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         [IIO_MOD_ETHANOL] = "ethanol",
 134         [IIO_MOD_H2] = "h2",
 135 };
 136
 137 /* relies on pairs of these shared then separate */
 138 static const char * const iio_chan_info_postfix[] = {
 139         [IIO_CHAN_INFO_RAW] = "raw",
 140         [IIO_CHAN_INFO_PROCESSED] = "input",
 141         [IIO_CHAN_INFO_SCALE] = "scale",
 142         [IIO_CHAN_INFO_OFFSET] = "offset",
 143         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 144         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 145         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 146         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 147         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 148         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 149         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 150         = "filter_low_pass_3db_frequency",
 151         [IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY]
 152         = "filter_high_pass_3db_frequency",
 153         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 154         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 155         [IIO_CHAN_INFO_PHASE] = "phase",
 156         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 157         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 158         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 159         [IIO_CHAN_INFO_ENABLE] = "en",
 160         [IIO_CHAN_INFO_CALIBHEIGHT] = "calibheight",
 161         [IIO_CHAN_INFO_CALIBWEIGHT] = "calibweight",
 162         [IIO_CHAN_INFO_DEBOUNCE_COUNT] = "debounce_count",
 163         [IIO_CHAN_INFO_DEBOUNCE_TIME] = "debounce_time",
 164         [IIO_CHAN_INFO_CALIBEMISSIVITY] = "calibemissivity",
 165         [IIO_CHAN_INFO_OVERSAMPLING_RATIO] = "oversampling_ratio",
 166         [IIO_CHAN_INFO_THERMOCOUPLE_TYPE] = "thermocouple_type",
 167 };
 168
 169 /**
 170  * iio_find_channel_from_si() - get channel from its scan index
 171  * @indio_dev:          device
 172  * @si:                 scan index to match
 173  */
 174 const struct iio_chan_spec
 175 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 176 {
 177         int i;
 178
 179         for (i = 0; i < indio_dev->num_channels; i++)
 180                 if (indio_dev->channels[i].scan_index == si)
 181                         return &indio_dev->channels[i];
 182         return NULL;
 183 }
 184
 185 /* This turns up an awful lot */
 186 ssize_t iio_read_const_attr(struct device *dev,
 187                             struct device_attribute *attr,
 188                             char *buf)
 189 {
 190         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 191 }
 192 EXPORT_SYMBOL(iio_read_const_attr);
 193
 194 /**
 195  * iio_device_set_clock() - Set current timestamping clock for the device
 196  * @indio_dev: IIO device structure containing the device
 197  * @clock_id: timestamping clock posix identifier to set.
 198  */
 199 int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 200 {
 201         int ret;
 202         const struct iio_event_interface *ev_int = indio_dev->event_interface;
 203
 204         ret = mutex_lock_interruptible(&indio_dev->mlock);
 205         if (ret)
 206                 return ret;
 207         if ((ev_int && iio_event_enabled(ev_int)) ||
 208             iio_buffer_enabled(indio_dev)) {
 209                 mutex_unlock(&indio_dev->mlock);
 210                 return -EBUSY;
 211         }
 212         indio_dev->clock_id = clock_id;
 213         mutex_unlock(&indio_dev->mlock);
 214
 215         return 0;
 216 }
 217 EXPORT_SYMBOL(iio_device_set_clock);
 218
 219 /**
 220  * iio_get_time_ns() - utility function to get a time stamp for events etc
 221  * @indio_dev: device
 222  */
 223 s64 iio_get_time_ns(const struct iio_dev *indio_dev)
 224 {
 225         struct timespec64 tp;
 226
 227         switch (iio_device_get_clock(indio_dev)) {
 228         case CLOCK_REALTIME:
 229                 return ktime_get_real_ns();
 230         case CLOCK_MONOTONIC:
 231                 return ktime_get_ns();
 232         case CLOCK_MONOTONIC_RAW:
 233                 return ktime_get_raw_ns();
 234         case CLOCK_REALTIME_COARSE:
 235                 return ktime_to_ns(ktime_get_coarse_real());
 236         case CLOCK_MONOTONIC_COARSE:
 237                 ktime_get_coarse_ts64(&tp);
 238                 return timespec64_to_ns(&tp);
 239         case CLOCK_BOOTTIME:
 240                 return ktime_get_boottime_ns();
 241         case CLOCK_TAI:
 242                 return ktime_get_clocktai_ns();
 243         default:
 244                 BUG();
 245         }
 246 }
 247 EXPORT_SYMBOL(iio_get_time_ns);
 248
 249 /**
 250  * iio_get_time_res() - utility function to get time stamp clock resolution in
 251  *                      nano seconds.
 252  * @indio_dev: device
 253  */
 254 unsigned int iio_get_time_res(const struct iio_dev *indio_dev)
 255 {
 256         switch (iio_device_get_clock(indio_dev)) {
 257         case CLOCK_REALTIME:
 258         case CLOCK_MONOTONIC:
 259         case CLOCK_MONOTONIC_RAW:
 260         case CLOCK_BOOTTIME:
 261         case CLOCK_TAI:
 262                 return hrtimer_resolution;
 263         case CLOCK_REALTIME_COARSE:
 264         case CLOCK_MONOTONIC_COARSE:
 265                 return LOW_RES_NSEC;
 266         default:
 267                 BUG();
 268         }
 269 }
 270 EXPORT_SYMBOL(iio_get_time_res);
 271
 272 static int __init iio_init(void)
 273 {
 274         int ret;
 275
 276         /* Register sysfs bus */
 277         ret  = bus_register(&iio_bus_type);
 278         if (ret < 0) {
 279                 pr_err("could not register bus type\n");
 280                 goto error_nothing;
 281         }
 282
 283         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 284         if (ret < 0) {
 285                 pr_err("failed to allocate char dev region\n");
 286                 goto error_unregister_bus_type;
 287         }
 288
 289         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 290
 291         return 0;
 292
 293 error_unregister_bus_type:
 294         bus_unregister(&iio_bus_type);
 295 error_nothing:
 296         return ret;
 297 }
 298
 299 static void __exit iio_exit(void)
 300 {
 301         if (iio_devt)
 302                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 303         bus_unregister(&iio_bus_type);
 304         debugfs_remove(iio_debugfs_dentry);
 305 }
 306
 307 #if defined(CONFIG_DEBUG_FS)
 308 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 309                               size_t count, loff_t *ppos)
 310 {
 311         struct iio_dev *indio_dev = file->private_data;
 312         unsigned val = 0;
 313         int ret;
 314
 315         if (*ppos > 0)
 316                 return simple_read_from_buffer(userbuf, count, ppos,
 317                                                indio_dev->read_buf,
 318                                                indio_dev->read_buf_len);
 319
 320         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 321                                                   indio_dev->cached_reg_addr,
 322                                                   0, &val);
 323         if (ret) {
 324                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 325                 return ret;
 326         }
 327
 328         indio_dev->read_buf_len = snprintf(indio_dev->read_buf,
 329                                            sizeof(indio_dev->read_buf),
 330                                            "0x%X\n", val);
