1// SPDX-License-Identifier: GPL-2.0 2/* 3 * AD7606 SPI ADC driver 4 * 5 * Copyright 2011 Analog Devices Inc. 6 */ 7 8#include <linux/delay.h> 9#include <linux/device.h> 10#include <linux/err.h> 11#include <linux/gpio/consumer.h> 12#include <linux/interrupt.h> 13#include <linux/kernel.h> 14#include <linux/module.h> 15#include <linux/property.h> 16#include <linux/regulator/consumer.h> 17#include <linux/sched.h> 18#include <linux/slab.h> 19#include <linux/sysfs.h> 20#include <linux/util_macros.h> 21 22#include <linux/iio/iio.h> 23#include <linux/iio/buffer.h> 24#include <linux/iio/sysfs.h> 25#include <linux/iio/trigger.h> 26#include <linux/iio/triggered_buffer.h> 27#include <linux/iio/trigger_consumer.h> 28 29#include "ad7606.h" 30 31/* 32 * Scales are computed as 5000/32768 and 10000/32768 respectively, 33 * so that when applied to the raw values they provide mV values 34 */ 35static const unsigned int ad7606_scale_avail[2] = { 36 152588, 305176 37}; 38 39 40static const unsigned int ad7616_sw_scale_avail[3] = { 41 76293, 152588, 305176 42}; 43 44static const unsigned int ad7606_oversampling_avail[7] = { 45 1, 2, 4, 8, 16, 32, 64, 46}; 47 48static const unsigned int ad7616_oversampling_avail[8] = { 49 1, 2, 4, 8, 16, 32, 64, 128, 50}; 51 52static int ad7606_reset(struct ad7606_state *st) 53{ 54 if (st->gpio_reset) { 55 gpiod_set_value(st->gpio_reset, 1); 56 ndelay(100); /* t_reset >= 100ns */ 57 gpiod_set_value(st->gpio_reset, 0); 58 return 0; 59 } 60 61 return -ENODEV; 62} 63 64static int ad7606_reg_access(struct iio_dev *indio_dev, 65 unsigned int reg, 66 unsigned int writeval, 67 unsigned int *readval) 68{ 69 struct ad7606_state *st = iio_priv(indio_dev); 70 int ret; 71 72 mutex_lock(&st->lock); 73 if (readval) { 74 ret = st->bops->reg_read(st, reg); 75 if (ret < 0) 76 goto err_unlock; 77 *readval = ret; 78 ret = 0; 79 } else { 80 ret = st->bops->reg_write(st, reg, writeval); 81 } 82err_unlock: 83 mutex_unlock(&st->lock); 84 return ret; 85} 86 87static int ad7606_read_samples(struct ad7606_state *st) 88{ 89 unsigned int num = st->chip_info->num_channels - 1; 90 u16 *data = st->data; 91 int ret; 92 93 /* 94 * The frstdata signal is set to high while and after reading the sample 95 * of the first channel and low for all other channels. This can be used 96 * to check that the incoming data is correctly aligned. During normal 97 * operation the data should never become unaligned, but some glitch or 98 * electrostatic discharge might cause an extra read or clock cycle. 99 * Monitoring the frstdata signal allows to recover from such failure 100 * situations. 101 */ 102 103 if (st->gpio_frstdata) { 104 ret = st->bops->read_block(st->dev, 1, data); 105 if (ret) 106 return ret; 107 108 if (!gpiod_get_value(st->gpio_frstdata)) { 109 ad7606_reset(st); 110 return -EIO; 111 } 112 113 data++; 114 num--; 115 } 116 117 return st->bops->read_block(st->dev, num, data); 118} 119 120static irqreturn_t ad7606_trigger_handler(int irq, void *p) 121{ 122 struct iio_poll_func *pf = p; 123 struct iio_dev *indio_dev = pf->indio_dev; 124 struct ad7606_state *st = iio_priv(indio_dev); 125 int ret; 126 127 mutex_lock(&st->lock); 128 129 ret = ad7606_read_samples(st); 130 if (ret == 0) 131 