drivers/iio/industrialio-core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* The industrial I/O core
   3  *
   4  * Copyright (c) 2008 Jonathan Cameron
   5  *
   6  * Based on elements of hwmon and input subsystems.
   7  */
   8
   9 #define pr_fmt(fmt) "iio-core: " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/idr.h>
  14 #include <linux/kdev_t.h>
  15 #include <linux/err.h>
  16 #include <linux/device.h>
  17 #include <linux/fs.h>
  18 #include <linux/poll.h>
  19 #include <linux/property.h>
  20 #include <linux/sched.h>
  21 #include <linux/wait.h>
  22 #include <linux/cdev.h>
  23 #include <linux/slab.h>
  24 #include <linux/anon_inodes.h>
  25 #include <linux/debugfs.h>
  26 #include <linux/mutex.h>
  27 #include <linux/iio/iio.h>
  28 #include "iio_core.h"
  29 #include "iio_core_trigger.h"
  30 #include <linux/iio/sysfs.h>
  31 #include <linux/iio/events.h>
  32 #include <linux/iio/buffer.h>
  33 #include <linux/iio/buffer_impl.h>
  34
  35 /* IDA to assign each registered device a unique id */
  36 static DEFINE_IDA(iio_ida);
  37
  38 static dev_t iio_devt;
  39
  40 #define IIO_DEV_MAX 256
  41 struct bus_type iio_bus_type = {
  42         .name = "iio",
  43 };
  44 EXPORT_SYMBOL(iio_bus_type);
  45
  46 static struct dentry *iio_debugfs_dentry;
  47
  48 static const char * const iio_direction[] = {
  49         [0] = "in",
  50         [1] = "out",
  51 };
  52
  53 static const char * const iio_chan_type_name_spec[] = {
  54         [IIO_VOLTAGE] = "voltage",
  55         [IIO_CURRENT] = "current",
  56         [IIO_POWER] = "power",
  57         [IIO_ACCEL] = "accel",
  58         [IIO_ANGL_VEL] = "anglvel",
  59         [IIO_MAGN] = "magn",
  60         [IIO_LIGHT] = "illuminance",
  61         [IIO_INTENSITY] = "intensity",
  62         [IIO_PROXIMITY] = "proximity",
  63         [IIO_TEMP] = "temp",
  64         [IIO_INCLI] = "incli",
  65         [IIO_ROT] = "rot",
  66         [IIO_ANGL] = "angl",
  67         [IIO_TIMESTAMP] = "timestamp",
  68         [IIO_CAPACITANCE] = "capacitance",
  69         [IIO_ALTVOLTAGE] = "altvoltage",
  70         [IIO_CCT] = "cct",
  71         [IIO_PRESSURE] = "pressure",
  72         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  73         [IIO_ACTIVITY] = "activity",
  74         [IIO_STEPS] = "steps",
  75         [IIO_ENERGY] = "energy",
  76         [IIO_DISTANCE] = "distance",
  77         [IIO_VELOCITY] = "velocity",
  78         [IIO_CONCENTRATION] = "concentration",
  79         [IIO_RESISTANCE] = "resistance",
  80         [IIO_PH] = "ph",
  81         [IIO_UVINDEX] = "uvindex",
  82         [IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
  83         [IIO_COUNT] = "count",
  84         [IIO_INDEX] = "index",
  85         [IIO_GRAVITY]  = "gravity",
  86         [IIO_POSITIONRELATIVE]  = "positionrelative",
  87         [IIO_PHASE] = "phase",
  88         [IIO_MASSCONCENTRATION] = "massconcentration",
  89 };
  90
  91 static const char * const iio_modifier_names[] = {
  92         [IIO_MOD_X] = "x",
  93         [IIO_MOD_Y] = "y",
  94         [IIO_MOD_Z] = "z",
  95         [IIO_MOD_X_AND_Y] = "x&y",
  96         [IIO_MOD_X_AND_Z] = "x&z",
  97         [IIO_MOD_Y_AND_Z] = "y&z",
  98         [IIO_MOD_X_AND_Y_AND_Z] = "x&y&z",
  99         [IIO_MOD_X_OR_Y] = "x|y",
 100         [IIO_MOD_X_OR_Z] = "x|z",
 101         [IIO_MOD_Y_OR_Z] = "y|z",
 102         [IIO_MOD_X_OR_Y_OR_Z] = "x|y|z",
 103         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
 104         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
 105         [IIO_MOD_LIGHT_BOTH] = "both",
 106         [IIO_MOD_LIGHT_IR] = "ir",
 107         [IIO_MOD_LIGHT_CLEAR] = "clear",
 108         [IIO_MOD_LIGHT_RED] = "red",
 109         [IIO_MOD_LIGHT_GREEN] = "green",
 110         [IIO_MOD_LIGHT_BLUE] = "blue",
 111         [IIO_MOD_LIGHT_UV] = "uv",
 112         [IIO_MOD_LIGHT_DUV] = "duv",
 113         [IIO_MOD_QUATERNION] = "quaternion",
 114         [IIO_MOD_TEMP_AMBIENT] = "ambient",
 115         [IIO_MOD_TEMP_OBJECT] = "object",
 116         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
 117         [IIO_MOD_NORTH_TRUE] = "from_north_true",
 118         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 119         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
 120         [IIO_MOD_RUNNING] = "running",
 121         [IIO_MOD_JOGGING] = "jogging",
 122         [IIO_MOD_WALKING] = "walking",
 123         [IIO_MOD_STILL] = "still",
 124         [IIO_MOD_ROOT_SUM_SQUARED_X_Y_Z] = "sqrt(x^2+y^2+z^2)",
 125         [IIO_MOD_I] = "i",
 126         [IIO_MOD_Q] = "q",
 127         [IIO_MOD_CO2] = "co2",
 128         [IIO_MOD_VOC] = "voc",
 129         [IIO_MOD_PM1] = "pm1",
 130         [IIO_MOD_PM2P5] = "pm2p5",
 131         [IIO_MOD_PM4] = "pm4",
 132         [IIO_MOD_PM10] = "pm10",
 133 };
 134
 135 /* relies on pairs of these shared then separate */
 136 static const char * const iio_chan_info_postfix[] = {
 137         [IIO_CHAN_INFO_RAW] = "raw",
 138         [IIO_CHAN_INFO_PROCESSED] = "input",
 139         [IIO_CHAN_INFO_SCALE] = "scale",
 140         [IIO_CHAN_INFO_OFFSET] = "offset",
 141         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 142         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 143         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 144         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 145         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 146         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 147         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 148         = "filter_low_pass_3db_frequency",
 149         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 150         = "filter_high_pass_3db_frequency",
 151         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 152         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 153         [IIO_CHAN_INFO_PHASE] = "phase",
 154         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 155         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 156         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 157         [IIO_CHAN_INFO_ENABLE] = "en",
 158         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 159         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 160         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 161         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 162         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 163         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 164         [IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
 165 };
 166
 167 /**
 168  * iio_find_channel_from_si() - get channel from its scan index
 169  * @indio_dev:          device
 170  * @si:                 scan index to match
 171  */
 172 const struct iio_chan_spec
 173 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 174 {
 175         int i;
 176
 177         for (i = 0; i < indio_dev->num_channels; i++)
 178                 if (indio_dev->channels[i].scan_index == si)
 179                         return &indio_dev->channels[i];
 180         return NULL;
 181 }
 182
 183 /* This turns up an awful lot */
 184 ssize_t iio_read_const_attr(struct device *dev,
 185                             struct device_attribute *attr,
 186                             char *buf)
 187 {
 188         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 189 }
 190 EXPORT_SYMBOL(iio_read_const_attr);
 191
 192 static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 193 {
 194         int ret;
 195         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 196
 197         ret = mutex_lock_interruptible(&indio_dev->mlock);
 198         if (ret)
 199                 return ret;
 200         if ((ev_int && iio_event_enabled(ev_int)) ||
 201             iio_buffer_enabled(indio_dev)) {
 202                 mutex_unlock(&indio_dev->mlock);
 203                 return -EBUSY;
 204         }
 205         indio_dev->clock_id = clock_id;
 206         mutex_unlock(&indio_dev->mlock);
 207
 208         return 0;
 209 }
 210
 211 /**
 212  * iio_get_time_ns() - utility function to get a time stamp for events etc
 213  * @indio_dev: device
 214  */
 215 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 216 {
 217         struct timespec64 tp;
 218
 219         switch (iio_device_get_clock(indio_dev)) {
 220         case CLOCK_REALTIME:
 221                 return ktime_get_real_ns();
 222         case CLOCK_MONOTONIC:
 223                 return ktime_get_ns();
 224         case CLOCK_MONOTONIC_RAW:
 225                 return ktime_get_raw_ns();
 226         case CLOCK_REALTIME_COARSE:
 227                 return ktime_to_ns(ktime_get_coarse_real());
 228         case CLOCK_MONOTONIC_COARSE:
 229                 ktime_get_coarse_ts64(&tp);
 230                 return timespec64_to_ns(&tp);
 231         case CLOCK_BOOTTIME:
 232                 return ktime_get_boottime_ns();
 233         case CLOCK_TAI:
 234                 return ktime_get_clocktai_ns();
 235         default:
 236                 BUG();
 237         }
 238 }
 239 EXPORT_SYMBOL(iio_get_time_ns);
 240
 241 /**
 242  * iio_get_time_res() - utility function to get time stamp clock resolution in
 243  *                      nano seconds.
