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 };
 165
 166 /**
 167  * iio_find_channel_from_si() - get channel from its scan index
 168  * @indio_dev:          device
 169  * @si:                 scan index to match
 170  */
 171 const struct iio_chan_spec
 172 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 173 {
 174         int i;
 175
 176         for (i = 0; i < indio_dev->num_channels; i++)
 177                 if (indio_dev->channels[i].scan_index == si)
 178                         return &indio_dev->channels[i];
 179         return NULL;
 180 }
 181
 182 /* This turns up an awful lot */
 183 ssize_t iio_read_const_attr(struct device *dev,
 184                             struct device_attribute *attr,
 185                             char *buf)
 186 {
 187         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 188 }
 189 EXPORT_SYMBOL(iio_read_const_attr);
 190
 191 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 192 {
 193         int ret;
 194         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 195
 196         ret = mutex_lock_interruptible(&indio_dev->mlock);
 197         if (ret)
 198                 return ret;
 199         if ((ev_int && iio_event_enabled(ev_int)) ||
 200             iio_buffer_enabled(indio_dev)) {
 201                 mutex_unlock(&indio_dev->mlock);
 202                 return -EBUSY;
 203         }
 204         indio_dev->clock_id = clock_id;
 205         mutex_unlock(&indio_dev->mlock);
 206
 207         return 0;
 208 }
 209
 210 /**
 211  * iio_get_time_ns() - utility function to get a time stamp for events etc
 212  * @indio_dev: device
 213  */
 214 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 215 {
 216         struct timespec64 tp;
 217
 218         switch (iio_device_get_clock(indio_dev)) {
 219         case CLOCK_REALTIME:
 220                 return ktime_get_real_ns();
 221         case CLOCK_MONOTONIC:
 222                 return ktime_get_ns();
 223         case CLOCK_MONOTONIC_RAW:
 224                 return ktime_get_raw_ns();
 225         case CLOCK_REALTIME_COARSE:
 226                 return ktime_to_ns(ktime_get_coarse_real());
 227         case CLOCK_MONOTONIC_COARSE:
 228                 ktime_get_coarse_ts64(&tp);
 229                 return timespec64_to_ns(&tp);
 230         case CLOCK_BOOTTIME:
 231                 return ktime_get_boot_ns();
 232         case CLOCK_TAI:
 233                 return ktime_get_tai_ns();
 234         default:
 235                 BUG();
 236         }
 237 }
 238 EXPORT_SYMBOL(iio_get_time_ns);
 239
 240 /**
 241  * iio_get_time_res() - utility function to get time stamp clock resolution in
 242  *                      nano seconds.
 243  * @indio_dev: device
 244  */
 245 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 246 {
 247         switch (iio_device_get_clock(indio_dev)) {
 248         case CLOCK_REALTIME:
 249         case CLOCK_MONOTONIC:
 250         case CLOCK_MONOTONIC_RAW:
 251         case CLOCK_BOOTTIME:
 252         case CLOCK_TAI:
 253                 return hrtimer_resolution;
 254         case CLOCK_REALTIME_COARSE:
 255         case CLOCK_MONOTONIC_COARSE:
 256                 return LOW_RES_NSEC;
 257         default:
 258                 BUG();
 259         }
 260 }
 261 EXPORT_SYMBOL(iio_get_time_res);
 262
 263 static int __init iio_init(void)
 264 {
 265         int ret;
 266
 267         /* Register sysfs bus */
 268         ret  = bus_register(&iio_bus_type);
 269         if (ret < 0) {
 270                 pr_err("could not register bus type\n");
 271                 goto error_nothing;
 272         }
 273
 274         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 275         if (ret < 0) {
 276                 pr_err("failed to allocate char dev region\n");
 277                 goto error_unregister_bus_type;
 278         }
 279
 280         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 281
 282         return 0;
 283
 284 error_unregister_bus_type:
 285         bus_unregister(&iio_bus_type);
 286 error_nothing:
 287         return ret;
 288 }
 289
 290 static void __exit iio_exit(void)
 291 {
 292         if (iio_devt)
 293                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 294         bus_unregister(&iio_bus_type);
 295         debugfs_remove(iio_debugfs_dentry);
 296 }
 297
 298 #if defined(CONFIG_DEBUG_FS)
 299 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 300                               size_t count, loff_t *ppos)
 301 {
 302         struct iio_dev *indio_dev = file->private_data;
 303         char buf[20];
 304         unsigned val = 0;
 305         ssize_t len;
 306         int ret;
 307
 308         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 309                                                   indio_dev->cached_reg_addr,
 310                                                   0, &val);
 311         if (ret) {
 312                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 313                 return ret;
 314         }
 315
 316         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 317
 318         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 319 }
 320
 321 static ssize_t iio_debugfs_write_reg(struct file *file,
 322                      const char __user *userbuf, size_t count, loff_t *ppos)
 323 {
 324         struct iio_dev *indio_dev = file->private_data;
 325         unsigned reg, val;
 326         char buf[80];
 327         int ret;
 328
 329         count = min_t(size_t, count, (sizeof(buf)-1));
 330         if (copy_from_user(buf, userbuf, count))
 331                 return -EFAULT;
 332
 333         buf[count] = 0;
 334
 335         ret = sscanf(buf, "%i %i", &reg, &val);
 336
 337         switch (ret) {
 338         case 1:
 339                 indio_dev->cached_reg_addr = reg;
 340                 break;
 341         case 2:
 342                 indio_dev->cached_reg_addr = reg;
 343                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 344                                                           val, NULL);
 345                 if (ret) {
 346                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 347                                 __func__);
 348                         return ret;
 349                 }
 350                 break;
 351         default:
 352                 return -EINVAL;
 353         }
 354
 355         return count;
 356 }
 357
 358 static const struct file_operations iio_debugfs_reg_fops = {
 359         .open = simple_open,
 360         .read = iio_debugfs_read_reg,
 361         .write = iio_debugfs_write_reg,
 362 };
 363
 364 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 365 {
 366         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 367 }
 368
 369 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 370 {
 371         struct dentry *d;
 372
 373         if (indio_dev->info->debugfs_reg_access == NULL)
 374                 return 0;
 375
 376         if (!iio_debugfs_dentry)
 377                 return 0;
 378
 379         indio_dev->debugfs_dentry =
 380                 debugfs_create_dir(dev_name(&indio_dev->dev),
 381                                    iio_debugfs_dentry);
 382         if (indio_dev->debugfs_dentry == NULL) {
 383                 dev_warn(indio_dev->dev.parent,
 384                          "Failed to create debugfs directory\n");
 385                 return -EFAULT;
 386         }
 387
 388         d = debugfs_create_file("direct_reg_access", 0644,
 389                                 indio_dev->debugfs_dentry,
 390                                 indio_dev, &iio_debugfs_reg_fops);
 391         if (!d) {
 392                 iio_device_unregister_debugfs(indio_dev);
 393                 return -ENOMEM;
 394         }
 395
 396         return 0;
 397 }
 398 #else
 399 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 400 {
 401         return 0;
 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 snprintf(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 snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 582                                         -vals[1], scale_db ? " dB" : "");
