drivers/iio/industrialio-core.c

   1 /* The industrial I/O core
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * Based on elements of hwmon and input subsystems.
  10  */
  11
  12 #define pr_fmt(fmt) "iio-core: " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/idr.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19 #include <linux/device.h>
  20 #include <linux/fs.h>
  21 #include <linux/poll.h>
  22 #include <linux/sched.h>
  23 #include <linux/wait.h>
  24 #include <linux/cdev.h>
  25 #include <linux/slab.h>
  26 #include <linux/anon_inodes.h>
  27 #include <linux/debugfs.h>
  28 #include <linux/mutex.h>
  29 #include <linux/iio/iio.h>
  30 #include "iio_core.h"
  31 #include "iio_core_trigger.h"
  32 #include <linux/iio/sysfs.h>
  33 #include <linux/iio/events.h>
  34 #include <linux/iio/buffer.h>
  35 #include <linux/iio/buffer_impl.h>
  36
  37 /* IDA to assign each registered device a unique id */
  38 static DEFINE_IDA(iio_ida);
  39
  40 static dev_t iio_devt;
  41
  42 #define IIO_DEV_MAX 256
  43 struct bus_type iio_bus_type = {
  44         .name = "iio",
  45 };
  46 EXPORT_SYMBOL(iio_bus_type);
  47
  48 static struct dentry *iio_debugfs_dentry;
  49
  50 static const char * const iio_direction[] = {
  51         [0] = "in",
  52         [1] = "out",
  53 };
  54
  55 static const char * const iio_chan_type_name_spec[] = {
  56         [IIO_VOLTAGE] = "voltage",
  57         [IIO_CURRENT] = "current",
  58         [IIO_POWER] = "power",
  59         [IIO_ACCEL] = "accel",
  60         [IIO_ANGL_VEL] = "anglvel",
  61         [IIO_MAGN] = "magn",
  62         [IIO_LIGHT] = "illuminance",
  63         [IIO_INTENSITY] = "intensity",
  64         [IIO_PROXIMITY] = "proximity",
  65         [IIO_TEMP] = "temp",
  66         [IIO_INCLI] = "incli",
  67         [IIO_ROT] = "rot",
  68         [IIO_ANGL] = "angl",
  69         [IIO_TIMESTAMP] = "timestamp",
  70         [IIO_CAPACITANCE] = "capacitance",
  71         [IIO_ALTVOLTAGE] = "altvoltage",
  72         [IIO_CCT] = "cct",
  73         [IIO_PRESSURE] = "pressure",
  74         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  75         [IIO_ACTIVITY] = "activity",
  76         [IIO_STEPS] = "steps",
  77         [IIO_ENERGY] = "energy",
  78         [IIO_DISTANCE] = "distance",
  79         [IIO_VELOCITY] = "velocity",
  80         [IIO_CONCENTRATION] = "concentration",
  81         [IIO_RESISTANCE] = "resistance",
  82         [IIO_PH] = "ph",
  83         [IIO_UVINDEX] = "uvindex",
  84         [IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  85         [IIO_COUNT] = "count",
  86         [IIO_INDEX] = "index",
  87         [IIO_GRAVITY]  = "gravity",
  88 };
  89
  90 static const char * const iio_modifier_names[] = {
  91         [IIO_MOD_X] = "x",
  92         [IIO_MOD_Y] = "y",
  93         [IIO_MOD_Z] = "z",
  94         [IIO_MOD_X_AND_Y] = "x&y",
  95         [IIO_MOD_X_AND_Z] = "x&z",
  96         [IIO_MOD_Y_AND_Z] = "y&z",
  97         [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
  98         [IIO_MOD_X_OR_Y] = "x|y",
  99         [IIO_MOD_X_OR_Z] = "x|z",
 100         [IIO_MOD_Y_OR_Z] = "y|z",
 101         [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 102         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 103         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 104         [IIO_MOD_LIGHT_BOTH] = "both",
 105         [IIO_MOD_LIGHT_IR] = "ir",
 106         [IIO_MOD_LIGHT_CLEAR] = "clear",
 107         [IIO_MOD_LIGHT_RED] = "red",
 108         [IIO_MOD_LIGHT_GREEN] = "green",
 109         [IIO_MOD_LIGHT_BLUE] = "blue",
 110         [IIO_MOD_LIGHT_UV] = "uv",
 111         [IIO_MOD_QUATERNION] = "quaternion",
 112         [IIO_MOD_TEMP_AMBIENT] = "ambient",
 113         [IIO_MOD_TEMP_OBJECT] = "object",
 114         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 115         [IIO_MOD_NORTH_TRUE] = "from_north_true",
 116         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 117         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 118         [IIO_MOD_RUNNING] = "running",
 119         [IIO_MOD_JOGGING] = "jogging",
 120         [IIO_MOD_WALKING] = "walking",
 121         [IIO_MOD_STILL] = "still",
 122         [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 123         [IIO_MOD_I] = "i",
 124         [IIO_MOD_Q] = "q",
 125         [IIO_MOD_CO2] = "co2",
 126         [IIO_MOD_VOC] = "voc",
 127 };
 128
 129 /* relies on pairs of these shared then separate */
 130 static const char * const iio_chan_info_postfix[] = {
 131         [IIO_CHAN_INFO_RAW] = "raw",
 132         [IIO_CHAN_INFO_PROCESSED] = "input",
 133         [IIO_CHAN_INFO_SCALE] = "scale",
 134         [IIO_CHAN_INFO_OFFSET] = "offset",
 135         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 136         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 137         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 138         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 139         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 140         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 141         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 142         = "filter_low_pass_3db_frequency",
 143         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 144         = "filter_high_pass_3db_frequency",
 145         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 146         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 147         [IIO_CHAN_INFO_PHASE] = "phase",
 148         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 149         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 150         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 151         [IIO_CHAN_INFO_ENABLE] = "en",
 152         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 153         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 154         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 155         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 156         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 157         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 158 };
 159
 160 /**
 161  * iio_find_channel_from_si() - get channel from its scan index
 162  * @indio_dev:          device
 163  * @si:                 scan index to match
 164  */
 165 const struct iio_chan_spec
 166 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 167 {
 168         int i;
 169
 170         for (i = 0; i < indio_dev->num_channels; i++)
 171                 if (indio_dev->channels[i].scan_index == si)
 172                         return &indio_dev->channels[i];
 173         return NULL;
 174 }
 175
 176 /* This turns up an awful lot */
 177 ssize_t iio_read_const_attr(struct device *dev,
 178                             struct device_attribute *attr,
 179                             char *buf)
 180 {
 181         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 182 }
 183 EXPORT_SYMBOL(iio_read_const_attr);
 184
 185 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 186 {
 187         int ret;
 188         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 189
 190         ret = mutex_lock_interruptible(&indio_dev->mlock);
 191         if (ret)
 192                 return ret;
 193         if ((ev_int && iio_event_enabled(ev_int)) ||
 194             iio_buffer_enabled(indio_dev)) {
 195                 mutex_unlock(&indio_dev->mlock);
 196                 return -EBUSY;
 197         }
 198         indio_dev->clock_id = clock_id;
 199         mutex_unlock(&indio_dev->mlock);
 200
 201         return 0;
 202 }
 203
 204 /**
 205  * iio_get_time_ns() - utility function to get a time stamp for events etc
 206  * @indio_dev: device
 207  */
 208 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 209 {
 210         struct timespec tp;
 211
 212         switch (iio_device_get_clock(indio_dev)) {
 213         case CLOCK_REALTIME:
 214                 ktime_get_real_ts(&tp);
 215                 break;
 216         case CLOCK_MONOTONIC:
 217                 ktime_get_ts(&tp);
 218                 break;
 219         case CLOCK_MONOTONIC_RAW:
 220                 getrawmonotonic(&tp);
 221                 break;
 222         case CLOCK_REALTIME_COARSE:
 223                 tp = current_kernel_time();
 224                 break;
 225         case CLOCK_MONOTONIC_COARSE:
 226                 tp = get_monotonic_coarse();
 227                 break;
 228         case CLOCK_BOOTTIME:
 229                 get_monotonic_boottime(&tp);
 230                 break;
 231         case CLOCK_TAI:
 232                 timekeeping_clocktai(&tp);
 233                 break;
 234         default:
 235                 BUG();
 236         }
 237
 238         return timespec_to_ns(&tp);
 239 }
 240 EXPORT_SYMBOL(iio_get_time_ns);
 241
 242 /**
 243  * iio_get_time_res() - utility function to get time stamp clock resolution in
 244  *                      nano seconds.
