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; 65 struct list_head *pos, *tmp; 66 67 mutex_lock(&iio_map_list_lock); 68 list_for_each_safe(pos, tmp, &iio_map_list) { 69 mapi = list_entry(pos, struct iio_map_internal, l); 70 if (indio_dev == mapi->indio_dev) { 71 list_del(&mapi->l); 72 kfree(mapi); 73 ret = 0; 74 } 75 } 76 mutex_unlock(&iio_map_list_lock); 77 return ret; 78 } 79 EXPORT_SYMBOL_GPL(iio_map_array_unregister); 80 81 static const struct iio_chan_spec 82 *iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name) 83 { 84 int i; 85 const struct iio_chan_spec *chan = NULL; 86 87 for (i = 0; i < indio_dev->num_channels; i++) 88 if (indio_dev->channels[i].datasheet_name && 89 strcmp(name, indio_dev->channels[i].datasheet_name) == 0) { 90 chan = &indio_dev->channels[i]; 91 break; 92 } 93 return chan; 94 } 95 96 #ifdef CONFIG_OF 97 98 static int iio_dev_node_match(struct device *dev, void *data) 99 { 100 return dev->of_node == data && dev->type == &iio_device_type; 101 } 102 103 /** 104 * __of_iio_simple_xlate - translate iiospec to the IIO channel index 105 * @indio_dev: pointer to the iio_dev structure 106 * @iiospec: IIO specifier as found in the device tree 107 * 108 * This is simple translation function, suitable for the most 1:1 mapped 109 * channels in IIO chips. This function performs only one sanity check: 110 * whether IIO index is less than num_channels (that is specified in the 111 * iio_dev). 112 */ 113 static int __of_iio_simple_xlate(struct iio_dev *indio_dev, 114 const struct of_phandle_args *iiospec) 115 { 116 if (!iiospec->args_count) 117 return 0; 118 119 if (iiospec->args[0] >= indio_dev->num_channels) { 120 dev_err(&indio_dev->dev, "invalid channel index %u\n", 121 iiospec->args[0]); 122 return -EINVAL; 123 } 124 125 return iiospec->args[0]; 126 } 127 128 static int __of_iio_channel_get(struct iio_channel *channel, 129 struct device_node *np, int index) 130 { 131 struct device *idev; 132 struct iio_dev *indio_dev; 133 int err; 134 struct of_phandle_args iiospec; 135 136 err = of_parse_phandle_with_args(np, "io-channels", 137 "#io-channel-cells", 138 index, &iiospec); 139 if (err) 140 return err; 141 142 idev = bus_find_device(&iio_bus_type, NULL, iiospec.np, 143 iio_dev_node_match); 144 of_node_put(iiospec.np); 145 if (idev == NULL) 146 return -EPROBE_DEFER; 147 148 indio_dev = dev_to_iio_dev(idev); 149 channel->indio_dev = indio_dev; 150 if (indio_dev->info->of_xlate) 151 index = indio_dev->info->of_xlate(indio_dev, &iiospec); 152 else 153 index = __of_iio_simple_xlate(indio_dev, &iiospec); 154 if (index < 0) 155 goto err_put; 156 channel->channel = &indio_dev->channels[index]; 157 158 return 0; 159 160 err_put: 161 iio_device_put(indio_dev); 162 return index; 163 } 164 165 static struct iio_channel *of_iio_channel_get(struct device_node *np, int index) 166 { 167 struct iio_channel *channel; 168 int err; 169 170 if (index < 0) 171 return ERR_PTR(-EINVAL); 172 173 channel = kzalloc(sizeof(*channel), GFP_KERNEL); 174 if (channel == NULL) 175 return ERR_PTR(-ENOMEM); 176 177 err = __of_iio_channel_get(channel, np, index); 178 if (err) 179 goto err_free_channel; 180 181 return channel; 182 183 err_free_channel: 184 kfree(channel); 185 return ERR_PTR(err); 186 } 187 188 static struct iio_channel *of_iio_channel_get_by_name(struct device_node *np, 189 const char *name) 190 { 191 struct iio_channel *chan = NULL; 192 193 /* Walk up the tree of devices looking for a matching iio channel */ 194 while (np) { 195 int index = 0; 196 197 /* 198 * For named iio channels, first look up the name in the 199 * "io-channel-names" property. If it cannot be found, the 200 * index will be an error code, and of_iio_channel_get() 201 * will fail. 202 */ 203 if (name) 204 index = of_property_match_string(np, "io-channel-names", 205 name); 206 chan = of_iio_channel_get(np, index); 207 if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER) 208 break; 209 else if (name && index >= 0) { 210 pr_err("ERROR: could not get IIO channel %s:%s(%i)\n", 211 np->full_name, name ? name : "", index); 212 return NULL; 213 } 214 215 /* 216 * No matching IIO channel found on this node. 217 * If the parent node has a "io-channel-ranges" property, 218 * then we can try one of its channels. 