drivers/iio/industrialio-core.c

   1 /* The industrial I/O core
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * Based on elements of hwmon and input subsystems.
  10  */
  11
  12 #define pr_fmt(fmt) "iio-core: " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/idr.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19 #include <linux/device.h>
  20 #include <linux/fs.h>
  21 #include <linux/poll.h>
  22 #include <linux/property.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25 #include <linux/cdev.h>
  26 #include <linux/slab.h>
  27 #include <linux/anon_inodes.h>
  28 #include <linux/debugfs.h>
  29 #include <linux/mutex.h>
  30 #include <linux/iio/iio.h>
  31 #include "iio_core.h"
  32 #include "iio_core_trigger.h"
  33 #include <linux/iio/sysfs.h>
  34 #include <linux/iio/events.h>
  35 #include <linux/iio/buffer.h>
  36 #include <linux/iio/buffer_impl.h>
  37
  38 /* IDA to assign each registered device a unique id */
  39 static DEFINE_IDA(iio_ida);
  40
  41 static dev_t iio_devt;
  42
  43 #define IIO_DEV_MAX 256
  44 struct bus_type iio_bus_type = {
  45         .name = "iio",
  46 };
  47 EXPORT_SYMBOL(iio_bus_type);
  48
  49 static struct dentry *iio_debugfs_dentry;
  50
  51 static const char * const iio_direction[] = {
  52         [0] = "in",
  53         [1] = "out",
  54 };
  55
  56 static const char * const iio_chan_type_name_spec[] = {
  57         [IIO_VOLTAGE] = "voltage",
  58         [IIO_CURRENT] = "current",
  59         [IIO_POWER] = "power",
  60         [IIO_ACCEL] = "accel",
  61         [IIO_ANGL_VEL] = "anglvel",
  62         [IIO_MAGN] = "magn",
  63         [IIO_LIGHT] = "illuminance",
  64         [IIO_INTENSITY] = "intensity",
  65         [IIO_PROXIMITY] = "proximity",
  66         [IIO_TEMP] = "temp",
  67         [IIO_INCLI] = "incli",
  68         [IIO_ROT] = "rot",
  69         [IIO_ANGL] = "angl",
  70         [IIO_TIMESTAMP] = "timestamp",
  71         [IIO_CAPACITANCE] = "capacitance",
  72         [IIO_ALTVOLTAGE] = "altvoltage",
  73         [IIO_CCT] = "cct",
  74         [IIO_PRESSURE] = "pressure",
  75         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  76         [IIO_ACTIVITY] = "activity",
  77         [IIO_STEPS] = "steps",
  78         [IIO_ENERGY] = "energy",
  79         [IIO_DISTANCE] = "distance",
  80         [IIO_VELOCITY] = "velocity",
  81         [IIO_CONCENTRATION] = "concentration",
  82         [IIO_RESISTANCE] = "resistance",
  83         [IIO_PH] = "ph",
  84         [IIO_UVINDEX] = "uvindex",
  85         [IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  86         [IIO_COUNT] = "count",
  87         [IIO_INDEX] = "index",
  88         [IIO_GRAVITY]  = "gravity",
  89         [IIO_POSITIONRELATIVE]  = "positionrelative",
  90         [IIO_PHASE] = "phase",
  91         [IIO_MASSCONCENTRATION] = "massconcentration",
  92 };
  93
  94 static const char * const iio_modifier_names[] = {
  95         [IIO_MOD_X] = "x",
  96         [IIO_MOD_Y] = "y",
  97         [IIO_MOD_Z] = "z",
  98         [IIO_MOD_X_AND_Y] = "x&y",
  99         [IIO_MOD_X_AND_Z] = "x&z",
 100         [IIO_MOD_Y_AND_Z] = "y&z",
 101         [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
 102         [IIO_MOD_X_OR_Y] = "x|y",
 103         [IIO_MOD_X_OR_Z] = "x|z",
 104         [IIO_MOD_Y_OR_Z] = "y|z",
 105         [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 106         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 107         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 108         [IIO_MOD_LIGHT_BOTH] = "both",
 109         [IIO_MOD_LIGHT_IR] = "ir",
 110         [IIO_MOD_LIGHT_CLEAR] = "clear",
 111         [IIO_MOD_LIGHT_RED] = "red",
 112         [IIO_MOD_LIGHT_GREEN] = "green",
 113         [IIO_MOD_LIGHT_BLUE] = "blue",
 114         [IIO_MOD_LIGHT_UV] = "uv",
 115         [IIO_MOD_LIGHT_DUV] = "duv",
 116         [IIO_MOD_QUATERNION] = "quaternion",
 117         [IIO_MOD_TEMP_AMBIENT] = "ambient",
 118         [IIO_MOD_TEMP_OBJECT] = "object",
 119         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 120         [IIO_MOD_NORTH_TRUE] = "from_north_true",
 121         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 122         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 123         [IIO_MOD_RUNNING] = "running",
 124         [IIO_MOD_JOGGING] = "jogging",
 125         [IIO_MOD_WALKING] = "walking",
 126         [IIO_MOD_STILL] = "still",
 127         [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 128         [IIO_MOD_I] = "i",
 129         [IIO_MOD_Q] = "q",
 130         [IIO_MOD_CO2] = "co2",
 131         [IIO_MOD_VOC] = "voc",
 132         [IIO_MOD_PM1] = "pm1",
 133         [IIO_MOD_PM2P5] = "pm2p5",
 134         [IIO_MOD_PM4] = "pm4",
 135         [IIO_MOD_PM10] = "pm10",
 136 };
 137
 138 /* relies on pairs of these shared then separate */
 139 static const char * const iio_chan_info_postfix[] = {
 140         [IIO_CHAN_INFO_RAW] = "raw",
 141         [IIO_CHAN_INFO_PROCESSED] = "input",
 142         [IIO_CHAN_INFO_SCALE] = "scale",
 143         [IIO_CHAN_INFO_OFFSET] = "offset",
 144         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 145         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 146         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 147         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 148         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 149         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 150         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 151         = "filter_low_pass_3db_frequency",
 152         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 153         = "filter_high_pass_3db_frequency",
 154         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 155         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 156         [IIO_CHAN_INFO_PHASE] = "phase",
 157         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 158         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 159         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 160         [IIO_CHAN_INFO_ENABLE] = "en",
 161         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 162         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 163         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 164         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 165         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 166         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 167 };
 168
 169 /**
 170  * iio_find_channel_from_si() - get channel from its scan index
 171  * @indio_dev:          device
 172  * @si:                 scan index to match
 173  */
 174 const struct iio_chan_spec
 175 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 176 {
 177         int i;
 178
 179         for (i = 0; i < indio_dev->num_channels; i++)
 180                 if (indio_dev->channels[i].scan_index == si)
 181                         return &indio_dev->channels[i];
 182         return NULL;
 183 }
 184
 185 /* This turns up an awful lot */
 186 ssize_t iio_read_const_attr(struct device *dev,
 187                             struct device_attribute *attr,
 188                             char *buf)
 189 {
 190         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 191 }
 192 EXPORT_SYMBOL(iio_read_const_attr);
 193
 194 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 195 {
 196         int ret;
 197         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 198
 199         ret = mutex_lock_interruptible(&indio_dev->mlock);
 200         if (ret)
 201                 return ret;
 202         if ((ev_int && iio_event_enabled(ev_int)) ||
 203             iio_buffer_enabled(indio_dev)) {
 204                 mutex_unlock(&indio_dev->mlock);
 205                 return -EBUSY;
 206         }
 207         indio_dev->clock_id = clock_id;
 208         mutex_unlock(&indio_dev->mlock);
 209
 210         return 0;
 211 }
 212
 213 /**
 214  * iio_get_time_ns() - utility function to get a time stamp for events etc
 215  * @indio_dev: device
 216  */
 217 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 218 {
 219         struct timespec64 tp;
 220
 221         switch (iio_device_get_clock(indio_dev)) {
 222         case CLOCK_REALTIME:
 223                 return ktime_get_real_ns();
 224         case CLOCK_MONOTONIC:
 225                 return ktime_get_ns();
 226         case CLOCK_MONOTONIC_RAW:
 227                 return ktime_get_raw_ns();
 228         case CLOCK_REALTIME_COARSE:
 229                 return ktime_to_ns(ktime_get_coarse_real());
 230         case CLOCK_MONOTONIC_COARSE:
 231                 ktime_get_coarse_ts64(&tp);
 232                 return timespec64_to_ns(&tp);
 233         case CLOCK_BOOTTIME:
 234                 return ktime_get_boot_ns();
 235         case CLOCK_TAI:
 236                 return ktime_get_tai_ns();
 237         default:
 238                 BUG();
 239         }
 240 }
 241 EXPORT_SYMBOL(iio_get_time_ns);
 242
 243 /**
 244  * iio_get_time_res() - utility function to get time stamp clock resolution in
 245  *                      nano seconds.
