drivers/iio/industrialio-core.c

   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", &reg, &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");