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 "iio_core.h"
  29 #include "iio_core_trigger.h"
  30 #include <linux/iio/sysfs.h>
  31 #include <linux/iio/events.h>
  32 #include <linux/iio/buffer.h>
  33 #include <linux/iio/buffer_impl.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         [IIO_CONCENTRATION] = "concentration",
  79         [IIO_RESISTANCE] = "resistance",
  80         [IIO_PH] = "ph",
  81         [IIO_UVINDEX] = "uvindex",
  82         [IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  83         [IIO_COUNT] = "count",
  84         [IIO_INDEX] = "index",
  85         [IIO_GRAVITY]  = "gravity",
  86         [IIO_POSITIONRELATIVE]  = "positionrelative",
  87         [IIO_PHASE] = "phase",
  88         [IIO_MASSCONCENTRATION] = "massconcentration",
  89 };
  90
  91 static const char * const iio_modifier_names[] = {
  92         [IIO_MOD_X] = "x",
  93         [IIO_MOD_Y] = "y",
  94         [IIO_MOD_Z] = "z",
  95         [IIO_MOD_X_AND_Y] = "x&y",
  96         [IIO_MOD_X_AND_Z] = "x&z",
  97         [IIO_MOD_Y_AND_Z] = "y&z",
  98         [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
  99         [IIO_MOD_X_OR_Y] = "x|y",
 100         [IIO_MOD_X_OR_Z] = "x|z",
 101         [IIO_MOD_Y_OR_Z] = "y|z",
 102         [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 103         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 104         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 105         [IIO_MOD_LIGHT_BOTH] = "both",
 106         [IIO_MOD_LIGHT_IR] = "ir",
 107         [IIO_MOD_LIGHT_CLEAR] = "clear",
 108         [IIO_MOD_LIGHT_RED] = "red",
 109         [IIO_MOD_LIGHT_GREEN] = "green",
 110         [IIO_MOD_LIGHT_BLUE] = "blue",
 111         [IIO_MOD_LIGHT_UV] = "uv",
 112         [IIO_MOD_LIGHT_DUV] = "duv",
 113         [IIO_MOD_QUATERNION] = "quaternion",
 114         [IIO_MOD_TEMP_AMBIENT] = "ambient",
 115         [IIO_MOD_TEMP_OBJECT] = "object",
 116         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 117         [IIO_MOD_NORTH_TRUE] = "from_north_true",
 118         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 119         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 120         [IIO_MOD_RUNNING] = "running",
 121         [IIO_MOD_JOGGING] = "jogging",
 122         [IIO_MOD_WALKING] = "walking",
 123         [IIO_MOD_STILL] = "still",
 124         [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 125         [IIO_MOD_I] = "i",
 126         [IIO_MOD_Q] = "q",
 127         [IIO_MOD_CO2] = "co2",
 128         [IIO_MOD_VOC] = "voc",
 129         [IIO_MOD_PM1] = "pm1",
 130         [IIO_MOD_PM2P5] = "pm2p5",
 131         [IIO_MOD_PM4] = "pm4",
 132         [IIO_MOD_PM10] = "pm10",
 133 };
 134
 135 /* relies on pairs of these shared then separate */
 136 static const char * const iio_chan_info_postfix[] = {
 137         [IIO_CHAN_INFO_RAW] = "raw",
 138         [IIO_CHAN_INFO_PROCESSED] = "input",
 139         [IIO_CHAN_INFO_SCALE] = "scale",
 140         [IIO_CHAN_INFO_OFFSET] = "offset",
 141         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 142         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 143         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 144         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 145         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 146         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 147         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 148         = "filter_low_pass_3db_frequency",
 149         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 150         = "filter_high_pass_3db_frequency",
 151         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 152         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 153         [IIO_CHAN_INFO_PHASE] = "phase",
 154         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 155         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 156         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 157         [IIO_CHAN_INFO_ENABLE] = "en",
 158         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 159         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 160         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 161         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 162         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 163         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 164         [IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
 165 };
 166
 167 /**
 168  * iio_find_channel_from_si() - get channel from its scan index
 169  * @indio_dev:          device
 170  * @si:                 scan index to match
 171  */
 172 const struct iio_chan_spec
 173 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 174 {
 175         int i;
 176
 177         for (i = 0; i < indio_dev->num_channels; i++)
 178                 if (indio_dev->channels[i].scan_index == si)
 179                         return &indio_dev->channels[i];
 180         return NULL;
 181 }
 182
 183 /* This turns up an awful lot */
 184 ssize_t iio_read_const_attr(struct device *dev,
 185                             struct device_attribute *attr,
 186                             char *buf)
 187 {
 188         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 189 }
 190 EXPORT_SYMBOL(iio_read_const_attr);
 191
 192 /**
 193  * iio_device_set_clock() - Set current timestamping clock for the device
 194  * @indio_dev: IIO device structure containing the device
 195  * @clock_id: timestamping clock posix identifier to set.
 196  */
 197 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 198 {
 199         int ret;
 200         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 201
 202         ret = mutex_lock_interruptible(&indio_dev->mlock);
 203         if (ret)
 204                 return ret;
 205         if ((ev_int && iio_event_enabled(ev_int)) ||
 206             iio_buffer_enabled(indio_dev)) {
 207                 mutex_unlock(&indio_dev->mlock);
 208                 return -EBUSY;
 209         }
 210         indio_dev->clock_id = clock_id;
 211         mutex_unlock(&indio_dev->mlock);
 212
 213         return 0;
 214 }
 215 EXPORT_SYMBOL(iio_device_set_clock);
 216
 217 /**
 218  * iio_get_time_ns() - utility function to get a time stamp for events etc
 219  * @indio_dev: device
 220  */
 221 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 222 {
 223         struct timespec64 tp;
 224
 225         switch (iio_device_get_clock(indio_dev)) {
 226         case CLOCK_REALTIME:
 227                 return ktime_get_real_ns();
 228         case CLOCK_MONOTONIC:
 229                 return ktime_get_ns();
 230         case CLOCK_MONOTONIC_RAW:
 231                 return ktime_get_raw_ns();
 232         case CLOCK_REALTIME_COARSE:
 233                 return ktime_to_ns(ktime_get_coarse_real());
 234         case CLOCK_MONOTONIC_COARSE:
 235                 ktime_get_coarse_ts64(&tp);
 236                 return timespec64_to_ns(&tp);
 237         case CLOCK_BOOTTIME:
 238                 return ktime_get_boottime_ns();
 239         case CLOCK_TAI:
 240                 return ktime_get_clocktai_ns();
 241         default:
 242                 BUG();
 243         }
 244 }
 245 EXPORT_SYMBOL(iio_get_time_ns);
 246
 247 /**
 248  * iio_get_time_res() - utility function to get time stamp clock resolution in
 249  *                      nano seconds.