 246  * @indio_dev: device
 247  */
 248 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 249 {
 250         switch (iio_device_get_clock(indio_dev)) {
 251         case CLOCK_REALTIME:
 252         case CLOCK_MONOTONIC:
 253         case CLOCK_MONOTONIC_RAW:
 254         case CLOCK_BOOTTIME:
 255         case CLOCK_TAI:
 256                 return hrtimer_resolution;
 257         case CLOCK_REALTIME_COARSE:
 258         case CLOCK_MONOTONIC_COARSE:
 259                 return LOW_RES_NSEC;
 260         default:
 261                 BUG();
 262         }
 263 }
 264 EXPORT_SYMBOL(iio_get_time_res);
 265
 266 static int __init iio_init(void)
 267 {
 268         int ret;
 269
 270         /* Register sysfs bus */
 271         ret  = bus_register(&iio_bus_type);
 272         if (ret < 0) {
 273                 pr_err("could not register bus type\n");
 274                 goto error_nothing;
 275         }
 276
 277         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 278         if (ret < 0) {
 279                 pr_err("failed to allocate char dev region\n");
 280                 goto error_unregister_bus_type;
 281         }
 282
 283         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 284
 285         return 0;
 286
 287 error_unregister_bus_type:
 288         bus_unregister(&iio_bus_type);
 289 error_nothing:
 290         return ret;
 291 }
 292
 293 static void __exit iio_exit(void)
 294 {
 295         if (iio_devt)
 296                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 297         bus_unregister(&iio_bus_type);
 298         debugfs_remove(iio_debugfs_dentry);
 299 }
 300
 301 #if defined(CONFIG_DEBUG_FS)
 302 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 303                               size_t count, loff_t *ppos)
 304 {
 305         struct iio_dev *indio_dev = file->private_data;
 306         char buf[20];
 307         unsigned val = 0;
 308         ssize_t len;
 309         int ret;
 310
 311         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 312                                                   indio_dev->cached_reg_addr,
 313                                                   0, &val);
 314         if (ret) {
 315                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 316                 return ret;
 317         }
 318
 319         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 320
 321         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 322 }
 323
 324 static ssize_t iio_debugfs_write_reg(struct file *file,
 325                      const char __user *userbuf, size_t count, loff_t *ppos)
 326 {
 327         struct iio_dev *indio_dev = file->private_data;
 328         unsigned reg, val;
 329         char buf[80];
 330         int ret;
 331
 332         count = min_t(size_t, count, (sizeof(buf)-1));
 333         if (copy_from_user(buf, userbuf, count))
 334                 return -EFAULT;
 335
 336         buf[count] = 0;
 337
 338         ret = sscanf(buf, "%i %i", &reg, &val);
 339
 340         switch (ret) {
 341         case 1:
 342                 indio_dev->cached_reg_addr = reg;
 343                 break;
 344         case 2:
 345                 indio_dev->cached_reg_addr = reg;
 346                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 347                                                           val, NULL);
 348                 if (ret) {
 349                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 350                                 __func__);
 351                         return ret;
 352                 }
 353                 break;
 354         default:
 355                 return -EINVAL;
 356         }
 357
 358         return count;
 359 }
 360
 361 static const struct file_operations iio_debugfs_reg_fops = {
 362         .open = simple_open,
 363         .read = iio_debugfs_read_reg,
 364         .write = iio_debugfs_write_reg,
 365 };
 366
 367 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 368 {
 369         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 370 }
 371
 372 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 373 {
 374         struct dentry *d;
 375
 376         if (indio_dev->info->debugfs_reg_access == NULL)
 377                 return 0;
 378
 379         if (!iio_debugfs_dentry)
 380                 return 0;
 381
 382         indio_dev->debugfs_dentry =
 383                 debugfs_create_dir(dev_name(&indio_dev->dev),
 384                                    iio_debugfs_dentry);
 385         if (indio_dev->debugfs_dentry == NULL) {
 386                 dev_warn(indio_dev->dev.parent,
 387                          "Failed to create debugfs directory\n");
 388                 return -EFAULT;
 389         }
 390
 391         d = debugfs_create_file("direct_reg_access", 0644,
 392                                 indio_dev->debugfs_dentry,
 393                                 indio_dev, &iio_debugfs_reg_fops);
 394         if (!d) {
 395                 iio_device_unregister_debugfs(indio_dev);
 396                 return -ENOMEM;
 397         }
 398
 399         return 0;
 400 }
 401 #else
 402 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 403 {
 404         return 0;
 405 }
 406
 407 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 408 {
 409 }
 410 #endif /* CONFIG_DEBUG_FS */
 411
 412 static ssize_t iio_read_channel_ext_info(struct device *dev,
 413                                      struct device_attribute *attr,
 414                                      char *buf)
 415 {
 416         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 417         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 418         const struct iio_chan_spec_ext_info *ext_info;
 419
 420         ext_info = &this_attr->c->ext_info[this_attr->address];
 421
 422         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 423 }
 424
 425 static ssize_t iio_write_channel_ext_info(struct device *dev,
 426                                      struct device_attribute *attr,
 427                                      const char *buf,
 428                                          size_t len)
 429 {
 430         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 431         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 432         const struct iio_chan_spec_ext_info *ext_info;
 433
 434         ext_info = &this_attr->c->ext_info[this_attr->address];
 435
 436         return ext_info->write(indio_dev, ext_info->private,
 437                                this_attr->c, buf, len);
 438 }
 439
 440 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 441         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 442 {
 443         const struct iio_enum *e = (const struct iio_enum *)priv;
 444         unsigned int i;
 445         size_t len = 0;
 446
 447         if (!e->num_items)
 448                 return 0;
 449
 450         for (i = 0; i < e->num_items; ++i)
 451                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 452
 453         /* replace last space with a newline */
