1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Support code for Analog Devices Sigma-Delta ADCs 4 * 5 * Copyright 2012 Analog Devices Inc. 6 * Author: Lars-Peter Clausen <lars@metafoo.de> 7 */ 8 9 #include <linux/align.h> 10 #include <linux/interrupt.h> 11 #include <linux/device.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 #include <linux/spi/spi.h> 15 #include <linux/err.h> 16 #include <linux/module.h> 17 18 #include <linux/iio/iio.h> 19 #include <linux/iio/sysfs.h> 20 #include <linux/iio/buffer.h> 21 #include <linux/iio/trigger.h> 22 #include <linux/iio/trigger_consumer.h> 23 #include <linux/iio/triggered_buffer.h> 24 #include <linux/iio/adc/ad_sigma_delta.h> 25 26 #include <linux/unaligned.h> 27 28 29 #define AD_SD_COMM_CHAN_MASK 0x3 30 31 #define AD_SD_REG_COMM 0x00 32 #define AD_SD_REG_STATUS 0x00 33 #define AD_SD_REG_DATA 0x03 34 35 #define AD_SD_REG_STATUS_RDY 0x80 36 37 /** 38 * ad_sd_set_comm() - Set communications register 39 * 40 * @sigma_delta: The sigma delta device 41 * @comm: New value for the communications register 42 */ 43 void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm) 44 { 45 /* Some variants use the lower two bits of the communications register 46 * to select the channel */ 47 sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK; 48 } 49 EXPORT_SYMBOL_NS_GPL(ad_sd_set_comm, "IIO_AD_SIGMA_DELTA"); 50 51 /** 52 * ad_sd_write_reg() - Write a register 53 * 54 * @sigma_delta: The sigma delta device 55 * @reg: Address of the register 56 * @size: Size of the register (0-3) 57 * @val: Value to write to the register 58 * 59 * Returns 0 on success, an error code otherwise. 60 **/ 61 int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg, 62 unsigned int size, unsigned int val) 63 { 64 uint8_t *data = sigma_delta->tx_buf; 65 struct spi_transfer t = { 66 .tx_buf = data, 67 .len = size + 1, 68 .cs_change = sigma_delta->keep_cs_asserted, 69 }; 70 struct spi_message m; 71 int ret; 72 73 data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm; 74 75 switch (size) { 76 case 3: 77 put_unaligned_be24(val, &data[1]); 78 break; 79 case 2: 80 put_unaligned_be16(val, &data[1]); 81 break; 82 case 1: 83 data[1] = val; 84 break; 85 case 0: 86 break; 87 default: 88 return -EINVAL; 89 } 90 91 spi_message_init(&m); 92 spi_message_add_tail(&t, &m); 93 94 if (sigma_delta->bus_locked) 95 ret = spi_sync_locked(sigma_delta->spi, &m); 96 else 97 ret = spi_sync(sigma_delta->spi, &m); 98 99 return ret; 100 } 101 EXPORT_SYMBOL_NS_GPL(ad_sd_write_reg, "IIO_AD_SIGMA_DELTA"); 102 103 static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta, 104 unsigned int reg, unsigned int size, uint8_t *val) 105 { 106 uint8_t *data = sigma_delta->tx_buf; 107 int ret; 108 struct spi_transfer t[] = { 109 { 110 .tx_buf = data, 111 .len = 1, 112 }, { 113 .rx_buf = val, 114 .len = size, 115 .cs_change = sigma_delta->keep_cs_asserted, 116 }, 117 }; 118 struct spi_message m; 119 120 spi_message_init(&m); 121 122 if (sigma_delta->info->has_registers) { 123 data[0] = reg << sigma_delta->info->addr_shift; 124 data[0] |= sigma_delta->info->read_mask; 125 data[0] |= sigma_delta->comm; 126 spi_message_add_tail(&t[0], &m); 127 } 128 spi_message_add_tail(&t[1], &m); 129 130 if (sigma_delta->bus_locked) 131 ret = spi_sync_locked(sigma_delta->spi, &m); 132 else 133 ret = spi_sync(sigma_delta->spi, &m); 134 135 return ret; 136 } 137 138 /** 139 * ad_sd_read_reg() - Read a register 140 * 141 * @sigma_delta: The sigma delta device 142 * @reg: Address of the register 143 * @size: Size of the register (1-4) 144 * @val: Read value 145 * 146 * Returns 0 on success, an error code otherwise. 