 250  * @indio_dev: device
 251  */
 252 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 253 {
 254         switch (iio_device_get_clock(indio_dev)) {
 255         case CLOCK_REALTIME:
 256         case CLOCK_MONOTONIC:
 257         case CLOCK_MONOTONIC_RAW:
 258         case CLOCK_BOOTTIME:
 259         case CLOCK_TAI:
 260                 return hrtimer_resolution;
 261         case CLOCK_REALTIME_COARSE:
 262         case CLOCK_MONOTONIC_COARSE:
 263                 return LOW_RES_NSEC;
 264         default:
 265                 BUG();
 266         }
 267 }
 268 EXPORT_SYMBOL(iio_get_time_res);
 269
 270 static int __init iio_init(void)
 271 {
 272         int ret;
 273
 274         /* Register sysfs bus */
 275         ret  = bus_register(&iio_bus_type);
 276         if (ret < 0) {
 277                 pr_err("could not register bus type\n");
 278                 goto error_nothing;
 279         }
 280
 281         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 282         if (ret < 0) {
 283                 pr_err("failed to allocate char dev region\n");
 284                 goto error_unregister_bus_type;
 285         }
 286
 287         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 288
 289         return 0;
 290
 291 error_unregister_bus_type:
 292         bus_unregister(&iio_bus_type);
 293 error_nothing:
 294         return ret;
 295 }
 296
 297 static void __exit iio_exit(void)
 298 {
 299         if (iio_devt)
 300                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 301         bus_unregister(&iio_bus_type);
 302         debugfs_remove(iio_debugfs_dentry);
 303 }
 304
 305 #if defined(CONFIG_DEBUG_FS)
 306 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 307                               size_t count, loff_t *ppos)
 308 {
 309         struct iio_dev *indio_dev = file->private_data;
 310         unsigned val = 0;
 311         int ret;
 312
 313         if (*ppos > 0)
 314                 return simple_read_from_buffer(userbuf, count, ppos,
 315                                                indio_dev->read_buf,
 316                                                indio_dev->read_buf_len);
 317
 318         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 319                                                   indio_dev->cached_reg_addr,
 320                                                   0, &val);
 321         if (ret) {
 322                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 323                 return ret;
 324         }
 325
 326         indio_dev->read_buf_len = snprintf(indio_dev->read_buf,
 327                                            sizeof(indio_dev->read_buf),
 328                                            "0x%X\n", val);
 329
 330         return simple_read_from_buffer(userbuf, count, ppos,
 331                                        indio_dev->read_buf,
 332                                        indio_dev->read_buf_len);
 333 }
 334
 335 static ssize_t iio_debugfs_write_reg(struct file *file,
 336                      const char __user *userbuf, size_t count, loff_t *ppos)
 337 {
 338         struct iio_dev *indio_dev = file->private_data;
 339         unsigned reg, val;
 340         char buf[80];
 341         int ret;
 342
 343         count = min_t(size_t, count, (sizeof(buf)-1));
 344         if (copy_from_user(buf, userbuf, count))
 345                 return -EFAULT;
 346
 347         buf[count] = 0;
 348
 349         ret = sscanf(buf, "%i %i", &reg, &val);
 350
 351         switch (ret) {
 352         case 1:
 353                 indio_dev->cached_reg_addr = reg;
 354                 break;
 355         case 2:
 356                 indio_dev->cached_reg_addr = reg;
 357                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 358                                                           val, NULL);
 359                 if (ret) {
 360                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 361                                 __func__);
 362                         return ret;
 363                 }
 364                 break;
 365         default:
 366                 return -EINVAL;
 367         }
 368
 369         return count;
 370 }
 371
 372 static const struct file_operations iio_debugfs_reg_fops = {
 373         .open = simple_open,
 374         .read = iio_debugfs_read_reg,
 375         .write = iio_debugfs_write_reg,
 376 };
 377
 378 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 379 {
 380         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 381 }
 382
 383 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 384 {
 385         if (indio_dev->info->debugfs_reg_access == NULL)
 386                 return;
 387
 388         if (!iio_debugfs_dentry)
 389                 return;
 390
 391         indio_dev->debugfs_dentry =
 392                 debugfs_create_dir(dev_name(&indio_dev->dev),
 393                                    iio_debugfs_dentry);
 394
 395         debugfs_create_file("direct_reg_access", 0644,
 396                             indio_dev->debugfs_dentry, indio_dev,
 397                             &iio_debugfs_reg_fops);
 398 }
 399 #else
 400 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 401 {
 402 }
 403
 404 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 405 {
 406 }
 407 #endif /* CONFIG_DEBUG_FS */
 408
 409 static ssize_t iio_read_channel_ext_info(struct device *dev,
 410                                      struct device_attribute *attr,
 411                                      char *buf)
 412 {
 413         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 414         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 415         const struct iio_chan_spec_ext_info *ext_info;
 416
 417         ext_info = &this_attr->c->ext_info[this_attr->address];
 418
 419         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 420 }
 421
 422 static ssize_t iio_write_channel_ext_info(struct device *dev,
 423                                      struct device_attribute *attr,
 424                                      const char *buf,
 425                                          size_t len)
 426 {
 427         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 428         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 429         const struct iio_chan_spec_ext_info *ext_info;
 430
 431         ext_info = &this_attr->c->ext_info[this_attr->address];
 432
 433         return ext_info->write(indio_dev, ext_info->private,
 434                                this_attr->c, buf, len);
 435 }
 436
 437 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 438         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 439 {
 440         const struct iio_enum *e = (const struct iio_enum *)priv;
 441         unsigned int i;
 442         size_t len = 0;
 443
 444         if (!e->num_items)
 445                 return 0;
 446
 447         for (i = 0; i < e->num_items; ++i)
 448                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 449
 450         /* replace last space with a newline */
 451         buf[len - 1] = '\n';
 452
 453         return len;
 454 }
 455 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 456
 457 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 458         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 459 {
 460         const struct iio_enum *e = (const struct iio_enum *)priv;
 461         int i;
 462
 463         if (!e->get)
 464                 return -EINVAL;
 465
 466         i = e->get(indio_dev, chan);
 467         if (i < 0)
 468                 return i;
 469         else if (i >= e->num_items)
 470                 return -EINVAL;
 471
 472         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 473 }
 474 EXPORT_SYMBOL_GPL(iio_enum_read);
 475
 476 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 477         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 478         size_t len)
 479 {
 480         const struct iio_enum *e = (const struct iio_enum *)priv;
 481         int ret;
 482
 483         if (!e->set)
 484                 return -EINVAL;
 485
 486         ret = __sysfs_match_string(e->items, e->num_items, buf);
 487         if (ret < 0)
 488                 return ret;
 489
 490         ret = e->set(indio_dev, chan, ret);
 491         return ret ? ret : len;
 492 }
 493 EXPORT_SYMBOL_GPL(iio_enum_write);
 494
 495 static const struct iio_mount_matrix iio_mount_idmatrix = {
 496         .rotation = {
 497                 "1", "0", "0",
 498                 "0", "1", "0",
 499                 "0", "0", "1"
 500         }
 501 };
 502
 503 static int iio_setup_mount_idmatrix(const struct device *dev,
 504                                     struct iio_mount_matrix *matrix)
 505 {
 506         *matrix = iio_mount_idmatrix;
 507         dev_info(dev, "mounting matrix not found: using identity...\n");
 508         return 0;
 509 }
 510
 511 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 512                               const struct iio_chan_spec *chan, char *buf)
 513 {
 514         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 515                                               priv)(indio_dev, chan);
 516
 517         if (IS_ERR(mtx))
 518                 return PTR_ERR(mtx);
 519
 520         if (!mtx)
 521                 mtx = &iio_mount_idmatrix;
 522
 523         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 524                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 525                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 526                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 527 }
 528 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 529
 530 /**
 531  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
 532  *                           device "mount-matrix" property
 533  * @dev:        device the mounting matrix property is assigned to
 534  * @propname:   device specific mounting matrix property name
 535  * @matrix:     where to store retrieved matrix
 536  *
 537  * If device is assigned no mounting matrix property, a default 3x3 identity
 538  * matrix will be filled in.
