1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Sensortek STK8312 3-Axis Accelerometer 4 * 5 * Copyright (c) 2015, Intel Corporation. 6 * 7 * IIO driver for STK8312; 7-bit I2C address: 0x3D. 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/delay.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 STK8312_REG_XOUT 0x00 24 #define STK8312_REG_YOUT 0x01 25 #define STK8312_REG_ZOUT 0x02 26 #define STK8312_REG_INTSU 0x06 27 #define STK8312_REG_MODE 0x07 28 #define STK8312_REG_SR 0x08 29 #define STK8312_REG_STH 0x13 30 #define STK8312_REG_RESET 0x20 31 #define STK8312_REG_AFECTRL 0x24 32 #define STK8312_REG_OTPADDR 0x3D 33 #define STK8312_REG_OTPDATA 0x3E 34 #define STK8312_REG_OTPCTRL 0x3F 35 36 #define STK8312_MODE_ACTIVE BIT(0) 37 #define STK8312_MODE_STANDBY 0x00 38 #define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */ 39 #define STK8312_DREADY_BIT BIT(4) 40 #define STK8312_RNG_6G 1 41 #define STK8312_RNG_SHIFT 6 42 #define STK8312_RNG_MASK GENMASK(7, 6) 43 #define STK8312_SR_MASK GENMASK(2, 0) 44 #define STK8312_SR_400HZ_IDX 0 45 #define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0) 46 #define STK8312_ALL_CHANNEL_SIZE 3 47 48 #define STK8312_DRIVER_NAME "stk8312" 49 #define STK8312_IRQ_NAME "stk8312_event" 50 51 /* 52 * The accelerometer has two measurement ranges: 53 * 54 * -6g - +6g (8-bit, signed) 55 * -16g - +16g (8-bit, signed) 56 * 57 * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616 58 * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311 59 */ 60 #define STK8312_SCALE_AVAIL "0.4616 1.2311" 61 62 static const int stk8312_scale_table[][2] = { 63 {0, 461600}, {1, 231100} 64 }; 65 66 static const struct { 67 int val; 68 int val2; 69 } stk8312_samp_freq_table[] = { 70 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0}, 71 {12, 500000}, {6, 250000}, {3, 125000} 72 }; 73 74 #define STK8312_ACCEL_CHANNEL(index, reg, axis) { \ 75 .type = IIO_ACCEL, \ 76 .address = reg, \ 77 .modified = 1, \ 78 .channel2 = IIO_MOD_##axis, \ 79 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 80 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 81 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 82 .scan_index = index, \ 83 .scan_type = { \ 84 .sign = 's', \ 85 .realbits = 8, \ 86 .storagebits = 8, \ 87 .endianness = IIO_CPU, \ 88 }, \ 89 } 90 91 static const struct iio_chan_spec stk8312_channels[] = { 92 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X), 93 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y), 94 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z), 95 IIO_CHAN_SOFT_TIMESTAMP(3), 96 }; 97 98 struct stk8312_data { 99 struct i2c_client *client; 100 struct mutex lock; 101 u8 range; 102 u8 sample_rate_idx; 103 u8 mode; 104 struct iio_trigger *dready_trig; 105 bool dready_trigger_on; 106 /* Ensure timestamp is naturally aligned */ 107 struct { 108 s8 chans[3]; 109 aligned_s64 timestamp; 110 } scan; 111 }; 112 113 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL); 114 115 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400"); 116 117 static struct attribute *stk8312_attributes[] = { 118 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 119 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 120 NULL, 121 }; 122 123 static const struct attribute_group stk8312_attribute_group = { 124 .attrs = stk8312_attributes 125 }; 126 127 static int stk8312_otp_init(struct stk8312_data *data) 128 { 129 int ret; 130 int count = 10; 131 struct i2c_client *client = data->client; 132 133 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70); 134 if (ret < 0) 135 goto exit_err; 136 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02); 137 if (ret < 0) 138 goto exit_err; 139 140 do { 141 usleep_range(1000, 5000); 142 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL); 143 if (ret < 0) 144 goto exit_err; 145 count--; 146 } while (!