drivers/iio/industrialio-core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* The industrial I/O core
   3  *
   4  * Copyright (c) 2008 Jonathan Cameron
   5  *
   6  * Based on elements of hwmon and input subsystems.
   7  */
   8
   9 #define pr_fmt(fmt) "iio-core: " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/idr.h>
  14 #include <linux/kdev_t.h>
  15 #include <linux/err.h>
  16 #include <linux/device.h>
  17 #include <linux/fs.h>
  18 #include <linux/poll.h>
  19 #include <linux/property.h>
  20 #include <linux/sched.h>
  21 #include <linux/wait.h>
  22 #include <linux/cdev.h>
  23 #include <linux/slab.h>
  24 #include <linux/anon_inodes.h>
  25 #include <linux/debugfs.h>
  26 #include <linux/mutex.h>
  27 #include <linux/iio/iio.h>
  28 #include <linux/iio/iio-opaque.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 #include <linux/iio/buffer_impl.h>
  35
  36 /* IDA to assign each registered device a unique id */
  37 static DEFINE_IDA(iio_ida);
  38
  39 static dev_t iio_devt;
  40
  41 #define IIO_DEV_MAX 256
  42 struct bus_type iio_bus_type = {
  43         .name = "iio",
  44 };
  45 EXPORT_SYMBOL(iio_bus_type);
  46
  47 static struct dentry *iio_debugfs_dentry;
  48
  49 static const char * const iio_direction[] = {
  50         [0] = "in",
  51         [1] = "out",
  52 };
  53
  54 static const char * const iio_chan_type_name_spec[] = {
  55         [IIO_VOLTAGE] = "voltage",
  56         [IIO_CURRENT] = "current",
  57         [IIO_POWER] = "power",
  58         [IIO_ACCEL] = "accel",
  59         [IIO_ANGL_VEL] = "anglvel",
  60         [IIO_MAGN] = "magn",
  61         [IIO_LIGHT] = "illuminance",
  62         [IIO_INTENSITY] = "intensity",
  63         [IIO_PROXIMITY] = "proximity",
  64         [IIO_TEMP] = "temp",
  65         [IIO_INCLI] = "incli",
  66         [IIO_ROT] = "rot",
  67         [IIO_ANGL] = "angl",
  68         [IIO_TIMESTAMP] = "timestamp",
  69         [IIO_CAPACITANCE] = "capacitance",
  70         [IIO_ALTVOLTAGE] = "altvoltage",
  71         [IIO_CCT] = "cct",
  72         [IIO_PRESSURE] = "pressure",
  73         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  74         [IIO_ACTIVITY] = "activity",
  75         [IIO_STEPS] = "steps",
  76         [IIO_ENERGY] = "energy",
  77         [IIO_DISTANCE] = "distance",
  78         [IIO_VELOCITY] = "velocity",
  79         [IIO_CONCENTRATION] = "concentration",
  80         [IIO_RESISTANCE] = "resistance",
  81         [IIO_PH] = "ph",
  82         [IIO_UVINDEX] = "uvindex",
  83         [IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  84         [IIO_COUNT] = "count",
  85         [IIO_INDEX] = "index",
  86         [IIO_GRAVITY]  = "gravity",
  87         [IIO_POSITIONRELATIVE]  = "positionrelative",
  88         [IIO_PHASE] = "phase",
  89         [IIO_MASSCONCENTRATION] = "massconcentration",
  90 };
  91
  92 static const char * const iio_modifier_names[] = {
  93         [IIO_MOD_X] = "x",
  94         [IIO_MOD_Y] = "y",
  95         [IIO_MOD_Z] = "z",
  96         [IIO_MOD_X_AND_Y] = "x&y",
  97         [IIO_MOD_X_AND_Z] = "x&z",
  98         [IIO_MOD_Y_AND_Z] = "y&z",
  99         [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
 100         [IIO_MOD_X_OR_Y] = "x|y",
 101         [IIO_MOD_X_OR_Z] = "x|z",
 102         [IIO_MOD_Y_OR_Z] = "y|z",
 103         [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 104         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 105         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 106         [IIO_MOD_LIGHT_BOTH] = "both",
 107         [IIO_MOD_LIGHT_IR] = "ir",
 108         [IIO_MOD_LIGHT_CLEAR] = "clear",
 109         [IIO_MOD_LIGHT_RED] = "red",
 110         [IIO_MOD_LIGHT_GREEN] = "green",
 111         [IIO_MOD_LIGHT_BLUE] = "blue",
 112         [IIO_MOD_LIGHT_UV] = "uv",
 113         [IIO_MOD_LIGHT_DUV] = "duv",
 114         [IIO_MOD_QUATERNION] = "quaternion",
 115         [IIO_MOD_TEMP_AMBIENT] = "ambient",
 116         [IIO_MOD_TEMP_OBJECT] = "object",
 117         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 118         [IIO_MOD_NORTH_TRUE] = "from_north_true",
 119         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 120         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 121         [IIO_MOD_RUNNING] = "running",
 122         [IIO_MOD_JOGGING] = "jogging",
 123         [IIO_MOD_WALKING] = "walking",
 124         [IIO_MOD_STILL] = "still",
 125         [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 126         [IIO_MOD_I] = "i",
 127         [IIO_MOD_Q] = "q",
 128         [IIO_MOD_CO2] = "co2",
 129         [IIO_MOD_VOC] = "voc",
 130         [IIO_MOD_PM1] = "pm1",
 131         [IIO_MOD_PM2P5] = "pm2p5",
 132         [IIO_MOD_PM4] = "pm4",
 133         [IIO_MOD_PM10] = "pm10",
 134         [IIO_MOD_ETHANOL] = "ethanol",
 135         [IIO_MOD_H2] = "h2",
 136         [IIO_MOD_O2] = "o2",
 137 };
 138
 139 /* relies on pairs of these shared then separate */
 140 static const char * const iio_chan_info_postfix[] = {
 141         [IIO_CHAN_INFO_RAW] = "raw",
 142         [IIO_CHAN_INFO_PROCESSED] = "input",
 143         [IIO_CHAN_INFO_SCALE] = "scale",
 144         [IIO_CHAN_INFO_OFFSET] = "offset",
 145         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 146         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 147         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 148         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 149         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 150         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 151         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 152         = "filter_low_pass_3db_frequency",
 153         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 154         = "filter_high_pass_3db_frequency",
 155         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 156         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 157         [IIO_CHAN_INFO_PHASE] = "phase",
 158         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 159         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 160         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 161         [IIO_CHAN_INFO_ENABLE] = "en",
 162         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 163         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 164         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 165         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 166         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 167         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 168         [IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
 169         [IIO_CHAN_INFO_CALIBAMBIENT] = "calibambient",
 170 };
 171
 172 #if defined(CONFIG_DEBUG_FS)
 173 /*
 174  * There's also a CONFIG_DEBUG_FS guard in include/linux/iio/iio.h for
 175  * iio_get_debugfs_dentry() to make it inline if CONFIG_DEBUG_FS is undefined
 176  */
 177 struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev)
 178 {
 179         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 180         return iio_dev_opaque->debugfs_dentry;
 181 }
 182 EXPORT_SYMBOL_GPL(iio_get_debugfs_dentry);
 183 #endif
 184
 185 /**
 186  * iio_find_channel_from_si() - get channel from its scan index
 187  * @indio_dev:          device
 188  * @si:                 scan index to match
 189  */
 190 const struct iio_chan_spec
 191 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 192 {
 193         int i;
 194
 195         for (i = 0; i < indio_dev->num_channels; i++)
 196                 if (indio_dev->channels[i].scan_index == si)
 197                         return &indio_dev->channels[i];
 198         return NULL;
 199 }
 200
 201 /* This turns up an awful lot */
 202 ssize_t iio_read_const_attr(struct device *dev,
 203                             struct device_attribute *attr,
 204                             char *buf)
 205 {
 206         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 207 }
 208 EXPORT_SYMBOL(iio_read_const_attr);
 209
 210 /**
 211  * iio_device_set_clock() - Set current timestamping clock for the device
 212  * @indio_dev: IIO device structure containing the device
 213  * @clock_id: timestamping clock posix identifier to set.
