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