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/gpio/consumer.h> 15 #include <linux/i2c.h> 16 #include <linux/interrupt.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/iio/buffer.h> 20 #include <linux/iio/iio.h> 21 #include <linux/iio/sysfs.h> 22 #include <linux/iio/trigger.h> 23 #include <linux/iio/triggered_buffer.h> 24 #include <linux/iio/trigger_consumer.h> 25 26 #define STK8BA50_REG_XOUT 0x02 27 #define STK8BA50_REG_YOUT 0x04 28 #define STK8BA50_REG_ZOUT 0x06 29 #define STK8BA50_REG_RANGE 0x0F 30 #define STK8BA50_REG_BWSEL 0x10 31 #define STK8BA50_REG_POWMODE 0x11 32 #define STK8BA50_REG_SWRST 0x14 33 #define STK8BA50_REG_INTEN2 0x17 34 #define STK8BA50_REG_INTMAP2 0x1A 35 36 #define STK8BA50_MODE_NORMAL 0 37 #define STK8BA50_MODE_SUSPEND 1 38 #define STK8BA50_MODE_POWERBIT BIT(7) 39 #define STK8BA50_DATA_SHIFT 6 40 #define STK8BA50_RESET_CMD 0xB6 41 #define STK8BA50_SR_1792HZ_IDX 7 42 #define STK8BA50_DREADY_INT_MASK 0x10 43 #define STK8BA50_DREADY_INT_MAP 0x81 44 #define STK8BA50_ALL_CHANNEL_MASK 7 45 #define STK8BA50_ALL_CHANNEL_SIZE 6 46 47 #define STK8BA50_DRIVER_NAME "stk8ba50" 48 #define STK8BA50_IRQ_NAME "stk8ba50_event" 49 50 #define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069" 51 52 /* 53 * The accelerometer has four measurement ranges: 54 * +/-2g; +/-4g; +/-8g; +/-16g 55 * 56 * Acceleration values are 10-bit, 2's complement. 57 * Scales are calculated as following: 58 * 59 * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384 60 * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767 61 * etc. 62 * 63 * Scales are stored in this format: 64 * { <register value>, <scale value> } 65 * 66 * Locally, the range is stored as a table index. 67 */ 68 static const struct { 69 u8 reg_val; 70 u32 scale_val; 71 } stk8ba50_scale_table[] = { 72 {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900} 73 }; 74 75 /* Sample rates are stored as { <register value>, <Hz value> } */ 76 static const struct { 77 u8 reg_val; 78 u16 samp_freq; 79 } stk8ba50_samp_freq_table[] = { 80 {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112}, 81 {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792} 82 }; 83 84 /* Used to map scan mask bits to their corresponding channel register. */ 85 static const int stk8ba50_channel_table[] = { 86 STK8BA50_REG_XOUT, 87 STK8BA50_REG_YOUT, 88 STK8BA50_REG_ZOUT 89 }; 90 91 struct stk8ba50_data { 92 struct i2c_client *client; 93 struct mutex lock; 94 int range; 95 u8 sample_rate_idx; 96 struct iio_trigger *dready_trig; 97 bool dready_trigger_on; 98 /* 99 * 3 x 16-bit channels (10-bit data, 6-bit padding) + 100 * 1 x 16 padding + 101 * 4 x 16 64-bit timestamp 102 */ 103 s16 buffer[8]; 104 }; 105 106 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \ 107 .type = IIO_ACCEL, \ 108 .address = reg, \ 109 .modified = 1, \ 110 .channel2 = IIO_MOD_##axis, \ 111 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 112 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 113 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 114 .scan_index = index, \ 115 .scan_type = { \ 116 .sign = 's', \ 117 .realbits = 10, \ 118 .storagebits = 16, \ 119 .shift = STK8BA50_DATA_SHIFT, \ 120 .endianness = IIO_CPU, \ 121 }, \ 122 } 123 124 static const struct iio_chan_spec stk8ba50_channels[] = { 125 STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X), 126 STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y), 127 STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z), 128 IIO_CHAN_SOFT_TIMESTAMP(3), 129 }; 130 131 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL); 132 133 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792"); 134 135 static struct attribute *stk8ba50_attributes[] = { 136 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 137 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 138 NULL, 139 }; 140 141 static const struct