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         [IIO_CCT] = "cct",
  68 };
  69
  70 static const char * const iio_modifier_names[] = {
  71         [IIO_MOD_X] = "x",
  72         [IIO_MOD_Y] = "y",
  73         [IIO_MOD_Z] = "z",
  74         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
  75         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
  76         [IIO_MOD_LIGHT_BOTH] = "both",
  77         [IIO_MOD_LIGHT_IR] = "ir",
  78         [IIO_MOD_LIGHT_CLEAR] = "clear",
  79         [IIO_MOD_LIGHT_RED] = "red",
  80         [IIO_MOD_LIGHT_GREEN] = "green",
  81         [IIO_MOD_LIGHT_BLUE] = "blue",
  82 };
  83
  84 /* relies on pairs of these shared then separate */
  85 static const char * const iio_chan_info_postfix[] = {
  86         [IIO_CHAN_INFO_RAW] = "raw",
  87         [IIO_CHAN_INFO_PROCESSED] = "input",
  88         [IIO_CHAN_INFO_SCALE] = "scale",
  89         [IIO_CHAN_INFO_OFFSET] = "offset",
  90         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
  91         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
  92         [IIO_CHAN_INFO_PEAK] = "peak_raw",
  93         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
  94         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
  95         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
  96         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
  97         = "filter_low_pass_3db_frequency",
  98         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
  99         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 100         [IIO_CHAN_INFO_PHASE] = "phase",
 101         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 102 };
 103
 104 const struct iio_chan_spec
 105 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 106 {
 107         int i;
 108
 109         for (i = 0; i < indio_dev->num_channels; i++)
 110                 if (indio_dev->channels[i].scan_index == si)
 111                         return &indio_dev->channels[i];
 112         return NULL;
 113 }
 114
 115 /* This turns up an awful lot */
 116 ssize_t iio_read_const_attr(struct device *dev,
 117                             struct device_attribute *attr,
 118                             char *buf)
 119 {
 120         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 121 }
 122 EXPORT_SYMBOL(iio_read_const_attr);
 123
 124 static int __init iio_init(void)
 125 {
 126         int ret;
 127
 128         /* Register sysfs bus */
 129         ret  = bus_register(&iio_bus_type);
 130         if (ret < 0) {
 131                 printk(KERN_ERR
 132                        "%s could not register bus type\n",
 133                         __FILE__);
 134                 goto error_nothing;
 135         }
 136
 137         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 138         if (ret < 0) {
 139                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 140                        __FILE__);
 141                 goto error_unregister_bus_type;
 142         }
 143
 144         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 145
 146         return 0;
 147
 148 error_unregister_bus_type:
 149         bus_unregister(&iio_bus_type);
 150 error_nothing:
 151         return ret;
 152 }
 153
 154 static void __exit iio_exit(void)
 155 {
 156         if (iio_devt)
 157                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 158         bus_unregister(&iio_bus_type);
 159         debugfs_remove(iio_debugfs_dentry);
 160 }
 161
 162 #if defined(CONFIG_DEBUG_FS)
 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 = simple_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 (!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 (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_to_iio_dev(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, ext_info->private, 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_to_iio_dev(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, ext_info->private,
 296                                this_attr->c, buf, len);
 297 }
 298
 299 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 300         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 301 {
 302         const struct iio_enum *e = (const struct iio_enum *)priv;
 303         unsigned int i;
 304         size_t len = 0;
 305
 306         if (!e->num_items)
 307                 return 0;
 308
 309         for (i = 0; i < e->num_items; ++i)
 310                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 311
 312         /* replace last space with a newline */
 313         buf[len - 1] = '\n';
 314
 315         return len;
 316 }
 317 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 318
 319 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 320         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 321 {
 322         const struct iio_enum *e = (const struct iio_enum *)priv;
 323         int i;
 324
 325         if (!e->get)
 326                 return -EINVAL;
 327
 328         i = e->get(indio_dev, chan);
 329         if (i < 0)
 330                 return i;
 331         else if (i >= e->num_items)
 332                 return -EINVAL;
 333
 334         return sprintf(buf, "%s\n", e->items[i]);
 335 }
 336 EXPORT_SYMBOL_GPL(iio_enum_read);
 337
 338 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 339         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 340         size_t len)
 341 {
 342         const struct iio_enum *e = (const struct iio_enum *)priv;
 343         unsigned int i;
 344         int ret;
 345
 346         if (!e->set)
