drivers/staging/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 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/idr.h>
  15 #include <linux/kdev_t.h>
  16 #include <linux/err.h>
  17 #include <linux/device.h>
  18 #include <linux/fs.h>
  19 #include <linux/poll.h>
  20 #include <linux/sched.h>
  21 #include <linux/wait.h>
  22 #include <linux/cdev.h>
  23 #include <linux/slab.h>
  24 #include <linux/anon_inodes.h>
  25 #include <linux/debugfs.h>
  26 #include "iio.h"
  27 #include "iio_core.h"
  28 #include "iio_core_trigger.h"
  29 #include "sysfs.h"
  30 #include "events.h"
  31
  32 /* IDA to assign each registered device a unique id*/
  33 static DEFINE_IDA(iio_ida);
  34
  35 static dev_t iio_devt;
  36
  37 #define IIO_DEV_MAX 256
  38 struct bus_type iio_bus_type = {
  39         .name = "iio",
  40 };
  41 EXPORT_SYMBOL(iio_bus_type);
  42
  43 static struct dentry *iio_debugfs_dentry;
  44
  45 static const char * const iio_data_type_name[] = {
  46         [IIO_RAW] = "raw",
  47         [IIO_PROCESSED] = "input",
  48 };
  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 };
  72
  73 static const char * const iio_modifier_names[] = {
  74         [IIO_MOD_X] = "x",
  75         [IIO_MOD_Y] = "y",
  76         [IIO_MOD_Z] = "z",
  77         [IIO_MOD_LIGHT_BOTH] = "both",
  78         [IIO_MOD_LIGHT_IR] = "ir",
  79 };
  80
  81 /* relies on pairs of these shared then separate */
  82 static const char * const iio_chan_info_postfix[] = {
  83         [IIO_CHAN_INFO_SCALE] = "scale",
  84         [IIO_CHAN_INFO_OFFSET] = "offset",
  85         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
  86         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
  87         [IIO_CHAN_INFO_PEAK] = "peak_raw",
  88         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
  89         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
  90         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
  91         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
  92         = "filter_low_pass_3db_frequency",
  93 };
  94
  95 const struct iio_chan_spec
  96 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
  97 {
  98         int i;
  99
 100         for (i = 0; i < indio_dev->num_channels; i++)
 101                 if (indio_dev->channels[i].scan_index == si)
 102                         return &indio_dev->channels[i];
 103         return NULL;
 104 }
 105
 106 /* This turns up an awful lot */
 107 ssize_t iio_read_const_attr(struct device *dev,
 108                             struct device_attribute *attr,
 109                             char *buf)
 110 {
 111         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 112 }
 113 EXPORT_SYMBOL(iio_read_const_attr);
 114
 115 static int __init iio_init(void)
 116 {
 117         int ret;
 118
 119         /* Register sysfs bus */
 120         ret  = bus_register(&iio_bus_type);
 121         if (ret < 0) {
 122                 printk(KERN_ERR
 123                        "%s could not register bus type\n",
 124                         __FILE__);
 125                 goto error_nothing;
 126         }
 127
 128         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 129         if (ret < 0) {
 130                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 131                        __FILE__);
 132                 goto error_unregister_bus_type;
 133         }
 134
 135         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 136
 137         return 0;
 138
 139 error_unregister_bus_type:
 140         bus_unregister(&iio_bus_type);
 141 error_nothing:
 142         return ret;
 143 }
 144
 145 static void __exit iio_exit(void)
 146 {
 147         if (iio_devt)
 148                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 149         bus_unregister(&iio_bus_type);
 150         debugfs_remove(iio_debugfs_dentry);
 151 }
 152
 153 #if defined(CONFIG_DEBUG_FS)
 154 static int iio_debugfs_open(struct inode *inode, struct file *file)
 155 {
 156         if (inode->i_private)
 157                 file->private_data = inode->i_private;
 158
 159         return 0;
 160 }
 161
 162 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 163                               size_t count, loff_t *ppos)
 164 {
 165         struct iio_dev *indio_dev = file->private_data;
 166         char buf[20];
 167         unsigned val = 0;
 168         ssize_t len;
 169         int ret;
 170
 171         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 172                                                   indio_dev->cached_reg_addr,
 173                                                   0, &val);
 174         if (ret)
 175                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 176
 177         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 178
 179         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 180 }
 181
 182 static ssize_t iio_debugfs_write_reg(struct file *file,
 183                      const char __user *userbuf, size_t count, loff_t *ppos)
 184 {
 185         struct iio_dev *indio_dev = file->private_data;
 186         unsigned reg, val;
 187         char buf[80];
 188         int ret;
 189
 190         count = min_t(size_t, count, (sizeof(buf)-1));
 191         if (copy_from_user(buf, userbuf, count))
 192                 return -EFAULT;
 193
 194         buf[count] = 0;
 195
 196         ret = sscanf(buf, "%i %i", &reg, &val);
 197
 198         switch (ret) {
 199         case 1:
 200                 indio_dev->cached_reg_addr = reg;
