drivers/iio/dac/ti-dac5571.c

   1 /*
   2  * ti-dac5571.c - Texas Instruments 8/10/12-bit 1/4-channel DAC driver
   3  *
   4  * Copyright (C) 2018 Prevas A/S
   5  *
   6  * http://www.ti.com/lit/ds/symlink/dac5571.pdf
   7  * http://www.ti.com/lit/ds/symlink/dac6571.pdf
   8  * http://www.ti.com/lit/ds/symlink/dac7571.pdf
   9  * http://www.ti.com/lit/ds/symlink/dac5574.pdf
  10  * http://www.ti.com/lit/ds/symlink/dac6574.pdf
  11  * http://www.ti.com/lit/ds/symlink/dac7574.pdf
  12  * http://www.ti.com/lit/ds/symlink/dac5573.pdf
  13  * http://www.ti.com/lit/ds/symlink/dac6573.pdf
  14  * http://www.ti.com/lit/ds/symlink/dac7573.pdf
  15  *
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License (version 2) as
  18  * published by the Free Software Foundation.
  19  */
  20
  21 #include <linux/iio/iio.h>
  22 #include <linux/i2c.h>
  23 #include <linux/module.h>
  24 #include <linux/of_device.h>
  25 #include <linux/of.h>
  26 #include <linux/regulator/consumer.h>
  27
  28 enum chip_id {
  29         single_8bit, single_10bit, single_12bit,
  30         quad_8bit, quad_10bit, quad_12bit
  31 };
  32
  33 struct dac5571_spec {
  34         u8 num_channels;
  35         u8 resolution;
  36 };
  37
  38 static const struct dac5571_spec dac5571_spec[] = {
  39         [single_8bit]  = {.num_channels = 1, .resolution =  8},
  40         [single_10bit] = {.num_channels = 1, .resolution = 10},
  41         [single_12bit] = {.num_channels = 1, .resolution = 12},
  42         [quad_8bit]    = {.num_channels = 4, .resolution =  8},
  43         [quad_10bit]   = {.num_channels = 4, .resolution = 10},
  44         [quad_12bit]   = {.num_channels = 4, .resolution = 12},
  45 };
  46
  47 struct dac5571_data {
  48         struct i2c_client *client;
  49         int id;
  50         struct mutex lock;
  51         struct regulator *vref;
  52         u16 val[4];
  53         bool powerdown;
  54         u8 powerdown_mode;
  55         struct dac5571_spec const *spec;
  56         int (*dac5571_cmd)(struct dac5571_data *data, int channel, u16 val);
  57         int (*dac5571_pwrdwn)(struct dac5571_data *data, int channel, u8 pwrdwn);
  58         u8 buf[3] ____cacheline_aligned;
  59 };
  60
  61 #define DAC5571_POWERDOWN(mode)         ((mode) + 1)
  62 #define DAC5571_POWERDOWN_FLAG          BIT(0)
  63 #define DAC5571_CHANNEL_SELECT          1
  64 #define DAC5571_LOADMODE_DIRECT         BIT(4)
  65 #define DAC5571_SINGLE_PWRDWN_BITS      4
  66 #define DAC5571_QUAD_PWRDWN_BITS        6
  67
  68 static int dac5571_cmd_single(struct dac5571_data *data, int channel, u16 val)
  69 {
  70         unsigned int shift;
  71
  72         shift = 12 - data->spec->resolution;
  73         data->buf[1] = val << shift;
  74         data->buf[0] = val >> (8 - shift);
  75
  76         if (i2c_master_send(data->client, data->buf, 2) != 2)
  77                 return -EIO;
  78
  79         return 0;
  80 }
  81
  82 static int dac5571_cmd_quad(struct dac5571_data *data, int channel, u16 val)
  83 {
  84         unsigned int shift;
  85
  86         shift = 16 - data->spec->resolution;
  87         data->buf[2] = val << shift;
  88         data->buf[1] = (val >> (8 - shift));
  89         data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
  90                        DAC5571_LOADMODE_DIRECT;
  91
  92         if (i2c_master_send(data->client, data->buf, 3) != 3)
  93                 return -EIO;
  94
  95         return 0;
  96 }
  97
  98 static int dac5571_pwrdwn_single(struct dac5571_data *data, int channel, u8 pwrdwn)
  99 {
 100         data->buf[1] = 0;
 101         data->buf[0] = pwrdwn << DAC5571_SINGLE_PWRDWN_BITS;
 102
 103         if (i2c_master_send(data->client, data->buf, 2) != 2)
 104                 return -EIO;
 105
 106         return 0;
 107 }
 108
 109 static int dac5571_pwrdwn_quad(struct dac5571_data *data, int channel, u8 pwrdwn)