 583                 else
 584                         return snprintf(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 snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 589                                         -vals[1]);
 590                 else
 591                         return snprintf(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 snprintf(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 snprintf(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 += snprintf(&buf[l], len - l, "%d ", vals[i]);
 608                         if (l >= len)
 609                                 break;
 610                 }
 611                 return l;
 612         }
 613         default:
 614                 return 0;
 615         }
 616 }
 617
 618 /**
 619  * iio_format_value() - Formats a IIO value into its string representation
 620  * @buf:        The buffer to which the formatted value gets written
 621  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 622  * @type:       One of the IIO_VAL_* constants. This decides how the val
 623  *              and val2 parameters are formatted.
 624  * @size:       Number of IIO value entries contained in vals
 625  * @vals:       Pointer to the values, exact meaning depends on the
 626  *              type parameter.
 627  *
 628  * Return: 0 by default, a negative number on failure or the
 629  *         total number of characters written for a type that belongs
 630  *         to the IIO_VAL_* constant.
 631  */
 632 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 633 {
 634         ssize_t len;
 635
 636         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 637         if (len >= PAGE_SIZE - 1)
 638                 return -EFBIG;
 639
 640         return len + sprintf(buf + len, "\n");
 641 }
 642 EXPORT_SYMBOL_GPL(iio_format_value);
 643
 644 static ssize_t iio_read_channel_info(struct device *dev,
 645                                      struct device_attribute *attr,
 646                                      char *buf)
 647 {
 648         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 649         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 650         int vals[INDIO_MAX_RAW_ELEMENTS];
 651         int ret;
 652         int val_len = 2;
 653
 654         if (indio_dev->info->read_raw_multi)
 655                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 656                                                         INDIO_MAX_RAW_ELEMENTS,
 657                                                         vals, &val_len,
 658                                                         this_attr->address);
 659         else
 660                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 661                                     &vals[0], &vals[1], this_attr->address);
 662
 663         if (ret < 0)
 664                 return ret;
 665
 666         return iio_format_value(buf, ret, val_len, vals);
 667 }
 668
 669 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 670                                      int type, int length)
 671 {
 672         int i;
 673         ssize_t len = 0;
 674
 675         switch (type) {
 676         case IIO_VAL_INT:
 677                 for (i = 0; i < length; i++) {
 678                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 679                                                   type, 1, &vals[i]);
 680                         if (len >= PAGE_SIZE)
 681                                 return -EFBIG;
 682                         if (i < length - 1)
 683                                 len += snprintf(buf + len, PAGE_SIZE - len,
 684                                                 " ");
 685                         else
 686                                 len += snprintf(buf + len, PAGE_SIZE - len,
 687                                                 "\n");
 688                         if (len >= PAGE_SIZE)
 689                                 return -EFBIG;
 690                 }
 691                 break;
 692         default:
 693                 for (i = 0; i < length / 2; i++) {
 694                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 695                                                   type, 2, &vals[i * 2]);
 696                         if (len >= PAGE_SIZE)
 697                                 return -EFBIG;
 698                         if (i < length / 2 - 1)
 699                                 len += snprintf(buf + len, PAGE_SIZE - len,
 700                                                 " ");
 701                         else
 702                                 len += snprintf(buf + len, PAGE_SIZE - len,
 703                                                 "\n");
 704                         if (len >= PAGE_SIZE)
 705                                 return -EFBIG;
 706                 }
 707         }
 708
 709         return len;
 710 }
 711
 712 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 713 {
 714         int i;
 715         ssize_t len;
 716
 717         len = snprintf(buf, PAGE_SIZE, "[");
 718         switch (type) {
 719         case IIO_VAL_INT:
 720                 for (i = 0; i < 3; i++) {
 721                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 722                                                   type, 1, &vals[i]);
 723                         if (len >= PAGE_SIZE)
 724                                 return -EFBIG;
 725                         if (i < 2)
 726                                 len += snprintf(buf + len, PAGE_SIZE - len,
 727                                                 " ");
 728                         else
 729                                 len += snprintf(buf + len, PAGE_SIZE - len,
 730                                                 "]\n");
 731                         if (len >= PAGE_SIZE)
 732                                 return -EFBIG;
 733                 }
 734                 break;
 735         default:
 736                 for (i = 0; i < 3; i++) {
 737                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 738                                                   type, 2, &vals[i * 2]);
 739                         if (len >= PAGE_SIZE)
 740                                 return -EFBIG;
 741                         if (i < 2)
 742                                 len += snprintf(buf + len, PAGE_SIZE - len,
 743                                                 " ");
 744                         else
 745                                 len += snprintf(buf + len, PAGE_SIZE - len,
 746                                                 "]\n");
 747                         if (len >= PAGE_SIZE)
 748                                 return -EFBIG;
 749                 }
 750         }
 751
 752         return len;
 753 }
 754
 755 static ssize_t iio_read_channel_info_avail(struct device *dev,
 756                                            struct device_attribute *attr,
 757                                            char *buf)
 758 {
 759         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 760         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 761         const int *vals;
 762         int ret;
 763         int length;
 764         int type;
 765
 766         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 767                                           &vals, &type, &length,
 768                                           this_attr->address);
 769
 770         if (ret < 0)
 771                 return ret;
 772         switch (ret) {
 773         case IIO_AVAIL_LIST:
 774                 return iio_format_avail_list(buf, vals, type, length);
 775         case IIO_AVAIL_RANGE:
 776                 return iio_format_avail_range(buf, vals, type);
 777         default:
 778                 return -EINVAL;
 779         }
 780 }
 781
 782 /**
 783  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 784  * @str: The string to parse
 785  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 786  * @integer: The integer part of the number
 787  * @fract: The fractional part of the number
 788  *
 789  * Returns 0 on success, or a negative error code if the string could not be
 790  * parsed.