iio_push_to_buffers_with_timestamp(indio_dev, st->data, 132 iio_get_time_ns(indio_dev)); 133 134 iio_trigger_notify_done(indio_dev->trig); 135 /* The rising edge of the CONVST signal starts a new conversion. */ 136 gpiod_set_value(st->gpio_convst, 1); 137 138 mutex_unlock(&st->lock); 139 140 return IRQ_HANDLED; 141} 142 143static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch) 144{ 145 struct ad7606_state *st = iio_priv(indio_dev); 146 int ret; 147 148 gpiod_set_value(st->gpio_convst, 1); 149 ret = wait_for_completion_timeout(&st->completion, 150 msecs_to_jiffies(1000)); 151 if (!ret) { 152 ret = -ETIMEDOUT; 153 goto error_ret; 154 } 155 156 ret = ad7606_read_samples(st); 157 if (ret == 0) 158 ret = st->data[ch]; 159 160error_ret: 161 gpiod_set_value(st->gpio_convst, 0); 162 163 return ret; 164} 165 166static int ad7606_read_raw(struct iio_dev *indio_dev, 167 struct iio_chan_spec const *chan, 168 int *val, 169 int *val2, 170 long m) 171{ 172 int ret, ch = 0; 173 struct ad7606_state *st = iio_priv(indio_dev); 174 175 switch (m) { 176 case IIO_CHAN_INFO_RAW: 177 ret = iio_device_claim_direct_mode(indio_dev); 178 if (ret) 179 return ret; 180 181 ret = ad7606_scan_direct(indio_dev, chan->address); 182 iio_device_release_direct_mode(indio_dev); 183 184 if (ret < 0) 185 return ret; 186 *val = (short)ret; 187 return IIO_VAL_INT; 188 case IIO_CHAN_INFO_SCALE: 189 if (st->sw_mode_en) 190 ch = chan->address; 191 *val = 0; 192 *val2 = st->scale_avail[st->range[ch]]; 193 return IIO_VAL_INT_PLUS_MICRO; 194 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 195 *val = st->oversampling; 196 return IIO_VAL_INT; 197 } 198 return -EINVAL; 199} 200 201static ssize_t ad7606_show_avail(char *buf, const unsigned int *vals, 202 unsigned int n, bool micros) 203{ 204 size_t len = 0; 205 int i; 206 207 for (i = 0; i < n; i++) { 208 len += scnprintf(buf + len, PAGE_SIZE - len, 209 micros ? "0.%06u " : "%u ", vals[i]); 210 } 211 buf[len - 1] = '\n'; 212 213 return len; 214} 215 216static ssize_t in_voltage_scale_available_show(struct device *dev, 217 struct device_attribute *attr, 218 char *buf) 219{ 220 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 221 struct ad7606_state *st = iio_priv(indio_dev); 222 223 return ad7606_show_avail(buf, st->scale_avail, st->num_scales, true); 224} 225 226static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0); 227 228static int ad7606_write_scale_hw(struct iio_dev *indio_dev, int ch, int val) 229{ 230 struct ad7606_state *st = iio_priv(indio_dev); 231 232 gpiod_set_value(st->gpio_range, val); 233 234 return 0; 235} 236 237static int ad7606_write_os_hw(struct iio_dev *indio_dev, int val) 238{ 239 struct ad7606_state *st = iio_priv(indio_dev); 240 DECLARE_BITMAP(values, 3); 241 242 values[0] = val; 243 244 gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc, 245 st->gpio_os->info, values); 246 247 /* AD7616 requires a reset to update value */ 248 if (st->chip_info->os_req_reset) 249 ad7606_reset(st); 250 251 return 0; 252} 253 254static int ad7606_write_raw(struct iio_dev *indio_dev, 255 struct iio_chan_spec const *chan, 256 int val, 257 int val2, 258 long mask) 259{ 260 struct ad7606_state *st = iio_priv(indio_dev); 261 int i, ret, ch = 0; 262 263 