1 /* The industrial I/O core 2 * 3 * Copyright (c) 2008 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 * Based on elements of hwmon and input subsystems. 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/idr.h> 15 #include <linux/kdev_t.h> 16 #include <linux/err.h> 17 #include <linux/device.h> 18 #include <linux/fs.h> 19 #include <linux/poll.h> 20 #include <linux/sched.h> 21 #include <linux/wait.h> 22 #include <linux/cdev.h> 23 #include <linux/slab.h> 24 #include <linux/anon_inodes.h> 25 #include <linux/debugfs.h> 26 #include <linux/iio/iio.h> 27 #include "iio_core.h" 28 #include "iio_core_trigger.h" 29 #include <linux/iio/sysfs.h> 30 #include <linux/iio/events.h> 31 32 /* IDA to assign each registered device a unique id */ 33 static DEFINE_IDA(iio_ida); 34 35 static dev_t iio_devt; 36 37 #define IIO_DEV_MAX 256 38 struct bus_type iio_bus_type = { 39 .name = "iio", 40 }; 41 EXPORT_SYMBOL(iio_bus_type); 42 43 static struct dentry *iio_debugfs_dentry; 44 45 static const char * const iio_direction[] = { 46 [0] = "in", 47 [1] = "out", 48 }; 49 50 static const char * const iio_chan_type_name_spec[] = { 51 [IIO_VOLTAGE] = "voltage", 52 [IIO_CURRENT] = "current", 53 [IIO_POWER] = "power", 54 [IIO_ACCEL] = "accel", 55 [IIO_ANGL_VEL] = "anglvel", 56 [IIO_MAGN] = "magn", 57 [IIO_LIGHT] = "illuminance", 58 [IIO_INTENSITY] = "intensity", 59 [IIO_PROXIMITY] = "proximity", 60 [IIO_TEMP] = "temp", 61 [IIO_INCLI] = "incli", 62 [IIO_ROT] = "rot", 63 [IIO_ANGL] = "angl", 64 [IIO_TIMESTAMP] = "timestamp", 65 [IIO_CAPACITANCE] = "capacitance", 66 [IIO_ALTVOLTAGE] = "altvoltage", 67 [IIO_CCT] = "cct", 68 [IIO_PRESSURE] = "pressure", 69 }; 70 71 static const char * const iio_modifier_names[] = { 72 [IIO_MOD_X] = "x", 73 [IIO_MOD_Y] = "y", 74 [IIO_MOD_Z] = "z", 75 [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)", 76 [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2", 77 [IIO_MOD_LIGHT_BOTH] = "both", 78 [IIO_MOD_LIGHT_IR] = "ir", 79 [IIO_MOD_LIGHT_CLEAR] = "clear", 80 [IIO_MOD_LIGHT_RED] = "red", 81 [IIO_MOD_LIGHT_GREEN] = "green", 82 [IIO_MOD_LIGHT_BLUE] = "blue", 83 }; 84 85 /* relies on pairs of these shared then separate */ 86 static const char * const iio_chan_info_postfix[] = { 87 [IIO_CHAN_INFO_RAW] = "raw", 88 [IIO_CHAN_INFO_PROCESSED] = "input", 89 [IIO_CHAN_INFO_SCALE] = "scale", 90 [IIO_CHAN_INFO_OFFSET] = "offset", 91 [IIO_CHAN_INFO_CALIBSCALE] = "calibscale", 92 [IIO_CHAN_INFO_CALIBBIAS] = "calibbias", 93 [IIO_CHAN_INFO_PEAK] = "peak_raw", 94 [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale", 95 [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw", 96 [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw", 97 [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY] 98 = "filter_low_pass_3db_frequency", 99 [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency", 100 [IIO_CHAN_INFO_FREQUENCY] = "frequency", 101 [IIO_CHAN_INFO_PHASE] = "phase", 102 [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain", 103 [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis", 104 }; 105 106 const struct iio_chan_spec 107 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si) 108 { 109 int i; 110 111 for (i = 0; i < indio_dev->num_channels; i++) 112 if (indio_dev->channels[i].scan_index == si) 113 return &indio_dev->channels[i]; 114 return NULL; 115 } 116 117 /* This turns up an awful lot */ 118 ssize_t iio_read_const_attr(struct