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