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
  36 /* IDA to assign each registered device a unique id */
  37 static DEFINE_IDA(iio_ida);
  38
  39 static dev_t iio_devt;
  40
  41 #define IIO_DEV_MAX 256
  42 struct bus_type iio_bus_type = {
  43         .name = "iio",
  44 };
  45 EXPORT_SYMBOL(iio_bus_type);
  46
  47 static struct dentry *iio_debugfs_dentry;
  48
  49 static const char * const iio_direction[] = {
  50         [0] = "in",
  51         [1] = "out",
  52 };
  53
  54 static const char * const iio_chan_type_name_spec[] = {
  55         [IIO_VOLTAGE] = "voltage",
  56         [IIO_CURRENT] = "current",
  57         [IIO_POWER] = "power",
  58         [IIO_ACCEL] = "accel",
  59         [IIO_ANGL_VEL] = "anglvel",
  60         [IIO_MAGN] = "magn",
  61         [IIO_LIGHT] = "illuminance",
  62         [IIO_INTENSITY] = "intensity",
  63         [IIO_PROXIMITY] = "proximity",
  64         [IIO_TEMP] = "temp",
  65         [IIO_INCLI] = "incli",
  66         [IIO_ROT] = "rot",
  67         [IIO_ANGL] = "angl",
  68         [IIO_TIMESTAMP] = "timestamp",
  69         [IIO_CAPACITANCE] = "capacitance",
  70         [IIO_ALTVOLTAGE] = "altvoltage",
  71         [IIO_CCT] = "cct",
  72         [IIO_PRESSURE] = "pressure",
  73         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  74         [IIO_ACTIVITY] = "activity",
  75         [IIO_STEPS] = "steps",
  76         [IIO_ENERGY] = "energy",
  77         [IIO_DISTANCE] = "distance",
  78         [IIO_VELOCITY] = "velocity",
  79         [IIO_CONCENTRATION] = "concentration",
  80         [IIO_RESISTANCE] = "resistance",
  81         [IIO_PH] = "ph",
  82         [IIO_UVINDEX] = "uvindex",
  83         [IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  84         [IIO_COUNT] = "count",
  85         [IIO_INDEX] = "index",
  86 };
  87
  88 static const char * const iio_modifier_names[] = {
  89         [IIO_MOD_X] = "x",
  90         [IIO_MOD_Y] = "y",
  91         [IIO_MOD_Z] = "z",
  92         [IIO_MOD_X_AND_Y] = "x&y",
  93         [IIO_MOD_X_AND_Z] = "x&z",
  94         [IIO_MOD_Y_AND_Z] = "y&z",
  95         [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
  96         [IIO_MOD_X_OR_Y] = "x|y",
  97         [IIO_MOD_X_OR_Z] = "x|z",
  98         [IIO_MOD_Y_OR_Z] = "y|z",
  99         [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 100         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 101         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 102         [IIO_MOD_LIGHT_BOTH] = "both",
 103         [IIO_MOD_LIGHT_IR] = "ir",
 104         [IIO_MOD_LIGHT_CLEAR] = "clear",
 105         [IIO_MOD_LIGHT_RED] = "red",
 106         [IIO_MOD_LIGHT_GREEN] = "green",
 107         [IIO_MOD_LIGHT_BLUE] = "blue",
 108         [IIO_MOD_LIGHT_UV] = "uv",
 109         [IIO_MOD_QUATERNION] = "quaternion",
 110         [IIO_MOD_TEMP_AMBIENT] = "ambient",
 111         [IIO_MOD_TEMP_OBJECT] = "object",
 112         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 113         [IIO_MOD_NORTH_TRUE] = "from_north_true",
 114         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 115         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 116         [IIO_MOD_RUNNING] = "running",
 117         [IIO_MOD_JOGGING] = "jogging",
 118         [IIO_MOD_WALKING] = "walking",
 119         [IIO_MOD_STILL] = "still",
 120         [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 121         [IIO_MOD_I] = "i",
 122         [IIO_MOD_Q] = "q",
 123         [IIO_MOD_CO2] = "co2",
 124         [IIO_MOD_VOC] = "voc",
 125 };
 126
 127 /* relies on pairs of these shared then separate */
 128 static const char * const iio_chan_info_postfix[] = {
 129         [IIO_CHAN_INFO_RAW] = "raw",
 130         [IIO_CHAN_INFO_PROCESSED] = "input",
 131         [IIO_CHAN_INFO_SCALE] = "scale",
 132         [IIO_CHAN_INFO_OFFSET] = "offset",
 133         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 134         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 135         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 136         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 137         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 138         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 139         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 140         = "filter_low_pass_3db_frequency",
 141         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 142         = "filter_high_pass_3db_frequency",
 143         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 144         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 145         [IIO_CHAN_INFO_PHASE] = "phase",
 146         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 147         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 148         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 149         [IIO_CHAN_INFO_ENABLE] = "en",
 150         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 151         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 152         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 153         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 154         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 155         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 156 };
 157
 158 /**
 159  * iio_find_channel_from_si() - get channel from its scan index
 160  * @indio_dev:          device
 161  * @si:                 scan index to match
 162  */
 163 const struct iio_chan_spec
 164 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 165 {
 166         int i;
 167
 168         for (i = 0; i < indio_dev->num_channels; i++)
 169                 if (indio_dev->channels[i].scan_index == si)
 170                         return &indio_dev->channels[i];
 171         return NULL;
 172 }
 173
 174 /* This turns up an awful lot */
 175 ssize_t iio_read_const_attr(struct device *dev,
 176                             struct device_attribute *attr,
 177                             char *buf)
 178 {
 179         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 180 }
 181 EXPORT_SYMBOL(iio_read_const_attr);
 182
 183 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 184 {
 185         int ret;
 186         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 187
 188         ret = mutex_lock_interruptible(&indio_dev->mlock);
 189         if (ret)
 190                 return ret;
 191         if ((ev_int && iio_event_enabled(ev_int)) ||
 192             iio_buffer_enabled(indio_dev)) {
 193                 mutex_unlock(&indio_dev->mlock);
 194                 return -EBUSY;
 195         }
 196         indio_dev->clock_id = clock_id;
 197         mutex_unlock(&indio_dev->mlock);
 198
 199         return 0;
 200 }
 201
 202 /**
 203  * iio_get_time_ns() - utility function to get a time stamp for events etc
 204  * @indio_dev: device
 205  */
 206 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 207 {
 208         struct timespec tp;
 209
 210         switch (iio_device_get_clock(indio_dev)) {
 211         case CLOCK_REALTIME:
 212                 ktime_get_real_ts(&tp);
 213                 break;
 214         case CLOCK_MONOTONIC:
 215                 ktime_get_ts(&tp);
 216                 break;
 217         case CLOCK_MONOTONIC_RAW:
 218                 getrawmonotonic(&tp);
 219                 break;
 220         case CLOCK_REALTIME_COARSE:
 221                 tp = current_kernel_time();
 222                 break;
 223         case CLOCK_MONOTONIC_COARSE:
 224                 tp = get_monotonic_coarse();
 225                 break;
 226         case CLOCK_BOOTTIME:
 227                 get_monotonic_boottime(&tp);
 228                 break;
 229         case CLOCK_TAI:
 230                 timekeeping_clocktai(&tp);
 231                 break;
 232         default:
 233                 BUG();
 234         }
 235
 236         return timespec_to_ns(&tp);
 237 }
 238 EXPORT_SYMBOL(iio_get_time_ns);
 239
 240 /**
 241  * iio_get_time_res() - utility function to get time stamp clock resolution in
 242  *                      nano seconds.