 201                 break;
 202         case 2:
 203                 indio_dev->cached_reg_addr = reg;
 204                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 205                                                           val, NULL);
 206                 if (ret) {
 207                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 208                                 __func__);
 209                         return ret;
 210                 }
 211                 break;
 212         default:
 213                 return -EINVAL;
 214         }
 215
 216         return count;
 217 }
 218
 219 static const struct file_operations iio_debugfs_reg_fops = {
 220         .open = iio_debugfs_open,
 221         .read = iio_debugfs_read_reg,
 222         .write = iio_debugfs_write_reg,
 223 };
 224
 225 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 226 {
 227         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 228 }
 229
 230 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 231 {
 232         struct dentry *d;
 233
 234         if (indio_dev->info->debugfs_reg_access == NULL)
 235                 return 0;
 236
 237         if (IS_ERR(iio_debugfs_dentry))
 238                 return 0;
 239
 240         indio_dev->debugfs_dentry =
 241                 debugfs_create_dir(dev_name(&indio_dev->dev),
 242                                    iio_debugfs_dentry);
 243         if (IS_ERR(indio_dev->debugfs_dentry))
 244                 return PTR_ERR(indio_dev->debugfs_dentry);
 245
 246         if (indio_dev->debugfs_dentry == NULL) {
 247                 dev_warn(indio_dev->dev.parent,
 248                          "Failed to create debugfs directory\n");
 249                 return -EFAULT;
 250         }
 251
 252         d = debugfs_create_file("direct_reg_access", 0644,
 253                                 indio_dev->debugfs_dentry,
 254                                 indio_dev, &iio_debugfs_reg_fops);
 255         if (!d) {
 256                 iio_device_unregister_debugfs(indio_dev);
 257                 return -ENOMEM;
 258         }
 259
 260         return 0;
 261 }
 262 #else
 263 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 264 {
 265         return 0;
 266 }
 267
 268 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 269 {
 270 }
 271 #endif /* CONFIG_DEBUG_FS */
 272
 273 static ssize_t iio_read_channel_ext_info(struct device *dev,
 274                                      struct device_attribute *attr,
 275                                      char *buf)
 276 {
 277         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 278         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 279         const struct iio_chan_spec_ext_info *ext_info;
 280
 281         ext_info = &this_attr->c->ext_info[this_attr->address];
 282
 283         return ext_info->read(indio_dev, this_attr->c, buf);
 284 }
 285
 286 static ssize_t iio_write_channel_ext_info(struct device *dev,
 287                                      struct device_attribute *attr,
 288                                      const char *buf,
 289                                          size_t len)
 290 {
 291         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 292         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 293         const struct iio_chan_spec_ext_info *ext_info;
 294
 295         ext_info = &this_attr->c->ext_info[this_attr->address];
 296
 297         return ext_info->write(indio_dev, this_attr->c, buf, len);
 298 }
 299
 300 static ssize_t iio_read_channel_info(struct device *dev,
 301                                      struct device_attribute *attr,
 302                                      char *buf)
 303 {
 304         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 305         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 306         int val, val2;
 307         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 308                                             &val, &val2, this_attr->address);
 309
 310         if (ret < 0)
 311                 return ret;
 312
 313         if (ret == IIO_VAL_INT)
 314                 return sprintf(buf, "%d\n", val);
 315         else if (ret == IIO_VAL_INT_PLUS_MICRO) {
 316                 if (val2 < 0)
 317                         return sprintf(buf, "-%d.%06u\n", val, -val2);
 318                 else
 319                         return sprintf(buf, "%d.%06u\n", val, val2);
 320         } else if (ret == IIO_VAL_INT_PLUS_NANO) {
 321                 if (val2 < 0)
 322                         return sprintf(buf, "-%d.%09u\n", val, -val2);
 323                 else
 324                         return sprintf(buf, "%d.%09u\n", val, val2);
 325         } else
 326                 return 0;
 327 }
 328
 329 static ssize_t iio_write_channel_info(struct device *dev,
 330                                       struct device_attribute *attr,
 331                                       const char *buf,
 332                                       size_t len)
 333 {
 334         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 335         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 336         int ret, integer = 0, fract = 0, fract_mult = 100000;
 337         bool integer_part = true, negative = false;
 338
 339         /* Assumes decimal - precision based on number of digits */
 340         if (!indio_dev->info->write_raw)
 341                 return -EINVAL;
 342
 343         if (indio_dev->info->write_raw_get_fmt)