 454         buf[len - 1] = '\n';
 455
 456         return len;
 457 }
 458 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 459
 460 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 461         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 462 {
 463         const struct iio_enum *e = (const struct iio_enum *)priv;
 464         int i;
 465
 466         if (!e->get)
 467                 return -EINVAL;
 468
 469         i = e->get(indio_dev, chan);
 470         if (i < 0)
 471                 return i;
 472         else if (i >= e->num_items)
 473                 return -EINVAL;
 474
 475         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 476 }
 477 EXPORT_SYMBOL_GPL(iio_enum_read);
 478
 479 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 480         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 481         size_t len)
 482 {
 483         const struct iio_enum *e = (const struct iio_enum *)priv;
 484         int ret;
 485
 486         if (!e->set)
 487                 return -EINVAL;
 488
 489         ret = __sysfs_match_string(e->items, e->num_items, buf);
 490         if (ret < 0)
 491                 return ret;
 492
 493         ret = e->set(indio_dev, chan, ret);
 494         return ret ? ret : len;
 495 }
 496 EXPORT_SYMBOL_GPL(iio_enum_write);
 497
 498 static const struct iio_mount_matrix iio_mount_idmatrix = {
 499         .rotation = {
 500                 "1", "0", "0",
 501                 "0", "1", "0",
 502                 "0", "0", "1"
 503         }
 504 };
 505
 506 static int iio_setup_mount_idmatrix(const struct device *dev,
 507                                     struct iio_mount_matrix *matrix)
 508 {
 509         *matrix = iio_mount_idmatrix;
 510         dev_info(dev, "mounting matrix not found: using identity...\n");
 511         return 0;
 512 }
 513
 514 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 515                               const struct iio_chan_spec *chan, char *buf)
 516 {
 517         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 518                                               priv)(indio_dev, chan);
 519
 520         if (IS_ERR(mtx))
 521                 return PTR_ERR(mtx);
 522
 523         if (!mtx)
 524                 mtx = &iio_mount_idmatrix;
 525
 526         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 527                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 528                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 529                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 530 }
 531 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 532
 533 /**
 534  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
 535  *                           device "mount-matrix" property
 536  * @dev:        device the mounting matrix property is assigned to
 537  * @propname:   device specific mounting matrix property name
 538  * @matrix:     where to store retrieved matrix
 539  *
 540  * If device is assigned no mounting matrix property, a default 3x3 identity
 541  * matrix will be filled in.
 542  *
 543  * Return: 0 if success, or a negative error code on failure.
 544  */
 545 int iio_read_mount_matrix(struct device *dev, const char *propname,
 546                           struct iio_mount_matrix *matrix)
 547 {
 548         size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
 549         int err;
 550
 551         err = device_property_read_string_array(dev, propname,
 552                                                 matrix->rotation, len);
 553         if (err == len)
 554                 return 0;
 555
 556         if (err >= 0)
 557                 /* Invalid number of matrix entries. */
 558                 return -EINVAL;
 559
 560         if (err != -EINVAL)
 561                 /* Invalid matrix declaration format. */
 562                 return err;
 563
 564         /* Matrix was not declared at all: fallback to identity. */
 565         return iio_setup_mount_idmatrix(dev, matrix);
 566 }
 567 EXPORT_SYMBOL(iio_read_mount_matrix);
 568
 569 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 570                                   int size, const int *vals)
 571 {
 572         unsigned long long tmp;
 573         int tmp0, tmp1;
 574         bool scale_db = false;
 575
 576         switch (type) {
 577         case IIO_VAL_INT:
 578                 return snprintf(buf, len, "%d", vals[0]);
 579         case IIO_VAL_INT_PLUS_MICRO_DB:
 580                 scale_db = true;
 581                 /* fall through */
 582         case IIO_VAL_INT_PLUS_MICRO:
 583                 if (vals[1] < 0)
 584                         return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 585                                         -vals[1], scale_db ? " dB" : "");
 586                 else
 587                         return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 588                                         scale_db ? " dB" : "");
 589         case IIO_VAL_INT_PLUS_NANO:
 590                 if (vals[1] < 0)
 591                         return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 592                                         -vals[1]);
 593                 else
 594                         return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 595         case IIO_VAL_FRACTIONAL:
 596                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 597                 tmp1 = vals[1];
 598                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 599                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 600         case IIO_VAL_FRACTIONAL_LOG2:
 601                 tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 602                 tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 603                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 604         case IIO_VAL_INT_MULTIPLE:
 605         {
 606                 int i;
 607                 int l = 0;
 608
 609                 for (i = 0; i < size; ++i) {
 610                         l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 611                         if (l >= len)
 612                                 break;
 613                 }
 614                 return l;
 615         }
 616         default:
 617                 return 0;
 618         }
 619 }
 620
 621 /**
 622  * iio_format_value() - Formats a IIO value into its string representation
 623  * @buf:        The buffer to which the formatted value gets written
 624  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 625  * @type:       One of the IIO_VAL_* constants. This decides how the val
 626  *              and val2 parameters are formatted.
 627  * @size:       Number of IIO value entries contained in vals
 628  * @vals:       Pointer to the values, exact meaning depends on the
 629  *              type parameter.
 630  *
 631  * Return: 0 by default, a negative number on failure or the
 632  *         total number of characters written for a type that belongs
 633  *         to the IIO_VAL_* constant.