 243  * @indio_dev: device
 244  */
 245 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 246 {
 247         switch (iio_device_get_clock(indio_dev)) {
 248         case CLOCK_REALTIME:
 249         case CLOCK_MONOTONIC:
 250         case CLOCK_MONOTONIC_RAW:
 251         case CLOCK_BOOTTIME:
 252         case CLOCK_TAI:
 253                 return hrtimer_resolution;
 254         case CLOCK_REALTIME_COARSE:
 255         case CLOCK_MONOTONIC_COARSE:
 256                 return LOW_RES_NSEC;
 257         default:
 258                 BUG();
 259         }
 260 }
 261 EXPORT_SYMBOL(iio_get_time_res);
 262
 263 static int __init iio_init(void)
 264 {
 265         int ret;
 266
 267         /* Register sysfs bus */
 268         ret  = bus_register(&iio_bus_type);
 269         if (ret < 0) {
 270                 pr_err("could not register bus type\n");
 271                 goto error_nothing;
 272         }
 273
 274         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 275         if (ret < 0) {
 276                 pr_err("failed to allocate char dev region\n");
 277                 goto error_unregister_bus_type;
 278         }
 279
 280         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 281
 282         return 0;
 283
 284 error_unregister_bus_type:
 285         bus_unregister(&iio_bus_type);
 286 error_nothing:
 287         return ret;
 288 }
 289
 290 static void __exit iio_exit(void)
 291 {
 292         if (iio_devt)
 293                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 294         bus_unregister(&iio_bus_type);
 295         debugfs_remove(iio_debugfs_dentry);
 296 }
 297
 298 #if defined(CONFIG_DEBUG_FS)
 299 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 300                               size_t count, loff_t *ppos)
 301 {
 302         struct iio_dev *indio_dev = file->private_data;
 303         char buf[20];
 304         unsigned val = 0;
 305         ssize_t len;
 306         int ret;
 307
 308         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 309                                                   indio_dev->cached_reg_addr,
 310                                                   0, &val);
 311         if (ret)
 312                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 313
 314         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 315
 316         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 317 }
 318
 319 static ssize_t iio_debugfs_write_reg(struct file *file,
 320                      const char __user *userbuf, size_t count, loff_t *ppos)
 321 {
 322         struct iio_dev *indio_dev = file->private_data;
 323         unsigned reg, val;
 324         char buf[80];
 325         int ret;
 326
 327         count = min_t(size_t, count, (sizeof(buf)-1));
 328         if (copy_from_user(buf, userbuf, count))
 329                 return -EFAULT;
 330
 331         buf[count] = 0;
 332
 333         ret = sscanf(buf, "%i %i", &reg, &val);
 334
 335         switch (ret) {
 336         case 1:
 337                 indio_dev->cached_reg_addr = reg;
 338                 break;
 339         case 2:
 340                 indio_dev->cached_reg_addr = reg;
 341                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 342                                                           val, NULL);
 343                 if (ret) {
 344                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 345                                 __func__);
 346                         return ret;
 347                 }
 348                 break;
 349         default:
 350                 return -EINVAL;
 351         }
 352
 353         return count;
 354 }
 355
 356 static const struct file_operations iio_debugfs_reg_fops = {
 357         .open = simple_open,
 358         .read = iio_debugfs_read_reg,
 359         .write = iio_debugfs_write_reg,
 360 };
 361
 362 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 363 {
 364         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 365 }
 366
 367 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 368 {
 369         struct dentry *d;
 370
 371         if (indio_dev->info->debugfs_reg_access == NULL)
 372                 return 0;
 373
 374         if (!iio_debugfs_dentry)
 375                 return 0;
 376
 377         indio_dev->debugfs_dentry =
 378                 debugfs_create_dir(dev_name(&indio_dev->dev),
 379                                    iio_debugfs_dentry);
 380         if (indio_dev->debugfs_dentry == NULL) {
 381                 dev_warn(indio_dev->dev.parent,
 382                          "Failed to create debugfs directory\n");
 383                 return -EFAULT;
 384         }
 385
 386         d = debugfs_create_file("direct_reg_access", 0644,
 387                                 indio_dev->debugfs_dentry,
 388                                 indio_dev, &iio_debugfs_reg_fops);
 389         if (!d) {
 390                 iio_device_unregister_debugfs(indio_dev);
 391                 return -ENOMEM;
 392         }
 393
 394         return 0;
 395 }
 396 #else
 397 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 398 {
 399         return 0;
 400 }
 401
 402 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 403 {
 404 }
 405 #endif /* CONFIG_DEBUG_FS */
 406
 407 static ssize_t iio_read_channel_ext_info(struct device *dev,
 408                                      struct device_attribute *attr,
 409                                      char *buf)
 410 {
 411         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 412         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 413         const struct iio_chan_spec_ext_info *ext_info;
 414
 415         ext_info = &this_attr->c->ext_info[this_attr->address];
 416
 417         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 418 }
 419
 420 static ssize_t iio_write_channel_ext_info(struct device *dev,
 421                                      struct device_attribute *attr,
 422                                      const char *buf,
 423                                          size_t len)
 424 {
 425         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 426         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 427         const struct iio_chan_spec_ext_info *ext_info;
 428
 429         ext_info = &this_attr->c->ext_info[this_attr->address];
 430
 431         return ext_info->write(indio_dev, ext_info->private,
 432                                this_attr->c, buf, len);
 433 }
 434
 435 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 436         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 437 {
 438         const struct iio_enum *e = (const struct iio_enum *)priv;
 439         unsigned int i;
 440         size_t len = 0;
 441
 442         if (!e->num_items)
 443                 return 0;
 444
 445         for (i = 0; i < e->num_items; ++i)
 446                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 447
 448         /* replace last space with a newline */
 449         buf[len - 1] = '\n';
 450
 451         return len;
 452 }
 453 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 454
 455 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 456         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 457 {
 458         const struct iio_enum *e = (const struct iio_enum *)priv;
 459         int i;
 460
 461         if (!e->get)
 462                 return -EINVAL;
 463
 464         i = e->get(indio_dev, chan);
 465         if (i < 0)
 466                 return i;
 467         else if (i >= e->num_items)
 468                 return -EINVAL;
 469
 470         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 471 }
 472 EXPORT_SYMBOL_GPL(iio_enum_read);
 473
 474 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 475         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 476         size_t len)
 477 {
 478         const struct iio_enum *e = (const struct iio_enum *)priv;
 479         unsigned int i;
 480         int ret;
 481
 482         if (!e->set)
 483                 return -EINVAL;
 484
 485         for (i = 0; i < e->num_items; i++) {
 486                 if (sysfs_streq(buf, e->items[i]))
 487                         break;
 488         }
 489
 490         if (i == e->num_items)
 491                 return -EINVAL;
 492
 493         ret = e->set(indio_dev, chan, i);
 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  * of_iio_read_mount_matrix() - retrieve iio device mounting matrix from
 535  *                              device-tree "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 #ifdef CONFIG_OF
 546 int of_iio_read_mount_matrix(const struct device *dev,
 547                              const char *propname,
 548                              struct iio_mount_matrix *matrix)
 549 {
 550         if (dev->of_node) {
 551                 int err = of_property_read_string_array(dev->of_node,
 552                                 propname, matrix->rotation,
 553                                 ARRAY_SIZE(iio_mount_idmatrix.rotation));
 554
 555                 if (err == ARRAY_SIZE(iio_mount_idmatrix.rotation))
 556                         return 0;
 557
 558                 if (err >= 0)
 559                         /* Invalid number of matrix entries. */
 560                         return -EINVAL;
 561
 562                 if (err != -EINVAL)
 563                         /* Invalid matrix declaration format. */
 564                         return err;
 565         }
 566
 567         /* Matrix was not declared at all: fallback to identity. */
 568         return iio_setup_mount_idmatrix(dev, matrix);
 569 }
 570 #else
 571 int of_iio_read_mount_matrix(const struct device *dev,
 572                              const char *propname,
 573                              struct iio_mount_matrix *matrix)