147 **/ 148 int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta, 149 unsigned int reg, unsigned int size, unsigned int *val) 150 { 151 int ret; 152 153 ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->rx_buf); 154 if (ret < 0) 155 goto out; 156 157 switch (size) { 158 case 4: 159 *val = get_unaligned_be32(sigma_delta->rx_buf); 160 break; 161 case 3: 162 *val = get_unaligned_be24(sigma_delta->rx_buf); 163 break; 164 case 2: 165 *val = get_unaligned_be16(sigma_delta->rx_buf); 166 break; 167 case 1: 168 *val = sigma_delta->rx_buf[0]; 169 break; 170 default: 171 ret = -EINVAL; 172 break; 173 } 174 175 out: 176 return ret; 177 } 178 EXPORT_SYMBOL_NS_GPL(ad_sd_read_reg, "IIO_AD_SIGMA_DELTA"); 179 180 /** 181 * ad_sd_reset() - Reset the serial interface 182 * 183 * @sigma_delta: The sigma delta device 184 * 185 * Returns 0 on success, an error code otherwise. 186 **/ 187 int ad_sd_reset(struct ad_sigma_delta *sigma_delta) 188 { 189 unsigned int reset_length = sigma_delta->info->num_resetclks; 190 uint8_t *buf; 191 unsigned int size; 192 int ret; 193 194 size = DIV_ROUND_UP(reset_length, 8); 195 buf = kcalloc(size, sizeof(*buf), GFP_KERNEL); 196 if (!buf) 197 return -ENOMEM; 198 199 memset(buf, 0xff, size); 200 ret = spi_write(sigma_delta->spi, buf, size); 201 kfree(buf); 202 203 return ret; 204 } 205 EXPORT_SYMBOL_NS_GPL(ad_sd_reset, "IIO_AD_SIGMA_DELTA"); 206 207 static bool ad_sd_disable_irq(struct ad_sigma_delta *sigma_delta) 208 { 209 guard(spinlock_irqsave)(&sigma_delta->irq_lock); 210 211 /* It's already off, return false to indicate nothing was changed */ 212 if (sigma_delta->irq_dis) 213 return false; 214 215 sigma_delta->irq_dis = true; 216 disable_irq_nosync(sigma_delta->irq_line); 217 return true; 218 } 219 220 static void ad_sd_enable_irq(struct ad_sigma_delta *sigma_delta) 221 { 222 guard(spinlock_irqsave)(&sigma_delta->irq_lock); 223 224 sigma_delta->irq_dis = false; 225 enable_irq(sigma_delta->irq_line); 226 } 227 228 #define AD_SD_CLEAR_DATA_BUFLEN 9 229 230 /* Called with `sigma_delta->bus_locked == true` only. */ 231 static int ad_sigma_delta_clear_pending_event(struct ad_sigma_delta *sigma_delta) 232 { 233 bool pending_event; 234 unsigned int data_read_len = BITS_TO_BYTES(sigma_delta->info->num_resetclks); 235 u8 *data; 236 struct spi_transfer t[] = { 237 { 238 .len = 1, 239 }, { 240 .len = data_read_len, 241 } 242 }; 243 struct spi_message m; 244 int ret; 245 246 /* 247 * Read R̅D̅Y̅ pin (if possible) or status register to check if there is an 248 * old event. 249 */ 250 if (sigma_delta->rdy_gpiod) { 251 pending_event = gpiod_get_value(sigma_delta->rdy_gpiod); 252 } else { 253 unsigned int status_reg; 254 255 ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_STATUS, 1, &status_reg); 256 if (ret) 257 return ret; 258 259 pending_event = !(status_reg & AD_SD_REG_STATUS_RDY); 260 } 261 262 if (!pending_event) 263 return 0; 264 265 /* 266 * In general the size of the data register is unknown. It varies from 267 * device to device, might be one byte longer if CONTROL.DATA_STATUS is 268 * set and even varies on some devices depending on which input is 269 * selected. So send one byte to start reading the data register and 270 * then just clock for some bytes with DIN (aka MOSI) high to not 271 * confuse the register access state machine after the data register was 272 * completely read. Note however that the sequence length must be 273 * shorter than the reset procedure. 