1 /** 2 * Sensortek STK8BA50 3-Axis Accelerometer 3 * 4 * Copyright (c) 2015, Intel Corporation. 5 * 6 * This file is subject to the terms and conditions of version 2 of 7 * the GNU General Public License. See the file COPYING in the main 8 * directory of this archive for more details. 9 * 10 * STK8BA50 7-bit I2C address: 0x18. 11 */ 12 13 #include <linux/acpi.h> 14 #include <linux/i2c.h> 15 #include <linux/interrupt.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/iio/buffer.h> 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 #include <linux/iio/trigger.h> 22 #include <linux/iio/triggered_buffer.h> 23 #include <linux/iio/trigger_consumer.h> 24 25 #define STK8BA50_REG_XOUT 0x02 26 #define STK8BA50_REG_YOUT 0x04 27 #define STK8BA50_REG_ZOUT 0x06 28 #define STK8BA50_REG_RANGE 0x0F 29 #define STK8BA50_REG_BWSEL 0x10 30 #define STK8BA50_REG_POWMODE 0x11 31 #define STK8BA50_REG_SWRST 0x14 32 #define STK8BA50_REG_INTEN2 0x17 33 #define STK8BA50_REG_INTMAP2 0x1A 34 35 #define STK8BA50_MODE_NORMAL 0 36 #define STK8BA50_MODE_SUSPEND 1 37 #define STK8BA50_MODE_POWERBIT BIT(7) 38 #define STK8BA50_DATA_SHIFT 6 39 #define STK8BA50_RESET_CMD 0xB6 40 #define STK8BA50_SR_1792HZ_IDX 7 41 #define STK8BA50_DREADY_INT_MASK 0x10 42 #define STK8BA50_DREADY_INT_MAP 0x81 43 #define STK8BA50_ALL_CHANNEL_MASK 7 44 #define STK8BA50_ALL_CHANNEL_SIZE 6 45 46 #define STK8BA50_DRIVER_NAME "stk8ba50" 47 #define STK8BA50_IRQ_NAME "stk8ba50_event" 48 49 #define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069" 50 51 /* 52 * The accelerometer has four measurement ranges: 53 * +/-2g; +/-4g; +/-8g; +/-16g 54 * 55 * Acceleration values are 10-bit, 2's complement. 56 * Scales are calculated as following: 57 * 58 * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384 59 * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767 60 * etc. 61 * 62 * Scales are stored in this format: 63 * { <register value>, <scale value> } 64 * 65 * Locally, the range is stored as a table index. 66 */ 67 static const struct { 68 u8 reg_val; 69 u32 scale_val; 70 } stk8ba50_scale_table[] = { 71 {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900} 72 }; 73 74 /* Sample rates are stored as { <register value>, <Hz value> } */ 75 static const struct { 76 u8 reg_val; 77 u16 samp_freq; 78 } stk8ba50_samp_freq_table[] = { 79 {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112}, 80 {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792} 81 }; 82 83 /* Used to map scan mask bits to their corresponding channel register. */ 84 static const int stk8ba50_channel_table[] = { 85 STK8BA50_REG_XOUT, 86 STK8BA50_REG_YOUT, 87 STK8BA50_REG_ZOUT 88 }; 89 90 struct stk8ba50_data { 91 struct i2c_client *client; 92 struct mutex lock; 93 int range; 94 u8 sample_rate_idx; 95 struct iio_trigger *dready_trig; 96 bool dready_trigger_on; 97 /* 98 * 3 x 16-bit channels (10-bit data, 6-bit padding) + 99 * 1 x 16 padding + 100 * 4 x 16 64-bit timestamp 101 */ 102 s16 buffer[8]; 103 }; 104 105 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \ 106 .type = IIO_ACCEL, \ 107 .address = reg, \ 108 .modified = 1, \ 109 .channel2 = IIO_MOD_##axis, \ 110 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 111 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 112 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 113 .scan_index = index, \ 114 .scan_type = { \ 115 .sign = 's', \ 116 .realbits = 10, \ 117 .storagebits = 16, \ 118 .shift = STK8BA50_DATA_SHIFT, \ 119 .endianness = IIO_CPU, \ 120 }, \ 121 } 122 123 static const struct iio_chan_spec stk8ba50_channels[] = { 124 STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X), 125 STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y), 126 STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z), 127 IIO_CHAN_SOFT_TIMESTAMP(3), 128 }; 129 130 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL); 131 132 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792"); 133 