 110 {
 111         data->buf[2] = 0;
 112         data->buf[1] = pwrdwn << DAC5571_QUAD_PWRDWN_BITS;
 113         data->buf[0] = (channel << DAC5571_CHANNEL_SELECT) |
 114                        DAC5571_LOADMODE_DIRECT | DAC5571_POWERDOWN_FLAG;
 115
 116         if (i2c_master_send(data->client, data->buf, 3) != 3)
 117                 return -EIO;
 118
 119         return 0;
 120 }
 121
 122 static const char *const dac5571_powerdown_modes[] = {
 123         "1kohm_to_gnd", "100kohm_to_gnd", "three_state",
 124 };
 125
 126 static int dac5571_get_powerdown_mode(struct iio_dev *indio_dev,
 127                                       const struct iio_chan_spec *chan)
 128 {
 129         struct dac5571_data *data = iio_priv(indio_dev);
 130
 131         return data->powerdown_mode;
 132 }
 133
 134 static int dac5571_set_powerdown_mode(struct iio_dev *indio_dev,
 135                                       const struct iio_chan_spec *chan,
 136                                       unsigned int mode)
 137 {
 138         struct dac5571_data *data = iio_priv(indio_dev);
 139         int ret = 0;
 140
 141         if (data->powerdown_mode == mode)
 142                 return 0;
 143
 144         mutex_lock(&data->lock);
 145         if (data->powerdown) {
 146                 ret = data->dac5571_pwrdwn(data, chan->channel,
 147                                            DAC5571_POWERDOWN(mode));
 148                 if (ret)
 149                         goto out;
 150         }
 151         data->powerdown_mode = mode;
 152
 153  out:
 154         mutex_unlock(&data->lock);
 155
 156         return ret;
 157 }
 158
 159 static const struct iio_enum dac5571_powerdown_mode = {
 160         .items = dac5571_powerdown_modes,
 161         .num_items = ARRAY_SIZE(dac5571_powerdown_modes),
 162         .get = dac5571_get_powerdown_mode,
 163         .set = dac5571_set_powerdown_mode,
 164 };
 165
 166 static ssize_t dac5571_read_powerdown(struct iio_dev *indio_dev,
 167                                       uintptr_t private,
 168                                       const struct iio_chan_spec *chan,
 169                                       char *buf)
 170 {
 171         struct dac5571_data *data = iio_priv(indio_dev);
 172
 173         return sprintf(buf, "%d\n", data->powerdown);
 174 }
 175
 176 static ssize_t dac5571_write_powerdown(struct iio_dev *indio_dev,
 177                                        uintptr_t private,
 178                                        const struct iio_chan_spec *chan,
 179                                        const char *buf, size_t len)
 180 {
 181         struct dac5571_data *data = iio_priv(indio_dev);
 182         bool powerdown;
 183         int ret;
 184
 185         ret = strtobool(buf, &powerdown);
 186         if (ret)
 187                 return ret;
 188
 189         if (data->powerdown == powerdown)
 190                 return len;
 191
 192         mutex_lock(&data->lock);
 193         if (powerdown)
 194                 ret = data->dac5571_pwrdwn(data, chan->channel,
 195                             DAC5571_POWERDOWN(data->powerdown_mode));
 196         else
 197                 ret = data->dac5571_cmd(data, chan->channel, data->val[0]);
 198         if (ret)
 199                 goto out;
 200
 201         data->powerdown = powerdown;
 202
 203  out:
 204         mutex_unlock(&data->lock);
 205
 206         return ret ? ret : len;
 207 }
 208
 209
 210 static const struct iio_chan_spec_ext_info dac5571_ext_info[] = {
 211         {
 212                 .name      = "powerdown",
 213                 .read      = dac5571_read_powerdown,
 214                 .write     = dac5571_write_powerdown,
 215                 .shared    = IIO_SHARED_BY_TYPE,
 216         },
 217         IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &dac5571_powerdown_mode),