switch (mask) { 264 case IIO_CHAN_INFO_SCALE: 265 mutex_lock(&st->lock); 266 i = find_closest(val2, st->scale_avail, st->num_scales); 267 if (st->sw_mode_en) 268 ch = chan->address; 269 ret = st->write_scale(indio_dev, ch, i); 270 if (ret < 0) { 271 mutex_unlock(&st->lock); 272 return ret; 273 } 274 st->range[ch] = i; 275 mutex_unlock(&st->lock); 276 277 return 0; 278 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 279 if (val2) 280 return -EINVAL; 281 i = find_closest(val, st->oversampling_avail, 282 st->num_os_ratios); 283 mutex_lock(&st->lock); 284 ret = st->write_os(indio_dev, i); 285 if (ret < 0) { 286 mutex_unlock(&st->lock); 287 return ret; 288 } 289 st->oversampling = st->oversampling_avail[i]; 290 mutex_unlock(&st->lock); 291 292 return 0; 293 default: 294 return -EINVAL; 295 } 296} 297 298static ssize_t ad7606_oversampling_ratio_avail(struct device *dev, 299 struct device_attribute *attr, 300 char *buf) 301{ 302 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 303 struct ad7606_state *st = iio_priv(indio_dev); 304 305 return ad7606_show_avail(buf, st->oversampling_avail, 306 st->num_os_ratios, false); 307} 308 309static IIO_DEVICE_ATTR(oversampling_ratio_available, 0444, 310 ad7606_oversampling_ratio_avail, NULL, 0); 311 312static struct attribute *ad7606_attributes_os_and_range[] = { 313 &iio_dev_attr_in_voltage_scale_available.dev_attr.attr, 314 &iio_dev_attr_oversampling_ratio_available.dev_attr.attr, 315 NULL, 316}; 317 318static const struct attribute_group ad7606_attribute_group_os_and_range = { 319 .attrs = ad7606_attributes_os_and_range, 320}; 321 322static struct attribute *ad7606_attributes_os[] = { 323 &iio_dev_attr_oversampling_ratio_available.dev_attr.attr, 324 NULL, 325}; 326 327static const struct attribute_group ad7606_attribute_group_os = { 328 .attrs = ad7606_attributes_os, 329}; 330 331static struct attribute *ad7606_attributes_range[] = { 332 &iio_dev_attr_in_voltage_scale_available.dev_attr.attr, 333 NULL, 334}; 335 336static const struct attribute_group ad7606_attribute_group_range = { 337 .attrs = ad7606_attributes_range, 338}; 339 340static const struct iio_chan_spec ad7605_channels[] = { 341 IIO_CHAN_SOFT_TIMESTAMP(4), 342 AD7605_CHANNEL(0), 343 AD7605_CHANNEL(1), 344 AD7605_CHANNEL(2), 345 AD7605_CHANNEL(3), 346}; 347 348static const struct iio_chan_spec ad7606_channels[] = { 349 IIO_CHAN_SOFT_TIMESTAMP(8), 350 AD7606_CHANNEL(0), 351 AD7606_CHANNEL(1), 352 AD7606_CHANNEL(2), 353 AD7606_CHANNEL(3), 354 AD7606_CHANNEL(4), 355 AD7606_CHANNEL(5), 356 AD7606_CHANNEL(6), 357 AD7606_CHANNEL(7), 358}; 359 360/* 361 * The current assumption that this driver makes for AD7616, is that it's 362 * working in Hardware Mode with Serial, Burst and Sequencer modes activated. 