219 */ 220 np = np->parent; 221 if (np && !of_get_property(np, "io-channel-ranges", NULL)) 222 return NULL; 223 } 224 225 return chan; 226 } 227 228 static struct iio_channel *of_iio_channel_get_all(struct device *dev) 229 { 230 struct iio_channel *chans; 231 int i, mapind, nummaps = 0; 232 int ret; 233 234 do { 235 ret = of_parse_phandle_with_args(dev->of_node, 236 "io-channels", 237 "#io-channel-cells", 238 nummaps, NULL); 239 if (ret < 0) 240 break; 241 } while (++nummaps); 242 243 if (nummaps == 0) /* no error, return NULL to search map table */ 244 return NULL; 245 246 /* NULL terminated array to save passing size */ 247 chans = kcalloc(nummaps + 1, sizeof(*chans), GFP_KERNEL); 248 if (chans == NULL) 249 return ERR_PTR(-ENOMEM); 250 251 /* Search for OF matches */ 252 for (mapind = 0; mapind < nummaps; mapind++) { 253 ret = __of_iio_channel_get(&chans[mapind], dev->of_node, 254 mapind); 255 if (ret) 256 goto error_free_chans; 257 } 258 return chans; 259 260 error_free_chans: 261 for (i = 0; i < mapind; i++) 262 iio_device_put(chans[i].indio_dev); 263 kfree(chans); 264 return ERR_PTR(ret); 265 } 266 267 #else /* CONFIG_OF */ 268 269 static inline struct iio_channel * 270 of_iio_channel_get_by_name(struct device_node *np, const char *name) 271 { 272 return NULL; 273 } 274 275 static inline struct iio_channel *of_iio_channel_get_all(struct device *dev) 276 { 277 return NULL; 278 } 279 280 #endif /* CONFIG_OF */ 281 282 static struct iio_channel *iio_channel_get_sys(const char *name, 283 const char *channel_name) 284 { 285 struct iio_map_internal *c_i = NULL, *c = NULL; 286 struct iio_channel *channel; 287 int err; 288 289 if (name == NULL && channel_name == NULL) 290 return ERR_PTR(-ENODEV); 291 292 /* first find matching entry the channel map */ 293 mutex_lock(&iio_map_list_lock); 294 list_for_each_entry(c_i, &iio_map_list, l) { 295 if ((name && strcmp(name, c_i->map->consumer_dev_name) != 0) || 296 (channel_name && 297 strcmp(channel_name, c_i->map->consumer_channel) != 0)) 298 continue; 299 c = c_i; 300 iio_device_get(c->indio_dev); 301 break; 302 } 303 mutex_unlock(&iio_map_list_lock); 304 if (c == NULL) 305 return ERR_PTR(-ENODEV); 306 307 channel = kzalloc(sizeof(*channel), GFP_KERNEL); 308 if (channel == NULL) { 309 err = -ENOMEM; 310 goto error_no_mem; 311 } 312 313 channel->indio_dev = c->indio_dev; 314 315 if (c->map->adc_channel_label) { 316 channel->channel = 317 iio_chan_spec_from_name(channel->indio_dev, 318 c->map->adc_channel_label); 319 320 if (channel->channel == NULL) { 321 err = -EINVAL; 322 goto error_no_chan; 323 } 324 } 325 326 return channel; 327 328 error_no_chan: 329 kfree(channel); 330 error_no_mem: 331 iio_device_put(c->indio_dev); 332 return ERR_PTR(err); 333 } 334 335 struct iio_channel *iio_channel_get(struct device *dev, 336 const char *channel_name) 337 { 338 const char *name = dev ? dev_name(dev) : NULL; 339 struct iio_channel *channel; 340 341 if (dev) { 342 channel = of_iio_channel_get_by_name(dev->of_node, 343 channel_name); 344 if (channel != NULL) 345 return channel; 346 } 347 348 return iio_channel_get_sys(name, channel_name); 349 } 350 EXPORT_SYMBOL_GPL(iio_channel_get); 351 352 void iio_channel_release(struct iio_channel *channel) 353 { 354 iio_device_put(channel->indio_dev); 355 kfree(channel); 356 } 357 EXPORT_SYMBOL_GPL(iio_channel_release); 358 359 struct