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
 316         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 317
 318         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 319 }
 320
 321 static ssize_t iio_debugfs_write_reg(struct file *file,
 322                      const char __user *userbuf, size_t count, loff_t *ppos)
 323 {
 324         struct iio_dev *indio_dev = file->private_data;
 325         unsigned reg, val;
 326         char buf[80];
 327         int ret;
 328
 329         count = min_t(size_t, count, (sizeof(buf)-1));
 330         if (copy_from_user(buf, userbuf, count))
 331                 return -EFAULT;
 332
 333         buf[count] = 0;
 334
 335         ret = sscanf(buf, "%i %i", &reg, &val);
 336
 337         switch (ret) {
 338         case 1:
 339                 indio_dev->cached_reg_addr = reg;
 340                 break;
 341         case 2:
 342                 indio_dev->cached_reg_addr = reg;
 343                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 344                                                           val, NULL);
 345                 if (ret) {
 346                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 347                                 __func__);
 348                         return ret;
 349                 }
 350                 break;
 351         default:
 352                 return -EINVAL;
 353         }
 354
 355         return count;
 356 }
 357
 358 static const struct file_operations iio_debugfs_reg_fops = {
 359         .open = simple_open,
 360         .read = iio_debugfs_read_reg,
 361         .write = iio_debugfs_write_reg,
 362 };
 363
 364 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 365 {
 366         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 367 }
 368
 369 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 370 {
 371         struct dentry *d;
 372
 373         if (indio_dev->info->debugfs_reg_access == NULL)
 374                 return 0;
 375
 376         if (!iio_debugfs_dentry)
 377                 return 0;
 378
 379         indio_dev->debugfs_dentry =
 380                 debugfs_create_dir(dev_name(&indio_dev->dev),
 381                                    iio_debugfs_dentry);
 382         if (indio_dev->debugfs_dentry == NULL) {
 383                 dev_warn(indio_dev->dev.parent,
 384                          "Failed to create debugfs directory\n");
 385                 return -EFAULT;
 386         }
 387
 388         d = debugfs_create_file("direct_reg_access", 0644,
 389                                 indio_dev->debugfs_dentry,
 390                                 indio_dev, &iio_debugfs_reg_fops);
 391         if (!d) {
 392                 iio_device_unregister_debugfs(indio_dev);
 393                 return -ENOMEM;
 394         }
 395
 396         return 0;
 397 }
 398 #else
 399 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 400 {
 401         return 0;
 402 }
 403
 404 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 405 {
 406 }
 407 #endif /* CONFIG_DEBUG_FS */
 408
 409 static ssize_t iio_read_channel_ext_info(struct device *dev,
 410                                      struct device_attribute *attr,
 411                                      char *buf)
 412 {
 413         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 414         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 415         const struct iio_chan_spec_ext_info *ext_info;
 416
 417         ext_info = &this_attr->c->ext_info[this_attr->address];
 418
 419         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 420 }
 421
 422 static ssize_t iio_write_channel_ext_info(struct device *dev,
 423                                      struct device_attribute *attr,
 424                                      const char *buf,
 425                                          size_t len)
 426 {
 427         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 428         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 429         const struct iio_chan_spec_ext_info *ext_info;
 430
 431         ext_info = &this_attr->c->ext_info[this_attr->address];
 432
 433         return ext_info->write(indio_dev, ext_info->private,
 434                                this_attr->c, buf, len);
 435 }
 436
 437 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 438         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 439 {
 440         const struct iio_enum *e = (const struct iio_enum *)priv;
 441         unsigned int i;
 442         size_t len = 0;
 443
 444         if (!e->num_items)
 445                 return 0;
 446
 447         for (i = 0; i < e->num_items; ++i)
 448                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 449
 450         /* replace last space with a newline */
 451         buf[len - 1] = '\n';
 452
 453         return len;
 454 }
 455 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 456
 457 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 458         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 459 {
 460         const struct iio_enum *e = (const struct iio_enum *)priv;
 461         int i;
 462
 463         if (!e->get)
 464                 return -EINVAL;
 465
 466         i = e->get(indio_dev, chan);
 467         if (i < 0)
 468                 return i;
 469         else if (i >= e->num_items)
 470                 return -EINVAL;
 471
 472         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 473 }
 474 EXPORT_SYMBOL_GPL(iio_enum_read);
 475
 476 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 477         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 478         size_t len)
 479 {
 480         const struct iio_enum *e = (const struct iio_enum *)priv;
 481         unsigned int i;
 482         int ret;
 483
 484         if (!e->set)
 485                 return -EINVAL;
 486
 487         for (i = 0; i < e->num_items; i++) {
 488                 if (sysfs_streq(buf, e->items[i]))
 489                         break;
 490         }
 491
 492         if (i == e->num_items)
 493                 return -EINVAL;
 494
 495         ret = e->set(indio_dev, chan, i);
 496         return ret ? ret : len;
 497 }
 498 EXPORT_SYMBOL_GPL(iio_enum_write);
 499
 500 static const struct iio_mount_matrix iio_mount_idmatrix = {
 501         .rotation = {
 502                 "1", "0", "0",
 503                 "0", "1", "0",
 504                 "0", "0", "1"
 505         }
 506 };
 507
 508 static int iio_setup_mount_idmatrix(const struct device *dev,
 509                                     struct iio_mount_matrix *matrix)
 510 {
 511         *matrix = iio_mount_idmatrix;
 512         dev_info(dev, "mounting matrix not found: using identity...\n");
 513         return 0;
 514 }
 515
 516 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 517                               const struct iio_chan_spec *chan, char *buf)
 518 {
 519         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 520                                               priv)(indio_dev, chan);
 521
 522         if (IS_ERR(mtx))
 523                 return PTR_ERR(mtx);
 524
 525         if (!mtx)
 526                 mtx = &iio_mount_idmatrix;
 527
 528         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 529                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 530                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 531                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 532 }
 533 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 534
 535 /**
 536  * of_iio_read_mount_matrix() - retrieve iio device mounting matrix from
 537  *                              device-tree "mount-matrix" property
 538  * @dev:        device the mounting matrix property is assigned to
 539  * @propname:   device specific mounting matrix property name
 540  * @matrix:     where to store retrieved matrix
 541  *
 542  * If device is assigned no mounting matrix property, a default 3x3 identity
 543  * matrix will be filled in.