 539  *
 540  * Return: 0 if success, or a negative error code on failure.
 541  */
 542 int iio_read_mount_matrix(struct device *dev, const char *propname,
 543                           struct iio_mount_matrix *matrix)
 544 {
 545         size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
 546         int err;
 547
 548         err = device_property_read_string_array(dev, propname,
 549                                                 matrix->rotation, len);
 550         if (err == len)
 551                 return 0;
 552
 553         if (err >= 0)
 554                 /* Invalid number of matrix entries. */
 555                 return -EINVAL;
 556
 557         if (err != -EINVAL)
 558                 /* Invalid matrix declaration format. */
 559                 return err;
 560
 561         /* Matrix was not declared at all: fallback to identity. */
 562         return iio_setup_mount_idmatrix(dev, matrix);
 563 }
 564 EXPORT_SYMBOL(iio_read_mount_matrix);
 565
 566 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 567                                   int size, const int *vals)
 568 {
 569         unsigned long long tmp;
 570         int tmp0, tmp1;
 571         bool scale_db = false;
 572
 573         switch (type) {
 574         case IIO_VAL_INT:
 575                 return scnprintf(buf, len, "%d", vals[0]);
 576         case IIO_VAL_INT_PLUS_MICRO_DB:
 577                 scale_db = true;
 578                 /* fall through */
 579         case IIO_VAL_INT_PLUS_MICRO:
 580                 if (vals[1] < 0)
 581                         return scnprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 582                                         -vals[1], scale_db ? " dB" : "");
 583                 else
 584                         return scnprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 585                                         scale_db ? " dB" : "");
 586         case IIO_VAL_INT_PLUS_NANO:
 587                 if (vals[1] < 0)
 588                         return scnprintf(buf, len, "-%d.%09u", abs(vals[0]),
 589                                         -vals[1]);
 590                 else
 591                         return scnprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 592         case IIO_VAL_FRACTIONAL:
 593                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 594                 tmp1 = vals[1];
 595                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 596                 return scnprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 597         case IIO_VAL_FRACTIONAL_LOG2:
 598                 tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 599                 tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 600                 return scnprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 601         case IIO_VAL_INT_MULTIPLE:
 602         {
 603                 int i;
 604                 int l = 0;
 605
 606                 for (i = 0; i < size; ++i) {
 607                         l += scnprintf(&buf[l], len - l, "%d ", vals[i]);
 608                         if (l >= len)
 609                                 break;
 610                 }
 611                 return l;
 612         }
 613         case IIO_VAL_CHAR:
 614                 return scnprintf(buf, len, "%c", (char)vals[0]);
 615         default:
 616                 return 0;
 617         }
 618 }
 619
 620 /**
 621  * iio_format_value() - Formats a IIO value into its string representation
 622  * @buf:        The buffer to which the formatted value gets written
 623  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 624  * @type:       One of the IIO_VAL_* constants. This decides how the val
 625  *              and val2 parameters are formatted.
 626  * @size:       Number of IIO value entries contained in vals
 627  * @vals:       Pointer to the values, exact meaning depends on the
 628  *              type parameter.
 629  *
 630  * Return: 0 by default, a negative number on failure or the
 631  *         total number of characters written for a type that belongs
 632  *         to the IIO_VAL_* constant.
 633  */
 634 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 635 {
 636         ssize_t len;
 637
 638         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 639         if (len >= PAGE_SIZE - 1)
 640                 return -EFBIG;
 641
 642         return len + sprintf(buf + len, "\n");
 643 }
 644 EXPORT_SYMBOL_GPL(iio_format_value);
 645
 646 static ssize_t iio_read_channel_info(struct device *dev,
 647                                      struct device_attribute *attr,
 648                                      char *buf)
 649 {
 650         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 651         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 652         int vals[INDIO_MAX_RAW_ELEMENTS];
 653         int ret;
 654         int val_len = 2;
 655
 656         if (indio_dev->info->read_raw_multi)
 657                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 658                                                         INDIO_MAX_RAW_ELEMENTS,
 659                                                         vals, &val_len,
 660                                                         this_attr->address);
 661         else
 662                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 663                                     &vals[0], &vals[1], this_attr->address);
 664
 665         if (ret < 0)
 666                 return ret;
 667
 668         return iio_format_value(buf, ret, val_len, vals);
 669 }
 670
 671 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 672                                      int type, int length)
 673 {
 674         int i;
 675         ssize_t len = 0;
 676
 677         switch (type) {
 678         case IIO_VAL_INT:
 679                 for (i = 0; i < length; i++) {
 680                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 681                                                   type, 1, &vals[i]);
 682                         if (len >= PAGE_SIZE)
 683                                 return -EFBIG;
 684                         if (i < length - 1)
 685                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 686                                                 " ");
 687                         else
 688                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 689                                                 "\n");
 690                         if (len >= PAGE_SIZE)
 691                                 return -EFBIG;
 692                 }
 693                 break;
 694         default:
 695                 for (i = 0; i < length / 2; i++) {
 696                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 697                                                   type, 2, &vals[i * 2]);
 698                         if (len >= PAGE_SIZE)
 699                                 return -EFBIG;
 700                         if (i < length / 2 - 1)
 701                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 702                                                 " ");
 703                         else
 704                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 705                                                 "\n");
 706                         if (len >= PAGE_SIZE)
 707                                 return -EFBIG;
 708                 }
 709         }
 710
 711         return len;
 712 }
 713
 714 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 715 {
 716         int i;
 717         ssize_t len;
 718
 719         len = snprintf(buf, PAGE_SIZE, "[");
 720         switch (type) {
 721         case IIO_VAL_INT:
 722                 for (i = 0; i < 3; i++) {
 723                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 724                                                   type, 1, &vals[i]);
 725                         if (len >= PAGE_SIZE)
 726                                 return -EFBIG;
 727                         if (i < 2)
 728                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 729                                                 " ");
 730                         else
 731                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 732                                                 "]\n");
 733                         if (len >= PAGE_SIZE)
 734                                 return -EFBIG;
 735                 }
 736                 break;
 737         default:
 738                 for (i = 0; i < 3; i++) {
 739                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 740                                                   type, 2, &vals[i * 2]);
 741                         if (len >= PAGE_SIZE)
 742                                 return -EFBIG;
 743                         if (i < 2)
 744                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 745                                                 " ");
 746                         else
 747                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 748                                                 "]\n");
 749                         if (len >= PAGE_SIZE)
 750                                 return -EFBIG;
 751                 }
 752         }
 753
 754         return len;
 755 }
 756
 757 static ssize_t iio_read_channel_info_avail(struct device *dev,
 758                                            struct device_attribute *attr,
 759                                            char *buf)
 760 {
 761         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 762         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 763         const int *vals;
 764         int ret;
 765         int length;
 766         int type;
 767
 768         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 769                                           &vals, &type, &length,
 770                                           this_attr->address);
 771
 772         if (ret < 0)
 773                 return ret;
 774         switch (ret) {
 775         case IIO_AVAIL_LIST:
 776                 return iio_format_avail_list(buf, vals, type, length);
 777         case IIO_AVAIL_RANGE:
 778                 return iio_format_avail_range(buf, vals, type);
 779         default:
 780                 return -EINVAL;
 781         }
 782 }
 783
 784 /**
 785  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
 786  * @str: The string to parse
 787  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 788  * @integer: The integer part of the number
 789  * @fract: The fractional part of the number
 790  * @scale_db: True if this should parse as dB
 791  *
 792  * Returns 0 on success, or a negative error code if the string could not be
 793  * parsed.