 218         IIO_ENUM_AVAILABLE("powerdown_mode", &dac5571_powerdown_mode),
 219         {},
 220 };
 221
 222 #define dac5571_CHANNEL(chan, name) {                           \
 223         .type = IIO_VOLTAGE,                                    \
 224         .channel = (chan),                                      \
 225         .address = (chan),                                      \
 226         .indexed = true,                                        \
 227         .output = true,                                         \
 228         .datasheet_name = name,                                 \
 229         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
 230         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
 231         .ext_info = dac5571_ext_info,                           \
 232 }
 233
 234 static const struct iio_chan_spec dac5571_channels[] = {
 235         dac5571_CHANNEL(0, "A"),
 236         dac5571_CHANNEL(1, "B"),
 237         dac5571_CHANNEL(2, "C"),
 238         dac5571_CHANNEL(3, "D"),
 239 };
 240
 241 static int dac5571_read_raw(struct iio_dev *indio_dev,
 242                             struct iio_chan_spec const *chan,
 243                             int *val, int *val2, long mask)
 244 {
 245         struct dac5571_data *data = iio_priv(indio_dev);
 246         int ret;
 247
 248         switch (mask) {
 249         case IIO_CHAN_INFO_RAW:
 250                 *val = data->val[chan->channel];
 251                 return IIO_VAL_INT;
 252
 253         case IIO_CHAN_INFO_SCALE:
 254                 ret = regulator_get_voltage(data->vref);
 255                 if (ret < 0)
 256                         return ret;
 257
 258                 *val = ret / 1000;
 259                 *val2 = data->spec->resolution;
 260                 return IIO_VAL_FRACTIONAL_LOG2;
 261
 262         default:
 263                 return -EINVAL;
 264         }
 265 }
 266
 267 static int dac5571_write_raw(struct iio_dev *indio_dev,
 268                              struct iio_chan_spec const *chan,
 269                              int val, int val2, long mask)
 270 {
 271         struct dac5571_data *data = iio_priv(indio_dev);
 272         int ret;
 273
 274         switch (mask) {
 275         case IIO_CHAN_INFO_RAW:
 276                 if (data->val[chan->channel] == val)
 277                         return 0;
 278
 279                 if (val >= (1 << data->spec->resolution) || val < 0)
 280                         return -EINVAL;
 281
 282                 if (data->powerdown)
 283                         return -EBUSY;
 284
 285                 mutex_lock(&data->lock);
 286                 ret = data->dac5571_cmd(data, chan->channel, val);
 287                 if (ret == 0)
 288                         data->val[chan->channel] = val;
 289                 mutex_unlock(&data->lock);
 290                 return ret;
 291
 292         default:
 293                 return -EINVAL;
 294         }
 295 }
 296
 297 static int dac5571_write_raw_get_fmt(struct iio_dev *indio_dev,
 298                                      struct iio_chan_spec const *chan,
 299                                      long mask)
 300 {
 301         return IIO_VAL_INT;
 302 }
 303
 304 static const struct iio_info dac5571_info = {
 305         .read_raw = dac5571_read_raw,
 306         .write_raw = dac5571_write_raw,
 307         .write_raw_get_fmt = dac5571_write_raw_get_fmt,
 308 };
 309
 310 static int dac5571_probe(struct i2c_client *client,
 311                          const struct i2c_device_id *id)
 312 {
 313         struct device *dev = &client->dev;
 314         const struct dac5571_spec *spec;
 315         struct dac5571_data *data;
 316         struct iio_dev *indio_dev;
 317         int ret, i;
 318
 319         indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 320         if (!indio_dev)
