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 [IIO_ACTIVITY] = "activity", 74 [IIO_STEPS] = "steps", 75 [IIO_ENERGY] = "energy", 76 [IIO_DISTANCE] = "distance", 77 [IIO_VELOCITY] = "velocity", 78 }; 79 80 static const char * const iio_modifier_names[] = { 81 [IIO_MOD_X] = "x", 82 [IIO_MOD_Y] = "y", 83 [IIO_MOD_Z] = "z", 84 [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)", 85 [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2", 86 [IIO_MOD_LIGHT_BOTH] = "both", 87 [IIO_MOD_LIGHT_IR] = "ir", 88 [IIO_MOD_LIGHT_CLEAR] = "clear", 89 [IIO_MOD_LIGHT_RED] = "red", 90 [IIO_MOD_LIGHT_GREEN] = "green", 91 [IIO_MOD_LIGHT_BLUE] = "blue", 92 [IIO_MOD_QUATERNION] = "quaternion", 93 [IIO_MOD_TEMP_AMBIENT] = "ambient", 94 [IIO_MOD_TEMP_OBJECT] = "object", 95 [IIO_MOD_NORTH_MAGN] = "from_north_magnetic", 96 [IIO_MOD_NORTH_TRUE] = "from_north_true", 97 [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp", 98 [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp", 99 [IIO_MOD_RUNNING] = "running", 100 [IIO_MOD_JOGGING] = "jogging", 101 [IIO_MOD_WALKING] = "walking", 102 [IIO_MOD_STILL] = "still", 103 [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)", 104 [IIO_MOD_I] = "i", 105 [IIO_MOD_Q] = "q", 106 }; 107 108 /* relies on pairs of these shared then separate */ 109 static const char * const iio_chan_info_postfix[] = { 110 [IIO_CHAN_INFO_RAW] = "raw", 111 [IIO_CHAN_INFO_PROCESSED] = "input", 112 [IIO_CHAN_INFO_SCALE] = "scale", 113 [IIO_CHAN_INFO_OFFSET] = "offset", 114 [IIO_CHAN_INFO_CALIBSCALE] = "calibscale", 115 [IIO_CHAN_INFO_CALIBBIAS] = "calibbias", 116 [IIO_CHAN_INFO_PEAK] = "peak_raw", 117 [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale", 118 [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw", 119 [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw", 120 [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY] 121 = "filter_low_pass_3db_frequency", 122 [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY] 123 = "filter_high_pass_3db_frequency", 124 [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency", 125 [IIO_CHAN_INFO_FREQUENCY] = "frequency", 126 [IIO_CHAN_INFO_PHASE] = "phase", 127 [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain", 128 [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis", 129 [IIO_CHAN_INFO_INT_TIME] = "integration_time", 130 [IIO_CHAN_INFO_ENABLE] = "en", 131 [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight", 132 [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight", 133 [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count", 134 [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time", 135 [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity", 136 [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio", 137 }; 138 139 /** 140 * iio_find_channel_from_si() - get channel from its scan index 141 * @indio_dev: device 142 * @si: scan index to match 143 */ 144 const struct iio_chan_spec 145 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si) 146 { 147 int i; 148 149 for (i = 0; i < indio_dev->num_channels; i++) 150 if (indio_dev->channels[i].scan_index == si) 151 return &indio_dev->channels[i]; 152 return NULL; 153 } 154 155 /* This turns up an awful lot */ 156 ssize_t iio_read_const_attr(struct device *dev, 157 struct device_attribute *attr, 158 char *buf) 159 { 160 return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string); 161 } 162 EXPORT_SYMBOL(iio_read_const_attr); 163 164 static int __init iio_init(void) 165 { 166 int ret; 167 168 /* Register sysfs bus */ 169 ret = bus_register(&iio_bus_type); 170 if (ret < 0) { 171 pr_err("could not register bus type\n"); 172 goto error_nothing; 173 } 174 175 ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio"); 176 if (ret < 0) { 177 pr_err("failed to allocate char dev region\n"); 178 goto error_unregister_bus_type; 179 } 180 181 iio_debugfs_dentry = debugfs_create_dir("iio", NULL); 182 183 return 0; 184 185 error_unregister_bus_type: 186 bus_unregister(&iio_bus_type); 187 error_nothing: 188 return ret; 189 } 190 191 static void __exit iio_exit(void) 192 { 193 if (iio_devt) 194 unregister_chrdev_region(iio_devt, IIO_DEV_MAX); 195 bus_unregister(&iio_bus_type); 196 debugfs_remove(iio_debugfs_dentry); 197 } 198 199 #if defined(CONFIG_DEBUG_FS) 200 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf, 201 size_t count, loff_t *ppos) 202 { 203 struct iio_dev *indio_dev = file->private_data; 204 char buf[20]; 