 634  */
 635 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 636 {
 637         ssize_t len;
 638
 639         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 640         if (len >= PAGE_SIZE - 1)
 641                 return -EFBIG;
 642
 643         return len + sprintf(buf + len, "\n");
 644 }
 645 EXPORT_SYMBOL_GPL(iio_format_value);
 646
 647 static ssize_t iio_read_channel_info(struct device *dev,
 648                                      struct device_attribute *attr,
 649                                      char *buf)
 650 {
 651         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 652         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 653         int vals[INDIO_MAX_RAW_ELEMENTS];
 654         int ret;
 655         int val_len = 2;
 656
 657         if (indio_dev->info->read_raw_multi)
 658                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 659                                                         INDIO_MAX_RAW_ELEMENTS,
 660                                                         vals, &val_len,
 661                                                         this_attr->address);
 662         else
 663                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 664                                     &vals[0], &vals[1], this_attr->address);
 665
 666         if (ret < 0)
 667                 return ret;
 668
 669         return iio_format_value(buf, ret, val_len, vals);
 670 }
 671
 672 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 673                                      int type, int length)
 674 {
 675         int i;
 676         ssize_t len = 0;
 677
 678         switch (type) {
 679         case IIO_VAL_INT:
 680                 for (i = 0; i < length; i++) {
 681                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 682                                                   type, 1, &vals[i]);
 683                         if (len >= PAGE_SIZE)
 684                                 return -EFBIG;
 685                         if (i < length - 1)
 686                                 len += snprintf(buf + len, PAGE_SIZE - len,
 687                                                 " ");
 688                         else
 689                                 len += snprintf(buf + len, PAGE_SIZE - len,
 690                                                 "\n");
 691                         if (len >= PAGE_SIZE)
 692                                 return -EFBIG;
 693                 }
 694                 break;
 695         default:
 696                 for (i = 0; i < length / 2; i++) {
 697                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 698                                                   type, 2, &vals[i * 2]);
 699                         if (len >= PAGE_SIZE)
 700                                 return -EFBIG;
 701                         if (i < length / 2 - 1)
 702                                 len += snprintf(buf + len, PAGE_SIZE - len,
 703                                                 " ");
 704                         else
 705                                 len += snprintf(buf + len, PAGE_SIZE - len,
 706                                                 "\n");
 707                         if (len >= PAGE_SIZE)
 708                                 return -EFBIG;
 709                 }
 710         }
 711
 712         return len;
 713 }
 714
 715 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 716 {
 717         int i;
 718         ssize_t len;
 719
 720         len = snprintf(buf, PAGE_SIZE, "[");
 721         switch (type) {
 722         case IIO_VAL_INT:
 723                 for (i = 0; i < 3; i++) {
 724                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 725                                                   type, 1, &vals[i]);
 726                         if (len >= PAGE_SIZE)
 727                                 return -EFBIG;
 728                         if (i < 2)
 729                                 len += snprintf(buf + len, PAGE_SIZE - len,
 730                                                 " ");
 731                         else
 732                                 len += snprintf(buf + len, PAGE_SIZE - len,
 733                                                 "]\n");
 734                         if (len >= PAGE_SIZE)
 735                                 return -EFBIG;
 736                 }
 737                 break;
 738         default:
 739                 for (i = 0; i < 3; i++) {
 740                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 741                                                   type, 2, &vals[i * 2]);
 742                         if (len >= PAGE_SIZE)
 743                                 return -EFBIG;
 744                         if (i < 2)
 745                                 len += snprintf(buf + len, PAGE_SIZE - len,
 746                                                 " ");
 747                         else
 748                                 len += snprintf(buf + len, PAGE_SIZE - len,
 749                                                 "]\n");
 750                         if (len >= PAGE_SIZE)
 751                                 return -EFBIG;
 752                 }
 753         }
 754
 755         return len;
 756 }
 757
 758 static ssize_t iio_read_channel_info_avail(struct device *dev,
 759                                            struct device_attribute *attr,
 760                                            char *buf)
 761 {
 762         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 763         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 764         const int *vals;
 765         int ret;
 766         int length;
 767         int type;
 768
 769         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 770                                           &vals, &type, &length,
 771                                           this_attr->address);
 772
 773         if (ret < 0)
 774                 return ret;
 775         switch (ret) {
 776         case IIO_AVAIL_LIST:
 777                 return iio_format_avail_list(buf, vals, type, length);
 778         case IIO_AVAIL_RANGE:
 779                 return iio_format_avail_range(buf, vals, type);
 780         default:
 781                 return -EINVAL;
 782         }
 783 }
 784
 785 /**
 786  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 787  * @str: The string to parse
 788  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 789  * @integer: The integer part of the number
 790  * @fract: The fractional part of the number
 791  *
 792  * Returns 0 on success, or a negative error code if the string could not be
 793  * parsed.
 794  */
 795 int iio_str_to_fixpoint(const char *str, int fract_mult,
 796         int *integer, int *fract)
 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 (*str == '.' && integer_part) {
 828                         integer_part = false;
 829                 } else {
 830                         return -EINVAL;
 831                 }
 832                 str++;
 833         }
 834
 835         if (negative) {
 836                 if (i)
 837                         i = -i;
 838                 else
 839                         f = -f;
 840         }
 841
 842         *integer = i;
 843         *fract = f;
 844
 845         return 0;
 846 }
 847 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 848
 849 static ssize_t iio_write_channel_info(struct device *dev,
 850                                       struct device_attribute *attr,
 851                                       const char *buf,
 852                                       size_t len)
 853 {
 854         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 855         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 856         int ret, fract_mult = 100000;
 857         int integer, fract;
 858
 859         /* Assumes decimal - precision based on number of digits */
 860         if (!indio_dev->info->write_raw)
 861                 return -EINVAL;
 862
 863         if (indio_dev->info->write_raw_get_fmt)
 864                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 865                         this_attr->c, this_attr->address)) {
 866                 case IIO_VAL_INT:
 867                         fract_mult = 0;
 868                         break;
 869                 case IIO_VAL_INT_PLUS_MICRO:
 870                         fract_mult = 100000;
 871                         break;
 872                 case IIO_VAL_INT_PLUS_NANO:
 873                         fract_mult = 100000000;
 874                         break;
 875                 default:
 876                         return -EINVAL;
 877                 }
 878
 879         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 880         if (ret)
 881                 return ret;
 882
 883         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 884                                          integer, fract, this_attr->address);
 885         if (ret)
 886                 return ret;
 887
 888         return len;
 889 }
 890
 891 static
 892 int __iio_device_attr_init(struct device_attribute *dev_attr,
 893                            const char *postfix,
 894                            struct iio_chan_spec const *chan,
 895                            ssize_t (*readfunc)(struct device *dev,
 896                                                struct device_attribute *attr,
 897                                                char *buf),
 898                            ssize_t (*writefunc)(struct device *dev,
 899                                                 struct device_attribute *attr,
 900                                                 const char *buf,
 901                                                 size_t len),
 902                            enum iio_shared_by shared_by)
 903 {
 904         int ret = 0;
 905         char *name = NULL;
 906         char *full_postfix;
 907         sysfs_attr_init(&dev_attr->attr);
 908
 909         /* Build up postfix of <extend_name>_<modifier>_postfix */
 910         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 911                 if (chan->extend_name)
 912                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 913                                                  iio_modifier_names[chan
 914                                                                     ->channel2],
 915                                                  chan->extend_name,
 916                                                  postfix);
 917                 else
 918                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 919                                                  iio_modifier_names[chan
 920                                                                     ->channel2],
 921                                                  postfix);
 922         } else {
 923                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 924                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 925                 else
 926                         full_postfix = kasprintf(GFP_KERNEL,
 927                                                  "%s_%s",
 928                                                  chan->extend_name,
 929                                                  postfix);
 930         }
 931         if (full_postfix == NULL)
 932                 return -ENOMEM;
 933
 934         if (chan->differential) { /* Differential can not have modifier */
 935                 switch (shared_by) {
 936                 case IIO_SHARED_BY_ALL:
 937                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 938                         break;
 939                 case IIO_SHARED_BY_DIR:
 940                         name = kasprintf(GFP_KERNEL, "%s_%s",
 941                                                 iio_direction[chan->output],
 942                                                 full_postfix);
 943                         break;
 944                 case IIO_SHARED_BY_TYPE:
 945                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 946                                             iio_direction[chan->output],
