1 /* The industrial I/O core in kernel channel mapping 2 * 3 * Copyright (c) 2011 Jonathan Cameron 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 as published by 7 * the Free Software Foundation. 8 */ 9 #include <linux/err.h> 10 #include <linux/export.h> 11 #include <linux/slab.h> 12 #include <linux/mutex.h> 13 #include <linux/of.h> 14 15 #include <linux/iio/iio.h> 16 #include "iio_core.h" 17 #include <linux/iio/machine.h> 18 #include <linux/iio/driver.h> 19 #include <linux/iio/consumer.h> 20 21 struct iio_map_internal { 22 struct iio_dev *indio_dev; 23 struct iio_map *map; 24 struct list_head l; 25 }; 26 27 static LIST_HEAD(iio_map_list); 28 static DEFINE_MUTEX(iio_map_list_lock); 29 30 int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps) 31 { 32 int i = 0, ret = 0; 33 struct iio_map_internal *mapi; 34 35 if (maps == NULL) 36 return 0; 37 38 mutex_lock(&iio_map_list_lock); 39 while (maps[i].consumer_dev_name != NULL) { 40 mapi = kzalloc(sizeof(*mapi), GFP_KERNEL); 41 if (mapi == NULL) { 42 ret = -ENOMEM; 43 goto error_ret; 44 } 45 mapi->map = &maps[i]; 46 mapi->indio_dev = indio_dev; 47 list_add(&mapi->l, &iio_map_list); 48 i++; 49 } 50 error_ret: 51 mutex_unlock(&iio_map_list_lock); 52 53 return ret; 54 } 55 EXPORT_SYMBOL_GPL(iio_map_array_register); 56 57 58 /* 59 * Remove all map entries associated with the given iio device 60 */ 61 int iio_map_array_unregister(struct iio_dev *indio_dev) 62 { 63 int ret = -ENODEV; 64 struct iio_map_internal *mapi, *next; 65 66 mutex_lock(&iio_map_list_lock); 67 list_for_each_entry_safe(mapi, next, &iio_map_list, l) { 68 if (indio_dev == mapi->indio_dev) { 69 list_del(&mapi->l); 70 kfree(mapi); 71 ret = 0; 72 } 73 } 74 mutex_unlock(&iio_map_list_lock); 75 return ret; 76 } 77 EXPORT_SYMBOL_GPL(iio_map_array_unregister); 78 79 static const struct iio_chan_spec 80 *iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name) 81 { 82 int i; 83 const struct iio_chan_spec *chan = NULL; 84 85 for (i = 0; i < indio_dev->num_channels; i++) 86 if (indio_dev->channels[i].datasheet_name && 87 strcmp(name, indio_dev->channels[i].datasheet_name) == 0) { 88 chan = &indio_dev->channels[i]; 89 break; 90 } 91 return chan; 92 } 93 94 #ifdef CONFIG_OF 95 96 static int iio_dev_node_match(struct device *dev, void *data) 97 { 98 return dev->of_node == data && dev->type == &iio_device_type; 99 } 100 101 /** 102 * __of_iio_simple_xlate - translate iiospec to the IIO channel index 103 * @indio_dev: pointer to the iio_dev structure 104 * @iiospec: IIO specifier as found in the device tree 105 * 106 * This is simple translation function, suitable for the most 1:1 mapped 107 * channels in IIO chips. This function performs only one sanity check: 108 * whether IIO index is less than num_channels (that is specified in the 109 * iio_dev). 110 */ 111 static int __of_iio_simple_xlate(struct iio_dev *indio_dev, 112 const struct of_phandle_args *iiospec) 113 { 114 if (!iiospec->args_count) 115 return 0; 116 117 if (iiospec->args[0] >= indio_dev->num_channels) { 118 dev_err(&indio_dev->dev, "invalid channel index %u\n", 119 iiospec->args[0]); 120 return -EINVAL; 121 } 122 123 return iiospec->args[0]; 124 } 125 126 static int __of_iio_channel_get(struct iio_channel *channel, 127 struct device_node *np, int index) 128 { 129 struct device *idev; 130 struct