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         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 103 };
 104
 105 const struct iio_chan_spec
 106 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 107 {
 108         int i;
 109
 110         for (i = 0; i < indio_dev->num_channels; i++)
 111                 if (indio_dev->channels[i].scan_index == si)
 112                         return &indio_dev->channels[i];
 113         return NULL;
 114 }
 115
 116 /* This turns up an awful lot */
 117 ssize_t iio_read_const_attr(struct device *dev,
 118                             struct device_attribute *attr,
 119                             char *buf)
 120 {
 121         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 122 }
 123 EXPORT_SYMBOL(iio_read_const_attr);
 124
 125 static int __init iio_init(void)
 126 {
 127         int ret;
 128
 129         /* Register sysfs bus */
 130         ret  = bus_register(&iio_bus_type);
 131         if (ret < 0) {
 132                 printk(KERN_ERR
 133                        "%s could not register bus type\n",
 134                         __FILE__);
 135                 goto error_nothing;
 136         }
 137
 138         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 139         if (ret < 0) {
 140                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 141                        __FILE__);
 142                 goto error_unregister_bus_type;
 143         }
 144
 145         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 146
 147         return 0;
 148
 149 error_unregister_bus_type:
 150         bus_unregister(&iio_bus_type);
 151 error_nothing:
 152         return ret;
 153 }
 154
 155 static void __exit iio_exit(void)
 156 {
 157         if (iio_devt)
 158                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 159         bus_unregister(&iio_bus_type);
 160         debugfs_remove(iio_debugfs_dentry);
 161 }
 162
 163 #if defined(CONFIG_DEBUG_FS)
 164 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 165                               size_t count, loff_t *ppos)
 166 {
 167         struct iio_dev *indio_dev = file->private_data;
 168         char buf[20];
 169         unsigned val = 0;
 170         ssize_t len;
 171         int ret;
 172
 173         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 174                                                   indio_dev->cached_reg_addr,
 175                                                   0, &val);
 176         if (ret)
 177                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 178
 179         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 180
 181         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 182 }
 183
 184 static ssize_t iio_debugfs_write_reg(struct file *file,
 185                      const char __user *userbuf, size_t count, loff_t *ppos)
 186 {
 187         struct iio_dev *indio_dev = file->private_data;
 188         unsigned reg, val;
 189         char buf[80];
 190         int ret;
 191
 192         count = min_t(size_t, count, (sizeof(buf)-1));
 193         if (copy_from_user(buf, userbuf, count))
 194                 return -EFAULT;
 195
 196         buf[count] = 0;
 197
 198         ret = sscanf(buf, "%i %i", &reg, &val);
 199
 200         switch (ret) {
 201         case 1:
 202                 indio_dev->cached_reg_addr = reg;
 203                 break;
 204         case 2:
 205                 indio_dev->cached_reg_addr = reg;
 206                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 207                                                           val, NULL);
 208                 if (ret) {
 209                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 210                                 __func__);
 211                         return ret;
 212                 }
 213                 break;
 214         default:
 215                 return -EINVAL;
 216         }
 217
 218         return count;
 219 }
 220
 221 static const struct file_operations iio_debugfs_reg_fops = {
 222         .open = simple_open,
 223         .read = iio_debugfs_read_reg,
 224         .write = iio_debugfs_write_reg,
 225 };
 226
 227 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 228 {
 229         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 230 }
 231
 232 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 233 {
 234         struct dentry *d;
 235
 236         if (indio_dev->info->debugfs_reg_access == NULL)
 237                 return 0;
 238
 239         if (!iio_debugfs_dentry)
 240                 return 0;
 241
 242         indio_dev->debugfs_dentry =
 243                 debugfs_create_dir(dev_name(&indio_dev->dev),
 244                                    iio_debugfs_dentry);
 245         if (indio_dev->debugfs_dentry == NULL) {
 246                 dev_warn(indio_dev->dev.parent,
 247                          "Failed to create debugfs directory\n");