 574 {
 575         return iio_setup_mount_idmatrix(dev, matrix);
 576 }
 577 #endif
 578 EXPORT_SYMBOL(of_iio_read_mount_matrix);
 579
 580 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 581                                   int size, const int *vals)
 582 {
 583         unsigned long long tmp;
 584         int tmp0, tmp1;
 585         bool scale_db = false;
 586
 587         switch (type) {
 588         case IIO_VAL_INT:
 589                 return snprintf(buf, len, "%d", vals[0]);
 590         case IIO_VAL_INT_PLUS_MICRO_DB:
 591                 scale_db = true;
 592         case IIO_VAL_INT_PLUS_MICRO:
 593                 if (vals[1] < 0)
 594                         return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 595                                         -vals[1], scale_db ? " dB" : "");
 596                 else
 597                         return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 598                                         scale_db ? " dB" : "");
 599         case IIO_VAL_INT_PLUS_NANO:
 600                 if (vals[1] < 0)
 601                         return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 602                                         -vals[1]);
 603                 else
 604                         return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 605         case IIO_VAL_FRACTIONAL:
 606                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 607                 tmp1 = vals[1];
 608                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 609                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 610         case IIO_VAL_FRACTIONAL_LOG2:
 611                 tmp = (s64)vals[0] * 1000000000LL >> vals[1];
 612                 tmp1 = do_div(tmp, 1000000000LL);
 613                 tmp0 = tmp;
 614                 return snprintf(buf, len, "%d.%09u", tmp0, tmp1);
 615         case IIO_VAL_INT_MULTIPLE:
 616         {
 617                 int i;
 618                 int l = 0;
 619
 620                 for (i = 0; i < size; ++i) {
 621                         l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 622                         if (l >= len)
 623                                 break;
 624                 }
 625                 return l;
 626         }
 627         default:
 628                 return 0;
 629         }
 630 }
 631
 632 /**
 633  * iio_format_value() - Formats a IIO value into its string representation
 634  * @buf:        The buffer to which the formatted value gets written
 635  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 636  * @type:       One of the IIO_VAL_... constants. This decides how the val
 637  *              and val2 parameters are formatted.
 638  * @size:       Number of IIO value entries contained in vals
 639  * @vals:       Pointer to the values, exact meaning depends on the
 640  *              type parameter.
 641  *
 642  * Return: 0 by default, a negative number on failure or the
 643  *         total number of characters written for a type that belongs
 644  *         to the IIO_VAL_... constant.
 645  */
 646 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 647 {
 648         ssize_t len;
 649
 650         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 651         if (len >= PAGE_SIZE - 1)
 652                 return -EFBIG;
 653
 654         return len + sprintf(buf + len, "\n");
 655 }
 656 EXPORT_SYMBOL_GPL(iio_format_value);
 657
 658 static ssize_t iio_read_channel_info(struct device *dev,
 659                                      struct device_attribute *attr,
 660                                      char *buf)
 661 {
 662         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 663         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 664         int vals[INDIO_MAX_RAW_ELEMENTS];
 665         int ret;
 666         int val_len = 2;
 667
 668         if (indio_dev->info->read_raw_multi)
 669                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 670                                                         INDIO_MAX_RAW_ELEMENTS,
 671                                                         vals, &val_len,
 672                                                         this_attr->address);
 673         else
 674                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 675                                     &vals[0], &vals[1], this_attr->address);
 676
 677         if (ret < 0)
 678                 return ret;
 679
 680         return iio_format_value(buf, ret, val_len, vals);
 681 }
 682
 683 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 684                                      int type, int length)
 685 {
 686         int i;
 687         ssize_t len = 0;
 688
 689         switch (type) {
 690         case IIO_VAL_INT:
 691                 for (i = 0; i < length; i++) {
 692                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 693                                                   type, 1, &vals[i]);
 694                         if (len >= PAGE_SIZE)
 695                                 return -EFBIG;
 696                         if (i < length - 1)
 697                                 len += snprintf(buf + len, PAGE_SIZE - len,
 698                                                 " ");
 699                         else
 700                                 len += snprintf(buf + len, PAGE_SIZE - len,
 701                                                 "\n");
 702                         if (len >= PAGE_SIZE)
 703                                 return -EFBIG;
 704                 }
 705                 break;
 706         default:
 707                 for (i = 0; i < length / 2; i++) {
 708                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 709                                                   type, 2, &vals[i * 2]);
 710                         if (len >= PAGE_SIZE)
 711                                 return -EFBIG;
 712                         if (i < length / 2 - 1)
 713                                 len += snprintf(buf + len, PAGE_SIZE - len,
 714                                                 " ");
 715                         else
 716                                 len += snprintf(buf + len, PAGE_SIZE - len,
 717                                                 "\n");
 718                         if (len >= PAGE_SIZE)
 719                                 return -EFBIG;
 720                 }
 721         }
 722
 723         return len;
 724 }
 725
 726 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 727 {
 728         int i;
 729         ssize_t len;
 730
 731         len = snprintf(buf, PAGE_SIZE, "[");
 732         switch (type) {
 733         case IIO_VAL_INT:
 734                 for (i = 0; i < 3; i++) {
 735                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 736                                                   type, 1, &vals[i]);
 737                         if (len >= PAGE_SIZE)
 738                                 return -EFBIG;
 739                         if (i < 2)
 740                                 len += snprintf(buf + len, PAGE_SIZE - len,
 741                                                 " ");
 742                         else
 743                                 len += snprintf(buf + len, PAGE_SIZE - len,
 744                                                 "]\n");
 745                         if (len >= PAGE_SIZE)
 746                                 return -EFBIG;
 747                 }
 748                 break;
 749         default:
 750                 for (i = 0; i < 3; i++) {
 751                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 752                                                   type, 2, &vals[i * 2]);
 753                         if (len >= PAGE_SIZE)
 754                                 return -EFBIG;
 755                         if (i < 2)
 756                                 len += snprintf(buf + len, PAGE_SIZE - len,
 757                                                 " ");
 758                         else
 759                                 len += snprintf(buf + len, PAGE_SIZE - len,
 760                                                 "]\n");
 761                         if (len >= PAGE_SIZE)
 762                                 return -EFBIG;
 763                 }
 764         }
 765
 766         return len;
 767 }
 768
 769 static ssize_t iio_read_channel_info_avail(struct device *dev,
 770                                            struct device_attribute *attr,
 771                                            char *buf)
 772 {
 773         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 774         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 775         const int *vals;
 776         int ret;
 777         int length;
 778         int type;
 779
 780         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 781                                           &vals, &type, &length,
 782                                           this_attr->address);
 783
 784         if (ret < 0)
 785                 return ret;
 786         switch (ret) {
 787         case IIO_AVAIL_LIST:
 788                 return iio_format_avail_list(buf, vals, type, length);
 789         case IIO_AVAIL_RANGE:
 790                 return iio_format_avail_range(buf, vals, type);
 791         default:
 792                 return -EINVAL;
 793         }
 794 }
 795
 796 /**
 797  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 798  * @str: The string to parse
 799  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 800  * @integer: The integer part of the number
 801  * @fract: The fractional part of the number
 802  *
 803  * Returns 0 on success, or a negative error code if the string could not be
 804  * parsed.