 214  */
 215 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 216 {
 217         int ret;
 218         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 219         const struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
 220
 221         ret = mutex_lock_interruptible(&indio_dev->mlock);
 222         if (ret)
 223                 return ret;
 224         if ((ev_int && iio_event_enabled(ev_int)) ||
 225             iio_buffer_enabled(indio_dev)) {
 226                 mutex_unlock(&indio_dev->mlock);
 227                 return -EBUSY;
 228         }
 229         indio_dev->clock_id = clock_id;
 230         mutex_unlock(&indio_dev->mlock);
 231
 232         return 0;
 233 }
 234 EXPORT_SYMBOL(iio_device_set_clock);
 235
 236 /**
 237  * iio_get_time_ns() - utility function to get a time stamp for events etc
 238  * @indio_dev: device
 239  */
 240 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 241 {
 242         struct timespec64 tp;
 243
 244         switch (iio_device_get_clock(indio_dev)) {
 245         case CLOCK_REALTIME:
 246                 return ktime_get_real_ns();
 247         case CLOCK_MONOTONIC:
 248                 return ktime_get_ns();
 249         case CLOCK_MONOTONIC_RAW:
 250                 return ktime_get_raw_ns();
 251         case CLOCK_REALTIME_COARSE:
 252                 return ktime_to_ns(ktime_get_coarse_real());
 253         case CLOCK_MONOTONIC_COARSE:
 254                 ktime_get_coarse_ts64(&tp);
 255                 return timespec64_to_ns(&tp);
 256         case CLOCK_BOOTTIME:
 257                 return ktime_get_boottime_ns();
 258         case CLOCK_TAI:
 259                 return ktime_get_clocktai_ns();
 260         default:
 261                 BUG();
 262         }
 263 }
 264 EXPORT_SYMBOL(iio_get_time_ns);
 265
 266 /**
 267  * iio_get_time_res() - utility function to get time stamp clock resolution in
 268  *                      nano seconds.
 269  * @indio_dev: device
 270  */
 271 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 272 {
 273         switch (iio_device_get_clock(indio_dev)) {
 274         case CLOCK_REALTIME:
 275         case CLOCK_MONOTONIC:
 276         case CLOCK_MONOTONIC_RAW:
 277         case CLOCK_BOOTTIME:
 278         case CLOCK_TAI:
 279                 return hrtimer_resolution;
 280         case CLOCK_REALTIME_COARSE:
 281         case CLOCK_MONOTONIC_COARSE:
 282                 return LOW_RES_NSEC;
 283         default:
 284                 BUG();
 285         }
 286 }
 287 EXPORT_SYMBOL(iio_get_time_res);
 288
 289 static int __init iio_init(void)
 290 {
 291         int ret;
 292
 293         /* Register sysfs bus */
 294         ret  = bus_register(&iio_bus_type);
 295         if (ret < 0) {
 296                 pr_err("could not register bus type\n");
 297                 goto error_nothing;
 298         }
 299
 300         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 301         if (ret < 0) {
 302                 pr_err("failed to allocate char dev region\n");
 303                 goto error_unregister_bus_type;
 304         }
 305
 306         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 307
 308         return 0;
 309
 310 error_unregister_bus_type:
 311         bus_unregister(&iio_bus_type);
 312 error_nothing:
 313         return ret;
 314 }
 315
 316 static void __exit iio_exit(void)
 317 {
 318         if (iio_devt)
 319                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 320         bus_unregister(&iio_bus_type);
 321         debugfs_remove(iio_debugfs_dentry);
 322 }
 323
 324 #if defined(CONFIG_DEBUG_FS)
 325 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 326                               size_t count, loff_t *ppos)
 327 {
 328         struct iio_dev *indio_dev = file->private_data;
 329         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 330         unsigned val = 0;
 331         int ret;
 332
 333         if (*ppos > 0)
 334                 return simple_read_from_buffer(userbuf, count, ppos,
 335                                                iio_dev_opaque->read_buf,
 336                                                iio_dev_opaque->read_buf_len);
 337
 338         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 339                                                   iio_dev_opaque->cached_reg_addr,
 340                                                   0, &val);
 341         if (ret) {
 342                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 343                 return ret;
 344         }
 345
 346         iio_dev_opaque->read_buf_len = snprintf(iio_dev_opaque->read_buf,
 347                                               sizeof(iio_dev_opaque->read_buf),
 348                                               "0x%X\n", val);
 349
 350         return simple_read_from_buffer(userbuf, count, ppos,
 351                                        iio_dev_opaque->read_buf,
 352                                        iio_dev_opaque->read_buf_len);
 353 }
 354
 355 static ssize_t iio_debugfs_write_reg(struct file *file,
 356                      const char __user *userbuf, size_t count, loff_t *ppos)
 357 {
 358         struct iio_dev *indio_dev = file->private_data;
 359         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 360         unsigned reg, val;
 361         char buf[80];
 362         int ret;
 363
 364         count = min_t(size_t, count, (sizeof(buf)-1));
 365         if (copy_from_user(buf, userbuf, count))
 366                 return -EFAULT;
 367
 368         buf[count] = 0;
 369
 370         ret = sscanf(buf, "%i %i", &reg, &val);
 371
 372         switch (ret) {
 373         case 1:
 374                 iio_dev_opaque->cached_reg_addr = reg;
 375                 break;
 376         case 2:
 377                 iio_dev_opaque->cached_reg_addr = reg;
 378                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 379                                                           val, NULL);
 380                 if (ret) {
 381                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 382                                 __func__);
 383                         return ret;
 384                 }
 385                 break;
 386         default:
 387                 return -EINVAL;
 388         }
 389
 390         return count;
 391 }
 392
 393 static const struct file_operations iio_debugfs_reg_fops = {
 394         .open = simple_open,
 395         .read = iio_debugfs_read_reg,
 396         .write = iio_debugfs_write_reg,
 397 };
 398
 399 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 400 {
 401         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 402         debugfs_remove_recursive(iio_dev_opaque->debugfs_dentry);
 403 }
 404
 405 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 406 {
 407         struct iio_dev_opaque *iio_dev_opaque;
 408
 409         if (indio_dev->info->debugfs_reg_access == NULL)
 410                 return;
 411
 412         if (!iio_debugfs_dentry)
 413                 return;
 414
 415         iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 416
 417         iio_dev_opaque->debugfs_dentry =
 418                 debugfs_create_dir(dev_name(&indio_dev->dev),
 419                                    iio_debugfs_dentry);
 420
 421         debugfs_create_file("direct_reg_access", 0644,
 422                             iio_dev_opaque->debugfs_dentry, indio_dev,
 423                             &iio_debugfs_reg_fops);
 424 }
 425 #else
 426 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 427 {
 428 }
 429
 430 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 431 {
 432 }
 433 #endif /* CONFIG_DEBUG_FS */
 434
 435 static ssize_t iio_read_channel_ext_info(struct device *dev,
 436                                      struct device_attribute *attr,
 437                                      char *buf)
 438 {
 439         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 440         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 441         const struct iio_chan_spec_ext_info *ext_info;
 442
 443         ext_info = &this_attr->c->ext_info[this_attr->address];
 444
 445         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 446 }
 447
 448 static ssize_t iio_write_channel_ext_info(struct device *dev,