274 */ 275 276 data = kzalloc(data_read_len + 1, GFP_KERNEL); 277 if (!data) 278 return -ENOMEM; 279 280 spi_message_init(&m); 281 if (sigma_delta->info->has_registers) { 282 unsigned int data_reg = sigma_delta->info->data_reg ?: AD_SD_REG_DATA; 283 284 data[0] = data_reg << sigma_delta->info->addr_shift; 285 data[0] |= sigma_delta->info->read_mask; 286 data[0] |= sigma_delta->comm; 287 t[0].tx_buf = data; 288 spi_message_add_tail(&t[0], &m); 289 } 290 291 /* 292 * The first transferred byte is part of the real data register, 293 * so this doesn't need to be 0xff. In the remaining 294 * `data_read_len - 1` bytes are less than $num_resetclks ones. 295 */ 296 t[1].tx_buf = data + 1; 297 data[1] = 0x00; 298 memset(data + 2, 0xff, data_read_len - 1); 299 spi_message_add_tail(&t[1], &m); 300 301 ret = spi_sync_locked(sigma_delta->spi, &m); 302 303 kfree(data); 304 305 return ret; 306 } 307 308 int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta, 309 unsigned int mode, unsigned int channel) 310 { 311 int ret; 312 unsigned long time_left; 313 314 ret = ad_sigma_delta_set_channel(sigma_delta, channel); 315 if (ret) 316 return ret; 317 318 spi_bus_lock(sigma_delta->spi->controller); 319 sigma_delta->bus_locked = true; 320 sigma_delta->keep_cs_asserted = true; 321 reinit_completion(&sigma_delta->completion); 322 323 ret = ad_sigma_delta_clear_pending_event(sigma_delta); 324 if (ret) 325 goto out; 326 327 ret = ad_sigma_delta_set_mode(sigma_delta, mode); 328 if (ret < 0) 329 goto out; 330 331 ad_sd_enable_irq(sigma_delta); 332 time_left = wait_for_completion_timeout(&sigma_delta->completion, 2 * HZ); 333 if (time_left == 0) { 334 ad_sd_disable_irq(sigma_delta); 335 ret = -EIO; 336 } else { 337 ret = 0; 338 } 339 out: 340 sigma_delta->keep_cs_asserted = false; 341 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); 342 ad_sigma_delta_disable_one(sigma_delta, channel); 343 sigma_delta->bus_locked = false; 344 spi_bus_unlock(sigma_delta->spi->controller); 345 346 return ret; 347 } 348 EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate, "IIO_AD_SIGMA_DELTA"); 349 350 /** 351 * ad_sd_calibrate_all() - Performs channel calibration 352 * @sigma_delta: The sigma delta device 353 * @cb: Array of channels and calibration type to perform 354 * @n: Number of items in cb 355 * 356 * Returns 0 on success, an error code otherwise. 357 **/ 358 int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta, 359 const struct ad_sd_calib_data *cb, unsigned int n) 360 { 361 unsigned int i; 362 int ret; 363 364 for (i = 0; i < n; i++) { 365 ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel); 366 if (ret) 367 return ret; 368 } 369 370 return 0; 371 } 372 EXPORT_SYMBOL_NS_GPL(ad_sd_calibrate_all, "IIO_AD_SIGMA_DELTA"); 373 374 /** 375 * ad_sigma_delta_single_conversion() - Performs a single data conversion 376 * @indio_dev: The IIO device 377 * @chan: The conversion is done for this channel 378 * @val: Pointer to the location where to store the read value 379 * 380 * Returns: 0 on success, an error value otherwise. 