205 unsigned val = 0; 206 ssize_t len; 207 int ret; 208 209 ret = indio_dev->info->debugfs_reg_access(indio_dev, 210 indio_dev->cached_reg_addr, 211 0, &val); 212 if (ret) 213 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__); 214 215 len = snprintf(buf, sizeof(buf), "0x%X\n", val); 216 217 return simple_read_from_buffer(userbuf, count, ppos, buf, len); 218 } 219 220 static ssize_t iio_debugfs_write_reg(struct file *file, 221 const char __user *userbuf, size_t count, loff_t *ppos) 222 { 223 struct iio_dev *indio_dev = file->private_data; 224 unsigned reg, val; 225 char buf[80]; 226 int ret; 227 228 count = min_t(size_t, count, (sizeof(buf)-1)); 229 if (copy_from_user(buf, userbuf, count)) 230 return -EFAULT; 231 232 buf[count] = 0; 233 234 ret = sscanf(buf, "%i %i", ®, &val); 235 236 switch (ret) { 237 case 1: 238 indio_dev->cached_reg_addr = reg; 239 break; 240 case 2: 241 indio_dev->cached_reg_addr = reg; 242 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg, 243 val, NULL); 244 if (ret) { 245 dev_err(indio_dev->dev.parent, "%s: write failed\n", 246 __func__); 247 return ret; 248 } 249 break; 250 default: 251 return -EINVAL; 252 } 253 254 return count; 255 } 256 257 static const struct file_operations iio_debugfs_reg_fops = { 258 .open = simple_open, 259 .read = iio_debugfs_read_reg, 260 .write = iio_debugfs_write_reg, 261 }; 262 263 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) 264 { 265 debugfs_remove_recursive(indio_dev->debugfs_dentry); 266 } 267 268 static int iio_device_register_debugfs(struct iio_dev *indio_dev) 269 { 270 struct dentry *d; 271 272 if (indio_dev->info->debugfs_reg_access == NULL) 273 return 0; 274 275 if (!iio_debugfs_dentry) 276 return 0; 277 278 indio_dev->debugfs_dentry = 279 debugfs_create_dir(dev_name(&indio_dev->dev), 280 iio_debugfs_dentry); 281 if (indio_dev->debugfs_dentry == NULL) { 282 dev_warn(indio_dev->dev.parent, 283 "Failed to create debugfs directory\n"); 284 return -EFAULT; 285 } 286 287 d = debugfs_create_file("direct_reg_access", 0644, 288 indio_dev->debugfs_dentry, 289 indio_dev, &iio_debugfs_reg_fops); 290 if (!d) { 291 iio_device_unregister_debugfs(indio_dev); 292 return -ENOMEM; 293 } 294 295 return 0; 296 } 297 #else 298 static int iio_device_register_debugfs(struct iio_dev *indio_dev) 299 { 300 return 0; 301 } 302 303 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev) 304 { 305 } 306 #endif /* CONFIG_DEBUG_FS */ 307 308 static ssize_t iio_read_channel_ext_info(struct device *dev, 309 struct device_attribute *attr, 310 char *buf) 311 { 312 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 313 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 314 const struct iio_chan_spec_ext_info *ext_info; 315 316 ext_info = &this_attr->c->ext_info[this_attr->address]; 317 318 return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf); 319 } 320 321 static ssize_t iio_write_channel_ext_info(struct device *dev, 322 struct device_attribute *attr, 323 const char *buf, 324 size_t len) 325 { 326 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 327 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 328 const struct iio_chan_spec_ext_info *ext_info; 329 330 ext_info = &this_attr->c->ext_info[this_attr->address]; 331 332 return ext_info->write(indio_dev, ext_info->private, 333 this_attr->c, buf, len); 334 } 335 336 ssize_t iio_enum_available_read(struct iio_dev *indio_dev, 337 uintptr_t priv, const struct iio_chan_spec *chan, char *buf) 338 { 339 const struct iio_enum *e = (const struct iio_enum *)priv; 340 unsigned int i; 341 size_t len = 0; 342 343 if (!e->num_items) 344 return 0; 345 346 for (i = 0; i < e->num_items; ++i) 347 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]); 348 349 /* replace last space with a newline */ 350 buf[len - 1] = '\n'; 351 352 return len; 353 } 354 EXPORT_SYMBOL_GPL(iio_enum_available_read); 355 356 ssize_t iio_enum_read(struct iio_dev *indio_dev, 357 uintptr_t priv, const struct iio_chan_spec *chan, char *buf) 358 { 359 const struct iio_enum *e = (const struct iio_enum *)priv; 360 int i; 361 362 if (!e->get) 363 return -EINVAL; 364 365 i = e->get(indio_dev, chan); 366 if (i < 0) 367 return i; 368 else if (i >= e->num_items) 369 return -EINVAL; 370 371 return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]); 372 } 373 EXPORT_SYMBOL_GPL(iio_enum_read); 374 375 ssize_t iio_enum_write(struct iio_dev *indio_dev, 376 uintptr_t priv, const struct iio_chan_spec *chan, const