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/acpi.h> 11#include <linux/i2c.h> 12#include <linux/interrupt.h> 13#include <linux/kernel.h> 14#include <linux/module.h> 15#include <linux/delay.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 62static const int stk8312_scale_table[][2] = { 63 {0, 461600}, {1, 231100} 64}; 65 66static 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 91static 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 98struct 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 s64 timestamp __aligned(8); 110 } scan; 111}; 112 113static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL); 114 115static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400"); 116 117static 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 123static const struct attribute_group stk8312_attribute_group = { 124 .attrs = stk8312_attributes 125}; 126 127static 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 166exit_err: 167 dev_err(&client->dev, "failed to initialize sensor\n"); 168 return ret; 169} 170 171static 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 195static 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 217static 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 239static const struct iio_trigger_ops stk8312_trigger_ops = { 240 .set_trigger_state = stk8312_data_rdy_trigger_set_state, 241}; 242 243static 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 273err_activate: 274 dev_err(&client->dev, "failed to set sampling rate\n"); 275 stk8312_set_mode(data, mode); 276 277 return ret; 278} 279 280static 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 313err_activate: 314 dev_err(&client->dev, "failed to change sensor range\n"); 315 stk8312_set_mode(data, mode); 316 317 return ret; 318} 319 320static 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 335static 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, 7); 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 379static 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 423static 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 429static 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 for_each_set_bit(bit, indio_dev->active_scan_mask, 453 indio_dev->masklength) { 454 ret = stk8312_read_accel(data, bit); 455 if (ret < 0) { 456 mutex_unlock(&data->lock); 457 goto err; 458 } 459 data->scan.chans[i++] = ret; 460 } 461 } 462 mutex_unlock(&data->lock); 463 464 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, 465 pf->timestamp); 466err: 467 iio_trigger_notify_done(indio_dev->trig); 468 469 return IRQ_HANDLED; 470} 471 472static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private) 473{ 474 struct iio_dev *indio_dev = private; 475 struct stk8312_data *data = iio_priv(indio_dev); 476 477 if (data->dready_trigger_on) 478 iio_trigger_poll(data->dready_trig); 479 480 return IRQ_HANDLED; 481} 482 483static int stk8312_buffer_preenable(struct iio_dev *indio_dev) 484{ 485 struct stk8312_data *data = iio_priv(indio_dev); 486 487 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 488} 489 490static int stk8312_buffer_postdisable(struct iio_dev *indio_dev) 491{ 492 struct stk8312_data *data = iio_priv(indio_dev); 493 494 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); 495} 496 497static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = { 498 .preenable = stk8312_buffer_preenable, 499 .postdisable = stk8312_buffer_postdisable, 500}; 501 502static int stk8312_probe(struct i2c_client *client, 503 const struct i2c_device_id *id) 504{ 505 int ret; 506 struct iio_dev *indio_dev; 507 struct stk8312_data *data; 508 509 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 510 if (!indio_dev) { 511 dev_err(&client->dev, "iio allocation failed!