 347                 return -EINVAL;
 348
 349         for (i = 0; i < e->num_items; i++) {
 350                 if (sysfs_streq(buf, e->items[i]))
 351                         break;
 352         }
 353
 354         if (i == e->num_items)
 355                 return -EINVAL;
 356
 357         ret = e->set(indio_dev, chan, i);
 358         return ret ? ret : len;
 359 }
 360 EXPORT_SYMBOL_GPL(iio_enum_write);
 361
 362 static ssize_t iio_read_channel_info(struct device *dev,
 363                                      struct device_attribute *attr,
 364                                      char *buf)
 365 {
 366         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 367         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 368         int val, val2;
 369         bool scale_db = false;
 370         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 371                                             &val, &val2, this_attr->address);
 372
 373         if (ret < 0)
 374                 return ret;
 375
 376         switch (ret) {
 377         case IIO_VAL_INT:
 378                 return sprintf(buf, "%d\n", val);
 379         case IIO_VAL_INT_PLUS_MICRO_DB:
 380                 scale_db = true;
 381         case IIO_VAL_INT_PLUS_MICRO:
 382                 if (val2 < 0)
 383                         return sprintf(buf, "-%d.%06u%s\n", val, -val2,
 384                                 scale_db ? " dB" : "");
 385                 else
 386                         return sprintf(buf, "%d.%06u%s\n", val, val2,
 387                                 scale_db ? " dB" : "");
 388         case IIO_VAL_INT_PLUS_NANO:
 389                 if (val2 < 0)
 390                         return sprintf(buf, "-%d.%09u\n", val, -val2);
 391                 else
 392                         return sprintf(buf, "%d.%09u\n", val, val2);
 393         default:
 394                 return 0;
 395         }
 396 }
 397
 398 static ssize_t iio_write_channel_info(struct device *dev,
 399                                       struct device_attribute *attr,
 400                                       const char *buf,
 401                                       size_t len)
 402 {
 403         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 404         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 405         int ret, integer = 0, fract = 0, fract_mult = 100000;
 406         bool integer_part = true, negative = false;
 407
 408         /* Assumes decimal - precision based on number of digits */
 409         if (!indio_dev->info->write_raw)
 410                 return -EINVAL;
 411
 412         if (indio_dev->info->write_raw_get_fmt)
 413                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 414                         this_attr->c, this_attr->address)) {
 415                 case IIO_VAL_INT_PLUS_MICRO:
 416                         fract_mult = 100000;
 417                         break;
 418                 case IIO_VAL_INT_PLUS_NANO:
 419                         fract_mult = 100000000;
 420                         break;
 421                 default:
 422                         return -EINVAL;
 423                 }
 424
 425         if (buf[0] == '-') {
 426                 negative = true;
 427                 buf++;
 428         }
 429
 430         while (*buf) {
 431                 if ('0' <= *buf && *buf <= '9') {
 432                         if (integer_part)
 433                                 integer = integer*10 + *buf - '0';
 434                         else {
 435                                 fract += fract_mult*(*buf - '0');
 436                                 if (fract_mult == 1)
 437                                         break;
 438                                 fract_mult /= 10;
 439                         }
 440                 } else if (*buf == '\n') {
 441                         if (*(buf + 1) == '\0')
 442                                 break;
 443                         else
 444                                 return -EINVAL;
 445                 } else if (*buf == '.') {
 446                         integer_part = false;
 447                 } else {
 448                         return -EINVAL;
 449                 }
 450                 buf++;
 451         }
 452         if (negative) {
 453                 if (integer)
 454                         integer = -integer;
 455                 else
 456                         fract = -fract;
 457         }
 458
 459         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 460                                          integer, fract, this_attr->address);
 461         if (ret)
 462                 return ret;
 463
 464         return len;
 465 }
 466
 467 static
 468 int __iio_device_attr_init(struct device_attribute *dev_attr,
 469                            const char *postfix,
 470                            struct iio_chan_spec const *chan,
 471                            ssize_t (*readfunc)(struct device *dev,
 472                                                struct device_attribute *attr,
 473                                                char *buf),
 474                            ssize_t (*writefunc)(struct device *dev,
 475                                                 struct device_attribute *attr,
 476                                                 const char *buf,
 477                                                 size_t len),
 478                            bool generic)
 479 {
 480         int ret;
 481         char *name_format, *full_postfix;
 482         sysfs_attr_init(&dev_attr->attr);
 483
 484         /* Build up postfix of <extend_name>_<modifier>_postfix */