 331
 332         return simple_read_from_buffer(userbuf, count, ppos,
 333                                        indio_dev->read_buf,
 334                                        indio_dev->read_buf_len);
 335 }
 336
 337 static ssize_t iio_debugfs_write_reg(struct file *file,
 338                      const char __user *userbuf, size_t count, loff_t *ppos)
 339 {
 340         struct iio_dev *indio_dev = file->private_data;
 341         unsigned reg, val;
 342         char buf[80];
 343         int ret;
 344
 345         count = min_t(size_t, count, (sizeof(buf)-1));
 346         if (copy_from_user(buf, userbuf, count))
 347                 return -EFAULT;
 348
 349         buf[count] = 0;
 350
 351         ret = sscanf(buf, "%i %i", &reg, &val);
 352
 353         switch (ret) {
 354         case 1:
 355                 indio_dev->cached_reg_addr = reg;
 356                 break;
 357         case 2:
 358                 indio_dev->cached_reg_addr = reg;
 359                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 360                                                           val, NULL);
 361                 if (ret) {
 362                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 363                                 __func__);
 364                         return ret;
 365                 }
 366                 break;
 367         default:
 368                 return -EINVAL;
 369         }
 370
 371         return count;
 372 }
 373
 374 static const struct file_operations iio_debugfs_reg_fops = {
 375         .open = simple_open,
 376         .read = iio_debugfs_read_reg,
 377         .write = iio_debugfs_write_reg,
 378 };
 379
 380 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 381 {
 382         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 383 }
 384
 385 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 386 {
 387         if (indio_dev->info->debugfs_reg_access == NULL)
 388                 return;
 389
 390         if (!iio_debugfs_dentry)
 391                 return;
 392
 393         indio_dev->debugfs_dentry =
 394                 debugfs_create_dir(dev_name(&indio_dev->dev),
 395                                    iio_debugfs_dentry);
 396
 397         debugfs_create_file("direct_reg_access", 0644,
 398                             indio_dev->debugfs_dentry, indio_dev,
 399                             &iio_debugfs_reg_fops);
 400 }
 401 #else
 402 static void iio_device_register_debugfs(struct iio_dev *indio_dev)
 403 {
 404 }
 405
 406 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 407 {
 408 }
 409 #endif /* CONFIG_DEBUG_FS */
 410
 411 static ssize_t iio_read_channel_ext_info(struct device *dev,
 412                                      struct device_attribute *attr,
 413                                      char *buf)
 414 {
 415         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 416         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 417         const struct iio_chan_spec_ext_info *ext_info;
 418
 419         ext_info = &this_attr->c->ext_info[this_attr->address];
 420
 421         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 422 }
 423
 424 static ssize_t iio_write_channel_ext_info(struct device *dev,
 425                                      struct device_attribute *attr,
 426                                      const char *buf,
 427                                          size_t len)
 428 {
 429         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 430         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 431         const struct iio_chan_spec_ext_info *ext_info;
 432
 433         ext_info = &this_attr->c->ext_info[this_attr->address];
 434
 435         return ext_info->write(indio_dev, ext_info->private,
 436                                this_attr->c, buf, len);
 437 }
 438
 439 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 440         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 441 {
 442         const struct iio_enum *e = (const struct iio_enum *)priv;
 443         unsigned int i;
 444         size_t len = 0;
 445
 446         if (!e->num_items)
 447                 return 0;
 448
 449         for (i = 0; i < e->num_items; ++i)
 450                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 451
 452         /* replace last space with a newline */
 453         buf[len - 1] = '\n';
 454
 455         return len;
 456 }
 457 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 458
 459 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 460         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 461 {
 462         const struct iio_enum *e = (const struct iio_enum *)priv;
 463         int i;
 464
 465         if (!e->get)
 466                 return -EINVAL;
 467
 468         i = e->get(indio_dev, chan);
 469         if (i < 0)
 470                 return i;
 471         else if (i >= e->num_items)
 472                 return -EINVAL;
 473
 474         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 475 }
 476 EXPORT_SYMBOL_GPL(iio_enum_read);
 477
 478 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 479         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 480         size_t len)
 481 {
 482         const struct iio_enum *e = (const struct iio_enum *)priv;
 483         int ret;
 484
 485         if (!e->set)
 486                 return -EINVAL;
 487
 488         ret = __sysfs_match_string(e->items, e->num_items, buf);
 489         if (ret < 0)
 490                 return ret;
 491
 492         ret = e->set(indio_dev, chan, ret);
 493         return ret ? ret : len;
 494 }
 495 EXPORT_SYMBOL_GPL(iio_enum_write);
 496
 497 static const struct iio_mount_matrix iio_mount_idmatrix = {
 498         .rotation = {
 499                 "1", "0", "0",
 500                 "0", "1", "0",
 501                 "0", "0", "1"
 502         }
 503 };
 504
 505 static int iio_setup_mount_idmatrix(const struct device *dev,
 506                                     struct iio_mount_matrix *matrix)
 507 {
 508         *matrix = iio_mount_idmatrix;
 509         dev_info(dev, "mounting matrix not found: using identity...\n");
 510         return 0;
 511 }
 512
 513 ssize_t iio_show_mount_matrix(struct iio_dev *indio_dev, uintptr_t priv,
 514                               const struct iio_chan_spec *chan, char *buf)
 515 {
 516         const struct iio_mount_matrix *mtx = ((iio_get_mount_matrix_t *)
 517                                               priv)(indio_dev, chan);
 518
 519         if (IS_ERR(mtx))
 520                 return PTR_ERR(mtx);
 521
 522         if (!mtx)
 523                 mtx = &iio_mount_idmatrix;
 524
 525         return snprintf(buf, PAGE_SIZE, "%s, %s, %s; %s, %s, %s; %s, %s, %s\n",
 526                         mtx->rotation[0], mtx->rotation[1], mtx->rotation[2],
 527                         mtx->rotation[3], mtx->rotation[4], mtx->rotation[5],
 528                         mtx->rotation[6], mtx->rotation[7], mtx->rotation[8]);
 529 }
 530 EXPORT_SYMBOL_GPL(iio_show_mount_matrix);
 531
 532 /**
 533  * iio_read_mount_matrix() - retrieve iio device mounting matrix from
 534  *                           device "mount-matrix" property
 535  * @dev:        device the mounting matrix property is assigned to
 536  * @propname:   device specific mounting matrix property name
 537  * @matrix:     where to store retrieved matrix
 538  *
 539  * If device is assigned no mounting matrix property, a default 3x3 identity
 540  * matrix will be filled in.
 541  *
 542  * Return: 0 if success, or a negative error code on failure.