 805  */
 806 int iio_str_to_fixpoint(const char *str, int fract_mult,
 807         int *integer, int *fract)
 808 {
 809         int i = 0, f = 0;
 810         bool integer_part = true, negative = false;
 811
 812         if (fract_mult == 0) {
 813                 *fract = 0;
 814
 815                 return kstrtoint(str, 0, integer);
 816         }
 817
 818         if (str[0] == '-') {
 819                 negative = true;
 820                 str++;
 821         } else if (str[0] == '+') {
 822                 str++;
 823         }
 824
 825         while (*str) {
 826                 if ('0' <= *str && *str <= '9') {
 827                         if (integer_part) {
 828                                 i = i * 10 + *str - '0';
 829                         } else {
 830                                 f += fract_mult * (*str - '0');
 831                                 fract_mult /= 10;
 832                         }
 833                 } else if (*str == '\n') {
 834                         if (*(str + 1) == '\0')
 835                                 break;
 836                         else
 837                                 return -EINVAL;
 838                 } else if (*str == '.' && integer_part) {
 839                         integer_part = false;
 840                 } else {
 841                         return -EINVAL;
 842                 }
 843                 str++;
 844         }
 845
 846         if (negative) {
 847                 if (i)
 848                         i = -i;
 849                 else
 850                         f = -f;
 851         }
 852
 853         *integer = i;
 854         *fract = f;
 855
 856         return 0;
 857 }
 858 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 859
 860 static ssize_t iio_write_channel_info(struct device *dev,
 861                                       struct device_attribute *attr,
 862                                       const char *buf,
 863                                       size_t len)
 864 {
 865         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 866         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 867         int ret, fract_mult = 100000;
 868         int integer, fract;
 869
 870         /* Assumes decimal - precision based on number of digits */
 871         if (!indio_dev->info->write_raw)
 872                 return -EINVAL;
 873
 874         if (indio_dev->info->write_raw_get_fmt)
 875                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 876                         this_attr->c, this_attr->address)) {
 877                 case IIO_VAL_INT:
 878                         fract_mult = 0;
 879                         break;
 880                 case IIO_VAL_INT_PLUS_MICRO:
 881                         fract_mult = 100000;
 882                         break;
 883                 case IIO_VAL_INT_PLUS_NANO:
 884                         fract_mult = 100000000;
 885                         break;
 886                 default:
 887                         return -EINVAL;
 888                 }
 889
 890         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 891         if (ret)
 892                 return ret;
 893
 894         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 895                                          integer, fract, this_attr->address);
 896         if (ret)
 897                 return ret;
 898
 899         return len;
 900 }
 901
 902 static
 903 int __iio_device_attr_init(struct device_attribute *dev_attr,
 904                            const char *postfix,
 905                            struct iio_chan_spec const *chan,
 906                            ssize_t (*readfunc)(struct device *dev,
 907                                                struct device_attribute *attr,
 908                                                char *buf),
 909                            ssize_t (*writefunc)(struct device *dev,
 910                                                 struct device_attribute *attr,
 911                                                 const char *buf,
 912                                                 size_t len),
 913                            enum iio_shared_by shared_by)
 914 {
 915         int ret = 0;
 916         char *name = NULL;
 917         char *full_postfix;
 918         sysfs_attr_init(&dev_attr->attr);
 919
 920         /* Build up postfix of <extend_name>_<modifier>_postfix */
 921         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 922                 if (chan->extend_name)
 923                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 924                                                  iio_modifier_names[chan
 925                                                                     ->channel2],
 926                                                  chan->extend_name,
 927                                                  postfix);
 928                 else
 929                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 930                                                  iio_modifier_names[chan
 931                                                                     ->channel2],
 932                                                  postfix);
 933         } else {
 934                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 935                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 936                 else
 937                         full_postfix = kasprintf(GFP_KERNEL,
 938                                                  "%s_%s",
 939                                                  chan->extend_name,
 940                                                  postfix);
 941         }
 942         if (full_postfix == NULL)
 943                 return -ENOMEM;
 944
 945         if (chan->differential) { /* Differential can not have modifier */
 946                 switch (shared_by) {
 947                 case IIO_SHARED_BY_ALL:
 948                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 949                         break;
 950                 case IIO_SHARED_BY_DIR:
 951                         name = kasprintf(GFP_KERNEL, "%s_%s",
 952                                                 iio_direction[chan->output],
 953                                                 full_postfix);
 954                         break;
 955                 case IIO_SHARED_BY_TYPE:
 956                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 957                                             iio_direction[chan->output],
 958                                             iio_chan_type_name_spec[chan->type],
 959                                             iio_chan_type_name_spec[chan->type],
 960                                             full_postfix);
 961                         break;
 962                 case IIO_SEPARATE:
 963                         if (!chan->indexed) {
 964                                 WARN(1, "Differential channels must be indexed\n");
 965                                 ret = -EINVAL;
 966                                 goto error_free_full_postfix;
 967                         }
 968                         name = kasprintf(GFP_KERNEL,
 969                                             "%s_%s%d-%s%d_%s",
 970                                             iio_direction[chan->output],
 971                                             iio_chan_type_name_spec[chan->type],
 972                                             chan->channel,
 973                                             iio_chan_type_name_spec[chan->type],
 974                                             chan->channel2,
 975                                             full_postfix);
 976                         break;
 977                 }
 978         } else { /* Single ended */
 979                 switch (shared_by) {
 980                 case IIO_SHARED_BY_ALL:
 981                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 982                         break;
 983                 case IIO_SHARED_BY_DIR:
 984                         name = kasprintf(GFP_KERNEL, "%s_%s",
 985                                                 iio_direction[chan->output],
 986                                                 full_postfix);
 987                         break;
 988                 case IIO_SHARED_BY_TYPE:
 989                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 990                                             iio_direction[chan->output],
 991                                             iio_chan_type_name_spec[chan->type],
 992                                             full_postfix);
 993                         break;
 994
 995                 case IIO_SEPARATE:
 996                         if (chan->indexed)
 997                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 998                                                     iio_direction[chan->output],
 999                                                     iio_chan_type_name_spec[chan->type],
1000                                                     chan->channel,
1001                                                     full_postfix);
1002                         else
1003                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1004                                                     iio_direction[chan->output],