 791  */
 792 int iio_str_to_fixpoint(const char *str, int fract_mult,
 793         int *integer, int *fract)
 794 {
 795         int i = 0, f = 0;
 796         bool integer_part = true, negative = false;
 797
 798         if (fract_mult == 0) {
 799                 *fract = 0;
 800
 801                 return kstrtoint(str, 0, integer);
 802         }
 803
 804         if (str[0] == '-') {
 805                 negative = true;
 806                 str++;
 807         } else if (str[0] == '+') {
 808                 str++;
 809         }
 810
 811         while (*str) {
 812                 if ('0' <= *str && *str <= '9') {
 813                         if (integer_part) {
 814                                 i = i * 10 + *str - '0';
 815                         } else {
 816                                 f += fract_mult * (*str - '0');
 817                                 fract_mult /= 10;
 818                         }
 819                 } else if (*str == '\n') {
 820                         if (*(str + 1) == '\0')
 821                                 break;
 822                         else
 823                                 return -EINVAL;
 824                 } else if (*str == '.' && integer_part) {
 825                         integer_part = false;
 826                 } else {
 827                         return -EINVAL;
 828                 }
 829                 str++;
 830         }
 831
 832         if (negative) {
 833                 if (i)
 834                         i = -i;
 835                 else
 836                         f = -f;
 837         }
 838
 839         *integer = i;
 840         *fract = f;
 841
 842         return 0;
 843 }
 844 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 845
 846 static ssize_t iio_write_channel_info(struct device *dev,
 847                                       struct device_attribute *attr,
 848                                       const char *buf,
 849                                       size_t len)
 850 {
 851         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 852         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 853         int ret, fract_mult = 100000;
 854         int integer, fract;
 855
 856         /* Assumes decimal - precision based on number of digits */
 857         if (!indio_dev->info->write_raw)
 858                 return -EINVAL;
 859
 860         if (indio_dev->info->write_raw_get_fmt)
 861                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 862                         this_attr->c, this_attr->address)) {
 863                 case IIO_VAL_INT:
 864                         fract_mult = 0;
 865                         break;
 866                 case IIO_VAL_INT_PLUS_MICRO:
 867                         fract_mult = 100000;
 868                         break;
 869                 case IIO_VAL_INT_PLUS_NANO:
 870                         fract_mult = 100000000;
 871                         break;
 872                 default:
 873                         return -EINVAL;
 874                 }
 875
 876         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 877         if (ret)
 878                 return ret;
 879
 880         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 881                                          integer, fract, this_attr->address);
 882         if (ret)
 883                 return ret;
 884
 885         return len;
 886 }
 887
 888 static
 889 int __iio_device_attr_init(struct device_attribute *dev_attr,
 890                            const char *postfix,
 891                            struct iio_chan_spec const *chan,
 892                            ssize_t (*readfunc)(struct device *dev,
 893                                                struct device_attribute *attr,
 894                                                char *buf),
 895                            ssize_t (*writefunc)(struct device *dev,
 896                                                 struct device_attribute *attr,
 897                                                 const char *buf,
 898                                                 size_t len),
 899                            enum iio_shared_by shared_by)
 900 {
 901         int ret = 0;
 902         char *name = NULL;
 903         char *full_postfix;
 904         sysfs_attr_init(&dev_attr->attr);
 905
 906         /* Build up postfix of <extend_name>_<modifier>_postfix */
 907         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 908                 if (chan->extend_name)
 909                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 910                                                  iio_modifier_names[chan
 911                                                                     ->channel2],
 912                                                  chan->extend_name,
 913                                                  postfix);
 914                 else
 915                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 916                                                  iio_modifier_names[chan
 917                                                                     ->channel2],
 918                                                  postfix);
 919         } else {
 920                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 921                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 922                 else
 923                         full_postfix = kasprintf(GFP_KERNEL,
 924                                                  "%s_%s",
 925                                                  chan->extend_name,
 926                                                  postfix);
 927         }
 928         if (full_postfix == NULL)
 929                 return -ENOMEM;
 930
 931         if (chan->differential) { /* Differential can not have modifier */
 932                 switch (shared_by) {
 933                 case IIO_SHARED_BY_ALL:
 934                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 935                         break;
 936                 case IIO_SHARED_BY_DIR:
 937                         name = kasprintf(GFP_KERNEL, "%s_%s",
 938                                                 iio_direction[chan->output],
 939                                                 full_postfix);
 940                         break;
 941                 case IIO_SHARED_BY_TYPE:
 942                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 943                                             iio_direction[chan->output],
 944                                             iio_chan_type_name_spec[chan->type],
 945                                             iio_chan_type_name_spec[chan->type],
 946                                             full_postfix);
 947                         break;
 948                 case IIO_SEPARATE:
 949                         if (!chan->indexed) {