 244  * @indio_dev: device
 245  */
 246 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 247 {
 248         switch (iio_device_get_clock(indio_dev)) {
 249         case CLOCK_REALTIME:
 250         case CLOCK_MONOTONIC:
 251         case CLOCK_MONOTONIC_RAW:
 252         case CLOCK_BOOTTIME:
 253         case CLOCK_TAI:
 254                 return hrtimer_resolution;
 255         case CLOCK_REALTIME_COARSE:
 256         case CLOCK_MONOTONIC_COARSE:
 257                 return LOW_RES_NSEC;
 258         default:
 259                 BUG();
 260         }
 261 }
 262 EXPORT_SYMBOL(iio_get_time_res);
 263
 264 static int __init iio_init(void)
 265 {
 266         int ret;
 267
 268         /* Register sysfs bus */
 269         ret  = bus_register(&iio_bus_type);
 270         if (ret < 0) {
 271                 pr_err("could not register bus type\n");
 272                 goto error_nothing;
 273         }
 274
 275         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 276         if (ret < 0) {
 277                 pr_err("failed to allocate char dev region\n");
 278                 goto error_unregister_bus_type;
 279         }
 280
 281         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 282
 283         return 0;
 284
 285 error_unregister_bus_type:
 286         bus_unregister(&iio_bus_type);
 287 error_nothing:
 288         return ret;
 289 }
 290
 291 static void __exit iio_exit(void)
 292 {
 293         if (iio_devt)
 294                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 295         bus_unregister(&iio_bus_type);
 296         debugfs_remove(iio_debugfs_dentry);
 297 }
 298
 299 #if defined(CONFIG_DEBUG_FS)
 300 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 301                               size_t count, loff_t *ppos)
 302 {
 303         struct iio_dev *indio_dev = file->private_data;
 304         unsigned val = 0;
 305         int ret;
 306
 307         if (*ppos > 0)
 308                 return simple_read_from_buffer(userbuf, count, ppos,
 309                                                indio_dev->read_buf,
 310                                                indio_dev->read_buf_len);
 311
 312         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 313                                                   indio_dev->cached_reg_addr,
 314                                                   0, &val);
 315         if (ret) {
 316                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 317                 return ret;
 318         }
 319
 320         indio_dev->read_buf_len = snprintf(indio_dev->read_buf,
 321                                            sizeof(indio_dev->read_buf),
 322                                            "0x%X\n", val);
 323
 324         return simple_read_from_buffer(userbuf, count, ppos,
 325                                        indio_dev->read_buf,
 326                                        indio_dev->read_buf_len);
 327 }
 328
 329 static ssize_t iio_debugfs_write_reg(struct file *file,
 330                      const char __user *userbuf, size_t count, loff_t *ppos)
 331 {
 332         struct iio_dev *indio_dev = file->private_data;
 333         unsigned reg, val;
 334         char buf[80];
 335         int ret;
 336
 337         count = min_t(size_t, count, (sizeof(buf)-1));
 338         if (copy_from_user(buf, userbuf, count))
 339                 return -EFAULT;
 340
 341         buf[count] = 0;
 342
 343         ret = sscanf(buf, "%i %i", &reg, &val);
 344
 345         switch (ret) {
 346         case 1:
 347                 indio_dev->cached_reg_addr = reg;
 348                 break;
 349         case 2:
 350                 indio_dev->cached_reg_addr = reg;
 351                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 352                                                           val, NULL);
 353                 if (ret) {
 354                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 355                                 __func__);
 356                         return ret;
 357                 }
 358                 break;
 359         default:
 360                 return -EINVAL;
 361         }
 362
 363         return count;
 364 }
 365
 366 static const struct file_operations iio_debugfs_reg_fops = {
 367         .open = simple_open,
 368         .read = iio_debugfs_read_reg,
 369         .write = iio_debugfs_write_reg,
 370 };
 371
 372 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 373 {
 374         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 375 }
 376
 377 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 378 {
 379         if (indio_dev->info->debugfs_reg_access == NULL)
 380                 return;
 381
 382         if (!iio_debugfs_dentry)
 383                 return;
 384
 385         indio_dev->debugfs_dentry =
 386                 debugfs_create_dir(dev_name(&indio_dev->dev),
 387                                    iio_debugfs_dentry);
 388
 389         debugfs_create_file("direct_reg_access", 0644,
 390                             indio_dev->debugfs_dentry, indio_dev,
 391                             &iio_debugfs_reg_fops);
 392 }
 393 #else
 394 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 395 {
 396 }
 397
 398 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 399 {
 400 }
 401 #endif /* CONFIG_DEBUG_FS */
 402
 403 static ssize_t iio_read_channel_ext_info(struct device *dev,
 404                                      struct device_attribute *attr,
 405                                      char *buf)
 406 {
 407         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 408         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 409         const struct iio_chan_spec_ext_info *ext_info;
 410
 411         ext_info = &this_attr->c->ext_info[this_attr->address];
 412
 413         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 414 }
 415
 416 static ssize_t iio_write_channel_ext_info(struct device *dev,
 417                                      struct device_attribute *attr,
 418                                      const char *buf,
 419                                          size_t len)
 420 {
 421         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 422         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 423         const struct iio_chan_spec_ext_info *ext_info;
 424
 425         ext_info = &this_attr->c->ext_info[this_attr->address];
 426
 427         return ext_info->write(indio_dev, ext_info->private,
 428                                this_attr->c, buf, len);
 429 }
 430
 431 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 432         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 433 {
 434         const struct iio_enum *e = (const struct iio_enum *)priv;
 435         unsigned int i;
 436         size_t len = 0;
 437
 438         if (!e->num_items)
 439                 return 0;
 440
 441         for (i = 0; i < e->num_items; ++i)
 442                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 443
 444         /* replace last space with a newline */
 445         buf[len - 1] = '\n';
 446