 344                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 345                         this_attr->c, this_attr->address)) {
 346                 case IIO_VAL_INT_PLUS_MICRO:
 347                         fract_mult = 100000;
 348                         break;
 349                 case IIO_VAL_INT_PLUS_NANO:
 350                         fract_mult = 100000000;
 351                         break;
 352                 default:
 353                         return -EINVAL;
 354                 }
 355
 356         if (buf[0] == '-') {
 357                 negative = true;
 358                 buf++;
 359         }
 360
 361         while (*buf) {
 362                 if ('0' <= *buf && *buf <= '9') {
 363                         if (integer_part)
 364                                 integer = integer*10 + *buf - '0';
 365                         else {
 366                                 fract += fract_mult*(*buf - '0');
 367                                 if (fract_mult == 1)
 368                                         break;
 369                                 fract_mult /= 10;
 370                         }
 371                 } else if (*buf == '\n') {
 372                         if (*(buf + 1) == '\0')
 373                                 break;
 374                         else
 375                                 return -EINVAL;
 376                 } else if (*buf == '.') {
 377                         integer_part = false;
 378                 } else {
 379                         return -EINVAL;
 380                 }
 381                 buf++;
 382         }
 383         if (negative) {
 384                 if (integer)
 385                         integer = -integer;
 386                 else
 387                         fract = -fract;
 388         }
 389
 390         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 391                                          integer, fract, this_attr->address);
 392         if (ret)
 393                 return ret;
 394
 395         return len;
 396 }
 397
 398 static
 399 int __iio_device_attr_init(struct device_attribute *dev_attr,
 400                            const char *postfix,
 401                            struct iio_chan_spec const *chan,
 402                            ssize_t (*readfunc)(struct device *dev,
 403                                                struct device_attribute *attr,
 404                                                char *buf),
 405                            ssize_t (*writefunc)(struct device *dev,
 406                                                 struct device_attribute *attr,
 407                                                 const char *buf,
 408                                                 size_t len),
 409                            bool generic)
 410 {
 411         int ret;
 412         char *name_format, *full_postfix;
 413         sysfs_attr_init(&dev_attr->attr);
 414
 415         /* Build up postfix of <extend_name>_<modifier>_postfix */
 416         if (chan->modified && !generic) {
 417                 if (chan->extend_name)
 418                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 419                                                  iio_modifier_names[chan
 420                                                                     ->channel2],
 421                                                  chan->extend_name,
 422                                                  postfix);
 423                 else
 424                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 425                                                  iio_modifier_names[chan
 426                                                                     ->channel2],
 427                                                  postfix);
 428         } else {
 429                 if (chan->extend_name == NULL)
 430                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 431                 else
 432                         full_postfix = kasprintf(GFP_KERNEL,
 433                                                  "%s_%s",
 434                                                  chan->extend_name,
 435                                                  postfix);
 436         }
 437         if (full_postfix == NULL) {
 438                 ret = -ENOMEM;
 439                 goto error_ret;
 440         }
 441
 442         if (chan->differential) { /* Differential can not have modifier */
 443                 if (generic)
 444                         name_format
 445                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 446                                             iio_direction[chan->output],
 447                                             iio_chan_type_name_spec[chan->type],
 448                                             iio_chan_type_name_spec[chan->type],
 449                                             full_postfix);
 450                 else if (chan->indexed)
 451                         name_format
 452                                 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
 453                                             iio_direction[chan->output],
 454                                             iio_chan_type_name_spec[chan->type],
 455                                             chan->channel,
 456                                             iio_chan_type_name_spec[chan->type],
 457                                             chan->channel2,
 458                                             full_postfix);