 950                                 WARN(1, "Differential channels must be indexed\n");
 951                                 ret = -EINVAL;
 952                                 goto error_free_full_postfix;
 953                         }
 954                         name = kasprintf(GFP_KERNEL,
 955                                             "%s_%s%d-%s%d_%s",
 956                                             iio_direction[chan->output],
 957                                             iio_chan_type_name_spec[chan->type],
 958                                             chan->channel,
 959                                             iio_chan_type_name_spec[chan->type],
 960                                             chan->channel2,
 961                                             full_postfix);
 962                         break;
 963                 }
 964         } else { /* Single ended */
 965                 switch (shared_by) {
 966                 case IIO_SHARED_BY_ALL:
 967                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 968                         break;
 969                 case IIO_SHARED_BY_DIR:
 970                         name = kasprintf(GFP_KERNEL, "%s_%s",
 971                                                 iio_direction[chan->output],
 972                                                 full_postfix);
 973                         break;
 974                 case IIO_SHARED_BY_TYPE:
 975                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 976                                             iio_direction[chan->output],
 977                                             iio_chan_type_name_spec[chan->type],
 978                                             full_postfix);
 979                         break;
 980
 981                 case IIO_SEPARATE:
 982                         if (chan->indexed)
 983                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 984                                                     iio_direction[chan->output],
 985                                                     iio_chan_type_name_spec[chan->type],
 986                                                     chan->channel,
 987                                                     full_postfix);
 988                         else
 989                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 990                                                     iio_direction[chan->output],
 991                                                     iio_chan_type_name_spec[chan->type],
 992                                                     full_postfix);
 993                         break;
 994                 }
 995         }
 996         if (name == NULL) {
 997                 ret = -ENOMEM;
 998                 goto error_free_full_postfix;
 999         }
1000         dev_attr->attr.name = name;
1001
1002         if (readfunc) {
1003                 dev_attr->attr.mode |= S_IRUGO;
1004                 dev_attr->show = readfunc;
1005         }
1006
1007         if (writefunc) {
1008                 dev_attr->attr.mode |= S_IWUSR;
1009                 dev_attr->store = writefunc;
1010         }
1011
1012 error_free_full_postfix:
1013         kfree(full_postfix);
1014
1015         return ret;
1016 }
1017
1018 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1019 {
1020         kfree(dev_attr->attr.name);
1021 }
1022
1023 int __iio_add_chan_devattr(const char *postfix,
1024                            struct iio_chan_spec const *chan,
1025                            ssize_t (*readfunc)(struct device *dev,
1026                                                struct device_attribute *attr,
1027                                                char *buf),
1028                            ssize_t (*writefunc)(struct device *dev,
1029                                                 struct device_attribute *attr,
1030                                                 const char *buf,
1031                                                 size_t len),
1032                            u64 mask,
1033                            enum iio_shared_by shared_by,
1034                            struct device *dev,
1035                            struct list_head *attr_list)
1036 {
1037         int ret;
1038         struct iio_dev_attr *iio_attr, *t;
1039
1040         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1041         if (iio_attr == NULL)
1042                 return -ENOMEM;
1043         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1044                                      postfix, chan,
1045                                      readfunc, writefunc, shared_by);
1046         if (ret)
1047                 goto error_iio_dev_attr_free;
1048         iio_attr->c = chan;
1049         iio_attr->address = mask;
1050         list_for_each_entry(t, attr_list, l)
1051                 if (strcmp(t->dev_attr.attr.name,
1052                            iio_attr->dev_attr.attr.name) == 0) {
1053                         if (shared_by == IIO_SEPARATE)
1054                                 dev_err(dev, "tried to double register : %s\n",
1055                                         t->dev_attr.attr.name);
1056                         ret = -EBUSY;
1057                         goto error_device_attr_deinit;
1058                 }
1059         list_add(&iio_attr->l, attr_list);
1060
1061         return 0;
1062
1063 error_device_attr_deinit:
1064         __iio_device_attr_deinit(&iio_attr->dev_attr);
1065 error_iio_dev_attr_free:
1066         kfree(iio_attr);
1067         return ret;
1068 }
1069
1070 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1071                                          struct iio_chan_spec const *chan,
1072                                          enum iio_shared_by shared_by,
1073                                          const long *infomask)
1074 {
1075         int i, ret, attrcount = 0;
1076
1077         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1078                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1079                         return -EINVAL;
1080                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1081                                              chan,
1082                                              &iio_read_channel_info,
1083                                              &iio_write_channel_info,
1084                                              i,
1085                                              shared_by,
1086                                              &indio_dev->dev,
1087                                              &indio_dev->channel_attr_list);
1088                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1089                         continue;
1090                 else if (ret < 0)
1091                         return ret;
1092                 attrcount++;
1093         }