 794  */
 795 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
 796                                  int *integer, int *fract, bool scale_db)
 797 {
 798         int i = 0, f = 0;
 799         bool integer_part = true, negative = false;
 800
 801         if (fract_mult == 0) {
 802                 *fract = 0;
 803
 804                 return kstrtoint(str, 0, integer);
 805         }
 806
 807         if (str[0] == '-') {
 808                 negative = true;
 809                 str++;
 810         } else if (str[0] == '+') {
 811                 str++;
 812         }
 813
 814         while (*str) {
 815                 if ('0' <= *str && *str <= '9') {
 816                         if (integer_part) {
 817                                 i = i * 10 + *str - '0';
 818                         } else {
 819                                 f += fract_mult * (*str - '0');
 820                                 fract_mult /= 10;
 821                         }
 822                 } else if (*str == '\n') {
 823                         if (*(str + 1) == '\0')
 824                                 break;
 825                         else
 826                                 return -EINVAL;
 827                 } else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
 828                         /* Ignore the dB suffix */
 829                         str += sizeof(" dB") - 1;
 830                         continue;
 831                 } else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
 832                         /* Ignore the dB suffix */
 833                         str += sizeof("dB") - 1;
 834                         continue;
 835                 } else if (*str == '.' && integer_part) {
 836                         integer_part = false;
 837                 } else {
 838                         return -EINVAL;
 839                 }
 840                 str++;
 841         }
 842
 843         if (negative) {
 844                 if (i)
 845                         i = -i;
 846                 else
 847                         f = -f;
 848         }
 849
 850         *integer = i;
 851         *fract = f;
 852
 853         return 0;
 854 }
 855
 856 /**
 857  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 858  * @str: The string to parse
 859  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 860  * @integer: The integer part of the number
 861  * @fract: The fractional part of the number
 862  *
 863  * Returns 0 on success, or a negative error code if the string could not be
 864  * parsed.
 865  */
 866 int iio_str_to_fixpoint(const char *str, int fract_mult,
 867                         int *integer, int *fract)
 868 {
 869         return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
 870 }
 871 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 872
 873 static ssize_t iio_write_channel_info(struct device *dev,
 874                                       struct device_attribute *attr,
 875                                       const char *buf,
 876                                       size_t len)
 877 {
 878         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 879         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 880         int ret, fract_mult = 100000;
 881         int integer, fract = 0;
 882         bool is_char = false;
 883         bool scale_db = false;
 884
 885         /* Assumes decimal - precision based on number of digits */
 886         if (!indio_dev->info->write_raw)
 887                 return -EINVAL;
 888
 889         if (indio_dev->info->write_raw_get_fmt)
 890                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 891                         this_attr->c, this_attr->address)) {
 892                 case IIO_VAL_INT:
 893                         fract_mult = 0;
 894                         break;
 895                 case IIO_VAL_INT_PLUS_MICRO_DB:
 896                         scale_db = true;
 897                         /* fall through */
 898                 case IIO_VAL_INT_PLUS_MICRO:
 899                         fract_mult = 100000;
 900                         break;
 901                 case IIO_VAL_INT_PLUS_NANO:
 902                         fract_mult = 100000000;
 903                         break;
 904                 case IIO_VAL_CHAR:
 905                         is_char = true;
 906                         break;
 907                 default:
 908                         return -EINVAL;
 909                 }
 910
 911         if (is_char) {
 912                 char ch;
 913
 914                 if (sscanf(buf, "%c", &ch) != 1)
 915                         return -EINVAL;
 916                 integer = ch;
 917         } else {
 918                 ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
 919                                             scale_db);
 920                 if (ret)
 921                         return ret;
 922         }
 923
 924         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 925                                          integer, fract, this_attr->address);
 926         if (ret)
 927                 return ret;
 928
 929         return len;
 930 }
 931
 932 static
 933 int __iio_device_attr_init(struct device_attribute *dev_attr,
 934                            const char *postfix,
 935                            struct iio_chan_spec const *chan,
 936                            ssize_t (*readfunc)(struct device *dev,
 937                                                struct device_attribute *attr,
 938                                                char *buf),
 939                            ssize_t (*writefunc)(struct device *dev,
 940                                                 struct device_attribute *attr,
 941                                                 const char *buf,
 942                                                 size_t len),
 943                            enum iio_shared_by shared_by)
 944 {
 945         int ret = 0;
 946         char *name = NULL;
 947         char *full_postfix;
 948         sysfs_attr_init(&dev_attr->attr);
 949
 950         /* Build up postfix of <extend_name>_<modifier>_postfix */
 951         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 952                 if (chan->extend_name)
 953                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 954                                                  iio_modifier_names[chan
 955                                                                     ->channel2],
 956                                                  chan->extend_name,
 957                                                  postfix);
 958                 else
 959                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 960                                                  iio_modifier_names[chan
 961                                                                     ->channel2],
 962                                                  postfix);
 963         } else {
 964                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 965                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 966                 else
 967                         full_postfix = kasprintf(GFP_KERNEL,
 968                                                  "%s_%s",
 969                                                  chan->extend_name,
 970                                                  postfix);
 971         }
 972         if (full_postfix == NULL)
 973                 return -ENOMEM;
 974
 975         if (chan->differential) { /* Differential can not have modifier */
 976                 switch (shared_by) {
 977                 case IIO_SHARED_BY_ALL:
 978                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 979                         break;
 980                 case IIO_SHARED_BY_DIR:
 981                         name = kasprintf(GFP_KERNEL, "%s_%s",
 982                                                 iio_direction[chan->output],
 983                                                 full_postfix);
 984                         break;
 985                 case IIO_SHARED_BY_TYPE:
 986                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 987                                             iio_direction[chan->output],
 988                                             iio_chan_type_name_spec[chan->type],
 989                                             iio_chan_type_name_spec[chan->type],
 990                                             full_postfix);
 991                         break;
 992                 case IIO_SEPARATE:
 993                         if (!chan->indexed) {
 994                                 WARN(1, "Differential channels must be indexed\n");