 447         return len;
 448 }
 449 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 450
 451 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 452         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 453 {
 454         const struct iio_enum *e = (const struct iio_enum *)priv;
 455         int i;
 456
 457         if (!e->get)
 458                 return -EINVAL;
 459
 460         i = e->get(indio_dev, chan);
 461         if (i < 0)
 462                 return i;
 463         else if (i >= e->num_items)
 464                 return -EINVAL;
 465
 466         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 467 }
 468 EXPORT_SYMBOL_GPL(iio_enum_read);
 469
 470 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 471         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 472         size_t len)
 473 {
 474         const struct iio_enum *e = (const struct iio_enum *)priv;
 475         int ret;
 476
 477         if (!e->set)
 478                 return -EINVAL;
 479
 480         ret = __sysfs_match_string(e->items, e->num_items, buf);
 481         if (ret < 0)
 482                 return ret;
 483
 484         ret = e->set(indio_dev, chan, ret);
 485         return ret ? ret : len;
 486 }
 487 EXPORT_SYMBOL_GPL(iio_enum_write);
 488
 489 static const struct iio_mount_matrix iio_mount_idmatrix = {
 490         .rotation = {
 491                 "1", "0", "0",
 492                 "0", "1", "0",
 493                 "0", "0", "1"
 494         }
 495 };
 496
 497 static int iio_setup_mount_idmatrix(const struct device *dev,
 498                                     struct iio_mount_matrix *matrix)
 499 {
 500         *matrix = iio_mount_idmatrix;
 501         dev_info(dev, "mounting matrix not found: using identity...\n");
 502         return 0;
 503 }
 504
 505 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 506                               const struct iio_chan_spec *chan, char *buf)
 507 {
 508         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 509                                               priv)(indio_dev, chan);
 510
 511         if (IS_ERR(mtx))
 512                 return PTR_ERR(mtx);
 513
 514         if (!mtx)
 515                 mtx = &iio_mount_idmatrix;
 516
 517         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 518                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 519                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 520                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 521 }
 522 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 523
 524 /**
 525  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
 526  *                           device "mount-matrix" property
 527  * @dev:        device the mounting matrix property is assigned to
 528  * @propname:   device specific mounting matrix property name
 529  * @matrix:     where to store retrieved matrix
 530  *
 531  * If device is assigned no mounting matrix property, a default 3x3 identity
 532  * matrix will be filled in.
 533  *
 534  * Return: 0 if success, or a negative error code on failure.
 535  */
 536 int iio_read_mount_matrix(struct device *dev, const char *propname,
 537                           struct iio_mount_matrix *matrix)
 538 {
 539         size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
 540         int err;
 541
 542         err = device_property_read_string_array(dev, propname,
 543                                                 matrix->rotation, len);
 544         if (err == len)
 545                 return 0;
 546
 547         if (err >= 0)
 548                 /* Invalid number of matrix entries. */
 549                 return -EINVAL;
 550
 551         if (err != -EINVAL)
 552                 /* Invalid matrix declaration format. */
 553                 return err;
 554
 555         /* Matrix was not declared at all: fallback to identity. */
 556         return iio_setup_mount_idmatrix(dev, matrix);
 557 }
 558 EXPORT_SYMBOL(iio_read_mount_matrix);
 559
 560 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 561                                   int size, const int *vals)
 562 {
 563         unsigned long long tmp;
 564         int tmp0, tmp1;
 565         bool scale_db = false;
 566
 567         switch (type) {
 568         case IIO_VAL_INT:
 569                 return snprintf(buf, len, "%d", vals[0]);
 570         case IIO_VAL_INT_PLUS_MICRO_DB:
 571                 scale_db = true;
 572                 /* fall through */
 573         case IIO_VAL_INT_PLUS_MICRO:
 574                 if (vals[1] < 0)
 575                         return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 576                                         -vals[1], scale_db ? " dB" : "");
 577                 else
 578                         return snprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 579                                         scale_db ? " dB" : "");
 580         case IIO_VAL_INT_PLUS_NANO:
 581                 if (vals[1] < 0)
 582                         return snprintf(buf, len, "-%d.%09u", abs(vals[0]),
 583                                         -vals[1]);
 584                 else
 585                         return snprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 586         case IIO_VAL_FRACTIONAL:
 587                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 588                 tmp1 = vals[1];
 589                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 590                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 591         case IIO_VAL_FRACTIONAL_LOG2:
 592                 tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 593                 tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 594                 return snprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 595         case IIO_VAL_INT_MULTIPLE:
 596         {
 597                 int i;
 598                 int l = 0;
 599
 600                 for (i = 0; i < size; ++i) {
 601                         l += snprintf(&buf[l], len - l, "%d ", vals[i]);
 602                         if (l >= len)
 603                                 break;
 604                 }
 605                 return l;
 606         }
 607         case IIO_VAL_CHAR:
 608                 return snprintf(buf, len, "%c", (char)vals[0]);
 609         default:
 610                 return 0;
 611         }
 612 }
 613
 614 /**
 615  * iio_format_value() - Formats a IIO value into its string representation
 616  * @buf:        The buffer to which the formatted value gets written
 617  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 618  * @type:       One of the IIO_VAL_* constants. This decides how the val
 619  *              and val2 parameters are formatted.
 620  * @size:       Number of IIO value entries contained in vals
 621  * @vals:       Pointer to the values, exact meaning depends on the
 622  *              type parameter.
 623  *
 624  * Return: 0 by default, a negative number on failure or the
 625  *         total number of characters written for a type that belongs
 626  *         to the IIO_VAL_* constant.