attribute_group stk8ba50_attribute_group = { 142 .attrs = stk8ba50_attributes 143 }; 144 145 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg) 146 { 147 int ret; 148 struct i2c_client *client = data->client; 149 150 ret = i2c_smbus_read_word_data(client, reg); 151 if (ret < 0) { 152 dev_err(&client->dev, "register read failed\n"); 153 return ret; 154 } 155 156 return ret; 157 } 158 159 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig, 160 bool state) 161 { 162 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 163 struct stk8ba50_data *data = iio_priv(indio_dev); 164 int ret; 165 166 if (state) 167 ret = i2c_smbus_write_byte_data(data->client, 168 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); 169 else 170 ret = i2c_smbus_write_byte_data(data->client, 171 STK8BA50_REG_INTEN2, 0x00); 172 173 if (ret < 0) 174 dev_err(&data->client->dev, "failed to set trigger state\n"); 175 else 176 data->dready_trigger_on = state; 177 178 return ret; 179 } 180 181 static const struct iio_trigger_ops stk8ba50_trigger_ops = { 182 .set_trigger_state = stk8ba50_data_rdy_trigger_set_state, 183 .owner = THIS_MODULE, 184 }; 185 186 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode) 187 { 188 int ret; 189 u8 masked_reg; 190 struct i2c_client *client = data->client; 191 192 ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE); 193 if (ret < 0) 194 goto exit_err; 195 196 if (mode) 197 masked_reg = ret | STK8BA50_MODE_POWERBIT; 198 else 199 masked_reg = ret & (~STK8BA50_MODE_POWERBIT); 200 201 ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE, 202 masked_reg); 203 if (ret < 0) 204 goto exit_err; 205 206 return ret; 207 208 exit_err: 209 dev_err(&client->dev, "failed to change sensor mode\n"); 210 return ret; 211 } 212 213 static int stk8ba50_read_raw(struct iio_dev *indio_dev, 214 struct iio_chan_spec const *chan, 215 int *val, int *val2, long mask) 216 { 217 struct stk8ba50_data *data = iio_priv(indio_dev); 218 int ret; 219 220 switch (mask) { 221 case IIO_CHAN_INFO_RAW: 222 if (iio_buffer_enabled(indio_dev)) 223 return -EBUSY; 224 mutex_lock(&data->lock); 225 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 226 if (ret < 0) { 227 mutex_unlock(&data->lock); 228 return -EINVAL; 229 } 230 ret = stk8ba50_read_accel(data, chan->address); 231 if (ret < 0) { 232 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 233 mutex_unlock(&data->lock); 234 return -EINVAL; 235 } 236 *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9); 237 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 238 mutex_unlock(&data->lock); 239 return IIO_VAL_INT; 240 case IIO_CHAN_INFO_SCALE: 241 *val = 0; 242 *val2 = stk8ba50_scale_table[data->range].scale_val; 243 return IIO_VAL_INT_PLUS_MICRO; 244 case IIO_CHAN_INFO_SAMP_FREQ: 245 *val = stk8ba50_samp_freq_table 246 [data->sample_rate_idx].samp_freq; 247 *val2 = 0; 248 return IIO_VAL_INT; 249 } 250 251 return -EINVAL; 252 } 253 254 static int stk8ba50_write_raw(struct iio_dev *indio_dev, 255 struct iio_chan_spec const *chan, 256 int val, int val2, long mask) 257 { 258 int ret; 259 int i; 260 int index = -1; 261 struct stk8ba50_data *data = iio_priv(indio_dev); 262 263 switch (mask) { 264 case IIO_CHAN_INFO_SCALE: 265 if (val != 0) 266 return -EINVAL; 267 268 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++) 269 if (val2 == stk8ba50_scale_table[i].scale_val) { 270 index = i; 271 break; 272 } 273 if (index < 0) 274 return -EINVAL; 275 276 ret = i2c_smbus_write_byte_data(data->client, 277 STK8BA50_REG_RANGE, 278 stk8ba50_scale_table[index].reg_val); 279 if (ret < 0) 280 dev_err(&data->client->dev, 281 "failed to set measurement range\n"); 282 else 283 data->range = index; 284 285 return ret; 286 case IIO_CHAN_INFO_SAMP_FREQ: 287 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++) 288 if (val == stk8ba50_samp_freq_table[i].samp_freq) { 289 index = i; 290 