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 #define pr_fmt(fmt) "iio-core: " fmt 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/idr.h> 17 #include <linux/kdev_t.h> 18 #include <linux/err.h> 19 #include <linux/device.h> 20 #include <linux/fs.h> 21 #include <linux/poll.h> 22 #include <linux/sched.h> 23 #include <linux/wait.h> 24 #include <linux/cdev.h> 25 #include <linux/slab.h> 26 #include <linux/anon_inodes.h> 27 #include <linux/debugfs.h> 28 #include <linux/iio/iio.h> 29 #include "iio_core.h" 30 #include "iio_core_trigger.h" 31 #include <linux/iio/sysfs.h> 32 #include <linux/iio/events.h> 33 #include <linux/iio/buffer.h> 34 35 /* IDA to assign each registered device a unique id */ 36 static DEFINE_IDA(iio_ida); 37 38 static dev_t iio_devt; 39 40 #define IIO_DEV_MAX 256 41 struct bus_type iio_bus_type = { 42 .name = "iio", 43 }; 44 EXPORT_SYMBOL(iio_bus_type); 45 46 static struct dentry *iio_debugfs_dentry; 47 48 static const char * const iio_direction[] = { 49 [0] = "in", 50 [1] = "out", 51 }; 52 53 static const char * const iio_chan_type_name_spec[] = { 54 [IIO_VOLTAGE] = "voltage", 55 [IIO_CURRENT] = "current", 56 [IIO_POWER] = "power", 57 [IIO_ACCEL] = "accel", 58 [IIO_ANGL_VEL] = "anglvel", 59 [IIO_MAGN] = "magn", 60 [IIO_LIGHT] = "illuminance", 61 [IIO_INTENSITY] = "intensity", 62 [IIO_PROXIMITY] = "proximity", 63 [IIO_TEMP] = "temp", 64 [IIO_INCLI] = "incli", 65 [IIO_ROT] = "rot", 66 [IIO_ANGL] = "angl", 67 [IIO_TIMESTAMP] = "timestamp", 68 [IIO_CAPACITANCE] = "capacitance", 69 [IIO_ALTVOLTAGE] = "altvoltage", 70 [IIO_CCT] = "cct", 71 [IIO_PRESSURE] = "pressure", 72 [IIO_HUMIDITYRELATIVE] = "humidityrelative", 73 }; 74 75 static const char * const iio_modifier_names[] = { 76 [IIO_MOD_X] = "x", 77 [IIO_MOD_Y] = "y", 78 [IIO_MOD_Z] = "z", 79 [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)", 80 [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2", 81 [IIO_MOD_LIGHT_BOTH] = "both", 82 [IIO_MOD_LIGHT_IR] = "ir", 83 [IIO_MOD_LIGHT_CLEAR] = "clear", 84 [IIO_MOD_LIGHT_RED] = "red", 85 [IIO_MOD_LIGHT_GREEN] = "green", 86 [IIO_MOD_LIGHT_BLUE] = "blue", 87 }; 88 89 /* relies on pairs of these shared then separate */ 90 static const char * const iio_chan_info_postfix[] = { 91 [IIO_CHAN_INFO_RAW] = "raw", 92 [IIO_CHAN_INFO_PROCESSED] = "input", 93 [IIO_CHAN_INFO_SCALE] = "scale", 94 [IIO_CHAN_INFO_OFFSET] = "offset", 95 [IIO_CHAN_INFO_CALIBSCALE] = "calibscale", 96 [IIO_CHAN_INFO_CALIBBIAS] = "calibbias", 97 [IIO_CHAN_INFO_PEAK] = "peak_raw", 98 [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale", 99 [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw", 100 [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw", 101 [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY] 102 = "filter_low_pass_3db_frequency", 103 [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency", 104 [IIO_CHAN_INFO_FREQUENCY] = "frequency", 105 [IIO_CHAN_INFO_PHASE] = "phase", 106 [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain", 107 [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis", 108 [IIO_CHAN_INFO_INT_TIME] = "integration_time", 109 }; 110 111 /** 112 * iio_find_channel_from_si() - get channel from its scan index 113 * @indio_dev: device 114 * @si: scan index to match 115 */ 116 const struct iio_chan_spec 117 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si) 118 { 119 int i; 120 121 for (i = 0; i < indio_dev->num_channels; i++) 122 if (indio_dev->channels[i].scan_index == si) 123 return &indio_dev->channels[i]; 124 return NULL; 125 } 126 127 /* This turns up an awful lot */ 128 ssize_t iio_read_const_attr(struct device *dev, 129 struct device_attribute *attr, 130 char *buf) 131 { 132 return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string); 133 } 134 EXPORT_SYMBOL(iio_read_const_attr); 135 136 static int __init iio_init(void) 137 { 138 int ret; 139 140 /* Register sysfs bus */ 141 ret = bus_register(&iio_bus_type); 142 if (ret < 0) { 143 pr_err("could not register bus type\n"); 144 goto error_nothing; 145 } 146 147 ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio"); 148 if (ret < 0) { 149 pr_err("failed to allocate char dev region\n"); 150 goto error_unregister_bus_type; 151 } 152 153 iio_debugfs_dentry = debugfs_create_dir("iio", NULL); 154 155 return 0; 156 157 