 627  */
 628 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 629 {
 630         ssize_t len;
 631
 632         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 633         if (len >= PAGE_SIZE - 1)
 634                 return -EFBIG;
 635
 636         return len + sprintf(buf + len, "\n");
 637 }
 638 EXPORT_SYMBOL_GPL(iio_format_value);
 639
 640 static ssize_t iio_read_channel_info(struct device *dev,
 641                                      struct device_attribute *attr,
 642                                      char *buf)
 643 {
 644         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 645         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 646         int vals[INDIO_MAX_RAW_ELEMENTS];
 647         int ret;
 648         int val_len = 2;
 649
 650         if (indio_dev->info->read_raw_multi)
 651                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 652                                                         INDIO_MAX_RAW_ELEMENTS,
 653                                                         vals, &val_len,
 654                                                         this_attr->address);
 655         else
 656                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 657                                     &vals[0], &vals[1], this_attr->address);
 658
 659         if (ret < 0)
 660                 return ret;
 661
 662         return iio_format_value(buf, ret, val_len, vals);
 663 }
 664
 665 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 666                                      int type, int length)
 667 {
 668         int i;
 669         ssize_t len = 0;
 670
 671         switch (type) {
 672         case IIO_VAL_INT:
 673                 for (i = 0; i < length; i++) {
 674                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 675                                                   type, 1, &vals[i]);
 676                         if (len >= PAGE_SIZE)
 677                                 return -EFBIG;
 678                         if (i < length - 1)
 679                                 len += snprintf(buf + len, PAGE_SIZE - len,
 680                                                 " ");
 681                         else
 682                                 len += snprintf(buf + len, PAGE_SIZE - len,
 683                                                 "\n");
 684                         if (len >= PAGE_SIZE)
 685                                 return -EFBIG;
 686                 }
 687                 break;
 688         default:
 689                 for (i = 0; i < length / 2; i++) {
 690                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 691                                                   type, 2, &vals[i * 2]);
 692                         if (len >= PAGE_SIZE)
 693                                 return -EFBIG;
 694                         if (i < length / 2 - 1)
 695                                 len += snprintf(buf + len, PAGE_SIZE - len,
 696                                                 " ");
 697                         else
 698                                 len += snprintf(buf + len, PAGE_SIZE - len,
 699                                                 "\n");
 700                         if (len >= PAGE_SIZE)
 701                                 return -EFBIG;
 702                 }
 703         }
 704
 705         return len;
 706 }
 707
 708 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 709 {
 710         int i;
 711         ssize_t len;
 712
 713         len = snprintf(buf, PAGE_SIZE, "[");
 714         switch (type) {
 715         case IIO_VAL_INT:
 716                 for (i = 0; i < 3; i++) {
 717                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 718                                                   type, 1, &vals[i]);
 719                         if (len >= PAGE_SIZE)
 720                                 return -EFBIG;
 721                         if (i < 2)
 722                                 len += snprintf(buf + len, PAGE_SIZE - len,
 723                                                 " ");
 724                         else
 725                                 len += snprintf(buf + len, PAGE_SIZE - len,
 726                                                 "]\n");
 727                         if (len >= PAGE_SIZE)
 728                                 return -EFBIG;
 729                 }
 730                 break;
 731         default:
 732                 for (i = 0; i < 3; i++) {
 733                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 734                                                   type, 2, &vals[i * 2]);
 735                         if (len >= PAGE_SIZE)
 736                                 return -EFBIG;
 737                         if (i < 2)
 738                                 len += snprintf(buf + len, PAGE_SIZE - len,
 739                                                 " ");
 740                         else
 741                                 len += snprintf(buf + len, PAGE_SIZE - len,
 742                                                 "]\n");
 743                         if (len >= PAGE_SIZE)
 744                                 return -EFBIG;
 745                 }
 746         }
 747
 748         return len;
 749 }
 750
 751 static ssize_t iio_read_channel_info_avail(struct device *dev,
 752                                            struct device_attribute *attr,
 753                                            char *buf)
 754 {
 755         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 756         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 757         const int *vals;
 758         int ret;
 759         int length;
 760         int type;
 761
 762         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 763                                           &vals, &type, &length,
 764                                           this_attr->address);
 765
 766         if (ret < 0)
 767                 return ret;
 768         switch (ret) {
 769         case IIO_AVAIL_LIST:
 770                 return iio_format_avail_list(buf, vals, type, length);
 771         case IIO_AVAIL_RANGE:
 772                 return iio_format_avail_range(buf, vals, type);
 773         default:
 774                 return -EINVAL;
 775         }
 776 }
 777
 778 /**
 779  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
 780  * @str: The string to parse
 781  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 782  * @integer: The integer part of the number
 783  * @fract: The fractional part of the number
 784  * @scale_db: True if this should parse as dB
 785  *
 786  * Returns 0 on success, or a negative error code if the string could not be
 787  * parsed.
 788  */
 789 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
 790                                  int *integer, int *fract, bool scale_db)
 791 {
 792         int i = 0, f = 0;
 793         bool integer_part = true, negative = false;
 794
 795         if (fract_mult == 0) {
 796                 *fract = 0;
 797
 798                 return kstrtoint(str, 0, integer);
 799         }
 800
 801         if (str[0] == '-') {
 802                 negative = true;
 803                 str++;
 804         } else if (str[0] == '+') {
 805                 str++;
 806         }
 807
 808         while (*str) {
 809                 if ('0' <= *str && *str <= '9') {
 810                         if (integer_part) {
 811                                 i = i * 10 + *str - '0';
 812                         } else {
 813                                 f += fract_mult * (*str - '0');
 814                                 fract_mult /= 10;
 815                         }
 816                 } else if (*str == '\n') {
 817                         if (*(str + 1) == '\0')
 818                                 break;
 819                         else
 820                                 return -EINVAL;
 821                 } else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
 822                         /* Ignore the dB suffix */
 823                         str += sizeof(" dB") - 1;
 824                         continue;
 825                 } else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
 826                         /* Ignore the dB suffix */
 827                         str += sizeof("dB") - 1;
 828                         continue;
 829                 } else if (*str == '.' && integer_part) {
 830                         integer_part = false;
 831                 } else {
 832                         return -EINVAL;
 833                 }
 834                 str++;
 835         }
 836
 837         if (negative) {
 838                 if (i)
 839                         i = -i;
 840                 else
 841                         f = -f;
 842         }
 843
 844         *integer = i;
 845         *fract = f;
 846
 847         return 0;
 848 }
 849
 850 /**
 851  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 852  * @str: The string to parse
 853  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 854  * @integer: The integer part of the number
 855  * @fract: The fractional part of the number
 856  *
 857  * Returns 0 on success, or a negative error code if the string could not be
 858  * parsed.
 859  */
 860 int iio_str_to_fixpoint(const char *str, int fract_mult,
 861                         int *integer, int *fract)
 862 {
 863         return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
 864 }
 865 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 866
 867 static ssize_t iio_write_channel_info(struct device *dev,
 868                                       struct device_attribute *attr,
 869                                       const char *buf,
 870                                       size_t len)
 871 {
 872         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 873         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 874         int ret, fract_mult = 100000;
 875         int integer, fract = 0;
 876         bool is_char = false;
 877         bool scale_db = false;
 878
 879         /* Assumes decimal - precision based on number of digits */
 880         if (!indio_dev->info->write_raw)
 881                 return -EINVAL;
 882
 883         if (indio_dev->info->write_raw_get_fmt)
 884                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 885                         this_attr->c, this_attr->address)) {
 886                 case IIO_VAL_INT:
 887                         fract_mult = 0;
 888                         break;
 889                 case IIO_VAL_INT_PLUS_MICRO_DB:
 890                         scale_db = true;
 891                         /* fall through */
 892                 case IIO_VAL_INT_PLUS_MICRO:
 893                         fract_mult = 100000;
 894                         break;
 895                 case IIO_VAL_INT_PLUS_NANO:
 896                         fract_mult = 100000000;
 897                         break;
 898                 case IIO_VAL_CHAR:
 899                         is_char = true;