 245  * @indio_dev: device
 246  */
 247 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 248 {
 249         switch (iio_device_get_clock(indio_dev)) {
 250         case CLOCK_REALTIME:
 251         case CLOCK_MONOTONIC:
 252         case CLOCK_MONOTONIC_RAW:
 253         case CLOCK_BOOTTIME:
 254         case CLOCK_TAI:
 255                 return hrtimer_resolution;
 256         case CLOCK_REALTIME_COARSE:
 257         case CLOCK_MONOTONIC_COARSE:
 258                 return LOW_RES_NSEC;
 259         default:
 260                 BUG();
 261         }
 262 }
 263 EXPORT_SYMBOL(iio_get_time_res);
 264
 265 static int __init iio_init(void)
 266 {
 267         int ret;
 268
 269         /* Register sysfs bus */
 270         ret  = bus_register(&iio_bus_type);
 271         if (ret < 0) {
 272                 pr_err("could not register bus type\n");
 273                 goto error_nothing;
 274         }
 275
 276         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 277         if (ret < 0) {
 278                 pr_err("failed to allocate char dev region\n");
 279                 goto error_unregister_bus_type;
 280         }
 281
 282         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 283
 284         return 0;
 285
 286 error_unregister_bus_type:
 287         bus_unregister(&iio_bus_type);
 288 error_nothing:
 289         return ret;
 290 }
 291
 292 static void __exit iio_exit(void)
 293 {
 294         if (iio_devt)
 295                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 296         bus_unregister(&iio_bus_type);
 297         debugfs_remove(iio_debugfs_dentry);
 298 }
 299
 300 #if defined(CONFIG_DEBUG_FS)
 301 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 302                               size_t count, loff_t *ppos)
 303 {
 304         struct iio_dev *indio_dev = file->private_data;
 305         char buf[20];
 306         unsigned val = 0;
 307         ssize_t len;
 308         int ret;
 309
 310         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 311                                                   indio_dev->cached_reg_addr,
 312                                                   0, &val);
 313         if (ret) {
 314                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 315                 return ret;
 316         }
 317
 318         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 319
 320         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 321 }
 322
 323 static ssize_t iio_debugfs_write_reg(struct file *file,
 324                      const char __user *userbuf, size_t count, loff_t *ppos)
 325 {
 326         struct iio_dev *indio_dev = file->private_data;
 327         unsigned reg, val;
 328         char buf[80];
 329         int ret;
 330
 331         count = min_t(size_t, count, (sizeof(buf)-1));
 332         if (copy_from_user(buf, userbuf, count))
 333                 return -EFAULT;
 334
 335         buf[count] = 0;
 336
 337         ret = sscanf(buf, "%i %i", &reg, &val);
 338
 339         switch (ret) {
 340         case 1:
 341                 indio_dev->cached_reg_addr = reg;
 342                 break;
 343         case 2:
 344                 indio_dev->cached_reg_addr = reg;
 345                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 346                                                           val, NULL);
 347                 if (ret) {
 348                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 349                                 __func__);
 350                         return ret;
 351                 }
 352                 break;
 353         default:
 354                 return -EINVAL;
 355         }
 356
 357         return count;
 358 }
 359
 360 static const struct file_operations iio_debugfs_reg_fops = {
 361         .open = simple_open,
 362         .read = iio_debugfs_read_reg,
 363         .write = iio_debugfs_write_reg,
 364 };
 365
 366 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 367 {
 368         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 369 }
 370
 371 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 372 {
 373         struct dentry *d;
 374
 375         if (indio_dev->info->debugfs_reg_access == NULL)
 376                 return 0;
 377
 378         if (!iio_debugfs_dentry)
 379                 return 0;
 380
 381         indio_dev->debugfs_dentry =
 382                 debugfs_create_dir(dev_name(&indio_dev->dev),
 383                                    iio_debugfs_dentry);
 384         if (indio_dev->debugfs_dentry == NULL) {
 385                 dev_warn(indio_dev->dev.parent,
 386                          "Failed to create debugfs directory\n");
 387                 return -EFAULT;
 388         }
 389
 390         d = debugfs_create_file("direct_reg_access", 0644,
 391                                 indio_dev->debugfs_dentry,
 392                                 indio_dev, &iio_debugfs_reg_fops);
 393         if (!d) {
 394                 iio_device_unregister_debugfs(indio_dev);
 395                 return -ENOMEM;
 396         }
 397
 398         return 0;
 399 }
 400 #else
 401 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 402 {
 403         return 0;
 404 }
 405
 406 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 407 {
 408 }
 409 #endif /* CONFIG_DEBUG_FS */
 410
 411 static ssize_t iio_read_channel_ext_info(struct device *dev,
 412                                      struct device_attribute *attr,
 413                                      char *buf)
 414 {
 415         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 416         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 417         const struct iio_chan_spec_ext_info *ext_info;
 418
 419         ext_info = &this_attr->c->ext_info[this_attr->address];
 420
 421         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 422 }
 423
 424 static ssize_t iio_write_channel_ext_info(struct device *dev,
 425                                      struct device_attribute *attr,
 426                                      const char *buf,
 427                                          size_t len)
 428 {
 429         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 430         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 431         const struct iio_chan_spec_ext_info *ext_info;
 432
 433         ext_info = &this_attr->c->ext_info[this_attr->address];
 434
 435         return ext_info->write(indio_dev, ext_info->private,
 436                                this_attr->c, buf, len);
 437 }
 438
 439 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 440         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 441 {
 442         const struct iio_enum *e = (const struct iio_enum *)priv;
 443         unsigned int i;
 444         size_t len = 0;
 445
 446         if (!e->num_items)
 447                 return 0;
 448
 449         for (i = 0; i < e->num_items; ++i)
 450                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 451
 452         /* replace last space with a newline */
 453         buf[len - 1] = '\n';
 454
 455         return len;
 456 }
 457 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 458
 459 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 460         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 461 {