 543  */
 544 int iio_read_mount_matrix(struct device *dev, const char *propname,
 545                           struct iio_mount_matrix *matrix)
 546 {
 547         size_t len = ARRAY_SIZE(iio_mount_idmatrix.rotation);
 548         int err;
 549
 550         err = device_property_read_string_array(dev, propname,
 551                                                 matrix->rotation, len);
 552         if (err == len)
 553                 return 0;
 554
 555         if (err >= 0)
 556                 /* Invalid number of matrix entries. */
 557                 return -EINVAL;
 558
 559         if (err != -EINVAL)
 560                 /* Invalid matrix declaration format. */
 561                 return err;
 562
 563         /* Matrix was not declared at all: fallback to identity. */
 564         return iio_setup_mount_idmatrix(dev, matrix);
 565 }
 566 EXPORT_SYMBOL(iio_read_mount_matrix);
 567
 568 static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 569                                   int size, const int *vals)
 570 {
 571         unsigned long long tmp;
 572         int tmp0, tmp1;
 573         bool scale_db = false;
 574
 575         switch (type) {
 576         case IIO_VAL_INT:
 577                 return scnprintf(buf, len, "%d", vals[0]);
 578         case IIO_VAL_INT_PLUS_MICRO_DB:
 579                 scale_db = true;
 580                 /* fall through */
 581         case IIO_VAL_INT_PLUS_MICRO:
 582                 if (vals[1] < 0)
 583                         return scnprintf(buf, len, "-%d.%06u%s", abs(vals[0]),
 584                                         -vals[1], scale_db ? " dB" : "");
 585                 else
 586                         return scnprintf(buf, len, "%d.%06u%s", vals[0], vals[1],
 587                                         scale_db ? " dB" : "");
 588         case IIO_VAL_INT_PLUS_NANO:
 589                 if (vals[1] < 0)
 590                         return scnprintf(buf, len, "-%d.%09u", abs(vals[0]),
 591                                         -vals[1]);
 592                 else
 593                         return scnprintf(buf, len, "%d.%09u", vals[0], vals[1]);
 594         case IIO_VAL_FRACTIONAL:
 595                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 596                 tmp1 = vals[1];
 597                 tmp0 = (int)div_s64_rem(tmp, 1000000000, &tmp1);
 598                 return scnprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 599         case IIO_VAL_FRACTIONAL_LOG2:
 600                 tmp = shift_right((s64)vals[0] * 1000000000LL, vals[1]);
 601                 tmp0 = (int)div_s64_rem(tmp, 1000000000LL, &tmp1);
 602                 return scnprintf(buf, len, "%d.%09u", tmp0, abs(tmp1));
 603         case IIO_VAL_INT_MULTIPLE:
 604         {
 605                 int i;
 606                 int l = 0;
 607
 608                 for (i = 0; i < size; ++i) {
 609                         l += scnprintf(&buf[l], len - l, "%d ", vals[i]);
 610                         if (l >= len)
 611                                 break;
 612                 }
 613                 return l;
 614         }
 615         case IIO_VAL_CHAR:
 616                 return scnprintf(buf, len, "%c", (char)vals[0]);
 617         default:
 618                 return 0;
 619         }
 620 }
 621
 622 /**
 623  * iio_format_value() - Formats a IIO value into its string representation
 624  * @buf:        The buffer to which the formatted value gets written
 625  *              which is assumed to be big enough (i.e. PAGE_SIZE).
 626  * @type:       One of the IIO_VAL_* constants. This decides how the val
 627  *              and val2 parameters are formatted.
 628  * @size:       Number of IIO value entries contained in vals
 629  * @vals:       Pointer to the values, exact meaning depends on the
 630  *              type parameter.
 631  *
 632  * Return: 0 by default, a negative number on failure or the
 633  *         total number of characters written for a type that belongs
 634  *         to the IIO_VAL_* constant.
 635  */
 636 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 637 {
 638         ssize_t len;
 639
 640         len = __iio_format_value(buf, PAGE_SIZE, type, size, vals);
 641         if (len >= PAGE_SIZE - 1)
 642                 return -EFBIG;
 643
 644         return len + sprintf(buf + len, "\n");
 645 }
 646 EXPORT_SYMBOL_GPL(iio_format_value);
 647
 648 static ssize_t iio_read_channel_info(struct device *dev,
 649                                      struct device_attribute *attr,
 650                                      char *buf)
 651 {
 652         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 653         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 654         int vals[INDIO_MAX_RAW_ELEMENTS];
 655         int ret;
 656         int val_len = 2;
 657
 658         if (indio_dev->info->read_raw_multi)
 659                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 660                                                         INDIO_MAX_RAW_ELEMENTS,
 661                                                         vals, &val_len,
 662                                                         this_attr->address);
 663         else
 664                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 665                                     &vals[0], &vals[1], this_attr->address);
 666
 667         if (ret < 0)
 668                 return ret;
 669
 670         return iio_format_value(buf, ret, val_len, vals);
 671 }
 672
 673 static ssize_t iio_format_avail_list(char *buf, const int *vals,
 674                                      int type, int length)
 675 {
 676         int i;
 677         ssize_t len = 0;
 678
 679         switch (type) {
 680         case IIO_VAL_INT:
 681                 for (i = 0; i < length; i++) {
 682                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 683                                                   type, 1, &vals[i]);
 684                         if (len >= PAGE_SIZE)
 685                                 return -EFBIG;
 686                         if (i < length - 1)
 687                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 688                                                 " ");
 689                         else
 690                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 691                                                 "\n");
 692                         if (len >= PAGE_SIZE)
 693                                 return -EFBIG;
 694                 }
 695                 break;
 696         default:
 697                 for (i = 0; i < length / 2; i++) {
 698                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 699                                                   type, 2, &vals[i * 2]);
 700                         if (len >= PAGE_SIZE)
 701                                 return -EFBIG;
 702                         if (i < length / 2 - 1)
 703                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 704                                                 " ");
 705                         else
 706                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 707                                                 "\n");
 708                         if (len >= PAGE_SIZE)
 709                                 return -EFBIG;
 710                 }
 711         }
 712
 713         return len;
 714 }
 715
 716 static ssize_t iio_format_avail_range(char *buf, const int *vals, int type)
 717 {
 718         int i;
 719         ssize_t len;
 720
 721         len = snprintf(buf, PAGE_SIZE, "[");
 722         switch (type) {
 723         case IIO_VAL_INT:
 724                 for (i = 0; i < 3; i++) {
 725                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 726                                                   type, 1, &vals[i]);
 727                         if (len >= PAGE_SIZE)
 728                                 return -EFBIG;
 729                         if (i < 2)
 730                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 731                                                 " ");
 732                         else
 733                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 734                                                 "]\n");
 735                         if (len >= PAGE_SIZE)
 736                                 return -EFBIG;
 737                 }
 738                 break;
 739         default:
 740                 for (i = 0; i < 3; i++) {
 741                         len += __iio_format_value(buf + len, PAGE_SIZE - len,
 742                                                   type, 2, &vals[i * 2]);
 743                         if (len >= PAGE_SIZE)
 744                                 return -EFBIG;
 745                         if (i < 2)
 746                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 747                                                 " ");
 748                         else
 749                                 len += scnprintf(buf + len, PAGE_SIZE - len,
 750                                                 "]\n");
 751                         if (len >= PAGE_SIZE)
 752                                 return -EFBIG;
 753                 }
 754         }
 755
 756         return len;
 757 }
 758
 759 static ssize_t iio_read_channel_info_avail(struct device *dev,
 760                                            struct device_attribute *attr,
 761                                            char *buf)
 762 {
 763         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 764         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 765         const int *vals;
 766         int ret;
 767         int length;
 768         int type;
 769
 770         ret = indio_dev->info->read_avail(indio_dev, this_attr->c,
 771                                           &vals, &type, &length,
 772                                           this_attr->address);
 773
 774         if (ret < 0)
 775                 return ret;
 776         switch (ret) {
 777         case IIO_AVAIL_LIST:
 778                 return iio_format_avail_list(buf, vals, type, length);
 779         case IIO_AVAIL_RANGE:
 780                 return iio_format_avail_range(buf, vals, type);
 781         default:
 782                 return -EINVAL;
 783         }
 784 }
 785
 786 /**
 787  * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
 788  * @str: The string to parse
 789  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 790  * @integer: The integer part of the number
 791  * @fract: The fractional part of the number
 792  * @scale_db: True if this should parse as dB
 793  *
 794  * Returns 0 on success, or a negative error code if the string could not be
 795  * parsed.