iio_dev *indio_dev; 131 int err; 132 struct of_phandle_args iiospec; 133 134 err = of_parse_phandle_with_args(np, "io-channels", 135 "#io-channel-cells", 136 index, &iiospec); 137 if (err) 138 return err; 139 140 idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, 141 iio_dev_node_match); 142 of_node_put(iiospec.np); 143 if (idev == NULL) 144 return -EPROBE_DEFER; 145 146 indio_dev = dev_to_iio_dev(idev); 147 channel->indio_dev = indio_dev; 148 if (indio_dev->info->of_xlate) 149 index = indio_dev->info->of_xlate(indio_dev, &iiospec); 150 else 151 index = __of_iio_simple_xlate(indio_dev, &iiospec); 152 if (index < 0) 153 goto err_put; 154 channel->channel = &indio_dev->channels[index]; 155 156 return 0; 157 158 err_put: 159 iio_device_put(indio_dev); 160 return index; 161 } 162 163 static struct iio_channel *of_iio_channel_get(struct device_node *np, int index) 164 { 165 struct iio_channel *channel; 166 int err; 167 168 if (index < 0) 169 return ERR_PTR(-EINVAL); 170 171 channel = kzalloc(sizeof(*channel), GFP_KERNEL); 172 if (channel == NULL) 173 return ERR_PTR(-ENOMEM); 174 175 err = __of_iio_channel_get(channel, np, index); 176 if (err) 177 goto err_free_channel; 178 179 return channel; 180 181 err_free_channel: 182 kfree(channel); 183 return ERR_PTR(err); 184 } 185 186 static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np, 187 const char *name) 188 { 189 struct iio_channel *chan = NULL; 190 191 /* Walk up the tree of devices looking for a matching iio channel */ 192 while (np) { 193 int index = 0; 194 195 /* 196 * For named iio channels, first look up the name in the 197 * "io-channel-names" property. If it cannot be found, the 198 * index will be an error code, and of_iio_channel_get() 199 * will fail. 200 */ 201 if (name) 202 index = of_property_match_string(np, "io-channel-names", 203 name); 204 chan = of_iio_channel_get(np, index); 205 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER) 206 break; 207 else if (name && index >= 0) { 208 pr_err("ERROR: could not get IIO channel %s:%s(%i)\n", 209 np->full_name, name ? name : "", index); 210 return NULL; 211 } 212 213 /* 214 * No matching IIO channel found on this node. 215 * If the parent node has a "io-channel-ranges" property, 216 * then we can try one of its channels. 217 */ 218 np = np->parent; 219 if (np && !of_get_property(np, "io-channel-ranges", NULL)) 220 return NULL; 221 } 222 223 return chan; 224 } 225 226 static struct iio_channel *of_iio_channel_get_all(struct device *dev) 227 { 228 struct iio_channel *chans; 229 int i, mapind, nummaps = 0; 230 int ret; 231 232 do { 233 ret = of_parse_phandle_with_args(dev->of_node, 234 "io-channels", 235 "#io-channel-cells", 236 nummaps, NULL); 237 if (ret < 0) 238 break; 239 } while (++nummaps); 240 241 if (nummaps == 0) /* no error, return NULL to search map table */ 242 return NULL; 243 244 /* NULL terminated array to save passing size */ 245 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL); 246 if (chans == NULL) 247 return ERR_PTR(-ENOMEM); 248 249 /* Search for OF matches */ 250 for (mapind = 0; mapind < nummaps; mapind++) { 251 ret = __of_iio_channel_get(&chans[mapind], dev->of_node, 252 mapind); 253 if (ret) 254 goto error_free_chans; 255 } 256 return chans; 257 258 error_free_chans: 259 for (i = 0; i < mapind; i++) 260 