 947                                             iio_chan_type_name_spec[chan->type],
 948                                             iio_chan_type_name_spec[chan->type],
 949                                             full_postfix);
 950                         break;
 951                 case IIO_SEPARATE:
 952                         if (!chan->indexed) {
 953                                 WARN(1, "Differential channels must be indexed\n");
 954                                 ret = -EINVAL;
 955                                 goto error_free_full_postfix;
 956                         }
 957                         name = kasprintf(GFP_KERNEL,
 958                                             "%s_%s%d-%s%d_%s",
 959                                             iio_direction[chan->output],
 960                                             iio_chan_type_name_spec[chan->type],
 961                                             chan->channel,
 962                                             iio_chan_type_name_spec[chan->type],
 963                                             chan->channel2,
 964                                             full_postfix);
 965                         break;
 966                 }
 967         } else { /* Single ended */
 968                 switch (shared_by) {
 969                 case IIO_SHARED_BY_ALL:
 970                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 971                         break;
 972                 case IIO_SHARED_BY_DIR:
 973                         name = kasprintf(GFP_KERNEL, "%s_%s",
 974                                                 iio_direction[chan->output],
 975                                                 full_postfix);
 976                         break;
 977                 case IIO_SHARED_BY_TYPE:
 978                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 979                                             iio_direction[chan->output],
 980                                             iio_chan_type_name_spec[chan->type],
 981                                             full_postfix);
 982                         break;
 983
 984                 case IIO_SEPARATE:
 985                         if (chan->indexed)
 986                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 987                                                     iio_direction[chan->output],
 988                                                     iio_chan_type_name_spec[chan->type],
 989                                                     chan->channel,
 990                                                     full_postfix);
 991                         else
 992                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 993                                                     iio_direction[chan->output],
 994                                                     iio_chan_type_name_spec[chan->type],
 995                                                     full_postfix);
 996                         break;
 997                 }
 998         }
 999         if (name == NULL) {
1000                 ret = -ENOMEM;
1001                 goto error_free_full_postfix;
1002         }
1003         dev_attr->attr.name = name;
1004
1005         if (readfunc) {
1006                 dev_attr->attr.mode |= S_IRUGO;
1007                 dev_attr->show = readfunc;
1008         }
1009
1010         if (writefunc) {
1011                 dev_attr->attr.mode |= S_IWUSR;
1012                 dev_attr->store = writefunc;
1013         }
1014
1015 error_free_full_postfix:
1016         kfree(full_postfix);
1017
1018         return ret;
1019 }
1020
1021 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1022 {
1023         kfree(dev_attr->attr.name);
1024 }
1025
1026 int __iio_add_chan_devattr(const char *postfix,
1027                            struct iio_chan_spec const *chan,
1028                            ssize_t (*readfunc)(struct device *dev,
1029                                                struct device_attribute *attr,
1030                                                char *buf),
1031                            ssize_t (*writefunc)(struct device *dev,
1032                                                 struct device_attribute *attr,
1033                                                 const char *buf,
1034                                                 size_t len),
1035                            u64 mask,
1036                            enum iio_shared_by shared_by,
1037                            struct device *dev,
1038                            struct list_head *attr_list)
1039 {
1040         int ret;
1041         struct iio_dev_attr *iio_attr, *t;
1042
1043         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1044         if (iio_attr == NULL)
1045                 return -ENOMEM;
1046         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1047                                      postfix, chan,
1048                                      readfunc, writefunc, shared_by);
1049         if (ret)
1050                 goto error_iio_dev_attr_free;
1051         iio_attr->c = chan;
1052         iio_attr->address = mask;
1053         list_for_each_entry(t, attr_list, l)
1054                 if (strcmp(t->dev_attr.attr.name,
1055                            iio_attr->dev_attr.attr.name) == 0) {
1056                         if (shared_by == IIO_SEPARATE)
1057                                 dev_err(dev, "tried to double register : %s\n",
1058                                         t->dev_attr.attr.name);
1059                         ret = -EBUSY;
1060                         goto error_device_attr_deinit;
1061                 }
1062         list_add(&iio_attr->l, attr_list);
1063
1064         return 0;
1065
1066 error_device_attr_deinit:
1067         __iio_device_attr_deinit(&iio_attr->dev_attr);
1068 error_iio_dev_attr_free:
1069         kfree(iio_attr);
1070         return ret;
1071 }
1072
1073 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1074                                          struct iio_chan_spec const *chan,
1075                                          enum iio_shared_by shared_by,
1076                                          const long *infomask)
1077 {
1078         int i, ret, attrcount = 0;
1079
1080         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1081                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1082                         return -EINVAL;
1083                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1084                                              chan,
1085                                              &iio_read_channel_info,
1086                                              &iio_write_channel_info,
1087                                              i,
1088                                              shared_by,
1089                                              &indio_dev->dev,
1090                                              &indio_dev->channel_attr_list);
1091                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1092                         continue;
1093                 else if (ret < 0)
1094                         return ret;
1095                 attrcount++;
1096         }
1097
1098         return attrcount;
1099 }
1100
1101 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1102                                                struct iio_chan_spec const *chan,
1103                                                enum iio_shared_by shared_by,
1104                                                const long *infomask)
1105 {
1106         int i, ret, attrcount = 0;
1107         char *avail_postfix;
1108
1109         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1110                 avail_postfix = kasprintf(GFP_KERNEL,
1111                                           "%s_available",
1112                                           iio_chan_info_postfix[i]);
1113                 if (!avail_postfix)
1114                         return -ENOMEM;
1115
1116                 ret = __iio_add_chan_devattr(avail_postfix,
1117                                              chan,
1118                                              &iio_read_channel_info_avail,
1119                                              NULL,
1120                                              i,
1121                                              shared_by,
1122                                              &indio_dev->dev,
1123                                              &indio_dev->channel_attr_list);
1124                 kfree(avail_postfix);
1125                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1126                         continue;
1127                 else if (ret < 0)
1128                         return ret;
1129                 attrcount++;
1130         }
1131
1132         return attrcount;
1133 }
1134
1135 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1136                                         struct iio_chan_spec const *chan)
1137 {
1138         int ret, attrcount = 0;
1139         const struct iio_chan_spec_ext_info *ext_info;
1140
1141         if (chan->channel < 0)
1142                 return 0;
1143         ret = iio_device_add_info_mask_type(indio_dev, chan,
1144                                             IIO_SEPARATE,
1145                                             &chan->info_mask_separate);
1146         if (ret < 0)
1147                 return ret;
1148         attrcount += ret;
1149
1150         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1151                                                   IIO_SEPARATE,
1152                                                   &chan->
1153                                                   info_mask_separate_available);
1154         if (ret < 0)
1155                 return ret;
1156         attrcount += ret;
1157
1158         ret = iio_device_add_info_mask_type(indio_dev, chan,
1159                                             IIO_SHARED_BY_TYPE,
1160                                             &chan->info_mask_shared_by_type);
1161         if (ret < 0)
1162                 return ret;
1163         attrcount += ret;
1164
1165         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1166                                                   IIO_SHARED_BY_TYPE,
1167                                                   &chan->
1168                                                   info_mask_shared_by_type_available);
1169         if (ret < 0)
1170                 return ret;
1171         attrcount += ret;
1172
1173         ret = iio_device_add_info_mask_type(indio_dev, chan,
1174                                             IIO_SHARED_BY_DIR,
1175                                             &chan->info_mask_shared_by_dir);
1176         if (ret < 0)
1177                 return ret;
1178         attrcount += ret;
1179
1180         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1181                                                   IIO_SHARED_BY_DIR,
1182                                                   &chan->info_mask_shared_by_dir_available);
1183         if (ret < 0)
1184                 return ret;
1185         attrcount += ret;
1186
1187         ret = iio_device_add_info_mask_type(indio_dev, chan,
1188                                             IIO_SHARED_BY_ALL,
1189                                             &chan->info_mask_shared_by_all);
1190         if (ret < 0)
1191                 return ret;
1192         attrcount += ret;
1193
1194         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1195                                                   IIO_SHARED_BY_ALL,
1196                                                   &chan->info_mask_shared_by_all_available);
1197         if (ret < 0)
1198                 return ret;
1199         attrcount += ret;
1200
1201         if (chan->ext_info) {
1202                 unsigned int i = 0;
1203                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1204                         ret = __iio_add_chan_devattr(ext_info->name,
1205                                         chan,
1206                                         ext_info->read ?
