1 /** 2 * Sensortek STK8312 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 * IIO driver for STK8312; 7-bit I2C address: 0x3D. 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/delay.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 STK8312_REG_XOUT 0x00 27 #define STK8312_REG_YOUT 0x01 28 #define STK8312_REG_ZOUT 0x02 29 #define STK8312_REG_INTSU 0x06 30 #define STK8312_REG_MODE 0x07 31 #define STK8312_REG_SR 0x08 32 #define STK8312_REG_STH 0x13 33 #define STK8312_REG_RESET 0x20 34 #define STK8312_REG_AFECTRL 0x24 35 #define STK8312_REG_OTPADDR 0x3D 36 #define STK8312_REG_OTPDATA 0x3E 37 #define STK8312_REG_OTPCTRL 0x3F 38 39 #define STK8312_MODE_ACTIVE BIT(0) 40 #define STK8312_MODE_STANDBY 0x00 41 #define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */ 42 #define STK8312_DREADY_BIT BIT(4) 43 #define STK8312_RNG_6G 1 44 #define STK8312_RNG_SHIFT 6 45 #define STK8312_RNG_MASK GENMASK(7, 6) 46 #define STK8312_SR_MASK GENMASK(2, 0) 47 #define STK8312_SR_400HZ_IDX 0 48 #define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0) 49 #define STK8312_ALL_CHANNEL_SIZE 3 50 51 #define STK8312_DRIVER_NAME "stk8312" 52 #define STK8312_IRQ_NAME "stk8312_event" 53 54 /* 55 * The accelerometer has two measurement ranges: 56 * 57 * -6g - +6g (8-bit, signed) 58 * -16g - +16g (8-bit, signed) 59 * 60 * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616 61 * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311 62 */ 63 #define STK8312_SCALE_AVAIL "0.4616 1.2311" 64 65 static const int stk8312_scale_table[][2] = { 66 {0, 461600}, {1, 231100} 67 }; 68 69 static const struct { 70 int val; 71 int val2; 72 } stk8312_samp_freq_table[] = { 73 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0}, 74 {12, 500000}, {6, 250000}, {3, 125000} 75 }; 76 77 #define STK8312_ACCEL_CHANNEL(index, reg, axis) { \ 78 .type = IIO_ACCEL, \ 79 .address = reg, \ 80 .modified = 1, \ 81 .channel2 = IIO_MOD_##axis, \ 82 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 83 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 84 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 85 .scan_index = index, \ 86 .scan_type = { \ 87 .sign = 's', \ 88 .realbits = 8, \ 89 .storagebits = 8, \ 90 .endianness = IIO_CPU, \ 91 }, \ 92 } 93 94 static const struct iio_chan_spec stk8312_channels[] = { 95 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X), 96 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y), 97 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z), 98 IIO_CHAN_SOFT_TIMESTAMP(3), 99 }; 100 101 struct stk8312_data { 102 struct i2c_client *client; 103 struct mutex lock; 104 u8 range; 105 u8 sample_rate_idx; 106 u8 mode; 107 struct iio_trigger *dready_trig; 108 bool dready_trigger_on; 109 s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */ 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 .owner = THIS_MODULE, 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, 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 } 378 379 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 .driver_module = THIS_MODULE, 425 .read_raw = stk8312_read_raw, 426 .write_raw = stk8312_write_raw, 427 .attrs = &stk8312_attribute_group, 428 }; 429 430 static irqreturn_t stk8312_trigger_handler(int irq, void *p) 431 { 432 struct iio_poll_func *pf = p; 433 struct iio_dev *indio_dev = pf->indio_dev; 434 struct stk8312_data *data = iio_priv(indio_dev); 435 int bit, ret, i = 0; 436 437 mutex_lock(&data->lock); 438 /* 439 * Do a bulk read if all channels are requested, 440 * from 0x00 (XOUT) to 0x02 (ZOUT) 441 */ 442 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) { 443 ret = i2c_smbus_read_i2c_block_data(data->client, 444 STK8312_REG_XOUT, 445 STK8312_ALL_CHANNEL_SIZE, 446 data->buffer); 447 if (ret < STK8312_ALL_CHANNEL_SIZE) { 448 dev_err(&data->client->dev, "register read failed\n"); 449 mutex_unlock(&data->lock); 450 goto err; 451 } 452 } else { 453 for_each_set_bit(bit, indio_dev->active_scan_mask, 454 indio_dev->masklength) { 455 ret = stk8312_read_accel(data, bit); 456 if (ret < 0) { 457 mutex_unlock(&data->lock); 458 goto err; 459 } 460 data->buffer[i++] = ret; 461 } 462 } 463 mutex_unlock(&data->lock); 464 465 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, 466 pf->timestamp); 467 err: 468 iio_trigger_notify_done(indio_dev->trig); 469 470 return IRQ_HANDLED; 471 } 472 473 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private) 474 { 475 struct iio_dev *indio_dev = private; 476 struct stk8312_data *data = iio_priv(indio_dev); 477 478 if (data->dready_trigger_on) 479 iio_trigger_poll(data->dready_trig); 480 481 return IRQ_HANDLED; 482 } 483 484 static int stk8312_buffer_preenable(struct iio_dev *indio_dev) 485 { 486 struct stk8312_data *data = iio_priv(indio_dev); 487 488 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 489 } 490 491 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev) 492 { 493 struct stk8312_data *data = iio_priv(indio_dev); 494 495 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); 496 } 497 498 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = { 499 .preenable = stk8312_buffer_preenable, 500 .postenable = iio_triggered_buffer_postenable, 501 .predisable = iio_triggered_buffer_predisable, 502 .postdisable = stk8312_buffer_postdisable, 503 }; 504 505 static int stk8312_probe(struct i2c_client *client, 506 const struct i2c_device_id *id) 507 { 508 int ret; 509 struct iio_dev *indio_dev; 510 struct stk8312_data *data; 511 512 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 513 if (!indio_dev) { 514 dev_err(&client->dev, "iio allocation failed!