drivers/iio/industrialio-core.c

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