drivers/iio/industrialio-core.c

   1 /* The industrial I/O core
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * Based on elements of hwmon and input subsystems.
  10  */
  11
  12 #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 <linux/iio/iio.h>
  27 #include "iio_core.h"
  28 #include "iio_core_trigger.h"
  29 #include <linux/iio/sysfs.h>
  30 #include <linux/iio/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_direction[] = {
  46         [0] = "in",
  47         [1] = "out",
  48 };
  49
  50 static const char * const iio_chan_type_name_spec[] = {
  51         [IIO_VOLTAGE] = "voltage",
  52         [IIO_CURRENT] = "current",
  53         [IIO_POWER] = "power",
  54         [IIO_ACCEL] = "accel",
  55         [IIO_ANGL_VEL] = "anglvel",
  56         [IIO_MAGN] = "magn",
  57         [IIO_LIGHT] = "illuminance",
  58         [IIO_INTENSITY] = "intensity",
  59         [IIO_PROXIMITY] = "proximity",
  60         [IIO_TEMP] = "temp",
  61         [IIO_INCLI] = "incli",
  62         [IIO_ROT] = "rot",
  63         [IIO_ANGL] = "angl",
  64         [IIO_TIMESTAMP] = "timestamp",
  65         [IIO_CAPACITANCE] = "capacitance",
  66         [IIO_ALTVOLTAGE] = "altvoltage",
  67 };
  68
  69 static const char * const iio_modifier_names[] = {
  70         [IIO_MOD_X] = "x",
  71         [IIO_MOD_Y] = "y",
  72         [IIO_MOD_Z] = "z",
  73         [IIO_MOD_LIGHT_BOTH] = "both",
  74         [IIO_MOD_LIGHT_IR] = "ir",
  75 };
  76
  77 /* relies on pairs of these shared then separate */
  78 static const char * const iio_chan_info_postfix[] = {
  79         [IIO_CHAN_INFO_RAW] = "raw",
  80         [IIO_CHAN_INFO_PROCESSED] = "input",
  81         [IIO_CHAN_INFO_SCALE] = "scale",
  82         [IIO_CHAN_INFO_OFFSET] = "offset",
  83         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
  84         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
  85         [IIO_CHAN_INFO_PEAK] = "peak_raw",
  86         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
  87         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
  88         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
  89         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
  90         = "filter_low_pass_3db_frequency",
  91         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
  92         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
  93         [IIO_CHAN_INFO_PHASE] = "phase",
  94 };
  95
  96 const struct iio_chan_spec
  97 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
  98 {
  99         int i;
 100
 101         for (i = 0; i < indio_dev->num_channels; i++)
 102                 if (indio_dev->channels[i].scan_index == si)
 103                         return &indio_dev->channels[i];
 104         return NULL;
 105 }
 106
 107 /* This turns up an awful lot */
 108 ssize_t iio_read_const_attr(struct device *dev,
 109                             struct device_attribute *attr,
 110                             char *buf)
 111 {
 112         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 113 }
 114 EXPORT_SYMBOL(iio_read_const_attr);
 115
 116 static int __init iio_init(void)
 117 {
 118         int ret;
 119
 120         /* Register sysfs bus */
 121         ret  = bus_register(&iio_bus_type);
 122         if (ret < 0) {
 123                 printk(KERN_ERR
 124                        "%s could not register bus type\n",
 125                         __FILE__);
 126                 goto error_nothing;
 127         }
 128
 129         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 130         if (ret < 0) {
 131                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 132                        __FILE__);
 133                 goto error_unregister_bus_type;
 134         }
 135
 136         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 137
 138         return 0;
 139
 140 error_unregister_bus_type:
 141         bus_unregister(&iio_bus_type);
 142 error_nothing:
 143         return ret;
 144 }
 145
 146 static void __exit iio_exit(void)
 147 {
 148         if (iio_devt)
 149                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 150         bus_unregister(&iio_bus_type);
 151         debugfs_remove(iio_debugfs_dentry);
 152 }
 153
 154 #if defined(CONFIG_DEBUG_FS)
 155 static int iio_debugfs_open(struct inode *inode, struct file *file)
 156 {
 157         if (inode->i_private)
 158                 file->private_data = inode->i_private;
 159
 160         return 0;
 161 }
 162
 163 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 164                               size_t count, loff_t *ppos)
 165 {
 166         struct iio_dev *indio_dev = file->private_data;
 167         char buf[20];
 168         unsigned val = 0;
 169         ssize_t len;
 170         int ret;
 171
 172         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 173                                                   indio_dev->cached_reg_addr,
 174                                                   0, &val);
 175         if (ret)
 176                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 177
