,
 134                                       unsigned int mode)
 135 {
 136         struct dac5571_data *data = iio_priv(indio_dev);
 137         int ret = 0;
 138
 139         if (data->powerdown_mode[chan->channel] == mode)
 140                 return 0;
 141
 142         mutex_lock(&data->lock);
 143         if (data->powerdown[chan->channel]) {
 144                 ret = data->dac5571_pwrdwn(data, chan->channel,
 145                                            DAC5571_POWERDOWN(mode));
 146                 if (ret)
 147                         goto out;
 148         }
 149         data->powerdown_mode[chan->channel] = mode;
 150
 151  out:
 152         mutex_unlock(&data->lock);
 153
 154         return ret;
 155 }
 156
 157 static const struct iio_enum dac5571_powerdown_mode = {
 158         .items = dac5571_powerdown_modes,
 159         .num_items = ARRAY_SIZE(dac5571_powerdown_modes),
 160         .get = dac5571_get_powerdown_mode,
 161         .set = dac5571_set_powerdown_mode,
 162 };
 163
 164 static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
 165                                       uintptr_t private,
 166                                       const struct iio_chan_spec *chan,
 167                                       char *buf)
 168 {
 169         struct dac5571_data *data = iio_priv(indio_dev);
 170
 171         return sysfs_emit(buf, "%d\n", data->powerdown[chan->channel]);
 172 }
 173
 174 static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
 175                                        uintptr_t private,
 176                                        const struct iio_chan_spec *chan,
 177                                        const char *buf, size_t len)
 178 {
 179         struct dac5571_data *data = iio_priv(indio_dev);
 180         bool powerdown;
 181         int ret;
 182
 183         ret = kstrtobool(buf, &powerdown);
 184         if (ret)
 185                 return ret;
 186
 187         if (data->powerdown[chan->channel] == powerdown)
 188                 return len;
 189
 190         mutex_lock(&data->lock);
 191         if (powerdown)
 192                 ret = data->dac5571_pwrdwn(data, chan->channel,
 193                             DAC5571_POWERDOWN(data->powerdown_mode[chan->channel]));
 194         else
 195                 ret = data->dac5571_cmd(data, chan->channel,
 196                                 data->val[chan->channel]);
 197         if (ret)
 198                 goto out;
 199
 200         data->powerdown[chan->channel] = powerdown;
 201
 202  out:
 203         mutex_unlock(&data->lock);
 204
 205         return ret ? ret : len;
 206 }
 207
 208
 209 static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
 210         {
 211                 .name      = "powerdown",
 212                 .read      = dac5571_read_powerdown,
 213                 .write     = dac5571_write_powerdown,
 214                 .shared    = IIO_SEPARATE,
 215         },
 216         IIO_ENUM("powerdown_mode", IIO_SEPARATE, &dac5571_powerdown_mode),
 217         IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
 218         {},
 219 };
 220
 221 #define dac5571_CHANNEL(chan, name) {                           \
 222         .type = IIO_VOLTAGE,                                    \
 223         .channel = (chan),                                      \
 224         .address = (chan),                                      \
 225         .indexed = true,                                        \
 226         .output = true,                                         \
 227         .datasheet_name = name,                                 \
 228         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 229         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
 230         .ext_info = dac5571_ext_info,                           \
 231 }
 232
 233 static const struct iio_chan_spec dac5571_channels[] = {
 234         dac5571_CHANNEL(0, "A"),
 235         dac5571_CHANNEL(1, "B"),
 236         dac5571_CHANNEL(2, "C"),
 237         dac5571_CHANNEL(3, "D"),
 238 };
 239
 240 static int dac5571_read_raw(struct iio_dev *indio_dev,
 241                             struct iio_chan_spec const *chan,
 242                             int *val, int *val2, long mask)
 243 {
 244         struct dac5571_data *data = iio_priv(indio_dev);
 245         int ret;
 246
 247         switch (mask) {
 248         case IIO_CHAN_INFO_RAW:
 249                 *val = data->val[chan->channel];
 250                 return IIO_VAL_INT;
 251
 252         case IIO_CHAN_INFO_SCALE:
 253                 ret = regulator_get_voltage(data->vref);
 254                 if (ret < 0)
 255                         return ret;
 256
 257                 *val = ret / 1000;
 258                 *val2 = data->spec->resolution;
 259                 return IIO_VAL_FRACTIONAL_LOG2;
 260
 261         default:
 262                 return -EINVAL;
 263         }
 264 }
 265
 266 static int dac5571_write_raw(struct iio_dev *indio_dev,
 267                              struct iio_chan_spec const *chan,
 268                              int val, int val2, long mask)
 269 {
 270         struct dac5571_data *data = iio_priv(indio_dev);
 271         int ret;
 272
 273         switch (mask) {
 274         case IIO_CHAN_INFO_RAW:
 275                 if (data->val[chan->channel] == val)
 276                         return 0;
 277
 278                 if (val >= (1 << data->spec->resolution) || val < 0)
 279                         return -EINVAL;
 280
 281                 if (data->powerdown[chan->channel])
 282                         return -EBUSY;
 283
 284                 mutex_lock(&data->lock);
