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