1 /* 2 * STMicroelectronics pressures driver 3 * 4 * Copyright 2013 STMicroelectronics Inc. 5 * 6 * Denis Ciocca <denis.ciocca@st.com> 7 * 8 * Licensed under the GPL-2. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/errno.h> 15 #include <linux/types.h> 16 #include <linux/mutex.h> 17 #include <linux/interrupt.h> 18 #include <linux/i2c.h> 19 #include <linux/gpio.h> 20 #include <linux/irq.h> 21 #include <linux/delay.h> 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 #include <linux/iio/trigger.h> 25 #include <linux/iio/buffer.h> 26 #include <asm/unaligned.h> 27 28 #include <linux/iio/common/st_sensors.h> 29 #include "st_pressure.h" 30 31 /* 32 * About determining pressure scaling factors 33 * ------------------------------------------ 34 * 35 * Datasheets specify typical pressure sensitivity so that pressure is computed 36 * according to the following equation : 37 * pressure[mBar] = raw / sensitivity 38 * where : 39 * raw the 24 bits long raw sampled pressure 40 * sensitivity a scaling factor specified by the datasheet in LSB/mBar 41 * 42 * IIO ABI expects pressure to be expressed as kPascal, hence pressure should be 43 * computed according to : 44 * pressure[kPascal] = pressure[mBar] / 10 45 * = raw / (sensitivity * 10) (1) 46 * 47 * Finally, st_press_read_raw() returns pressure scaling factor as an 48 * IIO_VAL_INT_PLUS_NANO with a zero integral part and "gain" as decimal part. 49 * Therefore, from (1), "gain" becomes : 50 * gain = 10^9 / (sensitivity * 10) 51 * = 10^8 / sensitivity 52 * 53 * About determining temperature scaling factors and offsets 54 * --------------------------------------------------------- 55 * 56 * Datasheets specify typical temperature sensitivity and offset so that 57 * temperature is computed according to the following equation : 58 * temp[Celsius] = offset[Celsius] + (raw / sensitivity) 59 * where : 60 * raw the 16 bits long raw sampled temperature 61 * offset a constant specified by the datasheet in degree Celsius 62 * (sometimes zero) 63 * sensitivity a scaling factor specified by the datasheet in LSB/Celsius 64 * 65 * IIO ABI expects temperature to be expressed as milli degree Celsius such as 66 * user space should compute temperature according to : 67 * temp[mCelsius] = temp[Celsius] * 10^3 68 * = (offset[Celsius] + (raw / sensitivity)) * 10^3 69 * = ((offset[Celsius] * sensitivity) + raw) * 70 * (10^3 / sensitivity) (2) 71 * 72 * IIO ABI expects user space to apply offset and scaling factors to raw samples 73 * according to : 74 * temp[mCelsius] = (OFFSET + raw) * SCALE 75 * where : 76 * OFFSET an arbitrary constant exposed by device 77 * SCALE an arbitrary scaling factor exposed by device 78 * 79 * Matching OFFSET and SCALE with members of (2) gives : 80 * OFFSET = offset[Celsius] * sensitivity (3) 81 * SCALE = 10^3 / sensitivity (4) 82 * 83 * st_press_read_raw() returns temperature scaling factor as an 84 * IIO_VAL_FRACTIONAL with a 10^3 numerator and "gain2" as denominator. 