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/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 STK8312_REG_XOUT 0x00 23 #define STK8312_REG_YOUT 0x01 24 #define STK8312_REG_ZOUT 0x02 25 #define STK8312_REG_INTSU 0x06 26 #define STK8312_REG_MODE 0x07 27 #define STK8312_REG_SR 0x08 28 #define STK8312_REG_STH 0x13 29 #define STK8312_REG_RESET 0x20 30 #define STK8312_REG_AFECTRL 0x24 31 #define STK8312_REG_OTPADDR 0x3D 32 #define STK8312_REG_OTPDATA 0x3E 33 #define STK8312_REG_OTPCTRL 0x3F 34 35 #define STK8312_MODE_ACTIVE BIT(0) 36 #define STK8312_MODE_STANDBY 0x00 37 #define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */ 38 #define STK8312_DREADY_BIT BIT(4) 39 #define STK8312_RNG_6G 1 40 #define STK8312_RNG_SHIFT 6 41 #define STK8312_RNG_MASK GENMASK(7, 6) 42 #define STK8312_SR_MASK GENMASK(2, 0) 43 #define STK8312_SR_400HZ_IDX 0 44 #define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0) 45 #define STK8312_ALL_CHANNEL_SIZE 3 46 47 #define STK8312_DRIVER_NAME "stk8312" 48 #define STK8312_IRQ_NAME "stk8312_event" 49 50 /* 51 * The accelerometer has two measurement ranges: 52 * 53 * -6g - +6g (8-bit, signed) 54 * -16g - +16g (8-bit, signed) 55 * 56 * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616 57 * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311 58 */ 59 #define STK8312_SCALE_AVAIL "0.4616 1.2311" 60 61 static const int stk8312_scale_table[][2] = { 62 {0, 461600}, {1, 231100} 63 }; 64 65 static const struct { 66 int val; 67 int val2; 68 } stk8312_samp_freq_table[] = { 69 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0}, 70 {12, 500000}, {6, 250000}, {3, 125000} 71 }; 72 73 #define STK8312_ACCEL_CHANNEL(index, reg, axis) { \ 74 .type = IIO_ACCEL, \ 75 .address = reg, \ 76 .modified = 1, \ 77 .channel2 = IIO_MOD_##axis, \ 78 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 79 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 80 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 81 .scan_index = index, \ 82 .scan_type = { \ 83 .sign = 's', \ 84 .realbits = 8, \ 85 .storagebits = 8, \ 86 .endianness = IIO_CPU, \ 87 }, \ 88 } 89 90 static const struct iio_chan_spec stk8312_channels[] = { 91 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X), 92 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y), 93 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z), 94 IIO_CHAN_SOFT_TIMESTAMP(3), 95 }; 96 97 struct stk8312_data { 98 struct i2c_client *client; 99 struct mutex lock; 100 u8 range; 101 u8 sample_rate_idx; 102 u8 mode; 103 struct iio_trigger *dready_trig; 104 bool dready_trigger_on; 105 /* Ensure timestamp is naturally aligned */ 106 struct { 107 s8 chans[3]; 108 s64 timestamp __aligned(8); 109 } scan; 110 }; 111 112 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL); 113 114 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400"); 115 116 static struct attribute *stk8312_attributes[] = { 117 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 118 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 119 NULL, 120 }; 121 122 static const struct attribute_group stk8312_attribute_group = { 123 .attrs = stk8312_attributes 124 }; 125 126 static int stk8312_otp_init(struct stk8312_data *data) 127 { 128 int ret; 129 int count = 10; 130 struct i2c_client *client = data->client; 131 132 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70); 133 if (ret < 0) 134 goto exit_err; 135 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02); 136 if (ret < 0) 137 goto exit_err; 138 139 do { 140 usleep_range(1000, 5000); 141 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL); 142 if (ret < 0) 143 goto exit_err; 144 count--; 145 } while (!