1094
1095         return attrcount;
1096 }
1097
1098 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1099                                                struct iio_chan_spec const *chan,
1100                                                enum iio_shared_by shared_by,
1101                                                const long *infomask)
1102 {
1103         int i, ret, attrcount = 0;
1104         char *avail_postfix;
1105
1106         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1107                 avail_postfix = kasprintf(GFP_KERNEL,
1108                                           "%s_available",
1109                                           iio_chan_info_postfix[i]);
1110                 if (!avail_postfix)
1111                         return -ENOMEM;
1112
1113                 ret = __iio_add_chan_devattr(avail_postfix,
1114                                              chan,
1115                                              &iio_read_channel_info_avail,
1116                                              NULL,
1117                                              i,
1118                                              shared_by,
1119                                              &indio_dev->dev,
1120                                              &indio_dev->channel_attr_list);
1121                 kfree(avail_postfix);
1122                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1123                         continue;
1124                 else if (ret < 0)
1125                         return ret;
1126                 attrcount++;
1127         }
1128
1129         return attrcount;
1130 }
1131
1132 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1133                                         struct iio_chan_spec const *chan)
1134 {
1135         int ret, attrcount = 0;
1136         const struct iio_chan_spec_ext_info *ext_info;
1137
1138         if (chan->channel < 0)
1139                 return 0;
1140         ret = iio_device_add_info_mask_type(indio_dev, chan,
1141                                             IIO_SEPARATE,
1142                                             &chan->info_mask_separate);
1143         if (ret < 0)
1144                 return ret;
1145         attrcount += ret;
1146
1147         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1148                                                   IIO_SEPARATE,
1149                                                   &chan->
1150                                                   info_mask_separate_available);
1151         if (ret < 0)
1152                 return ret;
1153         attrcount += ret;
1154
1155         ret = iio_device_add_info_mask_type(indio_dev, chan,
1156                                             IIO_SHARED_BY_TYPE,
1157                                             &chan->info_mask_shared_by_type);
1158         if (ret < 0)
1159                 return ret;
1160         attrcount += ret;
1161
1162         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1163                                                   IIO_SHARED_BY_TYPE,
1164                                                   &chan->
1165                                                   info_mask_shared_by_type_available);
1166         if (ret < 0)
1167                 return ret;
1168         attrcount += ret;
1169
1170         ret = iio_device_add_info_mask_type(indio_dev, chan,
1171                                             IIO_SHARED_BY_DIR,
1172                                             &chan->info_mask_shared_by_dir);
1173         if (ret < 0)
1174                 return ret;
1175         attrcount += ret;
1176
1177         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1178                                                   IIO_SHARED_BY_DIR,
1179                                                   &chan->info_mask_shared_by_dir_available);
1180         if (ret < 0)
1181                 return ret;
1182         attrcount += ret;
1183
1184         ret = iio_device_add_info_mask_type(indio_dev, chan,
1185                                             IIO_SHARED_BY_ALL,
1186                                             &chan->info_mask_shared_by_all);
1187         if (ret < 0)
1188                 return ret;
1189         attrcount += ret;
1190
1191         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1192                                                   IIO_SHARED_BY_ALL,
1193                                                   &chan->info_mask_shared_by_all_available);
1194         if (ret < 0)
1195                 return ret;
1196         attrcount += ret;
1197
1198         if (chan->ext_info) {
1199                 unsigned int i = 0;
1200                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1201                         ret = __iio_add_chan_devattr(ext_info->name,
1202                                         chan,
1203                                         ext_info->read ?
1204                                             &iio_read_channel_ext_info : NULL,
1205                                         ext_info->write ?
1206                                             &iio_write_channel_ext_info : NULL,
1207                                         i,
1208                                         ext_info->shared,
1209                                         &indio_dev->dev,
1210                                         &indio_dev->channel_attr_list);
1211                         i++;
1212                         if (ret == -EBUSY && ext_info->shared)
1213                                 continue;
1214
1215                         if (ret)
1216                                 return ret;
1217
1218                         attrcount++;
1219                 }
1220         }
1221
1222         return attrcount;
1223 }
1224
1225 /**
1226  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1227  * @attr_list: List of IIO device attributes
1228  *
1229  * This function frees the memory allocated for each of the IIO device
1230  * attributes in the list.
1231  */
1232 void iio_free_chan_devattr_list(struct list_head *attr_list)
1233 {
1234         struct iio_dev_attr *p, *n;
1235
1236         list_for_each_entry_safe(p, n, attr_list, l) {
1237                 kfree(p->dev_attr.attr.name);
1238                 list_del(&p->l);
1239                 kfree(p);
1240         }
1241 }
1242
1243 static ssize_t iio_show_dev_name(struct device *dev,
1244                                  struct device_attribute *attr,
1245                                  char *buf)
1246 {
1247         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1248         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1249 }
1250
1251 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1252
1253 static ssize_t iio_show_timestamp_clock(struct device *dev,
1254                                         struct device_attribute *attr,