1207                                             &iio_read_channel_ext_info : NULL,
1208                                         ext_info->write ?
1209                                             &iio_write_channel_ext_info : NULL,
1210                                         i,
1211                                         ext_info->shared,
1212                                         &indio_dev->dev,
1213                                         &indio_dev->channel_attr_list);
1214                         i++;
1215                         if (ret == -EBUSY && ext_info->shared)
1216                                 continue;
1217
1218                         if (ret)
1219                                 return ret;
1220
1221                         attrcount++;
1222                 }
1223         }
1224
1225         return attrcount;
1226 }
1227
1228 /**
1229  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1230  * @attr_list: List of IIO device attributes
1231  *
1232  * This function frees the memory allocated for each of the IIO device
1233  * attributes in the list.
1234  */
1235 void iio_free_chan_devattr_list(struct list_head *attr_list)
1236 {
1237         struct iio_dev_attr *p, *n;
1238
1239         list_for_each_entry_safe(p, n, attr_list, l) {
1240                 kfree(p->dev_attr.attr.name);
1241                 list_del(&p->l);
1242                 kfree(p);
1243         }
1244 }
1245
1246 static ssize_t iio_show_dev_name(struct device *dev,
1247                                  struct device_attribute *attr,
1248                                  char *buf)
1249 {
1250         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1251         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1252 }
1253
1254 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1255
1256 static ssize_t iio_show_timestamp_clock(struct device *dev,
1257                                         struct device_attribute *attr,
1258                                         char *buf)
1259 {
1260         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1261         const clockid_t clk = iio_device_get_clock(indio_dev);
1262         const char *name;
1263         ssize_t sz;
1264
1265         switch (clk) {
1266         case CLOCK_REALTIME:
1267                 name = "realtime\n";
1268                 sz = sizeof("realtime\n");
1269                 break;
1270         case CLOCK_MONOTONIC:
1271                 name = "monotonic\n";
1272                 sz = sizeof("monotonic\n");
1273                 break;
1274         case CLOCK_MONOTONIC_RAW:
1275                 name = "monotonic_raw\n";
1276                 sz = sizeof("monotonic_raw\n");
1277                 break;
1278         case CLOCK_REALTIME_COARSE:
1279                 name = "realtime_coarse\n";
1280                 sz = sizeof("realtime_coarse\n");
1281                 break;
1282         case CLOCK_MONOTONIC_COARSE:
1283                 name = "monotonic_coarse\n";
1284                 sz = sizeof("monotonic_coarse\n");
1285                 break;
1286         case CLOCK_BOOTTIME:
1287                 name = "boottime\n";
1288                 sz = sizeof("boottime\n");
1289                 break;
1290         case CLOCK_TAI:
1291                 name = "tai\n";
1292                 sz = sizeof("tai\n");
1293                 break;
1294         default:
1295                 BUG();
1296         }
1297
1298         memcpy(buf, name, sz);
1299         return sz;
1300 }
1301
1302 static ssize_t iio_store_timestamp_clock(struct device *dev,
1303                                          struct device_attribute *attr,
1304                                          const char *buf, size_t len)
1305 {
1306         clockid_t clk;
1307         int ret;
1308
1309         if (sysfs_streq(buf, "realtime"))
1310                 clk = CLOCK_REALTIME;
1311         else if (sysfs_streq(buf, "monotonic"))
1312                 clk = CLOCK_MONOTONIC;
1313         else if (sysfs_streq(buf, "monotonic_raw"))
1314                 clk = CLOCK_MONOTONIC_RAW;
1315         else if (sysfs_streq(buf, "realtime_coarse"))
1316                 clk = CLOCK_REALTIME_COARSE;
1317         else if (sysfs_streq(buf, "monotonic_coarse"))
1318                 clk = CLOCK_MONOTONIC_COARSE;
1319         else if (sysfs_streq(buf, "boottime"))
1320                 clk = CLOCK_BOOTTIME;
1321         else if (sysfs_streq(buf, "tai"))
1322                 clk = CLOCK_TAI;
1323         else
1324                 return -EINVAL;
1325
1326         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1327         if (ret)
1328                 return ret;
1329
1330         return len;
1331 }
1332
1333 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1334                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1335
1336 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1337 {
1338         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1339         struct iio_dev_attr *p;
1340         struct attribute **attr, *clk = NULL;
1341
1342         /* First count elements in any existing group */
1343         if (indio_dev->info->attrs) {
1344                 attr = indio_dev->info->attrs->attrs;
1345                 while (*attr++ != NULL)
1346                         attrcount_orig++;
1347         }
1348         attrcount = attrcount_orig;
1349         /*
1350          * New channel registration method - relies on the fact a group does
1351          * not need to be initialized if its name is NULL.