 285                 ret = data->dac5571_cmd(data, chan->channel, val);
 286                 if (ret == 0)
 287                         data->val[chan->channel] = val;
 288                 mutex_unlock(&data->lock);
 289                 return ret;
 290
 291         default:
 292                 return -EINVAL;
 293         }
 294 }
 295
 296 static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
 297                                      struct iio_chan_spec const *chan,
 298                                      long mask)
 299 {
 300         return IIO_VAL_INT;
 301 }
 302
 303 static const struct iio_info dac5571_info = {
 304         .read_raw = dac5571_read_raw,
 305         .write_raw = dac5571_write_raw,
 306         .write_raw_get_fmt = dac5571_write_raw_get_fmt,
 307 };
 308
 309 static int dac5571_probe(struct i2c_client *client)
 310 {
 311         const struct i2c_device_id *id = i2c_client_get_device_id(client);
 312         struct device *dev = &client->dev;
 313         const struct dac5571_spec *spec;
 314         struct dac5571_data *data;
 315         struct iio_dev *indio_dev;
 316         int ret, i;
 317
 318         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 319         if (!indio_dev)
 320                 return -ENOMEM;
 321
 322         data = iio_priv(indio_dev);
 323         i2c_set_clientdata(client, indio_dev);
 324         data->client = client;
 325
 326         indio_dev->info = &dac5571_info;
 327         indio_dev->name = id->name;
 328         indio_dev->modes = INDIO_DIRECT_MODE;
 329         indio_dev->channels = dac5571_channels;
 330
 331         spec = i2c_get_match_data(client);
 332
 333         indio_dev->num_channels = spec->num_channels;
 334         data->spec = spec;
 335
 336         data->vref = devm_regulator_get(dev, "vref");
 337         if (IS_ERR(data->vref))
 338                 return PTR_ERR(data->vref);
 339
 340         ret = regulator_enable(data->vref);
 341         if (ret < 0)
 342                 return ret;
 343
 344         mutex_init(&data->lock);
 345
 346         switch (spec->num_channels) {
 347         case 1:
 348                 data->dac5571_cmd = dac5571_cmd_single;
 349                 data->dac5571_pwrdwn = dac5571_pwrdwn_single;
 350                 break;
 351         case 4:
 352                 data->dac5571_cmd = dac5571_cmd_quad;
 353                 data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
 354                 break;
 355         default:
 356                 ret = -EINVAL;
 357                 goto err;
 358         }
 359
 360         for (i = 0; i < spec->num_channels; i++) {
 361                 ret = data->dac5571_cmd(data, i, 0);
 362                 if (ret) {
 363                         dev_err(dev, "failed to initialize channel %d to 0\n", i);
 364                         goto err;
 365                 }
 366         }
 367
 368         ret = iio_device_register(indio_dev);
 369         if (ret)
 370                 goto err;
 371
 372         return 0;
 373
 374  err:
 375         regulator_disable(data->vref);
 376         return ret;
 377 }
 378
 379 static void dac5571_remove(struct i2c_client *i2c)
 380 {
 381         struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
 382         struct dac5571_data *data = iio_priv(indio_dev);
 383
 384         iio_device_unregister(indio_dev);
 385         regulator_disable(data->vref);
 386 }
 387
 388 static const struct of_device_id dac5571_of_id[] = {
 389         {.compatible = "ti,dac121c081", .data = &dac5571_spec[single_12bit] },
 390         {.compatible = "ti,dac5571", .data = &dac5571_spec[single_8bit] },
 391         {.compatible = "ti,dac6571", .data = &dac5571_spec[single_10bit] },
 392         {.compatible = "ti,dac7571", .data = &dac5571_spec[single_12bit] },
 393         {.compatible = "ti,dac5574", .data = &dac5571_spec[quad_8bit] },
 394         {.compatible = "ti,dac6574", .data = &dac5571_spec[quad_10bit] },
 395         {.compatible = "ti,dac7574", .data = &dac5571_spec[quad_12bit] },
 396         {.compatible = "ti,dac5573", .data = &dac5571_spec[quad_8bit] },
 397         {.compatible = "ti,dac6573", .data = &dac5571_spec[quad_10bit] },
 398         {.compatible = "ti,dac7573", .data = &dac5571_spec[quad_12bit] },
 399         {}
 400 };
 401 MODULE_DEVICE_TABLE(of, dac5571_of_id);
 402
 403 static const struct i2c_device_id dac5571_id[] = {
 404         {"dac121c081", (kernel_ulong_t)&dac5571_spec[single_12bit] },
 405         {"dac5571", (kernel_ulong_t)&dac5571_spec[single_8bit] },
 406         {"dac6571", (kernel_ulong_t)&dac5571_spec[single_10bit] },
 407         {"dac7571", (kernel_ulong_t)&dac5571_spec[single_12bit] },
 408         {"dac5574", (kernel_ulong_t)&dac5571_spec[quad_8bit] },
 409         {"dac6574", (kernel_ulong_t)&dac5571_spec[quad_10bit] },
 410         {"dac7574", (kernel_ulong_t)&dac5571_spec[quad_12bit] },
 411         {"dac5573", (kernel_ulong_t)&dac5571_spec[quad_8bit] },
 412         {"dac6573", (kernel_ulong_t)&dac5571_spec[quad_10bit] },
 413         {"dac7573", (kernel_ulong_t)&dac5571_spec[quad_12bit] },
 414         {}
 415 };
 416 MODULE_DEVICE_TABLE(i2c, dac5571_id);
 417
 418 static struct i2c_driver dac5571_driver = {
 419         .driver = {
 420                    .name = "ti-dac5571",
 421                    .of_match_table = dac5571_of_id,
 422         },
 423         .probe = dac5571_probe,
 424         .remove   = dac5571_remove,
 425         .id_table = dac5571_id,
 426 };
 427 module_i2c_driver(dac5571_driver);
 428
 429 MODULE_AUTHOR("Sean Nyekjaer <sean@geanix.dk>");
 430 MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
 431 MODULE_LICENSE("GPL v2");