char *buf, 377 size_t len) 378 { 379 const struct iio_enum *e = (const struct iio_enum *)priv; 380 unsigned int i; 381 int ret; 382 383 if (!e->set) 384 return -EINVAL; 385 386 for (i = 0; i < e->num_items; i++) { 387 if (sysfs_streq(buf, e->items[i])) 388 break; 389 } 390 391 if (i == e->num_items) 392 return -EINVAL; 393 394 ret = e->set(indio_dev, chan, i); 395 return ret ? ret : len; 396 } 397 EXPORT_SYMBOL_GPL(iio_enum_write); 398 399 /** 400 * iio_format_value() - Formats a IIO value into its string representation 401 * @buf: The buffer to which the formated value gets written 402 * @type: One of the IIO_VAL_... constants. This decides how the val and val2 403 * parameters are formatted. 404 * @vals: pointer to the values, exact meaning depends on the type parameter. 405 */ 406 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals) 407 { 408 unsigned long long tmp; 409 bool scale_db = false; 410 411 switch (type) { 412 case IIO_VAL_INT: 413 return sprintf(buf, "%d\n", vals[0]); 414 case IIO_VAL_INT_PLUS_MICRO_DB: 415 scale_db = true; 416 case IIO_VAL_INT_PLUS_MICRO: 417 if (vals[1] < 0) 418 return sprintf(buf, "-%ld.%06u%s\n", abs(vals[0]), 419 -vals[1], 420 scale_db ? " dB" : ""); 421 else 422 return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1], 423 scale_db ? " dB" : ""); 424 case IIO_VAL_INT_PLUS_NANO: 425 if (vals[1] < 0) 426 return sprintf(buf, "-%ld.%09u\n", abs(vals[0]), 427 -vals[1]); 428 else 429 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); 430 case IIO_VAL_FRACTIONAL: 431 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]); 432 vals[1] = do_div(tmp, 1000000000LL); 433 vals[0] = tmp; 434 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); 435 case IIO_VAL_FRACTIONAL_LOG2: 436 tmp = (s64)vals[0] * 1000000000LL >> vals[1]; 437 vals[1] = do_div(tmp, 1000000000LL); 438 vals[0] = tmp; 439 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); 440 case IIO_VAL_INT_MULTIPLE: 441 { 442 int i; 443 int len = 0; 444 445 for (i = 0; i < size; ++i) 446 len += snprintf(&buf[len], PAGE_SIZE - len, "%d ", 447 vals[i]); 448 len += snprintf(&buf[len], PAGE_SIZE - len, "\n"); 449 return len; 450 } 451 default: 452 return 0; 453 } 454 } 455 456 static ssize_t iio_read_channel_info(struct device *dev, 457 struct device_attribute *attr, 458 char *buf) 459 { 460 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 461 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 462 int vals[INDIO_MAX_RAW_ELEMENTS]; 463 int ret; 464 int val_len = 2; 465 466 if (indio_dev->info->read_raw_multi) 467 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c, 468 INDIO_MAX_RAW_ELEMENTS, 469 vals, &val_len, 470 this_attr->address); 471 else 472 ret = indio_dev->info->read_raw(indio_dev, this_attr->c, 473 &vals[0], &vals[1], this_attr->address); 474 475 if (ret < 0) 476 return ret; 477 478 return iio_format_value(buf, ret, val_len, vals); 479 } 480 481 /** 482 * iio_str_to_fixpoint() - Parse a fixed-point number from a string 483 * @str: The string to parse 484 * @fract_mult: Multiplier for the first decimal place, should be a power of 10 485 * @integer: The integer part of the number 486 * @fract: The fractional part of the number 487 * 488 * Returns 0 on success, or a negative error code if the string could not be 489 * parsed. 490 */ 491 int iio_str_to_fixpoint(const char *str, int fract_mult, 492 int *integer, int *fract) 493 { 494 int i = 0, f = 0; 495 bool integer_part = true, negative = false; 496 497 if (str[0] == '-') { 498 negative = true; 499 str++; 500 } else if (str[0] == '+') { 501 str++; 502 } 503 504 while (*str) { 505 if ('0' <= *str && *str <= '9') { 506 if (integer_part) { 507 i = i * 10 + *str - '0'; 508 } else { 509 f += fract_mult * (*str - '0'); 510 fract_mult /= 10; 511 } 512 } else if (*str == '\n') { 513 if (*(str + 1) == '\0') 514 break; 515 else 516 return -EINVAL; 517 } else if (*str == '.' && integer_part) { 518 integer_part = false; 519 } else { 520 return -EINVAL; 521 } 522 str++; 523 } 524 525 if (negative) { 526 if (i) 527 i = -i; 528 else 529 f = -f; 530 } 531 532 *integer = i; 533 *fract = f; 534 535 return 0; 536 } 537 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint); 538 539 static ssize_t iio_write_channel_info(struct device *dev, 540 struct device_attribute *attr, 541 const char *buf, 542 size_t len) 543 { 544 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 545 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); 