error_unregister_bus_type: 158 bus_unregister(&iio_bus_type); 159 error_nothing: 160 return ret; 161 } 162 163 static void __exit iio_exit(void) 164 { 165 if (iio_devt) 166 unregister_chrdev_region(iio_devt, IIO_DEV_MAX); 167 bus_unregister(&iio_bus_type); 168 debugfs_remove(iio_debugfs_dentry); 169 } 170 171 #if defined(CONFIG_DEBUG_FS) 172 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf, 173 size_t count, loff_t *ppos) 174 { 175 struct iio_dev *indio_dev = file->private_data; 176 char buf[20]; 177 unsigned val = 0; 178 ssize_t len; 179 int ret; 180 181 ret = indio_dev->info->debugfs_reg_access(indio_dev, 182 indio_dev->cached_reg_addr, 183 0, &val); 184 if (ret) 185 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__); 186 187 len = snprintf(buf, sizeof(buf), "0x%X\n", val); 188 189 return simple_read_from_buffer(userbuf, count, ppos, buf, len); 190 } 191 192 static ssize_t iio_debugfs_write_reg(struct file *file, 193 const char __user *userbuf, size_t count, loff_t *ppos) 194 { 195 struct iio_dev *indio_dev = file->private_data; 196 unsigned reg, val; 197 char buf[80]; 198 int ret; 199 200 count = min_t(size_t, count, (sizeof(buf)-1)); 201 if (copy_from_user(buf, userbuf, count)) 202 return -EFAULT; 203 204 buf[count] = 0; 205 206 ret = sscanf(buf, "%i %i", ®, &val); 207 208 switch (ret) { 209 case 1: 210 indio_dev->cached_reg_addr = reg; 211 break; 212 case 2: 213 indio_dev->cached_reg_addr = reg; 214 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg, 215 val, NULL); 216 if (ret) { 217 dev_err(indio_dev->dev.parent, "%s: write failed\n", 218 __func__); 219 return ret; 220 } 221 break; 222 default: 223 return -EINVAL; 224 } 225 226 return count; 227 } 228 229 static const struct file_operations iio_debugfs_reg_fops = { 230 .open = simple_open, 231 .read = iio_debugfs_read_reg, 232 .write = iio_debugfs_write_reg, 233 }; 234 235 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) 236 { 237 debugfs_remove_recursive(indio_dev->debugfs_dentry); 238 } 239 240 static int iio_device_register_debugfs(struct iio_dev *indio_dev) 241 { 242 struct dentry *d; 243 244 if (indio_dev->info->debugfs_reg_access == NULL) 245 return 0; 246 247 if (!iio_debugfs_dentry) 248 return 0; 249 250 indio_dev->debugfs_dentry = 251 debugfs_create_dir(dev_name(&indio_dev->dev), 252 iio_debugfs_dentry); 253 if (indio_dev->debugfs_dentry == NULL) { 254 dev_warn(indio_dev->dev.parent, 255 "Failed to create debugfs directory\n"); 256 return -EFAULT; 257 } 258 259 d = debugfs_create_file("direct_reg_access", 0644, 260 indio_dev->debugfs_dentry, 261 indio_dev, &iio_debugfs_reg_fops); 262 if (!d) { 263 iio_device_unregister_debugfs(indio_dev); 264 return -ENOMEM; 265 } 266 267 return 0; 268 } 269 #else 270 static int iio_device_register_debugfs(struct iio_dev *indio_dev) 271 { 272 return 0; 273 } 274 275 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) 276 { 277 } 278 #endif /* CONFIG_DEBUG_FS */ 279 280 static ssize_t iio_read_channel_ext_info(struct device *dev, 281 struct device_attribute *attr, 282 char *buf) 283 { 284 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 285 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 286 const struct iio_chan_spec_ext_info *ext_info; 287 288 ext_info = &this_attr->c->ext_info[this_attr->address]; 289 290 return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf); 291 } 292 293 static ssize_t iio_write_channel_ext_info(struct device *dev, 294 struct device_attribute *attr, 295 const char *buf, 296 size_t len) 297 { 298 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 299 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 300 const struct iio_chan_spec_ext_info *ext_info; 301 302 ext_info = &this_attr->c->ext_info[this_attr->address]; 303 304 return ext_info->write(indio_dev, ext_info->private, 305 this_attr->c, buf, len); 306 } 307 308 ssize_t iio_enum_available_read(struct iio_dev *indio_dev, 309 uintptr_t priv, const struct iio_chan_spec *chan, char *buf) 310 { 311 const struct iio_enum *e = (const struct iio_enum *)priv; 312 unsigned int i; 313 size_t len = 0; 314 315 if (!e->num_items) 316 return 0; 317 318 for (i = 0; i < e->num_items; ++i) 319 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]); 320 321 /* replace last space with a newline */ 322 buf[len - 1] = '\n'; 