iio_device_put(chans[i].indio_dev); 261 kfree(chans); 262 return ERR_PTR(ret); 263 } 264 265 #else /* CONFIG_OF */ 266 267 static inline struct iio_channel * 268 of_iio_channel_get_by_name(struct device_node *np, const char *name) 269 { 270 return NULL; 271 } 272 273 static inline struct iio_channel *of_iio_channel_get_all(struct device *dev) 274 { 275 return NULL; 276 } 277 278 #endif /* CONFIG_OF */ 279 280 static struct iio_channel *iio_channel_get_sys(const char *name, 281 const char *channel_name) 282 { 283 struct iio_map_internal *c_i = NULL, *c = NULL; 284 struct iio_channel *channel; 285 int err; 286 287 if (name == NULL && channel_name == NULL) 288 return ERR_PTR(-ENODEV); 289 290 /* first find matching entry the channel map */ 291 mutex_lock(&iio_map_list_lock); 292 list_for_each_entry(c_i, &iio_map_list, l) { 293 if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) || 294 (channel_name && 295 strcmp(channel_name, c_i->map->consumer_channel) != 0)) 296 continue; 297 c = c_i; 298 iio_device_get(c->indio_dev); 299 break; 300 } 301 mutex_unlock(&iio_map_list_lock); 302 if (c == NULL) 303 return ERR_PTR(-ENODEV); 304 305 channel = kzalloc(sizeof(*channel), GFP_KERNEL); 306 if (channel == NULL) { 307 err = -ENOMEM; 308 goto error_no_mem; 309 } 310 311 channel->indio_dev = c->indio_dev; 312 313 if (c->map->adc_channel_label) { 314 channel->channel = 315 iio_chan_spec_from_name(channel->indio_dev, 316 c->map->adc_channel_label); 317 318 if (channel->channel == NULL) { 319 err = -EINVAL; 320 goto error_no_chan; 321 } 322 } 323 324 return channel; 325 326 error_no_chan: 327 kfree(channel); 328 error_no_mem: 329 iio_device_put(c->indio_dev); 330 return ERR_PTR(err); 331 } 332 333 struct iio_channel *iio_channel_get(struct device *dev, 334 const char *channel_name) 335 { 336 const char *name = dev ? dev_name(dev) : NULL; 337 struct iio_channel *channel; 338 339 if (dev) { 340 channel = of_iio_channel_get_by_name(dev->of_node, 341 channel_name); 342 if (channel != NULL) 343 return channel; 344 } 345 346 return iio_channel_get_sys(name, channel_name); 347 } 348 EXPORT_SYMBOL_GPL(iio_channel_get); 349 350 void iio_channel_release(struct iio_channel *channel) 351 { 352 if (!channel) 353 return; 354 iio_device_put(channel->indio_dev); 355 kfree(channel); 356 } 357 EXPORT_SYMBOL_GPL(iio_channel_release); 358 359 static void devm_iio_channel_free(struct device *dev, void *res) 360 { 361 struct iio_channel *channel = *(struct iio_channel **)res; 362 363 iio_channel_release(channel); 364 } 365 366 static int devm_iio_channel_match(struct device *dev, void *res, void *data) 367 { 368 struct iio_channel **r = res; 369 370 if (!r || !*r) { 371 WARN_ON(!r || !*r); 372 return 0; 373 } 374 375 return *r == data; 376 } 377 378 struct iio_channel *devm_iio_channel_get(struct device *dev, 379 const char *channel_name) 380 { 381 struct iio_channel **ptr, *channel; 382 383 ptr = devres_alloc(devm_iio_channel_free, sizeof(*ptr), GFP_KERNEL); 384 if (!ptr) 385 return ERR_PTR(-ENOMEM); 386 387 channel = iio_channel_get(dev, channel_name); 388 if (IS_ERR(channel)) { 389 devres_free(ptr); 390 return channel; 391 } 392 393 *ptr = channel; 394 devres_add(dev, ptr); 395 396 return channel; 397 } 398 EXPORT_SYMBOL_GPL(devm_iio_channel_get); 399 400 void devm_iio_channel_release(struct device *dev, struct