 462         const struct iio_enum *e = (const struct iio_enum *)priv;
 463         int i;
 464
 465         if (!e->get)
 466                 return -EINVAL;
 467
 468         i = e->get(indio_dev, chan);
 469         if (i < 0)
 470                 return i;
 471         else if (i >= e->num_items)
 472                 return -EINVAL;
 473
 474         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 475 }
 476 EXPORT_SYMBOL_GPL(iio_enum_read);
 477
 478 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 479         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 480         size_t len)
 481 {
 482         const struct iio_enum *e = (const struct iio_enum *)priv;
 483         int ret;
 484
 485         if (!e->set)
 486                 return -EINVAL;
 487
 488         ret = __sysfs_match_string(e->items, e->num_items, buf);
 489         if (ret < 0)
 490                 return ret;
 491
 492         ret = e->set(indio_dev, chan, ret);
 493         return ret ? ret : len;
 494 }
 495 EXPORT_SYMBOL_GPL(iio_enum_write);
 496
 497 static const struct iio_mount_matrix iio_mount_idmatrix = {
 498         .rotation = {
 499                 "1", "0", "0",
 500                 "0", "1", "0",
 501                 "0", "0", "1"
 502         }
 503 };
 504
 505 static int iio_setup_mount_idmatrix(const struct device *dev,
 506                                     struct iio_mount_matrix *matrix)
 507 {
 508         *matrix = iio_mount_idmatrix;
 509         dev_info(dev, "mounting matrix not found: using identity...\n");
 510         return 0;
 511 }
 512
 513 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 514                               const struct iio_chan_spec *chan, char *buf)
 515 {
 516         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 517                                               priv)(indio_dev, chan);
 518
 519         if (IS_ERR(mtx))
 520                 return PTR_ERR(mtx);
 521
 522         if (!mtx)
 523                 mtx = &iio_mount_idmatrix;
 524
 525         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 526                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 527                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 528                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 529 }
 530 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 531
 532 /**
 533  * of_iio_read_mount_matrix() - retrieve iio device mounting matrix from
 534  *                              device-tree "mount-matrix" property
 535  * @dev:        device the mounting matrix property is assigned to
 536  * @propname:   device specific mounting matrix property name
 537  * @matrix:     where to store retrieved matrix
 538  *
 539  * If device is assigned no mounting matrix property, a default 3x3 identity
 540  * matrix will be filled in.
 541  *
 542  * Return: 0 if success, or a negative error code on failure.
 543  */
 544 #ifdef CONFIG_OF
 545 int of_iio_read_mount_matrix(const struct device *dev,
 546                              const char *propname,
 547                              struct iio_mount_matrix *matrix)
 548 {
 549         if (dev->of_node) {
 550                 int err = of_property_read_string_array(dev->of_node,
 551                                 propname, matrix->rotation,
 552                                 ARRAY_SIZE(iio_mount_idmatrix.rotation));
 553
 554                 if (err == ARRAY_SIZE(iio_mount_idmatrix.rotation))
 555                         return 0;
 556
 557                 if (err >= 0)
 558                         /* Invalid number of matrix entries. */
 559                         return -EINVAL;
 560
 561                 if (err != -EINVAL)
 562                         /* Invalid matrix declaration format. */
 563                         return err;
 564         }
 565
 566         /* Matrix was not declared at all: fallback to identity. */
 567         return iio_setup_mount_idmatrix(dev, matrix);
 568 }
 569 #else
 570 int of_iio_read_mount_matrix(const struct device *dev,
 571                              const char *propname,
 572                              struct iio_mount_matrix *matrix)
 573 {
 574         return iio_setup_mount_idmatrix(dev, matrix);
 575 }
 576 #endif
 577 EXPORT_SYMBOL(of_iio_read_mount_matrix);
 578
 579 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 580                                   int size, const int *vals)
 581 {
 582         unsigned long long tmp;
 583         int tmp0, tmp1;
 584         bool scale_db = false;
 585
 586         switch (type) {
 587         case IIO_VAL_INT:
 588                 return snprintf(buf, len, "%d", vals[0]);
 589         case IIO_VAL_INT_PLUS_MICRO_DB:
 590                 scale_db = true;
 591         case IIO_VAL_INT_PLUS_MICRO:
 592                 if (vals[1] < 0)
 593                         return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 594                                         -vals[1], scale_db ? " dB" : "");
 595                 else
 596                         return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 597                                         scale_db ? " dB" : "");
 598         case IIO_VAL_INT_PLUS_NANO:
 599                 if (vals[1] < 0)
 600                         return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 601                                         -vals[1]);
 602                 else
 603                         return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 604         case IIO_VAL_FRACTIONAL:
 605                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 606                 tmp1 = vals[1];
 607                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 608                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 609         case IIO_VAL_FRACTIONAL_LOG2:
 610                 tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 611                 tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 612                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 613         case IIO_VAL_INT_MULTIPLE:
 614         {
 615                 int i;
 616                 int l = 0;
 617
 618                 for (i = 0; i < size; ++i) {
 619                         l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 620                         if (l >= len)
 621                                 break;
 622                 }
 623                 return l;
 624         }
 625         default:
 626                 return 0;
 627         }
 628 }
 629
 630 /**
 631  * iio_format_value() - Formats a IIO value into its string representation
 632  * @buf:        The buffer to which the formatted value gets written
 633  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 634  * @type:       One of the IIO_VAL_... constants. This decides how the val
 635  *              and val2 parameters are formatted.
 636  * @size:       Number of IIO value entries contained in vals
 637  * @vals:       Pointer to the values, exact meaning depends on the
 638  *              type parameter.
 639  *
 640  * Return: 0 by default, a negative number on failure or the
 641  *         total number of characters written for a type that belongs
 642  *         to the IIO_VAL_... constant.