 900                         break;
 901                 default:
 902                         return -EINVAL;
 903                 }
 904
 905         if (is_char) {
 906                 char ch;
 907
 908                 if (sscanf(buf, "%c", &ch) != 1)
 909                         return -EINVAL;
 910                 integer = ch;
 911         } else {
 912                 ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 913                 if (ret)
 914                         return ret;
 915         }
 916         ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
 917                                     scale_db);
 918         if (ret)
 919                 return ret;
 920
 921         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 922                                          integer, fract, this_attr->address);
 923         if (ret)
 924                 return ret;
 925
 926         return len;
 927 }
 928
 929 static
 930 int __iio_device_attr_init(struct device_attribute *dev_attr,
 931                            const char *postfix,
 932                            struct iio_chan_spec const *chan,
 933                            ssize_t (*readfunc)(struct device *dev,
 934                                                struct device_attribute *attr,
 935                                                char *buf),
 936                            ssize_t (*writefunc)(struct device *dev,
 937                                                 struct device_attribute *attr,
 938                                                 const char *buf,
 939                                                 size_t len),
 940                            enum iio_shared_by shared_by)
 941 {
 942         int ret = 0;
 943         char *name = NULL;
 944         char *full_postfix;
 945         sysfs_attr_init(&dev_attr->attr);
 946
 947         /* Build up postfix of <extend_name>_<modifier>_postfix */
 948         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 949                 if (chan->extend_name)
 950                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 951                                                  iio_modifier_names[chan
 952                                                                     ->channel2],
 953                                                  chan->extend_name,
 954                                                  postfix);
 955                 else
 956                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 957                                                  iio_modifier_names[chan
 958                                                                     ->channel2],
 959                                                  postfix);
 960         } else {
 961                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 962                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 963                 else
 964                         full_postfix = kasprintf(GFP_KERNEL,
 965                                                  "%s_%s",
 966                                                  chan->extend_name,
 967                                                  postfix);
 968         }
 969         if (full_postfix == NULL)
 970                 return -ENOMEM;
 971
 972         if (chan->differential) { /* Differential can not have modifier */
 973                 switch (shared_by) {
 974                 case IIO_SHARED_BY_ALL:
 975                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 976                         break;
 977                 case IIO_SHARED_BY_DIR:
 978                         name = kasprintf(GFP_KERNEL, "%s_%s",
 979                                                 iio_direction[chan->output],
 980                                                 full_postfix);
 981                         break;
 982                 case IIO_SHARED_BY_TYPE:
 983                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 984                                             iio_direction[chan->output],
 985                                             iio_chan_type_name_spec[chan->type],
 986                                             iio_chan_type_name_spec[chan->type],
 987                                             full_postfix);
 988                         break;
 989                 case IIO_SEPARATE:
 990                         if (!chan->indexed) {
 991                                 WARN(1, "Differential channels must be indexed\n");
 992                                 ret = -EINVAL;
 993                                 goto error_free_full_postfix;
 994                         }
 995                         name = kasprintf(GFP_KERNEL,
 996                                             "%s_%s%d-%s%d_%s",
 997                                             iio_direction[chan->output],
 998                                             iio_chan_type_name_spec[chan->type],
 999                                             chan->channel,
1000                                             iio_chan_type_name_spec[chan->type],
1001                                             chan->channel2,
1002                                             full_postfix);
1003                         break;
1004                 }
1005         } else { /* Single ended */
1006                 switch (shared_by) {
1007                 case IIO_SHARED_BY_ALL:
1008                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1009                         break;
1010                 case IIO_SHARED_BY_DIR:
1011                         name = kasprintf(GFP_KERNEL, "%s_%s",
1012                                                 iio_direction[chan->output],
1013                                                 full_postfix);
1014                         break;
1015                 case IIO_SHARED_BY_TYPE:
1016                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1017                                             iio_direction[chan->output],
1018                                             iio_chan_type_name_spec[chan->type],
1019                                             full_postfix);
1020                         break;
1021
1022                 case IIO_SEPARATE:
1023                         if (chan->indexed)
1024                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1025                                                     iio_direction[chan->output],
1026                                                     iio_chan_type_name_spec[chan->type],
1027                                                     chan->channel,
1028                                                     full_postfix);
1029                         else
1030                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1031                                                     iio_direction[chan->output],
1032                                                     iio_chan_type_name_spec[chan->type],
1033                                                     full_postfix);
1034                         break;
1035                 }
1036         }
1037         if (name == NULL) {
1038                 ret = -ENOMEM;
1039                 goto error_free_full_postfix;
1040         }
1041         dev_attr->attr.name = name;
1042
1043         if (readfunc) {
1044                 dev_attr->attr.mode |= S_IRUGO;
1045                 dev_attr->show = readfunc;
1046         }
1047
1048         if (writefunc) {
1049                 dev_attr->attr.mode |= S_IWUSR;
1050                 dev_attr->store = writefunc;
1051         }
1052
1053 error_free_full_postfix:
1054         kfree(full_postfix);
1055
1056         return ret;
1057 }
1058
1059 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1060 {
1061         kfree(dev_attr->attr.name);
1062 }
1063
1064 int __iio_add_chan_devattr(const char *postfix,
1065                            struct iio_chan_spec const *chan,
1066                            ssize_t (*readfunc)(struct device *dev,
1067                                                struct device_attribute *attr,
1068                                                char *buf),
1069                            ssize_t (*writefunc)(struct device *dev,
1070                                                 struct device_attribute *attr,
1071                                                 const char *buf,
1072                                                 size_t len),
1073                            u64 mask,
1074                            enum iio_shared_by shared_by,
1075                            struct device *dev,
1076                            struct list_head *attr_list)
1077 {
1078         int ret;
1079         struct iio_dev_attr *iio_attr, *t;
1080
1081         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1082         if (iio_attr == NULL)
1083                 return -ENOMEM;
1084         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1085                                      postfix, chan,
1086                                      readfunc, writefunc, shared_by);
1087         if (ret)
1088                 goto error_iio_dev_attr_free;
1089         iio_attr->c = chan;
1090         iio_attr->address = mask;
1091         list_for_each_entry(t, attr_list, l)
1092                 if (strcmp(t->dev_attr.attr.name,
1093                            iio_attr->dev_attr.attr.name) == 0) {
1094                         if (shared_by == IIO_SEPARATE)
1095                                 dev_err(dev, "tried to double register : %s\n",
1096                                         t->dev_attr.attr.name);
1097                         ret = -EBUSY;
1098                         goto error_device_attr_deinit;
1099                 }
1100         list_add(&iio_attr->l, attr_list);
1101
1102         return 0;
1103
1104 error_device_attr_deinit:
1105         __iio_device_attr_deinit(&iio_attr->dev_attr);
1106 error_iio_dev_attr_free:
1107         kfree(iio_attr);
1108         return ret;
1109 }
1110
1111 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1112                                          struct iio_chan_spec const *chan,
1113                                          enum iio_shared_by shared_by,
1114                                          const long *infomask)
1115 {
1116         int i, ret, attrcount = 0;
1117
1118         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1119                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1120                         return -EINVAL;
1121                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1122                                              chan,
1123                                              &iio_read_channel_info,
1124                                              &iio_write_channel_info,
1125                                              i,
1126                                              shared_by,
1127                                              &indio_dev->dev,
1128                                              &indio_dev->channel_attr_list);
1129                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1130                         continue;