(ret & BIT(7)) && count > 0); 147 148 if (count == 0) { 149 ret = -ETIMEDOUT; 150 goto exit_err; 151 } 152 153 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA); 154 if (ret == 0) 155 ret = -EINVAL; 156 if (ret < 0) 157 goto exit_err; 158 159 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret); 160 if (ret < 0) 161 goto exit_err; 162 msleep(150); 163 164 return 0; 165 166 exit_err: 167 dev_err(&client->dev, "failed to initialize sensor\n"); 168 return ret; 169 } 170 171 static int stk8312_set_mode(struct stk8312_data *data, u8 mode) 172 { 173 int ret; 174 struct i2c_client *client = data->client; 175 176 if (mode == data->mode) 177 return 0; 178 179 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode); 180 if (ret < 0) { 181 dev_err(&client->dev, "failed to change sensor mode\n"); 182 return ret; 183 } 184 185 data->mode = mode; 186 if (mode & STK8312_MODE_ACTIVE) { 187 /* Need to run OTP sequence before entering active mode */ 188 usleep_range(1000, 5000); 189 ret = stk8312_otp_init(data); 190 } 191 192 return ret; 193 } 194 195 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask) 196 { 197 int ret; 198 u8 mode; 199 struct i2c_client *client = data->client; 200 201 mode = data->mode; 202 /* We need to go in standby mode to modify registers */ 203 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); 204 if (ret < 0) 205 return ret; 206 207 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask); 208 if (ret < 0) { 209 dev_err(&client->dev, "failed to set interrupts\n"); 210 stk8312_set_mode(data, mode); 211 return ret; 212 } 213 214 return stk8312_set_mode(data, mode); 215 } 216 217 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig, 218 bool state) 219 { 220 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 221 struct stk8312_data *data = iio_priv(indio_dev); 222 int ret; 223 224 if (state) 225 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT); 226 else 227 ret = stk8312_set_interrupts(data, 0x00); 228 229 if (ret < 0) { 230 dev_err(&data->client->dev, "failed to set trigger state\n"); 231 return ret; 232 } 233 234 data->dready_trigger_on = state; 235 236 return 0; 237 } 238 239 static const struct iio_trigger_ops stk8312_trigger_ops = { 240 .set_trigger_state = stk8312_data_rdy_trigger_set_state, 241 }; 242 243 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate) 244 { 245 int ret; 246 u8 masked_reg; 247 u8 mode; 248 struct i2c_client *client = data->client; 249 250 if (rate == data->sample_rate_idx) 251 return 0; 252 253 mode = data->mode; 254 /* We need to go in standby mode to modify registers */ 255 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); 256 if (ret < 0) 257 return ret; 258 259 ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR); 260 if (ret < 0) 261 goto err_activate; 262 263 masked_reg = (ret & (~STK8312_SR_MASK)) | rate; 264 265 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg); 266 if (ret < 0) 267 goto err_activate; 268 269 data->sample_rate_idx = rate; 270 271 return stk8312_set_mode(data, mode); 272 273 err_activate: 274 dev_err(&client->dev, "failed to set sampling rate\n"); 275 stk8312_set_mode(data, mode); 276 277 return ret; 278 } 279 280 static int stk8312_set_range(struct stk8312_data *data, u8 range) 281 { 282 int ret; 283 u8 masked_reg; 284 u8 mode; 285 struct i2c_client *client = data->client; 286 287 if (range != 1 && range != 2) 288 return -EINVAL; 289 else if (range == data->range) 290 return 0; 291 292 mode = data->mode; 293 /* We need to go in standby mode to modify registers */ 294 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); 295 if (ret < 0) 296 return ret; 297 298 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH); 299 if (ret < 0) 300 goto err_activate; 301 302 masked_reg = ret & (~STK8312_RNG_MASK); 303 masked_reg |= range << STK8312_RNG_SHIFT; 304 305 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg); 306 if (ret < 0) 307 goto err_activate; 308 309 data->range = range; 310 311 return stk8312_set_mode(data, mode); 312 313 err_activate: 314 dev_err(&client->dev, "failed to change sensor range\n"); 315 stk8312_set_mode(data, mode); 316 317 return ret; 318 } 319 320 static int stk8312_read_accel(struct stk8312_data *data, u8 address) 321 { 322 int ret; 323 struct i2c_client *client = data->client; 324 325 if (address > 2) 326 return -EINVAL; 327 328 ret = i2c_smbus_read_byte_data(client, address); 329 if (ret < 0) 330 dev_err(&client->dev, "register read failed\n"); 331 332 return ret; 333 } 334 335 static int stk8312_read_raw(struct iio_dev *indio_dev, 336 struct iio_chan_spec const *chan, 337 int *val, int *val2, long mask) 338 { 339 struct stk8312_data *data = iio_priv(indio_dev); 340 int ret; 341 