85 * Therefore, from (3), "gain2" becomes : 86 * gain2 = sensitivity 87 * 88 * When declared within channel, i.e. for a non zero specified offset, 89 * st_press_read_raw() will return the latter as an IIO_VAL_FRACTIONAL such as : 90 * numerator = OFFSET * 10^3 91 * denominator = 10^3 92 * giving from (4): 93 * numerator = offset[Celsius] * 10^3 * sensitivity 94 * = offset[mCelsius] * gain2 95 */ 96 97 #define MCELSIUS_PER_CELSIUS 1000 98 99 /* Default pressure sensitivity */ 100 #define ST_PRESS_LSB_PER_MBAR 4096UL 101 #define ST_PRESS_KPASCAL_NANO_SCALE (100000000UL / \ 102 ST_PRESS_LSB_PER_MBAR) 103 104 /* Default temperature sensitivity */ 105 #define ST_PRESS_LSB_PER_CELSIUS 480UL 106 #define ST_PRESS_MILLI_CELSIUS_OFFSET 42500UL 107 108 /* FULLSCALE */ 109 #define ST_PRESS_FS_AVL_1100MB 1100 110 #define ST_PRESS_FS_AVL_1260MB 1260 111 112 #define ST_PRESS_1_OUT_XL_ADDR 0x28 113 #define ST_TEMP_1_OUT_L_ADDR 0x2b 114 115 /* LPS001WP pressure resolution */ 116 #define ST_PRESS_LPS001WP_LSB_PER_MBAR 16UL 117 /* LPS001WP temperature resolution */ 118 #define ST_PRESS_LPS001WP_LSB_PER_CELSIUS 64UL 119 /* LPS001WP pressure gain */ 120 #define ST_PRESS_LPS001WP_FS_AVL_PRESS_GAIN \ 121 (100000000UL / ST_PRESS_LPS001WP_LSB_PER_MBAR) 122 /* LPS001WP pressure and temp L addresses */ 123 #define ST_PRESS_LPS001WP_OUT_L_ADDR 0x28 124 #define ST_TEMP_LPS001WP_OUT_L_ADDR 0x2a 125 126 /* LPS25H pressure and temp L addresses */ 127 #define ST_PRESS_LPS25H_OUT_XL_ADDR 0x28 128 #define ST_TEMP_LPS25H_OUT_L_ADDR 0x2b 129 130 /* LPS22HB temperature sensitivity */ 131 #define ST_PRESS_LPS22HB_LSB_PER_CELSIUS 100UL 132 133 static const struct iio_chan_spec st_press_1_channels[] = { 134 { 135 .type = IIO_PRESSURE, 136 .address = ST_PRESS_1_OUT_XL_ADDR, 137 .scan_index = 0, 138 .scan_type = { 139 .sign = 'u', 140 .realbits = 24, 141 .storagebits = 32, 142 .endianness = IIO_LE, 143 }, 144 .info_mask_separate = 145 BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), 146 }, 147 { 148 .type = IIO_TEMP, 149 .address = ST_TEMP_1_OUT_L_ADDR, 150 .scan_index = 1, 151 .scan_type = { 152 .sign = 'u', 153 .realbits = 16, 154 .storagebits = 16, 155 .endianness = IIO_LE, 156 }, 157 .info_mask_separate = 158 BIT(IIO_CHAN_INFO_RAW) | 159 BIT(IIO_CHAN_INFO_SCALE) | 160 BIT(IIO_CHAN_INFO_OFFSET), 161 }, 162 IIO_CHAN_SOFT_TIMESTAMP(2) 163 }; 164 165 static const struct iio_chan_spec st_press_lps001wp_channels[] = { 166 { 167 .type = IIO_PRESSURE, 168 .address = ST_PRESS_LPS001WP_OUT_L_ADDR, 169 .scan_index = 0, 170 .scan_type = { 171 .sign = 'u', 172 .realbits = 16, 173 .storagebits = 16, 174 .endianness = IIO_LE, 175 }, 176 .info_mask_separate = 177 BIT(IIO_CHAN_INFO_RAW) | 178 BIT(IIO_CHAN_INFO_SCALE), 179 }, 180 { 181 .type = IIO_TEMP, 182 .address = ST_TEMP_LPS001WP_OUT_L_ADDR, 183 .scan_index = 1, 184 .scan_type = { 185 .sign = 'u', 186 .realbits = 16, 187 .storagebits = 16, 188 .endianness = IIO_LE, 189 }, 190 .info_mask_separate = 191 BIT(IIO_CHAN_INFO_RAW) | 192 BIT(IIO_CHAN_INFO_SCALE), 