1131                 else if (ret < 0)
1132                         return ret;
1133                 attrcount++;
1134         }
1135
1136         return attrcount;
1137 }
1138
1139 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1140                                                struct iio_chan_spec const *chan,
1141                                                enum iio_shared_by shared_by,
1142                                                const long *infomask)
1143 {
1144         int i, ret, attrcount = 0;
1145         char *avail_postfix;
1146
1147         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1148                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1149                         return -EINVAL;
1150                 avail_postfix = kasprintf(GFP_KERNEL,
1151                                           "%s_available",
1152                                           iio_chan_info_postfix[i]);
1153                 if (!avail_postfix)
1154                         return -ENOMEM;
1155
1156                 ret = __iio_add_chan_devattr(avail_postfix,
1157                                              chan,
1158                                              &iio_read_channel_info_avail,
1159                                              NULL,
1160                                              i,
1161                                              shared_by,
1162                                              &indio_dev->dev,
1163                                              &indio_dev->channel_attr_list);
1164                 kfree(avail_postfix);
1165                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1166                         continue;
1167                 else if (ret < 0)
1168                         return ret;
1169                 attrcount++;
1170         }
1171
1172         return attrcount;
1173 }
1174
1175 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1176                                         struct iio_chan_spec const *chan)
1177 {
1178         int ret, attrcount = 0;
1179         const struct iio_chan_spec_ext_info *ext_info;
1180
1181         if (chan->channel < 0)
1182                 return 0;
1183         ret = iio_device_add_info_mask_type(indio_dev, chan,
1184                                             IIO_SEPARATE,
1185                                             &chan->info_mask_separate);
1186         if (ret < 0)
1187                 return ret;
1188         attrcount += ret;
1189
1190         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1191                                                   IIO_SEPARATE,
1192                                                   &chan->
1193                                                   info_mask_separate_available);
1194         if (ret < 0)
1195                 return ret;
1196         attrcount += ret;
1197
1198         ret = iio_device_add_info_mask_type(indio_dev, chan,
1199                                             IIO_SHARED_BY_TYPE,
1200                                             &chan->info_mask_shared_by_type);
1201         if (ret < 0)
1202                 return ret;
1203         attrcount += ret;
1204
1205         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1206                                                   IIO_SHARED_BY_TYPE,
1207                                                   &chan->
1208                                                   info_mask_shared_by_type_available);
1209         if (ret < 0)
1210                 return ret;
1211         attrcount += ret;
1212
1213         ret = iio_device_add_info_mask_type(indio_dev, chan,
1214                                             IIO_SHARED_BY_DIR,
1215                                             &chan->info_mask_shared_by_dir);
1216         if (ret < 0)
1217                 return ret;
1218         attrcount += ret;
1219
1220         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1221                                                   IIO_SHARED_BY_DIR,
1222                                                   &chan->info_mask_shared_by_dir_available);
1223         if (ret < 0)
1224                 return ret;
1225         attrcount += ret;
1226
1227         ret = iio_device_add_info_mask_type(indio_dev, chan,
1228                                             IIO_SHARED_BY_ALL,
1229                                             &chan->info_mask_shared_by_all);
1230         if (ret < 0)
1231                 return ret;
1232         attrcount += ret;
1233
1234         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1235                                                   IIO_SHARED_BY_ALL,
1236                                                   &chan->info_mask_shared_by_all_available);
1237         if (ret < 0)
1238                 return ret;
1239         attrcount += ret;
1240
1241         if (chan->ext_info) {
1242                 unsigned int i = 0;
1243                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1244                         ret = __iio_add_chan_devattr(ext_info->name,
1245                                         chan,
1246                                         ext_info->read ?
1247                                             &iio_read_channel_ext_info : NULL,
1248                                         ext_info->write ?
1249                                             &iio_write_channel_ext_info : NULL,
1250                                         i,
1251                                         ext_info->shared,
1252                                         &indio_dev->dev,
1253                                         &indio_dev->channel_attr_list);
1254                         i++;
1255                         if (ret == -EBUSY && ext_info->shared)
1256                                 continue;
1257
1258                         if (ret)
1259                                 return ret;
1260
1261                         attrcount++;
1262                 }
1263         }
1264
1265         return attrcount;
1266 }
1267
1268 /**
1269  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1270  * @attr_list: List of IIO device attributes
1271  *
1272  * This function frees the memory allocated for each of the IIO device
1273  * attributes in the list.
1274  */
1275 void iio_free_chan_devattr_list(struct list_head *attr_list)
1276 {
1277         struct iio_dev_attr *p, *n;
1278
1279         list_for_each_entry_safe(p, n, attr_list, l) {
1280                 kfree(p->dev_attr.attr.name);
1281                 list_del(&p->l);
1282                 kfree(p);
1283         }
1284 }
1285
1286 static ssize_t iio_show_dev_name(struct device *dev,
1287                                  struct device_attribute *attr,
1288                                  char *buf)
1289 {
1290         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1291         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1292 }
1293
1294 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1295
1296 static ssize_t iio_show_dev_label(struct device *dev,
1297                                  struct device_attribute *attr,
1298                                  char *buf)
1299 {
1300         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1301         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
1302 }
1303
1304 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1305
1306 static ssize_t iio_show_timestamp_clock(struct device *dev,
1307                                         struct device_attribute *attr,
1308                                         char *buf)
1309 {
1310         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1311         const clockid_t clk = iio_device_get_clock(indio_dev);
1312         const char *name;
1313         ssize_t sz;
1314
1315         switch (clk) {
1316         case CLOCK_REALTIME:
1317                 name = "realtime\n";
1318                 sz = sizeof("realtime\n");
1319                 break;
1320         case CLOCK_MONOTONIC:
1321                 name = "monotonic\n";
1322                 sz = sizeof("monotonic\n");
1323                 break;
1324         case CLOCK_MONOTONIC_RAW:
1325                 name = "monotonic_raw\n";
1326                 sz = sizeof("monotonic_raw\n");
1327                 break;
1328         case CLOCK_REALTIME_COARSE:
1329                 name = "realtime_coarse\n";
1330                 sz = sizeof("realtime_coarse\n");
1331                 break;
1332         case CLOCK_MONOTONIC_COARSE:
1333                 name = "monotonic_coarse\n";
1334                 sz = sizeof("monotonic_coarse\n");
1335                 break;
1336         case CLOCK_BOOTTIME:
1337                 name = "boottime\n";
1338                 sz = sizeof("boottime\n");
1339                 break;
1340         case CLOCK_TAI:
1341                 name = "tai\n";
1342                 sz = sizeof("tai\n");
1343                 break;
1344         default:
1345                 BUG();
1346         }
1347
1348         memcpy(buf, name, sz);
1349         return sz;
1350 }
1351
1352 static ssize_t iio_store_timestamp_clock(struct device *dev,
1353                                          struct device_attribute *attr,
1354                                          const char *buf, size_t len)
1355 {
1356         clockid_t clk;
1357         int ret;
1358
1359         if (sysfs_streq(buf, "realtime"))
1360                 clk = CLOCK_REALTIME;
1361         else if (sysfs_streq(buf, "monotonic"))
1362                 clk = CLOCK_MONOTONIC;
1363         else if (sysfs_streq(buf, "monotonic_raw"))
1364                 clk = CLOCK_MONOTONIC_RAW;
1365         else if (sysfs_streq(buf, "realtime_coarse"))
1366                 clk = CLOCK_REALTIME_COARSE;
1367         else if (sysfs_streq(buf, "monotonic_coarse"))
1368                 clk = CLOCK_MONOTONIC_COARSE;
1369         else if (sysfs_streq(buf, "boottime"))
1370                 clk = CLOCK_BOOTTIME;
1371         else if (sysfs_streq(buf, "tai"))
1372                 clk = CLOCK_TAI;
1373         else
1374                 return -EINVAL;
1375
1376         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1377         if (ret)
1378                 return ret;
1379
1380         return len;
1381 }
1382
1383 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1384                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1385
1386 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1387 {
1388         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1389         struct iio_dev_attr *p;
1390         struct attribute **attr, *clk = NULL;
1391
1392         /* First count elements in any existing group */
1393         if (indio_dev->info->attrs) {
1394                 attr = indio_dev->info->attrs->attrs;
1395                 while (*attr++ != NULL)
1396                         attrcount_orig++;
1397         }
1398         attrcount = attrcount_orig;
1399         /*
1400          * New channel registration method - relies on the fact a group does
1401          * not need to be initialized if its name is NULL.