381 */ 382 int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, 383 const struct iio_chan_spec *chan, int *val) 384 { 385 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 386 unsigned int sample, raw_sample; 387 unsigned int data_reg; 388 int ret = 0; 389 390 if (!iio_device_claim_direct(indio_dev)) 391 return -EBUSY; 392 393 ret = ad_sigma_delta_set_channel(sigma_delta, chan->address); 394 if (ret) 395 goto out_release; 396 397 spi_bus_lock(sigma_delta->spi->controller); 398 sigma_delta->bus_locked = true; 399 sigma_delta->keep_cs_asserted = true; 400 reinit_completion(&sigma_delta->completion); 401 402 ret = ad_sigma_delta_clear_pending_event(sigma_delta); 403 if (ret) 404 goto out_unlock; 405 406 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE); 407 408 ad_sd_enable_irq(sigma_delta); 409 ret = wait_for_completion_interruptible_timeout( 410 &sigma_delta->completion, HZ); 411 412 if (ret == 0) 413 ret = -EIO; 414 if (ret < 0) 415 goto out; 416 417 if (sigma_delta->info->data_reg != 0) 418 data_reg = sigma_delta->info->data_reg; 419 else 420 data_reg = AD_SD_REG_DATA; 421 422 ret = ad_sd_read_reg(sigma_delta, data_reg, 423 DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8), 424 &raw_sample); 425 426 out: 427 ad_sd_disable_irq(sigma_delta); 428 429 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); 430 ad_sigma_delta_disable_one(sigma_delta, chan->address); 431 432 out_unlock: 433 sigma_delta->keep_cs_asserted = false; 434 sigma_delta->bus_locked = false; 435 spi_bus_unlock(sigma_delta->spi->controller); 436 out_release: 437 iio_device_release_direct(indio_dev); 438 439 if (ret) 440 return ret; 441 442 sample = raw_sample >> chan->scan_type.shift; 443 sample &= (1 << chan->scan_type.realbits) - 1; 444 *val = sample; 445 446 ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample); 447 if (ret) 448 return ret; 449 450 return IIO_VAL_INT; 451 } 452 EXPORT_SYMBOL_NS_GPL(ad_sigma_delta_single_conversion, "IIO_AD_SIGMA_DELTA"); 453 454 static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) 455 { 456 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 457 unsigned int i, slot, samples_buf_size; 458 unsigned int channel; 459 uint8_t *samples_buf; 460 int ret; 461 462 if (sigma_delta->num_slots == 1) { 463 channel = find_first_bit(indio_dev->active_scan_mask, 464 iio_get_masklength(indio_dev)); 465 ret = ad_sigma_delta_set_channel(sigma_delta, 466 indio_dev->channels[channel].address); 467 if (ret) 468 return ret; 469 slot = 1; 470 } else { 471 /* 472 * At this point update_scan_mode already enabled the required channels. 473 * For sigma-delta sequencer drivers with multiple slots, an update_scan_mode 474 * implementation is mandatory. 475 */ 476 slot = 0; 477 iio_for_each_active_channel(indio_dev, i) { 478 sigma_delta->slots[slot] = indio_dev->channels[i].address; 479 slot++; 480 } 481 } 482 483 sigma_delta->active_slots = slot; 484 sigma_delta->current_slot = 0; 485 486 if (sigma_delta->active_slots > 1) { 487 ret = ad_sigma_delta_append_status(sigma_delta, true); 488 if (ret) 489 return ret; 490 } 491 492 samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8); 493 samples_buf_size += sizeof(int64_t); 494 samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf, 495 samples_buf_size, GFP_KERNEL); 496 if (!samples_buf) 497 return -ENOMEM; 498 499 sigma_delta->samples_buf = samples_buf; 500 501 spi_bus_lock(sigma_delta->spi->controller); 502 sigma_delta->bus_locked = true; 503 sigma_delta->keep_cs_asserted = true; 504 505 ret = ad_sigma_delta_clear_pending_event(sigma_delta); 506 if (ret) 507 goto err_unlock; 508 509 ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS); 510 if (ret) 511 goto err_unlock; 