 178         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 179
 180         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 181 }
 182
 183 static ssize_t iio_debugfs_write_reg(struct file *file,
 184                      const char __user *userbuf, size_t count, loff_t *ppos)
 185 {
 186         struct iio_dev *indio_dev = file->private_data;
 187         unsigned reg, val;
 188         char buf[80];
 189         int ret;
 190
 191         count = min_t(size_t, count, (sizeof(buf)-1));
 192         if (copy_from_user(buf, userbuf, count))
 193                 return -EFAULT;
 194
 195         buf[count] = 0;
 196
 197         ret = sscanf(buf, "%i %i", &reg, &val);
 198
 199         switch (ret) {
 200         case 1:
 201                 indio_dev->cached_reg_addr = reg;
 202                 break;
 203         case 2:
 204                 indio_dev->cached_reg_addr = reg;
 205                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 206                                                           val, NULL);
 207                 if (ret) {
 208                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 209                                 __func__);
 210                         return ret;
 211                 }
 212                 break;
 213         default:
 214                 return -EINVAL;
 215         }
 216
 217         return count;
 218 }
 219
 220 static const struct file_operations iio_debugfs_reg_fops = {
 221         .open = iio_debugfs_open,
 222         .read = iio_debugfs_read_reg,
 223         .write = iio_debugfs_write_reg,
 224 };
 225
 226 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 227 {
 228         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 229 }
 230
 231 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 232 {
 233         struct dentry *d;
 234
 235         if (indio_dev->info->debugfs_reg_access == NULL)
 236                 return 0;
 237
 238         if (IS_ERR(iio_debugfs_dentry))
 239                 return 0;
 240
 241         indio_dev->debugfs_dentry =
 242                 debugfs_create_dir(dev_name(&indio_dev->dev),
 243                                    iio_debugfs_dentry);
 244         if (IS_ERR(indio_dev->debugfs_dentry))
 245                 return PTR_ERR(indio_dev->debugfs_dentry);
 246
 247         if (indio_dev->debugfs_dentry == NULL) {
 248                 dev_warn(indio_dev->dev.parent,
 249                          "Failed to create debugfs directory\n");
 250                 return -EFAULT;
 251         }
 252
 253         d = debugfs_create_file("direct_reg_access", 0644,
 254                                 indio_dev->debugfs_dentry,
 255                                 indio_dev, &iio_debugfs_reg_fops);
 256         if (!d) {
 257                 iio_device_unregister_debugfs(indio_dev);
 258                 return -ENOMEM;
 259         }
 260
 261         return 0;
 262 }
 263 #else
 264 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 265 {
 266         return 0;
 267 }
 268
 269 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 270 {
 271 }
 272 #endif /* CONFIG_DEBUG_FS */
 273
 274 static ssize_t iio_read_channel_ext_info(struct device *dev,
 275                                      struct device_attribute *attr,
 276                                      char *buf)
 277 {
 278         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 279         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 280         const struct iio_chan_spec_ext_info *ext_info;
 281
 282         ext_info = &this_attr->c->ext_info[this_attr->address];
 283
 284         return ext_info->read(indio_dev, this_attr->c, buf);
 285 }
 286
 287 static ssize_t iio_write_channel_ext_info(struct device *dev,
 288                                      struct device_attribute *attr,
 289                                      const char *buf,
 290                                          size_t len)
 291 {
 292         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 293         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 294         const struct iio_chan_spec_ext_info *ext_info;
 295
 296         ext_info = &this_attr->c->ext_info[this_attr->address];
 297
 298         return ext_info->write(indio_dev, this_attr->c, buf, len);
 299 }
 300
 301 static ssize_t iio_read_channel_info(struct device *dev,
 302                                      struct device_attribute *attr,
 303                                      char *buf)
 304 {
 305         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 306         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 307         int val, val2;
 308         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 309                                             &val, &val2, this_attr->address);
 310
 311         if (ret < 0)
 312                 return ret;
 313
 314         if (ret == IIO_VAL_INT)
 315                 return sprintf(buf, "%d\n", val);
 316         else if (ret == IIO_VAL_INT_PLUS_MICRO) {
 317                 if (val2 < 0)
 318                         return sprintf(buf, "-%d.%06u\n", val, -val2);