1402          */
1403         if (indio_dev->channels)
1404                 for (i = 0; i < indio_dev->num_channels; i++) {
1405                         const struct iio_chan_spec *chan =
1406                                 &indio_dev->channels[i];
1407
1408                         if (chan->type == IIO_TIMESTAMP)
1409                                 clk = &dev_attr_current_timestamp_clock.attr;
1410
1411                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1412                         if (ret < 0)
1413                                 goto error_clear_attrs;
1414                         attrcount += ret;
1415                 }
1416
1417         if (indio_dev->event_interface)
1418                 clk = &dev_attr_current_timestamp_clock.attr;
1419
1420         if (indio_dev->name)
1421                 attrcount++;
1422         if (indio_dev->label)
1423                 attrcount++;
1424         if (clk)
1425                 attrcount++;
1426
1427         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1428                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1429                                                    GFP_KERNEL);
1430         if (indio_dev->chan_attr_group.attrs == NULL) {
1431                 ret = -ENOMEM;
1432                 goto error_clear_attrs;
1433         }
1434         /* Copy across original attributes */
1435         if (indio_dev->info->attrs)
1436                 memcpy(indio_dev->chan_attr_group.attrs,
1437                        indio_dev->info->attrs->attrs,
1438                        sizeof(indio_dev->chan_attr_group.attrs[0])
1439                        *attrcount_orig);
1440         attrn = attrcount_orig;
1441         /* Add all elements from the list. */
1442         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1443                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1444         if (indio_dev->name)
1445                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1446         if (indio_dev->label)
1447                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1448         if (clk)
1449                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1450
1451         indio_dev->groups[indio_dev->groupcounter++] =
1452                 &indio_dev->chan_attr_group;
1453
1454         return 0;
1455
1456 error_clear_attrs:
1457         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1458
1459         return ret;
1460 }
1461
1462 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1463 {
1464
1465         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1466         kfree(indio_dev->chan_attr_group.attrs);
1467         indio_dev->chan_attr_group.attrs = NULL;
1468 }
1469
1470 static void iio_dev_release(struct device *device)
1471 {
1472         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1473         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1474                 iio_device_unregister_trigger_consumer(indio_dev);
1475         iio_device_unregister_eventset(indio_dev);
1476         iio_device_unregister_sysfs(indio_dev);
1477
1478         iio_buffer_put(indio_dev->buffer);
1479
1480         ida_simple_remove(&iio_ida, indio_dev->id);
1481         kfree(indio_dev);
1482 }
1483
1484 struct device_type iio_device_type = {
1485         .name = "iio_device",
1486         .release = iio_dev_release,
1487 };
1488
1489 /**
1490  * iio_device_alloc() - allocate an iio_dev from a driver
1491  * @sizeof_priv:        Space to allocate for private structure.
1492  **/
1493 struct iio_dev *iio_device_alloc(int sizeof_priv)
1494 {
1495         struct iio_dev *dev;
1496         size_t alloc_size;
1497
1498         alloc_size = sizeof(struct iio_dev);
1499         if (sizeof_priv) {
1500                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1501                 alloc_size += sizeof_priv;
1502         }
1503         /* ensure 32-byte alignment of whole construct ? */
1504         alloc_size += IIO_ALIGN - 1;
1505
1506         dev = kzalloc(alloc_size, GFP_KERNEL);
1507
1508         if (dev) {
1509                 dev->dev.groups = dev->groups;
1510                 dev->dev.type = &iio_device_type;
1511                 dev->dev.bus = &iio_bus_type;
1512                 device_initialize(&dev->dev);
1513                 dev_set_drvdata(&dev->dev, (void *)dev);
1514                 mutex_init(&dev->mlock);
1515                 mutex_init(&dev->info_exist_lock);
1516                 INIT_LIST_HEAD(&dev->channel_attr_list);
1517
1518                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1519                 if (dev->id < 0) {
1520                         /* cannot use a dev_err as the name isn't available */
1521                         pr_err("failed to get device id\n");
1522                         kfree(dev);
1523                         return NULL;
1524                 }
1525                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
1526                 INIT_LIST_HEAD(&dev->buffer_list);
1527         }
1528
1529         return dev;
1530 }
1531 EXPORT_SYMBOL(iio_device_alloc);
1532
1533 /**
1534  * iio_device_free() - free an iio_dev from a driver
1535  * @dev:                the iio_dev associated with the device
1536  **/
1537 void iio_device_free(struct iio_dev *dev)
1538 {
1539         if (dev)
1540                 put_device(&dev->dev);
1541 }
1542 EXPORT_SYMBOL(iio_device_free);
1543
1544 static void devm_iio_device_release(struct device *dev, void *res)
1545 {
1546         iio_device_free(*(struct iio_dev **)res);
1547 }
1548
1549 int devm_iio_device_match(struct device *dev, void *res, void *data)
1550 {
1551         struct iio_dev **r = res;
1552         if (!r || !*r) {
1553                 WARN_ON(!r || !*r);
1554                 return 0;
1555         }
1556         return *r == data;
1557 }
1558 EXPORT_SYMBOL_GPL(devm_iio_device_match);
1559
1560 /**
1561  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1562  * @dev:                Device to allocate iio_dev for
1563  * @sizeof_priv:        Space to allocate for private structure.
1564  *
1565  * Managed iio_device_alloc. iio_dev allocated with this function is
1566  * automatically freed on driver detach.
1567  *
1568  * If an iio_dev allocated with this function needs to be freed separately,
1569  * devm_iio_device_free() must be used.
1570  *
1571  * RETURNS:
1572  * Pointer to allocated iio_dev on success, NULL on failure.
1573  */
1574 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1575 {
1576         struct iio_dev **ptr, *iio_dev;
1577
1578         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1579                            GFP_KERNEL);
1580         if (!ptr)
1581                 return NULL;
1582
1583         iio_dev = iio_device_alloc(sizeof_priv);
1584         if (iio_dev) {
1585                 *ptr = iio_dev;
1586                 devres_add(dev, ptr);
1587         } else {
1588                 devres_free(ptr);
1589         }
1590
1591         return iio_dev;
1592 }
1593 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1594
1595 /**
1596  * devm_iio_device_free - Resource-managed iio_device_free()
1597  * @dev:                Device this iio_dev belongs to
1598  * @iio_dev:            the iio_dev associated with the device
1599  *
1600  * Free iio_dev allocated with devm_iio_device_alloc().