 544  *
 545  * Return: 0 if success, or a negative error code on failure.
 546  */
 547 #ifdef CONFIG_OF
 548 int of_iio_read_mount_matrix(const struct device *dev,
 549                              const char *propname,
 550                              struct iio_mount_matrix *matrix)
 551 {
 552         if (dev->of_node) {
 553                 int err = of_property_read_string_array(dev->of_node,
 554                                 propname, matrix->rotation,
 555                                 ARRAY_SIZE(iio_mount_idmatrix.rotation));
 556
 557                 if (err == ARRAY_SIZE(iio_mount_idmatrix.rotation))
 558                         return 0;
 559
 560                 if (err >= 0)
 561                         /* Invalid number of matrix entries. */
 562                         return -EINVAL;
 563
 564                 if (err != -EINVAL)
 565                         /* Invalid matrix declaration format. */
 566                         return err;
 567         }
 568
 569         /* Matrix was not declared at all: fallback to identity. */
 570         return iio_setup_mount_idmatrix(dev, matrix);
 571 }
 572 #else
 573 int of_iio_read_mount_matrix(const struct device *dev,
 574                              const char *propname,
 575                              struct iio_mount_matrix *matrix)
 576 {
 577         return iio_setup_mount_idmatrix(dev, matrix);
 578 }
 579 #endif
 580 EXPORT_SYMBOL(of_iio_read_mount_matrix);
 581
 582 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 583                                   int size, const int *vals)
 584 {
 585         unsigned long long tmp;
 586         int tmp0, tmp1;
 587         bool scale_db = false;
 588
 589         switch (type) {
 590         case IIO_VAL_INT:
 591                 return snprintf(buf, len, "%d", vals[0]);
 592         case IIO_VAL_INT_PLUS_MICRO_DB:
 593                 scale_db = true;
 594         case IIO_VAL_INT_PLUS_MICRO:
 595                 if (vals[1] < 0)
 596                         return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 597                                         -vals[1], scale_db ? " dB" : "");
 598                 else
 599                         return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 600                                         scale_db ? " dB" : "");
 601         case IIO_VAL_INT_PLUS_NANO:
 602                 if (vals[1] < 0)
 603                         return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 604                                         -vals[1]);
 605                 else
 606                         return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 607         case IIO_VAL_FRACTIONAL:
 608                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 609                 tmp1 = vals[1];
 610                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 611                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 612         case IIO_VAL_FRACTIONAL_LOG2:
 613                 tmp = (s64)vals[0] * 1000000000LL >> vals[1];
 614                 tmp1 = do_div(tmp, 1000000000LL);
 615                 tmp0 = tmp;
 616                 return snprintf(buf, len, "%d.%09u", tmp0, tmp1);
 617         case IIO_VAL_INT_MULTIPLE:
 618         {
 619                 int i;
 620                 int l = 0;
 621
 622                 for (i = 0; i < size; ++i) {
 623                         l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 624                         if (l >= len)
 625                                 break;
 626                 }
 627                 return l;
 628         }
 629         default:
 630                 return 0;
 631         }
 632 }
 633
 634 /**
 635  * iio_format_value() - Formats a IIO value into its string representation
 636  * @buf:        The buffer to which the formatted value gets written
 637  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 638  * @type:       One of the IIO_VAL_... constants. This decides how the val
 639  *              and val2 parameters are formatted.
 640  * @size:       Number of IIO value entries contained in vals
 641  * @vals:       Pointer to the values, exact meaning depends on the
 642  *              type parameter.
 643  *
 644  * Return: 0 by default, a negative number on failure or the
 645  *         total number of characters written for a type that belongs
 646  *         to the IIO_VAL_... constant.
 647  */
 648 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 649 {
 650         ssize_t len;
 651
 652         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 653         if (len >= PAGE_SIZE - 1)
 654                 return -EFBIG;
 655
 656         return len + sprintf(buf + len, "\n");
 657 }
 658 EXPORT_SYMBOL_GPL(iio_format_value);
 659
 660 static ssize_t iio_read_channel_info(struct device *dev,
 661                                      struct device_attribute *attr,
 662                                      char *buf)
 663 {
 664         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 665         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 666         int vals[INDIO_MAX_RAW_ELEMENTS];
 667         int ret;
 668         int val_len = 2;
 669
 670         if (indio_dev->info->read_raw_multi)
 671                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 672                                                         INDIO_MAX_RAW_ELEMENTS,
 673                                                         vals, &val_len,
 674                                                         this_attr->address);
 675         else
 676                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 677                                     &vals[0], &vals[1], this_attr->address);
 678
 679         if (ret < 0)
 680                 return ret;
 681
 682         return iio_format_value(buf, ret, val_len, vals);
 683 }
 684
 685 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 686                                      int type, int length)
 687 {
 688         int i;
 689         ssize_t len = 0;
 690
 691         switch (type) {
 692         case IIO_VAL_INT:
 693                 for (i = 0; i < length; i++) {
 694                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 695                                                   type, 1, &vals[i]);
 696                         if (len >= PAGE_SIZE)
 697                                 return -EFBIG;
 698                         if (i < length - 1)
 699                                 len += snprintf(buf + len, PAGE_SIZE - len,
 700                                                 " ");
 701                         else
 702                                 len += snprintf(buf + len, PAGE_SIZE - len,
 703                                                 "\n");
 704                         if (len >= PAGE_SIZE)
 705                                 return -EFBIG;
 706                 }
 707                 break;
 708         default:
 709                 for (i = 0; i < length / 2; i++) {
 710                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 711                                                   type, 2, &vals[i * 2]);
 712                         if (len >= PAGE_SIZE)
 713                                 return -EFBIG;
 714                         if (i < length / 2 - 1)
 715                                 len += snprintf(buf + len, PAGE_SIZE - len,
 716                                                 " ");
 717                         else
 718                                 len += snprintf(buf + len, PAGE_SIZE - len,
 719                                                 "\n");
 720                         if (len >= PAGE_SIZE)
 721                                 return -EFBIG;