1005                                                     iio_chan_type_name_spec[chan->type],
1006                                                     full_postfix);
1007                         break;
1008                 }
1009         }
1010         if (name == NULL) {
1011                 ret = -ENOMEM;
1012                 goto error_free_full_postfix;
1013         }
1014         dev_attr->attr.name = name;
1015
1016         if (readfunc) {
1017                 dev_attr->attr.mode |= S_IRUGO;
1018                 dev_attr->show = readfunc;
1019         }
1020
1021         if (writefunc) {
1022                 dev_attr->attr.mode |= S_IWUSR;
1023                 dev_attr->store = writefunc;
1024         }
1025
1026 error_free_full_postfix:
1027         kfree(full_postfix);
1028
1029         return ret;
1030 }
1031
1032 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1033 {
1034         kfree(dev_attr->attr.name);
1035 }
1036
1037 int __iio_add_chan_devattr(const char *postfix,
1038                            struct iio_chan_spec const *chan,
1039                            ssize_t (*readfunc)(struct device *dev,
1040                                                struct device_attribute *attr,
1041                                                char *buf),
1042                            ssize_t (*writefunc)(struct device *dev,
1043                                                 struct device_attribute *attr,
1044                                                 const char *buf,
1045                                                 size_t len),
1046                            u64 mask,
1047                            enum iio_shared_by shared_by,
1048                            struct device *dev,
1049                            struct list_head *attr_list)
1050 {
1051         int ret;
1052         struct iio_dev_attr *iio_attr, *t;
1053
1054         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1055         if (iio_attr == NULL)
1056                 return -ENOMEM;
1057         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1058                                      postfix, chan,
1059                                      readfunc, writefunc, shared_by);
1060         if (ret)
1061                 goto error_iio_dev_attr_free;
1062         iio_attr->c = chan;
1063         iio_attr->address = mask;
1064         list_for_each_entry(t, attr_list, l)
1065                 if (strcmp(t->dev_attr.attr.name,
1066                            iio_attr->dev_attr.attr.name) == 0) {
1067                         if (shared_by == IIO_SEPARATE)
1068                                 dev_err(dev, "tried to double register : %s\n",
1069                                         t->dev_attr.attr.name);
1070                         ret = -EBUSY;
1071                         goto error_device_attr_deinit;
1072                 }
1073         list_add(&iio_attr->l, attr_list);
1074
1075         return 0;
1076
1077 error_device_attr_deinit:
1078         __iio_device_attr_deinit(&iio_attr->dev_attr);
1079 error_iio_dev_attr_free:
1080         kfree(iio_attr);
1081         return ret;
1082 }
1083
1084 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1085                                          struct iio_chan_spec const *chan,
1086                                          enum iio_shared_by shared_by,
1087                                          const long *infomask)
1088 {
1089         int i, ret, attrcount = 0;
1090
1091         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
1092                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1093                         return -EINVAL;
1094                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1095                                              chan,
1096                                              &iio_read_channel_info,
1097                                              &iio_write_channel_info,
1098                                              i,
1099                                              shared_by,
1100                                              &indio_dev->dev,
1101                                              &indio_dev->channel_attr_list);
1102                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1103                         continue;
1104                 else if (ret < 0)
1105                         return ret;
1106                 attrcount++;
1107         }
1108
1109         return attrcount;
1110 }
1111
1112 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1113                                                struct iio_chan_spec const *chan,
1114                                                enum iio_shared_by shared_by,
1115                                                const long *infomask)
1116 {
1117         int i, ret, attrcount = 0;
1118         char *avail_postfix;
1119
1120         for_each_set_bit(i, infomask, sizeof(infomask) * 8) {
1121                 avail_postfix = kasprintf(GFP_KERNEL,
1122                                           "%s_available",
1123                                           iio_chan_info_postfix[i]);
1124                 if (!avail_postfix)
1125                         return -ENOMEM;
1126
1127                 ret = __iio_add_chan_devattr(avail_postfix,
1128                                              chan,
1129                                              &iio_read_channel_info_avail,
1130                                              NULL,
1131                                              i,
1132                                              shared_by,
1133                                              &indio_dev->dev,
1134                                              &indio_dev->channel_attr_list);
1135                 kfree(avail_postfix);
1136                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1137                         continue;
1138                 else if (ret < 0)
1139                         return ret;
1140                 attrcount++;
1141         }
1142
1143         return attrcount;
1144 }
1145
1146 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1147                                         struct iio_chan_spec const *chan)
1148 {
1149         int ret, attrcount = 0;
1150         const struct iio_chan_spec_ext_info *ext_info;
1151
1152         if (chan->channel < 0)
1153                 return 0;
1154         ret = iio_device_add_info_mask_type(indio_dev, chan,
1155                                             IIO_SEPARATE,
1156                                             &chan->info_mask_separate);
1157         if (ret < 0)
1158                 return ret;
1159         attrcount += ret;
1160
1161         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1162                                                   IIO_SEPARATE,
1163                                                   &chan->
1164                                                   info_mask_separate_available);
1165         if (ret < 0)
1166                 return ret;
1167         attrcount += ret;
1168
1169         ret = iio_device_add_info_mask_type(indio_dev, chan,
1170                                             IIO_SHARED_BY_TYPE,
1171                                             &chan->info_mask_shared_by_type);
1172         if (ret < 0)
1173                 return ret;
1174         attrcount += ret;
1175
1176         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1177                                                   IIO_SHARED_BY_TYPE,
1178                                                   &chan->
1179                                                   info_mask_shared_by_type_available);
1180         if (ret < 0)
1181                 return ret;
1182         attrcount += ret;
1183
1184         ret = iio_device_add_info_mask_type(indio_dev, chan,
1185                                             IIO_SHARED_BY_DIR,
1186                                             &chan->info_mask_shared_by_dir);
1187         if (ret < 0)
1188                 return ret;
1189         attrcount += ret;
1190
1191         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1192                                                   IIO_SHARED_BY_DIR,
1193                                                   &chan->info_mask_shared_by_dir_available);
1194         if (ret < 0)
1195                 return ret;
1196         attrcount += ret;
1197
1198         ret = iio_device_add_info_mask_type(indio_dev, chan,
1199                                             IIO_SHARED_BY_ALL,
1200                                             &chan->info_mask_shared_by_all);
1201         if (ret < 0)
1202                 return ret;
1203         attrcount += ret;
1204
1205         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1206                                                   IIO_SHARED_BY_ALL,
1207                                                   &chan->info_mask_shared_by_all_available);
1208         if (ret < 0)
1209                 return ret;
1210         attrcount += ret;
1211
1212         if (chan->ext_info) {
1213                 unsigned int i = 0;
1214                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1215                         ret = __iio_add_chan_devattr(ext_info->name,
1216                                         chan,
1217                                         ext_info->read ?