546 int ret, fract_mult = 100000; 547 int integer, fract; 548 549 /* Assumes decimal - precision based on number of digits */ 550 if (!indio_dev->info->write_raw) 551 return -EINVAL; 552 553 if (indio_dev->info->write_raw_get_fmt) 554 switch (indio_dev->info->write_raw_get_fmt(indio_dev, 555 this_attr->c, this_attr->address)) { 556 case IIO_VAL_INT_PLUS_MICRO: 557 fract_mult = 100000; 558 break; 559 case IIO_VAL_INT_PLUS_NANO: 560 fract_mult = 100000000; 561 break; 562 default: 563 return -EINVAL; 564 } 565 566 ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract); 567 if (ret) 568 return ret; 569 570 ret = indio_dev->info->write_raw(indio_dev, this_attr->c, 571 integer, fract, this_attr->address); 572 if (ret) 573 return ret; 574 575 return len; 576 } 577 578 static 579 int __iio_device_attr_init(struct device_attribute *dev_attr, 580 const char *postfix, 581 struct iio_chan_spec const *chan, 582 ssize_t (*readfunc)(struct device *dev, 583 struct device_attribute *attr, 584 char *buf), 585 ssize_t (*writefunc)(struct device *dev, 586 struct device_attribute *attr, 587 const char *buf, 588 size_t len), 589 enum iio_shared_by shared_by) 590 { 591 int ret = 0; 592 char *name = NULL; 593 char *full_postfix; 594 sysfs_attr_init(&dev_attr->attr); 595 596 /* Build up postfix of <extend_name>_<modifier>_postfix */ 597 if (chan->modified && (shared_by == IIO_SEPARATE)) { 598 if (chan->extend_name) 599 full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s", 600 iio_modifier_names[chan 601 ->channel2], 602 chan->extend_name, 603 postfix); 604 else 605 full_postfix = kasprintf(GFP_KERNEL, "%s_%s", 606 iio_modifier_names[chan 607 ->channel2], 608 postfix); 609 } else { 610 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE) 611 full_postfix = kstrdup(postfix, GFP_KERNEL); 612 else 613 full_postfix = kasprintf(GFP_KERNEL, 614 "%s_%s", 615 chan->extend_name, 616 postfix); 617 } 618 if (full_postfix == NULL) 619 return -ENOMEM; 620 621 if (chan->differential) { /* Differential can not have modifier */ 622 switch (shared_by) { 623 case IIO_SHARED_BY_ALL: 624 name = kasprintf(GFP_KERNEL, "%s", full_postfix); 625 break; 626 case IIO_SHARED_BY_DIR: 627 name = kasprintf(GFP_KERNEL, "%s_%s", 628 iio_direction[chan->output], 629 full_postfix); 630 break; 631 case IIO_SHARED_BY_TYPE: 632 name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s", 633 iio_direction[chan->output], 634 iio_chan_type_name_spec[chan->type], 635 iio_chan_type_name_spec[chan->type], 636 full_postfix); 637 break; 638 case IIO_SEPARATE: 639 if (!chan->indexed) { 640 WARN_ON("Differential channels must be indexed\n"); 641 ret = -EINVAL; 642 goto error_free_full_postfix; 643 } 644 name = kasprintf(GFP_KERNEL, 645 "%s_%s%d-%s%d_%s", 646 iio_direction[chan->output], 647 iio_chan_type_name_spec[chan->type], 648 chan->channel, 649 iio_chan_type_name_spec[chan->type], 650 chan->channel2, 651 full_postfix); 652 break; 653 } 654 } else { /* Single ended */ 655 switch (shared_by) { 656 case IIO_SHARED_BY_ALL: 657 name = kasprintf(GFP_KERNEL, "%s", full_postfix); 658 break; 659 case IIO_SHARED_BY_DIR: 660 name = kasprintf(GFP_KERNEL, "%s_%s", 661 iio_direction[chan->output], 662 full_postfix); 663 break; 664 case IIO_SHARED_BY_TYPE: 665 name = kasprintf(GFP_KERNEL, "%s_%s_%s", 666 iio_direction[chan->output], 667 iio_chan_type_name_spec[chan->type], 668 full_postfix); 669 break; 670 671 case IIO_SEPARATE: 672 if (chan->indexed) 673 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s", 674 iio_direction[chan->output], 675 iio_chan_type_name_spec[chan->type], 676 chan->channel, 677 full_postfix); 678 else 679 name = kasprintf(GFP_KERNEL, "%s_%s_%s", 680 iio_direction[chan->output], 681 iio_chan_type_name_spec[chan->type], 682 full_postfix); 683 break; 684 } 685 } 686 if (name == NULL) { 687 ret = -ENOMEM; 688 goto error_free_full_postfix; 689 } 690 dev_attr->attr.name = name; 691 692 if (readfunc) { 693 dev_attr->attr.mode |= S_IRUGO; 694 dev_attr->show = readfunc; 695 } 696 697 if (writefunc) { 698 dev_attr->attr.mode |= S_IWUSR; 699 dev_attr->store = writefunc; 700 } 701 702 error_free_full_postfix: 703 kfree(full_postfix); 704 705 return ret; 706 } 707 708 static void __iio_device_attr_deinit(struct device_attribute *dev_attr) 709 { 710 kfree(dev_attr->attr.name); 711 } 712 713 int __iio_add_chan_devattr(const char *postfix, 714 struct iio_chan_spec const *chan, 715 ssize_t (*readfunc)(struct device *dev, 716 struct