 796  */
 797 static int __iio_str_to_fixpoint(const char *str, int fract_mult,
 798                                  int *integer, int *fract, bool scale_db)
 799 {
 800         int i = 0, f = 0;
 801         bool integer_part = true, negative = false;
 802
 803         if (fract_mult == 0) {
 804                 *fract = 0;
 805
 806                 return kstrtoint(str, 0, integer);
 807         }
 808
 809         if (str[0] == '-') {
 810                 negative = true;
 811                 str++;
 812         } else if (str[0] == '+') {
 813                 str++;
 814         }
 815
 816         while (*str) {
 817                 if ('0' <= *str && *str <= '9') {
 818                         if (integer_part) {
 819                                 i = i * 10 + *str - '0';
 820                         } else {
 821                                 f += fract_mult * (*str - '0');
 822                                 fract_mult /= 10;
 823                         }
 824                 } else if (*str == '\n') {
 825                         if (*(str + 1) == '\0')
 826                                 break;
 827                         else
 828                                 return -EINVAL;
 829                 } else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
 830                         /* Ignore the dB suffix */
 831                         str += sizeof(" dB") - 1;
 832                         continue;
 833                 } else if (!strncmp(str, "dB", sizeof("dB") - 1) && scale_db) {
 834                         /* Ignore the dB suffix */
 835                         str += sizeof("dB") - 1;
 836                         continue;
 837                 } else if (*str == '.' && integer_part) {
 838                         integer_part = false;
 839                 } else {
 840                         return -EINVAL;
 841                 }
 842                 str++;
 843         }
 844
 845         if (negative) {
 846                 if (i)
 847                         i = -i;
 848                 else
 849                         f = -f;
 850         }
 851
 852         *integer = i;
 853         *fract = f;
 854
 855         return 0;
 856 }
 857
 858 /**
 859  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 860  * @str: The string to parse
 861  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 862  * @integer: The integer part of the number
 863  * @fract: The fractional part of the number
 864  *
 865  * Returns 0 on success, or a negative error code if the string could not be
 866  * parsed.
 867  */
 868 int iio_str_to_fixpoint(const char *str, int fract_mult,
 869                         int *integer, int *fract)
 870 {
 871         return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
 872 }
 873 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 874
 875 static ssize_t iio_write_channel_info(struct device *dev,
 876                                       struct device_attribute *attr,
 877                                       const char *buf,
 878                                       size_t len)
 879 {
 880         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 881         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 882         int ret, fract_mult = 100000;
 883         int integer, fract = 0;
 884         bool is_char = false;
 885         bool scale_db = false;
 886
 887         /* Assumes decimal - precision based on number of digits */
 888         if (!indio_dev->info->write_raw)
 889                 return -EINVAL;
 890
 891         if (indio_dev->info->write_raw_get_fmt)
 892                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 893                         this_attr->c, this_attr->address)) {
 894                 case IIO_VAL_INT:
 895                         fract_mult = 0;
 896                         break;
 897                 case IIO_VAL_INT_PLUS_MICRO_DB:
 898                         scale_db = true;
 899                         /* fall through */
 900                 case IIO_VAL_INT_PLUS_MICRO:
 901                         fract_mult = 100000;
 902                         break;
 903                 case IIO_VAL_INT_PLUS_NANO:
 904                         fract_mult = 100000000;
 905                         break;
 906                 case IIO_VAL_CHAR:
 907                         is_char = true;
 908                         break;
 909                 default:
 910                         return -EINVAL;
 911                 }
 912
 913         if (is_char) {
 914                 char ch;
 915
 916                 if (sscanf(buf, "%c", &ch) != 1)
 917                         return -EINVAL;
 918                 integer = ch;
 919         } else {
 920                 ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
 921                                             scale_db);
 922                 if (ret)
 923                         return ret;
 924         }
 925
 926         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 927                                          integer, fract, this_attr->address);
 928         if (ret)
 929                 return ret;
 930
 931         return len;
 932 }
 933
 934 static
 935 int __iio_device_attr_init(struct device_attribute *dev_attr,
 936                            const char *postfix,
 937                            struct iio_chan_spec const *chan,
 938                            ssize_t (*readfunc)(struct device *dev,
 939                                                struct device_attribute *attr,
 940                                                char *buf),
 941                            ssize_t (*writefunc)(struct device *dev,
 942                                                 struct device_attribute *attr,
 943                                                 const char *buf,
 944                                                 size_t len),
 945                            enum iio_shared_by shared_by)
 946 {
 947         int ret = 0;
 948         char *name = NULL;
 949         char *full_postfix;
 950         sysfs_attr_init(&dev_attr->attr);
 951
 952         /* Build up postfix of <extend_name>_<modifier>_postfix */
 953         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 954                 if (chan->extend_name)
 955                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 956                                                  iio_modifier_names[chan
 957                                                                     ->channel2],
 958                                                  chan->extend_name,
 959                                                  postfix);
 960                 else
 961                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 962                                                  iio_modifier_names[chan
 963                                                                     ->channel2],
 964                                                  postfix);
 965         } else {
 966                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 967                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 968                 else
 969                         full_postfix = kasprintf(GFP_KERNEL,
 970                                                  "%s_%s",
 971                                                  chan->extend_name,
 972                                                  postfix);
 973         }
 974         if (full_postfix == NULL)
 975                 return -ENOMEM;
 976
 977         if (chan->differential) { /* Differential can not have modifier */
 978                 switch (shared_by) {
 979                 case IIO_SHARED_BY_ALL:
 980                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 981                         break;
 982                 case IIO_SHARED_BY_DIR:
 983                         name = kasprintf(GFP_KERNEL, "%s_%s",
 984                                                 iio_direction[chan->output],
 985                                                 full_postfix);
 986                         break;
 987                 case IIO_SHARED_BY_TYPE:
 988                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 989                                             iio_direction[chan->output],
 990                                             iio_chan_type_name_spec[chan->type],
 991                                             iio_chan_type_name_spec[chan->type],
 992                                             full_postfix);
 993                         break;
 994                 case IIO_SEPARATE:
 995                         if (!chan->indexed) {
 996                                 WARN(1, "Differential channels must be indexed\n");
 997                                 ret = -EINVAL;
 998                                 goto error_free_full_postfix;
 999                         }
1000                         name = kasprintf(GFP_KERNEL,
1001                                             "%s_%s%d-%s%d_%s",
1002                                             iio_direction[chan->output],
1003                                             iio_chan_type_name_spec[chan->type],
1004                                             chan->channel,
1005                                             iio_chan_type_name_spec[chan->type],
1006                                             chan->channel2,
1007                                             full_postfix);
1008                         break;
1009                 }
1010         } else { /* Single ended */
1011                 switch (shared_by) {
1012                 case IIO_SHARED_BY_ALL:
1013                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
1014                         break;
1015                 case IIO_SHARED_BY_DIR:
1016                         name = kasprintf(GFP_KERNEL, "%s_%s",
1017                                                 iio_direction[chan->output],
1018                                                 full_postfix);
1019                         break;
1020                 case IIO_SHARED_BY_TYPE:
1021                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1022                                             iio_direction[chan->output],
1023                                             iio_chan_type_name_spec[chan->type],