 449                                      struct device_attribute *attr,
 450                                      const char *buf,
 451                                          size_t len)
 452 {
 453         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 454         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 455         const struct iio_chan_spec_ext_info *ext_info;
 456
 457         ext_info = &this_attr->c->ext_info[this_attr->address];
 458
 459         return ext_info->write(indio_dev, ext_info->private,
 460                                this_attr->c, buf, len);
 461 }
 462
 463 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 464         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 465 {
 466         const struct iio_enum *e = (const struct iio_enum *)priv;
 467         unsigned int i;
 468         size_t len = 0;
 469
 470         if (!e->num_items)
 471                 return 0;
 472
 473         for (i = 0; i < e->num_items; ++i)
 474                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 475
 476         /* replace last space with a newline */
 477         buf[len - 1] = '\n';
 478
 479         return len;
 480 }
 481 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 482
 483 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 484         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 485 {
 486         const struct iio_enum *e = (const struct iio_enum *)priv;
 487         int i;
 488
 489         if (!e->get)
 490                 return -EINVAL;
 491
 492         i = e->get(indio_dev, chan);
 493         if (i < 0)
 494                 return i;
 495         else if (i >= e->num_items)
 496                 return -EINVAL;
 497
 498         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 499 }
 500 EXPORT_SYMBOL_GPL(iio_enum_read);
 501
 502 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 503         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 504         size_t len)
 505 {
 506         const struct iio_enum *e = (const struct iio_enum *)priv;
 507         int ret;
 508
 509         if (!e->set)
 510                 return -EINVAL;
 511
 512         ret = __sysfs_match_string(e->items, e->num_items, buf);
 513         if (ret < 0)
 514                 return ret;
 515
 516         ret = e->set(indio_dev, chan, ret);
 517         return ret ? ret : len;
 518 }
 519 EXPORT_SYMBOL_GPL(iio_enum_write);
 520
 521 static const struct iio_mount_matrix iio_mount_idmatrix = {
 522         .rotation = {
 523                 "1", "0", "0",
 524                 "0", "1", "0",
 525                 "0", "0", "1"
 526         }
 527 };
 528
 529 static int iio_setup_mount_idmatrix(const struct device *dev,
 530                                     struct iio_mount_matrix *matrix)
 531 {
 532         *matrix = iio_mount_idmatrix;
 533         dev_info(dev, "mounting matrix not found: using identity...\n");
 534         return 0;
 535 }
 536
 537 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 538                               const struct iio_chan_spec *chan, char *buf)
 539 {
 540         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 541                                               priv)(indio_dev, chan);
 542
 543         if (IS_ERR(mtx))
 544                 return PTR_ERR(mtx);
 545
 546         if (!mtx)
 547                 mtx = &iio_mount_idmatrix;
 548
 549         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 550                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 551                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 552                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 553 }
 554 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 555
 556 /**
 557  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
 558  *                           device "mount-matrix" property
 559  * @dev:        device the mounting matrix property is assigned to
 560  * @propname:   device specific mounting matrix property name
 561  * @matrix:     where to store retrieved matrix
 562  *
 563  * If device is assigned no mounting matrix property, a default 3x3 identity
 564  * matrix will be filled in.
 565  *
 566  * Return: 0 if success, or a negative error code on failure.
 567  */
 568 int iio_read_mount_matrix(struct device *dev, const char *propname,
 569                           struct iio_mount_matrix *matrix)
 570 {
 571         size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
 572         int err;
 573
 574         err = device_property_read_string_array(dev, propname,
 575                                                 matrix->rotation, len);
 576         if (err == len)
 577                 return 0;
 578
 579         if (err >= 0)
 580                 /* Invalid number of matrix entries. */
 581                 return -EINVAL;
 582
 583         if (err != -EINVAL)
 584                 /* Invalid matrix declaration format. */
 585                 return err;
 586
 587         /* Matrix was not declared at all: fallback to identity. */
 588         return iio_setup_mount_idmatrix(dev, matrix);
 589 }
 590 EXPORT_SYMBOL(iio_read_mount_matrix);
 591
 592 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 593                                   int size, const int *vals)
 594 {
 595         unsigned long long tmp;
 596         int tmp0, tmp1;
 597         bool scale_db = false;
 598
 599         switch (type) {
 600         case IIO_VAL_INT:
 601                 return scnprintf(buf, len, "%d", vals[0]);
 602         case IIO_VAL_INT_PLUS_MICRO_DB:
 603                 scale_db = true;
 604                 fallthrough;
 605         case IIO_VAL_INT_PLUS_MICRO:
 606                 if (vals[1] < 0)
 607                         return scnprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 608                                         -vals[1], scale_db ? " dB" : "");
 609                 else
 610                         return scnprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 611                                         scale_db ? " dB" : "");
 612         case IIO_VAL_INT_PLUS_NANO:
 613                 if (vals[1] < 0)
 614                         return scnprintf(buf, len, "-%d.%09u", abs(vals[0]),
 615                                         -vals[1]);
 616                 else
 617                         return scnprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 618         case IIO_VAL_FRACTIONAL:
 619                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 620                 tmp1 = vals[1];
 621                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 622                 return scnprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 623         case IIO_VAL_FRACTIONAL_LOG2:
 624                 tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 625                 tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 626                 return scnprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 627         case IIO_VAL_INT_MULTIPLE:
 628         {
 629                 int i;
 630                 int l = 0;
 631
 632                 for (i = 0; i < size; ++i) {
 633                         l += scnprintf(&buf[l], len - l, "%d ", vals[i]);
 634                         if (l >= len)
 635                                 break;
 636                 }
 637                 return l;
 638         }
 639         case IIO_VAL_CHAR:
 640                 return scnprintf(buf, len, "%c", (char)vals[0]);
 641         default:
 642                 return 0;
 643         }
 644 }
 645
 646 /**
 647  * iio_format_value() - Formats a IIO value into its string representation
 648  * @buf:        The buffer to which the formatted value gets written
 649  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 650  * @type:       One of the IIO_VAL_* constants. This decides how the val
 651  *              and val2 parameters are formatted.
 652  * @size:       Number of IIO value entries contained in vals
 653  * @vals:       Pointer to the values, exact meaning depends on the
 654  *              type parameter.
 655  *
 656  * Return: 0 by default, a negative number on failure or the
 657  *         total number of characters written for a type that belongs
 658  *         to the IIO_VAL_* constant.