 459                 else {
 460                         WARN_ON("Differential channels must be indexed\n");
 461                         ret = -EINVAL;
 462                         goto error_free_full_postfix;
 463                 }
 464         } else { /* Single ended */
 465                 if (generic)
 466                         name_format
 467                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 468                                             iio_direction[chan->output],
 469                                             iio_chan_type_name_spec[chan->type],
 470                                             full_postfix);
 471                 else if (chan->indexed)
 472                         name_format
 473                                 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 474                                             iio_direction[chan->output],
 475                                             iio_chan_type_name_spec[chan->type],
 476                                             chan->channel,
 477                                             full_postfix);
 478                 else
 479                         name_format
 480                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 481                                             iio_direction[chan->output],
 482                                             iio_chan_type_name_spec[chan->type],
 483                                             full_postfix);
 484         }
 485         if (name_format == NULL) {
 486                 ret = -ENOMEM;
 487                 goto error_free_full_postfix;
 488         }
 489         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 490                                         name_format,
 491                                         chan->channel,
 492                                         chan->channel2);
 493         if (dev_attr->attr.name == NULL) {
 494                 ret = -ENOMEM;
 495                 goto error_free_name_format;
 496         }
 497
 498         if (readfunc) {
 499                 dev_attr->attr.mode |= S_IRUGO;
 500                 dev_attr->show = readfunc;
 501         }
 502
 503         if (writefunc) {
 504                 dev_attr->attr.mode |= S_IWUSR;
 505                 dev_attr->store = writefunc;
 506         }
 507         kfree(name_format);
 508         kfree(full_postfix);
 509
 510         return 0;
 511
 512 error_free_name_format:
 513         kfree(name_format);
 514 error_free_full_postfix:
 515         kfree(full_postfix);
 516 error_ret:
 517         return ret;
 518 }
 519
 520 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 521 {
 522         kfree(dev_attr->attr.name);
 523 }
 524
 525 int __iio_add_chan_devattr(const char *postfix,
 526                            struct iio_chan_spec const *chan,
 527                            ssize_t (*readfunc)(struct device *dev,
 528                                                struct device_attribute *attr,
 529                                                char *buf),
 530                            ssize_t (*writefunc)(struct device *dev,
 531                                                 struct device_attribute *attr,
 532                                                 const char *buf,
 533                                                 size_t len),
 534                            u64 mask,
 535                            bool generic,
 536                            struct device *dev,
 537                            struct list_head *attr_list)
 538 {
 539         int ret;
 540         struct iio_dev_attr *iio_attr, *t;
 541
 542         iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
 543         if (iio_attr == NULL) {
 544                 ret = -ENOMEM;
 545                 goto error_ret;
 546         }
 547         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 548                                      postfix, chan,
 549                                      readfunc, writefunc, generic);
 550         if (ret)
 551                 goto error_iio_dev_attr_free;
 552         iio_attr->c = chan;
 553         iio_attr->address = mask;
 554         list_for_each_entry(t, attr_list, l)
 555                 if (strcmp(t->dev_attr.attr.name,
 556                            iio_attr->dev_attr.attr.name) == 0) {
 557                         if (!generic)
 558                                 dev_err(dev, "tried to double register : %s\n",
 559                                         t->dev_attr.attr.name);
 560                         ret = -EBUSY;
 561                         goto error_device_attr_deinit;
 562                 }
 563         list_add(&iio_attr->l, attr_list);
 564
 565         return 0;
 566
 567 error_device_attr_deinit:
 568         __iio_device_attr_deinit(&iio_attr->dev_attr);
 569 error_iio_dev_attr_free:
 570         kfree(iio_attr);
 571 error_ret:
 572         return ret;
 573 }
 574
 575 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 576                                         struct iio_chan_spec const *chan)
 577 {
 578         int ret, i, attrcount = 0;
 579         const struct iio_chan_spec_ext_info *ext_info;
 580
 581         if (chan->channel < 0)
 582                 return 0;
 583
 584         ret = __iio_add_chan_devattr(iio_data_type_name[chan->processed_val],
 585                                      chan,
 586                                      &iio_read_channel_info,
 587                                      (chan->output ?
