drivers/iio/accel/stk8ba50.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Sensortek STK8BA50 3-Axis Accelerometer
   4  *
   5  * Copyright (c) 2015, Intel Corporation.
   6  *
   7  * STK8BA50 7-bit I2C address: 0x18.
   8  */
   9
  10 #include <linux/acpi.h>
  11 #include <linux/i2c.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/iio/buffer.h>
  16 #include <linux/iio/iio.h>
  17 #include <linux/iio/sysfs.h>
  18 #include <linux/iio/trigger.h>
  19 #include <linux/iio/triggered_buffer.h>
  20 #include <linux/iio/trigger_consumer.h>
  21
  22 #define STK8BA50_REG_XOUT                       0x02
  23 #define STK8BA50_REG_YOUT                       0x04
  24 #define STK8BA50_REG_ZOUT                       0x06
  25 #define STK8BA50_REG_RANGE                      0x0F
  26 #define STK8BA50_REG_BWSEL                      0x10
  27 #define STK8BA50_REG_POWMODE                    0x11
  28 #define STK8BA50_REG_SWRST                      0x14
  29 #define STK8BA50_REG_INTEN2                     0x17
  30 #define STK8BA50_REG_INTMAP2                    0x1A
  31
  32 #define STK8BA50_MODE_NORMAL                    0
  33 #define STK8BA50_MODE_SUSPEND                   1
  34 #define STK8BA50_MODE_POWERBIT                  BIT(7)
  35 #define STK8BA50_DATA_SHIFT                     6
  36 #define STK8BA50_RESET_CMD                      0xB6
  37 #define STK8BA50_SR_1792HZ_IDX                  7
  38 #define STK8BA50_DREADY_INT_MASK                0x10
  39 #define STK8BA50_DREADY_INT_MAP                 0x81
  40 #define STK8BA50_ALL_CHANNEL_MASK               7
  41 #define STK8BA50_ALL_CHANNEL_SIZE               6
  42
  43 #define STK8BA50_DRIVER_NAME                    "stk8ba50"
  44 #define STK8BA50_IRQ_NAME                       "stk8ba50_event"
  45
  46 #define STK8BA50_SCALE_AVAIL                    "0.0384 0.0767 0.1534 0.3069"
  47
  48 /*
  49  * The accelerometer has four measurement ranges:
  50  * +/-2g; +/-4g; +/-8g; +/-16g
  51  *
  52  * Acceleration values are 10-bit, 2's complement.
  53  * Scales are calculated as following:
  54  *
  55  * scale1 = (2 + 2) * 9.81 / (2^10 - 1)   = 0.0384
  56  * scale2 = (4 + 4) * 9.81 / (2^10 - 1)   = 0.0767
  57  * etc.
  58  *
  59  * Scales are stored in this format:
  60  * { <register value>, <scale value> }
  61  *
  62  * Locally, the range is stored as a table index.
  63  */
  64 static const struct {
  65         u8 reg_val;
  66         u32 scale_val;
  67 } stk8ba50_scale_table[] = {
  68         {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
  69 };
  70
  71 /* Sample rates are stored as { <register value>, <Hz value> } */
  72 static const struct {
  73         u8 reg_val;
  74         u16 samp_freq;
  75 } stk8ba50_samp_freq_table[] = {
  76         {0x08, 14},  {0x09, 25},  {0x0A, 56},  {0x0B, 112},
  77         {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
  78 };
  79
  80 /* Used to map scan mask bits to their corresponding channel register. */
  81 static const int stk8ba50_channel_table[] = {
  82         STK8BA50_REG_XOUT,
  83         STK8BA50_REG_YOUT,
  84         STK8BA50_REG_ZOUT
  85 };
  86
  87 struct stk8ba50_data {
  88         struct i2c_client *client;
  89         struct mutex lock;
  90         int range;
  91         u8 sample_rate_idx;
  92         struct iio_trigger *dready_trig;
  93         bool dready_trigger_on;
  94         /* Ensure timestamp is naturally aligned */
  95         struct {
  96                 s16 chans[3];
  97                 s64 timetamp __aligned(8);
  98         } scan;
  99 };
 100
 101 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) {                      \
 102         .type = IIO_ACCEL,                                              \
 103         .address = reg,                                                 \
 104         .modified = 1,                                                  \
 105         .channel2 = IIO_MOD_##axis,                                     \
 106         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
 107         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
 108                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
 109         .scan_index = index,                                            \
 110         .scan_type = {                                                  \
 111                 .sign = 's',                                            \
 112                 .realbits = 10,                                         \
 113                 .storagebits = 16,                                      \
 114                 .shift = STK8BA50_DATA_SHIFT,                           \
 115                 .endianness = IIO_CPU,                                  \
 116         },                                                              \
 117 }
 118
 119 static const struct iio_chan_spec stk8ba50_channels[] = {
 120         STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
 121         STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
 122         STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
 123         IIO_CHAN_SOFT_TIMESTAMP(3),
 124 };
 125
 126 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
 127
 128 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
 129
 130 static struct attribute *stk8ba50_attributes[] = {
 131         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
 132         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 133         NULL,