iio_channel *channel) 401 { 402 WARN_ON(devres_release(dev, devm_iio_channel_free, 403 devm_iio_channel_match, channel)); 404 } 405 EXPORT_SYMBOL_GPL(devm_iio_channel_release); 406 407 struct iio_channel *iio_channel_get_all(struct device *dev) 408 { 409 const char *name; 410 struct iio_channel *chans; 411 struct iio_map_internal *c = NULL; 412 int nummaps = 0; 413 int mapind = 0; 414 int i, ret; 415 416 if (dev == NULL) 417 return ERR_PTR(-EINVAL); 418 419 chans = of_iio_channel_get_all(dev); 420 if (chans) 421 return chans; 422 423 name = dev_name(dev); 424 425 mutex_lock(&iio_map_list_lock); 426 /* first count the matching maps */ 427 list_for_each_entry(c, &iio_map_list, l) 428 if (name && strcmp(name, c->map->consumer_dev_name) != 0) 429 continue; 430 else 431 nummaps++; 432 433 if (nummaps == 0) { 434 ret = -ENODEV; 435 goto error_ret; 436 } 437 438 /* NULL terminated array to save passing size */ 439 chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL); 440 if (chans == NULL) { 441 ret = -ENOMEM; 442 goto error_ret; 443 } 444 445 /* for each map fill in the chans element */ 446 list_for_each_entry(c, &iio_map_list, l) { 447 if (name && strcmp(name, c->map->consumer_dev_name) != 0) 448 continue; 449 chans[mapind].indio_dev = c->indio_dev; 450 chans[mapind].data = c->map->consumer_data; 451 chans[mapind].channel = 452 iio_chan_spec_from_name(chans[mapind].indio_dev, 453 c->map->adc_channel_label); 454 if (chans[mapind].channel == NULL) { 455 ret = -EINVAL; 456 goto error_free_chans; 457 } 458 iio_device_get(chans[mapind].indio_dev); 459 mapind++; 460 } 461 if (mapind == 0) { 462 ret = -ENODEV; 463 goto error_free_chans; 464 } 465 mutex_unlock(&iio_map_list_lock); 466 467 return chans; 468 469 error_free_chans: 470 for (i = 0; i < nummaps; i++) 471 iio_device_put(chans[i].indio_dev); 472 kfree(chans); 473 error_ret: 474 mutex_unlock(&iio_map_list_lock); 475 476 return ERR_PTR(ret); 477 } 478 EXPORT_SYMBOL_GPL(iio_channel_get_all); 479 480 void iio_channel_release_all(struct iio_channel *channels) 481 { 482 struct iio_channel *chan = &channels[0]; 483 484 while (chan->indio_dev) { 485 iio_device_put(chan->indio_dev); 486 chan++; 487 } 488 kfree(channels); 489 } 490 EXPORT_SYMBOL_GPL(iio_channel_release_all); 491 492 static void devm_iio_channel_free_all(struct device *dev, void *res) 493 { 494 struct iio_channel *channels = *(struct iio_channel **)res; 495 496 iio_channel_release_all(channels); 497 } 498 499 struct iio_channel *devm_iio_channel_get_all(struct device *dev) 500 { 501 struct iio_channel **ptr, *channels; 502 503 ptr = devres_alloc(devm_iio_channel_free_all, sizeof(*ptr), GFP_KERNEL); 504 if (!ptr) 505 return ERR_PTR(-ENOMEM); 506 507 channels = iio_channel_get_all(dev); 508 if (IS_ERR(channels)) { 509 devres_free(ptr); 510 return channels; 511 } 512 513 *ptr = channels; 514 devres_add(dev, ptr); 515 516 return channels; 517 } 518 EXPORT_SYMBOL_GPL(devm_iio_channel_get_all); 519 520 void devm_iio_channel_release_all(struct device *dev, 521 struct iio_channel *channels) 522 { 523 WARN_ON(devres_release(dev, devm_iio_channel_free_all, 524 devm_iio_channel_match, channels)); 525 } 526 EXPORT_SYMBOL_GPL(devm_iio_channel_release_all); 527 528 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2, 529 enum iio_chan_info_enum info) 530 { 531 int unused; 