device_attribute *attr, 717 char *buf), 718 ssize_t (*writefunc)(struct device *dev, 719 struct device_attribute *attr, 720 const char *buf, 721 size_t len), 722 u64 mask, 723 enum iio_shared_by shared_by, 724 struct device *dev, 725 struct list_head *attr_list) 726 { 727 int ret; 728 struct iio_dev_attr *iio_attr, *t; 729 730 iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL); 731 if (iio_attr == NULL) 732 return -ENOMEM; 733 ret = __iio_device_attr_init(&iio_attr->dev_attr, 734 postfix, chan, 735 readfunc, writefunc, shared_by); 736 if (ret) 737 goto error_iio_dev_attr_free; 738 iio_attr->c = chan; 739 iio_attr->address = mask; 740 list_for_each_entry(t, attr_list, l) 741 if (strcmp(t->dev_attr.attr.name, 742 iio_attr->dev_attr.attr.name) == 0) { 743 if (shared_by == IIO_SEPARATE) 744 dev_err(dev, "tried to double register : %s\n", 745 t->dev_attr.attr.name); 746 ret = -EBUSY; 747 goto error_device_attr_deinit; 748 } 749 list_add(&iio_attr->l, attr_list); 750 751 return 0; 752 753 error_device_attr_deinit: 754 __iio_device_attr_deinit(&iio_attr->dev_attr); 755 error_iio_dev_attr_free: 756 kfree(iio_attr); 757 return ret; 758 } 759 760 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev, 761 struct iio_chan_spec const *chan, 762 enum iio_shared_by shared_by, 763 const long *infomask) 764 { 765 int i, ret, attrcount = 0; 766 767 for_each_set_bit(i, infomask, sizeof(infomask)*8) { 768 if (i >= ARRAY_SIZE(iio_chan_info_postfix)) 769 return -EINVAL; 770 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i], 771 chan, 772 &iio_read_channel_info, 773 &iio_write_channel_info, 774 i, 775 shared_by, 776 &indio_dev->dev, 777 &indio_dev->channel_attr_list); 778 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE)) 779 continue; 780 else if (ret < 0) 781 return ret; 782 attrcount++; 783 } 784 785 return attrcount; 786 } 787 788 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev, 789 struct iio_chan_spec const *chan) 790 { 791 int ret, attrcount = 0; 792 const struct iio_chan_spec_ext_info *ext_info; 793 794 if (chan->channel < 0) 795 return 0; 796 ret = iio_device_add_info_mask_type(indio_dev, chan, 797 IIO_SEPARATE, 798 &chan->info_mask_separate); 799 if (ret < 0) 800 return ret; 801 attrcount += ret; 802 803 ret = iio_device_add_info_mask_type(indio_dev, chan, 804 IIO_SHARED_BY_TYPE, 805 &chan->info_mask_shared_by_type); 806 if (ret < 0) 807 return ret; 808 attrcount += ret; 809 810 ret = iio_device_add_info_mask_type(indio_dev, chan, 811 IIO_SHARED_BY_DIR, 812 &chan->info_mask_shared_by_dir); 813 if (ret < 0) 814 return ret; 815 attrcount += ret; 816 817 ret = iio_device_add_info_mask_type(indio_dev, chan, 818 IIO_SHARED_BY_ALL, 819 &chan->info_mask_shared_by_all); 820 if (ret < 0) 821 return ret; 822 attrcount += ret; 823 824 if (chan->ext_info) { 825 unsigned int i = 0; 826 for (ext_info = chan->ext_info; ext_info->name; ext_info++) { 827 ret = __iio_add_chan_devattr(ext_info->name, 828 chan, 829 ext_info->read ? 830 &iio_read_channel_ext_info : NULL, 831 ext_info->write ? 832 &iio_write_channel_ext_info : NULL, 833 i, 834 ext_info->shared, 835 &indio_dev->dev, 836 &indio_dev->channel_attr_list); 837 i++; 838 if (ret == -EBUSY && ext_info->shared) 839 continue; 840 841 if (ret) 842 return ret; 843 844 attrcount++; 845 } 846 } 847 848 return attrcount; 849 } 850 851 /** 852 * iio_free_chan_devattr_list() - Free a list of IIO device attributes 853 * @attr_list: List of IIO device attributes 854 * 855 * This function frees the memory allocated for each of the IIO device 856 * attributes in the list. 857 */ 858 void iio_free_chan_devattr_list(struct list_head *attr_list) 859 { 860 struct iio_dev_attr *p, *n; 861 862 list_for_each_entry_safe(p, n, attr_list, l) { 863 kfree(p->dev_attr.attr.name); 864 list_del(&p->l); 865 kfree(p); 866 } 867 } 868 869 static ssize_t iio_show_dev_name(struct device *dev, 870 struct device_attribute *attr, 871 char *buf) 872 { 873 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 874 return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name); 875 } 876 877 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL); 878 879 static int iio_device_register_sysfs(struct iio_dev *indio_dev) 880 { 881 int i, ret = 0, attrcount, attrn, attrcount_orig = 0; 882 struct iio_dev_attr *p; 883 struct attribute **attr; 884 885 /* First count elements in any existing group */ 886 if (indio_dev->info->attrs) { 887 attr = indio_dev->info->attrs->attrs; 