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