 134 };
 135
 136 static const struct attribute_group stk8ba50_attribute_group = {
 137         .attrs = stk8ba50_attributes
 138 };
 139
 140 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
 141 {
 142         int ret;
 143         struct i2c_client *client = data->client;
 144
 145         ret = i2c_smbus_read_word_data(client, reg);
 146         if (ret < 0) {
 147                 dev_err(&client->dev, "register read failed\n");
 148                 return ret;
 149         }
 150
 151         return ret;
 152 }
 153
 154 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
 155                                                bool state)
 156 {
 157         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 158         struct stk8ba50_data *data = iio_priv(indio_dev);
 159         int ret;
 160
 161         if (state)
 162                 ret = i2c_smbus_write_byte_data(data->client,
 163                         STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
 164         else
 165                 ret = i2c_smbus_write_byte_data(data->client,
 166                         STK8BA50_REG_INTEN2, 0x00);
 167
 168         if (ret < 0)
 169                 dev_err(&data->client->dev, "failed to set trigger state\n");
 170         else
 171                 data->dready_trigger_on = state;
 172
 173         return ret;
 174 }
 175
 176 static const struct iio_trigger_ops stk8ba50_trigger_ops = {
 177         .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
 178 };
 179
 180 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
 181 {
 182         int ret;
 183         u8 masked_reg;
 184         struct i2c_client *client = data->client;
 185
 186         ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
 187         if (ret < 0)
 188                 goto exit_err;
 189
 190         if (mode)
 191                 masked_reg = ret | STK8BA50_MODE_POWERBIT;
 192         else
 193                 masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
 194
 195         ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
 196                                         masked_reg);
 197         if (ret < 0)
 198                 goto exit_err;
 199
 200         return ret;
 201
 202 exit_err:
 203         dev_err(&client->dev, "failed to change sensor mode\n");
 204         return ret;
 205 }
 206
 207 static int stk8ba50_read_raw(struct iio_dev *indio_dev,
 208                              struct iio_chan_spec const *chan,
 209                              int *val, int *val2, long mask)
 210 {
 211         struct stk8ba50_data *data = iio_priv(indio_dev);
 212         int ret;
 213
 214         switch (mask) {
 215         case IIO_CHAN_INFO_RAW:
 216                 if (iio_buffer_enabled(indio_dev))
 217                         return -EBUSY;
 218                 mutex_lock(&data->lock);
 219                 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
 220                 if (ret < 0) {
 221                         mutex_unlock(&data->lock);
 222                         return -EINVAL;
 223                 }
 224                 ret = stk8ba50_read_accel(data, chan->address);
 225                 if (ret < 0) {
 226                         stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 227                         mutex_unlock(&data->lock);
 228                         return -EINVAL;
 229                 }
 230                 *val = sign_extend32(ret >> chan->scan_type.shift,
 231                                      chan->scan_type.realbits - 1);
 232                 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 233                 mutex_unlock(&data->lock);
 234                 return IIO_VAL_INT;
 235         case IIO_CHAN_INFO_SCALE:
 236                 *val = 0;
 237                 *val2 = stk8ba50_scale_table[data->range].scale_val;
 238                 return IIO_VAL_INT_PLUS_MICRO;
 239         case IIO_CHAN_INFO_SAMP_FREQ:
 240                 *val = stk8ba50_samp_freq_table
 241                                 [data->sample_rate_idx].samp_freq;
 242                 *val2 = 0;
 243                 return IIO_VAL_INT;
 244         }
 245
 246         return -EINVAL;
 247 }
 248
 249 static int stk8ba50_write_raw(struct iio_dev *indio_dev,
 250                               struct iio_chan_spec const *chan,
 251                               int val, int val2, long mask)
 252 {
 253         int ret;
 254         int i;
 255         int index = -1;
 256         struct stk8ba50_data *data = iio_priv(indio_dev);
 257
 258         switch (mask) {
 259         case IIO_CHAN_INFO_SCALE:
 260                 if (val != 0)
 261                         return -EINVAL;
 262
 263                 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
 264                         if (val2 == stk8ba50_scale_table[i].scale_val) {
 265                                 index = i;
 266                                 break;
 267                         }
 268                 if (index < 0)
 269                         return -EINVAL;
 270
 271                 ret = i2c_smbus_write_byte_data(data->client,
 272                                 STK8BA50_REG_RANGE,
 273                                 stk8ba50_scale_table[index].reg_val);
 274                 if (ret < 0)
 275                         dev_err(&data->client->dev,
 276                                         "failed to set measurement range\n");
 277                 else