 319                 else
 320                         return sprintf(buf, "%d.%06u\n", val, val2);
 321         } else if (ret == IIO_VAL_INT_PLUS_NANO) {
 322                 if (val2 < 0)
 323                         return sprintf(buf, "-%d.%09u\n", val, -val2);
 324                 else
 325                         return sprintf(buf, "%d.%09u\n", val, val2);
 326         } else
 327                 return 0;
 328 }
 329
 330 static ssize_t iio_write_channel_info(struct device *dev,
 331                                       struct device_attribute *attr,
 332                                       const char *buf,
 333                                       size_t len)
 334 {
 335         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 336         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 337         int ret, integer = 0, fract = 0, fract_mult = 100000;
 338         bool integer_part = true, negative = false;
 339
 340         /* Assumes decimal - precision based on number of digits */
 341         if (!indio_dev->info->write_raw)
 342                 return -EINVAL;
 343
 344         if (indio_dev->info->write_raw_get_fmt)
 345                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 346                         this_attr->c, this_attr->address)) {
 347                 case IIO_VAL_INT_PLUS_MICRO:
 348                         fract_mult = 100000;
 349                         break;
 350                 case IIO_VAL_INT_PLUS_NANO:
 351                         fract_mult = 100000000;
 352                         break;
 353                 default:
 354                         return -EINVAL;
 355                 }
 356
 357         if (buf[0] == '-') {
 358                 negative = true;
 359                 buf++;
 360         }
 361
 362         while (*buf) {
 363                 if ('0' <= *buf && *buf <= '9') {
 364                         if (integer_part)
 365                                 integer = integer*10 + *buf - '0';
 366                         else {
 367                                 fract += fract_mult*(*buf - '0');
 368                                 if (fract_mult == 1)
 369                                         break;
 370                                 fract_mult /= 10;
 371                         }
 372                 } else if (*buf == '\n') {
 373                         if (*(buf + 1) == '\0')
 374                                 break;
 375                         else
 376                                 return -EINVAL;
 377                 } else if (*buf == '.') {
 378                         integer_part = false;
 379                 } else {
 380                         return -EINVAL;
 381                 }
 382                 buf++;
 383         }
 384         if (negative) {
 385                 if (integer)
 386                         integer = -integer;
 387                 else
 388                         fract = -fract;
 389         }
 390
 391         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 392                                          integer, fract, this_attr->address);
 393         if (ret)
 394                 return ret;
 395
 396         return len;
 397 }
 398
 399 static
 400 int __iio_device_attr_init(struct device_attribute *dev_attr,
 401                            const char *postfix,
 402                            struct iio_chan_spec const *chan,
 403                            ssize_t (*readfunc)(struct device *dev,
 404                                                struct device_attribute *attr,
 405                                                char *buf),
 406                            ssize_t (*writefunc)(struct device *dev,
 407                                                 struct device_attribute *attr,
 408                                                 const char *buf,
 409                                                 size_t len),
 410                            bool generic)
 411 {
 412         int ret;
 413         char *name_format, *full_postfix;
 414         sysfs_attr_init(&dev_attr->attr);
 415
 416         /* Build up postfix of <extend_name>_<modifier>_postfix */
 417         if (chan->modified && !generic) {
 418                 if (chan->extend_name)
 419                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 420                                                  iio_modifier_names[chan
 421                                                                     ->channel2],
 422                                                  chan->extend_name,
 423                                                  postfix);
 424                 else
 425                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 426                                                  iio_modifier_names[chan
 427                                                                     ->channel2],
 428                                                  postfix);
 429         } else {
 430                 if (chan->extend_name == NULL)
 431                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 432                 else
