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