1218                                             &iio_read_channel_ext_info : NULL,
1219                                         ext_info->write ?
1220                                             &iio_write_channel_ext_info : NULL,
1221                                         i,
1222                                         ext_info->shared,
1223                                         &indio_dev->dev,
1224                                         &indio_dev->channel_attr_list);
1225                         i++;
1226                         if (ret == -EBUSY && ext_info->shared)
1227                                 continue;
1228
1229                         if (ret)
1230                                 return ret;
1231
1232                         attrcount++;
1233                 }
1234         }
1235
1236         return attrcount;
1237 }
1238
1239 /**
1240  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1241  * @attr_list: List of IIO device attributes
1242  *
1243  * This function frees the memory allocated for each of the IIO device
1244  * attributes in the list.
1245  */
1246 void iio_free_chan_devattr_list(struct list_head *attr_list)
1247 {
1248         struct iio_dev_attr *p, *n;
1249
1250         list_for_each_entry_safe(p, n, attr_list, l) {
1251                 kfree(p->dev_attr.attr.name);
1252                 list_del(&p->l);
1253                 kfree(p);
1254         }
1255 }
1256
1257 static ssize_t iio_show_dev_name(struct device *dev,
1258                                  struct device_attribute *attr,
1259                                  char *buf)
1260 {
1261         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1262         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1263 }
1264
1265 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1266
1267 static ssize_t iio_show_timestamp_clock(struct device *dev,
1268                                         struct device_attribute *attr,
1269                                         char *buf)
1270 {
1271         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1272         const clockid_t clk = iio_device_get_clock(indio_dev);
1273         const char *name;
1274         ssize_t sz;
1275
1276         switch (clk) {
1277         case CLOCK_REALTIME:
1278                 name = "realtime\n";
1279                 sz = sizeof("realtime\n");
1280                 break;
1281         case CLOCK_MONOTONIC:
1282                 name = "monotonic\n";
1283                 sz = sizeof("monotonic\n");
1284                 break;
1285         case CLOCK_MONOTONIC_RAW:
1286                 name = "monotonic_raw\n";
1287                 sz = sizeof("monotonic_raw\n");
1288                 break;
1289         case CLOCK_REALTIME_COARSE:
1290                 name = "realtime_coarse\n";
1291                 sz = sizeof("realtime_coarse\n");
1292                 break;
1293         case CLOCK_MONOTONIC_COARSE:
1294                 name = "monotonic_coarse\n";
1295                 sz = sizeof("monotonic_coarse\n");
1296                 break;
1297         case CLOCK_BOOTTIME:
1298                 name = "boottime\n";
1299                 sz = sizeof("boottime\n");
1300                 break;
1301         case CLOCK_TAI:
1302                 name = "tai\n";
1303                 sz = sizeof("tai\n");
1304                 break;
1305         default:
1306                 BUG();
1307         }
1308
1309         memcpy(buf, name, sz);
1310         return sz;
1311 }
1312
1313 static ssize_t iio_store_timestamp_clock(struct device *dev,
1314                                          struct device_attribute *attr,
1315                                          const char *buf, size_t len)
1316 {
1317         clockid_t clk;
1318         int ret;
1319
1320         if (sysfs_streq(buf, "realtime"))
1321                 clk = CLOCK_REALTIME;
1322         else if (sysfs_streq(buf, "monotonic"))
1323                 clk = CLOCK_MONOTONIC;
1324         else if (sysfs_streq(buf, "monotonic_raw"))
1325                 clk = CLOCK_MONOTONIC_RAW;
1326         else if (sysfs_streq(buf, "realtime_coarse"))
1327                 clk = CLOCK_REALTIME_COARSE;
1328         else if (sysfs_streq(buf, "monotonic_coarse"))
1329                 clk = CLOCK_MONOTONIC_COARSE;
1330         else if (sysfs_streq(buf, "boottime"))
1331                 clk = CLOCK_BOOTTIME;
1332         else if (sysfs_streq(buf, "tai"))
1333                 clk = CLOCK_TAI;
1334         else
1335                 return -EINVAL;
1336
1337         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1338         if (ret)
1339                 return ret;
1340
1341         return len;
1342 }
1343
1344 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1345                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1346
1347 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1348 {
1349         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1350         struct iio_dev_attr *p;
1351         struct attribute **attr, *clk = NULL;
1352
1353         /* First count elements in any existing group */
1354         if (indio_dev->info->attrs) {
1355                 attr = indio_dev->info->attrs->attrs;
1356                 while (*attr++ != NULL)
1357                         attrcount_orig++;
1358         }
1359         attrcount = attrcount_orig;
1360         /*
1361          * New channel registration method - relies on the fact a group does
1362          * not need to be initialized if its name is NULL.
1363          */
1364         if (indio_dev->channels)
1365                 for (i = 0; i < indio_dev->num_channels; i++) {
1366                         const struct iio_chan_spec *chan =
1367                                 &indio_dev->channels[i];
1368
1369                         if (chan->type == IIO_TIMESTAMP)
1370                                 clk = &dev_attr_current_timestamp_clock.attr;
1371
1372                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1373                         if (ret < 0)
1374                                 goto error_clear_attrs;
1375                         attrcount += ret;
1376                 }
1377
1378         if (indio_dev->event_interface)
1379                 clk = &dev_attr_current_timestamp_clock.attr;
1380
1381         if (indio_dev->name)
1382                 attrcount++;
1383         if (clk)
1384                 attrcount++;
1385
1386         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1387                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1388                                                    GFP_KERNEL);
1389         if (indio_dev->chan_attr_group.attrs == NULL) {
1390                 ret = -ENOMEM;
1391                 goto error_clear_attrs;
1392         }
1393         /* Copy across original attributes */
1394         if (indio_dev->info->attrs)
1395                 memcpy(indio_dev->chan_attr_group.attrs,
1396                        indio_dev->info->attrs->attrs,
1397                        sizeof(indio_dev->chan_attr_group.attrs[0])
1398                        *attrcount_orig);
1399         attrn = attrcount_orig;
1400         /* Add all elements from the list. */
1401         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1402                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1403         if (indio_dev->name)
1404                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1405         if (clk)
1406                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1407
1408         indio_dev->groups[indio_dev->groupcounter++] =
1409                 &indio_dev->chan_attr_group;
1410
1411         return 0;
1412
1413 error_clear_attrs:
1414         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1415
1416         return ret;
1417 }
1418
1419 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1420 {
1421
1422         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1423         kfree(indio_dev->chan_attr_group.attrs);
1424         indio_dev->chan_attr_group.attrs = NULL;
1425 }
1426
1427 static void iio_dev_release(struct device *device)
1428 {
1429         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1430         if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1431                 iio_device_unregister_trigger_consumer(indio_dev);
1432         iio_device_unregister_eventset(indio_dev);
1433         iio_device_unregister_sysfs(indio_dev);
1434
1435         iio_buffer_put(indio_dev->buffer);
1436
1437         ida_simple_remove(&iio_ida, indio_dev->id);
1438         kfree(indio_dev);
1439 }
1440
1441 struct device_type iio_device_type = {
1442         .name = "iio_device",
1443         .release = iio_dev_release,
1444 };
1445
1446 /**
1447  * iio_device_alloc() - allocate an iio_dev from a driver
1448  * @sizeof_priv:        Space to allocate for private structure.