device *dev, 119 struct device_attribute *attr, 120 char *buf) 121 { 122 return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string); 123 } 124 EXPORT_SYMBOL(iio_read_const_attr); 125 126 static int __init iio_init(void) 127 { 128 int ret; 129 130 /* Register sysfs bus */ 131 ret = bus_register(&iio_bus_type); 132 if (ret < 0) { 133 printk(KERN_ERR 134 "%s could not register bus type\n", 135 __FILE__); 136 goto error_nothing; 137 } 138 139 ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio"); 140 if (ret < 0) { 141 printk(KERN_ERR "%s: failed to allocate char dev region\n", 142 __FILE__); 143 goto error_unregister_bus_type; 144 } 145 146 iio_debugfs_dentry = debugfs_create_dir("iio", NULL); 147 148 return 0; 149 150 error_unregister_bus_type: 151 bus_unregister(&iio_bus_type); 152 error_nothing: 153 return ret; 154 } 155 156 static void __exit iio_exit(void) 157 { 158 if (iio_devt) 159 unregister_chrdev_region(iio_devt, IIO_DEV_MAX); 160 bus_unregister(&iio_bus_type); 161 debugfs_remove(iio_debugfs_dentry); 162 } 163 164 #if defined(CONFIG_DEBUG_FS) 165 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf, 166 size_t count, loff_t *ppos) 167 { 168 struct iio_dev *indio_dev = file->private_data; 169 char buf[20]; 170 unsigned val = 0; 171 ssize_t len; 172 int ret; 173 174 ret = indio_dev->info->debugfs_reg_access(indio_dev, 175 indio_dev->cached_reg_addr, 176 0, &val); 177 if (ret) 178 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__); 179 180 len = snprintf(buf, sizeof(buf), "0x%X\n", val); 181 182 return simple_read_from_buffer(userbuf, count, ppos, buf, len); 183 } 184 185 static ssize_t iio_debugfs_write_reg(struct file *file, 186 const char __user *userbuf, size_t count, loff_t *ppos) 187 { 188 struct iio_dev *indio_dev = file->private_data; 189 unsigned reg, val; 190 char buf[80]; 191 int ret; 192 193 count = min_t(size_t, count, (sizeof(buf)-1)); 194 if (copy_from_user(buf, userbuf, count)) 195 return -EFAULT; 196 197 buf[count] = 0; 198 199 ret = sscanf(buf, "%i %i", ®, &val); 200 201 switch (ret) { 202 case 1: 203 indio_dev->cached_reg_addr = reg; 204 break; 205 case 2: 206 indio_dev->cached_reg_addr = reg; 207 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg, 208 val, NULL); 209 if (ret) { 210 dev_err(indio_dev->dev.parent, "%s: write failed\n", 211 __func__); 212 return ret; 213 } 214 break; 215 default: 216 return -EINVAL; 217 } 218 219 return count; 220 } 221 222 static const struct file_operations iio_debugfs_reg_fops = { 223 .open = simple_open, 224 .read = iio_debugfs_read_reg, 225 .write = iio_debugfs_write_reg, 226 }; 227 228 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) 229 { 230 debugfs_remove_recursive(indio_dev->debugfs_dentry); 231 } 232 233 static int iio_device_register_debugfs(struct iio_dev *indio_dev) 234 { 235 struct dentry *d; 236 237 if (indio_dev->info->debugfs_reg_access == NULL) 238 return 0; 239 240 if (!iio_debugfs_dentry) 241 return 0; 242 243 indio_dev->debugfs_dentry = 244 debugfs_create_dir(dev_name(&indio_dev->dev), 245 iio_debugfs_dentry); 246 if (indio_dev->debugfs_dentry == NULL) { 247 dev_warn(indio_dev->dev.parent, 248 "Failed to create debugfs directory\n"); 249 return -EFAULT; 250 } 251 252 d = debugfs_create_file("direct_reg_access", 0644, 253 indio_dev->debugfs_dentry, 254 indio_dev, &iio_debugfs_reg_fops); 255 if (!d) { 256 iio_device_unregister_debugfs(indio_dev); 257 