 643  */
 644 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 645 {
 646         ssize_t len;
 647
 648         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 649         if (len >= PAGE_SIZE - 1)
 650                 return -EFBIG;
 651
 652         return len + sprintf(buf + len, "\n");
 653 }
 654 EXPORT_SYMBOL_GPL(iio_format_value);
 655
 656 static ssize_t iio_read_channel_info(struct device *dev,
 657                                      struct device_attribute *attr,
 658                                      char *buf)
 659 {
 660         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 661         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 662         int vals[INDIO_MAX_RAW_ELEMENTS];
 663         int ret;
 664         int val_len = 2;
 665
 666         if (indio_dev->info->read_raw_multi)
 667                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 668                                                         INDIO_MAX_RAW_ELEMENTS,
 669                                                         vals, &val_len,
 670                                                         this_attr->address);
 671         else
 672                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 673                                     &vals[0], &vals[1], this_attr->address);
 674
 675         if (ret < 0)
 676                 return ret;
 677
 678         return iio_format_value(buf, ret, val_len, vals);
 679 }
 680
 681 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 682                                      int type, int length)
 683 {
 684         int i;
 685         ssize_t len = 0;
 686
 687         switch (type) {
 688         case IIO_VAL_INT:
 689                 for (i = 0; i < length; i++) {
 690                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 691                                                   type, 1, &vals[i]);
 692                         if (len >= PAGE_SIZE)
 693                                 return -EFBIG;
 694                         if (i < length - 1)
 695                                 len += snprintf(buf + len, PAGE_SIZE - len,
 696                                                 " ");
 697                         else
 698                                 len += snprintf(buf + len, PAGE_SIZE - len,
 699                                                 "\n");
 700                         if (len >= PAGE_SIZE)
 701                                 return -EFBIG;
 702                 }
 703                 break;
 704         default:
 705                 for (i = 0; i < length / 2; i++) {
 706                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 707                                                   type, 2, &vals[i * 2]);
 708                         if (len >= PAGE_SIZE)
 709                                 return -EFBIG;
 710                         if (i < length / 2 - 1)
 711                                 len += snprintf(buf + len, PAGE_SIZE - len,
 712                                                 " ");
 713                         else
 714                                 len += snprintf(buf + len, PAGE_SIZE - len,
 715                                                 "\n");
 716                         if (len >= PAGE_SIZE)
 717                                 return -EFBIG;
 718                 }
 719         }
 720
 721         return len;
 722 }
 723
 724 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 725 {
 726         int i;
 727         ssize_t len;
 728
 729         len = snprintf(buf, PAGE_SIZE, "[");
 730         switch (type) {
 731         case IIO_VAL_INT:
 732                 for (i = 0; i < 3; i++) {
 733                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 734                                                   type, 1, &vals[i]);
 735                         if (len >= PAGE_SIZE)
 736                                 return -EFBIG;
 737                         if (i < 2)
 738                                 len += snprintf(buf + len, PAGE_SIZE - len,
 739                                                 " ");
 740                         else
 741                                 len += snprintf(buf + len, PAGE_SIZE - len,
 742                                                 "]\n");
 743                         if (len >= PAGE_SIZE)
 744                                 return -EFBIG;
 745                 }
 746                 break;
 747         default:
 748                 for (i = 0; i < 3; i++) {
 749                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 750                                                   type, 2, &vals[i * 2]);
 751                         if (len >= PAGE_SIZE)
 752                                 return -EFBIG;
 753                         if (i < 2)
 754                                 len += snprintf(buf + len, PAGE_SIZE - len,
 755                                                 " ");
 756                         else
 757                                 len += snprintf(buf + len, PAGE_SIZE - len,
 758                                                 "]\n");
 759                         if (len >= PAGE_SIZE)
 760                                 return -EFBIG;
 761                 }
 762         }
 763
 764         return len;
 765 }
 766
 767 static ssize_t iio_read_channel_info_avail(struct device *dev,
 768                                            struct device_attribute *attr,
 769                                            char *buf)
 770 {
 771         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 772         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 773         const int *vals;
 774         int ret;
 775         int length;
 776         int type;
 777
 778         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 779                                           &vals, &type, &length,
 780                                           this_attr->address);
 781
 782         if (ret < 0)
 783                 return ret;
 784         switch (ret) {
 785         case IIO_AVAIL_LIST:
 786                 return iio_format_avail_list(buf, vals, type, length);
 787         case IIO_AVAIL_RANGE:
 788                 return iio_format_avail_range(buf, vals, type);
 789         default:
 790                 return -EINVAL;
 791         }
 792 }
 793
 794 /**
 795  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 796  * @str: The string to parse
 797  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 798  * @integer: The integer part of the number
 799  * @fract: The fractional part of the number
 800  *
 801  * Returns 0 on success, or a negative error code if the string could not be
 802  * parsed.
 803  */
 804 int iio_str_to_fixpoint(const char *str, int fract_mult,
 805         int *integer, int *fract)
 806 {
 807         int i = 0, f = 0;
 808         bool integer_part = true, negative = false;
 809
 810         if (fract_mult == 0) {
 811                 *fract = 0;
 812
 813                 return kstrtoint(str, 0, integer);
 814         }
 815
 816         if (str[0] == '-') {
 817                 negative = true;
 818                 str++;
 819         } else if (str[0] == '+') {
 820                 str++;
 821         }
 822
 823         while (*str) {
 824                 if ('0' <= *str && *str <= '9') {
 825                         if (integer_part) {
 826                                 i = i * 10 + *str - '0';
 827                         } else {
 828                                 f += fract_mult * (*str - '0');
 829                                 fract_mult /= 10;
 830                         }
 831                 } else if (*str == '\n') {
 832                         if (*(str + 1) == '\0')
 833                                 break;
 834                         else
 835                                 return -EINVAL;
 836                 } else if (*str == '.' && integer_part) {
 837                         integer_part = false;
 838                 } else {
 839                         return -EINVAL;
 840                 }
 841                 str++;
 842         }
 843
 844         if (negative) {
 845                 if (i)
 846                         i = -i;
 847                 else
 848                         f = -f;
 849         }
 850
 851         *integer = i;
 852         *fract = f;
 853
 854         return 0;
 855 }
 856 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 857
 858 static ssize_t iio_write_channel_info(struct device *dev,
 859                                       struct device_attribute *attr,
 860                                       const char *buf,
 861                                       size_t len)
 862 {
 863         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 864         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 865         int ret, fract_mult = 100000;
 866         int integer, fract;
 867
 868         /* Assumes decimal - precision based on number of digits */
 869         if (!indio_dev->info->write_raw)
 870                 return -EINVAL;
 871
 872         if (indio_dev->info->write_raw_get_fmt)
 873                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 874                         this_attr->c, this_attr->address)) {
 875                 case IIO_VAL_INT:
 876                         fract_mult = 0;
 877                         break;
 878                 case IIO_VAL_INT_PLUS_MICRO:
 879                         fract_mult = 100000;
 880                         break;
 881                 case IIO_VAL_INT_PLUS_NANO:
 882                         fract_mult = 100000000;
 883                         break;
 884                 default:
 885                         return -EINVAL;
 886                 }
 887
 888         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 889         if (ret)
 890                 return ret;
 891
 892         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 893                                          integer, fract, this_attr->address);
 894         if (ret)
 895                 return ret;
 896
 897         return len;
 898 }
 899
 900 static
 901 int __iio_device_attr_init(struct device_attribute *dev_attr,
 902                            const char *postfix,
 903                            struct iio_chan_spec const *chan,
 904                            ssize_t (*readfunc)(struct device *dev,
 905                                                struct device_attribute *attr,
 906                                                char *buf),
 907                            ssize_t (*writefunc)(struct device *dev,
 908                                                 struct device_attribute *attr,
 909                                                 const char *buf,
 910                                                 size_t len),
 911                            enum iio_shared_by shared_by)
 912 {
 913         int ret = 0;
 914         char *name = NULL;
 915         char *full_postfix;
 916         sysfs_attr_init(&dev_attr->attr);
 917
 918         /* Build up postfix of <extend_name>_<modifier>_postfix */
 919         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 920                 if (chan->extend_name)
 921                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 922                                                  iio_modifier_names[chan
 923                                                                     ->channel2],
 924                                                  chan->extend_name,
 925                                                  postfix);
 926                 else
 927                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 928                                                  iio_modifier_names[chan
 929                                                                     ->channel2],
 930                                                  postfix);
 931         } else {
 932                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 933                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 934                 else
 935                         full_postfix = kasprintf(GFP_KERNEL,
 936                                                  "%s_%s",
 937                                                  chan->extend_name,
 938                                                  postfix);
 939         }
 940         if (full_postfix == NULL)
 941                 return -ENOMEM;
 942
 943         if (chan->differential) { /* Differential can not have modifier */
 944                 switch (shared_by) {
 945                 case IIO_SHARED_BY_ALL:
 946                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 947                         break;