1255                                         char *buf)
1256 {
1257         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1258         const clockid_t clk = iio_device_get_clock(indio_dev);
1259         const char *name;
1260         ssize_t sz;
1261
1262         switch (clk) {
1263         case CLOCK_REALTIME:
1264                 name = "realtime\n";
1265                 sz = sizeof("realtime\n");
1266                 break;
1267         case CLOCK_MONOTONIC:
1268                 name = "monotonic\n";
1269                 sz = sizeof("monotonic\n");
1270                 break;
1271         case CLOCK_MONOTONIC_RAW:
1272                 name = "monotonic_raw\n";
1273                 sz = sizeof("monotonic_raw\n");
1274                 break;
1275         case CLOCK_REALTIME_COARSE:
1276                 name = "realtime_coarse\n";
1277                 sz = sizeof("realtime_coarse\n");
1278                 break;
1279         case CLOCK_MONOTONIC_COARSE:
1280                 name = "monotonic_coarse\n";
1281                 sz = sizeof("monotonic_coarse\n");
1282                 break;
1283         case CLOCK_BOOTTIME:
1284                 name = "boottime\n";
1285                 sz = sizeof("boottime\n");
1286                 break;
1287         case CLOCK_TAI:
1288                 name = "tai\n";
1289                 sz = sizeof("tai\n");
1290                 break;
1291         default:
1292                 BUG();
1293         }
1294
1295         memcpy(buf, name, sz);
1296         return sz;
1297 }
1298
1299 static ssize_t iio_store_timestamp_clock(struct device *dev,
1300                                          struct device_attribute *attr,
1301                                          const char *buf, size_t len)
1302 {
1303         clockid_t clk;
1304         int ret;
1305
1306         if (sysfs_streq(buf, "realtime"))
1307                 clk = CLOCK_REALTIME;
1308         else if (sysfs_streq(buf, "monotonic"))
1309                 clk = CLOCK_MONOTONIC;
1310         else if (sysfs_streq(buf, "monotonic_raw"))
1311                 clk = CLOCK_MONOTONIC_RAW;
1312         else if (sysfs_streq(buf, "realtime_coarse"))
1313                 clk = CLOCK_REALTIME_COARSE;
1314         else if (sysfs_streq(buf, "monotonic_coarse"))
1315                 clk = CLOCK_MONOTONIC_COARSE;
1316         else if (sysfs_streq(buf, "boottime"))
1317                 clk = CLOCK_BOOTTIME;
1318         else if (sysfs_streq(buf, "tai"))
1319                 clk = CLOCK_TAI;
1320         else
1321                 return -EINVAL;
1322
1323         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1324         if (ret)
1325                 return ret;
1326
1327         return len;
1328 }
1329
1330 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1331                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1332
1333 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1334 {
1335         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1336         struct iio_dev_attr *p;
1337         struct attribute **attr, *clk = NULL;
1338
1339         /* First count elements in any existing group */
1340         if (indio_dev->info->attrs) {
1341                 attr = indio_dev->info->attrs->attrs;
1342                 while (*attr++ != NULL)
1343                         attrcount_orig++;
1344         }
1345         attrcount = attrcount_orig;
1346         /*
1347          * New channel registration method - relies on the fact a group does
1348          * not need to be initialized if its name is NULL.
1349          */
1350         if (indio_dev->channels)
1351                 for (i = 0; i < indio_dev->num_channels; i++) {
1352                         const struct iio_chan_spec *chan =
1353                                 &indio_dev->channels[i];
1354
1355                         if (chan->type == IIO_TIMESTAMP)
1356                                 clk = &dev_attr_current_timestamp_clock.attr;
1357
1358                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1359                         if (ret < 0)
1360                                 goto error_clear_attrs;
1361                         attrcount += ret;
1362                 }
1363
1364         if (indio_dev->event_interface)
1365                 clk = &dev_attr_current_timestamp_clock.attr;
1366
1367         if (indio_dev->name)
1368                 attrcount++;
1369         if (clk)
1370                 attrcount++;
1371
1372         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1373                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1374                                                    GFP_KERNEL);
1375         if (indio_dev->chan_attr_group.attrs == NULL) {
1376                 ret = -ENOMEM;
1377                 goto error_clear_attrs;
1378         }
1379         /* Copy across original attributes */
1380         if (indio_dev->info->attrs)
1381                 memcpy(indio_dev->chan_attr_group.attrs,
1382                        indio_dev->info->attrs->attrs,
1383                        sizeof(indio_dev->chan_attr_group.attrs[0])
1384                        *attrcount_orig);
1385         attrn = attrcount_orig;
1386         /* Add all elements from the list. */
1387         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1388                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1389         if (indio_dev->name)
1390                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1391         if (clk)
1392                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1393
1394         indio_dev->groups[indio_dev->groupcounter++] =
1395                 &indio_dev->chan_attr_group;
1396
1397         return 0;
1398
1399 error_clear_attrs:
1400         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1401
1402         return ret;
1403 }
1404
1405 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1406 {
1407
1408         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1409         kfree(indio_dev->chan_attr_group.attrs);
1410         indio_dev->chan_attr_group.attrs = NULL;
1411 }
1412
1413 static void iio_dev_release(struct device *device)
1414 {
1415         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1416         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1417                 iio_device_unregister_trigger_consumer(indio_dev);
1418         iio_device_unregister_eventset(indio_dev);
1419         iio_device_unregister_sysfs(indio_dev);
1420
1421         iio_buffer_put(indio_dev->buffer);
1422
1423         ida_simple_remove(&iio_ida, indio_dev->id);
1424         kfree(indio_dev);
1425 }
1426
1427 struct device_type iio_device_type = {
1428         .name = "iio_device",
1429         .release = iio_dev_release,
1430 };
1431
1432 /**
1433  * iio_device_alloc() - allocate an iio_dev from a driver
1434  * @sizeof_priv:        Space to allocate for private structure.