532 int vals[INDIO_MAX_RAW_ELEMENTS]; 533 int ret; 534 int val_len = 2; 535 536 if (val2 == NULL) 537 val2 = &unused; 538 539 if (!iio_channel_has_info(chan->channel, info)) 540 return -EINVAL; 541 542 if (chan->indio_dev->info->read_raw_multi) { 543 ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev, 544 chan->channel, INDIO_MAX_RAW_ELEMENTS, 545 vals, &val_len, info); 546 *val = vals[0]; 547 *val2 = vals[1]; 548 } else 549 ret = chan->indio_dev->info->read_raw(chan->indio_dev, 550 chan->channel, val, val2, info); 551 552 return ret; 553 } 554 555 int iio_read_channel_raw(struct iio_channel *chan, int *val) 556 { 557 int ret; 558 559 mutex_lock(&chan->indio_dev->info_exist_lock); 560 if (chan->indio_dev->info == NULL) { 561 ret = -ENODEV; 562 goto err_unlock; 563 } 564 565 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW); 566 err_unlock: 567 mutex_unlock(&chan->indio_dev->info_exist_lock); 568 569 return ret; 570 } 571 EXPORT_SYMBOL_GPL(iio_read_channel_raw); 572 573 int iio_read_channel_average_raw(struct iio_channel *chan, int *val) 574 { 575 int ret; 576 577 mutex_lock(&chan->indio_dev->info_exist_lock); 578 if (chan->indio_dev->info == NULL) { 579 ret = -ENODEV; 580 goto err_unlock; 581 } 582 583 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW); 584 err_unlock: 585 mutex_unlock(&chan->indio_dev->info_exist_lock); 586 587 return ret; 588 } 589 EXPORT_SYMBOL_GPL(iio_read_channel_average_raw); 590 591 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan, 592 int raw, int *processed, unsigned int scale) 593 { 594 int scale_type, scale_val, scale_val2, offset; 595 s64 raw64 = raw; 596 int ret; 597 598 ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET); 599 if (ret >= 0) 600 raw64 += offset; 601 602 scale_type = iio_channel_read(chan, &scale_val, &scale_val2, 603 IIO_CHAN_INFO_SCALE); 604 if (scale_type < 0) { 605 /* 606 * Just pass raw values as processed if no scaling is 607 * available. 608 */ 609 *processed = raw; 610 return 0; 611 } 612 613 switch (scale_type) { 614 case IIO_VAL_INT: 615 *processed = raw64 * scale_val; 616 break; 617 case IIO_VAL_INT_PLUS_MICRO: 618 if (scale_val2 < 0) 619 *processed = -raw64 * scale_val; 620 else 621 *processed = raw64 * scale_val; 622 *processed += div_s64(raw64 * (s64)scale_val2 * scale, 623 1000000LL); 624 break; 625 case IIO_VAL_INT_PLUS_NANO: 626 if (scale_val2 < 0) 627 *processed = -raw64 * scale_val; 628 else 629 *processed = raw64 * scale_val; 630 *processed += div_s64(raw64 * (s64)scale_val2 * scale, 631 1000000000LL); 632 break; 633 case IIO_VAL_FRACTIONAL: 634 *processed = div_s64(raw64 * (s64)scale_val * scale, 635 scale_val2); 636 break; 637 case IIO_VAL_FRACTIONAL_LOG2: 638 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2; 639 break; 640 default: 641 return -EINVAL; 642 } 643 644 return 0; 645 } 646 647 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, 648 int *processed, unsigned int scale) 649 { 650 int ret; 651 652 mutex_lock(&chan->indio_dev->info_exist_lock); 653 if (chan->indio_dev->info == NULL) { 654 ret = -ENODEV; 655 goto err_unlock; 656 } 657 658 ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed, 659 scale); 660 err_unlock: 661 mutex_unlock(&chan->indio_dev->info_exist_lock); 662 663 return ret; 664 } 665 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed); 