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/i2c.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/mod_devicetable.h>
  15 #include <linux/types.h>
  16 #include <linux/iio/buffer.h>
  17 #include <linux/iio/iio.h>
  18 #include <linux/iio/sysfs.h>
  19 #include <linux/iio/trigger.h>
  20 #include <linux/iio/triggered_buffer.h>
  21 #include <linux/iio/trigger_consumer.h>
  22
  23 #define STK8BA50_REG_XOUT                       0x02
  24 #define STK8BA50_REG_YOUT                       0x04
  25 #define STK8BA50_REG_ZOUT                       0x06
  26 #define STK8BA50_REG_RANGE                      0x0F
  27 #define STK8BA50_REG_BWSEL                      0x10
  28 #define STK8BA50_REG_POWMODE                    0x11
  29 #define STK8BA50_REG_SWRST                      0x14
  30 #define STK8BA50_REG_INTEN2                     0x17
  31 #define STK8BA50_REG_INTMAP2                    0x1A
  32
  33 #define STK8BA50_MODE_NORMAL                    0
  34 #define STK8BA50_MODE_SUSPEND                   1
  35 #define STK8BA50_MODE_POWERBIT                  BIT(7)
  36 #define STK8BA50_DATA_SHIFT                     6
  37 #define STK8BA50_RESET_CMD                      0xB6
  38 #define STK8BA50_SR_1792HZ_IDX                  7
  39 #define STK8BA50_DREADY_INT_MASK                0x10
  40 #define STK8BA50_DREADY_INT_MAP                 0x81
  41 #define STK8BA50_ALL_CHANNEL_MASK               7
  42 #define STK8BA50_ALL_CHANNEL_SIZE               6
  43
  44 #define STK8BA50_DRIVER_NAME                    "stk8ba50"
  45 #define STK8BA50_IRQ_NAME                       "stk8ba50_event"
  46
  47 #define STK8BA50_SCALE_AVAIL                    "0.0384 0.0767 0.1534 0.3069"
  48
  49 /*
  50  * The accelerometer has four measurement ranges:
  51  * +/-2g; +/-4g; +/-8g; +/-16g
  52  *
  53  * Acceleration values are 10-bit, 2's complement.
  54  * Scales are calculated as following:
  55  *
  56  * scale1 = (2 + 2) * 9.81 / (2^10 - 1)   = 0.0384
  57  * scale2 = (4 + 4) * 9.81 / (2^10 - 1)   = 0.0767
  58  * etc.
  59  *
  60  * Scales are stored in this format:
  61  * { <register value>, <scale value> }
  62  *
  63  * Locally, the range is stored as a table index.
  64  */
  65 static const struct {
  66         u8 reg_val;
  67         u32 scale_val;
  68 } stk8ba50_scale_table[] = {
  69         {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
  70 };
  71
  72 /* Sample rates are stored as { <register value>, <Hz value> } */
  73 static const struct {
  74         u8 reg_val;
  75         u16 samp_freq;
  76 } stk8ba50_samp_freq_table[] = {
  77         {0x08, 14},  {0x09, 25},  {0x0A, 56},  {0x0B, 112},
  78         {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
  79 };
  80
  81 /* Used to map scan mask bits to their corresponding channel register. */
  82 static const int stk8ba50_channel_table[] = {
  83         STK8BA50_REG_XOUT,
  84         STK8BA50_REG_YOUT,
  85         STK8BA50_REG_ZOUT
  86 };
  87
  88 struct stk8ba50_data {
  89         struct i2c_client *client;
  90         struct mutex lock;
  91         int range;
  92         u8 sample_rate_idx;
  93         struct iio_trigger *dready_trig;
  94         bool dready_trigger_on;
  95         /* Ensure timestamp is naturally aligned */
  96         struct {
  97                 s16 chans[3];
  98                 aligned_s64 timetamp;
  99         } scan;
 100 };
 101
 102 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) {                      \
 103         .type = IIO_ACCEL,                                              \
 104         .address = reg,                                                 \
 105         .modified = 1,                                                  \
 106         .channel2 = IIO_MOD_##axis,                                     \
 107         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
 108         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),           \
 109                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
 110         .scan_index = index,                                            \
 111         .scan_type = {                                                  \
 112                 .sign = 's',                                            \
 113                 .realbits = 10,                                         \
 114                 .storagebits = 16,                                      \
 115                 .shift = STK8BA50_DATA_SHIFT,                           \