 485         if (chan->modified && !generic) {
 486                 if (chan->extend_name)
 487                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 488                                                  iio_modifier_names[chan
 489                                                                     ->channel2],
 490                                                  chan->extend_name,
 491                                                  postfix);
 492                 else
 493                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 494                                                  iio_modifier_names[chan
 495                                                                     ->channel2],
 496                                                  postfix);
 497         } else {
 498                 if (chan->extend_name == NULL)
 499                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 500                 else
 501                         full_postfix = kasprintf(GFP_KERNEL,
 502                                                  "%s_%s",
 503                                                  chan->extend_name,
 504                                                  postfix);
 505         }
 506         if (full_postfix == NULL) {
 507                 ret = -ENOMEM;
 508                 goto error_ret;
 509         }
 510
 511         if (chan->differential) { /* Differential can not have modifier */
 512                 if (generic)
 513                         name_format
 514                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 515                                             iio_direction[chan->output],
 516                                             iio_chan_type_name_spec[chan->type],
 517                                             iio_chan_type_name_spec[chan->type],
 518                                             full_postfix);
 519                 else if (chan->indexed)
 520                         name_format
 521                                 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
 522                                             iio_direction[chan->output],
 523                                             iio_chan_type_name_spec[chan->type],
 524                                             chan->channel,
 525                                             iio_chan_type_name_spec[chan->type],
 526                                             chan->channel2,
 527                                             full_postfix);
 528                 else {
 529                         WARN_ON("Differential channels must be indexed\n");
 530                         ret = -EINVAL;
 531                         goto error_free_full_postfix;
 532                 }
 533         } else { /* Single ended */
 534                 if (generic)
 535                         name_format
 536                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 537                                             iio_direction[chan->output],
 538                                             iio_chan_type_name_spec[chan->type],
 539                                             full_postfix);
 540                 else if (chan->indexed)
 541                         name_format
 542                                 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 543                                             iio_direction[chan->output],
 544                                             iio_chan_type_name_spec[chan->type],
 545                                             chan->channel,
 546                                             full_postfix);
 547                 else
 548                         name_format
 549                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 550                                             iio_direction[chan->output],
 551                                             iio_chan_type_name_spec[chan->type],
 552                                             full_postfix);
 553         }
 554         if (name_format == NULL) {
 555                 ret = -ENOMEM;
 556                 goto error_free_full_postfix;
 557         }
 558         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 559                                         name_format,
 560                                         chan->channel,
 561                                         chan->channel2);
 562         if (dev_attr->attr.name == NULL) {
 563                 ret = -ENOMEM;
 564                 goto error_free_name_format;
 565         }
 566
 567         if (readfunc) {
 568                 dev_attr->attr.mode |= S_IRUGO;
 569                 dev_attr->show = readfunc;
 570         }
 571
 572         if (writefunc) {
 573                 dev_attr->attr.mode |= S_IWUSR;
 574                 dev_attr->store = writefunc;
 575         }
 576         kfree(name_format);
 577         kfree(full_postfix);
 578
 579         return 0;
 580
 581 error_free_name_format:
 582         kfree(name_format);
 583 error_free_full_postfix:
 584         kfree(full_postfix);
 585 error_ret:
 586         return ret;
 587 }
 588
 589 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 590 {
 591         kfree(dev_attr->attr.name);
 592 }
 593
 594 int __iio_add_chan_devattr(const char *postfix,
 595                            struct iio_chan_spec const *chan,
 596                            ssize_t (*readfunc)(struct device *dev,
 597                                                struct device_attribute *attr,
 598                                                char *buf),