193 }, 194 IIO_CHAN_SOFT_TIMESTAMP(2) 195 }; 196 197 static const struct iio_chan_spec st_press_lps22hb_channels[] = { 198 { 199 .type = IIO_PRESSURE, 200 .address = ST_PRESS_1_OUT_XL_ADDR, 201 .scan_index = 0, 202 .scan_type = { 203 .sign = 'u', 204 .realbits = 24, 205 .storagebits = 32, 206 .endianness = IIO_LE, 207 }, 208 .info_mask_separate = 209 BIT(IIO_CHAN_INFO_RAW) | 210 BIT(IIO_CHAN_INFO_SCALE), 211 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), 212 }, 213 { 214 .type = IIO_TEMP, 215 .address = ST_TEMP_1_OUT_L_ADDR, 216 .scan_index = 1, 217 .scan_type = { 218 .sign = 's', 219 .realbits = 16, 220 .storagebits = 16, 221 .endianness = IIO_LE, 222 }, 223 .info_mask_separate = 224 BIT(IIO_CHAN_INFO_RAW) | 225 BIT(IIO_CHAN_INFO_SCALE), 226 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), 227 }, 228 IIO_CHAN_SOFT_TIMESTAMP(2) 229 }; 230 231 static const struct st_sensor_settings st_press_sensors_settings[] = { 232 { 233 /* 234 * CUSTOM VALUES FOR LPS331AP SENSOR 235 * See LPS331AP datasheet: 236 * http://www2.st.com/resource/en/datasheet/lps331ap.pdf 237 */ 238 .wai = 0xbb, 239 .wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS, 240 .sensors_supported = { 241 [0] = LPS331AP_PRESS_DEV_NAME, 242 }, 243 .ch = (struct iio_chan_spec *)st_press_1_channels, 244 .num_ch = ARRAY_SIZE(st_press_1_channels), 245 .odr = { 246 .addr = 0x20, 247 .mask = 0x70, 248 .odr_avl = { 249 { .hz = 1, .value = 0x01 }, 250 { .hz = 7, .value = 0x05 }, 251 { .hz = 13, .value = 0x06 }, 252 { .hz = 25, .value = 0x07 }, 253 }, 254 }, 255 .pw = { 256 .addr = 0x20, 257 .mask = 0x80, 258 .value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE, 259 .value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE, 260 }, 261 .fs = { 262 .addr = 0x23, 263 .mask = 0x30, 264 .fs_avl = { 265 /* 266 * Pressure and temperature sensitivity values 267 * as defined in table 3 of LPS331AP datasheet. 268 */ 269 [0] = { 270 .num = ST_PRESS_FS_AVL_1260MB, 271 .gain = ST_PRESS_KPASCAL_NANO_SCALE, 272 .gain2 = ST_PRESS_LSB_PER_CELSIUS, 273 }, 274 }, 275 }, 276 .bdu = { 277 .addr = 0x20, 278 .mask = 0x04, 279 }, 280 .drdy_irq = { 281 .addr = 0x22, 282 .mask_int1 = 0x04, 283 .mask_int2 = 0x20, 284 .addr_ihl = 0x22, 285 .mask_ihl = 0x80, 286 .addr_od = 0x22, 287 .mask_od = 0x40, 288 .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR, 289 }, 290 .multi_read_bit = true, 291 .bootime = 2, 292 }, 293 { 294 /* 295 * CUSTOM VALUES FOR LPS001WP SENSOR 296 */ 297 .wai = 0xba, 298 .wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS, 299 .sensors_supported = { 300 [0] = LPS001WP_PRESS_DEV_NAME, 301 }, 302 .ch = (struct iio_chan_spec *)st_press_lps001wp_channels, 303 .num_ch = ARRAY_SIZE(st_press_lps001wp_channels), 304 .odr = { 305 .addr = 0x20, 306 .mask = 0x30, 307 .odr_avl = { 308 { .hz = 1, .value = 0x01 }, 309 { .hz = 7, .value = 0x02 }, 310 { .hz = 13, .value = 0x03 }, 311 }, 312 }, 313 .pw = { 314 .addr = 0x20, 315 .mask = 0x40, 316 .value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE, 317 .value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE, 318 }, 319 .fs = { 320 .fs_avl = { 321 /* 322 * Pressure and temperature resolution values 323 * as defined in table 3 of LPS001WP datasheet. 