888 while (*attr++ != NULL) 889 attrcount_orig++; 890 } 891 attrcount = attrcount_orig; 892 /* 893 * New channel registration method - relies on the fact a group does 894 * not need to be initialized if its name is NULL. 895 */ 896 if (indio_dev->channels) 897 for (i = 0; i < indio_dev->num_channels; i++) { 898 ret = iio_device_add_channel_sysfs(indio_dev, 899 &indio_dev 900 ->channels[i]); 901 if (ret < 0) 902 goto error_clear_attrs; 903 attrcount += ret; 904 } 905 906 if (indio_dev->name) 907 attrcount++; 908 909 indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1, 910 sizeof(indio_dev->chan_attr_group.attrs[0]), 911 GFP_KERNEL); 912 if (indio_dev->chan_attr_group.attrs == NULL) { 913 ret = -ENOMEM; 914 goto error_clear_attrs; 915 } 916 /* Copy across original attributes */ 917 if (indio_dev->info->attrs) 918 memcpy(indio_dev->chan_attr_group.attrs, 919 indio_dev->info->attrs->attrs, 920 sizeof(indio_dev->chan_attr_group.attrs[0]) 921 *attrcount_orig); 922 attrn = attrcount_orig; 923 /* Add all elements from the list. */ 924 list_for_each_entry(p, &indio_dev->channel_attr_list, l) 925 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr; 926 if (indio_dev->name) 927 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr; 928 929 indio_dev->groups[indio_dev->groupcounter++] = 930 &indio_dev->chan_attr_group; 931 932 return 0; 933 934 error_clear_attrs: 935 iio_free_chan_devattr_list(&indio_dev->channel_attr_list); 936 937 return ret; 938 } 939 940 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev) 941 { 942 943 iio_free_chan_devattr_list(&indio_dev->channel_attr_list); 944 kfree(indio_dev->chan_attr_group.attrs); 945 indio_dev->chan_attr_group.attrs = NULL; 946 } 947 948 static void iio_dev_release(struct device *device) 949 { 950 struct iio_dev *indio_dev = dev_to_iio_dev(device); 951 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) 952 iio_device_unregister_trigger_consumer(indio_dev); 953 iio_device_unregister_eventset(indio_dev); 954 iio_device_unregister_sysfs(indio_dev); 955 956 iio_buffer_put(indio_dev->buffer); 957 958 ida_simple_remove(&iio_ida, indio_dev->id); 959 kfree(indio_dev); 960 } 961 962 struct device_type iio_device_type = { 963 .name = "iio_device", 964 .release = iio_dev_release, 965 }; 966 967 /** 968 * iio_device_alloc() - allocate an iio_dev from a driver 969 * @sizeof_priv: Space to allocate for private structure. 970 **/ 971 struct iio_dev *iio_device_alloc(int sizeof_priv) 972 { 973 struct iio_dev *dev; 974 size_t alloc_size; 975 976 alloc_size = sizeof(struct iio_dev); 977 if (sizeof_priv) { 978 alloc_size = ALIGN(alloc_size, IIO_ALIGN); 979 alloc_size += sizeof_priv; 980 } 981 /* ensure 32-byte alignment of whole construct ? */ 982 alloc_size += IIO_ALIGN - 1; 983 984 dev = kzalloc(alloc_size, GFP_KERNEL); 985 986 if (dev) { 987 dev->dev.groups = dev->groups; 988 dev->dev.type = &iio_device_type; 989 dev->dev.bus = &iio_bus_type; 990 device_initialize(&dev->dev); 991 dev_set_drvdata(&dev->dev, (void *)dev); 992 mutex_init(&dev->mlock); 993 mutex_init(&dev->info_exist_lock); 994 INIT_LIST_HEAD(&dev->channel_attr_list); 995 996 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL); 997 if (dev->id < 0) { 998 /* cannot use a dev_err as the name isn't available */ 999 pr_err("failed to get device id\n"); 1000 kfree(dev); 1001 return NULL; 1002 } 1003 dev_set_name(&dev->dev, "iio:device%d", dev->id); 1004 INIT_LIST_HEAD(&dev->buffer_list); 1005 } 1006 1007 return dev; 1008 } 1009 EXPORT_SYMBOL(iio_device_alloc); 1010 1011 /** 1012 * iio_device_free() - free an iio_dev from a driver 1013 * @dev: the iio_dev associated with the device 1014 **/ 1015 void iio_device_free(struct iio_dev *dev) 1016 { 1017 if (dev) 1018 put_device(&dev->dev); 1019 } 1020 EXPORT_SYMBOL(iio_device_free); 1021 1022 static void devm_iio_device_release(struct device *dev, void *res) 1023 { 1024 iio_device_free(*(struct iio_dev **)res); 1025 } 1026 1027 static int devm_iio_device_match(struct device *dev, void *res, void *data) 1028 { 1029 struct iio_dev **r = res; 1030 if (!r || !*r) { 1031 WARN_ON(!r || !*r); 1032 return 0; 1033 } 1034 return *r == data; 1035 } 1036 1037 /** 1038 * devm_iio_device_alloc - Resource-managed iio_device_alloc() 1039 * @dev: Device to allocate iio_dev for 1040 * @sizeof_priv: Space to allocate for private structure. 1041 * 1042 * Managed iio_device_alloc. iio_dev allocated with this function is 1043 * automatically freed on driver detach. 