 722                 }
 723         }
 724
 725         return len;
 726 }
 727
 728 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 729 {
 730         int i;
 731         ssize_t len;
 732
 733         len = snprintf(buf, PAGE_SIZE, "[");
 734         switch (type) {
 735         case IIO_VAL_INT:
 736                 for (i = 0; i < 3; i++) {
 737                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 738                                                   type, 1, &vals[i]);
 739                         if (len >= PAGE_SIZE)
 740                                 return -EFBIG;
 741                         if (i < 2)
 742                                 len += snprintf(buf + len, PAGE_SIZE - len,
 743                                                 " ");
 744                         else
 745                                 len += snprintf(buf + len, PAGE_SIZE - len,
 746                                                 "]\n");
 747                         if (len >= PAGE_SIZE)
 748                                 return -EFBIG;
 749                 }
 750                 break;
 751         default:
 752                 for (i = 0; i < 3; i++) {
 753                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 754                                                   type, 2, &vals[i * 2]);
 755                         if (len >= PAGE_SIZE)
 756                                 return -EFBIG;
 757                         if (i < 2)
 758                                 len += snprintf(buf + len, PAGE_SIZE - len,
 759                                                 " ");
 760                         else
 761                                 len += snprintf(buf + len, PAGE_SIZE - len,
 762                                                 "]\n");
 763                         if (len >= PAGE_SIZE)
 764                                 return -EFBIG;
 765                 }
 766         }
 767
 768         return len;
 769 }
 770
 771 static ssize_t iio_read_channel_info_avail(struct device *dev,
 772                                            struct device_attribute *attr,
 773                                            char *buf)
 774 {
 775         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 776         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 777         const int *vals;
 778         int ret;
 779         int length;
 780         int type;
 781
 782         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 783                                           &vals, &type, &length,
 784                                           this_attr->address);
 785
 786         if (ret < 0)
 787                 return ret;
 788         switch (ret) {
 789         case IIO_AVAIL_LIST:
 790                 return iio_format_avail_list(buf, vals, type, length);
 791         case IIO_AVAIL_RANGE:
 792                 return iio_format_avail_range(buf, vals, type);
 793         default:
 794                 return -EINVAL;
 795         }
 796 }
 797
 798 /**
 799  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 800  * @str: The string to parse
 801  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 802  * @integer: The integer part of the number
 803  * @fract: The fractional part of the number
 804  *
 805  * Returns 0 on success, or a negative error code if the string could not be
 806  * parsed.
 807  */
 808 int iio_str_to_fixpoint(const char *str, int fract_mult,
 809         int *integer, int *fract)
 810 {
 811         int i = 0, f = 0;
 812         bool integer_part = true, negative = false;
 813
 814         if (fract_mult == 0) {
 815                 *fract = 0;
 816
 817                 return kstrtoint(str, 0, integer);
 818         }
 819
 820         if (str[0] == '-') {
 821                 negative = true;
 822                 str++;
 823         } else if (str[0] == '+') {
 824                 str++;
 825         }
 826
 827         while (*str) {
 828                 if ('0' <= *str && *str <= '9') {
 829                         if (integer_part) {
 830                                 i = i * 10 + *str - '0';
 831                         } else {
 832                                 f += fract_mult * (*str - '0');
 833                                 fract_mult /= 10;
 834                         }
 835                 } else if (*str == '\n') {
 836                         if (*(str + 1) == '\0')
 837                                 break;
 838                         else
 839                                 return -EINVAL;
 840                 } else if (*str == '.' && integer_part) {
 841                         integer_part = false;
 842                 } else {
 843                         return -EINVAL;
 844                 }
 845                 str++;
 846         }
 847
 848         if (negative) {
 849                 if (i)
 850                         i = -i;
 851                 else
 852                         f = -f;
 853         }
 854
 855         *integer = i;
 856         *fract = f;
 857
 858         return 0;
 859 }
 860 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 861
 862 static ssize_t iio_write_channel_info(struct device *dev,
 863                                       struct device_attribute *attr,
 864                                       const char *buf,
 865                                       size_t len)
 866 {
 867         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 868         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 869         int ret, fract_mult = 100000;
 870         int integer, fract;
 871
 872         /* Assumes decimal - precision based on number of digits */
 873         if (!indio_dev->info->write_raw)
 874                 return -EINVAL;
 875
 876         if (indio_dev->info->write_raw_get_fmt)
 877                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 878                         this_attr->c, this_attr->address)) {
 879                 case IIO_VAL_INT:
 880                         fract_mult = 0;
 881                         break;
 882                 case IIO_VAL_INT_PLUS_MICRO:
 883                         fract_mult = 100000;
 884                         break;
 885                 case IIO_VAL_INT_PLUS_NANO:
 886                         fract_mult = 100000000;
 887                         break;
 888                 default:
 889                         return -EINVAL;
 890                 }
 891
 892         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 893         if (ret)
 894                 return ret;
 895
 896         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 897                                          integer, fract, this_attr->address);
 898         if (ret)
 899                 return ret;
 900
 901         return len;
 902 }
 903
 904 static
 905 int __iio_device_attr_init(struct device_attribute *dev_attr,
 906                            const char *postfix,
 907                            struct iio_chan_spec const *chan,
 908                            ssize_t (*readfunc)(struct device *dev,
 909                                                struct device_attribute *attr,
 910                                                char *buf),
 911                            ssize_t (*writefunc)(struct device *dev,
 912                                                 struct device_attribute *attr,
 913                                                 const char *buf,
 914                                                 size_t len),
 915                            enum iio_shared_by shared_by)
 916 {
 917         int ret = 0;
 918         char *name = NULL;
 919         char *full_postfix;
 920         sysfs_attr_init(&dev_attr->attr);