 659  */
 660 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 661 {
 662         ssize_t len;
 663
 664         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 665         if (len >= PAGE_SIZE - 1)
 666                 return -EFBIG;
 667
 668         return len + sprintf(buf + len, "\n");
 669 }
 670 EXPORT_SYMBOL_GPL(iio_format_value);
 671
 672 static ssize_t iio_read_channel_info(struct device *dev,
 673                                      struct device_attribute *attr,
 674                                      char *buf)
 675 {
 676         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 677         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 678         int vals[INDIO_MAX_RAW_ELEMENTS];
 679         int ret;
 680         int val_len = 2;
 681
 682         if (indio_dev->info->read_raw_multi)
 683                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 684                                                         INDIO_MAX_RAW_ELEMENTS,
 685                                                         vals, &val_len,
 686                                                         this_attr->address);
 687         else
 688                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 689                                     &vals[0], &vals[1], this_attr->address);
 690
 691         if (ret < 0)
 692                 return ret;
 693
 694         return iio_format_value(buf, ret, val_len, vals);
 695 }
 696
 697 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 698                                      int type, int length)
 699 {
 700         int i;
 701         ssize_t len = 0;
 702
 703         switch (type) {
 704         case IIO_VAL_INT:
 705                 for (i = 0; i < length; i++) {
 706                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 707                                                   type, 1, &vals[i]);
 708                         if (len >= PAGE_SIZE)
 709                                 return -EFBIG;
 710                         if (i < length - 1)
 711                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 712                                                 " ");
 713                         else
 714                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 715                                                 "\n");
 716                         if (len >= PAGE_SIZE)
 717                                 return -EFBIG;
 718                 }
 719                 break;
 720         default:
 721                 for (i = 0; i < length / 2; i++) {
 722                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 723                                                   type, 2, &vals[i * 2]);
 724                         if (len >= PAGE_SIZE)
 725                                 return -EFBIG;
 726                         if (i < length / 2 - 1)
 727                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 728                                                 " ");
 729                         else
 730                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 731                                                 "\n");
 732                         if (len >= PAGE_SIZE)
 733                                 return -EFBIG;
 734                 }
 735         }
 736
 737         return len;
 738 }
 739
 740 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 741 {
 742         int i;
 743         ssize_t len;
 744
 745         len = snprintf(buf, PAGE_SIZE, "[");
 746         switch (type) {
 747         case IIO_VAL_INT:
 748                 for (i = 0; i < 3; i++) {
 749                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 750                                                   type, 1, &vals[i]);
 751                         if (len >= PAGE_SIZE)
 752                                 return -EFBIG;
 753                         if (i < 2)
 754                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 755                                                 " ");
 756                         else
 757                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 758                                                 "]\n");
 759                         if (len >= PAGE_SIZE)
 760                                 return -EFBIG;
 761                 }
 762                 break;
 763         default:
 764                 for (i = 0; i < 3; i++) {
 765                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 766                                                   type, 2, &vals[i * 2]);
 767                         if (len >= PAGE_SIZE)
 768                                 return -EFBIG;
 769                         if (i < 2)
 770                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 771                                                 " ");
 772                         else
 773                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 774                                                 "]\n");
 775                         if (len >= PAGE_SIZE)
 776                                 return -EFBIG;
 777                 }
 778         }
 779
 780         return len;
 781 }
 782
 783 static ssize_t iio_read_channel_info_avail(struct device *dev,
 784                                            struct device_attribute *attr,
 785                                            char *buf)
 786 {
 787         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 788         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 789         const int *vals;
 790         int ret;
 791         int length;
 792         int type;
 793
 794         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 795                                           &vals, &type, &length,
 796                                           this_attr->address);
 797
 798         if (ret < 0)
 799                 return ret;
 800         switch (ret) {
 801         case IIO_AVAIL_LIST:
 802                 return iio_format_avail_list(buf, vals, type, length);
 803         case IIO_AVAIL_RANGE:
 804                 return iio_format_avail_range(buf, vals, type);
 805         default:
 806                 return -EINVAL;
 807         }
 808 }
 809
 810 /**
 811  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
 812  * @str: The string to parse
 813  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 814  * @integer: The integer part of the number
 815  * @fract: The fractional part of the number
 816  * @scale_db: True if this should parse as dB
 817  *
 818  * Returns 0 on success, or a negative error code if the string could not be
 819  * parsed.
 820  */
 821 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
 822                                  int *integer, int *fract, bool scale_db)
 823 {
 824         int i = 0, f = 0;
 825         bool integer_part = true, negative = false;
 826
 827         if (fract_mult == 0) {
 828                 *fract = 0;
 829
 830                 return kstrtoint(str, 0, integer);
 831         }
 832
 833         if (str[0] == '-') {
 834                 negative = true;
 835                 str++;
 836         } else if (str[0] == '+') {
 837                 str++;
 838         }
 839
 840         while (*str) {
 841                 if ('0' <= *str && *str <= '9') {
 842                         if (integer_part) {
 843                                 i = i * 10 + *str - '0';
 844                         } else {
 845                                 f += fract_mult * (*str - '0');
 846                                 fract_mult /= 10;
 847                         }
 848                 } else if (*str == '\n') {
 849                         if (*(str + 1) == '\0')
 850                                 break;
 851                         else
 852                                 return -EINVAL;
 853                 } else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
 854                         /* Ignore the dB suffix */
 855                         str += sizeof(" dB") - 1;
 856                         continue;
 857                 } else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
 858                         /* Ignore the dB suffix */
 859                         str += sizeof("dB") - 1;
 860                         continue;
 861                 } else if (*str == '.' && integer_part) {
 862                         integer_part = false;
 863                 } else {
 864                         return -EINVAL;
 865                 }
 866                 str++;
 867         }
 868
 869         if (negative) {
 870                 if (i)
 871                         i = -i;
 872                 else
 873                         f = -f;
 874         }
 875
 876         *integer = i;
 877         *fract = f;
 878
 879         return 0;
 880 }
 881
 882 /**
 883  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 884  * @str: The string to parse
 885  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 886  * @integer: The integer part of the number
 887  * @fract: The fractional part of the number
 888  *
 889  * Returns 0 on success, or a negative error code if the string could not be
 890  * parsed.