return -ENOMEM; 258 } 259 260 return 0; 261 } 262 #else 263 static int iio_device_register_debugfs(struct iio_dev *indio_dev) 264 { 265 return 0; 266 } 267 268 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) 269 { 270 } 271 #endif /* CONFIG_DEBUG_FS */ 272 273 static ssize_t iio_read_channel_ext_info(struct device *dev, 274 struct device_attribute *attr, 275 char *buf) 276 { 277 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 278 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 279 const struct iio_chan_spec_ext_info *ext_info; 280 281 ext_info = &this_attr->c->ext_info[this_attr->address]; 282 283 return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf); 284 } 285 286 static ssize_t iio_write_channel_ext_info(struct device *dev, 287 struct device_attribute *attr, 288 const char *buf, 289 size_t len) 290 { 291 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 292 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 293 const struct iio_chan_spec_ext_info *ext_info; 294 295 ext_info = &this_attr->c->ext_info[this_attr->address]; 296 297 return ext_info->write(indio_dev, ext_info->private, 298 this_attr->c, buf, len); 299 } 300 301 ssize_t iio_enum_available_read(struct iio_dev *indio_dev, 302 uintptr_t priv, const struct iio_chan_spec *chan, char *buf) 303 { 304 const struct iio_enum *e = (const struct iio_enum *)priv; 305 unsigned int i; 306 size_t len = 0; 307 308 if (!e->num_items) 309 return 0; 310 311 for (i = 0; i < e->num_items; ++i) 312 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]); 313 314 /* replace last space with a newline */ 315 buf[len - 1] = '\n'; 316 317 return len; 318 } 319 EXPORT_SYMBOL_GPL(iio_enum_available_read); 320 321 ssize_t iio_enum_read(struct iio_dev *indio_dev, 322 uintptr_t priv, const struct iio_chan_spec *chan, char *buf) 323 { 324 const struct iio_enum *e = (const struct iio_enum *)priv; 325 int i; 326 327 if (!e->get) 328 return -EINVAL; 329 330 i = e->get(indio_dev, chan); 331 if (i < 0) 332 return i; 333 else if (i >= e->num_items) 334 return -EINVAL; 335 336 return sprintf(buf, "%s\n", e->items[i]); 337 } 338 EXPORT_SYMBOL_GPL(iio_enum_read); 339 340 ssize_t iio_enum_write(struct iio_dev *indio_dev, 341 uintptr_t priv, const struct iio_chan_spec *chan, const char *buf, 342 size_t len) 343 { 344 const struct iio_enum *e = (const struct iio_enum *)priv; 345 unsigned int i; 346 int ret; 347 348 if (!e->set) 349 return -EINVAL; 350 351 for (i = 0; i < e->num_items; i++) { 352 if (sysfs_streq(buf, e->items[i])) 353 break; 354 } 355 356 if (i == e->num_items) 357 return -EINVAL; 358 359 ret = e->set(indio_dev, chan, i); 360 return ret ? ret : len; 361 } 362 EXPORT_SYMBOL_GPL(iio_enum_write); 363 364 static ssize_t iio_read_channel_info(struct device *dev, 365 struct device_attribute *attr, 366 char *buf) 367 { 368 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 369 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 370 unsigned long long tmp; 371 int val, val2; 372 bool scale_db = false; 373 int ret = indio_dev->info->read_raw(indio_dev, this_attr->c, 374 &val, &val2, this_attr->address); 375 376 if (ret < 0) 377 return ret; 378 379 switch (ret) { 380 case IIO_VAL_INT: 381 return sprintf(buf, "%d\n", val); 382 case IIO_VAL_INT_PLUS_MICRO_DB: 383 scale_db = true; 384 case IIO_VAL_INT_PLUS_MICRO: 385 if (val2 < 0) 386 return sprintf(buf, "-%d.