 995                                 ret = -EINVAL;
 996                                 goto error_free_full_postfix;
 997                         }
 998                         name = kasprintf(GFP_KERNEL,
 999                                             "%s_%s%d-%s%d_%s",
1000                                             iio_direction[chan->output],
1001                                             iio_chan_type_name_spec[chan->type],
1002                                             chan->channel,
1003                                             iio_chan_type_name_spec[chan->type],
1004                                             chan->channel2,
1005                                             full_postfix);
1006                         break;
1007                 }
1008         } else { /* Single ended */
1009                 switch (shared_by) {
1010                 case IIO_SHARED_BY_ALL:
1011                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1012                         break;
1013                 case IIO_SHARED_BY_DIR:
1014                         name = kasprintf(GFP_KERNEL, "%s_%s",
1015                                                 iio_direction[chan->output],
1016                                                 full_postfix);
1017                         break;
1018                 case IIO_SHARED_BY_TYPE:
1019                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1020                                             iio_direction[chan->output],
1021                                             iio_chan_type_name_spec[chan->type],
1022                                             full_postfix);
1023                         break;
1024
1025                 case IIO_SEPARATE:
1026                         if (chan->indexed)
1027                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1028                                                     iio_direction[chan->output],
1029                                                     iio_chan_type_name_spec[chan->type],
1030                                                     chan->channel,
1031                                                     full_postfix);
1032                         else
1033                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1034                                                     iio_direction[chan->output],
1035                                                     iio_chan_type_name_spec[chan->type],
1036                                                     full_postfix);
1037                         break;
1038                 }
1039         }
1040         if (name == NULL) {
1041                 ret = -ENOMEM;
1042                 goto error_free_full_postfix;
1043         }
1044         dev_attr->attr.name = name;
1045
1046         if (readfunc) {
1047                 dev_attr->attr.mode |= S_IRUGO;
1048                 dev_attr->show = readfunc;
1049         }
1050
1051         if (writefunc) {
1052                 dev_attr->attr.mode |= S_IWUSR;
1053                 dev_attr->store = writefunc;
1054         }
1055
1056 error_free_full_postfix:
1057         kfree(full_postfix);
1058
1059         return ret;
1060 }
1061
1062 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1063 {
1064         kfree(dev_attr->attr.name);
1065 }
1066
1067 int __iio_add_chan_devattr(const char *postfix,
1068                            struct iio_chan_spec const *chan,
1069                            ssize_t (*readfunc)(struct device *dev,
1070                                                struct device_attribute *attr,
1071                                                char *buf),
1072                            ssize_t (*writefunc)(struct device *dev,
1073                                                 struct device_attribute *attr,
1074                                                 const char *buf,
1075                                                 size_t len),
1076                            u64 mask,
1077                            enum iio_shared_by shared_by,
1078                            struct device *dev,
1079                            struct list_head *attr_list)
1080 {
1081         int ret;
1082         struct iio_dev_attr *iio_attr, *t;
1083
1084         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1085         if (iio_attr == NULL)
1086                 return -ENOMEM;
1087         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1088                                      postfix, chan,
1089                                      readfunc, writefunc, shared_by);
1090         if (ret)
1091                 goto error_iio_dev_attr_free;
1092         iio_attr->c = chan;
1093         iio_attr->address = mask;
1094         list_for_each_entry(t, attr_list, l)
1095                 if (strcmp(t->dev_attr.attr.name,
1096                            iio_attr->dev_attr.attr.name) == 0) {
1097                         if (shared_by == IIO_SEPARATE)
1098                                 dev_err(dev, "tried to double register : %s\n",
1099                                         t->dev_attr.attr.name);
1100                         ret = -EBUSY;
1101                         goto error_device_attr_deinit;
1102                 }
1103         list_add(&iio_attr->l, attr_list);
1104
1105         return 0;
1106
1107 error_device_attr_deinit:
1108         __iio_device_attr_deinit(&iio_attr->dev_attr);
1109 error_iio_dev_attr_free:
1110         kfree(iio_attr);
1111         return ret;
1112 }
1113
1114 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1115                                          struct iio_chan_spec const *chan,
1116                                          enum iio_shared_by shared_by,
1117                                          const long *infomask)
1118 {
1119         int i, ret, attrcount = 0;
1120
1121         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1122                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1123                         return -EINVAL;
1124                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1125                                              chan,
1126                                              &iio_read_channel_info,
1127                                              &iio_write_channel_info,
1128                                              i,
1129                                              shared_by,
1130                                              &indio_dev->dev,
1131                                              &indio_dev->channel_attr_list);
1132                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1133                         continue;
1134                 else if (ret < 0)
1135                         return ret;
1136                 attrcount++;
1137         }
1138
1139         return attrcount;
1140 }
1141
1142 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1143                                                struct iio_chan_spec const *chan,
1144                                                enum iio_shared_by shared_by,
1145                                                const long *infomask)
1146 {
1147         int i, ret, attrcount = 0;
1148         char *avail_postfix;
1149
1150         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1151                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1152                         return -EINVAL;
1153                 avail_postfix = kasprintf(GFP_KERNEL,
1154                                           "%s_available",
1155                                           iio_chan_info_postfix[i]);
1156                 if (!avail_postfix)
1157                         return -ENOMEM;
1158
1159                 ret = __iio_add_chan_devattr(avail_postfix,
1160                                              chan,
1161                                              &iio_read_channel_info_avail,
1162                                              NULL,
1163                                              i,
1164                                              shared_by,
1165                                              &indio_dev->dev,
1166                                              &indio_dev->channel_attr_list);
1167                 kfree(avail_postfix);
1168                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1169                         continue;
1170                 else if (ret < 0)
1171                         return ret;
1172                 attrcount++;
1173         }
1174
1175         return attrcount;
1176 }
1177
1178 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1179                                         struct iio_chan_spec const *chan)