iio_channel *iio_channel_get_all(struct device *dev) 360 { 361 const char *name; 362 struct iio_channel *chans; 363 struct iio_map_internal *c = NULL; 364 int nummaps = 0; 365 int mapind = 0; 366 int i, ret; 367 368 if (dev == NULL) 369 return ERR_PTR(-EINVAL); 370 371 chans = of_iio_channel_get_all(dev); 372 if (chans) 373 return chans; 374 375 name = dev_name(dev); 376 377 mutex_lock(&iio_map_list_lock); 378 /* first count the matching maps */ 379 list_for_each_entry(c, &iio_map_list, l) 380 if (name && strcmp(name, c->map->consumer_dev_name) != 0) 381 continue; 382 else 383 nummaps++; 384 385 if (nummaps == 0) { 386 ret = -ENODEV; 387 goto error_ret; 388 } 389 390 /* NULL terminated array to save passing size */ 391 chans = kzalloc(sizeof(*chans)*(nummaps + 1), GFP_KERNEL); 392 if (chans == NULL) { 393 ret = -ENOMEM; 394 goto error_ret; 395 } 396 397 /* for each map fill in the chans element */ 398 list_for_each_entry(c, &iio_map_list, l) { 399 if (name && strcmp(name, c->map->consumer_dev_name) != 0) 400 continue; 401 chans[mapind].indio_dev = c->indio_dev; 402 chans[mapind].data = c->map->consumer_data; 403 chans[mapind].channel = 404 iio_chan_spec_from_name(chans[mapind].indio_dev, 405 c->map->adc_channel_label); 406 if (chans[mapind].channel == NULL) { 407 ret = -EINVAL; 408 goto error_free_chans; 409 } 410 iio_device_get(chans[mapind].indio_dev); 411 mapind++; 412 } 413 if (mapind == 0) { 414 ret = -ENODEV; 415 goto error_free_chans; 416 } 417 mutex_unlock(&iio_map_list_lock); 418 419 return chans; 420 421 error_free_chans: 422 for (i = 0; i < nummaps; i++) 423 iio_device_put(chans[i].indio_dev); 424 kfree(chans); 425 error_ret: 426 mutex_unlock(&iio_map_list_lock); 427 428 return ERR_PTR(ret); 429 } 430 EXPORT_SYMBOL_GPL(iio_channel_get_all); 431 432 void iio_channel_release_all(struct iio_channel *channels) 433 { 434 struct iio_channel *chan = &channels[0]; 435 436 while (chan->indio_dev) { 437 iio_device_put(chan->indio_dev); 438 chan++; 439 } 440 kfree(channels); 441 } 442 EXPORT_SYMBOL_GPL(iio_channel_release_all); 443 444 static int iio_channel_read(struct iio_channel *chan, int *val, int *val2, 445 enum iio_chan_info_enum info) 446 { 447 int unused; 448 int vals[INDIO_MAX_RAW_ELEMENTS]; 449 int ret; 450 int val_len = 2; 451 452 if (val2 == NULL) 453 val2 = &unused; 454 455 if(!iio_channel_has_info(chan->channel, info)) 456 return -EINVAL; 457 458 if (chan->indio_dev->info->read_raw_multi) { 459 ret = chan->indio_dev->info->read_raw_multi(chan->indio_dev, 460 chan->channel, INDIO_MAX_RAW_ELEMENTS, 461 vals, &val_len, info); 462 *val = vals[0]; 463 *val2 = vals[1]; 464 } else 465 ret = chan->indio_dev->info->read_raw(chan->indio_dev, 466 chan->channel, val, val2, info); 467 468 return ret; 469 } 470 471 int iio_read_channel_raw(struct iio_channel *chan, int *val) 472 { 473 int ret; 474 475 mutex_lock(&chan->indio_dev->info_exist_lock); 476 if (chan->indio_dev->info == NULL) { 477 ret = -ENODEV; 478 goto err_unlock; 479 } 480 481 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW); 482 err_unlock: 483 mutex_unlock(&chan->indio_dev->info_exist_lock); 484 485 return ret; 486 } 487 EXPORT_SYMBOL_GPL(iio_read_channel_raw); 488 489 int iio_read_channel_average_raw(struct iio_channel *chan, int *val) 490 { 491 int ret; 492 493 mutex_lock(&chan->indio_dev->info_exist_lock); 494 if (chan->indio_dev->info == NULL) { 495 ret = -ENODEV; 496 goto err_unlock; 497 } 498 499 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_AVERAGE_RAW); 500 err_unlock: 501 mutex_unlock(&chan->indio_dev->info_exist_lock); 502 503 return ret; 504 } 505 EXPORT_SYMBOL_GPL(iio_read_channel_average_raw); 506 507 static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan, 508 int raw, int *processed, unsigned int scale) 509 { 510 int scale_type, scale_val, scale_val2, offset; 