134 static struct attribute *stk8ba50_attributes[] = { 135 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 136 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 137 NULL, 138 }; 139 140 static const struct attribute_group stk8ba50_attribute_group = { 141 .attrs = stk8ba50_attributes 142 }; 143 144 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg) 145 { 146 int ret; 147 struct i2c_client *client = data->client; 148 149 ret = i2c_smbus_read_word_data(client, reg); 150 if (ret < 0) { 151 dev_err(&client->dev, "register read failed\n"); 152 return ret; 153 } 154 155 return ret; 156 } 157 158 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig, 159 bool state) 160 { 161 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 162 struct stk8ba50_data *data = iio_priv(indio_dev); 163 int ret; 164 165 if (state) 166 ret = i2c_smbus_write_byte_data(data->client, 167 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); 168 else 169 ret = i2c_smbus_write_byte_data(data->client, 170 STK8BA50_REG_INTEN2, 0x00); 171 172 if (ret < 0) 173 dev_err(&data->client->dev, "failed to set trigger state\n"); 174 else 175 data->dready_trigger_on = state; 176 177 return ret; 178 } 179 180 static const struct iio_trigger_ops stk8ba50_trigger_ops = { 181 .set_trigger_state = stk8ba50_data_rdy_trigger_set_state, 182 .owner = THIS_MODULE, 183 }; 184 185 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode) 186 { 187 int ret; 188 u8 masked_reg; 189 struct i2c_client *client = data->client; 190 191 ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE); 192 if (ret < 0) 193 goto exit_err; 194 195 if (mode) 196 masked_reg = ret | STK8BA50_MODE_POWERBIT; 197 else 198 masked_reg = ret & (~STK8BA50_MODE_POWERBIT); 199 200 ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE, 201 masked_reg); 202 if (ret < 0) 203 goto exit_err; 204 205 return ret; 206 207 exit_err: 208 dev_err(&client->dev, "failed to change sensor mode\n"); 209 return ret; 210 } 211 212 static int stk8ba50_read_raw(struct iio_dev *indio_dev, 213 struct iio_chan_spec const *chan, 214 int *val, int *val2, long mask) 215 { 216 struct stk8ba50_data *data = iio_priv(indio_dev); 217 int ret; 218 219 switch (mask) { 220 case IIO_CHAN_INFO_RAW: 221 if (iio_buffer_enabled(indio_dev)) 222 return -EBUSY; 223 mutex_lock(&data->lock); 224 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 225 if (ret < 0) { 226 mutex_unlock(&data->lock); 227 return -EINVAL; 228 } 229 ret = stk8ba50_read_accel(data, chan->address); 230 if (ret < 0) { 231 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 232 mutex_unlock(&data->lock); 233 return -EINVAL; 234 } 235 *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9); 236 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 237 mutex_unlock(&data->lock); 238 return IIO_VAL_INT; 239 case IIO_CHAN_INFO_SCALE: 240 *val = 0; 241 *val2 = stk8ba50_scale_table[data->range].scale_val; 242 return IIO_VAL_INT_PLUS_MICRO; 243 case IIO_CHAN_INFO_SAMP_FREQ: 244 *val = stk8ba50_samp_freq_table 245 [data->sample_rate_idx].samp_freq; 246 *val2 = 0; 247 return IIO_VAL_INT; 248 } 249 250 return -EINVAL; 251 } 252 253 static int stk8ba50_write_raw(struct iio_dev *indio_dev, 254 struct iio_chan_spec const *chan, 255 int val, int val2, long mask) 256 { 257 int ret; 258 int i; 259 int index = -1; 260 struct stk8ba50_data *data = iio_priv(indio_dev); 261 262 switch (mask) { 263 case IIO_CHAN_INFO_SCALE: 264 if (val != 0) 265 return -EINVAL; 266 267 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++) 268 if (val2 == stk8ba50_scale_table[i].scale_val) { 269 index = i; 270 break; 271 } 272 if (index < 0) 273 return -EINVAL; 274 275 ret = i2c_smbus_write_byte_data(data->client, 276 STK8BA50_REG_RANGE, 277 stk8ba50_scale_table[index].reg_val); 278 if (ret < 0) 279 dev_err(&data->client->dev, 280 "failed to set measurement range\n"); 281 else 282 data->range = index; 283 284 return ret; 285 case IIO_CHAN_INFO_SAMP_FREQ: 