 278                         data->range = index;
 279
 280                 return ret;
 281         case IIO_CHAN_INFO_SAMP_FREQ:
 282                 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
 283                         if (val == stk8ba50_samp_freq_table[i].samp_freq) {
 284                                 index = i;
 285                                 break;
 286                         }
 287                 if (index < 0)
 288                         return -EINVAL;
 289
 290                 ret = i2c_smbus_write_byte_data(data->client,
 291                                 STK8BA50_REG_BWSEL,
 292                                 stk8ba50_samp_freq_table[index].reg_val);
 293                 if (ret < 0)
 294                         dev_err(&data->client->dev,
 295                                         "failed to set sampling rate\n");
 296                 else
 297                         data->sample_rate_idx = index;
 298
 299                 return ret;
 300         }
 301
 302         return -EINVAL;
 303 }
 304
 305 static const struct iio_info stk8ba50_info = {
 306         .read_raw               = stk8ba50_read_raw,
 307         .write_raw              = stk8ba50_write_raw,
 308         .attrs                  = &stk8ba50_attribute_group,
 309 };
 310
 311 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
 312 {
 313         struct iio_poll_func *pf = p;
 314         struct iio_dev *indio_dev = pf->indio_dev;
 315         struct stk8ba50_data *data = iio_priv(indio_dev);
 316         int bit, ret, i = 0;
 317
 318         mutex_lock(&data->lock);
 319         /*
 320          * Do a bulk read if all channels are requested,
 321          * from 0x02 (XOUT1) to 0x07 (ZOUT2)
 322          */
 323         if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
 324                 ret = i2c_smbus_read_i2c_block_data(data->client,
 325                                                     STK8BA50_REG_XOUT,
 326                                                     STK8BA50_ALL_CHANNEL_SIZE,
 327                                                     (u8 *)data->scan.chans);
 328                 if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
 329                         dev_err(&data->client->dev, "register read failed\n");
 330                         goto err;
 331                 }
 332         } else {
 333                 for_each_set_bit(bit, indio_dev->active_scan_mask,
 334                                  indio_dev->masklength) {
 335                         ret = stk8ba50_read_accel(data,
 336                                                   stk8ba50_channel_table[bit]);
 337                         if (ret < 0)
 338                                 goto err;
 339
 340                         data->scan.chans[i++] = ret;
 341                 }
 342         }
 343         iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
 344                                            pf->timestamp);
 345 err:
 346         mutex_unlock(&data->lock);
 347         iio_trigger_notify_done(indio_dev->trig);
 348
 349         return IRQ_HANDLED;
 350 }
 351
 352 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
 353 {
 354         struct iio_dev *indio_dev = private;
 355         struct stk8ba50_data *data = iio_priv(indio_dev);
 356
 357         if (data->dready_trigger_on)
 358                 iio_trigger_poll(data->dready_trig);
 359
 360         return IRQ_HANDLED;
 361 }
 362
 363 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
 364 {
 365         struct stk8ba50_data *data = iio_priv(indio_dev);
 366
 367         return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
 368 }
 369
 370 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
 371 {
 372         struct stk8ba50_data *data = iio_priv(indio_dev);
 373
 374         return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 375 }
 376
 377 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
 378         .preenable   = stk8ba50_buffer_preenable,
 379         .postdisable = stk8ba50_buffer_postdisable,
 380 };
 381
 382 static int stk8ba50_probe(struct i2c_client *client)
 383 {
 384         int ret;
 385         struct iio_dev *indio_dev;
 386         struct stk8ba50_data *data;
 387
 388         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 389         if (!indio_dev) {
 390                 dev_err(&client->dev, "iio allocation failed!\n");
 391                 return -ENOMEM;
 392         }
 393
 394         data = iio_priv(indio_dev);
 395         data->client = client;
 396         i2c_set_clientdata(client, indio_dev);
 397         mutex_init(&data->lock);
 398
 399         indio_dev->info = &stk8ba50_info;
 400         indio_dev->name = STK8BA50_DRIVER_NAME;
 401         indio_dev->modes = INDIO_DIRECT_MODE;
 402         indio_dev->channels = stk8ba50_channels;
 403         indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
 404
 405         /* Reset all registers on startup */
 406         ret = i2c_smbus_write_byte_data(client,
 407                         STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
 408         if (ret < 0) {
 409                 dev_err(&client->dev, "failed to reset sensor\n");
 410                 goto err_power_off;
 411         }
 412
 413         /* The default range is +/-2g */
 414         data->range = 0;
 415
 416         /* The default sampling rate is 1792 Hz (maximum) */
 417         data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
 418