1024                                             full_postfix);
1025                         break;
1026
1027                 case IIO_SEPARATE:
1028                         if (chan->indexed)
1029                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
1030                                                     iio_direction[chan->output],
1031                                                     iio_chan_type_name_spec[chan->type],
1032                                                     chan->channel,
1033                                                     full_postfix);
1034                         else
1035                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
1036                                                     iio_direction[chan->output],
1037                                                     iio_chan_type_name_spec[chan->type],
1038                                                     full_postfix);
1039                         break;
1040                 }
1041         }
1042         if (name == NULL) {
1043                 ret = -ENOMEM;
1044                 goto error_free_full_postfix;
1045         }
1046         dev_attr->attr.name = name;
1047
1048         if (readfunc) {
1049                 dev_attr->attr.mode |= S_IRUGO;
1050                 dev_attr->show = readfunc;
1051         }
1052
1053         if (writefunc) {
1054                 dev_attr->attr.mode |= S_IWUSR;
1055                 dev_attr->store = writefunc;
1056         }
1057
1058 error_free_full_postfix:
1059         kfree(full_postfix);
1060
1061         return ret;
1062 }
1063
1064 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
1065 {
1066         kfree(dev_attr->attr.name);
1067 }
1068
1069 int __iio_add_chan_devattr(const char *postfix,
1070                            struct iio_chan_spec const *chan,
1071                            ssize_t (*readfunc)(struct device *dev,
1072                                                struct device_attribute *attr,
1073                                                char *buf),
1074                            ssize_t (*writefunc)(struct device *dev,
1075                                                 struct device_attribute *attr,
1076                                                 const char *buf,
1077                                                 size_t len),
1078                            u64 mask,
1079                            enum iio_shared_by shared_by,
1080                            struct device *dev,
1081                            struct list_head *attr_list)
1082 {
1083         int ret;
1084         struct iio_dev_attr *iio_attr, *t;
1085
1086         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1087         if (iio_attr == NULL)
1088                 return -ENOMEM;
1089         ret = __iio_device_attr_init(&iio_attr->dev_attr,
1090                                      postfix, chan,
1091                                      readfunc, writefunc, shared_by);
1092         if (ret)
1093                 goto error_iio_dev_attr_free;
1094         iio_attr->c = chan;
1095         iio_attr->address = mask;
1096         list_for_each_entry(t, attr_list, l)
1097                 if (strcmp(t->dev_attr.attr.name,
1098                            iio_attr->dev_attr.attr.name) == 0) {
1099                         if (shared_by == IIO_SEPARATE)
1100                                 dev_err(dev, "tried to double register : %s\n",
1101                                         t->dev_attr.attr.name);
1102                         ret = -EBUSY;
1103                         goto error_device_attr_deinit;
1104                 }
1105         list_add(&iio_attr->l, attr_list);
1106
1107         return 0;
1108
1109 error_device_attr_deinit:
1110         __iio_device_attr_deinit(&iio_attr->dev_attr);
1111 error_iio_dev_attr_free:
1112         kfree(iio_attr);
1113         return ret;
1114 }
1115
1116 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
1117                                          struct iio_chan_spec const *chan,
1118                                          enum iio_shared_by shared_by,
1119                                          const long *infomask)
1120 {
1121         int i, ret, attrcount = 0;
1122
1123         for_each_set_bit(i, infomask, sizeof(*infomask)*8) {
1124                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1125                         return -EINVAL;
1126                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
1127                                              chan,
1128                                              &iio_read_channel_info,
1129                                              &iio_write_channel_info,
1130                                              i,
1131                                              shared_by,
1132                                              &indio_dev->dev,
1133                                              &indio_dev->channel_attr_list);
1134                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1135                         continue;
1136                 else if (ret < 0)
1137                         return ret;
1138                 attrcount++;
1139         }
1140
1141         return attrcount;
1142 }
1143
1144 static int iio_device_add_info_mask_type_avail(struct iio_dev *indio_dev,
1145                                                struct iio_chan_spec const *chan,
1146                                                enum iio_shared_by shared_by,
1147                                                const long *infomask)
1148 {
1149         int i, ret, attrcount = 0;
1150         char *avail_postfix;
1151
1152         for_each_set_bit(i, infomask, sizeof(*infomask) * 8) {
1153                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
1154                         return -EINVAL;
1155                 avail_postfix = kasprintf(GFP_KERNEL,
1156                                           "%s_available",
1157                                           iio_chan_info_postfix[i]);
1158                 if (!avail_postfix)
1159                         return -ENOMEM;
1160
1161                 ret = __iio_add_chan_devattr(avail_postfix,
1162                                              chan,
1163                                              &iio_read_channel_info_avail,
1164                                              NULL,
1165                                              i,
1166                                              shared_by,
1167                                              &indio_dev->dev,
1168                                              &indio_dev->channel_attr_list);
1169                 kfree(avail_postfix);
1170                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
1171                         continue;
1172                 else if (ret < 0)
1173                         return ret;
1174                 attrcount++;
1175         }
1176
1177         return attrcount;
1178 }
1179
1180 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
1181                                         struct iio_chan_spec const *chan)
1182 {
1183         int ret, attrcount = 0;
1184         const struct iio_chan_spec_ext_info *ext_info;
1185
1186         if (chan->channel < 0)
1187                 return 0;
1188         ret = iio_device_add_info_mask_type(indio_dev, chan,
1189                                             IIO_SEPARATE,
1190                                             &chan->info_mask_separate);
1191         if (ret < 0)
1192                 return ret;
1193         attrcount += ret;
1194
1195         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1196                                                   IIO_SEPARATE,
1197                                                   &chan->
1198                                                   info_mask_separate_available);
1199         if (ret < 0)
1200                 return ret;
1201         attrcount += ret;
1202
1203         ret = iio_device_add_info_mask_type(indio_dev, chan,
1204                                             IIO_SHARED_BY_TYPE,
1205                                             &chan->info_mask_shared_by_type);
1206         if (ret < 0)
1207                 return ret;
1208         attrcount += ret;
1209
1210         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1211                                                   IIO_SHARED_BY_TYPE,
1212                                                   &chan->
1213                                                   info_mask_shared_by_type_available);
1214         if (ret < 0)
1215                 return ret;
1216         attrcount += ret;
1217
1218         ret = iio_device_add_info_mask_type(indio_dev, chan,
1219                                             IIO_SHARED_BY_DIR,
1220                                             &chan->info_mask_shared_by_dir);
1221         if (ret < 0)
1222                 return ret;
1223         attrcount += ret;
1224
1225         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1226                                                   IIO_SHARED_BY_DIR,
1227                                                   &chan->info_mask_shared_by_dir_available);
1228         if (ret < 0)
1229                 return ret;
1230         attrcount += ret;
1231
1232         ret = iio_device_add_info_mask_type(indio_dev, chan,
1233                                             IIO_SHARED_BY_ALL,
1234                                             &chan->info_mask_shared_by_all);
1235         if (ret < 0)
1236                 return ret;
1237         attrcount += ret;
1238
1239         ret = iio_device_add_info_mask_type_avail(indio_dev, chan,
1240                                                   IIO_SHARED_BY_ALL,
1241                                                   &chan->info_mask_shared_by_all_available);
1242         if (ret < 0)
1243                 return ret;
1244         attrcount += ret;
1245
1246         if (chan->ext_info) {
1247                 unsigned int i = 0;
1248                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
1249                         ret = __iio_add_chan_devattr(ext_info->name,
1250                                         chan,
1251                                         ext_info->read ?
