drivers/iio/industrialio-core.c

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