1044 * 1045 * If an iio_dev allocated with this function needs to be freed separately, 1046 * devm_iio_device_free() must be used. 1047 * 1048 * RETURNS: 1049 * Pointer to allocated iio_dev on success, NULL on failure. 1050 */ 1051 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv) 1052 { 1053 struct iio_dev **ptr, *iio_dev; 1054 1055 ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr), 1056 GFP_KERNEL); 1057 if (!ptr) 1058 return NULL; 1059 1060 iio_dev = iio_device_alloc(sizeof_priv); 1061 if (iio_dev) { 1062 *ptr = iio_dev; 1063 devres_add(dev, ptr); 1064 } else { 1065 devres_free(ptr); 1066 } 1067 1068 return iio_dev; 1069 } 1070 EXPORT_SYMBOL_GPL(devm_iio_device_alloc); 1071 1072 /** 1073 * devm_iio_device_free - Resource-managed iio_device_free() 1074 * @dev: Device this iio_dev belongs to 1075 * @iio_dev: the iio_dev associated with the device 1076 * 1077 * Free iio_dev allocated with devm_iio_device_alloc(). 1078 */ 1079 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev) 1080 { 1081 int rc; 1082 1083 rc = devres_release(dev, devm_iio_device_release, 1084 devm_iio_device_match, iio_dev); 1085 WARN_ON(rc); 1086 } 1087 EXPORT_SYMBOL_GPL(devm_iio_device_free); 1088 1089 /** 1090 * iio_chrdev_open() - chrdev file open for buffer access and ioctls 1091 **/ 1092 static int iio_chrdev_open(struct inode *inode, struct file *filp) 1093 { 1094 struct iio_dev *indio_dev = container_of(inode->i_cdev, 1095 struct iio_dev, chrdev); 1096 1097 if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags)) 1098 return -EBUSY; 1099 1100 iio_device_get(indio_dev); 1101 1102 filp->private_data = indio_dev; 1103 1104 return 0; 1105 } 1106 1107 /** 1108 * iio_chrdev_release() - chrdev file close buffer access and ioctls 1109 **/ 1110 static int iio_chrdev_release(struct inode *inode, struct file *filp) 1111 { 1112 struct iio_dev *indio_dev = container_of(inode->i_cdev, 1113 struct iio_dev, chrdev); 1114 clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags); 1115 iio_device_put(indio_dev); 1116 1117 return 0; 1118 } 1119 1120 /* Somewhat of a cross file organization violation - ioctls here are actually 1121 * event related */ 1122 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 1123 { 1124 struct iio_dev *indio_dev = filp->private_data; 1125 int __user *ip = (int __user *)arg; 1126 int fd; 1127 1128 if (!indio_dev->info) 1129 return -ENODEV; 1130 1131 if (cmd == IIO_GET_EVENT_FD_IOCTL) { 1132 fd = iio_event_getfd(indio_dev); 1133 if (copy_to_user(ip, &fd, sizeof(fd))) 1134 return -EFAULT; 1135 return 0; 1136 } 1137 return -EINVAL; 1138 } 1139 1140 static const struct file_operations iio_buffer_fileops = { 1141 .read = iio_buffer_read_first_n_outer_addr, 1142 .release = iio_chrdev_release, 1143 .open = iio_chrdev_open, 1144 .poll = iio_buffer_poll_addr, 1145 .owner = THIS_MODULE, 1146 .llseek = noop_llseek, 1147 .unlocked_ioctl = iio_ioctl, 1148 .compat_ioctl = iio_ioctl, 1149 }; 1150 1151 static int iio_check_unique_scan_index(struct iio_dev *indio_dev) 1152 { 1153 int i, j; 1154 const struct iio_chan_spec *channels = indio_dev->channels; 1155 1156 if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES)) 1157 return 0; 1158 1159 for (i = 0; i < indio_dev->num_channels - 1; i++) { 1160 if (channels[i].scan_index < 0) 1161 continue; 1162 for (j = i + 1; j < indio_dev->num_channels; j++) 1163 if (channels[i].scan_index == channels[j].scan_index) { 1164 dev_err(&indio_dev->dev, 1165 "Duplicate scan index %d\n", 1166 channels[i].scan_index); 1167 return -EINVAL; 1168 } 1169 } 1170 1171 return 0; 1172 } 1173 1174 static const struct iio_buffer_setup_ops noop_ring_setup_ops; 1175 1176 /** 1177 * iio_device_register() - register a device with the IIO subsystem 1178 * @indio_dev: Device structure filled by the device driver 1179 **/ 1180 int iio_device_register(struct iio_dev *indio_dev) 1181 { 1182 int ret; 1183 1184 /* If the calling driver did not initialize of_node, do it here */ 1185 if (!indio_dev->dev.of_node && indio_dev->dev.parent) 1186 indio_dev->dev.of_node = indio_dev->dev.parent->of_node; 1187 1188 ret = iio_check_unique_scan_index(indio_dev); 1189 if (ret < 0) 1190 return ret; 1191 1192 /* configure elements for the chrdev */ 1193 indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id); 1194 1195 ret = iio_device_register_debugfs(indio_dev); 1196 if (ret) { 1197 dev_err(indio_dev->dev.parent, 1198 "Failed to register debugfs interfaces\n"); 1199 