(ret & BIT(7)) && count > 0); 146 147 if (count == 0) { 148 ret = -ETIMEDOUT; 149 goto exit_err; 150 } 151 152 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA); 153 if (ret == 0) 154 ret = -EINVAL; 155 if (ret < 0) 156 goto exit_err; 157 158 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret); 159 if (ret < 0) 160 goto exit_err; 161 msleep(150); 162 163 return 0; 164 165 exit_err: 166 dev_err(&client->dev, "failed to initialize sensor\n"); 167 return ret; 168 } 169 170 static int stk8312_set_mode(struct stk8312_data *data, u8 mode) 171 { 172 int ret; 173 struct i2c_client *client = data->client; 174 175 if (mode == data->mode) 176 return 0; 177 178 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode); 179 if (ret < 0) { 180 dev_err(&client->dev, "failed to change sensor mode\n"); 181 return ret; 182 } 183 184 data->mode = mode; 185 if (mode & STK8312_MODE_ACTIVE) { 186 /* Need to run OTP sequence before entering active mode */ 187 usleep_range(1000, 5000); 188 ret = stk8312_otp_init(data); 189 } 190 191 return ret; 192 } 193 194 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask) 195 { 196 int ret; 197 u8 mode; 198 struct i2c_client *client = data->client; 199 200 mode = data->mode; 201 /* We need to go in standby mode to modify registers */ 202 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); 203 if (ret < 0) 204 return ret; 205 206 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask); 207 if (ret < 0) { 208 dev_err(&client->dev, "failed to set interrupts\n"); 209 stk8312_set_mode(data, mode); 210 return ret; 211 } 212 213 return stk8312_set_mode(data, mode); 214 } 215 216 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig, 217 bool state) 218 { 219 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); 220 struct stk8312_data *data = iio_priv(indio_dev); 221 int ret; 222 223 if (state) 224 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT); 225 else 226 ret = stk8312_set_interrupts(data, 0x00); 227 228 if (ret < 0) { 229 dev_err(&data->client->dev, "failed to set trigger state\n"); 230 return ret; 231 } 232 233 data->dready_trigger_on = state; 234 235 return 0; 236 } 237 238 static const struct iio_trigger_ops stk8312_trigger_ops = { 239 .set_trigger_state = stk8312_data_rdy_trigger_set_state, 240 }; 241 242 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate) 243 { 244 int ret; 245 u8 masked_reg; 246 u8 mode; 247 struct i2c_client *client = data->client; 248 249 if (rate == data->sample_rate_idx) 250 return 0; 251 252 mode = data->mode; 253 /* We need to go in standby mode to modify registers */ 254 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); 255 if (ret < 0) 256 return ret; 257 258 ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR); 259 if (ret < 0) 260 goto err_activate; 261 262 masked_reg = (ret & (~STK8312_SR_MASK)) | rate; 263 264 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg); 265 if (ret < 0) 266 goto err_activate; 267 268 data->sample_rate_idx = rate; 269 270 return stk8312_set_mode(data, mode); 271 272 err_activate: 273 dev_err(&client->dev, "failed to set sampling rate\n"); 274 stk8312_set_mode(data, mode); 275 276 return ret; 277 } 278 279 static int stk8312_set_range(struct stk8312_data *data, u8 range) 280 { 281 int ret; 282 u8 masked_reg; 283 u8 mode; 284 struct i2c_client *client = data->client; 285 286 if (range != 1 && range != 2) 287 return -EINVAL; 288 else if (range == data->range) 289 return 0; 290 291 mode = data->mode; 292 /* We need to go in standby mode to modify registers */ 293 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY); 294 if (ret < 0) 295 return ret; 296 297 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH); 298 if (ret < 0) 299 goto err_activate; 300 301 masked_reg = ret & (~STK8312_RNG_MASK); 302 masked_reg |= range << STK8312_RNG_SHIFT; 303 304 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg); 305 if (ret < 0) 306 goto err_activate; 307 308 data->range = range; 309 310 return stk8312_set_mode(data, mode); 311 312 err_activate: 313 dev_err(&client->dev, "failed to change sensor range\n"); 314 stk8312_set_mode(data, mode); 