1449  **/
1450 struct iio_dev *iio_device_alloc(int sizeof_priv)
1451 {
1452         struct iio_dev *dev;
1453         size_t alloc_size;
1454
1455         alloc_size = sizeof(struct iio_dev);
1456         if (sizeof_priv) {
1457                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1458                 alloc_size += sizeof_priv;
1459         }
1460         /* ensure 32-byte alignment of whole construct ? */
1461         alloc_size += IIO_ALIGN - 1;
1462
1463         dev = kzalloc(alloc_size, GFP_KERNEL);
1464
1465         if (dev) {
1466                 dev->dev.groups = dev->groups;
1467                 dev->dev.type = &iio_device_type;
1468                 dev->dev.bus = &iio_bus_type;
1469                 device_initialize(&dev->dev);
1470                 dev_set_drvdata(&dev->dev, (void *)dev);
1471                 mutex_init(&dev->mlock);
1472                 mutex_init(&dev->info_exist_lock);
1473                 INIT_LIST_HEAD(&dev->channel_attr_list);
1474
1475                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1476                 if (dev->id < 0) {
1477                         /* cannot use a dev_err as the name isn't available */
1478                         pr_err("failed to get device id\n");
1479                         kfree(dev);
1480                         return NULL;
1481                 }
1482                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1483                 INIT_LIST_HEAD(&dev->buffer_list);
1484         }
1485
1486         return dev;
1487 }
1488 EXPORT_SYMBOL(iio_device_alloc);
1489
1490 /**
1491  * iio_device_free() - free an iio_dev from a driver
1492  * @dev:                the iio_dev associated with the device
1493  **/
1494 void iio_device_free(struct iio_dev *dev)
1495 {
1496         if (dev)
1497                 put_device(&dev->dev);
1498 }
1499 EXPORT_SYMBOL(iio_device_free);
1500
1501 static void devm_iio_device_release(struct device *dev, void *res)
1502 {
1503         iio_device_free(*(struct iio_dev **)res);
1504 }
1505
1506 int devm_iio_device_match(struct device *dev, void *res, void *data)
1507 {
1508         struct iio_dev **r = res;
1509         if (!r || !*r) {
1510                 WARN_ON(!r || !*r);
1511                 return 0;
1512         }
1513         return *r == data;
1514 }
1515 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1516
1517 /**
1518  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1519  * @dev:                Device to allocate iio_dev for
1520  * @sizeof_priv:        Space to allocate for private structure.
1521  *
1522  * Managed iio_device_alloc. iio_dev allocated with this function is
1523  * automatically freed on driver detach.
1524  *
1525  * If an iio_dev allocated with this function needs to be freed separately,
1526  * devm_iio_device_free() must be used.
1527  *
1528  * RETURNS:
1529  * Pointer to allocated iio_dev on success, NULL on failure.
1530  */
1531 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1532 {
1533         struct iio_dev **ptr, *iio_dev;
1534
1535         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1536                            GFP_KERNEL);
1537         if (!ptr)
1538                 return NULL;
1539
1540         iio_dev = iio_device_alloc(sizeof_priv);
1541         if (iio_dev) {
1542                 *ptr = iio_dev;
1543                 devres_add(dev, ptr);
1544         } else {
1545                 devres_free(ptr);
1546         }
1547
1548         return iio_dev;
1549 }
1550 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1551
1552 /**
1553  * devm_iio_device_free - Resource-managed iio_device_free()
1554  * @dev:                Device this iio_dev belongs to
1555  * @iio_dev:            the iio_dev associated with the device
1556  *
1557  * Free iio_dev allocated with devm_iio_device_alloc().
1558  */
1559 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1560 {
1561         int rc;
1562
1563         rc = devres_release(dev, devm_iio_device_release,
1564                             devm_iio_device_match, iio_dev);
1565         WARN_ON(rc);
1566 }
1567 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1568
1569 /**
1570  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1571  * @inode:      Inode structure for identifying the device in the file system
1572  * @filp:       File structure for iio device used to keep and later access
1573  *              private data
1574  *
1575  * Return: 0 on success or -EBUSY if the device is already opened
1576  **/
1577 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1578 {
1579         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1580                                                 struct iio_dev, chrdev);
1581
1582         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1583                 return -EBUSY;
1584
1585         iio_device_get(indio_dev);
1586
1587         filp->private_data = indio_dev;
1588
1589         return 0;
1590 }
1591
1592 /**
1593  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1594  * @inode:      Inode structure pointer for the char device
1595  * @filp:       File structure pointer for the char device
1596  *
1597  * Return: 0 for successful release
1598  */
1599 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1600 {
1601         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1602                                                 struct iio_dev, chrdev);
1603         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1604         iio_device_put(indio_dev);
1605
1606         return 0;
1607 }
1608
1609 /* Somewhat of a cross file organization violation - ioctls here are actually
1610  * event related */
1611 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1612 {
1613         struct iio_dev *indio_dev = filp->private_data;
1614         int __user *ip = (int __user *)arg;
1615         int fd;
1616
1617         if (!indio_dev->info)
1618                 return -ENODEV;
1619
1620         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1621                 fd = iio_event_getfd(indio_dev);
1622                 if (fd < 0)
1623                         return fd;
1624                 if (copy_to_user(ip, &fd, sizeof(fd)))
1625                         return -EFAULT;
1626                 return 0;
1627         }
1628         return -EINVAL;
1629 }
1630
1631 static const struct file_operations iio_buffer_fileops = {
1632         .read = iio_buffer_read_first_n_outer_addr,
1633         .release = iio_chrdev_release,
1634         .open = iio_chrdev_open,
1635         .poll = iio_buffer_poll_addr,
1636         .owner = THIS_MODULE,
1637         .llseek = noop_llseek,
1638         .unlocked_ioctl = iio_ioctl,
1639         .compat_ioctl = iio_ioctl,
1640 };
1641
1642 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1643 {
1644         int i, j;
1645         const struct iio_chan_spec *channels = indio_dev->channels;
1646
1647         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1648                 return 0;
1649
1650         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1651                 if (channels[i].scan_index < 0)
1652                         continue;
1653                 for (j = i + 1; j < indio_dev->num_channels; j++)
1654                         if (channels[i].scan_index == channels[j].scan_index) {
1655                                 dev_err(&indio_dev->dev,
1656                                         "Duplicate scan index %d\n",
1657                                         channels[i].scan_index);