 921
 922         /* Build up postfix of <extend_name>_<modifier>_postfix */
 923         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 924                 if (chan->extend_name)
 925                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 926                                                  iio_modifier_names[chan
 927                                                                     ->channel2],
 928                                                  chan->extend_name,
 929                                                  postfix);
 930                 else
 931                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 932                                                  iio_modifier_names[chan
 933                                                                     ->channel2],
 934                                                  postfix);
 935         } else {
 936                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 937                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 938                 else
 939                         full_postfix = kasprintf(GFP_KERNEL,
 940                                                  "%s_%s",
 941                                                  chan->extend_name,
 942                                                  postfix);
 943         }
 944         if (full_postfix == NULL)
 945                 return -ENOMEM;
 946
 947         if (chan->differential) { /* Differential can not have modifier */
 948                 switch (shared_by) {
 949                 case IIO_SHARED_BY_ALL:
 950                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 951                         break;
 952                 case IIO_SHARED_BY_DIR:
 953                         name = kasprintf(GFP_KERNEL, "%s_%s",
 954                                                 iio_direction[chan->output],
 955                                                 full_postfix);
 956                         break;
 957                 case IIO_SHARED_BY_TYPE:
 958                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 959                                             iio_direction[chan->output],
 960                                             iio_chan_type_name_spec[chan->type],
 961                                             iio_chan_type_name_spec[chan->type],
 962                                             full_postfix);
 963                         break;
 964                 case IIO_SEPARATE:
 965                         if (!chan->indexed) {
 966                                 WARN(1, "Differential channels must be indexed\n");
 967                                 ret = -EINVAL;
 968                                 goto error_free_full_postfix;
 969                         }
 970                         name = kasprintf(GFP_KERNEL,
 971                                             "%s_%s%d-%s%d_%s",
 972                                             iio_direction[chan->output],
 973                                             iio_chan_type_name_spec[chan->type],
 974                                             chan->channel,
 975                                             iio_chan_type_name_spec[chan->type],
 976                                             chan->channel2,
 977                                             full_postfix);
 978                         break;
 979                 }
 980         } else { /* Single ended */
 981                 switch (shared_by) {
 982                 case IIO_SHARED_BY_ALL:
 983                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 984                         break;
 985                 case IIO_SHARED_BY_DIR:
 986                         name = kasprintf(GFP_KERNEL, "%s_%s",
 987                                                 iio_direction[chan->output],
 988                                                 full_postfix);
 989                         break;
 990                 case IIO_SHARED_BY_TYPE:
 991                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 992                                             iio_direction[chan->output],
 993                                             iio_chan_type_name_spec[chan->type],
 994                                             full_postfix);
 995                         break;
 996
 997                 case IIO_SEPARATE:
 998                         if (chan->indexed)
 999                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1000                                                     iio_direction[chan->output],
1001                                                     iio_chan_type_name_spec[chan->type],
1002                                                     chan->channel,
1003                                                     full_postfix);
1004                         else
1005                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1006                                                     iio_direction[chan->output],
1007                                                     iio_chan_type_name_spec[chan->type],
1008                                                     full_postfix);
1009                         break;
1010                 }
1011         }
1012         if (name == NULL) {
1013                 ret = -ENOMEM;
1014                 goto error_free_full_postfix;
1015         }
1016         dev_attr->attr.name = name;
1017
1018         if (readfunc) {
1019                 dev_attr->attr.mode |= S_IRUGO;
1020                 dev_attr->show = readfunc;
1021         }
1022
1023         if (writefunc) {
1024                 dev_attr->attr.mode |= S_IWUSR;
1025                 dev_attr->store = writefunc;
1026         }
1027
1028 error_free_full_postfix:
1029         kfree(full_postfix);
1030
1031         return ret;
1032 }
1033
1034 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1035 {
1036         kfree(dev_attr->attr.name);
1037 }
1038
1039 int __iio_add_chan_devattr(const char *postfix,
1040                            struct iio_chan_spec const *chan,
1041                            ssize_t (*readfunc)(struct device *dev,
1042                                                struct device_attribute *attr,
1043                                                char *buf),
1044                            ssize_t (*writefunc)(struct device *dev,
1045                                                 struct device_attribute *attr,
1046                                                 const char *buf,
1047                                                 size_t len),
1048                            u64 mask,
1049                            enum iio_shared_by shared_by,
1050                            struct device *dev,
1051                            struct list_head *attr_list)
1052 {
1053         int ret;
1054         struct iio_dev_attr *iio_attr, *t;
1055
1056         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1057         if (iio_attr == NULL)
1058                 return -ENOMEM;
1059         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1060                                      postfix, chan,
1061                                      readfunc, writefunc, shared_by);
1062         if (ret)
1063                 goto error_iio_dev_attr_free;
1064         iio_attr->c = chan;
1065         iio_attr->address = mask;
1066         list_for_each_entry(t, attr_list, l)
1067                 if (strcmp(t->dev_attr.attr.name,
1068                            iio_attr->dev_attr.attr.name) == 0) {
1069                         if (shared_by == IIO_SEPARATE)
1070                                 dev_err(dev, "tried to double register : %s\n",
1071                                         t->dev_attr.attr.name);