 891  */
 892 int iio_str_to_fixpoint(const char *str, int fract_mult,
 893                         int *integer, int *fract)
 894 {
 895         return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
 896 }
 897 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 898
 899 static ssize_t iio_write_channel_info(struct device *dev,
 900                                       struct device_attribute *attr,
 901                                       const char *buf,
 902                                       size_t len)
 903 {
 904         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 905         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 906         int ret, fract_mult = 100000;
 907         int integer, fract = 0;
 908         bool is_char = false;
 909         bool scale_db = false;
 910
 911         /* Assumes decimal - precision based on number of digits */
 912         if (!indio_dev->info->write_raw)
 913                 return -EINVAL;
 914
 915         if (indio_dev->info->write_raw_get_fmt)
 916                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 917                         this_attr->c, this_attr->address)) {
 918                 case IIO_VAL_INT:
 919                         fract_mult = 0;
 920                         break;
 921                 case IIO_VAL_INT_PLUS_MICRO_DB:
 922                         scale_db = true;
 923                         fallthrough;
 924                 case IIO_VAL_INT_PLUS_MICRO:
 925                         fract_mult = 100000;
 926                         break;
 927                 case IIO_VAL_INT_PLUS_NANO:
 928                         fract_mult = 100000000;
 929                         break;
 930                 case IIO_VAL_CHAR:
 931                         is_char = true;
 932                         break;
 933                 default:
 934                         return -EINVAL;
 935                 }
 936
 937         if (is_char) {
 938                 char ch;
 939
 940                 if (sscanf(buf, "%c", &ch) != 1)
 941                         return -EINVAL;
 942                 integer = ch;
 943         } else {
 944                 ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
 945                                             scale_db);
 946                 if (ret)
 947                         return ret;
 948         }
 949
 950         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 951                                          integer, fract, this_attr->address);
 952         if (ret)
 953                 return ret;
 954
 955         return len;
 956 }
 957
 958 static
 959 int __iio_device_attr_init(struct device_attribute *dev_attr,
 960                            const char *postfix,
 961                            struct iio_chan_spec const *chan,
 962                            ssize_t (*readfunc)(struct device *dev,
 963                                                struct device_attribute *attr,
 964                                                char *buf),
 965                            ssize_t (*writefunc)(struct device *dev,
 966                                                 struct device_attribute *attr,
 967                                                 const char *buf,
 968                                                 size_t len),
 969                            enum iio_shared_by shared_by)
 970 {
 971         int ret = 0;
 972         char *name = NULL;
 973         char *full_postfix;
 974         sysfs_attr_init(&dev_attr->attr);
 975
 976         /* Build up postfix of <extend_name>_<modifier>_postfix */
 977         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 978                 if (chan->extend_name)
 979                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 980                                                  iio_modifier_names[chan
 981                                                                     ->channel2],
 982                                                  chan->extend_name,
 983                                                  postfix);
 984                 else
 985                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 986                                                  iio_modifier_names[chan
 987                                                                     ->channel2],
 988                                                  postfix);
 989         } else {
 990                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 991                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 992                 else
 993                         full_postfix = kasprintf(GFP_KERNEL,
 994                                                  "%s_%s",
 995                                                  chan->extend_name,
 996                                                  postfix);
 997         }
 998         if (full_postfix == NULL)
 999                 return -ENOMEM;
1000
1001         if (chan->differential) { /* Differential can not have modifier */
1002                 switch (shared_by) {
1003                 case IIO_SHARED_BY_ALL:
1004                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1005                         break;
1006                 case IIO_SHARED_BY_DIR:
1007                         name = kasprintf(GFP_KERNEL, "%s_%s",
1008                                                 iio_direction[chan->output],
1009                                                 full_postfix);
1010                         break;
1011                 case IIO_SHARED_BY_TYPE:
1012                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
1013                                             iio_direction[chan->output],
1014                                             iio_chan_type_name_spec[chan->type],
1015                                             iio_chan_type_name_spec[chan->type],
1016                                             full_postfix);
1017                         break;
1018                 case IIO_SEPARATE:
1019                         if (!chan->indexed) {
1020                                 WARN(1, "Differential channels must be indexed\n");
1021                                 ret = -EINVAL;
1022                                 goto error_free_full_postfix;
1023                         }
1024                         name = kasprintf(GFP_KERNEL,
1025                                             "%s_%s%d-%s%d_%s",
1026                                             iio_direction[chan->output],
1027                                             iio_chan_type_name_spec[chan->type],
1028                                             chan->channel,
1029                                             iio_chan_type_name_spec[chan->type],
1030                                             chan->channel2,
1031                                             full_postfix);
1032                         break;
1033                 }
1034         } else { /* Single ended */
1035                 switch (shared_by) {
1036                 case IIO_SHARED_BY_ALL:
1037                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1038                         break;
1039                 case IIO_SHARED_BY_DIR:
1040                         name = kasprintf(GFP_KERNEL, "%s_%s",
1041                                                 iio_direction[chan->output],
1042                                                 full_postfix);
1043                         break;
1044                 case IIO_SHARED_BY_TYPE:
1045                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1046                                             iio_direction[chan->output],
1047                                             iio_chan_type_name_spec[chan->type],
1048                                             full_postfix);
1049                         break;
1050
1051                 case IIO_SEPARATE:
1052                         if (chan->indexed)
1053                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1054                                                     iio_direction[chan->output],
1055                                                     iio_chan_type_name_spec[chan->type],
1056                                                     chan->channel,
1057                                                     full_postfix);
1058                         else
1059                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1060                                                     iio_direction[chan->output],
1061                                                     iio_chan_type_name_spec[chan->type],
1062                                                     full_postfix);
1063                         break;
1064                 }
1065         }
1066         if (name == NULL) {
1067                 ret = -ENOMEM;
1068                 goto error_free_full_postfix;
1069         }
1070         dev_attr->attr.name = name;
1071
1072         if (readfunc) {
1073                 dev_attr->attr.mode |= S_IRUGO;
1074                 dev_attr->show = readfunc;
1075         }
1076
1077         if (writefunc) {
1078                 dev_attr->attr.mode |= S_IWUSR;
1079                 dev_attr->store = writefunc;
1080         }
1081
1082 error_free_full_postfix:
1083         kfree(full_postfix);
1084
1085         return ret;
1086 }
1087
1088 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1089 {
1090         kfree(dev_attr->attr.name);
1091 }
1092
1093 int __iio_add_chan_devattr(const char *postfix,
1094                            struct iio_chan_spec const *chan,
1095                            ssize_t (*readfunc)(struct device *dev,
1096                                                struct device_attribute *attr,
1097                                                char *buf),
1098                            ssize_t (*writefunc)(struct device *dev,
1099                                                 struct device_attribute *attr,
1100                                                 const char *buf,
1101                                                 size_t len),
1102                            u64 mask,
1103                            enum iio_shared_by shared_by,
1104                            struct device *dev,
1105                            struct list_head *attr_list)
1106 {
1107         int ret;
1108         struct iio_dev_attr *iio_attr, *t;
1109
1110         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1111         if (iio_attr == NULL)
1112                 return -ENOMEM;
1113         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1114                                      postfix, chan,
1115                                      readfunc, writefunc, shared_by);
1116         if (ret)
1117                 goto error_iio_dev_attr_free;
1118         iio_attr->c = chan;
1119         iio_attr->address = mask;
1120         list_for_each_entry(t, attr_list, l)
1121                 if (strcmp(t->dev_attr.attr.name,
1122                            iio_attr->dev_attr.attr.name) == 0) {
1123                         if (shared_by == IIO_SEPARATE)
1124                                 dev_err(dev, "tried to double register : %s\n",
1125                                         t->dev_attr.attr.name);
1126                         ret = -EBUSY;
1127                         goto error_device_attr_deinit;
1128                 }
1129         list_add(&iio_attr->l, attr_list);
1130
1131         return 0;
1132
1133 error_device_attr_deinit:
1134         __iio_device_attr_deinit(&iio_attr->dev_attr);
1135 error_iio_dev_attr_free:
1136         kfree(iio_attr);
1137         return ret;
1138 }
1139
1140 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1141                                          struct iio_chan_spec const *chan,
1142                                          enum iio_shared_by shared_by,
1143                                          const long *infomask)
1144 {
1145         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1146         int i, ret, attrcount = 0;
1147