512 513 ad_sd_enable_irq(sigma_delta); 514 515 return 0; 516 517 err_unlock: 518 spi_bus_unlock(sigma_delta->spi->controller); 519 520 return ret; 521 } 522 523 static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev) 524 { 525 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 526 527 reinit_completion(&sigma_delta->completion); 528 wait_for_completion_timeout(&sigma_delta->completion, HZ); 529 530 ad_sd_disable_irq(sigma_delta); 531 532 sigma_delta->keep_cs_asserted = false; 533 ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); 534 535 if (sigma_delta->status_appended) 536 ad_sigma_delta_append_status(sigma_delta, false); 537 538 ad_sigma_delta_disable_all(sigma_delta); 539 sigma_delta->bus_locked = false; 540 return spi_bus_unlock(sigma_delta->spi->controller); 541 } 542 543 static irqreturn_t ad_sd_trigger_handler(int irq, void *p) 544 { 545 struct iio_poll_func *pf = p; 546 struct iio_dev *indio_dev = pf->indio_dev; 547 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 548 uint8_t *data = sigma_delta->rx_buf; 549 unsigned int transfer_size; 550 unsigned int sample_size; 551 unsigned int sample_pos; 552 unsigned int status_pos; 553 unsigned int reg_size; 554 unsigned int data_reg; 555 556 reg_size = indio_dev->channels[0].scan_type.realbits + 557 indio_dev->channels[0].scan_type.shift; 558 reg_size = DIV_ROUND_UP(reg_size, 8); 559 560 if (sigma_delta->info->data_reg != 0) 561 data_reg = sigma_delta->info->data_reg; 562 else 563 data_reg = AD_SD_REG_DATA; 564 565 /* Status word will be appended to the sample during transfer */ 566 if (sigma_delta->status_appended) 567 transfer_size = reg_size + 1; 568 else 569 transfer_size = reg_size; 570 571 switch (reg_size) { 572 case 4: 573 case 2: 574 case 1: 575 status_pos = reg_size; 576 ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[0]); 577 break; 578 case 3: 579 /* 580 * Data array after transfer will look like (if status is appended): 581 * data[] = { [0][sample][sample][sample][status] } 582 * Keeping the first byte 0 shifts the status position by 1 byte to the right. 583 */ 584 status_pos = reg_size + 1; 585 586 /* We store 24 bit samples in a 32 bit word. Keep the upper 587 * byte set to zero. */ 588 ad_sd_read_reg_raw(sigma_delta, data_reg, transfer_size, &data[1]); 589 break; 590 591 default: 592 dev_err_ratelimited(&indio_dev->dev, "Unsupported reg_size: %u\n", reg_size); 593 goto irq_handled; 594 } 595 596 /* 597 * For devices sampling only one channel at 598 * once, there is no need for sample number tracking. 599 */ 600 if (sigma_delta->active_slots == 1) { 601 iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp); 602 goto irq_handled; 603 } 604 605 if (sigma_delta->status_appended) { 606 u8 converted_channel; 607 608 converted_channel = data[status_pos] & sigma_delta->info->status_ch_mask; 609 if (converted_channel != sigma_delta->slots[sigma_delta->current_slot]) { 610 /* 611 * Desync occurred during continuous sampling of multiple channels. 612 * Drop this incomplete sample and start from first channel again. 