1435  **/
1436 struct iio_dev *iio_device_alloc(int sizeof_priv)
1437 {
1438         struct iio_dev *dev;
1439         size_t alloc_size;
1440
1441         alloc_size = sizeof(struct iio_dev);
1442         if (sizeof_priv) {
1443                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1444                 alloc_size += sizeof_priv;
1445         }
1446         /* ensure 32-byte alignment of whole construct ? */
1447         alloc_size += IIO_ALIGN - 1;
1448
1449         dev = kzalloc(alloc_size, GFP_KERNEL);
1450
1451         if (dev) {
1452                 dev->dev.groups = dev->groups;
1453                 dev->dev.type = &iio_device_type;
1454                 dev->dev.bus = &iio_bus_type;
1455                 device_initialize(&dev->dev);
1456                 dev_set_drvdata(&dev->dev, (void *)dev);
1457                 mutex_init(&dev->mlock);
1458                 mutex_init(&dev->info_exist_lock);
1459                 INIT_LIST_HEAD(&dev->channel_attr_list);
1460
1461                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1462                 if (dev->id < 0) {
1463                         /* cannot use a dev_err as the name isn't available */
1464                         pr_err("failed to get device id\n");
1465                         kfree(dev);
1466                         return NULL;
1467                 }
1468                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1469                 INIT_LIST_HEAD(&dev->buffer_list);
1470         }
1471
1472         return dev;
1473 }
1474 EXPORT_SYMBOL(iio_device_alloc);
1475
1476 /**
1477  * iio_device_free() - free an iio_dev from a driver
1478  * @dev:                the iio_dev associated with the device
1479  **/
1480 void iio_device_free(struct iio_dev *dev)
1481 {
1482         if (dev)
1483                 put_device(&dev->dev);
1484 }
1485 EXPORT_SYMBOL(iio_device_free);
1486
1487 static void devm_iio_device_release(struct device *dev, void *res)
1488 {
1489         iio_device_free(*(struct iio_dev **)res);
1490 }
1491
1492 int devm_iio_device_match(struct device *dev, void *res, void *data)
1493 {
1494         struct iio_dev **r = res;
1495         if (!r || !*r) {
1496                 WARN_ON(!r || !*r);
1497                 return 0;
1498         }
1499         return *r == data;
1500 }
1501 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1502
1503 /**
1504  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1505  * @dev:                Device to allocate iio_dev for
1506  * @sizeof_priv:        Space to allocate for private structure.
1507  *
1508  * Managed iio_device_alloc. iio_dev allocated with this function is
1509  * automatically freed on driver detach.
1510  *
1511  * If an iio_dev allocated with this function needs to be freed separately,
1512  * devm_iio_device_free() must be used.
1513  *
1514  * RETURNS:
1515  * Pointer to allocated iio_dev on success, NULL on failure.
1516  */
1517 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1518 {
1519         struct iio_dev **ptr, *iio_dev;
1520
1521         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1522                            GFP_KERNEL);
1523         if (!ptr)
1524                 return NULL;
1525
1526         iio_dev = iio_device_alloc(sizeof_priv);
1527         if (iio_dev) {
1528                 *ptr = iio_dev;
1529                 devres_add(dev, ptr);
1530         } else {
1531                 devres_free(ptr);
1532         }
1533
1534         return iio_dev;
1535 }
1536 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1537
1538 /**
1539  * devm_iio_device_free - Resource-managed iio_device_free()
1540  * @dev:                Device this iio_dev belongs to
1541  * @iio_dev:            the iio_dev associated with the device
1542  *
1543  * Free iio_dev allocated with devm_iio_device_alloc().
1544  */
1545 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1546 {
1547         int rc;
1548
1549         rc = devres_release(dev, devm_iio_device_release,
1550                             devm_iio_device_match, iio_dev);
1551         WARN_ON(rc);
1552 }
1553 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1554
1555 /**
1556  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1557  * @inode:      Inode structure for identifying the device in the file system
1558  * @filp:       File structure for iio device used to keep and later access
1559  *              private data
1560  *
1561  * Return: 0 on success or -EBUSY if the device is already opened
1562  **/
1563 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1564 {
1565         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1566                                                 struct iio_dev, chrdev);
1567
1568         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1569                 return -EBUSY;
1570
1571         iio_device_get(indio_dev);
1572
1573         filp->private_data = indio_dev;
1574
1575         return 0;
1576 }
1577
1578 /**
1579  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1580  * @inode:      Inode structure pointer for the char device
1581  * @filp:       File structure pointer for the char device
1582  *
1583  * Return: 0 for successful release
1584  */
1585 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1586 {
1587         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1588                                                 struct iio_dev, chrdev);
1589         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1590         iio_device_put(indio_dev);
1591
1592         return 0;
1593 }
1594
1595 /* Somewhat of a cross file organization violation - ioctls here are actually
1596  * event related */
1597 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1598 {
1599         struct iio_dev *indio_dev = filp->private_data;
1600         int __user *ip = (int __user *)arg;
1601         int fd;
1602
1603         if (!indio_dev->info)
1604                 return -ENODEV;
1605
1606         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1607                 fd = iio_event_getfd(indio_dev);
1608                 if (fd < 0)
1609                         return fd;
1610                 if (copy_to_user(ip, &fd, sizeof(fd)))
1611                         return -EFAULT;
1612                 return 0;
1613         }
1614         return -EINVAL;
1615 }
1616
1617 static const struct file_operations iio_buffer_fileops = {
1618         .read = iio_buffer_read_first_n_outer_addr,
1619         .release = iio_chrdev_release,
1620         .open = iio_chrdev_open,
1621         .poll = iio_buffer_poll_addr,
1622         .owner = THIS_MODULE,
1623         .llseek = noop_llseek,
1624         .unlocked_ioctl = iio_ioctl,
1625         .compat_ioctl = iio_ioctl,
1626 };
1627
1628 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1629 {
1630         int i, j;
1631         const struct iio_chan_spec *channels = indio_dev->channels;
1632
1633         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1634                 return 0;
1635
