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 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