 599                            ssize_t (*writefunc)(struct device *dev,
 600                                                 struct device_attribute *attr,
 601                                                 const char *buf,
 602                                                 size_t len),
 603                            u64 mask,
 604                            bool generic,
 605                            struct device *dev,
 606                            struct list_head *attr_list)
 607 {
 608         int ret;
 609         struct iio_dev_attr *iio_attr, *t;
 610
 611         iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
 612         if (iio_attr == NULL) {
 613                 ret = -ENOMEM;
 614                 goto error_ret;
 615         }
 616         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 617                                      postfix, chan,
 618                                      readfunc, writefunc, generic);
 619         if (ret)
 620                 goto error_iio_dev_attr_free;
 621         iio_attr->c = chan;
 622         iio_attr->address = mask;
 623         list_for_each_entry(t, attr_list, l)
 624                 if (strcmp(t->dev_attr.attr.name,
 625                            iio_attr->dev_attr.attr.name) == 0) {
 626                         if (!generic)
 627                                 dev_err(dev, "tried to double register : %s\n",
 628                                         t->dev_attr.attr.name);
 629                         ret = -EBUSY;
 630                         goto error_device_attr_deinit;
 631                 }
 632         list_add(&iio_attr->l, attr_list);
 633
 634         return 0;
 635
 636 error_device_attr_deinit:
 637         __iio_device_attr_deinit(&iio_attr->dev_attr);
 638 error_iio_dev_attr_free:
 639         kfree(iio_attr);
 640 error_ret:
 641         return ret;
 642 }
 643
 644 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 645                                         struct iio_chan_spec const *chan)
 646 {
 647         int ret, attrcount = 0;
 648         int i;
 649         const struct iio_chan_spec_ext_info *ext_info;
 650
 651         if (chan->channel < 0)
 652                 return 0;
 653         for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
 654                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
 655                                              chan,
 656                                              &iio_read_channel_info,
 657                                              &iio_write_channel_info,
 658                                              i/2,
 659                                              !(i%2),
 660                                              &indio_dev->dev,
 661                                              &indio_dev->channel_attr_list);
 662                 if (ret == -EBUSY && (i%2 == 0)) {
 663                         ret = 0;
 664                         continue;
 665                 }
 666                 if (ret < 0)
 667                         goto error_ret;
 668                 attrcount++;
 669         }
 670
 671         if (chan->ext_info) {
 672                 unsigned int i = 0;
 673                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 674                         ret = __iio_add_chan_devattr(ext_info->name,
 675                                         chan,
 676                                         ext_info->read ?
 677                                             &iio_read_channel_ext_info : NULL,
 678                                         ext_info->write ?
 679                                             &iio_write_channel_ext_info : NULL,
 680                                         i,
 681                                         ext_info->shared,
 682                                         &indio_dev->dev,
 683                                         &indio_dev->channel_attr_list);
 684                         i++;
 685                         if (ret == -EBUSY && ext_info->shared)
 686                                 continue;
 687
 688                         if (ret)
 689                                 goto error_ret;
 690
 691                         attrcount++;
 692                 }
 693         }
 694
 695         ret = attrcount;
 696 error_ret:
 697         return ret;
 698 }
 699
 700 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
 701                                                  struct iio_dev_attr *p)
 702 {
 703         kfree(p->dev_attr.attr.name);
 704         kfree(p);
 705 }
 706
 707 static ssize_t iio_show_dev_name(struct device *dev,
 708                                  struct device_attribute *attr,
 709                                  char *buf)
 710 {
 711         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 712         return sprintf(buf, "%s\n", indio_dev->name);
 713 }
 714
 715 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 716
 717 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 718 {
 719         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 720         struct iio_dev_attr *p, *n;
 721         struct attribute **attr;
 722
 723         /* First count elements in any existing group */
 724         if (indio_dev->info->attrs) {
 725                 attr = indio_dev->info->attrs->attrs;
 726                 while (*attr++ != NULL)
 727                         attrcount_orig++;
 728         }
 729         attrcount = attrcount_orig;
 730         /*
 731          * New channel registration method - relies on the fact a group does
 732          * not need to be initialized if it is name is NULL.