363 * To activate them, following pins must be pulled high: 364 * -SER/PAR 365 * -SEQEN 366 * And following pins must be pulled low: 367 * -WR/BURST 368 * -DB4/SER1W 369 */ 370static const struct iio_chan_spec ad7616_channels[] = { 371 IIO_CHAN_SOFT_TIMESTAMP(16), 372 AD7606_CHANNEL(0), 373 AD7606_CHANNEL(1), 374 AD7606_CHANNEL(2), 375 AD7606_CHANNEL(3), 376 AD7606_CHANNEL(4), 377 AD7606_CHANNEL(5), 378 AD7606_CHANNEL(6), 379 AD7606_CHANNEL(7), 380 AD7606_CHANNEL(8), 381 AD7606_CHANNEL(9), 382 AD7606_CHANNEL(10), 383 AD7606_CHANNEL(11), 384 AD7606_CHANNEL(12), 385 AD7606_CHANNEL(13), 386 AD7606_CHANNEL(14), 387 AD7606_CHANNEL(15), 388}; 389 390static const struct ad7606_chip_info ad7606_chip_info_tbl[] = { 391 /* More devices added in future */ 392 [ID_AD7605_4] = { 393 .channels = ad7605_channels, 394 .num_channels = 5, 395 }, 396 [ID_AD7606_8] = { 397 .channels = ad7606_channels, 398 .num_channels = 9, 399 .oversampling_avail = ad7606_oversampling_avail, 400 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail), 401 }, 402 [ID_AD7606_6] = { 403 .channels = ad7606_channels, 404 .num_channels = 7, 405 .oversampling_avail = ad7606_oversampling_avail, 406 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail), 407 }, 408 [ID_AD7606_4] = { 409 .channels = ad7606_channels, 410 .num_channels = 5, 411 .oversampling_avail = ad7606_oversampling_avail, 412 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail), 413 }, 414 [ID_AD7606B] = { 415 .channels = ad7606_channels, 416 .num_channels = 9, 417 .oversampling_avail = ad7606_oversampling_avail, 418 .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail), 419 }, 420 [ID_AD7616] = { 421 .channels = ad7616_channels, 422 .num_channels = 17, 423 .oversampling_avail = ad7616_oversampling_avail, 424 .oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail), 425 .os_req_reset = true, 426 .init_delay_ms = 15, 427 }, 428}; 429 430static int ad7606_request_gpios(struct ad7606_state *st) 431{ 432 struct device *dev = st->dev; 433 434 st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start", 435 GPIOD_OUT_LOW); 436 if (IS_ERR(st->gpio_convst)) 437 return PTR_ERR(st->gpio_convst); 438 439 st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); 440 if (IS_ERR(st->gpio_reset)) 441 return PTR_ERR(st->gpio_reset); 442 443 st->gpio_range = devm_gpiod_get_optional(dev, "adi,range", 444 GPIOD_OUT_LOW); 445 if (IS_ERR(st->gpio_range)) 446 return PTR_ERR(st->gpio_range); 447 448 st->gpio_standby = devm_gpiod_get_optional(dev, "standby", 449 GPIOD_OUT_HIGH); 450 if (IS_ERR(st->gpio_standby)) 451 return PTR_ERR(st->gpio_standby); 452 453 st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data", 454 GPIOD_IN); 455 if (IS_ERR(st->gpio_frstdata)) 456 return PTR_ERR(st->gpio_frstdata); 457 458 if (!st->chip_info->oversampling_num) 459 return 0; 460 461 st->gpio_os = devm_gpiod_get_array_optional(dev, 462 "adi,oversampling-ratio", 463 GPIOD_OUT_LOW); 464 return PTR_ERR_OR_ZERO(st->gpio_os); 465} 466 467/* 468 * The BUSY signal indicates when conversions are in progress, so when a rising 469 * edge of CONVST is applied, BUSY goes logic high and transitions low at the 470 * end of the entire conversion process. The falling edge of the BUSY signal 471 * triggers this interrupt. 