1180 {
1181         int ret, attrcount = 0;
1182         const struct iio_chan_spec_ext_info *ext_info;
1183
1184         if (chan->channel < 0)
1185                 return 0;
1186         ret = iio_device_add_info_mask_type(indio_dev, chan,
1187                                             IIO_SEPARATE,
1188                                             &chan->info_mask_separate);
1189         if (ret < 0)
1190                 return ret;
1191         attrcount += ret;
1192
1193         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1194                                                   IIO_SEPARATE,
1195                                                   &chan->
1196                                                   info_mask_separate_available);
1197         if (ret < 0)
1198                 return ret;
1199         attrcount += ret;
1200
1201         ret = iio_device_add_info_mask_type(indio_dev, chan,
1202                                             IIO_SHARED_BY_TYPE,
1203                                             &chan->info_mask_shared_by_type);
1204         if (ret < 0)
1205                 return ret;
1206         attrcount += ret;
1207
1208         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1209                                                   IIO_SHARED_BY_TYPE,
1210                                                   &chan->
1211                                                   info_mask_shared_by_type_available);
1212         if (ret < 0)
1213                 return ret;
1214         attrcount += ret;
1215
1216         ret = iio_device_add_info_mask_type(indio_dev, chan,
1217                                             IIO_SHARED_BY_DIR,
1218                                             &chan->info_mask_shared_by_dir);
1219         if (ret < 0)
1220                 return ret;
1221         attrcount += ret;
1222
1223         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1224                                                   IIO_SHARED_BY_DIR,
1225                                                   &chan->info_mask_shared_by_dir_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_ALL,
1232                                             &chan->info_mask_shared_by_all);
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_ALL,
1239                                                   &chan->info_mask_shared_by_all_available);
1240         if (ret < 0)
1241                 return ret;
1242         attrcount += ret;
1243
1244         if (chan->ext_info) {
1245                 unsigned int i = 0;
1246                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1247                         ret = __iio_add_chan_devattr(ext_info->name,
1248                                         chan,
1249                                         ext_info->read ?
1250                                             &iio_read_channel_ext_info : NULL,
1251                                         ext_info->write ?
1252                                             &iio_write_channel_ext_info : NULL,
1253                                         i,
1254                                         ext_info->shared,
1255                                         &indio_dev->dev,
1256                                         &indio_dev->channel_attr_list);
1257                         i++;
1258                         if (ret == -EBUSY && ext_info->shared)
1259                                 continue;
1260
1261                         if (ret)
1262                                 return ret;
1263
1264                         attrcount++;
1265                 }
1266         }
1267
1268         return attrcount;
1269 }
1270
1271 /**
1272  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1273  * @attr_list: List of IIO device attributes
1274  *
1275  * This function frees the memory allocated for each of the IIO device
1276  * attributes in the list.
1277  */
1278 void iio_free_chan_devattr_list(struct list_head *attr_list)
1279 {
1280         struct iio_dev_attr *p, *n;
1281
1282         list_for_each_entry_safe(p, n, attr_list, l) {
1283                 kfree(p->dev_attr.attr.name);
1284                 list_del(&p->l);
1285                 kfree(p);
1286         }
1287 }
1288
1289 static ssize_t iio_show_dev_name(struct device *dev,
1290                                  struct device_attribute *attr,
1291                                  char *buf)
1292 {
1293         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1294         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1295 }
1296
1297 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1298
1299 static ssize_t iio_show_dev_label(struct device *dev,
1300                                  struct device_attribute *attr,
1301                                  char *buf)
1302 {
1303         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1304         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
1305 }
1306
1307 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1308
1309 static ssize_t iio_show_timestamp_clock(struct device *dev,
1310                                         struct device_attribute *attr,
1311                                         char *buf)
1312 {
1313         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1314         const clockid_t clk = iio_device_get_clock(indio_dev);
1315         const char *name;
1316         ssize_t sz;
1317
1318         switch (clk) {
1319         case CLOCK_REALTIME:
1320                 name = "realtime\n";
1321                 sz = sizeof("realtime\n");
1322                 break;
1323         case CLOCK_MONOTONIC:
1324                 name = "monotonic\n";
1325                 sz = sizeof("monotonic\n");
1326                 break;
1327         case CLOCK_MONOTONIC_RAW:
1328                 name = "monotonic_raw\n";
1329                 sz = sizeof("monotonic_raw\n");
1330                 break;
1331         case CLOCK_REALTIME_COARSE:
1332                 name = "realtime_coarse\n";
1333                 sz = sizeof("realtime_coarse\n");
1334                 break;
1335         case CLOCK_MONOTONIC_COARSE:
1336                 name = "monotonic_coarse\n";
1337                 sz = sizeof("monotonic_coarse\n");
1338                 break;
1339         case CLOCK_BOOTTIME:
1340                 name = "boottime\n";
1341                 sz = sizeof("boottime\n");
1342                 break;
1343         case CLOCK_TAI:
1344                 name = "tai\n";
1345                 sz = sizeof("tai\n");
1346                 break;
1347         default:
1348                 BUG();
1349         }
1350
1351         memcpy(buf, name, sz);
1352         return sz;
1353 }
1354
1355 static ssize_t iio_store_timestamp_clock(struct device *dev,
1356                                          struct device_attribute *attr,
1357                                          const char *buf, size_t len)
1358 {
1359         clockid_t clk;
1360         int ret;
1361
1362         if (sysfs_streq(buf, "realtime"))
1363                 clk = CLOCK_REALTIME;
1364         else if (sysfs_streq(buf, "monotonic"))
1365                 clk = CLOCK_MONOTONIC;
1366         else if (sysfs_streq(buf, "monotonic_raw"))
1367                 clk = CLOCK_MONOTONIC_RAW;
1368         else if (sysfs_streq(buf, "realtime_coarse"))
1369                 clk = CLOCK_REALTIME_COARSE;
1370         else if (sysfs_streq(buf, "monotonic_coarse"))
1371                 clk = CLOCK_MONOTONIC_COARSE;
1372         else if (sysfs_streq(buf, "boottime"))
1373                 clk = CLOCK_BOOTTIME;
1374         else if (sysfs_streq(buf, "tai"))
1375                 clk = CLOCK_TAI;
1376         else
1377                 return -EINVAL;
1378
1379         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1380         if (ret)
1381                 return ret;
1382
1383         return len;
1384 }
1385
1386 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1387                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1388
1389 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1390 {
1391         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1392         struct iio_dev_attr *p;
1393         struct attribute **attr, *clk = NULL;
1394
1395         /* First count elements in any existing group */
1396         if (indio_dev->info->attrs) {
1397                 attr = indio_dev->info->attrs->attrs;
1398                 while (*attr++ != NULL)
1399                         attrcount_orig++;
1400         }
1401         attrcount = attrcount_orig;
1402         /*
1403          * New channel registration method - relies on the fact a group does
1404          * not need to be initialized if its name is NULL.