323 324 return len; 325 } 326 EXPORT_SYMBOL_GPL(iio_enum_available_read); 327 328 ssize_t iio_enum_read(struct iio_dev *indio_dev, 329 uintptr_t priv, const struct iio_chan_spec *chan, char *buf) 330 { 331 const struct iio_enum *e = (const struct iio_enum *)priv; 332 int i; 333 334 if (!e->get) 335 return -EINVAL; 336 337 i = e->get(indio_dev, chan); 338 if (i < 0) 339 return i; 340 else if (i >= e->num_items) 341 return -EINVAL; 342 343 return sprintf(buf, "%s\n", e->items[i]); 344 } 345 EXPORT_SYMBOL_GPL(iio_enum_read); 346 347 ssize_t iio_enum_write(struct iio_dev *indio_dev, 348 uintptr_t priv, const struct iio_chan_spec *chan, const char *buf, 349 size_t len) 350 { 351 const struct iio_enum *e = (const struct iio_enum *)priv; 352 unsigned int i; 353 int ret; 354 355 if (!e->set) 356 return -EINVAL; 357 358 for (i = 0; i < e->num_items; i++) { 359 if (sysfs_streq(buf, e->items[i])) 360 break; 361 } 362 363 if (i == e->num_items) 364 return -EINVAL; 365 366 ret = e->set(indio_dev, chan, i); 367 return ret ? ret : len; 368 } 369 EXPORT_SYMBOL_GPL(iio_enum_write); 370 371 /** 372 * iio_format_value() - Formats a IIO value into its string representation 373 * @buf: The buffer to which the formated value gets written 374 * @type: One of the IIO_VAL_... constants. This decides how the val and val2 375 * parameters are formatted. 376 * @val: First part of the value, exact meaning depends on the type parameter. 377 * @val2: Second part of the value, exact meaning depends on the type parameter. 378 */ 379 ssize_t iio_format_value(char *buf, unsigned int type, int val, int val2) 380 { 381 unsigned long long tmp; 382 bool scale_db = false; 383 384 switch (type) { 385 case IIO_VAL_INT: 386 return sprintf(buf, "%d\n", val); 387 case IIO_VAL_INT_PLUS_MICRO_DB: 388 scale_db = true; 389 case IIO_VAL_INT_PLUS_MICRO: 390 if (val2 < 0) 391 return sprintf(buf, "-%ld.%06u%s\n", abs(val), -val2, 392 scale_db ? " dB" : ""); 393 else 394 return sprintf(buf, "%d.%06u%s\n", val, val2, 395 scale_db ? " dB" : ""); 396 case IIO_VAL_INT_PLUS_NANO: 397 if (val2 < 0) 398 return sprintf(buf, "-%ld.%09u\n", abs(val), -val2); 399 else 400 return sprintf(buf, "%d.%09u\n", val, val2); 401 case IIO_VAL_FRACTIONAL: 402 tmp = div_s64((s64)val * 1000000000LL, val2); 403 val2 = do_div(tmp, 1000000000LL); 404 val = tmp; 405 return sprintf(buf, "%d.%09u\n", val, val2); 406 case IIO_VAL_FRACTIONAL_LOG2: 407 tmp = (s64)val * 1000000000LL >> val2; 408 val2 = do_div(tmp, 1000000000LL); 409 val = tmp; 410 return sprintf(buf, "%d.%09u\n", val, val2); 411 default: 412 return 0; 413 } 414 } 415 416 static ssize_t iio_read_channel_info(struct device *dev, 417 struct device_attribute *attr, 418 char *buf) 419 { 420 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 421 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 422 int val, val2; 423 int ret = indio_dev->info->read_raw(indio_dev, this_attr->c, 424 &val, &val2, this_attr->address); 425 426 if (ret < 0) 427 return ret; 428 429 return iio_format_value(buf, ret, val, val2); 430 } 431 432 /** 433 * iio_str_to_fixpoint() - Parse a fixed-point number from a string 434 * @str: The string to parse 435 * @fract_mult: Multiplier for the first decimal place, should be a power of 10 436 * @integer: The integer part of the number 437 * @fract: The fractional part of the number 438 * 439 * Returns 0 on success, or a negative error code if the string could not be 440 * parsed. 441 */ 442 int iio_str_to_fixpoint(const char *str, int fract_mult, 443 int *integer, int *fract) 444 { 445 int i = 0, f = 0; 446 bool integer_part = true, negative = false; 447 448 if (str[0] == '-') { 449 negative = true; 450 str++; 451 } else if (str[0] == '+') { 452 str++; 453 } 454 455 while (*str) { 456 if ('0' <= *str && *str <= '9') { 457 if (integer_part) { 458 i = i * 10 + *str - '0'; 459 } else { 460 f += fract_mult * (*str - '0'); 461 fract_mult /= 10; 462 } 463 } else if (*str == '\n') { 464 if (*(str + 1) == '\0') 465 break; 466 else 467 return -EINVAL; 468 } else if (*str == '.' && integer_part) { 469 integer_part = false; 470 } else { 471 return -EINVAL; 472 } 473 str++; 474 } 475 476 if (negative) { 477 if (i) 478 i = -i; 479 else 480 f = -f; 481 } 482 483 *integer = i; 484 *fract = f; 485 486 return 0; 487 } 488 