return ret; 1200 } 1201 1202 ret = iio_buffer_alloc_sysfs_and_mask(indio_dev); 1203 if (ret) { 1204 dev_err(indio_dev->dev.parent, 1205 "Failed to create buffer sysfs interfaces\n"); 1206 goto error_unreg_debugfs; 1207 } 1208 1209 ret = iio_device_register_sysfs(indio_dev); 1210 if (ret) { 1211 dev_err(indio_dev->dev.parent, 1212 "Failed to register sysfs interfaces\n"); 1213 goto error_buffer_free_sysfs; 1214 } 1215 ret = iio_device_register_eventset(indio_dev); 1216 if (ret) { 1217 dev_err(indio_dev->dev.parent, 1218 "Failed to register event set\n"); 1219 goto error_free_sysfs; 1220 } 1221 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) 1222 iio_device_register_trigger_consumer(indio_dev); 1223 1224 if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) && 1225 indio_dev->setup_ops == NULL) 1226 indio_dev->setup_ops = &noop_ring_setup_ops; 1227 1228 cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); 1229 indio_dev->chrdev.owner = indio_dev->info->driver_module; 1230 indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj; 1231 ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1); 1232 if (ret < 0) 1233 goto error_unreg_eventset; 1234 1235 ret = device_add(&indio_dev->dev); 1236 if (ret < 0) 1237 goto error_cdev_del; 1238 1239 return 0; 1240 error_cdev_del: 1241 cdev_del(&indio_dev->chrdev); 1242 error_unreg_eventset: 1243 iio_device_unregister_eventset(indio_dev); 1244 error_free_sysfs: 1245 iio_device_unregister_sysfs(indio_dev); 1246 error_buffer_free_sysfs: 1247 iio_buffer_free_sysfs_and_mask(indio_dev); 1248 error_unreg_debugfs: 1249 iio_device_unregister_debugfs(indio_dev); 1250 return ret; 1251 } 1252 EXPORT_SYMBOL(iio_device_register); 1253 1254 /** 1255 * iio_device_unregister() - unregister a device from the IIO subsystem 1256 * @indio_dev: Device structure representing the device. 1257 **/ 1258 void iio_device_unregister(struct iio_dev *indio_dev) 1259 { 1260 mutex_lock(&indio_dev->info_exist_lock); 1261 1262 device_del(&indio_dev->dev); 1263 1264 if (indio_dev->chrdev.dev) 1265 cdev_del(&indio_dev->chrdev); 1266 iio_device_unregister_debugfs(indio_dev); 1267 1268 iio_disable_all_buffers(indio_dev); 1269 1270 indio_dev->info = NULL; 1271 1272 iio_device_wakeup_eventset(indio_dev); 1273 iio_buffer_wakeup_poll(indio_dev); 1274 1275 mutex_unlock(&indio_dev->info_exist_lock); 1276 1277 iio_buffer_free_sysfs_and_mask(indio_dev); 1278 } 1279 EXPORT_SYMBOL(iio_device_unregister); 1280 1281 static void devm_iio_device_unreg(struct device *dev, void *res) 1282 { 1283 iio_device_unregister(*(struct iio_dev **)res); 1284 } 1285 1286 /** 1287 * devm_iio_device_register - Resource-managed iio_device_register() 1288 * @dev: Device to allocate iio_dev for 1289 * @indio_dev: Device structure filled by the device driver 1290 * 1291 * Managed iio_device_register. The IIO device registered with this 1292 * function is automatically unregistered on driver detach. This function 1293 * calls iio_device_register() internally. Refer to that function for more 1294 * information. 1295 * 1296 * If an iio_dev registered with this function needs to be unregistered 1297 * separately, devm_iio_device_unregister() must be used. 1298 * 1299 * RETURNS: 1300 * 0 on success, negative error number on failure. 1301 */ 1302 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev) 1303 { 1304 struct iio_dev **ptr; 1305 int ret; 1306 1307 ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL); 1308 if (!ptr) 1309 return -ENOMEM; 1310 1311 *ptr = indio_dev; 1312 ret = iio_device_register(indio_dev); 1313 if (!ret) 1314 devres_add(dev, ptr); 1315 else 1316 devres_free(ptr); 1317 1318 return ret; 1319 } 1320 EXPORT_SYMBOL_GPL(devm_iio_device_register); 1321 1322 /** 1323 * devm_iio_device_unregister - Resource-managed iio_device_unregister() 1324 * @dev: Device this iio_dev belongs to 1325 * @indio_dev: the iio_dev associated with the device 1326 * 1327 * Unregister iio_dev registered with devm_iio_device_register(). 1328 */ 1329 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev) 1330 { 1331 int rc; 1332 1333 rc = devres_release(dev, devm_iio_device_unreg, 1334 devm_iio_device_match, indio_dev); 1335 WARN_ON(rc); 1336 } 1337 EXPORT_SYMBOL_GPL(devm_iio_device_unregister); 1338 1339 subsys_initcall(iio_init); 1340 module_exit(iio_exit); 1341 1342 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>"); 1343 MODULE_DESCRIPTION("Industrial I/O core"); 1344 MODULE_LICENSE("GPL"); 1345