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