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint); 489 490 static ssize_t iio_write_channel_info(struct device *dev, 491 struct device_attribute *attr, 492 const char *buf, 493 size_t len) 494 { 495 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 496 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 497 int ret, fract_mult = 100000; 498 int integer, fract; 499 500 /* Assumes decimal - precision based on number of digits */ 501 if (!indio_dev->info->write_raw) 502 return -EINVAL; 503 504 if (indio_dev->info->write_raw_get_fmt) 505 switch (indio_dev->info->write_raw_get_fmt(indio_dev, 506 this_attr->c, this_attr->address)) { 507 case IIO_VAL_INT_PLUS_MICRO: 508 fract_mult = 100000; 509 break; 510 case IIO_VAL_INT_PLUS_NANO: 511 fract_mult = 100000000; 512 break; 513 default: 514 return -EINVAL; 515 } 516 517 ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract); 518 if (ret) 519 return ret; 520 521 ret = indio_dev->info->write_raw(indio_dev, this_attr->c, 522 integer, fract, this_attr->address); 523 if (ret) 524 return ret; 525 526 return len; 527 } 528 529 static 530 int __iio_device_attr_init(struct device_attribute *dev_attr, 531 const char *postfix, 532 struct iio_chan_spec const *chan, 533 ssize_t (*readfunc)(struct device *dev, 534 struct device_attribute *attr, 535 char *buf), 536 ssize_t (*writefunc)(struct device *dev, 537 struct device_attribute *attr, 538 const char *buf, 539 size_t len), 540 enum iio_shared_by shared_by) 541 { 542 int ret = 0; 543 char *name = NULL; 544 char *full_postfix; 545 sysfs_attr_init(&dev_attr->attr); 546 547 /* Build up postfix of <extend_name>_<modifier>_postfix */ 548 if (chan->modified && (shared_by == IIO_SEPARATE)) { 549 if (chan->extend_name) 550 full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s", 551 iio_modifier_names[chan 552 ->channel2], 553 chan->extend_name, 554 postfix); 555 else 556 full_postfix = kasprintf(GFP_KERNEL, "%s_%s", 557 iio_modifier_names[chan 558 ->channel2], 559 postfix); 560 } else { 561 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE) 562 full_postfix = kstrdup(postfix, GFP_KERNEL); 563 else 564 full_postfix = kasprintf(GFP_KERNEL, 565 "%s_%s", 566 chan->extend_name, 567 postfix); 568 } 569 if (full_postfix == NULL) 570 return -ENOMEM; 571 572 if (chan->differential) { /* Differential can not have modifier */ 573 switch (shared_by) { 574 case IIO_SHARED_BY_ALL: 575 name = kasprintf(GFP_KERNEL, "%s", full_postfix); 576 break; 577 case IIO_SHARED_BY_DIR: 578 name = kasprintf(GFP_KERNEL, "%s_%s", 579 iio_direction[chan->output], 580 full_postfix); 581 break; 582 case IIO_SHARED_BY_TYPE: 583 name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s", 584 iio_direction[chan->output], 585 iio_chan_type_name_spec[chan->type], 586 iio_chan_type_name_spec[chan->type], 587 full_postfix); 588 break; 589 case IIO_SEPARATE: 590 if (!chan->indexed) { 591 WARN_ON("Differential channels must be indexed\n"); 592 ret = -EINVAL; 593 goto error_free_full_postfix; 594 } 595 name = kasprintf(GFP_KERNEL, 596 "%s_%s%d-%s%d_%s", 597 iio_direction[chan->output], 598 iio_chan_type_name_spec[chan->type], 599 chan->channel, 600 iio_chan_type_name_spec[chan->type], 601 chan->channel2, 602 full_postfix); 603 break; 604 } 605 } else { /* Single ended */ 606 switch (shared_by) { 607 case IIO_SHARED_BY_ALL: 608 name = kasprintf(GFP_KERNEL, "%s", full_postfix); 609 break; 610 case IIO_SHARED_BY_DIR: 611 name = kasprintf(GFP_KERNEL, "%s_%s", 612 iio_direction[chan->output], 613 full_postfix); 614 break; 615 case IIO_SHARED_BY_TYPE: 616 name = kasprintf(GFP_KERNEL, "%s_%s_%s", 617 iio_direction[chan->output], 618 iio_chan_type_name_spec[chan->type], 619 full_postfix); 620 break; 621 622 case IIO_SEPARATE: 623 if (chan->indexed) 624 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s", 625 iio_direction[chan->output], 626 iio_chan_type_name_spec[chan->type], 627 chan->channel, 628 full_postfix); 629 else 630 name = kasprintf(GFP_KERNEL, "%s_%s_%s", 631 iio_direction[chan->output], 632 iio_chan_type_name_spec[chan->type], 633 full_postfix); 634 break; 635 } 636 } 637 if (name == NULL) { 638 ret = -ENOMEM; 639 goto error_free_full_postfix; 640 } 641 dev_attr->attr.name = name; 642 643 if (readfunc) { 644 dev_attr->attr.mode |= S_IRUGO; 645 dev_attr->show = readfunc; 