 433                         full_postfix = kasprintf(GFP_KERNEL,
 434                                                  "%s_%s",
 435                                                  chan->extend_name,
 436                                                  postfix);
 437         }
 438         if (full_postfix == NULL) {
 439                 ret = -ENOMEM;
 440                 goto error_ret;
 441         }
 442
 443         if (chan->differential) { /* Differential can not have modifier */
 444                 if (generic)
 445                         name_format
 446                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 447                                             iio_direction[chan->output],
 448                                             iio_chan_type_name_spec[chan->type],
 449                                             iio_chan_type_name_spec[chan->type],
 450                                             full_postfix);
 451                 else if (chan->indexed)
 452                         name_format
 453                                 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
 454                                             iio_direction[chan->output],
 455                                             iio_chan_type_name_spec[chan->type],
 456                                             chan->channel,
 457                                             iio_chan_type_name_spec[chan->type],
 458                                             chan->channel2,
 459                                             full_postfix);
 460                 else {
 461                         WARN_ON("Differential channels must be indexed\n");
 462                         ret = -EINVAL;
 463                         goto error_free_full_postfix;
 464                 }
 465         } else { /* Single ended */
 466                 if (generic)
 467                         name_format
 468                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 469                                             iio_direction[chan->output],
 470                                             iio_chan_type_name_spec[chan->type],
 471                                             full_postfix);
 472                 else if (chan->indexed)
 473                         name_format
 474                                 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 475                                             iio_direction[chan->output],
 476                                             iio_chan_type_name_spec[chan->type],
 477                                             chan->channel,
 478                                             full_postfix);
 479                 else
 480                         name_format
 481                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 482                                             iio_direction[chan->output],
 483                                             iio_chan_type_name_spec[chan->type],
 484                                             full_postfix);
 485         }
 486         if (name_format == NULL) {
 487                 ret = -ENOMEM;
 488                 goto error_free_full_postfix;
 489         }
 490         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 491                                         name_format,
 492                                         chan->channel,
 493                                         chan->channel2);
 494         if (dev_attr->attr.name == NULL) {
 495                 ret = -ENOMEM;
 496                 goto error_free_name_format;
 497         }
 498
 499         if (readfunc) {
 500                 dev_attr->attr.mode |= S_IRUGO;
 501                 dev_attr->show = readfunc;
 502         }
 503
 504         if (writefunc) {
 505                 dev_attr->attr.mode |= S_IWUSR;
 506                 dev_attr->store = writefunc;
 507         }
 508         kfree(name_format);
 509         kfree(full_postfix);
 510
 511         return 0;
 512
 513 error_free_name_format:
 514         kfree(name_format);
 515 error_free_full_postfix:
 516         kfree(full_postfix);
 517 error_ret:
 518         return ret;
 519 }
 520
 521 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 522 {
 523         kfree(dev_attr->attr.name);
 524 }
 525
 526 int __iio_add_chan_devattr(const char *postfix,
 527                            struct iio_chan_spec const *chan,
 528                            ssize_t (*readfunc)(struct device *dev,
 529                                                struct device_attribute *attr,
 530                                                char *buf),
 531                            ssize_t (*writefunc)(struct device *dev,
 532                                                 struct device_attribute *attr,
 533                                                 const char *buf,
 534                                                 size_t len),
 535                            u64 mask,
 536                            bool generic,
 537                            struct device *dev,
 538                            struct list_head *attr_list)
 539 {