666 667 static int iio_read_channel_attribute(struct iio_channel *chan, 668 int *val, int *val2, 669 enum iio_chan_info_enum attribute) 670 { 671 int ret; 672 673 mutex_lock(&chan->indio_dev->info_exist_lock); 674 if (chan->indio_dev->info == NULL) { 675 ret = -ENODEV; 676 goto err_unlock; 677 } 678 679 ret = iio_channel_read(chan, val, val2, attribute); 680 err_unlock: 681 mutex_unlock(&chan->indio_dev->info_exist_lock); 682 683 return ret; 684 } 685 686 int iio_read_channel_offset(struct iio_channel *chan, int *val, int *val2) 687 { 688 return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_OFFSET); 689 } 690 EXPORT_SYMBOL_GPL(iio_read_channel_offset); 691 692 int iio_read_channel_processed(struct iio_channel *chan, int *val) 693 { 694 int ret; 695 696 mutex_lock(&chan->indio_dev->info_exist_lock); 697 if (chan->indio_dev->info == NULL) { 698 ret = -ENODEV; 699 goto err_unlock; 700 } 701 702 if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) { 703 ret = iio_channel_read(chan, val, NULL, 704 IIO_CHAN_INFO_PROCESSED); 705 } else { 706 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW); 707 if (ret < 0) 708 goto err_unlock; 709 ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1); 710 } 711 712 err_unlock: 713 mutex_unlock(&chan->indio_dev->info_exist_lock); 714 715 return ret; 716 } 717 EXPORT_SYMBOL_GPL(iio_read_channel_processed); 718 719 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2) 720 { 721 return iio_read_channel_attribute(chan, val, val2, IIO_CHAN_INFO_SCALE); 722 } 723 EXPORT_SYMBOL_GPL(iio_read_channel_scale); 724 725 static int iio_channel_read_avail(struct iio_channel *chan, 726 const int **vals, int *type, int *length, 727 enum iio_chan_info_enum info) 728 { 729 if (!iio_channel_has_available(chan->channel, info)) 730 return -EINVAL; 731 732 return chan->indio_dev->info->read_avail(chan->indio_dev, chan->channel, 733 vals, type, length, info); 734 } 735 736 int iio_read_avail_channel_raw(struct iio_channel *chan, 737 const int **vals, int *length) 738 { 739 int ret; 740 int type; 741 742 mutex_lock(&chan->indio_dev->info_exist_lock); 743 if (!chan->indio_dev->info) { 744 ret = -ENODEV; 745 goto err_unlock; 746 } 747 748 ret = iio_channel_read_avail(chan, 749 vals, &type, length, IIO_CHAN_INFO_RAW); 750 err_unlock: 751 mutex_unlock(&chan->indio_dev->info_exist_lock); 752 753 if (ret >= 0 && type != IIO_VAL_INT) { 754 /* raw values are assumed to be IIO_VAL_INT */ 755 ret = -EINVAL; 756 goto err_unlock; 757 } 758 759 return ret; 760 } 761 EXPORT_SYMBOL_GPL(iio_read_avail_channel_raw); 762 763 static int iio_channel_read_max(struct iio_channel *chan, 764 int *val, int *val2, int *type, 765 enum iio_chan_info_enum info) 766 { 767 int unused; 768 const int *vals; 769 int length; 770 int ret; 771 772 if (!val2) 773 val2 = &unused; 774 775 ret = iio_channel_read_avail(chan, &vals, type, &length, info); 776 switch (ret) { 777 case IIO_AVAIL_RANGE: 778 switch (*type) { 779 case IIO_VAL_INT: 780 *val = vals[2]; 781 break; 782 default: 783 *val = vals[4]; 784 *val2 = vals[5]; 785 } 786 return 0; 787 788 case IIO_AVAIL_LIST: 789 if (length <= 0) 790 return -EINVAL; 791 switch (*type) { 792 case IIO_VAL_INT: 793 *val = vals[--length]; 794 while (length) { 795 if (vals[--length] > *val) 796 *val = vals[length]; 797 } 798 break; 799 default: 