646 } 647 648 if (writefunc) { 649 dev_attr->attr.mode |= S_IWUSR; 650 dev_attr->store = writefunc; 651 } 652 653 error_free_full_postfix: 654 kfree(full_postfix); 655 656 return ret; 657 } 658 659 static void __iio_device_attr_deinit(struct device_attribute *dev_attr) 660 { 661 kfree(dev_attr->attr.name); 662 } 663 664 int __iio_add_chan_devattr(const char *postfix, 665 struct iio_chan_spec const *chan, 666 ssize_t (*readfunc)(struct device *dev, 667 struct device_attribute *attr, 668 char *buf), 669 ssize_t (*writefunc)(struct device *dev, 670 struct device_attribute *attr, 671 const char *buf, 672 size_t len), 673 u64 mask, 674 enum iio_shared_by shared_by, 675 struct device *dev, 676 struct list_head *attr_list) 677 { 678 int ret; 679 struct iio_dev_attr *iio_attr, *t; 680 681 iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL); 682 if (iio_attr == NULL) 683 return -ENOMEM; 684 ret = __iio_device_attr_init(&iio_attr->dev_attr, 685 postfix, chan, 686 readfunc, writefunc, shared_by); 687 if (ret) 688 goto error_iio_dev_attr_free; 689 iio_attr->c = chan; 690 iio_attr->address = mask; 691 list_for_each_entry(t, attr_list, l) 692 if (strcmp(t->dev_attr.attr.name, 693 iio_attr->dev_attr.attr.name) == 0) { 694 if (shared_by == IIO_SEPARATE) 695 dev_err(dev, "tried to double register : %s\n", 696 t->dev_attr.attr.name); 697 ret = -EBUSY; 698 goto error_device_attr_deinit; 699 } 700 list_add(&iio_attr->l, attr_list); 701 702 return 0; 703 704 error_device_attr_deinit: 705 __iio_device_attr_deinit(&iio_attr->dev_attr); 706 error_iio_dev_attr_free: 707 kfree(iio_attr); 708 return ret; 709 } 710 711 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev, 712 struct iio_chan_spec const *chan, 713 enum iio_shared_by shared_by, 714 const long *infomask) 715 { 716 int i, ret, attrcount = 0; 717 718 for_each_set_bit(i, infomask, sizeof(infomask)*8) { 719 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i], 720 chan, 721 &iio_read_channel_info, 722 &iio_write_channel_info, 723 i, 724 shared_by, 725 &indio_dev->dev, 726 &indio_dev->channel_attr_list); 727 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE)) 728 continue; 729 else if (ret < 0) 730 return ret; 731 attrcount++; 732 } 733 734 return attrcount; 735 } 736 737 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev, 738 struct iio_chan_spec const *chan) 739 { 740 int ret, attrcount = 0; 741 const struct iio_chan_spec_ext_info *ext_info; 742 743 if (chan->channel < 0) 744 return 0; 745 ret = iio_device_add_info_mask_type(indio_dev, chan, 746 IIO_SEPARATE, 747 &chan->info_mask_separate); 748 if (ret < 0) 749 return ret; 750 attrcount += ret; 751 752 ret = iio_device_add_info_mask_type(indio_dev, chan, 753 IIO_SHARED_BY_TYPE, 754 &chan->info_mask_shared_by_type); 755 if (ret < 0) 756 return ret; 757 attrcount += ret; 758 759 ret = iio_device_add_info_mask_type(indio_dev, chan, 760 IIO_SHARED_BY_DIR, 761 &chan->info_mask_shared_by_dir); 762 if (ret < 0) 763 return ret; 764 attrcount += ret; 765 766 ret = iio_device_add_info_mask_type(indio_dev, chan, 767 IIO_SHARED_BY_ALL, 768 &chan->info_mask_shared_by_all); 769 if (ret < 0) 770 return ret; 771 attrcount += ret; 772 773 if (chan->ext_info) { 774 unsigned int i = 0; 775 for (ext_info = chan->ext_info; ext_info->name; ext_info++) { 776 ret = __iio_add_chan_devattr(ext_info->name, 777 chan, 778 ext_info->read ? 779 &iio_read_channel_ext_info : NULL, 780 ext_info->write ? 781 &iio_write_channel_ext_info : NULL, 782 i, 783 ext_info->shared, 784 &indio_dev->dev, 785 &indio_dev->channel_attr_list); 786 i++; 787 if (ret == -EBUSY && ext_info->shared) 788 continue; 789 790 if (ret) 791 return ret; 792 793 attrcount++; 794 } 795 } 796 797 return attrcount; 798 } 799 800 /** 801 * iio_free_chan_devattr_list() - Free a list of IIO device attributes 802 * @attr_list: List of IIO device attributes 803 * 804 * This function frees the memory allocated for each of the IIO device 805 * attributes in the list. Note: if you want to reuse the list after calling 806 * this function you have to reinitialize it using INIT_LIST_HEAD(). 