1252                                             &iio_read_channel_ext_info : NULL,
1253                                         ext_info->write ?
1254                                             &iio_write_channel_ext_info : NULL,
1255                                         i,
1256                                         ext_info->shared,
1257                                         &indio_dev->dev,
1258                                         &indio_dev->channel_attr_list);
1259                         i++;
1260                         if (ret == -EBUSY && ext_info->shared)
1261                                 continue;
1262
1263                         if (ret)
1264                                 return ret;
1265
1266                         attrcount++;
1267                 }
1268         }
1269
1270         return attrcount;
1271 }
1272
1273 /**
1274  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
1275  * @attr_list: List of IIO device attributes
1276  *
1277  * This function frees the memory allocated for each of the IIO device
1278  * attributes in the list.
1279  */
1280 void iio_free_chan_devattr_list(struct list_head *attr_list)
1281 {
1282         struct iio_dev_attr *p, *n;
1283
1284         list_for_each_entry_safe(p, n, attr_list, l) {
1285                 kfree(p->dev_attr.attr.name);
1286                 list_del(&p->l);
1287                 kfree(p);
1288         }
1289 }
1290
1291 static ssize_t iio_show_dev_name(struct device *dev,
1292                                  struct device_attribute *attr,
1293                                  char *buf)
1294 {
1295         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1296         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
1297 }
1298
1299 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
1300
1301 static ssize_t iio_show_dev_label(struct device *dev,
1302                                  struct device_attribute *attr,
1303                                  char *buf)
1304 {
1305         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1306         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->label);
1307 }
1308
1309 static DEVICE_ATTR(label, S_IRUGO, iio_show_dev_label, NULL);
1310
1311 static ssize_t iio_show_timestamp_clock(struct device *dev,
1312                                         struct device_attribute *attr,
1313                                         char *buf)
1314 {
1315         const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1316         const clockid_t clk = iio_device_get_clock(indio_dev);
1317         const char *name;
1318         ssize_t sz;
1319
1320         switch (clk) {
1321         case CLOCK_REALTIME:
1322                 name = "realtime\n";
1323                 sz = sizeof("realtime\n");
1324                 break;
1325         case CLOCK_MONOTONIC:
1326                 name = "monotonic\n";
1327                 sz = sizeof("monotonic\n");
1328                 break;
1329         case CLOCK_MONOTONIC_RAW:
1330                 name = "monotonic_raw\n";
1331                 sz = sizeof("monotonic_raw\n");
1332                 break;
1333         case CLOCK_REALTIME_COARSE:
1334                 name = "realtime_coarse\n";
1335                 sz = sizeof("realtime_coarse\n");
1336                 break;
1337         case CLOCK_MONOTONIC_COARSE:
1338                 name = "monotonic_coarse\n";
1339                 sz = sizeof("monotonic_coarse\n");
1340                 break;
1341         case CLOCK_BOOTTIME:
1342                 name = "boottime\n";
1343                 sz = sizeof("boottime\n");
1344                 break;
1345         case CLOCK_TAI:
1346                 name = "tai\n";
1347                 sz = sizeof("tai\n");
1348                 break;
1349         default:
1350                 BUG();
1351         }
1352
1353         memcpy(buf, name, sz);
1354         return sz;
1355 }
1356
1357 static ssize_t iio_store_timestamp_clock(struct device *dev,
1358                                          struct device_attribute *attr,
1359                                          const char *buf, size_t len)
1360 {
1361         clockid_t clk;
1362         int ret;
1363
1364         if (sysfs_streq(buf, "realtime"))
1365                 clk = CLOCK_REALTIME;
1366         else if (sysfs_streq(buf, "monotonic"))
1367                 clk = CLOCK_MONOTONIC;
1368         else if (sysfs_streq(buf, "monotonic_raw"))
1369                 clk = CLOCK_MONOTONIC_RAW;
1370         else if (sysfs_streq(buf, "realtime_coarse"))
1371                 clk = CLOCK_REALTIME_COARSE;
1372         else if (sysfs_streq(buf, "monotonic_coarse"))
1373                 clk = CLOCK_MONOTONIC_COARSE;
1374         else if (sysfs_streq(buf, "boottime"))
1375                 clk = CLOCK_BOOTTIME;
1376         else if (sysfs_streq(buf, "tai"))
1377                 clk = CLOCK_TAI;
1378         else
1379                 return -EINVAL;
1380
1381         ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
1382         if (ret)
1383                 return ret;
1384
1385         return len;
1386 }
1387
1388 static DEVICE_ATTR(current_timestamp_clock, S_IRUGO | S_IWUSR,
1389                    iio_show_timestamp_clock, iio_store_timestamp_clock);
1390
1391 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
1392 {
1393         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
1394         struct iio_dev_attr *p;
1395         struct attribute **attr, *clk = NULL;
1396
1397         /* First count elements in any existing group */
1398         if (indio_dev->info->attrs) {
1399                 attr = indio_dev->info->attrs->attrs;
1400                 while (*attr++ != NULL)
1401                         attrcount_orig++;
1402         }
1403         attrcount = attrcount_orig;
1404         /*
1405          * New channel registration method - relies on the fact a group does
1406          * not need to be initialized if its name is NULL.