613 */ 614 615 sigma_delta->current_slot = 0; 616 goto irq_handled; 617 } 618 } 619 620 sample_size = indio_dev->channels[0].scan_type.storagebits / 8; 621 sample_pos = sample_size * sigma_delta->current_slot; 622 memcpy(&sigma_delta->samples_buf[sample_pos], data, sample_size); 623 sigma_delta->current_slot++; 624 625 if (sigma_delta->current_slot == sigma_delta->active_slots) { 626 sigma_delta->current_slot = 0; 627 iio_push_to_buffers_with_timestamp(indio_dev, sigma_delta->samples_buf, 628 pf->timestamp); 629 } 630 631 irq_handled: 632 iio_trigger_notify_done(indio_dev->trig); 633 ad_sd_enable_irq(sigma_delta); 634 635 return IRQ_HANDLED; 636 } 637 638 static bool ad_sd_validate_scan_mask(struct iio_dev *indio_dev, const unsigned long *mask) 639 { 640 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 641 642 return bitmap_weight(mask, iio_get_masklength(indio_dev)) <= sigma_delta->num_slots; 643 } 644 645 static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = { 646 .postenable = &ad_sd_buffer_postenable, 647 .postdisable = &ad_sd_buffer_postdisable, 648 .validate_scan_mask = &ad_sd_validate_scan_mask, 649 }; 650 651 static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private) 652 { 653 struct ad_sigma_delta *sigma_delta = private; 654 655 /* 656 * AD7124 and a few others use the same physical line for interrupt 657 * reporting (R̅D̅Y̅) and MISO. 658 * As MISO toggles when reading a register, this likely results in a 659 * pending interrupt. This has two consequences: a) The irq might 660 * trigger immediately after it's enabled even though the conversion 661 * isn't done yet; and b) checking the STATUS register's R̅D̅Y̅ flag is 662 * off-limits as reading that would trigger another irq event. 663 * 664 * So read the MOSI line as GPIO (if available) and only trigger the irq 665 * if the line is active. Without such a GPIO assume this is a valid 666 * interrupt. 667 * 668 * Also as disable_irq_nosync() is used to disable the irq, only act if 669 * the irq wasn't disabled before. 670 */ 671 if ((!sigma_delta->rdy_gpiod || gpiod_get_value(sigma_delta->rdy_gpiod)) && 672 ad_sd_disable_irq(sigma_delta)) { 673 complete(&sigma_delta->completion); 674 iio_trigger_poll(sigma_delta->trig); 675 676 return IRQ_HANDLED; 677 } 678 679 return IRQ_NONE; 680 } 681 682 /** 683 * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices 684 * @indio_dev: The IIO device 685 * @trig: The new trigger 686 * 687 * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta 688 * device, -EINVAL otherwise. 689 */ 690 int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig) 691 { 692 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 693 694 if (sigma_delta->trig != trig) 695 return -EINVAL; 696 697 return 0; 698 } 699 EXPORT_SYMBOL_NS_GPL(ad_sd_validate_trigger, "IIO_AD_SIGMA_DELTA"); 700 701 static int devm_ad_sd_probe_trigger(struct device *dev, struct iio_dev *indio_dev) 702 { 703 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 704 unsigned long irq_flags = irq_get_trigger_type(sigma_delta->irq_line); 705 int ret; 706 707 if (dev != &sigma_delta->spi->dev) { 708 dev_err(dev, "Trigger parent should be '%s', got '%s'\n", 709 dev_name(dev), dev_name(&sigma_delta->spi->dev)); 710 return -EFAULT; 711 } 712 713 sigma_delta->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, 714 iio_device_id(indio_dev)); 715 if (sigma_delta->trig == NULL) 716 return -ENOMEM; 717 718 init_completion(&sigma_delta->completion); 719 720 sigma_delta->irq_dis = true; 721 722 /* the IRQ core clears IRQ_DISABLE_UNLAZY flag when freeing an IRQ */ 723 irq_set_status_flags(sigma_delta->irq_line, IRQ_DISABLE_UNLAZY); 724 725 /* Allow overwriting the flags from firmware */ 726 if (!irq_flags) 727 irq_flags = sigma_delta->info->irq_flags; 728 729 ret = devm_request_irq(dev, sigma_delta->irq_line, 730 ad_sd_data_rdy_trig_poll, 731 irq_flags | IRQF_NO_AUTOEN, 732 indio_dev->name, 733 sigma_delta); 734 if (ret) 735 return ret; 736 737 iio_trigger_set_drvdata(sigma_delta->trig, sigma_delta); 738 739 ret = devm_iio_trigger_register(dev, sigma_delta->trig); 740 if (ret) 741 return ret; 742 743 /* select default trigger */ 744 indio_dev->trig = iio_trigger_get(sigma_delta->trig); 745 746 return 0; 747 } 748 749 /** 750 * devm_ad_sd_setup_buffer_and_trigger() - Device-managed buffer & trigger setup 751 * @dev: Device object to which to bind the life-time of the resources attached 752 * @indio_dev: The IIO device 753 */ 754 int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indio_dev) 755 { 756 struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev); 757 int ret; 758 759 sigma_delta->slots = devm_kcalloc(dev, sigma_delta->num_slots, 760 sizeof(*sigma_delta->slots), GFP_KERNEL); 761 if (!sigma_delta->slots) 762 return -ENOMEM; 763 764 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 765 &iio_pollfunc_store_time, 766 &ad_sd_trigger_handler, 767 &ad_sd_buffer_setup_ops); 768 if (ret) 769 return ret; 770 771 return devm_ad_sd_probe_trigger(dev, indio_dev); 772 } 773 EXPORT_SYMBOL_NS_GPL(devm_ad_sd_setup_buffer_and_trigger, "IIO_AD_SIGMA_DELTA"); 774 775 /** 776 * ad_sd_init() - Initializes a ad_sigma_delta struct 777 * @sigma_delta: The ad_sigma_delta device 778 * @indio_dev: The IIO device which the Sigma Delta device is used for 779 * @spi: The SPI device for the ad_sigma_delta device 780 * @info: Device specific callbacks and options 781 * 782 * This function needs to be called before any other operations are performed on 783 * the ad_sigma_delta struct. 784 */ 785 int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev, 786 struct spi_device *spi, const struct ad_sigma_delta_info *info) 787 { 788 sigma_delta->spi = spi; 789 sigma_delta->info = info; 790 791 /* If the field is unset in ad_sigma_delta_info, assume there can only be 1 slot. */ 792 if (!info->num_slots) 793 sigma_delta->num_slots = 1; 794 else 795 sigma_delta->num_slots = info->num_slots; 796 797 if (sigma_delta->num_slots > 1) { 798 if (!indio_dev->info->update_scan_mode) { 799 dev_err(&spi->dev, "iio_dev lacks update_scan_mode().\n"); 800 return -EINVAL; 801 } 802 803 if (!info->disable_all) { 804 dev_err(&spi->dev, "ad_sigma_delta_info lacks disable_all().\n"); 805 return -EINVAL; 806 } 807 } 808 809 spin_lock_init(&sigma_delta->irq_lock); 810 811 if (info->has_named_irqs) { 812 sigma_delta->irq_line = fwnode_irq_get_byname(dev_fwnode(&spi->dev), 813 "rdy"); 814 if (sigma_delta->irq_line < 0) 815 return dev_err_probe(&spi->dev, sigma_delta->irq_line, 816 "Interrupt 'rdy' is required\n"); 817 } else { 818 sigma_delta->irq_line = spi->irq; 819 } 820 821 sigma_delta->rdy_gpiod = devm_gpiod_get_optional(&spi->dev, "rdy", GPIOD_IN); 822 if (IS_ERR(sigma_delta->rdy_gpiod)) 823 return dev_err_probe(&spi->dev, PTR_ERR(sigma_delta->rdy_gpiod), 824 "Failed to find rdy gpio\n"); 825 826 if (sigma_delta->rdy_gpiod && !sigma_delta->irq_line) { 827 sigma_delta->irq_line = gpiod_to_irq(sigma_delta->rdy_gpiod); 828 if (sigma_delta->irq_line < 0) 829 return sigma_delta->irq_line; 830 } 831 832 iio_device_set_drvdata(indio_dev, sigma_delta); 833 834 return 0; 835 } 836 EXPORT_SYMBOL_NS_GPL(ad_sd_init, "IIO_AD_SIGMA_DELTA"); 837 838 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 839 MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs"); 840 MODULE_LICENSE("GPL v2"); 841