324 */ 325 [0] = { 326 .num = ST_PRESS_FS_AVL_1100MB, 327 .gain = ST_PRESS_LPS001WP_FS_AVL_PRESS_GAIN, 328 .gain2 = ST_PRESS_LPS001WP_LSB_PER_CELSIUS, 329 }, 330 }, 331 }, 332 .bdu = { 333 .addr = 0x20, 334 .mask = 0x04, 335 }, 336 .drdy_irq = { 337 .addr = 0, 338 }, 339 .multi_read_bit = true, 340 .bootime = 2, 341 }, 342 { 343 /* 344 * CUSTOM VALUES FOR LPS25H SENSOR 345 * See LPS25H datasheet: 346 * http://www2.st.com/resource/en/datasheet/lps25h.pdf 347 */ 348 .wai = 0xbd, 349 .wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS, 350 .sensors_supported = { 351 [0] = LPS25H_PRESS_DEV_NAME, 352 }, 353 .ch = (struct iio_chan_spec *)st_press_1_channels, 354 .num_ch = ARRAY_SIZE(st_press_1_channels), 355 .odr = { 356 .addr = 0x20, 357 .mask = 0x70, 358 .odr_avl = { 359 { .hz = 1, .value = 0x01 }, 360 { .hz = 7, .value = 0x02 }, 361 { .hz = 13, .value = 0x03 }, 362 { .hz = 25, .value = 0x04 }, 363 }, 364 }, 365 .pw = { 366 .addr = 0x20, 367 .mask = 0x80, 368 .value_on = ST_SENSORS_DEFAULT_POWER_ON_VALUE, 369 .value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE, 370 }, 371 .fs = { 372 .fs_avl = { 373 /* 374 * Pressure and temperature sensitivity values 375 * as defined in table 3 of LPS25H datasheet. 376 */ 377 [0] = { 378 .num = ST_PRESS_FS_AVL_1260MB, 379 .gain = ST_PRESS_KPASCAL_NANO_SCALE, 380 .gain2 = ST_PRESS_LSB_PER_CELSIUS, 381 }, 382 }, 383 }, 384 .bdu = { 385 .addr = 0x20, 386 .mask = 0x04, 387 }, 388 .drdy_irq = { 389 .addr = 0x23, 390 .mask_int1 = 0x01, 391 .mask_int2 = 0x10, 392 .addr_ihl = 0x22, 393 .mask_ihl = 0x80, 394 .addr_od = 0x22, 395 .mask_od = 0x40, 396 .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR, 397 }, 398 .multi_read_bit = true, 399 .bootime = 2, 400 }, 401 { 402 /* 403 * CUSTOM VALUES FOR LPS22HB SENSOR 404 * See LPS22HB datasheet: 405 * http://www2.st.com/resource/en/datasheet/lps22hb.pdf 406 */ 407 .wai = 0xb1, 408 .wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS, 409 .sensors_supported = { 410 [0] = LPS22HB_PRESS_DEV_NAME, 411 }, 412 .ch = (struct iio_chan_spec *)st_press_lps22hb_channels, 413 .num_ch = ARRAY_SIZE(st_press_lps22hb_channels), 414 .odr = { 415 .addr = 0x10, 416 .mask = 0x70, 417 .odr_avl = { 418 { .hz = 1, .value = 0x01 }, 419 { .hz = 10, .value = 0x02 }, 420 { .hz = 25, .value = 0x03 }, 421 { .hz = 50, .value = 0x04 }, 422 { .hz = 75, .value = 0x05 }, 423 }, 424 }, 425 .pw = { 426 .addr = 0x10, 427 .mask = 0x70, 428 .value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE, 429 }, 430 .fs = { 431 .fs_avl = { 432 /* 433 * Pressure and temperature sensitivity values 434 * as defined in table 3 of LPS22HB datasheet. 