472 */ 473static irqreturn_t ad7606_interrupt(int irq, void *dev_id) 474{ 475 struct iio_dev *indio_dev = dev_id; 476 struct ad7606_state *st = iio_priv(indio_dev); 477 478 if (iio_buffer_enabled(indio_dev)) { 479 gpiod_set_value(st->gpio_convst, 0); 480 iio_trigger_poll_nested(st->trig); 481 } else { 482 complete(&st->completion); 483 } 484 485 return IRQ_HANDLED; 486}; 487 488static int ad7606_validate_trigger(struct iio_dev *indio_dev, 489 struct iio_trigger *trig) 490{ 491 struct ad7606_state *st = iio_priv(indio_dev); 492 493 if (st->trig != trig) 494 return -EINVAL; 495 496 return 0; 497} 498 499static int ad7606_buffer_postenable(struct iio_dev *indio_dev) 500{ 501 struct ad7606_state *st = iio_priv(indio_dev); 502 503 gpiod_set_value(st->gpio_convst, 1); 504 505 return 0; 506} 507 508static int ad7606_buffer_predisable(struct iio_dev *indio_dev) 509{ 510 struct ad7606_state *st = iio_priv(indio_dev); 511 512 gpiod_set_value(st->gpio_convst, 0); 513 514 return 0; 515} 516 517static const struct iio_buffer_setup_ops ad7606_buffer_ops = { 518 .postenable = &ad7606_buffer_postenable, 519 .predisable = &ad7606_buffer_predisable, 520}; 521 522static const struct iio_info ad7606_info_no_os_or_range = { 523 .read_raw = &ad7606_read_raw, 524 .validate_trigger = &ad7606_validate_trigger, 525}; 526 527static const struct iio_info ad7606_info_os_and_range = { 528 .read_raw = &ad7606_read_raw, 529 .write_raw = &ad7606_write_raw, 530 .attrs = &ad7606_attribute_group_os_and_range, 531 .validate_trigger = &ad7606_validate_trigger, 532}; 533 534static const struct iio_info ad7606_info_os_range_and_debug = { 535 .read_raw = &ad7606_read_raw, 536 .write_raw = &ad7606_write_raw, 537 .debugfs_reg_access = &ad7606_reg_access, 538 .attrs = &ad7606_attribute_group_os_and_range, 539 .validate_trigger = &ad7606_validate_trigger, 540}; 541 542static const struct iio_info ad7606_info_os = { 543 .read_raw = &ad7606_read_raw, 544 .write_raw = &ad7606_write_raw, 545 .attrs = &ad7606_attribute_group_os, 546 .validate_trigger = &ad7606_validate_trigger, 547}; 548 549static const struct iio_info ad7606_info_range = { 550 .read_raw = &ad7606_read_raw, 551 .write_raw = &ad7606_write_raw, 552 .attrs = &ad7606_attribute_group_range, 553 .validate_trigger = &ad7606_validate_trigger, 554}; 555 556static const struct iio_trigger_ops ad7606_trigger_ops = { 557 .validate_device = iio_trigger_validate_own_device, 558}; 559 560int ad7606_probe(struct device *dev, int irq, void __iomem *base_address, 561 const char *name, unsigned int id, 562 const struct ad7606_bus_ops *bops) 563{ 564 struct ad7606_state *st; 565 int ret; 566 struct iio_dev *indio_dev; 567 568 indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); 569 if (!indio_dev) 570 return -ENOMEM; 571 572 st = iio_priv(indio_dev); 573 dev_set_drvdata(dev, indio_dev); 574 575 st->dev = dev; 576 mutex_init(&st->lock); 577 st->bops = bops; 578 st->base_address = base_address; 579 /* tied to logic low, analog input range is +/- 5V */ 580 st->range[0] = 0; 581 st->oversampling = 1; 582 st->scale_avail = ad7606_scale_avail; 583 st->num_scales = ARRAY_SIZE(ad7606_scale_avail); 584 585 ret = devm_regulator_get_enable(dev, "avcc"); 586 if (ret) 587 return dev_err_probe(dev, ret, 588 "Failed to enable specified AVcc supply\n"); 589 590 st->chip_info = &ad7606_chip_info_tbl[id]; 591 592 if (st->chip_info->oversampling_num) { 593 st->oversampling_avail = st->chip_info->oversampling_avail; 594 st->num_os_ratios = st->chip_info->oversampling_num; 595 } 596 597 ret = ad7606_request_gpios(st); 598 if (ret) 599 return ret; 600 601 if (st->gpio_os) { 602 if (st->gpio_range) 603 indio_dev->info = &ad7606_info_os_and_range; 604 else 605 indio_dev->info = &ad7606_info_os; 606 } else { 607 if (st->gpio_range) 608 indio_dev->info = &ad7606_info_range; 609 else 610 indio_dev->info = &ad7606_info_no_os_or_range; 611 } 612 indio_dev->modes = INDIO_DIRECT_MODE; 613 indio_dev->name = name; 614 indio_dev->channels = st->chip_info->channels; 615 indio_dev->num_channels = st->chip_info->num_channels; 616 617 init_completion(&st->completion); 618 619 ret = ad7606_reset(st); 620 if (ret) 621 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n"); 622 623 /* AD7616 requires al least 15ms to reconfigure after a reset */ 624 if (st->chip_info->init_delay_ms) { 625 if (msleep_interruptible(st->chip_info->init_delay_ms)) 626 return -ERESTARTSYS; 627 } 628 629 st->write_scale = ad7606_write_scale_hw; 630 st->write_os = ad7606_write_os_hw; 631 632 if (st->bops->sw_mode_config) 633 st->sw_mode_en = device_property_present(st->dev, 634 "adi,sw-mode"); 635 636 if (st->sw_mode_en) { 637 /* Scale of 0.076293 is only available in sw mode */ 638 st->scale_avail = ad7616_sw_scale_avail; 639 st->num_scales = ARRAY_SIZE(ad7616_sw_scale_avail); 640 641 /* After reset, in software mode, ��10 V is set by default */ 642 memset32(st->range, 2, ARRAY_SIZE(st->range)); 643 indio_dev->info = &ad7606_info_os_range_and_debug; 644 645 ret = st->bops->sw_mode_config(indio_dev); 646 if (ret < 0) 647 return ret; 648 } 649 650 st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", 651 indio_dev->name, 652 iio_device_id(indio_dev)); 653 if (!st->trig) 654 return -ENOMEM; 655 656 st->trig->ops = &ad7606_trigger_ops; 657 iio_trigger_set_drvdata(st->trig, indio_dev); 658 ret = devm_iio_trigger_register(dev, st->trig); 659 if (ret) 660 return ret; 661 662 indio_dev->trig = iio_trigger_get(st->trig); 663 664 ret = devm_request_threaded_irq(dev, irq, 665 NULL, 666 &ad7606_interrupt, 667 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 668 name, indio_dev); 669 if (ret) 670 return ret; 671 672 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 673 &iio_pollfunc_store_time, 674 &ad7606_trigger_handler, 675 &ad7606_buffer_ops); 676 if (ret) 677 return ret; 678 679 return devm_iio_device_register(dev, indio_dev); 680} 681EXPORT_SYMBOL_NS_GPL(ad7606_probe, IIO_AD7606); 682 683#ifdef CONFIG_PM_SLEEP 684 685static int ad7606_suspend(struct device *dev) 686{ 687 struct iio_dev *indio_dev = dev_get_drvdata(dev); 688 struct ad7606_state *st = iio_priv(indio_dev); 689 690 if (st->gpio_standby) { 691 gpiod_set_value(st->gpio_range, 1); 692 gpiod_set_value(st->gpio_standby, 0); 693 } 694 695 return 0; 696} 697 698static int ad7606_resume(struct device *dev) 699{ 700 struct iio_dev *indio_dev = dev_get_drvdata(dev); 701 struct ad7606_state *st = iio_priv(indio_dev); 702 703 if (st->gpio_standby) { 704 gpiod_set_value(st->gpio_range, st->range[0]); 705 gpiod_set_value(st->gpio_standby, 1); 706 ad7606_reset(st); 707 } 708 709 return 0; 710} 711 712SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume); 713EXPORT_SYMBOL_NS_GPL(ad7606_pm_ops, IIO_AD7606); 714 715#endif 716 717MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); 718MODULE_DESCRIPTION("Analog Devices AD7606 ADC"); 719MODULE_LICENSE("GPL v2"); 720