1407          */
1408         if (indio_dev->channels)
1409                 for (i = 0; i < indio_dev->num_channels; i++) {
1410                         const struct iio_chan_spec *chan =
1411                                 &indio_dev->channels[i];
1412
1413                         if (chan->type == IIO_TIMESTAMP)
1414                                 clk = &dev_attr_current_timestamp_clock.attr;
1415
1416                         ret = iio_device_add_channel_sysfs(indio_dev, chan);
1417                         if (ret < 0)
1418                                 goto error_clear_attrs;
1419                         attrcount += ret;
1420                 }
1421
1422         if (indio_dev->event_interface)
1423                 clk = &dev_attr_current_timestamp_clock.attr;
1424
1425         if (indio_dev->name)
1426                 attrcount++;
1427         if (indio_dev->label)
1428                 attrcount++;
1429         if (clk)
1430                 attrcount++;
1431
1432         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
1433                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
1434                                                    GFP_KERNEL);
1435         if (indio_dev->chan_attr_group.attrs == NULL) {
1436                 ret = -ENOMEM;
1437                 goto error_clear_attrs;
1438         }
1439         /* Copy across original attributes */
1440         if (indio_dev->info->attrs)
1441                 memcpy(indio_dev->chan_attr_group.attrs,
1442                        indio_dev->info->attrs->attrs,
1443                        sizeof(indio_dev->chan_attr_group.attrs[0])
1444                        *attrcount_orig);
1445         attrn = attrcount_orig;
1446         /* Add all elements from the list. */
1447         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
1448                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
1449         if (indio_dev->name)
1450                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
1451         if (indio_dev->label)
1452                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_label.attr;
1453         if (clk)
1454                 indio_dev->chan_attr_group.attrs[attrn++] = clk;
1455
1456         indio_dev->groups[indio_dev->groupcounter++] =
1457                 &indio_dev->chan_attr_group;
1458
1459         return 0;
1460
1461 error_clear_attrs:
1462         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1463
1464         return ret;
1465 }
1466
1467 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
1468 {
1469
1470         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
1471         kfree(indio_dev->chan_attr_group.attrs);
1472         indio_dev->chan_attr_group.attrs = NULL;
1473 }
1474
1475 static void iio_dev_release(struct device *device)
1476 {
1477         struct iio_dev *indio_dev = dev_to_iio_dev(device);
1478         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1479                 iio_device_unregister_trigger_consumer(indio_dev);
1480         iio_device_unregister_eventset(indio_dev);
1481         iio_device_unregister_sysfs(indio_dev);
1482
1483         iio_buffer_put(indio_dev->buffer);
1484
1485         ida_simple_remove(&iio_ida, indio_dev->id);
1486         kfree(indio_dev);
1487 }
1488
1489 struct device_type iio_device_type = {
1490         .name = "iio_device",
1491         .release = iio_dev_release,
1492 };
1493
1494 /**
1495  * iio_device_alloc() - allocate an iio_dev from a driver
1496  * @sizeof_priv:        Space to allocate for private structure.
1497  **/
1498 struct iio_dev *iio_device_alloc(int sizeof_priv)
1499 {
1500         struct iio_dev *dev;
1501         size_t alloc_size;
1502
1503         alloc_size = sizeof(struct iio_dev);
1504         if (sizeof_priv) {
1505                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
1506                 alloc_size += sizeof_priv;
1507         }
1508         /* ensure 32-byte alignment of whole construct ? */
1509         alloc_size += IIO_ALIGN - 1;
1510
1511         dev = kzalloc(alloc_size, GFP_KERNEL);
1512         if (!dev)
1513                 return NULL;
1514
1515         dev->dev.groups = dev->groups;
1516         dev->dev.type = &iio_device_type;
1517         dev->dev.bus = &iio_bus_type;
1518         device_initialize(&dev->dev);
1519         dev_set_drvdata(&dev->dev, (void *)dev);
1520         mutex_init(&dev->mlock);
1521         mutex_init(&dev->info_exist_lock);
1522         INIT_LIST_HEAD(&dev->channel_attr_list);
1523
1524         dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
1525         if (dev->id < 0) {
1526                 /* cannot use a dev_err as the name isn't available */
1527                 pr_err("failed to get device id\n");
1528                 kfree(dev);
1529                 return NULL;
1530         }
1531         dev_set_name(&dev->dev, "iio:device%d", dev->id);
1532         INIT_LIST_HEAD(&dev->buffer_list);
1533
1534         return dev;
1535 }
1536 EXPORT_SYMBOL(iio_device_alloc);
1537
1538 /**
1539  * iio_device_free() - free an iio_dev from a driver
1540  * @dev:                the iio_dev associated with the device
1541  **/
1542 void iio_device_free(struct iio_dev *dev)
1543 {
1544         if (dev)
1545                 put_device(&dev->dev);
1546 }
1547 EXPORT_SYMBOL(iio_device_free);
1548
1549 static void devm_iio_device_release(struct device *dev, void *res)
1550 {
1551         iio_device_free(*(struct iio_dev **)res);
1552 }
1553
1554 /**
1555  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1556  * @dev:                Device to allocate iio_dev for
1557  * @sizeof_priv:        Space to allocate for private structure.
1558  *
1559  * Managed iio_device_alloc. iio_dev allocated with this function is
1560  * automatically freed on driver detach.
1561  *
1562  * RETURNS:
1563  * Pointer to allocated iio_dev on success, NULL on failure.