%06u%s\n", val, -val2, 387 scale_db ? " dB" : ""); 388 else 389 return sprintf(buf, "%d.%06u%s\n", val, val2, 390 scale_db ? " dB" : ""); 391 case IIO_VAL_INT_PLUS_NANO: 392 if (val2 < 0) 393 return sprintf(buf, "-%d.%09u\n", val, -val2); 394 else 395 return sprintf(buf, "%d.%09u\n", val, val2); 396 case IIO_VAL_FRACTIONAL: 397 tmp = div_s64((s64)val * 1000000000LL, val2); 398 val2 = do_div(tmp, 1000000000LL); 399 val = tmp; 400 return sprintf(buf, "%d.%09u\n", val, val2); 401 case IIO_VAL_FRACTIONAL_LOG2: 402 tmp = (s64)val * 1000000000LL >> val2; 403 val2 = do_div(tmp, 1000000000LL); 404 val = tmp; 405 return sprintf(buf, "%d.%09u\n", val, val2); 406 default: 407 return 0; 408 } 409 } 410 411 /** 412 * iio_str_to_fixpoint() - Parse a fixed-point number from a string 413 * @str: The string to parse 414 * @fract_mult: Multiplier for the first decimal place, should be a power of 10 415 * @integer: The integer part of the number 416 * @fract: The fractional part of the number 417 * 418 * Returns 0 on success, or a negative error code if the string could not be 419 * parsed. 420 */ 421 int iio_str_to_fixpoint(const char *str, int fract_mult, 422 int *integer, int *fract) 423 { 424 int i = 0, f = 0; 425 bool integer_part = true, negative = false; 426 427 if (str[0] == '-') { 428 negative = true; 429 str++; 430 } else if (str[0] == '+') { 431 str++; 432 } 433 434 while (*str) { 435 if ('0' <= *str && *str <= '9') { 436 if (integer_part) { 437 i = i * 10 + *str - '0'; 438 } else { 439 f += fract_mult * (*str - '0'); 440 fract_mult /= 10; 441 } 442 } else if (*str == '\n') { 443 if (*(str + 1) == '\0') 444 break; 445 else 446 return -EINVAL; 447 } else if (*str == '.' && integer_part) { 448 integer_part = false; 449 } else { 450 return -EINVAL; 451 } 452 str++; 453 } 454 455 if (negative) { 456 if (i) 457 i = -i; 458 else 459 f = -f; 460 } 461 462 *integer = i; 463 *fract = f; 464 465 return 0; 466 } 467 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint); 468 469 static ssize_t iio_write_channel_info(struct device *dev, 470 struct device_attribute *attr, 471 const char *buf, 472 size_t len) 473 { 474 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 475 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 476 int ret, fract_mult = 100000; 477 int integer, fract; 478 479 /* Assumes decimal - precision based on number of digits */ 480 if (!indio_dev->info->write_raw) 481 return -EINVAL; 482 483 if (indio_dev->info->write_raw_get_fmt) 484 switch (indio_dev->info->write_raw_get_fmt(indio_dev, 485 this_attr->c, this_attr->address)) { 486 case IIO_VAL_INT_PLUS_MICRO: 487 fract_mult = 100000; 488 break; 489 case IIO_VAL_INT_PLUS_NANO: 490 fract_mult = 100000000; 491 break; 492 default: 493 return -EINVAL; 494 } 495 496 ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract); 497 if (ret) 498 return ret; 499 500 ret = indio_dev->info->write_raw(indio_dev, this_attr->c, 501 integer, fract, this_attr->address); 502 if (ret) 503 return ret; 504 505 return len; 506 } 507 508 static 509 int __iio_device_attr_init(struct device_attribute *dev_attr, 510 const char *postfix, 511 struct iio_chan_spec const *chan, 512 ssize_t (*readfunc)(struct device *dev, 513 struct device_attribute *attr, 514 char *buf), 515 ssize_t (*writefunc)(struct device *dev, 516 struct device_attribute *attr, 517 const char *buf, 518 size_t len), 519 bool generic) 520 { 521 int ret; 522 char *name_format, *full_postfix; 523 