 588                                       &iio_write_channel_info : NULL),
 589                                      0,
 590                                      0,
 591                                      &indio_dev->dev,
 592                                      &indio_dev->channel_attr_list);
 593         if (ret)
 594                 goto error_ret;
 595         attrcount++;
 596
 597         for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
 598                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
 599                                              chan,
 600                                              &iio_read_channel_info,
 601                                              &iio_write_channel_info,
 602                                              i/2,
 603                                              !(i%2),
 604                                              &indio_dev->dev,
 605                                              &indio_dev->channel_attr_list);
 606                 if (ret == -EBUSY && (i%2 == 0)) {
 607                         ret = 0;
 608                         continue;
 609                 }
 610                 if (ret < 0)
 611                         goto error_ret;
 612                 attrcount++;
 613         }
 614
 615         if (chan->ext_info) {
 616                 unsigned int i = 0;
 617                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 618                         ret = __iio_add_chan_devattr(ext_info->name,
 619                                         chan,
 620                                         ext_info->read ?
 621                                             &iio_read_channel_ext_info : NULL,
 622                                         ext_info->write ?
 623                                             &iio_write_channel_ext_info : NULL,
 624                                         i,
 625                                         ext_info->shared,
 626                                         &indio_dev->dev,
 627                                         &indio_dev->channel_attr_list);
 628                         i++;
 629                         if (ret == -EBUSY && ext_info->shared)
 630                                 continue;
 631
 632                         if (ret)
 633                                 goto error_ret;
 634
 635                         attrcount++;
 636                 }
 637         }
 638
 639         ret = attrcount;
 640 error_ret:
 641         return ret;
 642 }
 643
 644 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
 645                                                  struct iio_dev_attr *p)
 646 {
 647         kfree(p->dev_attr.attr.name);
 648         kfree(p);
 649 }
 650
 651 static ssize_t iio_show_dev_name(struct device *dev,
 652                                  struct device_attribute *attr,
 653                                  char *buf)
 654 {
 655         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 656         return sprintf(buf, "%s\n", indio_dev->name);
 657 }
 658
 659 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 660
 661 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 662 {
 663         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 664         struct iio_dev_attr *p, *n;
 665         struct attribute **attr;
 666
 667         /* First count elements in any existing group */
 668         if (indio_dev->info->attrs) {
 669                 attr = indio_dev->info->attrs->attrs;
 670                 while (*attr++ != NULL)
 671                         attrcount_orig++;
 672         }
 673         attrcount = attrcount_orig;
 674         /*
 675          * New channel registration method - relies on the fact a group does
 676          * not need to be initialized if it is name is NULL.