807 */ 808 void iio_free_chan_devattr_list(struct list_head *attr_list) 809 { 810 struct iio_dev_attr *p, *n; 811 812 list_for_each_entry_safe(p, n, attr_list, l) { 813 kfree(p->dev_attr.attr.name); 814 kfree(p); 815 } 816 } 817 818 static ssize_t iio_show_dev_name(struct device *dev, 819 struct device_attribute *attr, 820 char *buf) 821 { 822 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 823 return sprintf(buf, "%s\n", indio_dev->name); 824 } 825 826 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL); 827 828 static int iio_device_register_sysfs(struct iio_dev *indio_dev) 829 { 830 int i, ret = 0, attrcount, attrn, attrcount_orig = 0; 831 struct iio_dev_attr *p; 832 struct attribute **attr; 833 834 /* First count elements in any existing group */ 835 if (indio_dev->info->attrs) { 836 attr = indio_dev->info->attrs->attrs; 837 while (*attr++ != NULL) 838 attrcount_orig++; 839 } 840 attrcount = attrcount_orig; 841 /* 842 * New channel registration method - relies on the fact a group does 843 * not need to be initialized if its name is NULL. 844 */ 845 if (indio_dev->channels) 846 for (i = 0; i < indio_dev->num_channels; i++) { 847 ret = iio_device_add_channel_sysfs(indio_dev, 848 &indio_dev 849 ->channels[i]); 850 if (ret < 0) 851 goto error_clear_attrs; 852 attrcount += ret; 853 } 854 855 if (indio_dev->name) 856 attrcount++; 857 858 indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1, 859 sizeof(indio_dev->chan_attr_group.attrs[0]), 860 GFP_KERNEL); 861 if (indio_dev->chan_attr_group.attrs == NULL) { 862 ret = -ENOMEM; 863 goto error_clear_attrs; 864 } 865 /* Copy across original attributes */ 866 if (indio_dev->info->attrs) 867 memcpy(indio_dev->chan_attr_group.attrs, 868 indio_dev->info->attrs->attrs, 869 sizeof(indio_dev->chan_attr_group.attrs[0]) 870 *attrcount_orig); 871 attrn = attrcount_orig; 872 /* Add all elements from the list. */ 873 list_for_each_entry(p, &indio_dev->channel_attr_list, l) 874 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr; 875 if (indio_dev->name) 876 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr; 877 878 indio_dev->groups[indio_dev->groupcounter++] = 879 &indio_dev->chan_attr_group; 880 881 return 0; 882 883 error_clear_attrs: 884 iio_free_chan_devattr_list(&indio_dev->channel_attr_list); 885 886 return ret; 887 } 888 889 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) 890 { 891 892 iio_free_chan_devattr_list(&indio_dev->channel_attr_list); 893 kfree(indio_dev->chan_attr_group.attrs); 894 } 895 896 static void iio_dev_release(struct device *device) 897 { 898 struct iio_dev *indio_dev = dev_to_iio_dev(device); 899 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) 900 iio_device_unregister_trigger_consumer(indio_dev); 901 iio_device_unregister_eventset(indio_dev); 902 iio_device_unregister_sysfs(indio_dev); 903 904 iio_buffer_put(indio_dev->buffer); 905 906 ida_simple_remove(&iio_ida, indio_dev->id); 907 kfree(indio_dev); 908 } 909 910 struct device_type iio_device_type = { 911 .name = "iio_device", 912 .release = iio_dev_release, 913 }; 914 915 /** 916 * iio_device_alloc() - allocate an iio_dev from a driver 917 * @sizeof_priv: Space to allocate for private structure. 918 **/ 919 struct iio_dev *iio_device_alloc(int sizeof_priv) 920 { 921 struct iio_dev *dev; 922 size_t alloc_size; 923 924 alloc_size = sizeof(struct iio_dev); 925 if (sizeof_priv) { 926 alloc_size = ALIGN(alloc_size, IIO_ALIGN); 927 alloc_size += sizeof_priv; 928 } 929 /* ensure 32-byte alignment of whole construct ? */ 930 alloc_size += IIO_ALIGN - 1; 931 932 dev = kzalloc(alloc_size, GFP_KERNEL); 933 934 if (dev) { 935 dev->dev.groups = dev->groups; 936 dev->dev.type = &iio_device_type; 937 dev->dev.bus = &iio_bus_type; 938 device_initialize(&dev->dev); 939 dev_set_drvdata(&dev->dev, (void *)dev); 940 mutex_init(&dev->mlock); 941 mutex_init(&dev->info_exist_lock); 942 INIT_LIST_HEAD(&dev->channel_attr_list); 943 944 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL); 945 if (dev->id < 0) { 946 /* cannot use a dev_err as the name isn't available */ 947 pr_err("failed to get device id\n"); 948 kfree(dev); 949 return NULL; 950 } 951 dev_set_name(&dev->dev, "iio:device%d", dev->id); 952 INIT_LIST_HEAD(&dev->buffer_list); 953 } 954 955 return dev; 956 } 957 EXPORT_SYMBOL(iio_device_alloc); 958 959 /** 960 * iio_device_free() - free an iio_dev from a driver 961 * @dev: the iio_dev associated with the device 962 **/ 963 void iio_device_free(struct iio_dev *dev) 964 { 965 if (dev) 966 put_device(&dev->dev); 967 } 968 EXPORT_SYMBOL(iio_device_free); 969 970 static void devm_iio_device_release(struct device *dev, void *res) 971 { 972 iio_device_free(*(struct iio_dev **)res); 973 } 974 975 static int devm_iio_device_match(struct device *dev, void *res, void *data) 976 { 977 struct iio_dev **r = res; 978 if (!r || !