break; 291 } 292 if (index < 0) 293 return -EINVAL; 294 295 ret = i2c_smbus_write_byte_data(data->client, 296 STK8BA50_REG_BWSEL, 297 stk8ba50_samp_freq_table[index].reg_val); 298 if (ret < 0) 299 dev_err(&data->client->dev, 300 "failed to set sampling rate\n"); 301 else 302 data->sample_rate_idx = index; 303 304 return ret; 305 } 306 307 return -EINVAL; 308 } 309 310 static const struct iio_info stk8ba50_info = { 311 .driver_module = THIS_MODULE, 312 .read_raw = stk8ba50_read_raw, 313 .write_raw = stk8ba50_write_raw, 314 .attrs = &stk8ba50_attribute_group, 315 }; 316 317 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p) 318 { 319 struct iio_poll_func *pf = p; 320 struct iio_dev *indio_dev = pf->indio_dev; 321 struct stk8ba50_data *data = iio_priv(indio_dev); 322 int bit, ret, i = 0; 323 324 mutex_lock(&data->lock); 325 /* 326 * Do a bulk read if all channels are requested, 327 * from 0x02 (XOUT1) to 0x07 (ZOUT2) 328 */ 329 if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) { 330 ret = i2c_smbus_read_i2c_block_data(data->client, 331 STK8BA50_REG_XOUT, 332 STK8BA50_ALL_CHANNEL_SIZE, 333 (u8 *)data->buffer); 334 if (ret < STK8BA50_ALL_CHANNEL_SIZE) { 335 dev_err(&data->client->dev, "register read failed\n"); 336 goto err; 337 } 338 } else { 339 for_each_set_bit(bit, indio_dev->active_scan_mask, 340 indio_dev->masklength) { 341 ret = stk8ba50_read_accel(data, 342 stk8ba50_channel_table[bit]); 343 if (ret < 0) 344 goto err; 345 346 data->buffer[i++] = ret; 347 } 348 } 349 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 350 pf->timestamp); 351 err: 352 mutex_unlock(&data->lock); 353 iio_trigger_notify_done(indio_dev->trig); 354 355 return IRQ_HANDLED; 356 } 357 358 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private) 359 { 360 struct iio_dev *indio_dev = private; 361 struct stk8ba50_data *data = iio_priv(indio_dev); 362 363 if (data->dready_trigger_on) 364 iio_trigger_poll(data->dready_trig); 365 366 return IRQ_HANDLED; 367 } 368 369 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev) 370 { 371 struct stk8ba50_data *data = iio_priv(indio_dev); 372 373 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 374 } 375 376 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev) 377 { 378 struct stk8ba50_data *data = iio_priv(indio_dev); 379 380 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 381 } 382 383 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = { 384 .preenable = stk8ba50_buffer_preenable, 385 .postenable = iio_triggered_buffer_postenable, 386 .predisable = iio_triggered_buffer_predisable, 387 .postdisable = stk8ba50_buffer_postdisable, 388 }; 389 390 static int stk8ba50_probe(struct i2c_client *client, 391 const struct i2c_device_id *id) 392 { 393 int ret; 394 struct iio_dev *indio_dev; 395 struct stk8ba50_data *data; 396 397 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 398 if (!indio_dev) { 399 dev_err(&client->dev, "iio allocation failed!\n"); 400 return -ENOMEM; 401 } 402 403 data = iio_priv(indio_dev); 404 data->client = client; 405 i2c_set_clientdata(client, indio_dev); 406 mutex_init(&data->lock); 407 408 indio_dev->dev.parent = &client->dev; 409 indio_dev->info = &stk8ba50_info; 410 indio_dev->name = STK8BA50_DRIVER_NAME; 411 indio_dev->modes = INDIO_DIRECT_MODE; 412 indio_dev->channels = stk8ba50_channels; 413 indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels); 414 415 /* Reset all registers on startup */ 416 ret = i2c_smbus_write_byte_data(client, 417 STK8BA50_REG_SWRST, STK8BA50_RESET_CMD); 418 if (ret < 0) { 419 dev_err(&client->dev, "failed to reset sensor\n"); 420 goto err_power_off; 421 } 422 423 /* The default range is +/-2g */ 424 data->range = 0; 425 426 /* The default sampling rate is 1792 Hz (maximum) */ 427 data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX; 428 429 /* Set up interrupts */ 430 ret = i2c_smbus_write_byte_data(client, 431 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK); 432 if (ret < 0) { 433 dev_err(&client->dev, "failed to set up interrupts\n"); 434 goto err_power_off; 435 } 436 ret = i2c_smbus_write_byte_data(client, 437 STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP); 438 if (ret < 0) { 439 dev_err(&client->dev, "failed to set up interrupts\n"); 440 goto err_power_off; 441 } 442 443 if (client->irq > 0) { 444 ret = devm_request_threaded_irq(&client->dev, client->irq, 445 stk8ba50_data_rdy_trig_poll, 446 NULL, 447 IRQF_TRIGGER_RISING | 448 IRQF_ONESHOT, 449 STK8BA50_IRQ_NAME, 450 indio_dev); 451 if (ret < 0) { 452 dev_err(&client->dev, "request irq %d failed\n", 453 client->irq); 454 goto err_power_off; 455 } 456 457 data->dready_trig = devm_iio_trigger_alloc(&client->dev, 458 "%s-dev%d", 459 indio_dev->name, 460 indio_dev->id); 461 if (!data->dready_trig) { 462 ret = -ENOMEM; 463 goto err_power_off; 464 } 465 466 data->dready_trig->dev.parent = &client->dev; 467 data->dready_trig->ops = &stk8ba50_trigger_ops; 468 iio_trigger_set_drvdata(data->dready_trig, indio_dev); 469 ret = iio_trigger_register(data->dready_trig); 470 if (ret) { 471 dev_err(&client->dev, "iio trigger register failed\n"); 472 goto err_power_off; 473 } 474 } 475 476 ret = iio_triggered_buffer_setup(indio_dev, 477 iio_pollfunc_store_time, 478 stk8ba50_trigger_handler, 479 &stk8ba50_buffer_setup_ops); 480 if (ret < 0) { 481 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 482 goto err_trigger_unregister; 483 } 484 485 ret = iio_device_register(indio_dev); 486 if (ret < 0) { 487 dev_err(&client->dev, "device_register failed\n"); 488 goto err_buffer_cleanup; 489 } 490 491 return ret; 492 493 err_buffer_cleanup: 494 iio_triggered_buffer_cleanup(indio_dev); 495 err_trigger_unregister: 496 if (data->dready_trig) 497 iio_trigger_unregister(data->dready_trig); 498 err_power_off: 499 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 500 return ret; 501 } 502 503 static int stk8ba50_remove(struct i2c_client *client) 504 { 505 struct iio_dev *indio_dev = i2c_get_clientdata(client); 506 struct stk8ba50_data *data = iio_priv(indio_dev); 507 508 iio_device_unregister(indio_dev); 509 iio_triggered_buffer_cleanup(indio_dev); 510 511 if (data->dready_trig) 512 iio_trigger_unregister(data->dready_trig); 513 514 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 515 } 516 517 #ifdef CONFIG_PM_SLEEP 518 static int stk8ba50_suspend(struct device *dev) 519 { 520 struct stk8ba50_data *data; 521 522 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 523 524 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND); 525 } 526 527 static int stk8ba50_resume(struct device *dev) 528 { 529 struct stk8ba50_data *data; 530 531 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 532 533 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL); 534 } 535 536 static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume); 537 538 #define STK8BA50_PM_OPS (&stk8ba50_pm_ops) 539 #else 540 #define STK8BA50_PM_OPS NULL 541 #endif 542 543 static const struct i2c_device_id stk8ba50_i2c_id[] = { 544 {"stk8ba50", 0}, 545 {} 546 }; 547 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id); 548 549 static const struct acpi_device_id stk8ba50_acpi_id[] = { 550 {"STK8BA50", 0}, 551 {} 552 }; 553 554 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id); 555 556 static struct i2c_driver stk8ba50_driver = { 557 .driver = { 558 .name = "stk8ba50", 559 .pm = STK8BA50_PM_OPS, 560 .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id), 561 }, 562 .probe = stk8ba50_probe, 563 .remove = stk8ba50_remove, 564 .id_table = stk8ba50_i2c_id, 565 }; 566 567 module_i2c_driver(stk8ba50_driver); 568 569 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 570 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver"); 571 MODULE_LICENSE("GPL v2"); 572