 419         /* Set up interrupts */
 420         ret = i2c_smbus_write_byte_data(client,
 421                         STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
 422         if (ret < 0) {
 423                 dev_err(&client->dev, "failed to set up interrupts\n");
 424                 goto err_power_off;
 425         }
 426         ret = i2c_smbus_write_byte_data(client,
 427                         STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
 428         if (ret < 0) {
 429                 dev_err(&client->dev, "failed to set up interrupts\n");
 430                 goto err_power_off;
 431         }
 432
 433         if (client->irq > 0) {
 434                 ret = devm_request_threaded_irq(&client->dev, client->irq,
 435                                                 stk8ba50_data_rdy_trig_poll,
 436                                                 NULL,
 437                                                 IRQF_TRIGGER_RISING |
 438                                                 IRQF_ONESHOT,
 439                                                 STK8BA50_IRQ_NAME,
 440                                                 indio_dev);
 441                 if (ret < 0) {
 442                         dev_err(&client->dev, "request irq %d failed\n",
 443                                 client->irq);
 444                         goto err_power_off;
 445                 }
 446
 447                 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
 448                                                            "%s-dev%d",
 449                                                            indio_dev->name,
 450                                                            iio_device_id(indio_dev));
 451                 if (!data->dready_trig) {
 452                         ret = -ENOMEM;
 453                         goto err_power_off;
 454                 }
 455
 456                 data->dready_trig->ops = &stk8ba50_trigger_ops;
 457                 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
 458                 ret = iio_trigger_register(data->dready_trig);
 459                 if (ret) {
 460                         dev_err(&client->dev, "iio trigger register failed\n");
 461                         goto err_power_off;
 462                 }
 463         }
 464
 465         ret = iio_triggered_buffer_setup(indio_dev,
 466                                          iio_pollfunc_store_time,
 467                                          stk8ba50_trigger_handler,
 468                                          &stk8ba50_buffer_setup_ops);
 469         if (ret < 0) {
 470                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 471                 goto err_trigger_unregister;
 472         }
 473
 474         ret = iio_device_register(indio_dev);
 475         if (ret < 0) {
 476                 dev_err(&client->dev, "device_register failed\n");
 477                 goto err_buffer_cleanup;
 478         }
 479
 480         return ret;
 481
 482 err_buffer_cleanup:
 483         iio_triggered_buffer_cleanup(indio_dev);
 484 err_trigger_unregister:
 485         if (data->dready_trig)
 486                 iio_trigger_unregister(data->dready_trig);
 487 err_power_off:
 488         stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 489         return ret;
 490 }
 491
 492 static void stk8ba50_remove(struct i2c_client *client)
 493 {
 494         struct iio_dev *indio_dev = i2c_get_clientdata(client);
 495         struct stk8ba50_data *data = iio_priv(indio_dev);
 496
 497         iio_device_unregister(indio_dev);
 498         iio_triggered_buffer_cleanup(indio_dev);
 499
 500         if (data->dready_trig)
 501                 iio_trigger_unregister(data->dready_trig);
 502
 503         stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 504 }
 505
 506 static int stk8ba50_suspend(struct device *dev)
 507 {
 508         struct stk8ba50_data *data;
 509
 510         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 511
 512         return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 513 }
 514
 515 static int stk8ba50_resume(struct device *dev)
 516 {
 517         struct stk8ba50_data *data;
 518
 519         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
 520
 521         return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
 522 }
 523
 524 static DEFINE_SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend,
 525                                 stk8ba50_resume);
 526
 527 static const struct i2c_device_id stk8ba50_i2c_id[] = {
 528         {"stk8ba50", 0},
 529         {}
 530 };
 531 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
 532
 533 static const struct acpi_device_id stk8ba50_acpi_id[] = {
 534         {"STK8BA50", 0},
 535         {}
 536 };
 537
 538 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
 539
 540 static struct i2c_driver stk8ba50_driver = {
 541         .driver = {
 542                 .name = "stk8ba50",
 543                 .pm = pm_sleep_ptr(&stk8ba50_pm_ops),
 544                 .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
 545         },
 546         .probe_new =        stk8ba50_probe,
 547         .remove =           stk8ba50_remove,
 548         .id_table =         stk8ba50_i2c_id,
 549 };
 550
 551 module_i2c_driver(stk8ba50_driver);
 552
 553 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
 554 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
 555 MODULE_LICENSE("GPL v2");