sysfs_attr_init(&dev_attr->attr); 524 525 /* Build up postfix of <extend_name>_<modifier>_postfix */ 526 if (chan->modified && !generic) { 527 if (chan->extend_name) 528 full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s", 529 iio_modifier_names[chan 530 ->channel2], 531 chan->extend_name, 532 postfix); 533 else 534 full_postfix = kasprintf(GFP_KERNEL, "%s_%s", 535 iio_modifier_names[chan 536 ->channel2], 537 postfix); 538 } else { 539 if (chan->extend_name == NULL) 540 full_postfix = kstrdup(postfix, GFP_KERNEL); 541 else 542 full_postfix = kasprintf(GFP_KERNEL, 543 "%s_%s", 544 chan->extend_name, 545 postfix); 546 } 547 if (full_postfix == NULL) { 548 ret = -ENOMEM; 549 goto error_ret; 550 } 551 552 if (chan->differential) { /* Differential can not have modifier */ 553 if (generic) 554 name_format 555 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s", 556 iio_direction[chan->output], 557 iio_chan_type_name_spec[chan->type], 558 iio_chan_type_name_spec[chan->type], 559 full_postfix); 560 else if (chan->indexed) 561 name_format 562 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s", 563 iio_direction[chan->output], 564 iio_chan_type_name_spec[chan->type], 565 chan->channel, 566 iio_chan_type_name_spec[chan->type], 567 chan->channel2, 568 full_postfix); 569 else { 570 WARN_ON("Differential channels must be indexed\n"); 571 ret = -EINVAL; 572 goto error_free_full_postfix; 573 } 574 } else { /* Single ended */ 575 if (generic) 576 name_format 577 = kasprintf(GFP_KERNEL, "%s_%s_%s", 578 iio_direction[chan->output], 579 iio_chan_type_name_spec[chan->type], 580 full_postfix); 581 else if (chan->indexed) 582 name_format 583 = kasprintf(GFP_KERNEL, "%s_%s%d_%s", 584 iio_direction[chan->output], 585 iio_chan_type_name_spec[chan->type], 586 chan->channel, 587 full_postfix); 588 else 589 name_format 590 = kasprintf(GFP_KERNEL, "%s_%s_%s", 591 iio_direction[chan->output], 592 iio_chan_type_name_spec[chan->type], 593 full_postfix); 594 } 595 if (name_format == NULL) { 596 ret = -ENOMEM; 597 goto error_free_full_postfix; 598 } 599 dev_attr->attr.name = kasprintf(GFP_KERNEL, 600 name_format, 601 chan->channel, 602 chan->channel2); 603 if (dev_attr->attr.name == NULL) { 604 ret = -ENOMEM; 605 goto error_free_name_format; 606 } 607 608 if (readfunc) { 609 dev_attr->attr.mode |= S_IRUGO; 610 dev_attr->show = readfunc; 611 } 612 613 if (writefunc) { 614 dev_attr->attr.mode |= S_IWUSR; 615 dev_attr->store = writefunc; 616 } 617 kfree(name_format); 618 kfree(full_postfix); 619 620 return 0; 621 622 error_free_name_format: 623 kfree(name_format); 624 error_free_full_postfix: 625 kfree(full_postfix); 626 error_ret: 627 return ret; 628 } 629 630 static void __iio_device_attr_deinit(struct device_attribute *dev_attr) 631 { 632 kfree(dev_attr->attr.name); 633 } 634 635 int __iio_add_chan_devattr(const char *postfix, 636 struct iio_chan_spec const *chan, 637 ssize_t (*readfunc)(struct device *dev, 638 struct device_attribute *attr, 639 char *buf), 640 ssize_t (*writefunc)(struct device *dev, 641 struct device_attribute *attr, 642 const char *buf, 643 size_t len), 644 u64 mask, 645 bool generic, 646 struct device *dev, 647 struct list_head *attr_list) 648 { 649 int ret; 650 struct iio_dev_attr *iio_attr, *t; 651 652 iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL); 653 if (iio_attr == NULL) { 654 ret = -ENOMEM; 655 goto error_ret; 656 } 657 ret = __iio_device_attr_init(&iio_attr->dev_attr, 658 postfix, chan, 659 readfunc, writefunc, generic); 660 if (ret) 661 goto error_iio_dev_attr_free; 662 iio_attr->c = chan; 663 iio_attr->address = mask; 664 list_for_each_entry(t, attr_list, l) 665 if (strcmp(t->dev_attr.attr.name, 666 iio_attr->dev_attr.attr.name) == 0) { 667 if (!generic) 668 dev_err(dev, "tried to double register : %s\n", 669 t->dev_attr.attr.name); 670 ret = -EBUSY; 671 goto error_device_attr_deinit; 672 } 673 list_add(&iio_attr->l, attr_list); 674 675 return 0; 676 677 error_device_attr_deinit: 678 __iio_device_attr_deinit(&iio_attr->dev_attr); 679 error_iio_dev_attr_free: 680 kfree(iio_attr); 681 error_ret: 682 return ret; 683 } 684 685 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev, 686 struct iio_chan_spec const *chan) 687 { 688 int ret, attrcount = 0; 689 int i; 690 const struct iio_chan_spec_ext_info *ext_info; 691 692 if (chan->channel < 0) 693 return 0; 694 for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) { 695 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2], 696 chan, 697 &iio_read_channel_info, 698 &iio_write_channel_info, 699 i/2, 700 !(i%2), 701 &indio_dev->dev, 702 &indio_dev->channel_attr_list); 703 if (ret == -EBUSY && (i%2 == 0)) { 704 ret = 0; 705 continue; 706 } 707 if (ret < 0) 708 goto error_ret; 709 attrcount++; 710 } 711 712 if (chan->ext_info) { 713 unsigned int i = 0; 714 for (ext_info = chan->ext_info; ext_info->name; ext_info++) { 715 ret = __iio_add_chan_devattr(ext_info->name, 716 chan, 717 ext_info->read ? 718 &iio_read_channel_ext_info : NULL, 719 ext_info->write ? 720 &iio_write_channel_ext_info : NULL, 721 i, 722 ext_info->shared, 723 &indio_dev->dev, 724 &indio_dev->channel_attr_list); 725 i++; 726 if (ret == -EBUSY && ext_info->shared) 727 continue; 728 729 if (ret) 730 goto error_ret; 731 732 attrcount++; 733 } 734 } 735 736 ret = attrcount; 737 error_ret: 738 return ret; 739 } 740 741 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev, 742 struct iio_dev_attr *p) 743 { 744 kfree(p->dev_attr.attr.name); 745 kfree(p); 746 } 747 748 static ssize_t iio_show_dev_name(struct device *dev, 749 struct device_attribute *attr, 750 char *buf) 751 { 752 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 753 return sprintf(buf, "%s\n", indio_dev->name); 754 } 755 756 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL); 757 758 static int iio_device_register_sysfs(struct iio_dev *indio_dev) 759 { 760 int i, ret = 0, attrcount, attrn, attrcount_orig = 0; 761 struct iio_dev_attr *p, *n; 762 struct attribute **attr; 763 764 /* First count elements in any existing group */ 765 if (indio_dev->info->attrs) { 766 attr = indio_dev->info->attrs->attrs; 767 while (*attr++ != NULL) 768 attrcount_orig++; 769 } 770 attrcount = attrcount_orig; 771 /* 772 * New channel registration method - relies on the fact a group does 773 * not need to be initialized if its name is NULL. 774 */ 775 if (indio_dev->channels) 776 for (i = 0; i < indio_dev->num_channels; i++) { 777 ret = iio_device_add_channel_sysfs(indio_dev, 778 &indio_dev 779 ->channels[i]); 780 if (ret < 0) 781 goto error_clear_attrs; 782 attrcount += ret; 783 } 784 785 if (indio_dev->name) 786 attrcount++; 787 788 indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1, 789 sizeof(indio_dev->chan_attr_group.attrs[0]), 790 GFP_KERNEL); 791 if (indio_dev->chan_attr_group.attrs == NULL) { 792 ret = -ENOMEM; 793 goto error_clear_attrs; 794 } 795 /* Copy across original attributes */ 796 if (indio_dev->info->attrs) 797 memcpy(indio_dev->chan_attr_group.attrs, 798 indio_dev->info->attrs->attrs, 799 sizeof(indio_dev->chan_attr_group.attrs[0]) 800 *attrcount_orig); 801 attrn = attrcount_orig; 802 /* Add all elements from the list. */ 803 list_for_each_entry(p, &indio_dev->channel_attr_list, l) 804 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr; 805 if (indio_dev->name) 806 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr; 807 808 indio_dev->groups[indio_dev->groupcounter++] = 809 &indio_dev->chan_attr_group; 810 811 return 0; 812 813 error_clear_attrs: 814 list_for_each_entry_safe(p, n, 815 &indio_dev->channel_attr_list, l) { 816 list_del(&p->l); 817 iio_device_remove_and_free_read_attr(indio_dev, p); 818 } 819 820 return ret; 821 } 822 823 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) 824 { 825 826 struct iio_dev_attr *p, *n; 827 828 list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) { 829 list_del(&p->l); 830 iio_device_remove_and_free_read_attr(indio_dev, p); 831 } 832 kfree(indio_dev->chan_attr_group.attrs); 833 } 834 835 static void iio_dev_release(struct device *device) 836 { 837 struct iio_dev *indio_dev = dev_to_iio_dev(device); 838 if (indio_dev->chrdev.dev) 839 cdev_del(&indio_dev->chrdev); 840 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) 841 iio_device_unregister_trigger_consumer(indio_dev); 842 iio_device_unregister_eventset(indio_dev); 843 iio_device_unregister_sysfs(indio_dev); 844 iio_device_unregister_debugfs(indio_dev); 845 846 ida_simple_remove(&iio_ida, indio_dev->id); 847 kfree(indio_dev); 848 } 849 850 static struct device_type iio_dev_type = { 851 .name = "iio_device", 852 .release = iio_dev_release, 853 }; 854 855 struct iio_dev *iio_device_alloc(int sizeof_priv) 856 { 857 struct iio_dev *dev; 858 size_t alloc_size; 859 860 alloc_size = sizeof(struct iio_dev); 861 if (sizeof_priv) { 862 alloc_size = ALIGN(alloc_size, IIO_ALIGN); 863 alloc_size += sizeof_priv; 864 } 865 /* ensure 32-byte alignment of whole construct ? */ 866 alloc_size += IIO_ALIGN - 1; 867 868 dev = kzalloc(alloc_size, GFP_KERNEL); 869 870 if (dev) { 871 dev->dev.groups = dev->groups; 872 dev->dev.type = &iio_dev_type; 873 dev->dev.bus = &iio_bus_type; 874 device_initialize(&dev->dev); 875 dev_set_drvdata(&dev->dev, (void *)dev); 876 mutex_init(&dev->mlock); 877 mutex_init(&dev->info_exist_lock); 878 INIT_LIST_HEAD(&dev->channel_attr_list); 879 880 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL); 881 if (dev->id < 0) { 882 /* cannot use a dev_err as the name isn't available */ 883 printk(KERN_ERR "Failed to get id\n"); 884 kfree(dev); 885 return NULL; 886 } 887 dev_set_name(&dev->dev, "iio:device%d", dev->id); 888 INIT_LIST_HEAD(&dev->buffer_list); 889 } 890 891 return dev; 892 } 893 EXPORT_SYMBOL(iio_device_alloc); 894 895 void iio_device_free(struct iio_dev *dev) 896 { 897 if (dev) 898 put_device(&dev->dev); 899 } 900 EXPORT_SYMBOL(iio_device_free); 901 902 /** 903 * iio_chrdev_open() - chrdev file open for buffer access and ioctls 904 **/ 905 static int iio_chrdev_open(struct inode *inode, struct file *filp) 906 { 907 struct iio_dev *indio_dev = container_of(inode->i_cdev, 908 struct iio_dev, chrdev); 909 910 if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags)) 911 return -EBUSY; 912 913 filp->private_data = indio_dev; 914 915 return 0; 916 } 917 918 /** 919 * iio_chrdev_release() - chrdev file close buffer access and ioctls 920 **/ 921 static int iio_chrdev_release(struct inode *inode, struct file *filp) 922 { 923 struct iio_dev *indio_dev = container_of(inode->i_cdev, 924 struct iio_dev, chrdev); 925 clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags); 926 return 0; 927 } 928 929 /* Somewhat of a cross file organization violation - ioctls here are actually 930 * event related */ 931 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 932 { 933 struct iio_dev *indio_dev = filp->private_data; 934 int __user *ip = (int __user *)arg; 935 int fd; 936 937 if (cmd == IIO_GET_EVENT_FD_IOCTL) { 938 fd = iio_event_getfd(indio_dev); 939 if (copy_to_user(ip, &fd, sizeof(fd))) 940 return -EFAULT; 941 return 0; 942 } 943 return -EINVAL; 944 } 945 946 static const struct file_operations iio_buffer_fileops = { 947 .read = iio_buffer_read_first_n_outer_addr, 948 .release = iio_chrdev_release, 949 .open = iio_chrdev_open, 950 .poll = iio_buffer_poll_addr, 951 .owner = THIS_MODULE, 952 .llseek = noop_llseek, 953 .unlocked_ioctl = iio_ioctl, 954 .compat_ioctl = iio_ioctl, 955 }; 956 957 static const struct iio_buffer_setup_ops noop_ring_setup_ops; 958 959 int iio_device_register(struct iio_dev *indio_dev) 960 { 961 int ret; 962 963 /* configure elements for the chrdev */ 964 indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id); 965 966 ret = iio_device_register_debugfs(indio_dev); 967 if (ret) { 968 dev_err(indio_dev->dev.parent, 969 "Failed to register debugfs interfaces\n"); 970 goto error_ret; 971 } 972 ret = iio_device_register_sysfs(indio_dev); 973 if (ret) { 974 dev_err(indio_dev->dev.parent, 975 "Failed to register sysfs interfaces\n"); 976 goto error_unreg_debugfs; 977 } 978 ret = iio_device_register_eventset(indio_dev); 979 if (ret) { 980 dev_err(indio_dev->dev.parent, 981 "Failed to register event set\n"); 982 goto error_free_sysfs; 983 } 984 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) 985 iio_device_register_trigger_consumer(indio_dev); 986 987 if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) && 988 indio_dev->setup_ops == NULL) 989 indio_dev->setup_ops = &noop_ring_setup_ops; 990 991 ret = device_add(&indio_dev->dev); 992 if (ret < 0) 993 goto error_unreg_eventset; 994 cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); 995 indio_dev->chrdev.owner = indio_dev->info->driver_module; 996 ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1); 997 if (ret < 0) 998 goto error_del_device; 999 return 0; 1000 1001 error_del_device: 1002 device_del(&indio_dev->dev); 1003 error_unreg_eventset: 1004 iio_device_unregister_eventset(indio_dev); 1005 error_free_sysfs: 1006 iio_device_unregister_sysfs(indio_dev); 1007 error_unreg_debugfs: 1008 iio_device_unregister_debugfs(indio_dev); 1009 error_ret: 1010 return ret; 1011 } 1012 EXPORT_SYMBOL(iio_device_register); 1013 1014 void iio_device_unregister(struct iio_dev *indio_dev) 1015 { 1016 mutex_lock(&indio_dev->info_exist_lock); 1017 indio_dev->info = NULL; 1018 mutex_unlock(&indio_dev->info_exist_lock); 1019 device_del(&indio_dev->dev); 1020 } 1021 EXPORT_SYMBOL(iio_device_unregister); 1022 subsys_initcall(iio_init); 1023 module_exit(iio_exit); 1024 1025 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); 1026 MODULE_DESCRIPTION("Industrial I/O core"); 1027 MODULE_LICENSE("GPL"); 1028