 948                 case IIO_SHARED_BY_DIR:
 949                         name = kasprintf(GFP_KERNEL, "%s_%s",
 950                                                 iio_direction[chan->output],
 951                                                 full_postfix);
 952                         break;
 953                 case IIO_SHARED_BY_TYPE:
 954                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 955                                             iio_direction[chan->output],
 956                                             iio_chan_type_name_spec[chan->type],
 957                                             iio_chan_type_name_spec[chan->type],
 958                                             full_postfix);
 959                         break;
 960                 case IIO_SEPARATE:
 961                         if (!chan->indexed) {
 962                                 WARN(1, "Differential channels must be indexed\n");
 963                                 ret = -EINVAL;
 964                                 goto error_free_full_postfix;
 965                         }
 966                         name = kasprintf(GFP_KERNEL,
 967                                             "%s_%s%d-%s%d_%s",
 968                                             iio_direction[chan->output],
 969                                             iio_chan_type_name_spec[chan->type],
 970                                             chan->channel,
 971                                             iio_chan_type_name_spec[chan->type],
 972                                             chan->channel2,
 973                                             full_postfix);
 974                         break;
 975                 }
 976         } else { /* Single ended */
 977                 switch (shared_by) {
 978                 case IIO_SHARED_BY_ALL:
 979                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 980                         break;
 981                 case IIO_SHARED_BY_DIR:
 982                         name = kasprintf(GFP_KERNEL, "%s_%s",
 983                                                 iio_direction[chan->output],
 984                                                 full_postfix);
 985                         break;
 986                 case IIO_SHARED_BY_TYPE:
 987                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 988                                             iio_direction[chan->output],
 989                                             iio_chan_type_name_spec[chan->type],
 990                                             full_postfix);
 991                         break;
 992
 993                 case IIO_SEPARATE:
 994                         if (chan->indexed)
 995                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 996                                                     iio_direction[chan->output],
 997                                                     iio_chan_type_name_spec[chan->type],
 998                                                     chan->channel,
 999                                                     full_postfix);
1000                         else
1001                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1002                                                     iio_direction[chan->output],
1003                                                     iio_chan_type_name_spec[chan->type],
1004                                                     full_postfix);
1005                         break;
1006                 }
1007         }
1008         if (name == NULL) {
1009                 ret = -ENOMEM;
1010                 goto error_free_full_postfix;
1011         }
1012         dev_attr->attr.name = name;
1013
1014         if (readfunc) {
1015                 dev_attr->attr.mode |= S_IRUGO;
1016                 dev_attr->show = readfunc;
1017         }
1018
1019         if (writefunc) {
1020                 dev_attr->attr.mode |= S_IWUSR;
1021                 dev_attr->store = writefunc;
1022         }
1023
1024 error_free_full_postfix:
1025         kfree(full_postfix);
1026
1027         return ret;
1028 }
1029
1030 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1031 {
1032         kfree(dev_attr->attr.name);
1033 }
1034
1035 int __iio_add_chan_devattr(const char *postfix,
1036                            struct iio_chan_spec const *chan,
1037                            ssize_t (*readfunc)(struct device *dev,
1038                                                struct device_attribute *attr,
1039                                                char *buf),
1040                            ssize_t (*writefunc)(struct device *dev,
1041                                                 struct device_attribute *attr,
1042                                                 const char *buf,
1043                                                 size_t len),
1044                            u64 mask,
1045                            enum iio_shared_by shared_by,
1046                            struct device *dev,
1047                            struct list_head *attr_list)
1048 {
1049         int ret;
1050         struct iio_dev_attr *iio_attr, *t;
1051
1052         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1053         if (iio_attr == NULL)
1054                 return -ENOMEM;
1055         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1056                                      postfix, chan,
1057                                      readfunc, writefunc, shared_by);
1058         if (ret)
1059                 goto error_iio_dev_attr_free;
1060         iio_attr->c = chan;
1061         iio_attr->address = mask;
1062         list_for_each_entry(t, attr_list, l)
1063                 if (strcmp(t->dev_attr.attr.name,
1064                            iio_attr->dev_attr.attr.name) == 0) {
1065                         if (shared_by == IIO_SEPARATE)
1066                                 dev_err(dev, "tried to double register : %s\n",
1067                                         t->dev_attr.attr.name);
1068                         ret = -EBUSY;
1069                         goto error_device_attr_deinit;
1070                 }
1071         list_add(&iio_attr->l, attr_list);
1072
1073         return 0;
1074
1075 error_device_attr_deinit:
1076         __iio_device_attr_deinit(&iio_attr->dev_attr);
1077 error_iio_dev_attr_free:
1078         kfree(iio_attr);
1079         return ret;
1080 }
1081
1082 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1083                                          struct iio_chan_spec const *chan,
1084                                          enum iio_shared_by shared_by,
1085                                          const long *infomask)
1086 {
1087         int i, ret, attrcount = 0;
1088
1089         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1090                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1091                         return -EINVAL;
1092                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1093                                              chan,
1094                                              &iio_read_channel_info,
1095                                              &iio_write_channel_info,
1096                                              i,
1097                                              shared_by,
1098                                              &indio_dev->dev,
1099                                              &indio_dev->channel_attr_list);
1100                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1101                         continue;
1102                 else if (ret < 0)
1103                         return ret;
1104                 attrcount++;
1105         }
1106
1107         return attrcount;
1108 }
1109
1110 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1111                                                struct iio_chan_spec const *chan,
1112                                                enum iio_shared_by shared_by,
1113                                                const long *infomask)
1114 {
1115         int i, ret, attrcount = 0;
1116         char *avail_postfix;
1117
1118         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1119                 avail_postfix = kasprintf(GFP_KERNEL,
1120                                           "%s_available",
1121                                           iio_chan_info_postfix[i]);
1122                 if (!avail_postfix)
1123                         return -ENOMEM;
1124
1125                 ret = __iio_add_chan_devattr(avail_postfix,
1126                                              chan,
1127                                              &iio_read_channel_info_avail,
1128                                              NULL,
1129                                              i,
1130                                              shared_by,
1131                                              &indio_dev->dev,
1132                                              &indio_dev->channel_attr_list);
1133                 kfree(avail_postfix);
1134                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1135                         continue;
1136                 else if (ret < 0)
1137                         return ret;
1138                 attrcount++;
1139         }
1140
1141         return attrcount;
1142 }
1143
1144 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1145                                         struct iio_chan_spec const *chan)
1146 {
1147         int ret, attrcount = 0;
1148         const struct iio_chan_spec_ext_info *ext_info;
1149
1150         if (chan->channel < 0)
1151                 return 0;
1152         ret = iio_device_add_info_mask_type(indio_dev, chan,
1153                                             IIO_SEPARATE,
1154                                             &chan->info_mask_separate);
1155         if (ret < 0)
1156                 return ret;
1157         attrcount += ret;
1158
1159         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1160                                                   IIO_SEPARATE,
1161                                                   &chan->
1162                                                   info_mask_separate_available);
1163         if (ret < 0)
1164                 return ret;
1165         attrcount += ret;
1166
1167         ret = iio_device_add_info_mask_type(indio_dev, chan,
1168                                             IIO_SHARED_BY_TYPE,
1169                                             &chan->info_mask_shared_by_type);
1170         if (ret < 0)
1171                 return ret;
1172         attrcount += ret;
1173
1174         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1175                                                   IIO_SHARED_BY_TYPE,
1176                                                   &chan->
1177                                                   info_mask_shared_by_type_available);
1178         if (ret < 0)
1179                 return ret;
1180         attrcount += ret;
1181
1182         ret = iio_device_add_info_mask_type(indio_dev, chan,
1183                                             IIO_SHARED_BY_DIR,
1184                                             &chan->info_mask_shared_by_dir);
1185         if (ret < 0)
1186                 return ret;
1187         attrcount += ret;
1188
1189         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1190                                                   IIO_SHARED_BY_DIR,
1191                                                   &chan->info_mask_shared_by_dir_available);
1192         if (ret < 0)
1193                 return ret;
1194         attrcount += ret;
1195
1196         ret = iio_device_add_info_mask_type(indio_dev, chan,
1197                                             IIO_SHARED_BY_ALL,
1198                                             &chan->info_mask_shared_by_all);
1199         if (ret < 0)
1200                 return ret;
1201         attrcount += ret;
1202
1203         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1204                                                   IIO_SHARED_BY_ALL,
1205                                                   &chan->info_mask_shared_by_all_available);
1206         if (ret < 0)
1207                 return ret;
1208         attrcount += ret;
1209
1210         if (chan->ext_info) {
1211                 unsigned int i = 0;
1212                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1213                         ret = __iio_add_chan_devattr(ext_info->name,
1214                                         chan,
1215                                         ext_info->read ?