1072                         ret = -EBUSY;
1073                         goto error_device_attr_deinit;
1074                 }
1075         list_add(&iio_attr->l, attr_list);
1076
1077         return 0;
1078
1079 error_device_attr_deinit:
1080         __iio_device_attr_deinit(&iio_attr->dev_attr);
1081 error_iio_dev_attr_free:
1082         kfree(iio_attr);
1083         return ret;
1084 }
1085
1086 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1087                                          struct iio_chan_spec const *chan,
1088                                          enum iio_shared_by shared_by,
1089                                          const long *infomask)
1090 {
1091         int i, ret, attrcount = 0;
1092
1093         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
1094                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1095                         return -EINVAL;
1096                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1097                                              chan,
1098                                              &iio_read_channel_info,
1099                                              &iio_write_channel_info,
1100                                              i,
1101                                              shared_by,
1102                                              &indio_dev->dev,
1103                                              &indio_dev->channel_attr_list);
1104                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1105                         continue;
1106                 else if (ret < 0)
1107                         return ret;
1108                 attrcount++;
1109         }
1110
1111         return attrcount;
1112 }
1113
1114 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1115                                                struct iio_chan_spec const *chan,
1116                                                enum iio_shared_by shared_by,
1117                                                const long *infomask)
1118 {
1119         int i, ret, attrcount = 0;
1120         char *avail_postfix;
1121
1122         for_each_set_bit(i, infomask, sizeof(infomask) * 8) {
1123                 avail_postfix = kasprintf(GFP_KERNEL,
1124                                           "%s_available",
1125                                           iio_chan_info_postfix[i]);
1126                 if (!avail_postfix)
1127                         return -ENOMEM;
1128
1129                 ret = __iio_add_chan_devattr(avail_postfix,
1130                                              chan,
1131                                              &iio_read_channel_info_avail,
1132                                              NULL,
1133                                              i,
1134                                              shared_by,
1135                                              &indio_dev->dev,
1136                                              &indio_dev->channel_attr_list);
1137                 kfree(avail_postfix);
1138                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1139                         continue;
1140                 else if (ret < 0)
1141                         return ret;
1142                 attrcount++;
1143         }
1144
1145         return attrcount;
1146 }
1147
1148 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1149                                         struct iio_chan_spec const *chan)
1150 {
1151         int ret, attrcount = 0;
1152         const struct iio_chan_spec_ext_info *ext_info;
1153
1154         if (chan->channel < 0)
1155                 return 0;
1156         ret = iio_device_add_info_mask_type(indio_dev, chan,
1157                                             IIO_SEPARATE,
1158                                             &chan->info_mask_separate);
1159         if (ret < 0)
1160                 return ret;
1161         attrcount += ret;
1162
1163         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1164                                                   IIO_SEPARATE,
1165                                                   &chan->
1166                                                   info_mask_separate_available);
1167         if (ret < 0)
1168                 return ret;
1169         attrcount += ret;
1170
1171         ret = iio_device_add_info_mask_type(indio_dev, chan,
1172                                             IIO_SHARED_BY_TYPE,
1173                                             &chan->info_mask_shared_by_type);
1174         if (ret < 0)
1175                 return ret;
1176         attrcount += ret;
1177
1178         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1179                                                   IIO_SHARED_BY_TYPE,
1180                                                   &chan->
1181                                                   info_mask_shared_by_type_available);
1182         if (ret < 0)
1183                 return ret;
1184         attrcount += ret;
1185
1186         ret = iio_device_add_info_mask_type(indio_dev, chan,
1187                                             IIO_SHARED_BY_DIR,
1188                                             &chan->info_mask_shared_by_dir);
1189         if (ret < 0)
1190                 return ret;
1191         attrcount += ret;
1192
1193         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1194                                                   IIO_SHARED_BY_DIR,
1195                                                   &chan->info_mask_shared_by_dir_available);
1196         if (ret < 0)
1197                 return ret;
1198         attrcount += ret;
1199
1200         ret = iio_device_add_info_mask_type(indio_dev, chan,
1201                                             IIO_SHARED_BY_ALL,
1202                                             &chan->info_mask_shared_by_all);
1203         if (ret < 0)
1204                 return ret;
1205         attrcount += ret;
1206
1207         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1208                                                   IIO_SHARED_BY_ALL,
1209                                                   &chan->info_mask_shared_by_all_available);
1210         if (ret < 0)
1211                 return ret;
1212         attrcount += ret;
1213
1214         if (chan->ext_info) {
1215                 unsigned int i = 0;
1216                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1217                         ret = __iio_add_chan_devattr(ext_info->name,
1218                                         chan,
1219                                         ext_info->read ?
1220                                             &iio_read_channel_ext_info : NULL,
1221                                         ext_info->write ?
1222                                             &iio_write_channel_ext_info : NULL,
1223                                         i,
1224                                         ext_info->shared,
1225                                         &indio_dev->dev,
1226                                         &indio_dev->channel_attr_list);
1227                         i++;
1228                         if (ret == -EBUSY && ext_info->shared)
1229                                 continue;
1230
1231                         if (ret)
1232                                 return ret;
1233
1234                         attrcount++;
1235                 }
1236         }
1237
1238         return attrcount;
1239 }
1240
1241 /**
1242  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1243  * @attr_list: List of IIO device attributes
1244  *
1245  * This function frees the memory allocated for each of the IIO device
1246  * attributes in the list.