*r) { 979 WARN_ON(!r || !*r); 980 return 0; 981 } 982 return *r == data; 983 } 984 985 /** 986 * devm_iio_device_alloc - Resource-managed iio_device_alloc() 987 * @dev: Device to allocate iio_dev for 988 * @sizeof_priv: Space to allocate for private structure. 989 * 990 * Managed iio_device_alloc. iio_dev allocated with this function is 991 * automatically freed on driver detach. 992 * 993 * If an iio_dev allocated with this function needs to be freed separately, 994 * devm_iio_device_free() must be used. 995 * 996 * RETURNS: 997 * Pointer to allocated iio_dev on success, NULL on failure. 998 */ 999 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv) 1000 { 1001 struct iio_dev **ptr, *iio_dev; 1002 1003 ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr), 1004 GFP_KERNEL); 1005 if (!ptr) 1006 return NULL; 1007 1008 /* use raw alloc_dr for kmalloc caller tracing */ 1009 iio_dev = iio_device_alloc(sizeof_priv); 1010 if (iio_dev) { 1011 *ptr = iio_dev; 1012 devres_add(dev, ptr); 1013 } else { 1014 devres_free(ptr); 1015 } 1016 1017 return iio_dev; 1018 } 1019 EXPORT_SYMBOL_GPL(devm_iio_device_alloc); 1020 1021 /** 1022 * devm_iio_device_free - Resource-managed iio_device_free() 1023 * @dev: Device this iio_dev belongs to 1024 * @iio_dev: the iio_dev associated with the device 1025 * 1026 * Free iio_dev allocated with devm_iio_device_alloc(). 1027 */ 1028 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev) 1029 { 1030 int rc; 1031 1032 rc = devres_release(dev, devm_iio_device_release, 1033 devm_iio_device_match, iio_dev); 1034 WARN_ON(rc); 1035 } 1036 EXPORT_SYMBOL_GPL(devm_iio_device_free); 1037 1038 /** 1039 * iio_chrdev_open() - chrdev file open for buffer access and ioctls 1040 **/ 1041 static int iio_chrdev_open(struct inode *inode, struct file *filp) 1042 { 1043 struct iio_dev *indio_dev = container_of(inode->i_cdev, 1044 struct iio_dev, chrdev); 1045 1046 if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags)) 1047 return -EBUSY; 1048 1049 iio_device_get(indio_dev); 1050 1051 filp->private_data = indio_dev; 1052 1053 return 0; 1054 } 1055 1056 /** 1057 * iio_chrdev_release() - chrdev file close buffer access and ioctls 1058 **/ 1059 static int iio_chrdev_release(struct inode *inode, struct file *filp) 1060 { 1061 struct iio_dev *indio_dev = container_of(inode->i_cdev, 1062 struct iio_dev, chrdev); 1063 clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags); 1064 iio_device_put(indio_dev); 1065 1066 return 0; 1067 } 1068 1069 /* Somewhat of a cross file organization violation - ioctls here are actually 1070 * event related */ 1071 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 1072 { 1073 struct iio_dev *indio_dev = filp->private_data; 1074 int __user *ip = (int __user *)arg; 1075 int fd; 1076 1077 if (!indio_dev->info) 1078 return -ENODEV; 1079 1080 if (cmd == IIO_GET_EVENT_FD_IOCTL) { 1081 fd = iio_event_getfd(indio_dev); 1082 if (copy_to_user(ip, &fd, sizeof(fd))) 1083 return -EFAULT; 1084 return 0; 1085 } 1086 return -EINVAL; 1087 } 1088 1089 static const struct file_operations iio_buffer_fileops = { 1090 .read = iio_buffer_read_first_n_outer_addr, 1091 .release = iio_chrdev_release, 1092 .open = iio_chrdev_open, 1093 .poll = iio_buffer_poll_addr, 1094 .owner = THIS_MODULE, 1095 .llseek = noop_llseek, 1096 .unlocked_ioctl = iio_ioctl, 1097 .compat_ioctl = iio_ioctl, 1098 }; 1099 1100 static const struct iio_buffer_setup_ops noop_ring_setup_ops; 1101 1102 /** 1103 * iio_device_register() - register a device with the IIO subsystem 1104 * @indio_dev: Device structure filled by the device driver 1105 **/ 1106 int iio_device_register(struct iio_dev *indio_dev) 1107 { 1108 int ret; 1109 1110 /* If the calling driver did not initialize of_node, do it here */ 1111 if (!indio_dev->dev.of_node && indio_dev->dev.parent) 1112 indio_dev->dev.of_node = indio_dev->dev.parent->of_node; 1113 1114 /* configure elements for the chrdev */ 1115 indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id); 