 733          */
 734         if (indio_dev->channels)
 735                 for (i = 0; i < indio_dev->num_channels; i++) {
 736                         ret = iio_device_add_channel_sysfs(indio_dev,
 737                                                            &indio_dev
 738                                                            ->channels[i]);
 739                         if (ret < 0)
 740                                 goto error_clear_attrs;
 741                         attrcount += ret;
 742                 }
 743
 744         if (indio_dev->name)
 745                 attrcount++;
 746
 747         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 748                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 749                                                    GFP_KERNEL);
 750         if (indio_dev->chan_attr_group.attrs == NULL) {
 751                 ret = -ENOMEM;
 752                 goto error_clear_attrs;
 753         }
 754         /* Copy across original attributes */
 755         if (indio_dev->info->attrs)
 756                 memcpy(indio_dev->chan_attr_group.attrs,
 757                        indio_dev->info->attrs->attrs,
 758                        sizeof(indio_dev->chan_attr_group.attrs[0])
 759                        *attrcount_orig);
 760         attrn = attrcount_orig;
 761         /* Add all elements from the list. */
 762         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 763                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 764         if (indio_dev->name)
 765                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 766
 767         indio_dev->groups[indio_dev->groupcounter++] =
 768                 &indio_dev->chan_attr_group;
 769
 770         return 0;
 771
 772 error_clear_attrs:
 773         list_for_each_entry_safe(p, n,
 774                                  &indio_dev->channel_attr_list, l) {
 775                 list_del(&p->l);
 776                 iio_device_remove_and_free_read_attr(indio_dev, p);
 777         }
 778
 779         return ret;
 780 }
 781
 782 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 783 {
 784
 785         struct iio_dev_attr *p, *n;
 786
 787         list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
 788                 list_del(&p->l);
 789                 iio_device_remove_and_free_read_attr(indio_dev, p);
 790         }
 791         kfree(indio_dev->chan_attr_group.attrs);
 792 }
 793
 794 static void iio_dev_release(struct device *device)
 795 {
 796         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 797         if (indio_dev->chrdev.dev)
 798                 cdev_del(&indio_dev->chrdev);
 799         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 800                 iio_device_unregister_trigger_consumer(indio_dev);
 801         iio_device_unregister_eventset(indio_dev);
 802         iio_device_unregister_sysfs(indio_dev);
 803         iio_device_unregister_debugfs(indio_dev);
 804
 805         ida_simple_remove(&iio_ida, indio_dev->id);
 806         kfree(indio_dev);
 807 }
 808
 809 static struct device_type iio_dev_type = {
 810         .name = "iio_device",
 811         .release = iio_dev_release,
 812 };
 813
 814 struct iio_dev *iio_device_alloc(int sizeof_priv)
 815 {
 816         struct iio_dev *dev;
 817         size_t alloc_size;
 818
 819         alloc_size = sizeof(struct iio_dev);
 820         if (sizeof_priv) {
 821                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 822                 alloc_size += sizeof_priv;
 823         }
 824         /* ensure 32-byte alignment of whole construct ? */
 825         alloc_size += IIO_ALIGN - 1;
 826
 827         dev = kzalloc(alloc_size, GFP_KERNEL);
 828
 829         if (dev) {
 830                 dev->dev.groups = dev->groups;
 831                 dev->dev.type = &iio_dev_type;
 832                 dev->dev.bus = &iio_bus_type;
 833                 device_initialize(&dev->dev);
 834                 dev_set_drvdata(&dev->dev, (void *)dev);
 835                 mutex_init(&dev->mlock);
 836                 mutex_init(&dev->info_exist_lock);
 837                 INIT_LIST_HEAD(&dev->channel_attr_list);
 838
 839                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 840                 if (dev->id < 0) {
 841                         /* cannot use a dev_err as the name isn't available */
 842                         printk(KERN_ERR "Failed to get id\n");
 843                         kfree(dev);
 844                         return NULL;
 845                 }
 846                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 847         }
 848
 849         return dev;
 850 }
 851 EXPORT_SYMBOL(iio_device_alloc);
 852
 853 void iio_device_free(struct iio_dev *dev)