 677          */
 678         INIT_LIST_HEAD(&indio_dev->channel_attr_list);
 679         if (indio_dev->channels)
 680                 for (i = 0; i < indio_dev->num_channels; i++) {
 681                         ret = iio_device_add_channel_sysfs(indio_dev,
 682                                                            &indio_dev
 683                                                            ->channels[i]);
 684                         if (ret < 0)
 685                                 goto error_clear_attrs;
 686                         attrcount += ret;
 687                 }
 688
 689         if (indio_dev->name)
 690                 attrcount++;
 691
 692         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 693                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 694                                                    GFP_KERNEL);
 695         if (indio_dev->chan_attr_group.attrs == NULL) {
 696                 ret = -ENOMEM;
 697                 goto error_clear_attrs;
 698         }
 699         /* Copy across original attributes */
 700         if (indio_dev->info->attrs)
 701                 memcpy(indio_dev->chan_attr_group.attrs,
 702                        indio_dev->info->attrs->attrs,
 703                        sizeof(indio_dev->chan_attr_group.attrs[0])
 704                        *attrcount_orig);
 705         attrn = attrcount_orig;
 706         /* Add all elements from the list. */
 707         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 708                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 709         if (indio_dev->name)
 710                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 711
 712         indio_dev->groups[indio_dev->groupcounter++] =
 713                 &indio_dev->chan_attr_group;
 714
 715         return 0;
 716
 717 error_clear_attrs:
 718         list_for_each_entry_safe(p, n,
 719                                  &indio_dev->channel_attr_list, l) {
 720                 list_del(&p->l);
 721                 iio_device_remove_and_free_read_attr(indio_dev, p);
 722         }
 723
 724         return ret;
 725 }
 726
 727 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 728 {
 729
 730         struct iio_dev_attr *p, *n;
 731
 732         list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
 733                 list_del(&p->l);
 734                 iio_device_remove_and_free_read_attr(indio_dev, p);
 735         }
 736         kfree(indio_dev->chan_attr_group.attrs);
 737 }
 738
 739 static void iio_dev_release(struct device *device)
 740 {
 741         struct iio_dev *indio_dev = container_of(device, struct iio_dev, dev);
 742         cdev_del(&indio_dev->chrdev);
 743         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 744                 iio_device_unregister_trigger_consumer(indio_dev);
 745         iio_device_unregister_eventset(indio_dev);
 746         iio_device_unregister_sysfs(indio_dev);
 747         iio_device_unregister_debugfs(indio_dev);
 748 }
 749
 750 static struct device_type iio_dev_type = {
 751         .name = "iio_device",
 752         .release = iio_dev_release,
 753 };
 754
 755 struct iio_dev *iio_allocate_device(int sizeof_priv)
 756 {
 757         struct iio_dev *dev;
 758         size_t alloc_size;
 759
 760         alloc_size = sizeof(struct iio_dev);
 761         if (sizeof_priv) {
 762                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 763                 alloc_size += sizeof_priv;
 764         }
 765         /* ensure 32-byte alignment of whole construct ? */
 766         alloc_size += IIO_ALIGN - 1;
 767
 768         dev = kzalloc(alloc_size, GFP_KERNEL);
 769
 770         if (dev) {
 771                 dev->dev.groups = dev->groups;
 772                 dev->dev.type = &iio_dev_type;
 773                 dev->dev.bus = &iio_bus_type;
 774                 device_initialize(&dev->dev);
 775                 dev_set_drvdata(&dev->dev, (void *)dev);
 776                 mutex_init(&dev->mlock);
 777                 mutex_init(&dev->info_exist_lock);
 778
 779                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 780                 if (dev->id < 0) {
 781                         /* cannot use a dev_err as the name isn't available */
 782                         printk(KERN_ERR "Failed to get id\n");
 783                         kfree(dev);
 784                         return NULL;
 785                 }
 786                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 787         }
 788
 789         return dev;
 790 }
 791 EXPORT_SYMBOL(iio_allocate_device);
 792
 793 void iio_free_device(struct iio_dev *dev)
 794 {
 795         if (dev) {
 796                 ida_simple_remove(&iio_ida, dev->id);