286 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++) 287 if (val == stk8ba50_samp_freq_table[i].samp_freq) { 288 index = i; 289 break; 290 } 291 if (index < 0) 292 return -EINVAL; 293 294 ret = i2c_smbus_write_byte_data(data->client, 295 STK8BA50_REG_BWSEL, 296 stk8ba50_samp_freq_table[index].reg_val); 297 if (ret < 0) 298 dev_err(&data->client->dev, 299 "failed to set sampling rate\n"); 300 else 301 data->sample_rate_idx = index; 302 303 return ret; 304 } 305 306 return -EINVAL; 307 } 308 309 static const struct iio_info stk8ba50_info = { 310 .driver_module = THIS_MODULE, 311 .read_raw = stk8ba50_read_raw, 312 .write_raw = stk8ba50_write_raw, 313 .attrs = &stk8ba50_attribute_group, 314 }; 315 316 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p) 317 { 318 struct iio_poll_func *pf = p; 319 struct iio_dev *indio_dev = pf->indio_dev; 320 struct stk8ba50_data *data = iio_priv(indio_dev); 321 int bit, ret, i = 0; 322 323 mutex_lock(&data->lock); 324 /* 325 * Do a bulk read if all channels are requested, 326 * from 0x02 (XOUT1) to 0x07 (ZOUT2) 327 */ 328 if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) { 329 ret = i2c_smbus_read_i2c_block_data(data->client, 330 STK8BA50_REG_XOUT, 331 STK8BA50_ALL_CHANNEL_SIZE, 332 (u8 *)data->buffer); 333 if (ret < STK8BA50_ALL_CHANNEL_SIZE) { 334 dev_err(&data->client->dev, "register read failed\n"); 335 goto err; 336 } 337 } else { 338 for_each_set_bit(bit, indio_dev->active_scan_mask, 339 indio_dev->masklength) { 340 ret = stk8ba50_read_accel(data, 341 stk8ba50_channel_table[bit]); 342 if (ret < 0) 343 goto err; 344 345 data->buffer[i++] = ret; 346 } 347 } 348 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 349 pf->timestamp); 350 err: 351 mutex_unlock(&data->lock); 352 iio_trigger_notify_done(indio_dev->trig); 353 354 return IRQ_HANDLED; 355 } 356 357 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private) 358 { 359 struct iio_dev *indio_dev = private; 360 struct stk8ba50_data *data = iio_priv(indio_dev); 361 362 if (data->dready_trigger_on) 363 iio_trigger_poll(data->dready_trig); 364 365 return IRQ_HANDLED; 366 } 367 368 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev) 369 { 370 struct stk8ba50_data *data = iio_priv(indio_dev); 371 372 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 373 } 374 375 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev) 376 { 377 struct stk8ba50_data *data = iio_priv(indio_dev); 378 379 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 380 } 381 382 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = { 383 .preenable = stk8ba50_buffer_preenable, 384 .postenable = iio_triggered_buffer_postenable, 385 .predisable = iio_triggered_buffer_predisable, 386 .postdisable = stk8ba50_buffer_postdisable, 387 }; 388 389 static int stk8ba50_probe(struct i2c_client *client, 390 const struct i2c_device_id *id) 391 { 392 int ret; 393 struct iio_dev *indio_dev; 394 struct stk8ba50_data *data; 395 396 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 397 if (!indio_dev) { 398 dev_err(&client->dev, "iio allocation failed!\n"); 399 return -ENOMEM; 400 } 401 402 data = iio_priv(indio_dev); 403 data->client = client; 404 i2c_set_clientdata(client, indio_dev); 405 mutex_init(&data->lock); 406 407 indio_dev->dev.parent = &client->dev; 408 indio_dev->info = &stk8ba50_info; 409 indio_dev->name = STK8BA50_DRIVER_NAME; 410 indio_dev->modes = INDIO_DIRECT_MODE; 411 indio_dev->channels = stk8ba50_channels; 412 indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels); 413 414 /* Reset all registers on startup */ 415 ret = i2c_smbus_write_byte_data(client, 416 STK8BA50_REG_SWRST, STK8BA50_RESET_CMD); 417 if (ret < 0) { 418 dev_err(&client->dev, "failed to reset sensor\n"); 419 goto err_power_off; 420 } 421 422 /* The default range is +/-2g */ 423 data->range = 0; 424 425 /* The default sampling rate is 1792 Hz (maximum) */ 426 data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX; 