800 /* FIXME: learn about max for other iio values */ 801 return -EINVAL; 802 } 803 return 0; 804 805 default: 806 return ret; 807 } 808 } 809 810 int iio_read_max_channel_raw(struct iio_channel *chan, int *val) 811 { 812 int ret; 813 int type; 814 815 mutex_lock(&chan->indio_dev->info_exist_lock); 816 if (!chan->indio_dev->info) { 817 ret = -ENODEV; 818 goto err_unlock; 819 } 820 821 ret = iio_channel_read_max(chan, val, NULL, &type, IIO_CHAN_INFO_RAW); 822 err_unlock: 823 mutex_unlock(&chan->indio_dev->info_exist_lock); 824 825 return ret; 826 } 827 EXPORT_SYMBOL_GPL(iio_read_max_channel_raw); 828 829 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type) 830 { 831 int ret = 0; 832 /* Need to verify underlying driver has not gone away */ 833 834 mutex_lock(&chan->indio_dev->info_exist_lock); 835 if (chan->indio_dev->info == NULL) { 836 ret = -ENODEV; 837 goto err_unlock; 838 } 839 840 *type = chan->channel->type; 841 err_unlock: 842 mutex_unlock(&chan->indio_dev->info_exist_lock); 843 844 return ret; 845 } 846 EXPORT_SYMBOL_GPL(iio_get_channel_type); 847 848 static int iio_channel_write(struct iio_channel *chan, int val, int val2, 849 enum iio_chan_info_enum info) 850 { 851 return chan->indio_dev->info->write_raw(chan->indio_dev, 852 chan->channel, val, val2, info); 853 } 854 855 int iio_write_channel_raw(struct iio_channel *chan, int val) 856 { 857 int ret; 858 859 mutex_lock(&chan->indio_dev->info_exist_lock); 860 if (chan->indio_dev->info == NULL) { 861 ret = -ENODEV; 862 goto err_unlock; 863 } 864 865 ret = iio_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW); 866 err_unlock: 867 mutex_unlock(&chan->indio_dev->info_exist_lock); 868 869 return ret; 870 } 871 EXPORT_SYMBOL_GPL(iio_write_channel_raw); 872 873 unsigned int iio_get_channel_ext_info_count(struct iio_channel *chan) 874 { 875 const struct iio_chan_spec_ext_info *ext_info; 876 unsigned int i = 0; 877 878 if (!chan->channel->ext_info) 879 return i; 880 881 for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++) 882 ++i; 883 884 return i; 885 } 886 EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count); 887 888 static const struct iio_chan_spec_ext_info *iio_lookup_ext_info( 889 const struct iio_channel *chan, 890 const char *attr) 891 { 892 const struct iio_chan_spec_ext_info *ext_info; 893 894 if (!chan->channel->ext_info) 895 return NULL; 896 897 for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) { 898 if (!strcmp(attr, ext_info->name)) 899 return ext_info; 900 } 901 902 return NULL; 903 } 904 905 ssize_t iio_read_channel_ext_info(struct iio_channel *chan, 906 const char *attr, char *buf) 907 { 908 const struct iio_chan_spec_ext_info *ext_info; 909 910 ext_info = iio_lookup_ext_info(chan, attr); 911 if (!ext_info) 912 return -EINVAL; 913 914 return ext_info->read(chan->indio_dev, ext_info->private, 915 chan->channel, buf); 916 } 917 EXPORT_SYMBOL_GPL(iio_read_channel_ext_info); 918 919 ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr, 920 const char *buf, size_t len) 921 { 922 const struct iio_chan_spec_ext_info *ext_info; 923 924 ext_info = iio_lookup_ext_info(chan, attr); 925 if (!ext_info) 926 return -EINVAL; 927 928 return ext_info->write(chan->indio_dev, ext_info->private, 929 chan->channel, buf, len); 930 } 931 EXPORT_SYMBOL_GPL(iio_write_channel_ext_info); 932