\n"); 512 return -ENOMEM; 513 } 514 515 data = iio_priv(indio_dev); 516 data->client = client; 517 i2c_set_clientdata(client, indio_dev); 518 mutex_init(&data->lock); 519 520 indio_dev->info = &stk8312_info; 521 indio_dev->name = STK8312_DRIVER_NAME; 522 indio_dev->modes = INDIO_DIRECT_MODE; 523 indio_dev->channels = stk8312_channels; 524 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels); 525 526 /* A software reset is recommended at power-on */ 527 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00); 528 if (ret < 0) { 529 dev_err(&client->dev, "failed to reset sensor\n"); 530 return ret; 531 } 532 data->sample_rate_idx = STK8312_SR_400HZ_IDX; 533 ret = stk8312_set_range(data, STK8312_RNG_6G); 534 if (ret < 0) 535 return ret; 536 537 ret = stk8312_set_mode(data, 538 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE); 539 if (ret < 0) 540 return ret; 541 542 if (client->irq > 0) { 543 ret = devm_request_threaded_irq(&client->dev, client->irq, 544 stk8312_data_rdy_trig_poll, 545 NULL, 546 IRQF_TRIGGER_RISING | 547 IRQF_ONESHOT, 548 STK8312_IRQ_NAME, 549 indio_dev); 550 if (ret < 0) { 551 dev_err(&client->dev, "request irq %d failed\n", 552 client->irq); 553 goto err_power_off; 554 } 555 556 data->dready_trig = devm_iio_trigger_alloc(&client->dev, 557 "%s-dev%d", 558 indio_dev->name, 559 indio_dev->id); 560 if (!data->dready_trig) { 561 ret = -ENOMEM; 562 goto err_power_off; 563 } 564 565 data->dready_trig->dev.parent = &client->dev; 566 data->dready_trig->ops = &stk8312_trigger_ops; 567 iio_trigger_set_drvdata(data->dready_trig, indio_dev); 568 ret = iio_trigger_register(data->dready_trig); 569 if (ret) { 570 dev_err(&client->dev, "iio trigger register failed\n"); 571 goto err_power_off; 572 } 573 } 574 575 ret = iio_triggered_buffer_setup(indio_dev, 576 iio_pollfunc_store_time, 577 stk8312_trigger_handler, 578 &stk8312_buffer_setup_ops); 579 if (ret < 0) { 580 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 581 goto err_trigger_unregister; 582 } 583 584 ret = iio_device_register(indio_dev); 585 if (ret < 0) { 586 dev_err(&client->dev, "device_register failed\n"); 587 goto err_buffer_cleanup; 588 } 589 590 return 0; 591 592err_buffer_cleanup: 593 iio_triggered_buffer_cleanup(indio_dev); 594err_trigger_unregister: 595 if (data->dready_trig) 596 iio_trigger_unregister(data->dready_trig); 597err_power_off: 598 stk8312_set_mode(data, STK8312_MODE_STANDBY); 599 return ret; 600} 601 602static int stk8312_remove(struct i2c_client *client) 603{ 604 struct iio_dev *indio_dev = i2c_get_clientdata(client); 605 struct stk8312_data *data = iio_priv(indio_dev); 606 607 iio_device_unregister(indio_dev); 608 iio_triggered_buffer_cleanup(indio_dev); 609 610 if (data->dready_trig) 611 iio_trigger_unregister(data->dready_trig); 612 613 return stk8312_set_mode(data, STK8312_MODE_STANDBY); 614} 615 616#ifdef CONFIG_PM_SLEEP 617static int stk8312_suspend(struct device *dev) 618{ 619 struct stk8312_data *data; 620 621 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 622 623 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); 624} 625 626static int stk8312_resume(struct device *dev) 627{ 628 struct stk8312_data *data; 629 630 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 631 632 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 633} 634 635static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume); 636 637#define STK8312_PM_OPS (&stk8312_pm_ops) 638#else 639#define STK8312_PM_OPS NULL 640#endif 641 642static const struct i2c_device_id stk8312_i2c_id[] = { 643 {"STK8312", 0}, 644 {} 645}; 646MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id); 647 648static const struct acpi_device_id stk8312_acpi_id[] = { 649 {"STK8312", 0}, 650 {} 651}; 652 653MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id); 654 655static struct i2c_driver stk8312_driver = { 656 .driver = { 657 .name = STK8312_DRIVER_NAME, 658 .pm = STK8312_PM_OPS, 659 .acpi_match_table = ACPI_PTR(stk8312_acpi_id), 660 }, 661 .probe = stk8312_probe, 662 .remove = stk8312_remove, 663 .id_table = stk8312_i2c_id, 664}; 665 666module_i2c_driver(stk8312_driver); 667 668MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 669MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver"); 670MODULE_LICENSE("GPL v2"); 671