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