1636         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1637                 if (channels[i].scan_index < 0)
1638                         continue;
1639                 for (j = i + 1; j < indio_dev->num_channels; j++)
1640                         if (channels[i].scan_index == channels[j].scan_index) {
1641                                 dev_err(&indio_dev->dev,
1642                                         "Duplicate scan index %d\n",
1643                                         channels[i].scan_index);
1644                                 return -EINVAL;
1645                         }
1646         }
1647
1648         return 0;
1649 }
1650
1651 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1652
1653 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1654 {
1655         int ret;
1656
1657         indio_dev->driver_module = this_mod;
1658         /* If the calling driver did not initialize of_node, do it here */
1659         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1660                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1661
1662         ret = iio_check_unique_scan_index(indio_dev);
1663         if (ret < 0)
1664                 return ret;
1665
1666         if (!indio_dev->info)
1667                 return -EINVAL;
1668
1669         /* configure elements for the chrdev */
1670         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1671
1672         ret = iio_device_register_debugfs(indio_dev);
1673         if (ret) {
1674                 dev_err(indio_dev->dev.parent,
1675                         "Failed to register debugfs interfaces\n");
1676                 return ret;
1677         }
1678
1679         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1680         if (ret) {
1681                 dev_err(indio_dev->dev.parent,
1682                         "Failed to create buffer sysfs interfaces\n");
1683                 goto error_unreg_debugfs;
1684         }
1685
1686         ret = iio_device_register_sysfs(indio_dev);
1687         if (ret) {
1688                 dev_err(indio_dev->dev.parent,
1689                         "Failed to register sysfs interfaces\n");
1690                 goto error_buffer_free_sysfs;
1691         }
1692         ret = iio_device_register_eventset(indio_dev);
1693         if (ret) {
1694                 dev_err(indio_dev->dev.parent,
1695                         "Failed to register event set\n");
1696                 goto error_free_sysfs;
1697         }
1698         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1699                 iio_device_register_trigger_consumer(indio_dev);
1700
1701         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1702                 indio_dev->setup_ops == NULL)
1703                 indio_dev->setup_ops = &noop_ring_setup_ops;
1704
1705         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1706
1707         indio_dev->chrdev.owner = this_mod;
1708
1709         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1710         if (ret < 0)
1711                 goto error_unreg_eventset;
1712
1713         return 0;
1714
1715 error_unreg_eventset:
1716         iio_device_unregister_eventset(indio_dev);
1717 error_free_sysfs:
1718         iio_device_unregister_sysfs(indio_dev);
1719 error_buffer_free_sysfs:
1720         iio_buffer_free_sysfs_and_mask(indio_dev);
1721 error_unreg_debugfs:
1722         iio_device_unregister_debugfs(indio_dev);
1723         return ret;
1724 }
1725 EXPORT_SYMBOL(__iio_device_register);
1726
1727 /**
1728  * iio_device_unregister() - unregister a device from the IIO subsystem
1729  * @indio_dev:          Device structure representing the device.
1730  **/
1731 void iio_device_unregister(struct iio_dev *indio_dev)
1732 {
1733         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1734
1735         mutex_lock(&indio_dev->info_exist_lock);
1736
1737         iio_device_unregister_debugfs(indio_dev);
1738
1739         iio_disable_all_buffers(indio_dev);
1740
1741         indio_dev->info = NULL;
1742
1743         iio_device_wakeup_eventset(indio_dev);
1744         iio_buffer_wakeup_poll(indio_dev);
1745
1746         mutex_unlock(&indio_dev->info_exist_lock);
1747
1748         iio_buffer_free_sysfs_and_mask(indio_dev);
1749 }
1750 EXPORT_SYMBOL(iio_device_unregister);
1751
1752 static void devm_iio_device_unreg(struct device *dev, void *res)
1753 {
1754         iio_device_unregister(*(struct iio_dev **)res);
1755 }
1756
1757 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1758                                struct module *this_mod)
1759 {
1760         struct iio_dev **ptr;
1761         int ret;
1762
1763         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1764         if (!ptr)
1765                 return -ENOMEM;
1766
1767         *ptr = indio_dev;
1768         ret = __iio_device_register(indio_dev, this_mod);
1769         if (!ret)
1770                 devres_add(dev, ptr);
1771         else
1772                 devres_free(ptr);
1773
1774         return ret;
1775 }
1776 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1777
1778 /**
1779  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1780  * @dev:        Device this iio_dev belongs to
1781  * @indio_dev:  the iio_dev associated with the device
1782  *
1783  * Unregister iio_dev registered with devm_iio_device_register().
1784  */
1785 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1786 {
1787         int rc;
1788
1789         rc = devres_release(dev, devm_iio_device_unreg,
1790                             devm_iio_device_match, indio_dev);
1791         WARN_ON(rc);
1792 }
1793 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1794
1795 /**
1796  * iio_device_claim_direct_mode - Keep device in direct mode
1797  * @indio_dev:  the iio_dev associated with the device
1798  *
1799  * If the device is in direct mode it is guaranteed to stay
1800  * that way until iio_device_release_direct_mode() is called.
1801  *
1802  * Use with iio_device_release_direct_mode()
1803  *
1804  * Returns: 0 on success, -EBUSY on failure
1805  */
1806 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1807 {
1808         mutex_lock(&indio_dev->mlock);
1809
1810         if (iio_buffer_enabled(indio_dev)) {
1811                 mutex_unlock(&indio_dev->mlock);
1812                 return -EBUSY;
1813         }
1814         return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1817
1818 /**
1819  * iio_device_release_direct_mode - releases claim on direct mode
1820  * @indio_dev:  the iio_dev associated with the device
1821  *
1822  * Release the claim. Device is no longer guaranteed to stay
1823  * in direct mode.
1824  *
1825  * Use with iio_device_claim_direct_mode()
1826  */
1827 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1828 {
1829         mutex_unlock(&indio_dev->mlock);
1830 }
1831 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1832
1833 subsys_initcall(iio_init);
1834 module_exit(iio_exit);
1835
1836 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1837 MODULE_DESCRIPTION("Industrial I/O core");
1838 MODULE_LICENSE("GPL");