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