435 */ 436 [0] = { 437 .num = ST_PRESS_FS_AVL_1260MB, 438 .gain = ST_PRESS_KPASCAL_NANO_SCALE, 439 .gain2 = ST_PRESS_LPS22HB_LSB_PER_CELSIUS, 440 }, 441 }, 442 }, 443 .bdu = { 444 .addr = 0x10, 445 .mask = 0x02, 446 }, 447 .drdy_irq = { 448 .addr = 0x12, 449 .mask_int1 = 0x04, 450 .mask_int2 = 0x08, 451 .addr_ihl = 0x12, 452 .mask_ihl = 0x80, 453 .addr_od = 0x12, 454 .mask_od = 0x40, 455 .addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR, 456 }, 457 .multi_read_bit = true, 458 }, 459 }; 460 461 static int st_press_write_raw(struct iio_dev *indio_dev, 462 struct iio_chan_spec const *ch, 463 int val, 464 int val2, 465 long mask) 466 { 467 int err; 468 469 switch (mask) { 470 case IIO_CHAN_INFO_SAMP_FREQ: 471 if (val2) 472 return -EINVAL; 473 mutex_lock(&indio_dev->mlock); 474 err = st_sensors_set_odr(indio_dev, val); 475 mutex_unlock(&indio_dev->mlock); 476 return err; 477 default: 478 return -EINVAL; 479 } 480 } 481 482 static int st_press_read_raw(struct iio_dev *indio_dev, 483 struct iio_chan_spec const *ch, int *val, 484 int *val2, long mask) 485 { 486 int err; 487 struct st_sensor_data *press_data = iio_priv(indio_dev); 488 489 switch (mask) { 490 case IIO_CHAN_INFO_RAW: 491 err = st_sensors_read_info_raw(indio_dev, ch, val); 492 if (err < 0) 493 goto read_error; 494 495 return IIO_VAL_INT; 496 case IIO_CHAN_INFO_SCALE: 497 switch (ch->type) { 498 case IIO_PRESSURE: 499 *val = 0; 500 *val2 = press_data->current_fullscale->gain; 501 return IIO_VAL_INT_PLUS_NANO; 502 case IIO_TEMP: 503 *val = MCELSIUS_PER_CELSIUS; 504 *val2 = press_data->current_fullscale->gain2; 505 return IIO_VAL_FRACTIONAL; 506 default: 507 err = -EINVAL; 508 goto read_error; 509 } 510 511 case IIO_CHAN_INFO_OFFSET: 512 switch (ch->type) { 513 case IIO_TEMP: 514 *val = ST_PRESS_MILLI_CELSIUS_OFFSET * 515 press_data->current_fullscale->gain2; 516 *val2 = MCELSIUS_PER_CELSIUS; 517 break; 518 default: 519 err = -EINVAL; 520 goto read_error; 521 } 522 523 return IIO_VAL_FRACTIONAL; 524 case IIO_CHAN_INFO_SAMP_FREQ: 525 *val = press_data->odr; 526 return IIO_VAL_INT; 527 default: 528 return -EINVAL; 529 } 530 531 read_error: 532 return err; 533 } 534 535 static ST_SENSORS_DEV_ATTR_SAMP_FREQ_AVAIL(); 536 537 static struct attribute *st_press_attributes[] = { 538 &iio_dev_attr_sampling_frequency_available.dev_attr.attr, 539 NULL, 540 }; 541 542 static const struct attribute_group st_press_attribute_group = { 543 .attrs = st_press_attributes, 544 }; 545 546 static const struct iio_info press_info = { 547 .driver_module = THIS_MODULE, 548 .attrs = &st_press_attribute_group, 549 .read_raw = &st_press_read_raw, 550 .write_raw = &st_press_write_raw, 551 .debugfs_reg_access = &st_sensors_debugfs_reg_access, 552 }; 553 554 #ifdef CONFIG_IIO_TRIGGER 555 static const struct iio_trigger_ops st_press_trigger_ops = { 556 .owner = THIS_MODULE, 557 .set_trigger_state = ST_PRESS_TRIGGER_SET_STATE, 558 .validate_device = st_sensors_validate_device, 559 }; 560 #define ST_PRESS_TRIGGER_OPS (&st_press_trigger_ops) 561 #else 562 #define ST_PRESS_TRIGGER_OPS NULL 563 #endif 564 565 int st_press_common_probe(struct