1405          */
1406         if (indio_dev->channels)
1407                 for (i = 0; i < indio_dev->num_channels; i++) {
1408                         const struct iio_chan_spec *chan =
1409                                 &indio_dev->channels[i];
1410
1411                         if (chan->type == IIO_TIMESTAMP)
1412                                 clk = &dev_attr_current_timestamp_clock.attr;
1413
1414                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1415                         if (ret < 0)
1416                                 goto error_clear_attrs;
1417                         attrcount += ret;
1418                 }
1419
1420         if (indio_dev->event_interface)
1421                 clk = &dev_attr_current_timestamp_clock.attr;
1422
1423         if (indio_dev->name)
1424                 attrcount++;
1425         if (indio_dev->label)
1426                 attrcount++;
1427         if (clk)
1428                 attrcount++;
1429
1430         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1431                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1432                                                    GFP_KERNEL);
1433         if (indio_dev->chan_attr_group.attrs == NULL) {
1434                 ret = -ENOMEM;
1435                 goto error_clear_attrs;
1436         }
1437         /* Copy across original attributes */
1438         if (indio_dev->info->attrs)
1439                 memcpy(indio_dev->chan_attr_group.attrs,
1440                        indio_dev->info->attrs->attrs,
1441                        sizeof(indio_dev->chan_attr_group.attrs[0])
1442                        *attrcount_orig);
1443         attrn = attrcount_orig;
1444         /* Add all elements from the list. */
1445         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1446                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1447         if (indio_dev->name)
1448                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1449         if (indio_dev->label)
1450                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1451         if (clk)
1452                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1453
1454         indio_dev->groups[indio_dev->groupcounter++] =
1455                 &indio_dev->chan_attr_group;
1456
1457         return 0;
1458
1459 error_clear_attrs:
1460         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1461
1462         return ret;
1463 }
1464
1465 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1466 {
1467
1468         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1469         kfree(indio_dev->chan_attr_group.attrs);
1470         indio_dev->chan_attr_group.attrs = NULL;
1471 }
1472
1473 static void iio_dev_release(struct device *device)
1474 {
1475         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1476         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1477                 iio_device_unregister_trigger_consumer(indio_dev);
1478         iio_device_unregister_eventset(indio_dev);
1479         iio_device_unregister_sysfs(indio_dev);
1480
1481         iio_buffer_put(indio_dev->buffer);
1482
1483         ida_simple_remove(&iio_ida, indio_dev->id);
1484         kfree(indio_dev);
1485 }
1486
1487 struct device_type iio_device_type = {
1488         .name = "iio_device",
1489         .release = iio_dev_release,
1490 };
1491
1492 /**
1493  * iio_device_alloc() - allocate an iio_dev from a driver
1494  * @sizeof_priv:        Space to allocate for private structure.
1495  **/
1496 struct iio_dev *iio_device_alloc(int sizeof_priv)
1497 {
1498         struct iio_dev *dev;
1499         size_t alloc_size;
1500
1501         alloc_size = sizeof(struct iio_dev);
1502         if (sizeof_priv) {
1503                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1504                 alloc_size += sizeof_priv;
1505         }
1506         /* ensure 32-byte alignment of whole construct ? */
1507         alloc_size += IIO_ALIGN - 1;
1508
1509         dev = kzalloc(alloc_size, GFP_KERNEL);
1510         if (!dev)
1511                 return NULL;
1512
1513         dev->dev.groups = dev->groups;
1514         dev->dev.type = &iio_device_type;
1515         dev->dev.bus = &iio_bus_type;
1516         device_initialize(&dev->dev);
1517         dev_set_drvdata(&dev->dev, (void *)dev);
1518         mutex_init(&dev->mlock);
1519         mutex_init(&dev->info_exist_lock);
1520         INIT_LIST_HEAD(&dev->channel_attr_list);
1521
1522         dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1523         if (dev->id < 0) {
1524                 /* cannot use a dev_err as the name isn't available */
1525                 pr_err("failed to get device id\n");
1526                 kfree(dev);
1527                 return NULL;
1528         }
1529         dev_set_name(&dev->dev, "iio:device%d", dev->id);
1530         INIT_LIST_HEAD(&dev->buffer_list);
1531
1532         return dev;
1533 }
1534 EXPORT_SYMBOL(iio_device_alloc);
1535
1536 /**
1537  * iio_device_free() - free an iio_dev from a driver
1538  * @dev:                the iio_dev associated with the device
1539  **/
1540 void iio_device_free(struct iio_dev *dev)
1541 {
1542         if (dev)
1543                 put_device(&dev->dev);
1544 }
1545 EXPORT_SYMBOL(iio_device_free);
1546
1547 static void devm_iio_device_release(struct device *dev, void *res)
1548 {
1549         iio_device_free(*(struct iio_dev **)res);
1550 }
1551
1552 /**
1553  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1554  * @dev:                Device to allocate iio_dev for
1555  * @sizeof_priv:        Space to allocate for private structure.
1556  *
1557  * Managed iio_device_alloc. iio_dev allocated with this function is
1558  * automatically freed on driver detach.
1559  *
1560  * RETURNS:
1561  * Pointer to allocated iio_dev on success, NULL on failure.