1247  */
1248 void iio_free_chan_devattr_list(struct list_head *attr_list)
1249 {
1250         struct iio_dev_attr *p, *n;
1251
1252         list_for_each_entry_safe(p, n, attr_list, l) {
1253                 kfree(p->dev_attr.attr.name);
1254                 list_del(&p->l);
1255                 kfree(p);
1256         }
1257 }
1258
1259 static ssize_t iio_show_dev_name(struct device *dev,
1260                                  struct device_attribute *attr,
1261                                  char *buf)
1262 {
1263         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1264         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1265 }
1266
1267 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1268
1269 static ssize_t iio_show_timestamp_clock(struct device *dev,
1270                                         struct device_attribute *attr,
1271                                         char *buf)
1272 {
1273         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1274         const clockid_t clk = iio_device_get_clock(indio_dev);
1275         const char *name;
1276         ssize_t sz;
1277
1278         switch (clk) {
1279         case CLOCK_REALTIME:
1280                 name = "realtime\n";
1281                 sz = sizeof("realtime\n");
1282                 break;
1283         case CLOCK_MONOTONIC:
1284                 name = "monotonic\n";
1285                 sz = sizeof("monotonic\n");
1286                 break;
1287         case CLOCK_MONOTONIC_RAW:
1288                 name = "monotonic_raw\n";
1289                 sz = sizeof("monotonic_raw\n");
1290                 break;
1291         case CLOCK_REALTIME_COARSE:
1292                 name = "realtime_coarse\n";
1293                 sz = sizeof("realtime_coarse\n");
1294                 break;
1295         case CLOCK_MONOTONIC_COARSE:
1296                 name = "monotonic_coarse\n";
1297                 sz = sizeof("monotonic_coarse\n");
1298                 break;
1299         case CLOCK_BOOTTIME:
1300                 name = "boottime\n";
1301                 sz = sizeof("boottime\n");
1302                 break;
1303         case CLOCK_TAI:
1304                 name = "tai\n";
1305                 sz = sizeof("tai\n");
1306                 break;
1307         default:
1308                 BUG();
1309         }
1310
1311         memcpy(buf, name, sz);
1312         return sz;
1313 }
1314
1315 static ssize_t iio_store_timestamp_clock(struct device *dev,
1316                                          struct device_attribute *attr,
1317                                          const char *buf, size_t len)
1318 {
1319         clockid_t clk;
1320         int ret;
1321
1322         if (sysfs_streq(buf, "realtime"))
1323                 clk = CLOCK_REALTIME;
1324         else if (sysfs_streq(buf, "monotonic"))
1325                 clk = CLOCK_MONOTONIC;
1326         else if (sysfs_streq(buf, "monotonic_raw"))
1327                 clk = CLOCK_MONOTONIC_RAW;
1328         else if (sysfs_streq(buf, "realtime_coarse"))
1329                 clk = CLOCK_REALTIME_COARSE;
1330         else if (sysfs_streq(buf, "monotonic_coarse"))
1331                 clk = CLOCK_MONOTONIC_COARSE;
1332         else if (sysfs_streq(buf, "boottime"))
1333                 clk = CLOCK_BOOTTIME;
1334         else if (sysfs_streq(buf, "tai"))
1335                 clk = CLOCK_TAI;
1336         else
1337                 return -EINVAL;
1338
1339         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1340         if (ret)
1341                 return ret;
1342
1343         return len;
1344 }
1345
1346 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1347                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1348
1349 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1350 {
1351         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1352         struct iio_dev_attr *p;
1353         struct attribute **attr, *clk = NULL;
1354
1355         /* First count elements in any existing group */
1356         if (indio_dev->info->attrs) {
1357                 attr = indio_dev->info->attrs->attrs;
1358                 while (*attr++ != NULL)
1359                         attrcount_orig++;
1360         }
1361         attrcount = attrcount_orig;
1362         /*
1363          * New channel registration method - relies on the fact a group does
1364          * not need to be initialized if its name is NULL.
1365          */
1366         if (indio_dev->channels)
1367                 for (i = 0; i < indio_dev->num_channels; i++) {
1368                         const struct iio_chan_spec *chan =
1369                                 &indio_dev->channels[i];
1370
1371                         if (chan->type == IIO_TIMESTAMP)
1372                                 clk = &dev_attr_current_timestamp_clock.attr;
1373
1374                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1375                         if (ret < 0)
1376                                 goto error_clear_attrs;
1377                         attrcount += ret;
1378                 }
1379
1380         if (indio_dev->event_interface)
1381                 clk = &dev_attr_current_timestamp_clock.attr;
1382
1383         if (indio_dev->name)
1384                 attrcount++;
1385         if (clk)
1386                 attrcount++;
1387
1388         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1389                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1390                                                    GFP_KERNEL);
1391         if (indio_dev->chan_attr_group.attrs == NULL) {
1392                 ret = -ENOMEM;
1393                 goto error_clear_attrs;
1394         }
1395         /* Copy across original attributes */
1396         if (indio_dev->info->attrs)
1397                 memcpy(indio_dev->chan_attr_group.attrs,
1398                        indio_dev->info->attrs->attrs,
1399                        sizeof(indio_dev->chan_attr_group.attrs[0])
1400                        *attrcount_orig);
1401         attrn = attrcount_orig;
1402         /* Add all elements from the list. */
1403         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1404                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1405         if (indio_dev->name)
1406                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1407         if (clk)
1408                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1409
1410         indio_dev->groups[indio_dev->groupcounter++] =
1411                 &indio_dev->chan_attr_group;
1412
1413         return 0;
1414
1415 error_clear_attrs:
1416         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1417
1418         return ret;
1419 }
1420
1421 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1422 {
1423
1424         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1425         kfree(indio_dev->chan_attr_group.attrs);
1426         indio_dev->chan_attr_group.attrs = NULL;
1427 }
1428
1429 static void iio_dev_release(struct device *device)
1430 {
1431         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1432         if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1433                 iio_device_unregister_trigger_consumer(indio_dev);
1434         iio_device_unregister_eventset(indio_dev);
1435         iio_device_unregister_sysfs(indio_dev);
1436
1437         iio_buffer_put(indio_dev->buffer);
1438
1439         ida_simple_remove(&iio_ida, indio_dev->id);
1440         kfree(indio_dev);
1441 }
1442
1443 struct device_type iio_device_type = {
1444         .name = "iio_device",
1445         .release = iio_dev_release,
1446 };
1447
1448 /**
1449  * iio_device_alloc() - allocate an iio_dev from a driver
1450  * @sizeof_priv:        Space to allocate for private structure.