 116                 .endianness = IIO_CPU,                                  \
 117         },                                                              \
 118 }
 119
 120 static const struct iio_chan_spec stk8ba50_channels[] = {
 121         STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
 122         STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
 123         STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
 124         IIO_CHAN_SOFT_TIMESTAMP(3),
 125 };
 126
 127 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
 128
 129 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
 130
 131 static struct attribute *stk8ba50_attributes[] = {
 132         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
 133         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
 134         NULL,
 135 };
 136
 137 static const struct attribute_group stk8ba50_attribute_group = {
 138         .attrs = stk8ba50_attributes
 139 };
 140
 141 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
 142 {
 143         int ret;
 144         struct i2c_client *client = data->client;
 145
 146         ret = i2c_smbus_read_word_data(client, reg);
 147         if (ret < 0) {
 148                 dev_err(&client->dev, "register read failed\n");
 149                 return ret;
 150         }
 151
 152         return ret;
 153 }
 154
 155 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
 156                                                bool state)
 157 {
 158         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
 159         struct stk8ba50_data *data = iio_priv(indio_dev);
 160         int ret;
 161
 162         if (state)
 163                 ret = i2c_smbus_write_byte_data(data->client,
 164                         STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
 165         else
 166                 ret = i2c_smbus_write_byte_data(data->client,
 167                         STK8BA50_REG_INTEN2, 0x00);
 168
 169         if (ret < 0)
 170                 dev_err(&data->client->dev, "failed to set trigger state\n");
 171         else
 172                 data->dready_trigger_on = state;
 173
 174         return ret;
 175 }
 176
 177 static const struct iio_trigger_ops stk8ba50_trigger_ops = {
 178         .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
 179 };
 180
 181 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
 182 {
 183         int ret;
 184         u8 masked_reg;
 185         struct i2c_client *client = data->client;
 186
 187         ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
 188         if (ret < 0)
 189                 goto exit_err;
 190
 191         if (mode)
 192                 masked_reg = ret | STK8BA50_MODE_POWERBIT;
 193         else
 194                 masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
 195
 196         ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
 197                                         masked_reg);
 198         if (ret < 0)
 199                 goto exit_err;
 200
 201         return ret;
 202
 203 exit_err:
 204         dev_err(&client->dev, "failed to change sensor mode\n");
 205         return ret;
 206 }
 207
 208 static int stk8ba50_read_raw(struct iio_dev *indio_dev,
 209                              struct iio_chan_spec const *chan,
 210                              int *val, int *val2, long mask)
 211 {
 212         struct stk8ba50_data *data = iio_priv(indio_dev);
 213         int ret;
 214
 215         switch (mask) {
 216         case IIO_CHAN_INFO_RAW:
 217                 if (iio_buffer_enabled(indio_dev))
 218                         return -EBUSY;
 219                 mutex_lock(&data->lock);
 220                 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
 221                 if (ret < 0) {
 222                         mutex_unlock(&data->lock);
 223                         return -EINVAL;
 224                 }
 225                 ret = stk8ba50_read_accel(data, chan->address);
 226                 if (ret < 0) {
 227                         stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 228                         mutex_unlock(&data->lock);
 229                         return -EINVAL;
 230                 }
 231                 *val = sign_extend32(ret >> chan->scan_type.shift,
 232                                      chan->scan_type.realbits - 1);
 233                 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
 234                 mutex_unlock(&data->lock);
 235                 return IIO_VAL_INT;
