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