1148         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1149                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1150                         return -EINVAL;
1151                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1152                                              chan,
1153                                              &iio_read_channel_info,
1154                                              &iio_write_channel_info,
1155                                              i,
1156                                              shared_by,
1157                                              &indio_dev->dev,
1158                                              &iio_dev_opaque->channel_attr_list);
1159                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1160                         continue;
1161                 else if (ret < 0)
1162                         return ret;
1163                 attrcount++;
1164         }
1165
1166         return attrcount;
1167 }
1168
1169 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1170                                                struct iio_chan_spec const *chan,
1171                                                enum iio_shared_by shared_by,
1172                                                const long *infomask)
1173 {
1174         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1175         int i, ret, attrcount = 0;
1176         char *avail_postfix;
1177
1178         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1179                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1180                         return -EINVAL;
1181                 avail_postfix = kasprintf(GFP_KERNEL,
1182                                           "%s_available",
1183                                           iio_chan_info_postfix[i]);
1184                 if (!avail_postfix)
1185                         return -ENOMEM;
1186
1187                 ret = __iio_add_chan_devattr(avail_postfix,
1188                                              chan,
1189                                              &iio_read_channel_info_avail,
1190                                              NULL,
1191                                              i,
1192                                              shared_by,
1193                                              &indio_dev->dev,
1194                                              &iio_dev_opaque->channel_attr_list);
1195                 kfree(avail_postfix);
1196                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1197                         continue;
1198                 else if (ret < 0)
1199                         return ret;
1200                 attrcount++;
1201         }
1202
1203         return attrcount;
1204 }
1205
1206 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1207                                         struct iio_chan_spec const *chan)
1208 {
1209         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1210         int ret, attrcount = 0;
1211         const struct iio_chan_spec_ext_info *ext_info;
1212
1213         if (chan->channel < 0)
1214                 return 0;
1215         ret = iio_device_add_info_mask_type(indio_dev, chan,
1216                                             IIO_SEPARATE,
1217                                             &chan->info_mask_separate);
1218         if (ret < 0)
1219                 return ret;
1220         attrcount += ret;
1221
1222         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1223                                                   IIO_SEPARATE,
1224                                                   &chan->
1225                                                   info_mask_separate_available);
1226         if (ret < 0)
1227                 return ret;
1228         attrcount += ret;
1229
1230         ret = iio_device_add_info_mask_type(indio_dev, chan,
1231                                             IIO_SHARED_BY_TYPE,
1232                                             &chan->info_mask_shared_by_type);
1233         if (ret < 0)
1234                 return ret;
1235         attrcount += ret;
1236
1237         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1238                                                   IIO_SHARED_BY_TYPE,
1239                                                   &chan->
1240                                                   info_mask_shared_by_type_available);
1241         if (ret < 0)
1242                 return ret;
1243         attrcount += ret;
1244
1245         ret = iio_device_add_info_mask_type(indio_dev, chan,
1246                                             IIO_SHARED_BY_DIR,
1247                                             &chan->info_mask_shared_by_dir);
1248         if (ret < 0)
1249                 return ret;
1250         attrcount += ret;
1251
1252         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1253                                                   IIO_SHARED_BY_DIR,
1254                                                   &chan->info_mask_shared_by_dir_available);
1255         if (ret < 0)
1256                 return ret;
1257         attrcount += ret;
1258
1259         ret = iio_device_add_info_mask_type(indio_dev, chan,
1260                                             IIO_SHARED_BY_ALL,
1261                                             &chan->info_mask_shared_by_all);
1262         if (ret < 0)
1263                 return ret;
1264         attrcount += ret;
1265
1266         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1267                                                   IIO_SHARED_BY_ALL,
1268                                                   &chan->info_mask_shared_by_all_available);
1269         if (ret < 0)
1270                 return ret;
1271         attrcount += ret;
1272
1273         if (chan->ext_info) {
1274                 unsigned int i = 0;
1275                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1276                         ret = __iio_add_chan_devattr(ext_info->name,
1277                                         chan,
1278                                         ext_info->read ?
1279                                             &iio_read_channel_ext_info : NULL,
1280                                         ext_info->write ?
1281                                             &iio_write_channel_ext_info : NULL,
1282                                         i,
1283                                         ext_info->shared,
1284                                         &indio_dev->dev,
1285                                         &iio_dev_opaque->channel_attr_list);
1286                         i++;
1287                         if (ret == -EBUSY && ext_info->shared)
1288                                 continue;
1289
1290                         if (ret)
1291                                 return ret;
1292
1293                         attrcount++;
1294                 }
1295         }
1296
1297         return attrcount;
1298 }
1299
1300 /**
1301  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1302  * @attr_list: List of IIO device attributes
1303  *
1304  * This function frees the memory allocated for each of the IIO device
1305  * attributes in the list.
1306  */
1307 void iio_free_chan_devattr_list(struct list_head *attr_list)
1308 {
1309         struct iio_dev_attr *p, *n;
1310
1311         list_for_each_entry_safe(p, n, attr_list, l) {
1312                 kfree(p->dev_attr.attr.name);
1313                 list_del(&p->l);
1314                 kfree(p);
1315         }
1316 }
1317
1318 static ssize_t iio_show_dev_name(struct device *dev,
1319                                  struct device_attribute *attr,
1320                                  char *buf)
1321 {
1322         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1323         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1324 }
1325
1326 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1327
1328 static ssize_t iio_show_dev_label(struct device *dev,
1329                                  struct device_attribute *attr,
1330                                  char *buf)
1331 {
1332         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1333         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
1334 }
1335
1336 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1337
1338 static ssize_t iio_show_timestamp_clock(struct device *dev,
1339                                         struct device_attribute *attr,
1340                                         char *buf)
1341 {
1342         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1343         const clockid_t clk = iio_device_get_clock(indio_dev);
1344         const char *name;
1345         ssize_t sz;
1346
1347         switch (clk) {
1348         case CLOCK_REALTIME:
1349                 name = "realtime\n";
1350                 sz = sizeof("realtime\n");
1351                 break;
1352         case CLOCK_MONOTONIC:
1353                 name = "monotonic\n";
1354                 sz = sizeof("monotonic\n");
1355                 break;
1356         case CLOCK_MONOTONIC_RAW:
1357                 name = "monotonic_raw\n";
1358                 sz = sizeof("monotonic_raw\n");
1359                 break;
1360         case CLOCK_REALTIME_COARSE:
1361                 name = "realtime_coarse\n";
1362                 sz = sizeof("realtime_coarse\n");
1363                 break;
1364         case CLOCK_MONOTONIC_COARSE:
1365                 name = "monotonic_coarse\n";
1366                 sz = sizeof("monotonic_coarse\n");
1367                 break;
1368         case CLOCK_BOOTTIME:
1369                 name = "boottime\n";
1370                 sz = sizeof("boottime\n");
1371                 break;
1372         case CLOCK_TAI:
1373                 name = "tai\n";
1374                 sz = sizeof("tai\n");
1375                 break;
1376         default:
1377                 BUG();
1378         }
1379
1380         memcpy(buf, name, sz);
1381         return sz;
1382 }
1383
1384 static ssize_t iio_store_timestamp_clock(struct device *dev,
1385                                          struct device_attribute *attr,
1386                                          const char *buf, size_t len)
1387 {
1388         clockid_t clk;
1389         int ret;
1390
1391         if (sysfs_streq(buf, "realtime"))
1392                 clk = CLOCK_REALTIME;
1393         else if (sysfs_streq(buf, "monotonic"))
1394                 clk = CLOCK_MONOTONIC;
1395         else if (sysfs_streq(buf, "monotonic_raw"))
1396                 clk = CLOCK_MONOTONIC_RAW;
1397         else if (sysfs_streq(buf, "realtime_coarse"))
1398                 clk = CLOCK_REALTIME_COARSE;
1399         else if (sysfs_streq(buf, "monotonic_coarse"))
1400                 clk = CLOCK_MONOTONIC_COARSE;
1401         else if (sysfs_streq(buf, "boottime"))
1402                 clk = CLOCK_BOOTTIME;
1403         else if (sysfs_streq(buf, "tai"))
1404                 clk = CLOCK_TAI;
1405         else
1406                 return -EINVAL;
1407
1408         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1409         if (ret)
1410                 return ret;
1411
1412         return len;
1413 }
1414
1415 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1416                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1417
1418 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1419 {
1420         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1421         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1422         struct iio_dev_attr *p;
1423         struct attribute **attr, *clk = NULL;
1424
1425         /* First count elements in any existing group */
1426         if (indio_dev->info->attrs) {
1427                 attr = indio_dev->info->attrs->attrs;
1428                 while (*attr++ != NULL)
1429                         attrcount_orig++;
1430         }
1431         attrcount = attrcount_orig;
1432         /*
1433          * New channel registration method - relies on the fact a group does
1434          * not need to be initialized if its name is NULL.