1216                                             &iio_read_channel_ext_info : NULL,
1217                                         ext_info->write ?
1218                                             &iio_write_channel_ext_info : NULL,
1219                                         i,
1220                                         ext_info->shared,
1221                                         &indio_dev->dev,
1222                                         &indio_dev->channel_attr_list);
1223                         i++;
1224                         if (ret == -EBUSY && ext_info->shared)
1225                                 continue;
1226
1227                         if (ret)
1228                                 return ret;
1229
1230                         attrcount++;
1231                 }
1232         }
1233
1234         return attrcount;
1235 }
1236
1237 /**
1238  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1239  * @attr_list: List of IIO device attributes
1240  *
1241  * This function frees the memory allocated for each of the IIO device
1242  * attributes in the list.
1243  */
1244 void iio_free_chan_devattr_list(struct list_head *attr_list)
1245 {
1246         struct iio_dev_attr *p, *n;
1247
1248         list_for_each_entry_safe(p, n, attr_list, l) {
1249                 kfree(p->dev_attr.attr.name);
1250                 list_del(&p->l);
1251                 kfree(p);
1252         }
1253 }
1254
1255 static ssize_t iio_show_dev_name(struct device *dev,
1256                                  struct device_attribute *attr,
1257                                  char *buf)
1258 {
1259         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1260         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1261 }
1262
1263 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1264
1265 static ssize_t iio_show_timestamp_clock(struct device *dev,
1266                                         struct device_attribute *attr,
1267                                         char *buf)
1268 {
1269         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1270         const clockid_t clk = iio_device_get_clock(indio_dev);
1271         const char *name;
1272         ssize_t sz;
1273
1274         switch (clk) {
1275         case CLOCK_REALTIME:
1276                 name = "realtime\n";
1277                 sz = sizeof("realtime\n");
1278                 break;
1279         case CLOCK_MONOTONIC:
1280                 name = "monotonic\n";
1281                 sz = sizeof("monotonic\n");
1282                 break;
1283         case CLOCK_MONOTONIC_RAW:
1284                 name = "monotonic_raw\n";
1285                 sz = sizeof("monotonic_raw\n");
1286                 break;
1287         case CLOCK_REALTIME_COARSE:
1288                 name = "realtime_coarse\n";
1289                 sz = sizeof("realtime_coarse\n");
1290                 break;
1291         case CLOCK_MONOTONIC_COARSE:
1292                 name = "monotonic_coarse\n";
1293                 sz = sizeof("monotonic_coarse\n");
1294                 break;
1295         case CLOCK_BOOTTIME:
1296                 name = "boottime\n";
1297                 sz = sizeof("boottime\n");
1298                 break;
1299         case CLOCK_TAI:
1300                 name = "tai\n";
1301                 sz = sizeof("tai\n");
1302                 break;
1303         default:
1304                 BUG();
1305         }
1306
1307         memcpy(buf, name, sz);
1308         return sz;
1309 }
1310
1311 static ssize_t iio_store_timestamp_clock(struct device *dev,
1312                                          struct device_attribute *attr,
1313                                          const char *buf, size_t len)
1314 {
1315         clockid_t clk;
1316         int ret;
1317
1318         if (sysfs_streq(buf, "realtime"))
1319                 clk = CLOCK_REALTIME;
1320         else if (sysfs_streq(buf, "monotonic"))
1321                 clk = CLOCK_MONOTONIC;
1322         else if (sysfs_streq(buf, "monotonic_raw"))
1323                 clk = CLOCK_MONOTONIC_RAW;
1324         else if (sysfs_streq(buf, "realtime_coarse"))
1325                 clk = CLOCK_REALTIME_COARSE;
1326         else if (sysfs_streq(buf, "monotonic_coarse"))
1327                 clk = CLOCK_MONOTONIC_COARSE;
1328         else if (sysfs_streq(buf, "boottime"))
1329                 clk = CLOCK_BOOTTIME;
1330         else if (sysfs_streq(buf, "tai"))
1331                 clk = CLOCK_TAI;
1332         else
1333                 return -EINVAL;
1334
1335         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1336         if (ret)
1337                 return ret;
1338
1339         return len;
1340 }
1341
1342 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1343                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1344
1345 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1346 {
1347         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1348         struct iio_dev_attr *p;
1349         struct attribute **attr, *clk = NULL;
1350
1351         /* First count elements in any existing group */
1352         if (indio_dev->info->attrs) {
1353                 attr = indio_dev->info->attrs->attrs;
1354                 while (*attr++ != NULL)
1355                         attrcount_orig++;
1356         }
1357         attrcount = attrcount_orig;
1358         /*
1359          * New channel registration method - relies on the fact a group does
1360          * not need to be initialized if its name is NULL.