 797                 kfree(dev);
 798         }
 799 }
 800 EXPORT_SYMBOL(iio_free_device);
 801
 802 /**
 803  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
 804  **/
 805 static int iio_chrdev_open(struct inode *inode, struct file *filp)
 806 {
 807         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 808                                                 struct iio_dev, chrdev);
 809
 810         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 811                 return -EBUSY;
 812
 813         filp->private_data = indio_dev;
 814
 815         return 0;
 816 }
 817
 818 /**
 819  * iio_chrdev_release() - chrdev file close buffer access and ioctls
 820  **/
 821 static int iio_chrdev_release(struct inode *inode, struct file *filp)
 822 {
 823         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 824                                                 struct iio_dev, chrdev);
 825         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
 826         return 0;
 827 }
 828
 829 /* Somewhat of a cross file organization violation - ioctls here are actually
 830  * event related */
 831 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 832 {
 833         struct iio_dev *indio_dev = filp->private_data;
 834         int __user *ip = (int __user *)arg;
 835         int fd;
 836
 837         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 838                 fd = iio_event_getfd(indio_dev);
 839                 if (copy_to_user(ip, &fd, sizeof(fd)))
 840                         return -EFAULT;
 841                 return 0;
 842         }
 843         return -EINVAL;
 844 }
 845
 846 static const struct file_operations iio_buffer_fileops = {
 847         .read = iio_buffer_read_first_n_outer_addr,
 848         .release = iio_chrdev_release,
 849         .open = iio_chrdev_open,
 850         .poll = iio_buffer_poll_addr,
 851         .owner = THIS_MODULE,
 852         .llseek = noop_llseek,
 853         .unlocked_ioctl = iio_ioctl,
 854         .compat_ioctl = iio_ioctl,
 855 };
 856
 857 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
 858
 859 int iio_device_register(struct iio_dev *indio_dev)
 860 {
 861         int ret;
 862
 863         /* configure elements for the chrdev */
 864         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
 865
 866         ret = iio_device_register_debugfs(indio_dev);
 867         if (ret) {
 868                 dev_err(indio_dev->dev.parent,
 869                         "Failed to register debugfs interfaces\n");
 870                 goto error_ret;
 871         }
 872         ret = iio_device_register_sysfs(indio_dev);
 873         if (ret) {
 874                 dev_err(indio_dev->dev.parent,
 875                         "Failed to register sysfs interfaces\n");
 876                 goto error_unreg_debugfs;
 877         }
 878         ret = iio_device_register_eventset(indio_dev);
 879         if (ret) {
 880                 dev_err(indio_dev->dev.parent,
 881                         "Failed to register event set\n");
 882                 goto error_free_sysfs;
 883         }
 884         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 885                 iio_device_register_trigger_consumer(indio_dev);
 886
 887         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
 888                 indio_dev->setup_ops == NULL)
 889                 indio_dev->setup_ops = &noop_ring_setup_ops;
 890
 891         ret = device_add(&indio_dev->dev);
 892         if (ret < 0)
 893                 goto error_unreg_eventset;
 894         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 895         indio_dev->chrdev.owner = indio_dev->info->driver_module;
 896         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 897         if (ret < 0)
 898                 goto error_del_device;
 899         return 0;
 900
 901 error_del_device:
 902         device_del(&indio_dev->dev);
 903 error_unreg_eventset:
 904         iio_device_unregister_eventset(indio_dev);
 905 error_free_sysfs:
 906         iio_device_unregister_sysfs(indio_dev);
 907 error_unreg_debugfs:
 908         iio_device_unregister_debugfs(indio_dev);
 909 error_ret:
 910         return ret;
 911 }
 912 EXPORT_SYMBOL(iio_device_register);
 913
 914 void iio_device_unregister(struct iio_dev *indio_dev)
 915 {
 916         mutex_lock(&indio_dev->info_exist_lock);
 917         indio_dev->info = NULL;
 918         mutex_unlock(&indio_dev->info_exist_lock);
 919         device_unregister(&indio_dev->dev);
 920 }
 921 EXPORT_SYMBOL(iio_device_unregister);
 922 subsys_initcall(iio_init);
 923 module_exit(iio_exit);
 924
 925 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 926 MODULE_DESCRIPTION("Industrial I/O core");
 927 MODULE_LICENSE("GPL");