1435          */
1436         if (indio_dev->channels)
1437                 for (i = 0; i < indio_dev->num_channels; i++) {
1438                         const struct iio_chan_spec *chan =
1439                                 &indio_dev->channels[i];
1440
1441                         if (chan->type == IIO_TIMESTAMP)
1442                                 clk = &dev_attr_current_timestamp_clock.attr;
1443
1444                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1445                         if (ret < 0)
1446                                 goto error_clear_attrs;
1447                         attrcount += ret;
1448                 }
1449
1450         if (iio_dev_opaque->event_interface)
1451                 clk = &dev_attr_current_timestamp_clock.attr;
1452
1453         if (indio_dev->name)
1454                 attrcount++;
1455         if (indio_dev->label)
1456                 attrcount++;
1457         if (clk)
1458                 attrcount++;
1459
1460         iio_dev_opaque->chan_attr_group.attrs =
1461                 kcalloc(attrcount + 1,
1462                         sizeof(iio_dev_opaque->chan_attr_group.attrs[0]),
1463                         GFP_KERNEL);
1464         if (iio_dev_opaque->chan_attr_group.attrs == NULL) {
1465                 ret = -ENOMEM;
1466                 goto error_clear_attrs;
1467         }
1468         /* Copy across original attributes */
1469         if (indio_dev->info->attrs)
1470                 memcpy(iio_dev_opaque->chan_attr_group.attrs,
1471                        indio_dev->info->attrs->attrs,
1472                        sizeof(iio_dev_opaque->chan_attr_group.attrs[0])
1473                        *attrcount_orig);
1474         attrn = attrcount_orig;
1475         /* Add all elements from the list. */
1476         list_for_each_entry(p, &iio_dev_opaque->channel_attr_list, l)
1477                 iio_dev_opaque->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1478         if (indio_dev->name)
1479                 iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1480         if (indio_dev->label)
1481                 iio_dev_opaque->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1482         if (clk)
1483                 iio_dev_opaque->chan_attr_group.attrs[attrn++] = clk;
1484
1485         indio_dev->groups[indio_dev->groupcounter++] =
1486                 &iio_dev_opaque->chan_attr_group;
1487
1488         return 0;
1489
1490 error_clear_attrs:
1491         iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1492
1493         return ret;
1494 }
1495
1496 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1497 {
1498         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1499
1500         iio_free_chan_devattr_list(&iio_dev_opaque->channel_attr_list);
1501         kfree(iio_dev_opaque->chan_attr_group.attrs);
1502         iio_dev_opaque->chan_attr_group.attrs = NULL;
1503 }
1504
1505 static void iio_dev_release(struct device *device)
1506 {
1507         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1508         struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1509
1510         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1511                 iio_device_unregister_trigger_consumer(indio_dev);
1512         iio_device_unregister_eventset(indio_dev);
1513         iio_device_unregister_sysfs(indio_dev);
1514
1515         iio_buffer_put(indio_dev->buffer);
1516
1517         ida_simple_remove(&iio_ida, indio_dev->id);
1518         kfree(iio_dev_opaque);
1519 }
1520
1521 struct device_type iio_device_type = {
1522         .name = "iio_device",
1523         .release = iio_dev_release,
1524 };
1525
1526 /**
1527  * iio_device_alloc() - allocate an iio_dev from a driver
1528  * @parent:             Parent device.
1529  * @sizeof_priv:        Space to allocate for private structure.
1530  **/
1531 struct iio_dev *iio_device_alloc(struct device *parent, int sizeof_priv)
1532 {
1533         struct iio_dev_opaque *iio_dev_opaque;
1534         struct iio_dev *dev;
1535         size_t alloc_size;
1536
1537         alloc_size = sizeof(struct iio_dev_opaque);
1538         if (sizeof_priv) {
1539                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1540                 alloc_size += sizeof_priv;
1541         }
1542
1543         iio_dev_opaque = kzalloc(alloc_size, GFP_KERNEL);
1544         if (!iio_dev_opaque)
1545                 return NULL;
1546
1547         dev = &iio_dev_opaque->indio_dev;
1548         dev->priv = (char *)iio_dev_opaque +
1549                 ALIGN(sizeof(struct iio_dev_opaque), IIO_ALIGN);
1550
1551         dev->dev.parent = parent;
1552         dev->dev.groups = dev->groups;
1553         dev->dev.type = &iio_device_type;
1554         dev->dev.bus = &iio_bus_type;
1555         device_initialize(&dev->dev);
1556         dev_set_drvdata(&dev->dev, (void *)dev);
1557         mutex_init(&dev->mlock);
1558         mutex_init(&dev->info_exist_lock);
1559         INIT_LIST_HEAD(&iio_dev_opaque->channel_attr_list);
1560
1561         dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1562         if (dev->id < 0) {
1563                 /* cannot use a dev_err as the name isn't available */
1564                 pr_err("failed to get device id\n");
1565                 kfree(iio_dev_opaque);
1566                 return NULL;
1567         }
1568         dev_set_name(&dev->dev, "iio:device%d", dev->id);
1569         INIT_LIST_HEAD(&iio_dev_opaque->buffer_list);
1570
1571         return dev;
1572 }
1573 EXPORT_SYMBOL(iio_device_alloc);
1574
1575 /**
1576  * iio_device_free() - free an iio_dev from a driver
1577  * @dev:                the iio_dev associated with the device
1578  **/
1579 void iio_device_free(struct iio_dev *dev)
1580 {
1581         if (dev)
1582                 put_device(&dev->dev);
1583 }
1584 EXPORT_SYMBOL(iio_device_free);
1585
1586 static void devm_iio_device_release(struct device *dev, void *res)
1587 {
1588         iio_device_free(*(struct iio_dev **)res);
1589 }
1590
1591 /**
1592  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1593  * @parent:             Device to allocate iio_dev for, and parent for this IIO device
1594  * @sizeof_priv:        Space to allocate for private structure.
1595  *
1596  * Managed iio_device_alloc. iio_dev allocated with this function is
1597  * automatically freed on driver detach.
1598  *
1599  * RETURNS:
1600  * Pointer to allocated iio_dev on success, NULL on failure.