1361          */
1362         if (indio_dev->channels)
1363                 for (i = 0; i < indio_dev->num_channels; i++) {
1364                         const struct iio_chan_spec *chan =
1365                                 &indio_dev->channels[i];
1366
1367                         if (chan->type == IIO_TIMESTAMP)
1368                                 clk = &dev_attr_current_timestamp_clock.attr;
1369
1370                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1371                         if (ret < 0)
1372                                 goto error_clear_attrs;
1373                         attrcount += ret;
1374                 }
1375
1376         if (indio_dev->event_interface)
1377                 clk = &dev_attr_current_timestamp_clock.attr;
1378
1379         if (indio_dev->name)
1380                 attrcount++;
1381         if (clk)
1382                 attrcount++;
1383
1384         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1385                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1386                                                    GFP_KERNEL);
1387         if (indio_dev->chan_attr_group.attrs == NULL) {
1388                 ret = -ENOMEM;
1389                 goto error_clear_attrs;
1390         }
1391         /* Copy across original attributes */
1392         if (indio_dev->info->attrs)
1393                 memcpy(indio_dev->chan_attr_group.attrs,
1394                        indio_dev->info->attrs->attrs,
1395                        sizeof(indio_dev->chan_attr_group.attrs[0])
1396                        *attrcount_orig);
1397         attrn = attrcount_orig;
1398         /* Add all elements from the list. */
1399         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1400                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1401         if (indio_dev->name)
1402                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1403         if (clk)
1404                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1405
1406         indio_dev->groups[indio_dev->groupcounter++] =
1407                 &indio_dev->chan_attr_group;
1408
1409         return 0;
1410
1411 error_clear_attrs:
1412         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1413
1414         return ret;
1415 }
1416
1417 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1418 {
1419
1420         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1421         kfree(indio_dev->chan_attr_group.attrs);
1422         indio_dev->chan_attr_group.attrs = NULL;
1423 }
1424
1425 static void iio_dev_release(struct device *device)
1426 {
1427         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1428         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1429                 iio_device_unregister_trigger_consumer(indio_dev);
1430         iio_device_unregister_eventset(indio_dev);
1431         iio_device_unregister_sysfs(indio_dev);
1432
1433         iio_buffer_put(indio_dev->buffer);
1434
1435         ida_simple_remove(&iio_ida, indio_dev->id);
1436         kfree(indio_dev);
1437 }
1438
1439 struct device_type iio_device_type = {
1440         .name = "iio_device",
1441         .release = iio_dev_release,
1442 };
1443
1444 /**
1445  * iio_device_alloc() - allocate an iio_dev from a driver
1446  * @sizeof_priv:        Space to allocate for private structure.
1447  **/
1448 struct iio_dev *iio_device_alloc(int sizeof_priv)
1449 {
1450         struct iio_dev *dev;
1451         size_t alloc_size;
1452
1453         alloc_size = sizeof(struct iio_dev);
1454         if (sizeof_priv) {
1455                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1456                 alloc_size += sizeof_priv;
1457         }
1458         /* ensure 32-byte alignment of whole construct ? */
1459         alloc_size += IIO_ALIGN - 1;
1460
1461         dev = kzalloc(alloc_size, GFP_KERNEL);
1462
1463         if (dev) {
1464                 dev->dev.groups = dev->groups;
1465                 dev->dev.type = &iio_device_type;
1466                 dev->dev.bus = &iio_bus_type;
1467                 device_initialize(&dev->dev);
1468                 dev_set_drvdata(&dev->dev, (void *)dev);
1469                 mutex_init(&dev->mlock);
1470                 mutex_init(&dev->info_exist_lock);
1471                 INIT_LIST_HEAD(&dev->channel_attr_list);
1472
1473                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1474                 if (dev->id < 0) {
1475                         /* cannot use a dev_err as the name isn't available */
1476                         pr_err("failed to get device id\n");
1477                         kfree(dev);
1478                         return NULL;
1479                 }
1480                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1481                 INIT_LIST_HEAD(&dev->buffer_list);
1482         }
1483
1484         return dev;
1485 }
1486 EXPORT_SYMBOL(iio_device_alloc);
1487
1488 /**
1489  * iio_device_free() - free an iio_dev from a driver
1490  * @dev:                the iio_dev associated with the device
1491  **/
1492 void iio_device_free(struct iio_dev *dev)
1493 {
1494         if (dev)
1495                 put_device(&dev->dev);
1496 }
1497 EXPORT_SYMBOL(iio_device_free);
1498
1499 static void devm_iio_device_release(struct device *dev, void *res)
1500 {
1501         iio_device_free(*(struct iio_dev **)res);
1502 }
1503
1504 int devm_iio_device_match(struct device *dev, void *res, void *data)
1505 {
1506         struct iio_dev **r = res;
1507         if (!r || !*r) {
1508                 WARN_ON(!r || !*r);
1509                 return 0;
1510         }
1511         return *r == data;
1512 }
1513 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1514
1515 /**
1516  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1517  * @dev:                Device to allocate iio_dev for
1518  * @sizeof_priv:        Space to allocate for private structure.
1519  *
1520  * Managed iio_device_alloc. iio_dev allocated with this function is
1521  * automatically freed on driver detach.
1522  *
1523  * If an iio_dev allocated with this function needs to be freed separately,
1524  * devm_iio_device_free() must be used.
1525  *
1526  * RETURNS:
1527  * Pointer to allocated iio_dev on success, NULL on failure.
1528  */
1529 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1530 {
1531         struct iio_dev **ptr, *iio_dev;
1532
1533         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1534                            GFP_KERNEL);
1535         if (!ptr)
1536                 return NULL;
1537
1538         iio_dev = iio_device_alloc(sizeof_priv);
1539         if (iio_dev) {
1540                 *ptr = iio_dev;
1541                 devres_add(dev, ptr);
1542         } else {
1543                 devres_free(ptr);
1544         }
1545
1546         return iio_dev;
1547 }
1548 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1549
1550 /**
1551  * devm_iio_device_free - Resource-managed iio_device_free()
1552  * @dev:                Device this iio_dev belongs to
1553  * @iio_dev:            the iio_dev associated with the device
1554  *
1555  * Free iio_dev allocated with devm_iio_device_alloc().