1352          */
1353         if (indio_dev->channels)
1354                 for (i = 0; i < indio_dev->num_channels; i++) {
1355                         const struct iio_chan_spec *chan =
1356                                 &indio_dev->channels[i];
1357
1358                         if (chan->type == IIO_TIMESTAMP)
1359                                 clk = &dev_attr_current_timestamp_clock.attr;
1360
1361                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1362                         if (ret < 0)
1363                                 goto error_clear_attrs;
1364                         attrcount += ret;
1365                 }
1366
1367         if (indio_dev->event_interface)
1368                 clk = &dev_attr_current_timestamp_clock.attr;
1369
1370         if (indio_dev->name)
1371                 attrcount++;
1372         if (clk)
1373                 attrcount++;
1374
1375         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1376                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1377                                                    GFP_KERNEL);
1378         if (indio_dev->chan_attr_group.attrs == NULL) {
1379                 ret = -ENOMEM;
1380                 goto error_clear_attrs;
1381         }
1382         /* Copy across original attributes */
1383         if (indio_dev->info->attrs)
1384                 memcpy(indio_dev->chan_attr_group.attrs,
1385                        indio_dev->info->attrs->attrs,
1386                        sizeof(indio_dev->chan_attr_group.attrs[0])
1387                        *attrcount_orig);
1388         attrn = attrcount_orig;
1389         /* Add all elements from the list. */
1390         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1391                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1392         if (indio_dev->name)
1393                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1394         if (clk)
1395                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1396
1397         indio_dev->groups[indio_dev->groupcounter++] =
1398                 &indio_dev->chan_attr_group;
1399
1400         return 0;
1401
1402 error_clear_attrs:
1403         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1404
1405         return ret;
1406 }
1407
1408 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1409 {
1410
1411         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1412         kfree(indio_dev->chan_attr_group.attrs);
1413         indio_dev->chan_attr_group.attrs = NULL;
1414 }
1415
1416 static void iio_dev_release(struct device *device)
1417 {
1418         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1419         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1420                 iio_device_unregister_trigger_consumer(indio_dev);
1421         iio_device_unregister_eventset(indio_dev);
1422         iio_device_unregister_sysfs(indio_dev);
1423
1424         iio_buffer_put(indio_dev->buffer);
1425
1426         ida_simple_remove(&iio_ida, indio_dev->id);
1427         kfree(indio_dev);
1428 }
1429
1430 struct device_type iio_device_type = {
1431         .name = "iio_device",
1432         .release = iio_dev_release,
1433 };
1434
1435 /**
1436  * iio_device_alloc() - allocate an iio_dev from a driver
1437  * @sizeof_priv:        Space to allocate for private structure.
1438  **/
1439 struct iio_dev *iio_device_alloc(int sizeof_priv)
1440 {
1441         struct iio_dev *dev;
1442         size_t alloc_size;
1443
1444         alloc_size = sizeof(struct iio_dev);
1445         if (sizeof_priv) {
1446                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1447                 alloc_size += sizeof_priv;
1448         }
1449         /* ensure 32-byte alignment of whole construct ? */
1450         alloc_size += IIO_ALIGN - 1;
1451
1452         dev = kzalloc(alloc_size, GFP_KERNEL);
1453
1454         if (dev) {
1455                 dev->dev.groups = dev->groups;
1456                 dev->dev.type = &iio_device_type;
1457                 dev->dev.bus = &iio_bus_type;
1458                 device_initialize(&dev->dev);
1459                 dev_set_drvdata(&dev->dev, (void *)dev);
1460                 mutex_init(&dev->mlock);
1461                 mutex_init(&dev->info_exist_lock);
1462                 INIT_LIST_HEAD(&dev->channel_attr_list);
1463
1464                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1465                 if (dev->id < 0) {
1466                         /* cannot use a dev_err as the name isn't available */
1467                         pr_err("failed to get device id\n");
1468                         kfree(dev);
1469                         return NULL;
1470                 }
1471                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1472                 INIT_LIST_HEAD(&dev->buffer_list);
1473         }
1474
1475         return dev;
1476 }
1477 EXPORT_SYMBOL(iio_device_alloc);
1478
1479 /**
1480  * iio_device_free() - free an iio_dev from a driver
1481  * @dev:                the iio_dev associated with the device
1482  **/
1483 void iio_device_free(struct iio_dev *dev)
1484 {
1485         if (dev)
1486                 put_device(&dev->dev);
1487 }
1488 EXPORT_SYMBOL(iio_device_free);
1489
1490 static void devm_iio_device_release(struct device *dev, void *res)
1491 {
1492         iio_device_free(*(struct iio_dev **)res);
1493 }
1494
1495 int devm_iio_device_match(struct device *dev, void *res, void *data)
1496 {
1497         struct iio_dev **r = res;
1498         if (!r || !*r) {
1499                 WARN_ON(!r || !*r);
1500                 return 0;
1501         }
1502         return *r == data;
1503 }
1504 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1505
1506 /**
1507  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1508  * @dev:                Device to allocate iio_dev for
1509  * @sizeof_priv:        Space to allocate for private structure.
1510  *
1511  * Managed iio_device_alloc. iio_dev allocated with this function is
1512  * automatically freed on driver detach.
1513  *
1514  * If an iio_dev allocated with this function needs to be freed separately,
1515  * devm_iio_device_free() must be used.
1516  *
1517  * RETURNS:
1518  * Pointer to allocated iio_dev on success, NULL on failure.
1519  */
1520 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1521 {
1522         struct iio_dev **ptr, *iio_dev;
1523
1524         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1525                            GFP_KERNEL);
1526         if (!ptr)
1527                 return NULL;
1528
1529         iio_dev = iio_device_alloc(sizeof_priv);
1530         if (iio_dev) {
1531                 *ptr = iio_dev;
1532                 devres_add(dev, ptr);
1533         } else {
1534                 devres_free(ptr);
1535         }
1536
1537         return iio_dev;
1538 }
1539 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1540
1541 /**
1542  * devm_iio_device_free - Resource-managed iio_device_free()
1543  * @dev:                Device this iio_dev belongs to
1544  * @iio_dev:            the iio_dev associated with the device
1545  *
1546  * Free iio_dev allocated with devm_iio_device_alloc().