iio_dev *indio_dev) 566 { 567 struct st_sensor_data *press_data = iio_priv(indio_dev); 568 int irq = press_data->get_irq_data_ready(indio_dev); 569 int err; 570 571 indio_dev->modes = INDIO_DIRECT_MODE; 572 indio_dev->info = &press_info; 573 mutex_init(&press_data->tb.buf_lock); 574 575 err = st_sensors_power_enable(indio_dev); 576 if (err) 577 return err; 578 579 err = st_sensors_check_device_support(indio_dev, 580 ARRAY_SIZE(st_press_sensors_settings), 581 st_press_sensors_settings); 582 if (err < 0) 583 goto st_press_power_off; 584 585 /* 586 * Skip timestamping channel while declaring available channels to 587 * common st_sensor layer. Look at st_sensors_get_buffer_element() to 588 * see how timestamps are explicitly pushed as last samples block 589 * element. 590 */ 591 press_data->num_data_channels = press_data->sensor_settings->num_ch - 1; 592 press_data->multiread_bit = press_data->sensor_settings->multi_read_bit; 593 indio_dev->channels = press_data->sensor_settings->ch; 594 indio_dev->num_channels = press_data->sensor_settings->num_ch; 595 596 press_data->current_fullscale = 597 (struct st_sensor_fullscale_avl *) 598 &press_data->sensor_settings->fs.fs_avl[0]; 599 600 press_data->odr = press_data->sensor_settings->odr.odr_avl[0].hz; 601 602 /* Some devices don't support a data ready pin. */ 603 if (!press_data->dev->platform_data && 604 press_data->sensor_settings->drdy_irq.addr) 605 press_data->dev->platform_data = 606 (struct st_sensors_platform_data *)&default_press_pdata; 607 608 err = st_sensors_init_sensor(indio_dev, press_data->dev->platform_data); 609 if (err < 0) 610 goto st_press_power_off; 611 612 err = st_press_allocate_ring(indio_dev); 613 if (err < 0) 614 goto st_press_power_off; 615 616 if (irq > 0) { 617 err = st_sensors_allocate_trigger(indio_dev, 618 ST_PRESS_TRIGGER_OPS); 619 if (err < 0) 620 goto st_press_probe_trigger_error; 621 } 622 623 err = iio_device_register(indio_dev); 624 if (err) 625 goto st_press_device_register_error; 626 627 dev_info(&indio_dev->dev, "registered pressure sensor %s\n", 628 indio_dev->name); 629 630 return err; 631 632 st_press_device_register_error: 633 if (irq > 0) 634 st_sensors_deallocate_trigger(indio_dev); 635 st_press_probe_trigger_error: 636 st_press_deallocate_ring(indio_dev); 637 st_press_power_off: 638 st_sensors_power_disable(indio_dev); 639 640 return err; 641 } 642 EXPORT_SYMBOL(st_press_common_probe); 643 644 void st_press_common_remove(struct iio_dev *indio_dev) 645 { 646 struct st_sensor_data *press_data = iio_priv(indio_dev); 647 648 st_sensors_power_disable(indio_dev); 649 650 iio_device_unregister(indio_dev); 651 if (press_data->get_irq_data_ready(indio_dev) > 0) 652 st_sensors_deallocate_trigger(indio_dev); 653 654 st_press_deallocate_ring(indio_dev); 655 } 656 EXPORT_SYMBOL(st_press_common_remove); 657 658 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 659 MODULE_DESCRIPTION("STMicroelectronics pressures driver"); 660 MODULE_LICENSE("GPL v2"); 661