342 switch (mask) { 343 case IIO_CHAN_INFO_RAW: 344 if (iio_buffer_enabled(indio_dev)) 345 return -EBUSY; 346 mutex_lock(&data->lock); 347 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 348 if (ret < 0) { 349 mutex_unlock(&data->lock); 350 return ret; 351 } 352 ret = stk8312_read_accel(data, chan->address); 353 if (ret < 0) { 354 stk8312_set_mode(data, 355 data->mode & (~STK8312_MODE_ACTIVE)); 356 mutex_unlock(&data->lock); 357 return ret; 358 } 359 *val = sign_extend32(ret, chan->scan_type.realbits - 1); 360 ret = stk8312_set_mode(data, 361 data->mode & (~STK8312_MODE_ACTIVE)); 362 mutex_unlock(&data->lock); 363 if (ret < 0) 364 return ret; 365 return IIO_VAL_INT; 366 case IIO_CHAN_INFO_SCALE: 367 *val = stk8312_scale_table[data->range - 1][0]; 368 *val2 = stk8312_scale_table[data->range - 1][1]; 369 return IIO_VAL_INT_PLUS_MICRO; 370 case IIO_CHAN_INFO_SAMP_FREQ: 371 *val = stk8312_samp_freq_table[data->sample_rate_idx].val; 372 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2; 373 return IIO_VAL_INT_PLUS_MICRO; 374 } 375 376 return -EINVAL; 377 } 378 379 static int stk8312_write_raw(struct iio_dev *indio_dev, 380 struct iio_chan_spec const *chan, 381 int val, int val2, long mask) 382 { 383 int i; 384 int index = -1; 385 int ret; 386 struct stk8312_data *data = iio_priv(indio_dev); 387 388 switch (mask) { 389 case IIO_CHAN_INFO_SCALE: 390 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++) 391 if (val == stk8312_scale_table[i][0] && 392 val2 == stk8312_scale_table[i][1]) { 393 index = i + 1; 394 break; 395 } 396 if (index < 0) 397 return -EINVAL; 398 399 mutex_lock(&data->lock); 400 ret = stk8312_set_range(data, index); 401 mutex_unlock(&data->lock); 402 403 return ret; 404 case IIO_CHAN_INFO_SAMP_FREQ: 405 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++) 406 if (val == stk8312_samp_freq_table[i].val && 407 val2 == stk8312_samp_freq_table[i].val2) { 408 index = i; 409 break; 410 } 411 if (index < 0) 412 return -EINVAL; 413 mutex_lock(&data->lock); 414 ret = stk8312_set_sample_rate(data, index); 415 mutex_unlock(&data->lock); 416 417 return ret; 418 } 419 420 return -EINVAL; 421 } 422 423 static const struct iio_info stk8312_info = { 424 .read_raw = stk8312_read_raw, 425 .write_raw = stk8312_write_raw, 426 .attrs = &stk8312_attribute_group, 427 }; 428 429 static irqreturn_t stk8312_trigger_handler(int irq, void *p) 430 { 431 struct iio_poll_func *pf = p; 432 struct iio_dev *indio_dev = pf->indio_dev; 433 struct stk8312_data *data = iio_priv(indio_dev); 434 int bit, ret, i = 0; 435 436 mutex_lock(&data->lock); 437 /* 438 * Do a bulk read if all channels are requested, 439 * from 0x00 (XOUT) to 0x02 (ZOUT) 440 */ 441 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) { 442 ret = i2c_smbus_read_i2c_block_data(data->client, 443 STK8312_REG_XOUT, 444 STK8312_ALL_CHANNEL_SIZE, 445 data->scan.chans); 446 if (ret < STK8312_ALL_CHANNEL_SIZE) { 447 dev_err(&data->client->dev, "register read failed\n"); 448 mutex_unlock(&data->lock); 449 goto err; 450 } 451 } else { 452 iio_for_each_active_channel(indio_dev, bit) { 453 ret = stk8312_read_accel(data, bit); 454 if (ret < 0) { 455 mutex_unlock(&data->lock); 456 goto err; 457 } 458 data->scan.chans[i++] = ret; 459 } 460 } 461 mutex_unlock(&data->lock); 462 463 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 464 pf->timestamp); 465 err: 466 iio_trigger_notify_done(indio_dev->trig); 467 468 return IRQ_HANDLED; 469 } 470 471 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private) 472 { 473 struct iio_dev *indio_dev = private; 474 struct stk8312_data *data = iio_priv(indio_dev); 475 476 if (data->dready_trigger_on) 477 iio_trigger_poll(data->dready_trig); 478 479 return IRQ_HANDLED; 480 } 481 482 static int stk8312_buffer_preenable(struct iio_dev *indio_dev) 483 { 484 struct stk8312_data *data = iio_priv(indio_dev); 485 486 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 487 } 488 489 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev) 490 { 491 struct stk8312_data *data = iio_priv(indio_dev); 492 493 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); 494 } 495 496 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = { 497 .preenable = stk8312_buffer_preenable, 498 .postdisable = stk8312_buffer_postdisable, 499 }; 500 501 static int stk8312_probe(struct i2c_client *client) 502 { 503 int ret; 504 struct iio_dev *indio_dev; 505 struct stk8312_data *data; 506 507 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 508 if (!indio_dev) { 509 dev_err(&client->dev, "iio allocation failed!