 321                 return -ENOMEM;
 322
 323         data = iio_priv(indio_dev);
 324         i2c_set_clientdata(client, indio_dev);
 325         data->client = client;
 326
 327         indio_dev->dev.parent = dev;
 328         indio_dev->dev.of_node = client->dev.of_node;
 329         indio_dev->info = &dac5571_info;
 330         indio_dev->name = id->name;
 331         indio_dev->modes = INDIO_DIRECT_MODE;
 332         indio_dev->channels = dac5571_channels;
 333
 334         spec = &dac5571_spec[id->driver_data];
 335         indio_dev->num_channels = spec->num_channels;
 336         data->spec = spec;
 337
 338         data->vref = devm_regulator_get(dev, "vref");
 339         if (IS_ERR(data->vref))
 340                 return PTR_ERR(data->vref);
 341
 342         ret = regulator_enable(data->vref);
 343         if (ret < 0)
 344                 return ret;
 345
 346         mutex_init(&data->lock);
 347
 348         switch (spec->num_channels) {
 349         case 1:
 350                 data->dac5571_cmd = dac5571_cmd_single;
 351                 data->dac5571_pwrdwn = dac5571_pwrdwn_single;
 352                 break;
 353         case 4:
 354                 data->dac5571_cmd = dac5571_cmd_quad;
 355                 data->dac5571_pwrdwn = dac5571_pwrdwn_quad;
 356                 break;
 357         default:
 358                 goto err;
 359         }
 360
 361         for (i = 0; i < spec->num_channels; i++) {
 362                 ret = data->dac5571_cmd(data, i, 0);
 363                 if (ret) {
 364                         dev_err(dev, "failed to initialize channel %d to 0\n", i);
 365                         goto err;
 366                 }
 367         }
 368
 369         ret = iio_device_register(indio_dev);
 370         if (ret)
 371                 goto err;
 372
 373         return 0;
 374
 375  err:
 376         regulator_disable(data->vref);
 377         return ret;
 378 }
 379
 380 static int dac5571_remove(struct i2c_client *i2c)
 381 {
 382         struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
 383         struct dac5571_data *data = iio_priv(indio_dev);
 384
 385         iio_device_unregister(indio_dev);
 386         regulator_disable(data->vref);
 387
 388         return 0;
 389 }
 390
 391 #ifdef CONFIG_OF
 392 static const struct of_device_id dac5571_of_id[] = {
 393         {.compatible = "ti,dac5571"},
 394         {.compatible = "ti,dac6571"},
 395         {.compatible = "ti,dac7571"},
 396         {.compatible = "ti,dac5574"},
 397         {.compatible = "ti,dac6574"},
 398         {.compatible = "ti,dac7574"},
 399         {.compatible = "ti,dac5573"},
 400         {.compatible = "ti,dac6573"},
 401         {.compatible = "ti,dac7573"},
 402         {}
 403 };
 404 MODULE_DEVICE_TABLE(of, dac5571_of_id);
 405 #endif
 406
 407 static const struct i2c_device_id dac5571_id[] = {
 408         {"dac5571", single_8bit},
 409         {"dac6571", single_10bit},
 410         {"dac7571", single_12bit},
 411         {"dac5574", quad_8bit},
 412         {"dac6574", quad_10bit},
 413         {"dac7574", quad_12bit},
 414         {"dac5573", quad_8bit},
 415         {"dac6573", quad_10bit},
 416         {"dac7573", quad_12bit},
 417         {}
 418 };
 419 MODULE_DEVICE_TABLE(i2c, dac5571_id);
 420
 421 static struct i2c_driver dac5571_driver = {
 422         .driver = {
 423                    .name = "ti-dac5571",
 424                    .of_match_table = of_match_ptr(dac5571_of_id),
 425         },
 426         .probe    = dac5571_probe,
 427         .remove   = dac5571_remove,
 428         .id_table = dac5571_id,
 429 };
 430 module_i2c_driver(dac5571_driver);
 431
 432 MODULE_AUTHOR("Sean Nyekjaer <sean.nyekjaer@prevas.dk>");
 433 MODULE_DESCRIPTION("Texas Instruments 8/10/12-bit 1/4-channel DAC driver");
 434 MODULE_LICENSE("GPL v2");