 540         int ret;
 541         struct iio_dev_attr *iio_attr, *t;
 542
 543         iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
 544         if (iio_attr == NULL) {
 545                 ret = -ENOMEM;
 546                 goto error_ret;
 547         }
 548         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 549                                      postfix, chan,
 550                                      readfunc, writefunc, generic);
 551         if (ret)
 552                 goto error_iio_dev_attr_free;
 553         iio_attr->c = chan;
 554         iio_attr->address = mask;
 555         list_for_each_entry(t, attr_list, l)
 556                 if (strcmp(t->dev_attr.attr.name,
 557                            iio_attr->dev_attr.attr.name) == 0) {
 558                         if (!generic)
 559                                 dev_err(dev, "tried to double register : %s\n",
 560                                         t->dev_attr.attr.name);
 561                         ret = -EBUSY;
 562                         goto error_device_attr_deinit;
 563                 }
 564         list_add(&iio_attr->l, attr_list);
 565
 566         return 0;
 567
 568 error_device_attr_deinit:
 569         __iio_device_attr_deinit(&iio_attr->dev_attr);
 570 error_iio_dev_attr_free:
 571         kfree(iio_attr);
 572 error_ret:
 573         return ret;
 574 }
 575
 576 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 577                                         struct iio_chan_spec const *chan)
 578 {
 579         int ret, attrcount = 0;
 580         int i;
 581         const struct iio_chan_spec_ext_info *ext_info;
 582
 583         if (chan->channel < 0)
 584                 return 0;
 585         for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
 586                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
 587                                              chan,
 588                                              &iio_read_channel_info,
 589                                              &iio_write_channel_info,
 590                                              i/2,
 591                                              !(i%2),
 592                                              &indio_dev->dev,
 593                                              &indio_dev->channel_attr_list);
 594                 if (ret == -EBUSY && (i%2 == 0)) {
 595                         ret = 0;
 596                         continue;
 597                 }
 598                 if (ret < 0)
 599                         goto error_ret;
 600                 attrcount++;
 601         }
 602
 603         if (chan->ext_info) {
 604                 unsigned int i = 0;
 605                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 606                         ret = __iio_add_chan_devattr(ext_info->name,
 607                                         chan,
 608                                         ext_info->read ?
 609                                             &iio_read_channel_ext_info : NULL,
 610                                         ext_info->write ?
 611                                             &iio_write_channel_ext_info : NULL,
 612                                         i,
 613                                         ext_info->shared,
 614                                         &indio_dev->dev,
 615                                         &indio_dev->channel_attr_list);
 616                         i++;
 617                         if (ret == -EBUSY && ext_info->shared)
 618                                 continue;
 619
 620                         if (ret)
 621                                 goto error_ret;
 622
 623                         attrcount++;
 624                 }
 625         }
 626
 627         ret = attrcount;
 628 error_ret:
 629         return ret;
 630 }
 631
 632 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
 633                                                  struct iio_dev_attr *p)
 634 {
 635         kfree(p->dev_attr.attr.name);
 636         kfree(p);
 637 }
 638
 639 static ssize_t iio_show_dev_name(struct device *dev,
 640                                  struct device_attribute *attr,
 641                                  char *buf)
 642 {
 643         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 644         return sprintf(buf, "%s\n", indio_dev->name);
 645 }
 646
 647 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 648
 649 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 650 {
 651         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 652         struct iio_dev_attr *p, *n;
 653         struct attribute **attr;
 654
 655         /* First count elements in any existing group */
 656         if (indio_dev->info->attrs) {
 657                 attr = indio_dev->info->attrs->attrs;
 658                 while (*attr++ != NULL)
 659                         attrcount_orig++;
 660         }
 661         attrcount = attrcount_orig;
 662         /*
 663          * New channel registration method - relies on the fact a group does
 664          * not need to be initialized if it is name is NULL.