 854 {
 855         if (dev)
 856                 put_device(&dev->dev);
 857 }
 858 EXPORT_SYMBOL(iio_device_free);
 859
 860 /**
 861  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
 862  **/
 863 static int iio_chrdev_open(struct inode *inode, struct file *filp)
 864 {
 865         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 866                                                 struct iio_dev, chrdev);
 867
 868         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 869                 return -EBUSY;
 870
 871         filp->private_data = indio_dev;
 872
 873         return 0;
 874 }
 875
 876 /**
 877  * iio_chrdev_release() - chrdev file close buffer access and ioctls
 878  **/
 879 static int iio_chrdev_release(struct inode *inode, struct file *filp)
 880 {
 881         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 882                                                 struct iio_dev, chrdev);
 883         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
 884         return 0;
 885 }
 886
 887 /* Somewhat of a cross file organization violation - ioctls here are actually
 888  * event related */
 889 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 890 {
 891         struct iio_dev *indio_dev = filp->private_data;
 892         int __user *ip = (int __user *)arg;
 893         int fd;
 894
 895         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 896                 fd = iio_event_getfd(indio_dev);
 897                 if (copy_to_user(ip, &fd, sizeof(fd)))
 898                         return -EFAULT;
 899                 return 0;
 900         }
 901         return -EINVAL;
 902 }
 903
 904 static const struct file_operations iio_buffer_fileops = {
 905         .read = iio_buffer_read_first_n_outer_addr,
 906         .release = iio_chrdev_release,
 907         .open = iio_chrdev_open,
 908         .poll = iio_buffer_poll_addr,
 909         .owner = THIS_MODULE,
 910         .llseek = noop_llseek,
 911         .unlocked_ioctl = iio_ioctl,
 912         .compat_ioctl = iio_ioctl,
 913 };
 914
 915 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
 916
 917 int iio_device_register(struct iio_dev *indio_dev)
 918 {
 919         int ret;
 920
 921         /* configure elements for the chrdev */
 922         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
 923
 924         ret = iio_device_register_debugfs(indio_dev);
 925         if (ret) {
 926                 dev_err(indio_dev->dev.parent,
 927                         "Failed to register debugfs interfaces\n");
 928                 goto error_ret;
 929         }
 930         ret = iio_device_register_sysfs(indio_dev);
 931         if (ret) {
 932                 dev_err(indio_dev->dev.parent,
 933                         "Failed to register sysfs interfaces\n");
 934                 goto error_unreg_debugfs;
 935         }
 936         ret = iio_device_register_eventset(indio_dev);
 937         if (ret) {
 938                 dev_err(indio_dev->dev.parent,
 939                         "Failed to register event set\n");
 940                 goto error_free_sysfs;
 941         }
 942         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 943                 iio_device_register_trigger_consumer(indio_dev);
 944
 945         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
 946                 indio_dev->setup_ops == NULL)
 947                 indio_dev->setup_ops = &noop_ring_setup_ops;
 948
 949         ret = device_add(&indio_dev->dev);
 950         if (ret < 0)
 951                 goto error_unreg_eventset;
 952         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 953         indio_dev->chrdev.owner = indio_dev->info->driver_module;
 954         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 955         if (ret < 0)
 956                 goto error_del_device;
 957         return 0;
 958
 959 error_del_device:
 960         device_del(&indio_dev->dev);
 961 error_unreg_eventset:
 962         iio_device_unregister_eventset(indio_dev);
 963 error_free_sysfs:
 964         iio_device_unregister_sysfs(indio_dev);
 965 error_unreg_debugfs:
 966         iio_device_unregister_debugfs(indio_dev);
 967 error_ret:
 968         return ret;
 969 }
 970 EXPORT_SYMBOL(iio_device_register);
 971
 972 void iio_device_unregister(struct iio_dev *indio_dev)
 973 {
 974         mutex_lock(&indio_dev->info_exist_lock);
 975         indio_dev->info = NULL;
 976         mutex_unlock(&indio_dev->info_exist_lock);
 977         device_del(&indio_dev->dev);
 978 }
 979 EXPORT_SYMBOL(iio_device_unregister);
 980 subsys_initcall(iio_init);
 981 module_exit(iio_exit);
 982
 983 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 984 MODULE_DESCRIPTION("Industrial I/O core");
 985 MODULE_LICENSE("GPL");