1556  */
1557 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1558 {
1559         int rc;
1560
1561         rc = devres_release(dev, devm_iio_device_release,
1562                             devm_iio_device_match, iio_dev);
1563         WARN_ON(rc);
1564 }
1565 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1566
1567 /**
1568  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1569  * @inode:      Inode structure for identifying the device in the file system
1570  * @filp:       File structure for iio device used to keep and later access
1571  *              private data
1572  *
1573  * Return: 0 on success or -EBUSY if the device is already opened
1574  **/
1575 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1576 {
1577         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1578                                                 struct iio_dev, chrdev);
1579
1580         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1581                 return -EBUSY;
1582
1583         iio_device_get(indio_dev);
1584
1585         filp->private_data = indio_dev;
1586
1587         return 0;
1588 }
1589
1590 /**
1591  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1592  * @inode:      Inode structure pointer for the char device
1593  * @filp:       File structure pointer for the char device
1594  *
1595  * Return: 0 for successful release
1596  */
1597 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1598 {
1599         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1600                                                 struct iio_dev, chrdev);
1601         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1602         iio_device_put(indio_dev);
1603
1604         return 0;
1605 }
1606
1607 /* Somewhat of a cross file organization violation - ioctls here are actually
1608  * event related */
1609 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1610 {
1611         struct iio_dev *indio_dev = filp->private_data;
1612         int __user *ip = (int __user *)arg;
1613         int fd;
1614
1615         if (!indio_dev->info)
1616                 return -ENODEV;
1617
1618         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1619                 fd = iio_event_getfd(indio_dev);
1620                 if (fd < 0)
1621                         return fd;
1622                 if (copy_to_user(ip, &fd, sizeof(fd)))
1623                         return -EFAULT;
1624                 return 0;
1625         }
1626         return -EINVAL;
1627 }
1628
1629 static const struct file_operations iio_buffer_fileops = {
1630         .read = iio_buffer_read_first_n_outer_addr,
1631         .release = iio_chrdev_release,
1632         .open = iio_chrdev_open,
1633         .poll = iio_buffer_poll_addr,
1634         .owner = THIS_MODULE,
1635         .llseek = noop_llseek,
1636         .unlocked_ioctl = iio_ioctl,
1637         .compat_ioctl = iio_ioctl,
1638 };
1639
1640 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1641 {
1642         int i, j;
1643         const struct iio_chan_spec *channels = indio_dev->channels;
1644
1645         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1646                 return 0;
1647
1648         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1649                 if (channels[i].scan_index < 0)
1650                         continue;
1651                 for (j = i + 1; j < indio_dev->num_channels; j++)
1652                         if (channels[i].scan_index == channels[j].scan_index) {
1653                                 dev_err(&indio_dev->dev,
1654                                         "Duplicate scan index %d\n",
1655                                         channels[i].scan_index);
1656                                 return -EINVAL;
1657                         }
1658         }
1659
1660         return 0;
1661 }
1662
1663 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1664
1665 /**
1666  * iio_device_register() - register a device with the IIO subsystem
1667  * @indio_dev:          Device structure filled by the device driver
1668  **/
1669 int iio_device_register(struct iio_dev *indio_dev)
1670 {
1671         int ret;
1672
1673         /* If the calling driver did not initialize of_node, do it here */
1674         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1675                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1676
1677         ret = iio_check_unique_scan_index(indio_dev);
1678         if (ret < 0)
1679                 return ret;
1680
1681         /* configure elements for the chrdev */
1682         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1683
1684         ret = iio_device_register_debugfs(indio_dev);
1685         if (ret) {
1686                 dev_err(indio_dev->dev.parent,
1687                         "Failed to register debugfs interfaces\n");
1688                 return ret;
1689         }
1690
1691         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1692         if (ret) {
1693                 dev_err(indio_dev->dev.parent,
1694                         "Failed to create buffer sysfs interfaces\n");
1695                 goto error_unreg_debugfs;
1696         }
1697
1698         ret = iio_device_register_sysfs(indio_dev);
1699         if (ret) {
1700                 dev_err(indio_dev->dev.parent,
1701                         "Failed to register sysfs interfaces\n");
1702                 goto error_buffer_free_sysfs;
1703         }
1704         ret = iio_device_register_eventset(indio_dev);
1705         if (ret) {
1706                 dev_err(indio_dev->dev.parent,
1707                         "Failed to register event set\n");
1708                 goto error_free_sysfs;
1709         }
1710         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1711                 iio_device_register_trigger_consumer(indio_dev);
1712
1713         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1714                 indio_dev->setup_ops == NULL)
1715                 indio_dev->setup_ops = &noop_ring_setup_ops;
1716
1717         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1718         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1719
1720         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1721         if (ret < 0)
1722                 goto error_unreg_eventset;
1723
1724         return 0;
1725
1726 error_unreg_eventset:
1727         iio_device_unregister_eventset(indio_dev);
1728 error_free_sysfs:
1729         iio_device_unregister_sysfs(indio_dev);
1730 error_buffer_free_sysfs:
1731         iio_buffer_free_sysfs_and_mask(indio_dev);
1732 error_unreg_debugfs:
1733         iio_device_unregister_debugfs(indio_dev);
1734         return ret;
1735 }
1736 EXPORT_SYMBOL(iio_device_register);
1737
1738 /**
1739  * iio_device_unregister() - unregister a device from the IIO subsystem
1740  * @indio_dev:          Device structure representing the device.
1741  **/
1742 void iio_device_unregister(struct iio_dev *indio_dev)
1743 {
1744         mutex_lock(&indio_dev->info_exist_lock);
1745
1746         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1747
1748         iio_device_unregister_debugfs(indio_dev);
1749
1750         iio_disable_all_buffers(indio_dev);
1751
1752         indio_dev->info = NULL;
1753
1754         iio_device_wakeup_eventset(indio_dev);
1755         iio_buffer_wakeup_poll(indio_dev);
1756
1757         mutex_unlock(&indio_dev->info_exist_lock);
1758
1759         iio_buffer_free_sysfs_and_mask(indio_dev);
1760 }
1761 EXPORT_SYMBOL(iio_device_unregister);
1762
1763 static void devm_iio_device_unreg(struct device *dev, void *res)
1764 {
1765         iio_device_unregister(*(struct iio_dev **)res);
1766 }
1767
1768 /**
1769  * devm_iio_device_register - Resource-managed iio_device_register()
1770  * @dev:        Device to allocate iio_dev for
1771  * @indio_dev:  Device structure filled by the device driver
1772  *
1773  * Managed iio_device_register.  The IIO device registered with this
1774  * function is automatically unregistered on driver detach. This function
1775  * calls iio_device_register() internally. Refer to that function for more
1776  * information.
1777  *
1778  * If an iio_dev registered with this function needs to be unregistered
1779  * separately, devm_iio_device_unregister() must be used.
1780  *
1781  * RETURNS:
1782  * 0 on success, negative error number on failure.
1783  */
1784 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1785 {
1786         struct iio_dev **ptr;
1787         int ret;
1788
1789         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1790         if (!ptr)
1791                 return -ENOMEM;
1792
1793         *ptr = indio_dev;
1794         ret = iio_device_register(indio_dev);
1795         if (!ret)
1796                 devres_add(dev, ptr);
1797         else
1798                 devres_free(ptr);
1799
1800         return ret;
1801 }
1802 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1803
1804 /**
1805  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1806  * @dev:        Device this iio_dev belongs to
1807  * @indio_dev:  the iio_dev associated with the device
1808  *
1809  * Unregister iio_dev registered with devm_iio_device_register().
1810  */
1811 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1812 {
1813         int rc;
1814
1815         rc = devres_release(dev, devm_iio_device_unreg,
1816                             devm_iio_device_match, indio_dev);
1817         WARN_ON(rc);
1818 }
1819 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1820
1821 /**
1822  * iio_device_claim_direct_mode - Keep device in direct mode
1823  * @indio_dev:  the iio_dev associated with the device
1824  *
1825  * If the device is in direct mode it is guaranteed to stay
1826  * that way until iio_device_release_direct_mode() is called.
1827  *
1828  * Use with iio_device_release_direct_mode()
1829  *
1830  * Returns: 0 on success, -EBUSY on failure
1831  */
1832 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1833 {
1834         mutex_lock(&indio_dev->mlock);
1835
1836         if (iio_buffer_enabled(indio_dev)) {
1837                 mutex_unlock(&indio_dev->mlock);
1838                 return -EBUSY;
1839         }
1840         return 0;
1841 }
1842 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1843
1844 /**
1845  * iio_device_release_direct_mode - releases claim on direct mode
1846  * @indio_dev:  the iio_dev associated with the device
1847  *
1848  * Release the claim. Device is no longer guaranteed to stay
1849  * in direct mode.
1850  *
1851  * Use with iio_device_claim_direct_mode()
1852  */
1853 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1854 {
1855         mutex_unlock(&indio_dev->mlock);
1856 }
1857 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1858
1859 subsys_initcall(iio_init);
1860 module_exit(iio_exit);
1861
1862 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1863 MODULE_DESCRIPTION("Industrial I/O core");
1864 MODULE_LICENSE("GPL");