1116 1117 ret = iio_device_register_debugfs(indio_dev); 1118 if (ret) { 1119 dev_err(indio_dev->dev.parent, 1120 "Failed to register debugfs interfaces\n"); 1121 return ret; 1122 } 1123 ret = iio_device_register_sysfs(indio_dev); 1124 if (ret) { 1125 dev_err(indio_dev->dev.parent, 1126 "Failed to register sysfs interfaces\n"); 1127 goto error_unreg_debugfs; 1128 } 1129 ret = iio_device_register_eventset(indio_dev); 1130 if (ret) { 1131 dev_err(indio_dev->dev.parent, 1132 "Failed to register event set\n"); 1133 goto error_free_sysfs; 1134 } 1135 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) 1136 iio_device_register_trigger_consumer(indio_dev); 1137 1138 if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) && 1139 indio_dev->setup_ops == NULL) 1140 indio_dev->setup_ops = &noop_ring_setup_ops; 1141 1142 cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); 1143 indio_dev->chrdev.owner = indio_dev->info->driver_module; 1144 indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj; 1145 ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1); 1146 if (ret < 0) 1147 goto error_unreg_eventset; 1148 1149 ret = device_add(&indio_dev->dev); 1150 if (ret < 0) 1151 goto error_cdev_del; 1152 1153 return 0; 1154 error_cdev_del: 1155 cdev_del(&indio_dev->chrdev); 1156 error_unreg_eventset: 1157 iio_device_unregister_eventset(indio_dev); 1158 error_free_sysfs: 1159 iio_device_unregister_sysfs(indio_dev); 1160 error_unreg_debugfs: 1161 iio_device_unregister_debugfs(indio_dev); 1162 return ret; 1163 } 1164 EXPORT_SYMBOL(iio_device_register); 1165 1166 /** 1167 * iio_device_unregister() - unregister a device from the IIO subsystem 1168 * @indio_dev: Device structure representing the device. 1169 **/ 1170 void iio_device_unregister(struct iio_dev *indio_dev) 1171 { 1172 mutex_lock(&indio_dev->info_exist_lock); 1173 1174 device_del(&indio_dev->dev); 1175 1176 if (indio_dev->chrdev.dev) 1177 cdev_del(&indio_dev->chrdev); 1178 iio_device_unregister_debugfs(indio_dev); 1179 1180 iio_disable_all_buffers(indio_dev); 1181 1182 indio_dev->info = NULL; 1183 1184 iio_device_wakeup_eventset(indio_dev); 1185 iio_buffer_wakeup_poll(indio_dev); 1186 1187 mutex_unlock(&indio_dev->info_exist_lock); 1188 } 1189 EXPORT_SYMBOL(iio_device_unregister); 1190 1191 static void devm_iio_device_unreg(struct device *dev, void *res) 1192 { 1193 iio_device_unregister(*(struct iio_dev **)res); 1194 } 1195 1196 /** 1197 * devm_iio_device_register - Resource-managed iio_device_register() 1198 * @dev: Device to allocate iio_dev for 1199 * @indio_dev: Device structure filled by the device driver 1200 * 1201 * Managed iio_device_register. The IIO device registered with this 1202 * function is automatically unregistered on driver detach. This function 1203 * calls iio_device_register() internally. Refer to that function for more 1204 * information. 1205 * 1206 * If an iio_dev registered with this function needs to be unregistered 1207 * separately, devm_iio_device_unregister() must be used. 1208 * 1209 * RETURNS: 1210 * 0 on success, negative error number on failure. 1211 */ 1212 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev) 1213 { 1214 struct iio_dev **ptr; 1215 int ret; 1216 1217 ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL); 1218 if (!ptr) 1219 return -ENOMEM; 1220 1221 *ptr = indio_dev; 1222 ret = iio_device_register(indio_dev); 1223 if (!ret) 1224 devres_add(dev, ptr); 1225 else 1226 devres_free(ptr); 1227 1228 return ret; 1229 } 1230 EXPORT_SYMBOL_GPL(devm_iio_device_register); 1231 1232 /** 1233 * devm_iio_device_unregister - Resource-managed iio_device_unregister() 1234 * @dev: Device this iio_dev belongs to 1235 * @indio_dev: the iio_dev associated with the device 1236 * 1237 * Unregister iio_dev registered with devm_iio_device_register(). 1238 */ 1239 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev) 1240 { 1241 int rc; 1242 1243 rc = devres_release(dev, devm_iio_device_unreg, 1244 devm_iio_device_match, indio_dev); 1245 WARN_ON(rc); 1246 } 1247 EXPORT_SYMBOL_GPL(devm_iio_device_unregister); 1248 1249 subsys_initcall(iio_init); 1250 module_exit(iio_exit); 1251 1252 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); 1253 MODULE_DESCRIPTION("Industrial I/O core"); 1254 MODULE_LICENSE("GPL"); 1255