 665          */
 666         INIT_LIST_HEAD(&indio_dev->channel_attr_list);
 667         if (indio_dev->channels)
 668                 for (i = 0; i < indio_dev->num_channels; i++) {
 669                         ret = iio_device_add_channel_sysfs(indio_dev,
 670                                                            &indio_dev
 671                                                            ->channels[i]);
 672                         if (ret < 0)
 673                                 goto error_clear_attrs;
 674                         attrcount += ret;
 675                 }
 676
 677         if (indio_dev->name)
 678                 attrcount++;
 679
 680         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 681                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 682                                                    GFP_KERNEL);
 683         if (indio_dev->chan_attr_group.attrs == NULL) {
 684                 ret = -ENOMEM;
 685                 goto error_clear_attrs;
 686         }
 687         /* Copy across original attributes */
 688         if (indio_dev->info->attrs)
 689                 memcpy(indio_dev->chan_attr_group.attrs,
 690                        indio_dev->info->attrs->attrs,
 691                        sizeof(indio_dev->chan_attr_group.attrs[0])
 692                        *attrcount_orig);
 693         attrn = attrcount_orig;
 694         /* Add all elements from the list. */
 695         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 696                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 697         if (indio_dev->name)
 698                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 699
 700         indio_dev->groups[indio_dev->groupcounter++] =
 701                 &indio_dev->chan_attr_group;
 702
 703         return 0;
 704
 705 error_clear_attrs:
 706         list_for_each_entry_safe(p, n,
 707                                  &indio_dev->channel_attr_list, l) {
 708                 list_del(&p->l);
 709                 iio_device_remove_and_free_read_attr(indio_dev, p);
 710         }
 711
 712         return ret;
 713 }
 714
 715 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 716 {
 717
 718         struct iio_dev_attr *p, *n;
 719
 720         list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
 721                 list_del(&p->l);
 722                 iio_device_remove_and_free_read_attr(indio_dev, p);
 723         }
 724         kfree(indio_dev->chan_attr_group.attrs);
 725 }
 726
 727 static void iio_dev_release(struct device *device)
 728 {
 729         struct iio_dev *indio_dev = container_of(device, struct iio_dev, dev);
 730         cdev_del(&indio_dev->chrdev);
 731         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 732                 iio_device_unregister_trigger_consumer(indio_dev);
 733         iio_device_unregister_eventset(indio_dev);
 734         iio_device_unregister_sysfs(indio_dev);
 735         iio_device_unregister_debugfs(indio_dev);
 736 }
 737
 738 static struct device_type iio_dev_type = {
 739         .name = "iio_device",
 740         .release = iio_dev_release,
 741 };
 742
 743 struct iio_dev *iio_device_alloc(int sizeof_priv)
 744 {
 745         struct iio_dev *dev;
 746         size_t alloc_size;
 747
 748         alloc_size = sizeof(struct iio_dev);
 749         if (sizeof_priv) {
 750                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 751                 alloc_size += sizeof_priv;
 752         }
 753         /* ensure 32-byte alignment of whole construct ? */
 754         alloc_size += IIO_ALIGN - 1;
 755
 756         dev = kzalloc(alloc_size, GFP_KERNEL);
 757
 758         if (dev) {
 759                 dev->dev.groups = dev->groups;
 760                 dev->dev.type = &iio_dev_type;
 761                 dev->dev.bus = &iio_bus_type;
 762                 device_initialize(&dev->dev);
 763                 dev_set_drvdata(&dev->dev, (void *)dev);
 764                 mutex_init(&dev->mlock);
 765                 mutex_init(&dev->info_exist_lock);
 766
 767                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 768                 if (dev->id < 0) {
 769                         /* cannot use a dev_err as the name isn't available */
 770                         printk(KERN_ERR "Failed to get id\n");
 771                         kfree(dev);
 772                         return NULL;
 773                 }
 774                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 775         }
 776
 777         return dev;
 778 }
 779 EXPORT_SYMBOL(iio_device_alloc);
 780
 781 void iio_device_free(struct iio_dev *dev)
 782 {
 783         if (dev) {
 784                 ida_simple_remove(&iio_ida, dev->id);