1601  */
1602 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1603 {
1604         int rc;
1605
1606         rc = devres_release(dev, devm_iio_device_release,
1607                             devm_iio_device_match, iio_dev);
1608         WARN_ON(rc);
1609 }
1610 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1611
1612 /**
1613  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1614  * @inode:      Inode structure for identifying the device in the file system
1615  * @filp:       File structure for iio device used to keep and later access
1616  *              private data
1617  *
1618  * Return: 0 on success or -EBUSY if the device is already opened
1619  **/
1620 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1621 {
1622         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1623                                                 struct iio_dev, chrdev);
1624
1625         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1626                 return -EBUSY;
1627
1628         iio_device_get(indio_dev);
1629
1630         filp->private_data = indio_dev;
1631
1632         return 0;
1633 }
1634
1635 /**
1636  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1637  * @inode:      Inode structure pointer for the char device
1638  * @filp:       File structure pointer for the char device
1639  *
1640  * Return: 0 for successful release
1641  */
1642 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1643 {
1644         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1645                                                 struct iio_dev, chrdev);
1646         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1647         iio_device_put(indio_dev);
1648
1649         return 0;
1650 }
1651
1652 /* Somewhat of a cross file organization violation - ioctls here are actually
1653  * event related */
1654 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1655 {
1656         struct iio_dev *indio_dev = filp->private_data;
1657         int __user *ip = (int __user *)arg;
1658         int fd;
1659
1660         if (!indio_dev->info)
1661                 return -ENODEV;
1662
1663         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1664                 fd = iio_event_getfd(indio_dev);
1665                 if (fd < 0)
1666                         return fd;
1667                 if (copy_to_user(ip, &fd, sizeof(fd)))
1668                         return -EFAULT;
1669                 return 0;
1670         }
1671         return -EINVAL;
1672 }
1673
1674 static const struct file_operations iio_buffer_fileops = {
1675         .read = iio_buffer_read_outer_addr,
1676         .release = iio_chrdev_release,
1677         .open = iio_chrdev_open,
1678         .poll = iio_buffer_poll_addr,
1679         .owner = THIS_MODULE,
1680         .llseek = noop_llseek,
1681         .unlocked_ioctl = iio_ioctl,
1682         .compat_ioctl = compat_ptr_ioctl,
1683 };
1684
1685 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1686 {
1687         int i, j;
1688         const struct iio_chan_spec *channels = indio_dev->channels;
1689
1690         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1691                 return 0;
1692
1693         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1694                 if (channels[i].scan_index < 0)
1695                         continue;
1696                 for (j = i + 1; j < indio_dev->num_channels; j++)
1697                         if (channels[i].scan_index == channels[j].scan_index) {
1698                                 dev_err(&indio_dev->dev,
1699                                         "Duplicate scan index %d\n",
1700                                         channels[i].scan_index);
1701                                 return -EINVAL;
1702                         }
1703         }
1704
1705         return 0;
1706 }
1707
1708 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1709
1710 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1711 {
1712         int ret;
1713
1714         indio_dev->driver_module = this_mod;
1715         /* If the calling driver did not initialize of_node, do it here */
1716         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1717                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1718
1719         indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
1720                                            NULL);
1721
1722         ret = iio_check_unique_scan_index(indio_dev);
1723         if (ret < 0)
1724                 return ret;
1725
1726         if (!indio_dev->info)
1727                 return -EINVAL;
1728
1729         /* configure elements for the chrdev */
1730         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1731
1732         iio_device_register_debugfs(indio_dev);
1733
1734         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1735         if (ret) {
1736                 dev_err(indio_dev->dev.parent,
1737                         "Failed to create buffer sysfs interfaces\n");
1738                 goto error_unreg_debugfs;
1739         }
1740
1741         ret = iio_device_register_sysfs(indio_dev);
1742         if (ret) {
1743                 dev_err(indio_dev->dev.parent,
1744                         "Failed to register sysfs interfaces\n");
1745                 goto error_buffer_free_sysfs;
1746         }
1747         ret = iio_device_register_eventset(indio_dev);
1748         if (ret) {
1749                 dev_err(indio_dev->dev.parent,
1750                         "Failed to register event set\n");
1751                 goto error_free_sysfs;
1752         }
1753         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1754                 iio_device_register_trigger_consumer(indio_dev);
1755
1756         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1757                 indio_dev->setup_ops == NULL)
1758                 indio_dev->setup_ops = &noop_ring_setup_ops;
1759
1760         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1761
1762         indio_dev->chrdev.owner = this_mod;
1763
1764         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1765         if (ret < 0)
1766                 goto error_unreg_eventset;
1767
1768         return 0;
1769
1770 error_unreg_eventset:
1771         iio_device_unregister_eventset(indio_dev);
1772 error_free_sysfs:
1773         iio_device_unregister_sysfs(indio_dev);
1774 error_buffer_free_sysfs:
1775         iio_buffer_free_sysfs_and_mask(indio_dev);
1776 error_unreg_debugfs:
1777         iio_device_unregister_debugfs(indio_dev);
1778         return ret;
1779 }
1780 EXPORT_SYMBOL(__iio_device_register);
1781
1782 /**
1783  * iio_device_unregister() - unregister a device from the IIO subsystem
1784  * @indio_dev:          Device structure representing the device.
1785  **/
1786 void iio_device_unregister(struct iio_dev *indio_dev)
1787 {
1788         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1789
1790         mutex_lock(&indio_dev->info_exist_lock);
1791
1792         iio_device_unregister_debugfs(indio_dev);
1793
1794         iio_disable_all_buffers(indio_dev);
1795
1796         indio_dev->info = NULL;
1797
1798         iio_device_wakeup_eventset(indio_dev);
1799         iio_buffer_wakeup_poll(indio_dev);
1800
1801         mutex_unlock(&indio_dev->info_exist_lock);
1802
1803         iio_buffer_free_sysfs_and_mask(indio_dev);
1804 }
1805 EXPORT_SYMBOL(iio_device_unregister);
1806
1807 static void devm_iio_device_unreg(struct device *dev, void *res)
1808 {
1809         iio_device_unregister(*(struct iio_dev **)res);
1810 }
1811
1812 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1813                                struct module *this_mod)
1814 {
1815         struct iio_dev **ptr;
1816         int ret;
1817
1818         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1819         if (!ptr)
1820                 return -ENOMEM;
1821
1822         *ptr = indio_dev;
1823         ret = __iio_device_register(indio_dev, this_mod);
1824         if (!ret)
1825                 devres_add(dev, ptr);
1826         else
1827                 devres_free(ptr);
1828
1829         return ret;
1830 }
1831 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1832
1833 /**
1834  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1835  * @dev:        Device this iio_dev belongs to
1836  * @indio_dev:  the iio_dev associated with the device
1837  *
1838  * Unregister iio_dev registered with devm_iio_device_register().
1839  */
1840 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1841 {
1842         int rc;
1843
1844         rc = devres_release(dev, devm_iio_device_unreg,
1845                             devm_iio_device_match, indio_dev);
1846         WARN_ON(rc);
1847 }
1848 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1849
1850 /**
1851  * iio_device_claim_direct_mode - Keep device in direct mode
1852  * @indio_dev:  the iio_dev associated with the device
1853  *
1854  * If the device is in direct mode it is guaranteed to stay
1855  * that way until iio_device_release_direct_mode() is called.
1856  *
1857  * Use with iio_device_release_direct_mode()
1858  *
1859  * Returns: 0 on success, -EBUSY on failure
1860  */
1861 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1862 {
1863         mutex_lock(&indio_dev->mlock);
1864
1865         if (iio_buffer_enabled(indio_dev)) {
1866                 mutex_unlock(&indio_dev->mlock);
1867                 return -EBUSY;
1868         }
1869         return 0;
1870 }
1871 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1872
1873 /**
1874  * iio_device_release_direct_mode - releases claim on direct mode
1875  * @indio_dev:  the iio_dev associated with the device
1876  *
1877  * Release the claim. Device is no longer guaranteed to stay
1878  * in direct mode.
1879  *
1880  * Use with iio_device_claim_direct_mode()
1881  */
1882 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1883 {
1884         mutex_unlock(&indio_dev->mlock);
1885 }
1886 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1887
1888 subsys_initcall(iio_init);
1889 module_exit(iio_exit);
1890
1891 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1892 MODULE_DESCRIPTION("Industrial I/O core");
1893 MODULE_LICENSE("GPL");