1451  **/
1452 struct iio_dev *iio_device_alloc(int sizeof_priv)
1453 {
1454         struct iio_dev *dev;
1455         size_t alloc_size;
1456
1457         alloc_size = sizeof(struct iio_dev);
1458         if (sizeof_priv) {
1459                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1460                 alloc_size += sizeof_priv;
1461         }
1462         /* ensure 32-byte alignment of whole construct ? */
1463         alloc_size += IIO_ALIGN - 1;
1464
1465         dev = kzalloc(alloc_size, GFP_KERNEL);
1466
1467         if (dev) {
1468                 dev->dev.groups = dev->groups;
1469                 dev->dev.type = &iio_device_type;
1470                 dev->dev.bus = &iio_bus_type;
1471                 device_initialize(&dev->dev);
1472                 dev_set_drvdata(&dev->dev, (void *)dev);
1473                 mutex_init(&dev->mlock);
1474                 mutex_init(&dev->info_exist_lock);
1475                 INIT_LIST_HEAD(&dev->channel_attr_list);
1476
1477                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1478                 if (dev->id < 0) {
1479                         /* cannot use a dev_err as the name isn't available */
1480                         pr_err("failed to get device id\n");
1481                         kfree(dev);
1482                         return NULL;
1483                 }
1484                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1485                 INIT_LIST_HEAD(&dev->buffer_list);
1486         }
1487
1488         return dev;
1489 }
1490 EXPORT_SYMBOL(iio_device_alloc);
1491
1492 /**
1493  * iio_device_free() - free an iio_dev from a driver
1494  * @dev:                the iio_dev associated with the device
1495  **/
1496 void iio_device_free(struct iio_dev *dev)
1497 {
1498         if (dev)
1499                 put_device(&dev->dev);
1500 }
1501 EXPORT_SYMBOL(iio_device_free);
1502
1503 static void devm_iio_device_release(struct device *dev, void *res)
1504 {
1505         iio_device_free(*(struct iio_dev **)res);
1506 }
1507
1508 int devm_iio_device_match(struct device *dev, void *res, void *data)
1509 {
1510         struct iio_dev **r = res;
1511         if (!r || !*r) {
1512                 WARN_ON(!r || !*r);
1513                 return 0;
1514         }
1515         return *r == data;
1516 }
1517 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1518
1519 /**
1520  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1521  * @dev:                Device to allocate iio_dev for
1522  * @sizeof_priv:        Space to allocate for private structure.
1523  *
1524  * Managed iio_device_alloc. iio_dev allocated with this function is
1525  * automatically freed on driver detach.
1526  *
1527  * If an iio_dev allocated with this function needs to be freed separately,
1528  * devm_iio_device_free() must be used.
1529  *
1530  * RETURNS:
1531  * Pointer to allocated iio_dev on success, NULL on failure.
1532  */
1533 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1534 {
1535         struct iio_dev **ptr, *iio_dev;
1536
1537         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1538                            GFP_KERNEL);
1539         if (!ptr)
1540                 return NULL;
1541
1542         iio_dev = iio_device_alloc(sizeof_priv);
1543         if (iio_dev) {
1544                 *ptr = iio_dev;
1545                 devres_add(dev, ptr);
1546         } else {
1547                 devres_free(ptr);
1548         }
1549
1550         return iio_dev;
1551 }
1552 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1553
1554 /**
1555  * devm_iio_device_free - Resource-managed iio_device_free()
1556  * @dev:                Device this iio_dev belongs to
1557  * @iio_dev:            the iio_dev associated with the device
1558  *
1559  * Free iio_dev allocated with devm_iio_device_alloc().
1560  */
1561 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1562 {
1563         int rc;
1564
1565         rc = devres_release(dev, devm_iio_device_release,
1566                             devm_iio_device_match, iio_dev);
1567         WARN_ON(rc);
1568 }
1569 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1570
1571 /**
1572  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1573  * @inode:      Inode structure for identifying the device in the file system
1574  * @filp:       File structure for iio device used to keep and later access
1575  *              private data
1576  *
1577  * Return: 0 on success or -EBUSY if the device is already opened
1578  **/
1579 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1580 {
1581         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1582                                                 struct iio_dev, chrdev);
1583
1584         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1585                 return -EBUSY;
1586
1587         iio_device_get(indio_dev);
1588
1589         filp->private_data = indio_dev;
1590
1591         return 0;
1592 }
1593
1594 /**
1595  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1596  * @inode:      Inode structure pointer for the char device
1597  * @filp:       File structure pointer for the char device
1598  *
1599  * Return: 0 for successful release
1600  */
1601 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1602 {
1603         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1604                                                 struct iio_dev, chrdev);
1605         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1606         iio_device_put(indio_dev);
1607
1608         return 0;
1609 }
1610
1611 /* Somewhat of a cross file organization violation - ioctls here are actually
1612  * event related */
1613 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1614 {
1615         struct iio_dev *indio_dev = filp->private_data;
1616         int __user *ip = (int __user *)arg;
1617         int fd;
1618
1619         if (!indio_dev->info)
1620                 return -ENODEV;
1621
1622         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1623                 fd = iio_event_getfd(indio_dev);
1624                 if (fd < 0)
1625                         return fd;
1626                 if (copy_to_user(ip, &fd, sizeof(fd)))
1627                         return -EFAULT;
1628                 return 0;
1629         }
1630         return -EINVAL;
1631 }
1632
1633 static const struct file_operations iio_buffer_fileops = {
1634         .read = iio_buffer_read_first_n_outer_addr,
1635         .release = iio_chrdev_release,
1636         .open = iio_chrdev_open,
1637         .poll = iio_buffer_poll_addr,
1638         .owner = THIS_MODULE,
1639         .llseek = noop_llseek,
1640         .unlocked_ioctl = iio_ioctl,
1641         .compat_ioctl = iio_ioctl,
1642 };
1643
1644 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1645 {
1646         int i, j;
1647         const struct iio_chan_spec *channels = indio_dev->channels;
1648
1649         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1650                 return 0;
1651
1652         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1653                 if (channels[i].scan_index < 0)
1654                         continue;
1655                 for (j = i + 1; j < indio_dev->num_channels; j++)
1656                         if (channels[i].scan_index == channels[j].scan_index) {
1657                                 dev_err(&indio_dev->dev,
1658                                         "Duplicate scan index %d\n",
1659                                         channels[i].scan_index);