1562  */
1563 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1564 {
1565         struct iio_dev **ptr, *iio_dev;
1566
1567         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1568                            GFP_KERNEL);
1569         if (!ptr)
1570                 return NULL;
1571
1572         iio_dev = iio_device_alloc(sizeof_priv);
1573         if (iio_dev) {
1574                 *ptr = iio_dev;
1575                 devres_add(dev, ptr);
1576         } else {
1577                 devres_free(ptr);
1578         }
1579
1580         return iio_dev;
1581 }
1582 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1583
1584 /**
1585  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1586  * @inode:      Inode structure for identifying the device in the file system
1587  * @filp:       File structure for iio device used to keep and later access
1588  *              private data
1589  *
1590  * Return: 0 on success or -EBUSY if the device is already opened
1591  **/
1592 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1593 {
1594         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1595                                                 struct iio_dev, chrdev);
1596
1597         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1598                 return -EBUSY;
1599
1600         iio_device_get(indio_dev);
1601
1602         filp->private_data = indio_dev;
1603
1604         return 0;
1605 }
1606
1607 /**
1608  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1609  * @inode:      Inode structure pointer for the char device
1610  * @filp:       File structure pointer for the char device
1611  *
1612  * Return: 0 for successful release
1613  */
1614 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1615 {
1616         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1617                                                 struct iio_dev, chrdev);
1618         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1619         iio_device_put(indio_dev);
1620
1621         return 0;
1622 }
1623
1624 /* Somewhat of a cross file organization violation - ioctls here are actually
1625  * event related */
1626 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1627 {
1628         struct iio_dev *indio_dev = filp->private_data;
1629         int __user *ip = (int __user *)arg;
1630         int fd;
1631
1632         if (!indio_dev->info)
1633                 return -ENODEV;
1634
1635         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1636                 fd = iio_event_getfd(indio_dev);
1637                 if (fd < 0)
1638                         return fd;
1639                 if (copy_to_user(ip, &fd, sizeof(fd)))
1640                         return -EFAULT;
1641                 return 0;
1642         }
1643         return -EINVAL;
1644 }
1645
1646 static const struct file_operations iio_buffer_fileops = {
1647         .read = iio_buffer_read_outer_addr,
1648         .release = iio_chrdev_release,
1649         .open = iio_chrdev_open,
1650         .poll = iio_buffer_poll_addr,
1651         .owner = THIS_MODULE,
1652         .llseek = noop_llseek,
1653         .unlocked_ioctl = iio_ioctl,
1654         .compat_ioctl = compat_ptr_ioctl,
1655 };
1656
1657 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1658 {
1659         int i, j;
1660         const struct iio_chan_spec *channels = indio_dev->channels;
1661
1662         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1663                 return 0;
1664
1665         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1666                 if (channels[i].scan_index < 0)
1667                         continue;
1668                 for (j = i + 1; j < indio_dev->num_channels; j++)
1669                         if (channels[i].scan_index == channels[j].scan_index) {
1670                                 dev_err(&indio_dev->dev,
1671                                         "Duplicate scan index %d\n",
1672                                         channels[i].scan_index);
1673                                 return -EINVAL;
1674                         }
1675         }
1676
1677         return 0;
1678 }
1679
1680 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1681
1682 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1683 {
1684         int ret;
1685
1686         if (!indio_dev->info)
1687                 return -EINVAL;
1688
1689         indio_dev->driver_module = this_mod;
1690         /* If the calling driver did not initialize of_node, do it here */
1691         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1692                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1693
1694         indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
1695                                            NULL);
1696
1697         ret = iio_check_unique_scan_index(indio_dev);
1698         if (ret < 0)
1699                 return ret;
1700
1701         /* configure elements for the chrdev */
1702         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1703
1704         iio_device_register_debugfs(indio_dev);
1705
1706         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1707         if (ret) {
1708                 dev_err(indio_dev->dev.parent,
1709                         "Failed to create buffer sysfs interfaces\n");
1710                 goto error_unreg_debugfs;
1711         }
1712
1713         ret = iio_device_register_sysfs(indio_dev);
1714         if (ret) {
1715                 dev_err(indio_dev->dev.parent,
1716                         "Failed to register sysfs interfaces\n");
1717                 goto error_buffer_free_sysfs;
1718         }
1719         ret = iio_device_register_eventset(indio_dev);
1720         if (ret) {
1721                 dev_err(indio_dev->dev.parent,
1722                         "Failed to register event set\n");
1723                 goto error_free_sysfs;
1724         }
1725         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1726                 iio_device_register_trigger_consumer(indio_dev);
1727
1728         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1729                 indio_dev->setup_ops == NULL)
1730                 indio_dev->setup_ops = &noop_ring_setup_ops;
1731
1732         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1733
1734         indio_dev->chrdev.owner = this_mod;
1735
1736         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1737         if (ret < 0)
1738                 goto error_unreg_eventset;
1739
1740         return 0;
1741
1742 error_unreg_eventset:
1743         iio_device_unregister_eventset(indio_dev);
1744 error_free_sysfs:
1745         iio_device_unregister_sysfs(indio_dev);
1746 error_buffer_free_sysfs:
1747         iio_buffer_free_sysfs_and_mask(indio_dev);
1748 error_unreg_debugfs:
1749         iio_device_unregister_debugfs(indio_dev);
1750         return ret;
1751 }
1752 EXPORT_SYMBOL(__iio_device_register);
1753
1754 /**
1755  * iio_device_unregister() - unregister a device from the IIO subsystem
1756  * @indio_dev:          Device structure representing the device.
1757  **/
1758 void iio_device_unregister(struct iio_dev *indio_dev)
1759 {
1760         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1761
1762         mutex_lock(&indio_dev->info_exist_lock);
1763
1764         iio_device_unregister_debugfs(indio_dev);
1765
1766         iio_disable_all_buffers(indio_dev);
1767
1768         indio_dev->info = NULL;
1769
1770         iio_device_wakeup_eventset(indio_dev);
1771         iio_buffer_wakeup_poll(indio_dev);
1772
1773         mutex_unlock(&indio_dev->info_exist_lock);
1774
1775         iio_buffer_free_sysfs_and_mask(indio_dev);
1776 }
1777 EXPORT_SYMBOL(iio_device_unregister);
1778
1779 static void devm_iio_device_unreg(struct device *dev, void *res)
1780 {
1781         iio_device_unregister(*(struct iio_dev **)res);
1782 }
1783
1784 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1785                                struct module *this_mod)
1786 {
1787         struct iio_dev **ptr;
1788         int ret;
1789
1790         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1791         if (!ptr)
1792                 return -ENOMEM;
1793
1794         *ptr = indio_dev;
1795         ret = __iio_device_register(indio_dev, this_mod);
1796         if (!ret)
1797                 devres_add(dev, ptr);
1798         else
1799                 devres_free(ptr);
1800
1801         return ret;
1802 }
1803 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1804
1805 /**
1806  * iio_device_claim_direct_mode - Keep device in direct mode
1807  * @indio_dev:  the iio_dev associated with the device
1808  *
1809  * If the device is in direct mode it is guaranteed to stay
1810  * that way until iio_device_release_direct_mode() is called.
1811  *
1812  * Use with iio_device_release_direct_mode()
1813  *
1814  * Returns: 0 on success, -EBUSY on failure
1815  */
1816 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1817 {
1818         mutex_lock(&indio_dev->mlock);
1819
1820         if (iio_buffer_enabled(indio_dev)) {
1821                 mutex_unlock(&indio_dev->mlock);
1822                 return -EBUSY;
1823         }
1824         return 0;
1825 }
1826 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1827
1828 /**
1829  * iio_device_release_direct_mode - releases claim on direct mode
1830  * @indio_dev:  the iio_dev associated with the device
1831  *
1832  * Release the claim. Device is no longer guaranteed to stay
1833  * in direct mode.
1834  *
1835  * Use with iio_device_claim_direct_mode()
1836  */
1837 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1838 {
1839         mutex_unlock(&indio_dev->mlock);
1840 }
1841 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1842
1843 subsys_initcall(iio_init);
1844 module_exit(iio_exit);
1845
1846 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1847 MODULE_DESCRIPTION("Industrial I/O core");
1848 MODULE_LICENSE("GPL");