315 316 return ret; 317 } 318 319 static int stk8312_read_accel(struct stk8312_data *data, u8 address) 320 { 321 int ret; 322 struct i2c_client *client = data->client; 323 324 if (address > 2) 325 return -EINVAL; 326 327 ret = i2c_smbus_read_byte_data(client, address); 328 if (ret < 0) 329 dev_err(&client->dev, "register read failed\n"); 330 331 return ret; 332 } 333 334 static int stk8312_read_raw(struct iio_dev *indio_dev, 335 struct iio_chan_spec const *chan, 336 int *val, int *val2, long mask) 337 { 338 struct stk8312_data *data = iio_priv(indio_dev); 339 int ret; 340 341 switch (mask) { 342 case IIO_CHAN_INFO_RAW: 343 if (iio_buffer_enabled(indio_dev)) 344 return -EBUSY; 345 mutex_lock(&data->lock); 346 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 347 if (ret < 0) { 348 mutex_unlock(&data->lock); 349 return ret; 350 } 351 ret = stk8312_read_accel(data, chan->address); 352 if (ret < 0) { 353 stk8312_set_mode(data, 354 data->mode & (~STK8312_MODE_ACTIVE)); 355 mutex_unlock(&data->lock); 356 return ret; 357 } 358 *val = sign_extend32(ret, chan->scan_type.realbits - 1); 359 ret = stk8312_set_mode(data, 360 data->mode & (~STK8312_MODE_ACTIVE)); 361 mutex_unlock(&data->lock); 362 if (ret < 0) 363 return ret; 364 return IIO_VAL_INT; 365 case IIO_CHAN_INFO_SCALE: 366 *val = stk8312_scale_table[data->range - 1][0]; 367 *val2 = stk8312_scale_table[data->range - 1][1]; 368 return IIO_VAL_INT_PLUS_MICRO; 369 case IIO_CHAN_INFO_SAMP_FREQ: 370 *val = stk8312_samp_freq_table[data->sample_rate_idx].val; 371 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2; 372 return IIO_VAL_INT_PLUS_MICRO; 373 } 374 375 return -EINVAL; 376 } 377 378 static int stk8312_write_raw(struct iio_dev *indio_dev, 379 struct iio_chan_spec const *chan, 380 int val, int val2, long mask) 381 { 382 int i; 383 int index = -1; 384 int ret; 385 struct stk8312_data *data = iio_priv(indio_dev); 386 387 switch (mask) { 388 case IIO_CHAN_INFO_SCALE: 389 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++) 390 if (val == stk8312_scale_table[i][0] && 391 val2 == stk8312_scale_table[i][1]) { 392 index = i + 1; 393 break; 394 } 395 if (index < 0) 396 return -EINVAL; 397 398 mutex_lock(&data->lock); 399 ret = stk8312_set_range(data, index); 400 mutex_unlock(&data->lock); 401 402 return ret; 403 case IIO_CHAN_INFO_SAMP_FREQ: 404 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++) 405 if (val == stk8312_samp_freq_table[i].val && 406 val2 == stk8312_samp_freq_table[i].val2) { 407 index = i; 408 break; 409 } 410 if (index < 0) 411 return -EINVAL; 412 mutex_lock(&data->lock); 413 ret = stk8312_set_sample_rate(data, index); 414 mutex_unlock(&data->lock); 415 416 return ret; 417 } 418 419 return -EINVAL; 420 } 421 422 static const struct iio_info stk8312_info = { 423 .read_raw = stk8312_read_raw, 424 .write_raw = stk8312_write_raw, 425 .attrs = &stk8312_attribute_group, 426 }; 427 428 static irqreturn_t stk8312_trigger_handler(int irq, void *p) 429 { 430 struct iio_poll_func *pf = p; 431 struct iio_dev *indio_dev = pf->indio_dev; 432 struct stk8312_data *data = iio_priv(indio_dev); 433 int bit, ret, i = 0; 434 435 mutex_lock(&data->lock); 436 /* 437 * Do a bulk read if all channels are requested, 438 * from 0x00 (XOUT) to 0x02 (ZOUT) 439 */ 440 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) { 441 ret = i2c_smbus_read_i2c_block_data(data->client, 442 STK8312_REG_XOUT, 443 STK8312_ALL_CHANNEL_SIZE, 444 data->scan.chans); 445 if (ret < STK8312_ALL_CHANNEL_SIZE) { 446 dev_err(&data->client->dev, "register read failed\n"); 447 mutex_unlock(&data->lock); 448 goto err; 449 } 450 } else { 451 for_each_set_bit(bit, indio_dev->active_scan_mask, 452 indio_dev->masklength) { 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", 0 }, 637 { "stk8312", 0 }, 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_new = 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