\n"); 510 return -ENOMEM; 511 } 512 513 data = iio_priv(indio_dev); 514 data->client = client; 515 i2c_set_clientdata(client, indio_dev); 516 mutex_init(&data->lock); 517 518 indio_dev->info = &stk8312_info; 519 indio_dev->name = STK8312_DRIVER_NAME; 520 indio_dev->modes = INDIO_DIRECT_MODE; 521 indio_dev->channels = stk8312_channels; 522 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels); 523 524 /* A software reset is recommended at power-on */ 525 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00); 526 if (ret < 0) { 527 dev_err(&client->dev, "failed to reset sensor\n"); 528 return ret; 529 } 530 data->sample_rate_idx = STK8312_SR_400HZ_IDX; 531 ret = stk8312_set_range(data, STK8312_RNG_6G); 532 if (ret < 0) 533 return ret; 534 535 ret = stk8312_set_mode(data, 536 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE); 537 if (ret < 0) 538 return ret; 539 540 if (client->irq > 0) { 541 ret = devm_request_threaded_irq(&client->dev, client->irq, 542 stk8312_data_rdy_trig_poll, 543 NULL, 544 IRQF_TRIGGER_RISING | 545 IRQF_ONESHOT, 546 STK8312_IRQ_NAME, 547 indio_dev); 548 if (ret < 0) { 549 dev_err(&client->dev, "request irq %d failed\n", 550 client->irq); 551 goto err_power_off; 552 } 553 554 data->dready_trig = devm_iio_trigger_alloc(&client->dev, 555 "%s-dev%d", 556 indio_dev->name, 557 iio_device_id(indio_dev)); 558 if (!data->dready_trig) { 559 ret = -ENOMEM; 560 goto err_power_off; 561 } 562 563 data->dready_trig->ops = &stk8312_trigger_ops; 564 iio_trigger_set_drvdata(data->dready_trig, indio_dev); 565 ret = iio_trigger_register(data->dready_trig); 566 if (ret) { 567 dev_err(&client->dev, "iio trigger register failed\n"); 568 goto err_power_off; 569 } 570 } 571 572 ret = iio_triggered_buffer_setup(indio_dev, 573 iio_pollfunc_store_time, 574 stk8312_trigger_handler, 575 &stk8312_buffer_setup_ops); 576 if (ret < 0) { 577 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 578 goto err_trigger_unregister; 579 } 580 581 ret = iio_device_register(indio_dev); 582 if (ret < 0) { 583 dev_err(&client->dev, "device_register failed\n"); 584 goto err_buffer_cleanup; 585 } 586 587 return 0; 588 589 err_buffer_cleanup: 590 iio_triggered_buffer_cleanup(indio_dev); 591 err_trigger_unregister: 592 if (data->dready_trig) 593 iio_trigger_unregister(data->dready_trig); 594 err_power_off: 595 stk8312_set_mode(data, STK8312_MODE_STANDBY); 596 return ret; 597 } 598 599 static void stk8312_remove(struct i2c_client *client) 600 { 601 struct iio_dev *indio_dev = i2c_get_clientdata(client); 602 struct stk8312_data *data = iio_priv(indio_dev); 603 604 iio_device_unregister(indio_dev); 605 iio_triggered_buffer_cleanup(indio_dev); 606 607 if (data->dready_trig) 608 iio_trigger_unregister(data->dready_trig); 609 610 stk8312_set_mode(data, STK8312_MODE_STANDBY); 611 } 612 613 static int stk8312_suspend(struct device *dev) 614 { 615 struct stk8312_data *data; 616 617 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 618 619 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); 620 } 621 622 static int stk8312_resume(struct device *dev) 623 { 624 struct stk8312_data *data; 625 626 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 627 628 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 629 } 630 631 static DEFINE_SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, 632 stk8312_resume); 633 634 static const struct i2c_device_id stk8312_i2c_id[] = { 635 /* Deprecated in favour of lowercase form */ 636 { "STK8312" }, 637 { "stk8312" }, 638 {} 639 }; 640 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id); 641 642 static struct i2c_driver stk8312_driver = { 643 .driver = { 644 .name = STK8312_DRIVER_NAME, 645 .pm = pm_sleep_ptr(&stk8312_pm_ops), 646 }, 647 .probe = stk8312_probe, 648 .remove = stk8312_remove, 649 .id_table = stk8312_i2c_id, 650 }; 651 652 module_i2c_driver(stk8312_driver); 653 654 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 655 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver"); 656 MODULE_LICENSE("GPL v2"); 657