511 s64 raw64 = raw; 512 int ret; 513 514 ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_OFFSET); 515 if (ret >= 0) 516 raw64 += offset; 517 518 scale_type = iio_channel_read(chan, &scale_val, &scale_val2, 519 IIO_CHAN_INFO_SCALE); 520 if (scale_type < 0) 521 return scale_type; 522 523 switch (scale_type) { 524 case IIO_VAL_INT: 525 *processed = raw64 * scale_val; 526 break; 527 case IIO_VAL_INT_PLUS_MICRO: 528 if (scale_val2 < 0) 529 *processed = -raw64 * scale_val; 530 else 531 *processed = raw64 * scale_val; 532 *processed += div_s64(raw64 * (s64)scale_val2 * scale, 533 1000000LL); 534 break; 535 case IIO_VAL_INT_PLUS_NANO: 536 if (scale_val2 < 0) 537 *processed = -raw64 * scale_val; 538 else 539 *processed = raw64 * scale_val; 540 *processed += div_s64(raw64 * (s64)scale_val2 * scale, 541 1000000000LL); 542 break; 543 case IIO_VAL_FRACTIONAL: 544 *processed = div_s64(raw64 * (s64)scale_val * scale, 545 scale_val2); 546 break; 547 case IIO_VAL_FRACTIONAL_LOG2: 548 *processed = (raw64 * (s64)scale_val * scale) >> scale_val2; 549 break; 550 default: 551 return -EINVAL; 552 } 553 554 return 0; 555 } 556 557 int iio_convert_raw_to_processed(struct iio_channel *chan, int raw, 558 int *processed, unsigned int scale) 559 { 560 int ret; 561 562 mutex_lock(&chan->indio_dev->info_exist_lock); 563 if (chan->indio_dev->info == NULL) { 564 ret = -ENODEV; 565 goto err_unlock; 566 } 567 568 ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed, 569 scale); 570 err_unlock: 571 mutex_unlock(&chan->indio_dev->info_exist_lock); 572 573 return ret; 574 } 575 EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed); 576 577 int iio_read_channel_processed(struct iio_channel *chan, int *val) 578 { 579 int ret; 580 581 mutex_lock(&chan->indio_dev->info_exist_lock); 582 if (chan->indio_dev->info == NULL) { 583 ret = -ENODEV; 584 goto err_unlock; 585 } 586 587 if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) { 588 ret = iio_channel_read(chan, val, NULL, 589 IIO_CHAN_INFO_PROCESSED); 590 } else { 591 ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW); 592 if (ret < 0) 593 goto err_unlock; 594 ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1); 595 } 596 597 err_unlock: 598 mutex_unlock(&chan->indio_dev->info_exist_lock); 599 600 return ret; 601 } 602 EXPORT_SYMBOL_GPL(iio_read_channel_processed); 603 604 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2) 605 { 606 int ret; 607 608 mutex_lock(&chan->indio_dev->info_exist_lock); 609 if (chan->indio_dev->info == NULL) { 610 ret = -ENODEV; 611 goto err_unlock; 612 } 613 614 ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE); 615 err_unlock: 616 mutex_unlock(&chan->indio_dev->info_exist_lock); 617 618 return ret; 619 } 620 EXPORT_SYMBOL_GPL(iio_read_channel_scale); 621 622 int iio_get_channel_type(struct iio_channel *chan, enum iio_chan_type *type) 623 { 624 int ret = 0; 625 /* Need to verify underlying driver has not gone away */ 626 627 mutex_lock(&chan->indio_dev->info_exist_lock); 628 if (chan->indio_dev->info == NULL) { 629 ret = -ENODEV; 630 goto err_unlock; 631 } 632 633 *type = chan->channel->type; 634 err_unlock: 635 mutex_unlock(&chan->indio_dev->info_exist_lock); 636 637 return ret; 638 } 639 EXPORT_SYMBOL_GPL(iio_get_channel_type); 640 641 static int iio_channel_write(struct iio_channel *chan, int val, int val2, 642 enum iio_chan_info_enum info) 643 { 644 return chan->indio_dev->info->write_raw(chan->indio_dev, 645 chan->channel, val, val2, info); 646 } 647 648 int iio_write_channel_raw(struct iio_channel *chan, int val) 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_channel_write(chan, val, 0, IIO_CHAN_INFO_RAW); 659 err_unlock: 660 mutex_unlock(&chan->indio_dev->info_exist_lock); 661 662 return ret; 663 } 664 EXPORT_SYMBOL_GPL(iio_write_channel_raw); 665