\n"); 515 return -ENOMEM; 516 } 517 518 data = iio_priv(indio_dev); 519 data->client = client; 520 i2c_set_clientdata(client, indio_dev); 521 mutex_init(&data->lock); 522 523 indio_dev->dev.parent = &client->dev; 524 indio_dev->info = &stk8312_info; 525 indio_dev->name = STK8312_DRIVER_NAME; 526 indio_dev->modes = INDIO_DIRECT_MODE; 527 indio_dev->channels = stk8312_channels; 528 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels); 529 530 /* A software reset is recommended at power-on */ 531 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00); 532 if (ret < 0) { 533 dev_err(&client->dev, "failed to reset sensor\n"); 534 return ret; 535 } 536 data->sample_rate_idx = STK8312_SR_400HZ_IDX; 537 ret = stk8312_set_range(data, STK8312_RNG_6G); 538 if (ret < 0) 539 return ret; 540 541 ret = stk8312_set_mode(data, 542 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE); 543 if (ret < 0) 544 return ret; 545 546 if (client->irq > 0) { 547 ret = devm_request_threaded_irq(&client->dev, client->irq, 548 stk8312_data_rdy_trig_poll, 549 NULL, 550 IRQF_TRIGGER_RISING | 551 IRQF_ONESHOT, 552 STK8312_IRQ_NAME, 553 indio_dev); 554 if (ret < 0) { 555 dev_err(&client->dev, "request irq %d failed\n", 556 client->irq); 557 goto err_power_off; 558 } 559 560 data->dready_trig = devm_iio_trigger_alloc(&client->dev, 561 "%s-dev%d", 562 indio_dev->name, 563 indio_dev->id); 564 if (!data->dready_trig) { 565 ret = -ENOMEM; 566 goto err_power_off; 567 } 568 569 data->dready_trig->dev.parent = &client->dev; 570 data->dready_trig->ops = &stk8312_trigger_ops; 571 iio_trigger_set_drvdata(data->dready_trig, indio_dev); 572 ret = iio_trigger_register(data->dready_trig); 573 if (ret) { 574 dev_err(&client->dev, "iio trigger register failed\n"); 575 goto err_power_off; 576 } 577 } 578 579 ret = iio_triggered_buffer_setup(indio_dev, 580 iio_pollfunc_store_time, 581 stk8312_trigger_handler, 582 &stk8312_buffer_setup_ops); 583 if (ret < 0) { 584 dev_err(&client->dev, "iio triggered buffer setup failed\n"); 585 goto err_trigger_unregister; 586 } 587 588 ret = iio_device_register(indio_dev); 589 if (ret < 0) { 590 dev_err(&client->dev, "device_register failed\n"); 591 goto err_buffer_cleanup; 592 } 593 594 return 0; 595 596 err_buffer_cleanup: 597 iio_triggered_buffer_cleanup(indio_dev); 598 err_trigger_unregister: 599 if (data->dready_trig) 600 iio_trigger_unregister(data->dready_trig); 601 err_power_off: 602 stk8312_set_mode(data, STK8312_MODE_STANDBY); 603 return ret; 604 } 605 606 static int stk8312_remove(struct i2c_client *client) 607 { 608 struct iio_dev *indio_dev = i2c_get_clientdata(client); 609 struct stk8312_data *data = iio_priv(indio_dev); 610 611 iio_device_unregister(indio_dev); 612 iio_triggered_buffer_cleanup(indio_dev); 613 614 if (data->dready_trig) 615 iio_trigger_unregister(data->dready_trig); 616 617 return stk8312_set_mode(data, STK8312_MODE_STANDBY); 618 } 619 620 #ifdef CONFIG_PM_SLEEP 621 static int stk8312_suspend(struct device *dev) 622 { 623 struct stk8312_data *data; 624 625 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 626 627 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE)); 628 } 629 630 static int stk8312_resume(struct device *dev) 631 { 632 struct stk8312_data *data; 633 634 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 635 636 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE); 637 } 638 639 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume); 640 641 #define STK8312_PM_OPS (&stk8312_pm_ops) 642 #else 643 #define STK8312_PM_OPS NULL 644 #endif 645 646 static const struct i2c_device_id stk8312_i2c_id[] = { 647 {"STK8312", 0}, 648 {} 649 }; 650 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id); 651 652 static const struct acpi_device_id stk8312_acpi_id[] = { 653 {"STK8312", 0}, 654 {} 655 }; 656 657 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id); 658 659 static struct i2c_driver stk8312_driver = { 660 .driver = { 661 .name = STK8312_DRIVER_NAME, 662 .pm = STK8312_PM_OPS, 663 .acpi_match_table = ACPI_PTR(stk8312_acpi_id), 664 }, 665 .probe = stk8312_probe, 666 .remove = stk8312_remove, 667 .id_table = stk8312_i2c_id, 668 }; 669 670 module_i2c_driver(stk8312_driver); 671 672 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>"); 673 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver"); 674 MODULE_LICENSE("GPL v2"); 675