1547  */
1548 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1549 {
1550         int rc;
1551
1552         rc = devres_release(dev, devm_iio_device_release,
1553                             devm_iio_device_match, iio_dev);
1554         WARN_ON(rc);
1555 }
1556 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1557
1558 /**
1559  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1560  * @inode:      Inode structure for identifying the device in the file system
1561  * @filp:       File structure for iio device used to keep and later access
1562  *              private data
1563  *
1564  * Return: 0 on success or -EBUSY if the device is already opened
1565  **/
1566 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1567 {
1568         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1569                                                 struct iio_dev, chrdev);
1570
1571         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1572                 return -EBUSY;
1573
1574         iio_device_get(indio_dev);
1575
1576         filp->private_data = indio_dev;
1577
1578         return 0;
1579 }
1580
1581 /**
1582  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1583  * @inode:      Inode structure pointer for the char device
1584  * @filp:       File structure pointer for the char device
1585  *
1586  * Return: 0 for successful release
1587  */
1588 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1589 {
1590         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1591                                                 struct iio_dev, chrdev);
1592         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1593         iio_device_put(indio_dev);
1594
1595         return 0;
1596 }
1597
1598 /* Somewhat of a cross file organization violation - ioctls here are actually
1599  * event related */
1600 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1601 {
1602         struct iio_dev *indio_dev = filp->private_data;
1603         int __user *ip = (int __user *)arg;
1604         int fd;
1605
1606         if (!indio_dev->info)
1607                 return -ENODEV;
1608
1609         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1610                 fd = iio_event_getfd(indio_dev);
1611                 if (fd < 0)
1612                         return fd;
1613                 if (copy_to_user(ip, &fd, sizeof(fd)))
1614                         return -EFAULT;
1615                 return 0;
1616         }
1617         return -EINVAL;
1618 }
1619
1620 static const struct file_operations iio_buffer_fileops = {
1621         .read = iio_buffer_read_first_n_outer_addr,
1622         .release = iio_chrdev_release,
1623         .open = iio_chrdev_open,
1624         .poll = iio_buffer_poll_addr,
1625         .owner = THIS_MODULE,
1626         .llseek = noop_llseek,
1627         .unlocked_ioctl = iio_ioctl,
1628         .compat_ioctl = iio_ioctl,
1629 };
1630
1631 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1632 {
1633         int i, j;
1634         const struct iio_chan_spec *channels = indio_dev->channels;
1635
1636         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1637                 return 0;
1638
1639         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1640                 if (channels[i].scan_index < 0)
1641                         continue;
1642                 for (j = i + 1; j < indio_dev->num_channels; j++)
1643                         if (channels[i].scan_index == channels[j].scan_index) {
1644                                 dev_err(&indio_dev->dev,
1645                                         "Duplicate scan index %d\n",
1646                                         channels[i].scan_index);
1647                                 return -EINVAL;
1648                         }
1649         }
1650
1651         return 0;
1652 }
1653
1654 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1655
1656 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1657 {
1658         int ret;
1659
1660         indio_dev->driver_module = this_mod;
1661         /* If the calling driver did not initialize of_node, do it here */
1662         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1663                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1664
1665         ret = iio_check_unique_scan_index(indio_dev);
1666         if (ret < 0)
1667                 return ret;
1668
1669         if (!indio_dev->info)
1670                 return -EINVAL;
1671
1672         /* configure elements for the chrdev */
1673         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1674
1675         ret = iio_device_register_debugfs(indio_dev);
1676         if (ret) {
1677                 dev_err(indio_dev->dev.parent,
1678                         "Failed to register debugfs interfaces\n");
1679                 return ret;
1680         }
1681
1682         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1683         if (ret) {
1684                 dev_err(indio_dev->dev.parent,
1685                         "Failed to create buffer sysfs interfaces\n");
1686                 goto error_unreg_debugfs;
1687         }
1688
1689         ret = iio_device_register_sysfs(indio_dev);
1690         if (ret) {
1691                 dev_err(indio_dev->dev.parent,
1692                         "Failed to register sysfs interfaces\n");
1693                 goto error_buffer_free_sysfs;
1694         }
1695         ret = iio_device_register_eventset(indio_dev);
1696         if (ret) {
1697                 dev_err(indio_dev->dev.parent,
1698                         "Failed to register event set\n");
1699                 goto error_free_sysfs;
1700         }
1701         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1702                 iio_device_register_trigger_consumer(indio_dev);
1703
1704         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1705                 indio_dev->setup_ops == NULL)
1706                 indio_dev->setup_ops = &noop_ring_setup_ops;
1707
1708         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1709
1710         indio_dev->chrdev.owner = this_mod;
1711
1712         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1713         if (ret < 0)
1714                 goto error_unreg_eventset;
1715
1716         return 0;
1717
1718 error_unreg_eventset:
1719         iio_device_unregister_eventset(indio_dev);
1720 error_free_sysfs:
1721         iio_device_unregister_sysfs(indio_dev);
1722 error_buffer_free_sysfs:
1723         iio_buffer_free_sysfs_and_mask(indio_dev);
1724 error_unreg_debugfs:
1725         iio_device_unregister_debugfs(indio_dev);
1726         return ret;
1727 }
1728 EXPORT_SYMBOL(__iio_device_register);
1729
1730 /**
1731  * iio_device_unregister() - unregister a device from the IIO subsystem
1732  * @indio_dev:          Device structure representing the device.
1733  **/
1734 void iio_device_unregister(struct iio_dev *indio_dev)
1735 {
1736         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1737
1738         mutex_lock(&indio_dev->info_exist_lock);
1739
1740         iio_device_unregister_debugfs(indio_dev);
1741
1742         iio_disable_all_buffers(indio_dev);
1743
1744         indio_dev->info = NULL;
1745
1746         iio_device_wakeup_eventset(indio_dev);
1747         iio_buffer_wakeup_poll(indio_dev);
1748
1749         mutex_unlock(&indio_dev->info_exist_lock);
1750
1751         iio_buffer_free_sysfs_and_mask(indio_dev);
1752 }
1753 EXPORT_SYMBOL(iio_device_unregister);
1754
1755 static void devm_iio_device_unreg(struct device *dev, void *res)
1756 {
1757         iio_device_unregister(*(struct iio_dev **)res);
1758 }
1759
1760 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1761                                struct module *this_mod)
1762 {
1763         struct iio_dev **ptr;
1764         int ret;
1765
1766         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1767         if (!ptr)
1768                 return -ENOMEM;
1769
1770         *ptr = indio_dev;
1771         ret = __iio_device_register(indio_dev, this_mod);
1772         if (!ret)
1773                 devres_add(dev, ptr);
1774         else
1775                 devres_free(ptr);
1776
1777         return ret;
1778 }
1779 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1780
1781 /**
1782  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1783  * @dev:        Device this iio_dev belongs to
1784  * @indio_dev:  the iio_dev associated with the device
1785  *
1786  * Unregister iio_dev registered with devm_iio_device_register().
1787  */
1788 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1789 {
1790         int rc;
1791
1792         rc = devres_release(dev, devm_iio_device_unreg,
1793                             devm_iio_device_match, indio_dev);
1794         WARN_ON(rc);
1795 }
1796 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1797
1798 /**
1799  * iio_device_claim_direct_mode - Keep device in direct mode
1800  * @indio_dev:  the iio_dev associated with the device
1801  *
1802  * If the device is in direct mode it is guaranteed to stay
1803  * that way until iio_device_release_direct_mode() is called.
1804  *
1805  * Use with iio_device_release_direct_mode()
1806  *
1807  * Returns: 0 on success, -EBUSY on failure
1808  */
1809 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1810 {
1811         mutex_lock(&indio_dev->mlock);
1812
1813         if (iio_buffer_enabled(indio_dev)) {
1814                 mutex_unlock(&indio_dev->mlock);
1815                 return -EBUSY;
1816         }
1817         return 0;
1818 }
1819 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1820
1821 /**
1822  * iio_device_release_direct_mode - releases claim on direct mode
1823  * @indio_dev:  the iio_dev associated with the device
1824  *
1825  * Release the claim. Device is no longer guaranteed to stay
1826  * in direct mode.
1827  *
1828  * Use with iio_device_claim_direct_mode()
1829  */
1830 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1831 {
1832         mutex_unlock(&indio_dev->mlock);
1833 }
1834 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1835
1836 subsys_initcall(iio_init);
1837 module_exit(iio_exit);
1838
1839 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1840 MODULE_DESCRIPTION("Industrial I/O core");
1841 MODULE_LICENSE("GPL");