1660                                 return -EINVAL;
1661                         }
1662         }
1663
1664         return 0;
1665 }
1666
1667 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1668
1669 /**
1670  * iio_device_register() - register a device with the IIO subsystem
1671  * @indio_dev:          Device structure filled by the device driver
1672  **/
1673 int iio_device_register(struct iio_dev *indio_dev)
1674 {
1675         int ret;
1676
1677         /* If the calling driver did not initialize of_node, do it here */
1678         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1679                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1680
1681         ret = iio_check_unique_scan_index(indio_dev);
1682         if (ret < 0)
1683                 return ret;
1684
1685         /* configure elements for the chrdev */
1686         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1687
1688         ret = iio_device_register_debugfs(indio_dev);
1689         if (ret) {
1690                 dev_err(indio_dev->dev.parent,
1691                         "Failed to register debugfs interfaces\n");
1692                 return ret;
1693         }
1694
1695         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1696         if (ret) {
1697                 dev_err(indio_dev->dev.parent,
1698                         "Failed to create buffer sysfs interfaces\n");
1699                 goto error_unreg_debugfs;
1700         }
1701
1702         ret = iio_device_register_sysfs(indio_dev);
1703         if (ret) {
1704                 dev_err(indio_dev->dev.parent,
1705                         "Failed to register sysfs interfaces\n");
1706                 goto error_buffer_free_sysfs;
1707         }
1708         ret = iio_device_register_eventset(indio_dev);
1709         if (ret) {
1710                 dev_err(indio_dev->dev.parent,
1711                         "Failed to register event set\n");
1712                 goto error_free_sysfs;
1713         }
1714         if (indio_dev->modes & (INDIO_BUFFER_TRIGGERED | INDIO_EVENT_TRIGGERED))
1715                 iio_device_register_trigger_consumer(indio_dev);
1716
1717         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1718                 indio_dev->setup_ops == NULL)
1719                 indio_dev->setup_ops = &noop_ring_setup_ops;
1720
1721         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1722         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1723         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1724         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1725         if (ret < 0)
1726                 goto error_unreg_eventset;
1727
1728         ret = device_add(&indio_dev->dev);
1729         if (ret < 0)
1730                 goto error_cdev_del;
1731
1732         return 0;
1733 error_cdev_del:
1734         cdev_del(&indio_dev->chrdev);
1735 error_unreg_eventset:
1736         iio_device_unregister_eventset(indio_dev);
1737 error_free_sysfs:
1738         iio_device_unregister_sysfs(indio_dev);
1739 error_buffer_free_sysfs:
1740         iio_buffer_free_sysfs_and_mask(indio_dev);
1741 error_unreg_debugfs:
1742         iio_device_unregister_debugfs(indio_dev);
1743         return ret;
1744 }
1745 EXPORT_SYMBOL(iio_device_register);
1746
1747 /**
1748  * iio_device_unregister() - unregister a device from the IIO subsystem
1749  * @indio_dev:          Device structure representing the device.
1750  **/
1751 void iio_device_unregister(struct iio_dev *indio_dev)
1752 {
1753         mutex_lock(&indio_dev->info_exist_lock);
1754
1755         device_del(&indio_dev->dev);
1756
1757         if (indio_dev->chrdev.dev)
1758                 cdev_del(&indio_dev->chrdev);
1759         iio_device_unregister_debugfs(indio_dev);
1760
1761         iio_disable_all_buffers(indio_dev);
1762
1763         indio_dev->info = NULL;
1764
1765         iio_device_wakeup_eventset(indio_dev);
1766         iio_buffer_wakeup_poll(indio_dev);
1767
1768         mutex_unlock(&indio_dev->info_exist_lock);
1769
1770         iio_buffer_free_sysfs_and_mask(indio_dev);
1771 }
1772 EXPORT_SYMBOL(iio_device_unregister);
1773
1774 static void devm_iio_device_unreg(struct device *dev, void *res)
1775 {
1776         iio_device_unregister(*(struct iio_dev **)res);
1777 }
1778
1779 /**
1780  * devm_iio_device_register - Resource-managed iio_device_register()
1781  * @dev:        Device to allocate iio_dev for
1782  * @indio_dev:  Device structure filled by the device driver
1783  *
1784  * Managed iio_device_register.  The IIO device registered with this
1785  * function is automatically unregistered on driver detach. This function
1786  * calls iio_device_register() internally. Refer to that function for more
1787  * information.
1788  *
1789  * If an iio_dev registered with this function needs to be unregistered
1790  * separately, devm_iio_device_unregister() must be used.
1791  *
1792  * RETURNS:
1793  * 0 on success, negative error number on failure.
1794  */
1795 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1796 {
1797         struct iio_dev **ptr;
1798         int ret;
1799
1800         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1801         if (!ptr)
1802                 return -ENOMEM;
1803
1804         *ptr = indio_dev;
1805         ret = iio_device_register(indio_dev);
1806         if (!ret)
1807                 devres_add(dev, ptr);
1808         else
1809                 devres_free(ptr);
1810
1811         return ret;
1812 }
1813 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1814
1815 /**
1816  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1817  * @dev:        Device this iio_dev belongs to
1818  * @indio_dev:  the iio_dev associated with the device
1819  *
1820  * Unregister iio_dev registered with devm_iio_device_register().
1821  */
1822 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1823 {
1824         int rc;
1825
1826         rc = devres_release(dev, devm_iio_device_unreg,
1827                             devm_iio_device_match, indio_dev);
1828         WARN_ON(rc);
1829 }
1830 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1831
1832 /**
1833  * iio_device_claim_direct_mode - Keep device in direct mode
1834  * @indio_dev:  the iio_dev associated with the device
1835  *
1836  * If the device is in direct mode it is guaranteed to stay
1837  * that way until iio_device_release_direct_mode() is called.
1838  *
1839  * Use with iio_device_release_direct_mode()
1840  *
1841  * Returns: 0 on success, -EBUSY on failure
1842  */
1843 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1844 {
1845         mutex_lock(&indio_dev->mlock);
1846
1847         if (iio_buffer_enabled(indio_dev)) {
1848                 mutex_unlock(&indio_dev->mlock);
1849                 return -EBUSY;
1850         }
1851         return 0;
1852 }
1853 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1854
1855 /**
1856  * iio_device_release_direct_mode - releases claim on direct mode
1857  * @indio_dev:  the iio_dev associated with the device
1858  *
1859  * Release the claim. Device is no longer guaranteed to stay
1860  * in direct mode.
1861  *
1862  * Use with iio_device_claim_direct_mode()
1863  */
1864 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1865 {
1866         mutex_unlock(&indio_dev->mlock);
1867 }
1868 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1869
1870 subsys_initcall(iio_init);
1871 module_exit(iio_exit);
1872
1873 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1874 MODULE_DESCRIPTION("Industrial I/O core");
1875 MODULE_LICENSE("GPL");