 785                 kfree(dev);
 786         }
 787 }
 788 EXPORT_SYMBOL(iio_device_free);
 789
 790 /**
 791  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
 792  **/
 793 static int iio_chrdev_open(struct inode *inode, struct file *filp)
 794 {
 795         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 796                                                 struct iio_dev, chrdev);
 797
 798         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 799                 return -EBUSY;
 800
 801         filp->private_data = indio_dev;
 802
 803         return 0;
 804 }
 805
 806 /**
 807  * iio_chrdev_release() - chrdev file close buffer access and ioctls
 808  **/
 809 static int iio_chrdev_release(struct inode *inode, struct file *filp)
 810 {
 811         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 812                                                 struct iio_dev, chrdev);
 813         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
 814         return 0;
 815 }
 816
 817 /* Somewhat of a cross file organization violation - ioctls here are actually
 818  * event related */
 819 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 820 {
 821         struct iio_dev *indio_dev = filp->private_data;
 822         int __user *ip = (int __user *)arg;
 823         int fd;
 824
 825         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 826                 fd = iio_event_getfd(indio_dev);
 827                 if (copy_to_user(ip, &fd, sizeof(fd)))
 828                         return -EFAULT;
 829                 return 0;
 830         }
 831         return -EINVAL;
 832 }
 833
 834 static const struct file_operations iio_buffer_fileops = {
 835         .read = iio_buffer_read_first_n_outer_addr,
 836         .release = iio_chrdev_release,
 837         .open = iio_chrdev_open,
 838         .poll = iio_buffer_poll_addr,
 839         .owner = THIS_MODULE,
 840         .llseek = noop_llseek,
 841         .unlocked_ioctl = iio_ioctl,
 842         .compat_ioctl = iio_ioctl,
 843 };
 844
 845 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
 846
 847 int iio_device_register(struct iio_dev *indio_dev)
 848 {
 849         int ret;
 850
 851         /* configure elements for the chrdev */
 852         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
 853
 854         ret = iio_device_register_debugfs(indio_dev);
 855         if (ret) {
 856                 dev_err(indio_dev->dev.parent,
 857                         "Failed to register debugfs interfaces\n");
 858                 goto error_ret;
 859         }
 860         ret = iio_device_register_sysfs(indio_dev);
 861         if (ret) {
 862                 dev_err(indio_dev->dev.parent,
 863                         "Failed to register sysfs interfaces\n");
 864                 goto error_unreg_debugfs;
 865         }
 866         ret = iio_device_register_eventset(indio_dev);
 867         if (ret) {
 868                 dev_err(indio_dev->dev.parent,
 869                         "Failed to register event set\n");
 870                 goto error_free_sysfs;
 871         }
 872         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 873                 iio_device_register_trigger_consumer(indio_dev);
 874
 875         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
 876                 indio_dev->setup_ops == NULL)
 877                 indio_dev->setup_ops = &noop_ring_setup_ops;
 878
 879         ret = device_add(&indio_dev->dev);
 880         if (ret < 0)
 881                 goto error_unreg_eventset;
 882         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 883         indio_dev->chrdev.owner = indio_dev->info->driver_module;
 884         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 885         if (ret < 0)
 886                 goto error_del_device;
 887         return 0;
 888
 889 error_del_device:
 890         device_del(&indio_dev->dev);
 891 error_unreg_eventset:
 892         iio_device_unregister_eventset(indio_dev);
 893 error_free_sysfs:
 894         iio_device_unregister_sysfs(indio_dev);
 895 error_unreg_debugfs:
 896         iio_device_unregister_debugfs(indio_dev);
 897 error_ret:
 898         return ret;
 899 }
 900 EXPORT_SYMBOL(iio_device_register);
 901
 902 void iio_device_unregister(struct iio_dev *indio_dev)
 903 {
 904         mutex_lock(&indio_dev->info_exist_lock);
 905         indio_dev->info = NULL;
 906         mutex_unlock(&indio_dev->info_exist_lock);
 907         device_unregister(&indio_dev->dev);
 908 }
 909 EXPORT_SYMBOL(iio_device_unregister);
 910 subsys_initcall(iio_init);
 911 module_exit(iio_exit);
 912
 913 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 914 MODULE_DESCRIPTION("Industrial I/O core");
 915 MODULE_LICENSE("GPL");