427 428 /* Set up interrupts */ 429 ret = i2c_smbus_write_byte_data(client, 430 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); 431 if (ret < 0) { 432 dev_err(&client->dev, "failed to set up interrupts\n"); 433 goto err_power_off; 434 } 435 ret = i2c_smbus_write_byte_data(client, 436 STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP); 437 if (ret < 0) { 438 dev_err(&client->dev, "failed to set up interrupts\n"); 439 goto err_power_off; 440 } 441 442 if (client->irq > 0) { 443 ret = devm_request_threaded_irq(&client->dev, client->irq, 444 stk8ba50_data_rdy_trig_poll, 445 NULL, 446 IRQF_TRIGGER_RISING | 447 IRQF_ONESHOT, 448 STK8BA50_IRQ_NAME, 449 indio_dev); 450 if (ret < 0) { 451 dev_err(&client->dev, "request irq %d failed\n", 452 client->irq); 453 goto err_power_off; 454 } 455 456 data->dready_trig = devm_iio_trigger_alloc(&client->dev, 457 "%s-dev%d", 458 indio_dev->name, 459 indio_dev->id); 460 if (!data->dready_trig) { 461 ret = -ENOMEM; 462 goto err_power_off; 463 } 464 465 data->dready_trig->dev.parent = &client->dev; 466 data->dready_trig->ops = &stk8ba50_trigger_ops; 467 iio_trigger_set_drvdata(data->dready_trig, indio_dev); 468 ret = iio_trigger_register(data->dready_trig); 469 if (ret) { 470 dev_err(&client->dev, "iio trigger register failed\n"); 471 goto err_power_off; 472 } 473 } 474 475 ret = iio_triggered_buffer_setup(indio_dev, 476 iio_pollfunc_store_time, 477 stk8ba50_trigger_handler, 478 &stk8ba50_buffer_setup_ops); 479 if (ret < 0) { 480 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 481 goto err_trigger_unregister; 482 } 483 484 ret = iio_device_register(indio_dev); 485 if (ret < 0) { 486 dev_err(&client->dev, "device_register failed\n"); 487 goto err_buffer_cleanup; 488 } 489 490 return ret; 491 492 err_buffer_cleanup: 493 iio_triggered_buffer_cleanup(indio_dev); 494 err_trigger_unregister: 495 if (data->dready_trig) 496 iio_trigger_unregister(data->dready_trig); 497 err_power_off: 498 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 499 return ret; 500 } 501 502 static int stk8ba50_remove(struct i2c_client *client) 503 { 504 struct iio_dev *indio_dev = i2c_get_clientdata(client); 505 struct stk8ba50_data *data = iio_priv(indio_dev); 506 507 iio_device_unregister(indio_dev); 508 iio_triggered_buffer_cleanup(indio_dev); 509 510 if (data->dready_trig) 511 iio_trigger_unregister(data->dready_trig); 512 513 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 514 } 515 516 #ifdef CONFIG_PM_SLEEP 517 static int stk8ba50_suspend(struct device *dev) 518 { 519 struct stk8ba50_data *data; 520 521 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 522 523 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 524 } 525 526 static int stk8ba50_resume(struct device *dev) 527 { 528 struct stk8ba50_data *data; 529 530 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 531 532 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 533 } 534 535 static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume); 536 537 #define STK8BA50_PM_OPS (&stk8ba50_pm_ops) 538 #else 539 #define STK8BA50_PM_OPS NULL 540 #endif 541 542 static const struct i2c_device_id stk8ba50_i2c_id[] = { 543 {"stk8ba50", 0}, 544 {} 545 }; 546 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id); 547 548 static const struct acpi_device_id stk8ba50_acpi_id[] = { 549 {"STK8BA50", 0}, 550 {} 551 }; 552 553 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id); 554 555 static struct i2c_driver stk8ba50_driver = { 556 .driver = { 557 .name = "stk8ba50", 558 .pm = STK8BA50_PM_OPS, 559 .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id), 560 }, 561 .probe = stk8ba50_probe, 562 .remove = stk8ba50_remove, 563 .id_table = stk8ba50_i2c_id, 564 }; 565 566 module_i2c_driver(stk8ba50_driver); 567 568 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 569 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver"); 570 MODULE_LICENSE("GPL v2"); 571