1564  */
1565 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1566 {
1567         struct iio_dev **ptr, *iio_dev;
1568
1569         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1570                            GFP_KERNEL);
1571         if (!ptr)
1572                 return NULL;
1573
1574         iio_dev = iio_device_alloc(sizeof_priv);
1575         if (iio_dev) {
1576                 *ptr = iio_dev;
1577                 devres_add(dev, ptr);
1578         } else {
1579                 devres_free(ptr);
1580         }
1581
1582         return iio_dev;
1583 }
1584 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1585
1586 /**
1587  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1588  * @inode:      Inode structure for identifying the device in the file system
1589  * @filp:       File structure for iio device used to keep and later access
1590  *              private data
1591  *
1592  * Return: 0 on success or -EBUSY if the device is already opened
1593  **/
1594 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1595 {
1596         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1597                                                 struct iio_dev, chrdev);
1598
1599         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1600                 return -EBUSY;
1601
1602         iio_device_get(indio_dev);
1603
1604         filp->private_data = indio_dev;
1605
1606         return 0;
1607 }
1608
1609 /**
1610  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1611  * @inode:      Inode structure pointer for the char device
1612  * @filp:       File structure pointer for the char device
1613  *
1614  * Return: 0 for successful release
1615  */
1616 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1617 {
1618         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1619                                                 struct iio_dev, chrdev);
1620         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1621         iio_device_put(indio_dev);
1622
1623         return 0;
1624 }
1625
1626 /* Somewhat of a cross file organization violation - ioctls here are actually
1627  * event related */
1628 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1629 {
1630         struct iio_dev *indio_dev = filp->private_data;
1631         int __user *ip = (int __user *)arg;
1632         int fd;
1633
1634         if (!indio_dev->info)
1635                 return -ENODEV;
1636
1637         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1638                 fd = iio_event_getfd(indio_dev);
1639                 if (fd < 0)
1640                         return fd;
1641                 if (copy_to_user(ip, &fd, sizeof(fd)))
1642                         return -EFAULT;
1643                 return 0;
1644         }
1645         return -EINVAL;
1646 }
1647
1648 static const struct file_operations iio_buffer_fileops = {
1649         .read = iio_buffer_read_outer_addr,
1650         .release = iio_chrdev_release,
1651         .open = iio_chrdev_open,
1652         .poll = iio_buffer_poll_addr,
1653         .owner = THIS_MODULE,
1654         .llseek = noop_llseek,
1655         .unlocked_ioctl = iio_ioctl,
1656         .compat_ioctl = compat_ptr_ioctl,
1657 };
1658
1659 static int iio_check_unique_scan_index(struct iio_dev *indio_dev)
1660 {
1661         int i, j;
1662         const struct iio_chan_spec *channels = indio_dev->channels;
1663
1664         if (!(indio_dev->modes & INDIO_ALL_BUFFER_MODES))
1665                 return 0;
1666
1667         for (i = 0; i < indio_dev->num_channels - 1; i++) {
1668                 if (channels[i].scan_index < 0)
1669                         continue;
1670                 for (j = i + 1; j < indio_dev->num_channels; j++)
1671                         if (channels[i].scan_index == channels[j].scan_index) {
1672                                 dev_err(&indio_dev->dev,
1673                                         "Duplicate scan index %d\n",
1674                                         channels[i].scan_index);
1675                                 return -EINVAL;
1676                         }
1677         }
1678
1679         return 0;
1680 }
1681
1682 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1683
1684 int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod)
1685 {
1686         int ret;
1687
1688         if (!indio_dev->info)
1689                 return -EINVAL;
1690
1691         indio_dev->driver_module = this_mod;
1692         /* If the calling driver did not initialize of_node, do it here */
1693         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1694                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1695
1696         indio_dev->label = of_get_property(indio_dev->dev.of_node, "label",
1697                                            NULL);
1698
1699         ret = iio_check_unique_scan_index(indio_dev);
1700         if (ret < 0)
1701                 return ret;
1702
1703         /* configure elements for the chrdev */
1704         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1705
1706         iio_device_register_debugfs(indio_dev);
1707
1708         ret = iio_buffer_alloc_sysfs_and_mask(indio_dev);
1709         if (ret) {
1710                 dev_err(indio_dev->dev.parent,
1711                         "Failed to create buffer sysfs interfaces\n");
1712                 goto error_unreg_debugfs;
1713         }
1714
1715         ret = iio_device_register_sysfs(indio_dev);
1716         if (ret) {
1717                 dev_err(indio_dev->dev.parent,
1718                         "Failed to register sysfs interfaces\n");
1719                 goto error_buffer_free_sysfs;
1720         }
1721         ret = iio_device_register_eventset(indio_dev);
1722         if (ret) {
1723                 dev_err(indio_dev->dev.parent,
1724                         "Failed to register event set\n");
1725                 goto error_free_sysfs;
1726         }
1727         if (indio_dev->modes & INDIO_ALL_TRIGGERED_MODES)
1728                 iio_device_register_trigger_consumer(indio_dev);
1729
1730         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1731                 indio_dev->setup_ops == NULL)
1732                 indio_dev->setup_ops = &noop_ring_setup_ops;
1733
1734         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1735
1736         indio_dev->chrdev.owner = this_mod;
1737
1738         ret = cdev_device_add(&indio_dev->chrdev, &indio_dev->dev);
1739         if (ret < 0)
1740                 goto error_unreg_eventset;
1741
1742         return 0;
1743
1744 error_unreg_eventset:
1745         iio_device_unregister_eventset(indio_dev);
1746 error_free_sysfs:
1747         iio_device_unregister_sysfs(indio_dev);
1748 error_buffer_free_sysfs:
1749         iio_buffer_free_sysfs_and_mask(indio_dev);
1750 error_unreg_debugfs:
1751         iio_device_unregister_debugfs(indio_dev);
1752         return ret;
1753 }
1754 EXPORT_SYMBOL(__iio_device_register);
1755
1756 /**
1757  * iio_device_unregister() - unregister a device from the IIO subsystem
1758  * @indio_dev:          Device structure representing the device.
1759  **/
1760 void iio_device_unregister(struct iio_dev *indio_dev)
1761 {
1762         cdev_device_del(&indio_dev->chrdev, &indio_dev->dev);
1763
1764         mutex_lock(&indio_dev->info_exist_lock);
1765
1766         iio_device_unregister_debugfs(indio_dev);
1767
1768         iio_disable_all_buffers(indio_dev);
1769
1770         indio_dev->info = NULL;
1771
1772         iio_device_wakeup_eventset(indio_dev);
1773         iio_buffer_wakeup_poll(indio_dev);
1774
1775         mutex_unlock(&indio_dev->info_exist_lock);
1776
1777         iio_buffer_free_sysfs_and_mask(indio_dev);
1778 }
1779 EXPORT_SYMBOL(iio_device_unregister);
1780
1781 static void devm_iio_device_unreg(struct device *dev, void *res)
1782 {
1783         iio_device_unregister(*(struct iio_dev **)res);
1784 }
1785
1786 int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
1787                                struct module *this_mod)
1788 {
1789         struct iio_dev **ptr;
1790         int ret;
1791
1792         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1793         if (!ptr)
1794                 return -ENOMEM;
1795
1796         *ptr = indio_dev;
1797         ret = __iio_device_register(indio_dev, this_mod);
1798         if (!ret)
1799                 devres_add(dev, ptr);
1800         else
1801                 devres_free(ptr);
1802
1803         return ret;
1804 }
1805 EXPORT_SYMBOL_GPL(__devm_iio_device_register);
1806
1807 /**
1808  * iio_device_claim_direct_mode - Keep device in direct mode
1809  * @indio_dev:  the iio_dev associated with the device
1810  *
1811  * If the device is in direct mode it is guaranteed to stay
1812  * that way until iio_device_release_direct_mode() is called.
1813  *
1814  * Use with iio_device_release_direct_mode()
1815  *
1816  * Returns: 0 on success, -EBUSY on failure
1817  */
1818 int iio_device_claim_direct_mode(struct iio_dev *indio_dev)
1819 {
1820         mutex_lock(&indio_dev->mlock);
1821
1822         if (iio_buffer_enabled(indio_dev)) {
1823                 mutex_unlock(&indio_dev->mlock);
1824                 return -EBUSY;
1825         }
1826         return 0;
1827 }
1828 EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
1829
1830 /**
1831  * iio_device_release_direct_mode - releases claim on direct mode
1832  * @indio_dev:  the iio_dev associated with the device
1833  *
1834  * Release the claim. Device is no longer guaranteed to stay
1835  * in direct mode.
1836  *
1837  * Use with iio_device_claim_direct_mode()
1838  */
1839 void iio_device_release_direct_mode(struct iio_dev *indio_dev)
1840 {
1841         mutex_unlock(&indio_dev->mlock);
1842 }
1843 EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
1844
1845 subsys_initcall(iio_init);
1846 module_exit(iio_exit);
1847
1848 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1849 MODULE_DESCRIPTION("Industrial I/O core");
1850 MODULE_LICENSE("GPL");