1601  */
1602 struct iio_dev *devm_iio_device_alloc(struct device *parent, int sizeof_priv)
1603 {
1604         struct iio_dev **ptr, *iio_dev;
1605
1606         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1607                            GFP_KERNEL);
1608         if (!ptr)
1609                 return NULL;
1610
1611         iio_dev = iio_device_alloc(parent, sizeof_priv);
1612         if (iio_dev) {
1613                 *ptr = iio_dev;
1614                 devres_add(parent, ptr);
1615         } else {
1616                 devres_free(ptr);
1617         }
1618
1619         return iio_dev;
1620 }
1621 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1622
1623 /**
1624  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1625  * @inode:      Inode structure for identifying the device in the file system
1626  * @filp:       File structure for iio device used to keep and later access
1627  *              private data
1628  *
1629  * Return: 0 on success or -EBUSY if the device is already opened
1630  **/
1631 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1632 {
1633         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1634                                                 struct iio_dev, chrdev);
1635
1636         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1637                 return -EBUSY;
1638
1639         iio_device_get(indio_dev);
1640
1641         filp->private_data = indio_dev;
1642
1643         return 0;
1644 }
1645
1646 /**
1647  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1648  * @inode:      Inode structure pointer for the char device
1649  * @filp:       File structure pointer for the char device
1650  *
1651  * Return: 0 for successful release
1652  */
1653 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1654 {
1655         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1656                                                 struct iio_dev, chrdev);
1657         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1658         iio_device_put(indio_dev);
1659
1660         return 0;
1661 }
1662
1663 /* Somewhat of a cross file organization violation - ioctls here are actually
1664  * event related */
1665 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1666 {
1667         struct iio_dev *indio_dev = filp->private_data;
1668         int __user *ip = (int __user *)arg;
1669         int fd;
1670
1671         if (!indio_dev->info)
1672                 return -ENODEV;
1673
1674         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1675                 fd = iio_event_getfd(indio_dev);
1676                 if (fd < 0)
1677                         return fd;
1678                 if (copy_to_user(ip, &fd, sizeof(fd)))
1679                         return -EFAULT;
1680                 return 0;
1681         }
1682         return -EINVAL;
1683 }
1684
1685 static const struct file_operations iio_buffer_fileops = {
1686         .read = iio_buffer_read_outer_addr,
1687         .release = iio_chrdev_release,
1688         .open = iio_chrdev_open,
1689         .poll = iio_buffer_poll_addr,
1690         .owner = THIS_MODULE,
1691         .llseek = noop_llseek,
1692         .unlocked_ioctl = iio_ioctl,
1693         .compat_ioctl = compat_ptr_ioctl,
1694 };
1695
1696 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1697 {
1698         int i, j;
1699         const struct iio_chan_spec *channels = indio_dev->channels;
1700
1701         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1702                 return 0;
1703
1704         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1705                 if (channels[i].scan_index < 0)
1706                         continue;
1707                 for (j = i + 1; j < indio_dev->num_channels; j++)
1708                         if (channels[i].scan_index == channels[j].scan_index) {
1709                                 dev_err(&indio_dev->dev,
1710                                         "Duplicate scan index %d\n",
1711                                         channels[i].scan_index);
1712                                 return -EINVAL;
1713                         }
1714         }
1715
1716         return 0;
1717 }
1718
1719 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1720
1721 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1722 {
1723         int ret;
1724
1725         if (!indio_dev->info)
1726                 return -EINVAL;
1727
1728         indio_dev->driver_module = this_mod;
1729         /* If the calling driver did not initialize of_node, do it here */
1730         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1731                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1732
1733         indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
1734                                            NULL);
1735
1736         ret = iio_check_unique_scan_index(indio_dev);
1737         if (ret < 0)
1738                 return ret;
1739
1740         /* configure elements for the chrdev */
1741         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1742
1743         iio_device_register_debugfs(indio_dev);
1744
1745         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1746         if (ret) {
1747                 dev_err(indio_dev->dev.parent,
1748                         "Failed to create buffer sysfs interfaces\n");
1749                 goto error_unreg_debugfs;
1750         }
1751
1752         ret = iio_device_register_sysfs(indio_dev);
1753         if (ret) {
1754                 dev_err(indio_dev->dev.parent,
1755                         "Failed to register sysfs interfaces\n");
1756                 goto error_buffer_free_sysfs;
1757         }
1758         ret = iio_device_register_eventset(indio_dev);
1759         if (ret) {
1760                 dev_err(indio_dev->dev.parent,
1761                         "Failed to register event set\n");
1762                 goto error_free_sysfs;
1763         }
1764         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1765                 iio_device_register_trigger_consumer(indio_dev);
1766
1767         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1768                 indio_dev->setup_ops == NULL)
1769                 indio_dev->setup_ops = &noop_ring_setup_ops;
1770
1771         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1772
1773         indio_dev->chrdev.owner = this_mod;
1774
1775         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1776         if (ret < 0)
1777                 goto error_unreg_eventset;
1778
1779         return 0;
1780
1781 error_unreg_eventset:
1782         iio_device_unregister_eventset(indio_dev);
1783 error_free_sysfs:
1784         iio_device_unregister_sysfs(indio_dev);
1785 error_buffer_free_sysfs:
1786         iio_buffer_free_sysfs_and_mask(indio_dev);
1787 error_unreg_debugfs:
1788         iio_device_unregister_debugfs(indio_dev);
1789         return ret;
1790 }
1791 EXPORT_SYMBOL(__iio_device_register);
1792
1793 /**
1794  * iio_device_unregister() - unregister a device from the IIO subsystem
1795  * @indio_dev:          Device structure representing the device.
1796  **/
1797 void iio_device_unregister(struct iio_dev *indio_dev)
1798 {
1799         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1800
1801         mutex_lock(&indio_dev->info_exist_lock);
1802
1803         iio_device_unregister_debugfs(indio_dev);
1804
1805         iio_disable_all_buffers(indio_dev);
1806
1807         indio_dev->info = NULL;
1808
1809         iio_device_wakeup_eventset(indio_dev);
1810         iio_buffer_wakeup_poll(indio_dev);
1811
1812         mutex_unlock(&indio_dev->info_exist_lock);
1813
1814         iio_buffer_free_sysfs_and_mask(indio_dev);
1815 }
1816 EXPORT_SYMBOL(iio_device_unregister);
1817
1818 static void devm_iio_device_unreg(struct device *dev, void *res)
1819 {
1820         iio_device_unregister(*(struct iio_dev **)res);
1821 }
1822
1823 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1824                                struct module *this_mod)
1825 {
1826         struct iio_dev **ptr;
1827         int ret;
1828
1829         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1830         if (!ptr)
1831                 return -ENOMEM;
1832
1833         *ptr = indio_dev;
1834         ret = __iio_device_register(indio_dev, this_mod);
1835         if (!ret)
1836                 devres_add(dev, ptr);
1837         else
1838                 devres_free(ptr);
1839
1840         return ret;
1841 }
1842 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1843
1844 /**
1845  * iio_device_claim_direct_mode - Keep device in direct mode
1846  * @indio_dev:  the iio_dev associated with the device
1847  *
1848  * If the device is in direct mode it is guaranteed to stay
1849  * that way until iio_device_release_direct_mode() is called.
1850  *
1851  * Use with iio_device_release_direct_mode()
1852  *
1853  * Returns: 0 on success, -EBUSY on failure
1854  */
1855 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1856 {
1857         mutex_lock(&indio_dev->mlock);
1858
1859         if (iio_buffer_enabled(indio_dev)) {
1860                 mutex_unlock(&indio_dev->mlock);
1861                 return -EBUSY;
1862         }
1863         return 0;
1864 }
1865 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1866
1867 /**
1868  * iio_device_release_direct_mode - releases claim on direct mode
1869  * @indio_dev:  the iio_dev associated with the device
1870  *
1871  * Release the claim. Device is no longer guaranteed to stay
1872  * in direct mode.
1873  *
1874  * Use with iio_device_claim_direct_mode()
1875  */
1876 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1877 {
1878         mutex_unlock(&indio_dev->mlock);
1879 }
1880 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1881
1882 subsys_initcall(iio_init);
1883 module_exit(iio_exit);
1884
1885 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1886 MODULE_DESCRIPTION("Industrial I/O core");
1887 MODULE_LICENSE("GPL");