1658                                 return -EINVAL;
1659                         }
1660         }
1661
1662         return 0;
1663 }
1664
1665 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1666
1667 /**
1668  * iio_device_register() - register a device with the IIO subsystem
1669  * @indio_dev:          Device structure filled by the device driver
1670  **/
1671 int iio_device_register(struct iio_dev *indio_dev)
1672 {
1673         int ret;
1674
1675         /* If the calling driver did not initialize of_node, do it here */
1676         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1677                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1678
1679         ret = iio_check_unique_scan_index(indio_dev);
1680         if (ret < 0)
1681                 return ret;
1682
1683         /* configure elements for the chrdev */
1684         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1685
1686         ret = iio_device_register_debugfs(indio_dev);
1687         if (ret) {
1688                 dev_err(indio_dev->dev.parent,
1689                         "Failed to register debugfs interfaces\n");
1690                 return ret;
1691         }
1692
1693         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1694         if (ret) {
1695                 dev_err(indio_dev->dev.parent,
1696                         "Failed to create buffer sysfs interfaces\n");
1697                 goto error_unreg_debugfs;
1698         }
1699
1700         ret = iio_device_register_sysfs(indio_dev);
1701         if (ret) {
1702                 dev_err(indio_dev->dev.parent,
1703                         "Failed to register sysfs interfaces\n");
1704                 goto error_buffer_free_sysfs;
1705         }
1706         ret = iio_device_register_eventset(indio_dev);
1707         if (ret) {
1708                 dev_err(indio_dev->dev.parent,
1709                         "Failed to register event set\n");
1710                 goto error_free_sysfs;
1711         }
1712         if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1713                 iio_device_register_trigger_consumer(indio_dev);
1714
1715         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1716                 indio_dev->setup_ops == NULL)
1717                 indio_dev->setup_ops = &noop_ring_setup_ops;
1718
1719         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1720         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1721         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1722         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1723         if (ret < 0)
1724                 goto error_unreg_eventset;
1725
1726         ret = device_add(&indio_dev->dev);
1727         if (ret < 0)
1728                 goto error_cdev_del;
1729
1730         return 0;
1731 error_cdev_del:
1732         cdev_del(&indio_dev->chrdev);
1733 error_unreg_eventset:
1734         iio_device_unregister_eventset(indio_dev);
1735 error_free_sysfs:
1736         iio_device_unregister_sysfs(indio_dev);
1737 error_buffer_free_sysfs:
1738         iio_buffer_free_sysfs_and_mask(indio_dev);
1739 error_unreg_debugfs:
1740         iio_device_unregister_debugfs(indio_dev);
1741         return ret;
1742 }
1743 EXPORT_SYMBOL(iio_device_register);
1744
1745 /**
1746  * iio_device_unregister() - unregister a device from the IIO subsystem
1747  * @indio_dev:          Device structure representing the device.
1748  **/
1749 void iio_device_unregister(struct iio_dev *indio_dev)
1750 {
1751         mutex_lock(&indio_dev->info_exist_lock);
1752
1753         device_del(&indio_dev->dev);
1754
1755         if (indio_dev->chrdev.dev)
1756                 cdev_del(&indio_dev->chrdev);
1757         iio_device_unregister_debugfs(indio_dev);
1758
1759         iio_disable_all_buffers(indio_dev);
1760
1761         indio_dev->info = NULL;
1762
1763         iio_device_wakeup_eventset(indio_dev);
1764         iio_buffer_wakeup_poll(indio_dev);
1765
1766         mutex_unlock(&indio_dev->info_exist_lock);
1767
1768         iio_buffer_free_sysfs_and_mask(indio_dev);
1769 }
1770 EXPORT_SYMBOL(iio_device_unregister);
1771
1772 static void devm_iio_device_unreg(struct device *dev, void *res)
1773 {
1774         iio_device_unregister(*(struct iio_dev **)res);
1775 }
1776
1777 /**
1778  * devm_iio_device_register - Resource-managed iio_device_register()
1779  * @dev:        Device to allocate iio_dev for
1780  * @indio_dev:  Device structure filled by the device driver
1781  *
1782  * Managed iio_device_register.  The IIO device registered with this
1783  * function is automatically unregistered on driver detach. This function
1784  * calls iio_device_register() internally. Refer to that function for more
1785  * information.
1786  *
1787  * If an iio_dev registered with this function needs to be unregistered
1788  * separately, devm_iio_device_unregister() must be used.
1789  *
1790  * RETURNS:
1791  * 0 on success, negative error number on failure.
1792  */
1793 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1794 {
1795         struct iio_dev **ptr;
1796         int ret;
1797
1798         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1799         if (!ptr)
1800                 return -ENOMEM;
1801
1802         *ptr = indio_dev;
1803         ret = iio_device_register(indio_dev);
1804         if (!ret)
1805                 devres_add(dev, ptr);
1806         else
1807                 devres_free(ptr);
1808
1809         return ret;
1810 }
1811 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1812
1813 /**
1814  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1815  * @dev:        Device this iio_dev belongs to
1816  * @indio_dev:  the iio_dev associated with the device
1817  *
1818  * Unregister iio_dev registered with devm_iio_device_register().
1819  */
1820 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1821 {
1822         int rc;
1823
1824         rc = devres_release(dev, devm_iio_device_unreg,
1825                             devm_iio_device_match, indio_dev);
1826         WARN_ON(rc);
1827 }
1828 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1829
1830 /**
1831  * iio_device_claim_direct_mode - Keep device in direct mode
1832  * @indio_dev:  the iio_dev associated with the device
1833  *
1834  * If the device is in direct mode it is guaranteed to stay
1835  * that way until iio_device_release_direct_mode() is called.
1836  *
1837  * Use with iio_device_release_direct_mode()
1838  *
1839  * Returns: 0 on success, -EBUSY on failure
1840  */
1841 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1842 {
1843         mutex_lock(&indio_dev->mlock);
1844
1845         if (iio_buffer_enabled(indio_dev)) {
1846                 mutex_unlock(&indio_dev->mlock);
1847                 return -EBUSY;
1848         }
1849         return 0;
1850 }
1851 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1852
1853 /**
1854  * iio_device_release_direct_mode - releases claim on direct mode
1855  * @indio_dev:  the iio_dev associated with the device
1856  *
1857  * Release the claim. Device is no longer guaranteed to stay
1858  * in direct mode.
1859  *
1860  * Use with iio_device_claim_direct_mode()
1861  */
1862 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1863 {
1864         mutex_unlock(&indio_dev->mlock);
1865 }
1866 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1867
1868 subsys_initcall(iio_init);
1869 module_exit(iio_exit);
1870
1871 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1872 MODULE_DESCRIPTION("Industrial I/O core");
1873 MODULE_LICENSE("GPL");