 236         case IIO_CHAN_INFO_SCALE:
 237                 *val = 0;
 238                 *val2 = stk8ba50_scale_table[data->range].scale_val;
 239                 return IIO_VAL_INT_PLUS_MICRO;
 240         case IIO_CHAN_INFO_SAMP_FREQ:
 241                 *val = stk8ba50_samp_freq_table
 242                                 [data->sample_rate_idx].samp_freq;
 243                 *val2 = 0;
 244                 return IIO_VAL_INT;
 245         }
 246
 247         return -EINVAL;
 248 }
 249
 250 static int stk8ba50_write_raw(struct iio_dev *indio_dev,
 251                               struct iio_chan_spec const *chan,
 252                               int val, int val2, long mask)
 253 {
 254         int ret;
 255         int i;
 256         int index = -1;
 257         struct stk8ba50_data *data = iio_priv(indio_dev);
 258
 259         switch (mask) {
 260         case IIO_CHAN_INFO_SCALE:
 261                 if (val != 0)
 262                         return -EINVAL;
 263
 264                 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
 265                         if (val2 == stk8ba50_scale_table[i].scale_val) {
 266                                 index = i;
 267                                 break;
 268                         }
 269                 if (index < 0)
 270                         return -EINVAL;
 271
 272                 ret = i2c_smbus_write_byte_data(data->client,
 273                                 STK8BA50_REG_RANGE,
 274                                 stk8ba50_scale_table[index].reg_val);
 275                 if (ret < 0)
 276                         dev_err(&data->client->dev,
 277                                         "failed to set measurement range\n");
 278                 else
 279                         data->range = index;
 280
 281                 return ret;
 282         case IIO_CHAN_INFO_SAMP_FREQ:
 283                 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
 284                         if (val == stk8ba50_samp_freq_table[i].samp_freq) {
 285                                 index = i;
 286                                 break;
 287                         }
 288                 if (index < 0)
 289                         return -EINVAL;
 290
 291                 ret = i2c_smbus_write_byte_data(data->client,
 292                                 STK8BA50_REG_BWSEL,
 293                                 stk8ba50_samp_freq_table[index].reg_val);
 294                 if (ret < 0)
 295                         dev_err(&data->client->dev,
 296                                         "failed to set sampling rate\n");
 297                 else
 298                         data->sample_rate_idx = index;
 299
 300                 return ret;
 301         }
 302
 303         return -EINVAL;
 304 }
 305
 306 static const struct iio_info stk8ba50_info = {
 307         .read_raw               = stk8ba50_read_raw,
 308         .write_raw              = stk8ba50_write_raw,
 309         .attrs                  = &stk8ba50_attribute_group,
 310 };
 311
 312 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
 313 {
 314         struct iio_poll_func *pf = p;
 315         struct iio_dev *indio_dev = pf->indio_dev;
 316         struct stk8ba50_data *data = iio_priv(indio_dev);
 317         int bit, ret, i = 0;
 318
 319         mutex_lock(&data->lock);
 320         /*
 321          * Do a bulk read if all channels are requested,
 322          * from 0x02 (XOUT1) to 0x07 (ZOUT2)
 323          */
 324         if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
 325                 ret = i2c_smbus_read_i2c_block_data(data->client,
 326                                                     STK8BA50_REG_XOUT,
 327                                                     STK8BA50_ALL_CHANNEL_SIZE,
 328                                                     (u8 *)data->scan.chans);
 329                 if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
 330                         dev_err(&data->client->dev, "register read failed\n");
 331                         goto err;
 332                 }
 333         } else {
 334                 iio_for_each_active_channel(indio_dev, bit) {
 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" },
 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 = stk8ba50_acpi_id,
 545         },
 546         .probe =        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 <[email protected]>");
 554 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
 555 MODULE_LICENSE("GPL v2");