 248                 return -EFAULT;
 249         }
 250
 251         d = debugfs_create_file("direct_reg_access", 0644,
 252                                 indio_dev->debugfs_dentry,
 253                                 indio_dev, &iio_debugfs_reg_fops);
 254         if (!d) {
 255                 iio_device_unregister_debugfs(indio_dev);
 256                 return -ENOMEM;
 257         }
 258
 259         return 0;
 260 }
 261 #else
 262 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 263 {
 264         return 0;
 265 }
 266
 267 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 268 {
 269 }
 270 #endif /* CONFIG_DEBUG_FS */
 271
 272 static ssize_t iio_read_channel_ext_info(struct device *dev,
 273                                      struct device_attribute *attr,
 274                                      char *buf)
 275 {
 276         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 277         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 278         const struct iio_chan_spec_ext_info *ext_info;
 279
 280         ext_info = &this_attr->c->ext_info[this_attr->address];
 281
 282         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 283 }
 284
 285 static ssize_t iio_write_channel_ext_info(struct device *dev,
 286                                      struct device_attribute *attr,
 287                                      const char *buf,
 288                                          size_t len)
 289 {
 290         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 291         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 292         const struct iio_chan_spec_ext_info *ext_info;
 293
 294         ext_info = &this_attr->c->ext_info[this_attr->address];
 295
 296         return ext_info->write(indio_dev, ext_info->private,
 297                                this_attr->c, buf, len);
 298 }
 299
 300 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 301         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 302 {
 303         const struct iio_enum *e = (const struct iio_enum *)priv;
 304         unsigned int i;
 305         size_t len = 0;
 306
 307         if (!e->num_items)
 308                 return 0;
 309
 310         for (i = 0; i < e->num_items; ++i)
 311                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 312
 313         /* replace last space with a newline */
 314         buf[len - 1] = '\n';
 315
 316         return len;
 317 }
 318 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 319
 320 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 321         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 322 {
 323         const struct iio_enum *e = (const struct iio_enum *)priv;
 324         int i;
 325
 326         if (!e->get)
 327                 return -EINVAL;
 328
 329         i = e->get(indio_dev, chan);
 330         if (i < 0)
 331                 return i;
 332         else if (i >= e->num_items)
 333                 return -EINVAL;
 334
 335         return sprintf(buf, "%s\n", e->items[i]);
 336 }
 337 EXPORT_SYMBOL_GPL(iio_enum_read);
 338
 339 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 340         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 341         size_t len)
 342 {
 343         const struct iio_enum *e = (const struct iio_enum *)priv;
 344         unsigned int i;
 345         int ret;
 346
 347         if (!e->set)
 348                 return -EINVAL;
 349
 350         for (i = 0; i < e->num_items; i++) {
 351                 if (sysfs_streq(buf, e->items[i]))
 352                         break;
 353         }
 354
 355         if (i == e->num_items)
 356                 return -EINVAL;
 357
 358         ret = e->set(indio_dev, chan, i);
 359         return ret ? ret : len;
 360 }
 361 EXPORT_SYMBOL_GPL(iio_enum_write);
 362
 363 static ssize_t iio_read_channel_info(struct device *dev,
 364                                      struct device_attribute *attr,
 365                                      char *buf)
 366 {
 367         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 368         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 369         int val, val2;
 370         bool scale_db = false;
 371         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 372                                             &val, &val2, this_attr->address);
 373
 374         if (ret < 0)
 375                 return ret;
 376
 377         switch (ret) {
 378         case IIO_VAL_INT:
 379                 return sprintf(buf, "%d\n", val);
 380         case IIO_VAL_INT_PLUS_MICRO_DB:
 381                 scale_db = true;
 382         case IIO_VAL_INT_PLUS_MICRO:
 383                 if (val2 < 0)
 384                         return sprintf(buf, "-%d.%06u%s\n", val, -val2,
 385                                 scale_db ? " dB" : "");
 386                 else
 387                         return sprintf(buf, "%d.%06u%s\n", val, val2,
 388                                 scale_db ? " dB" : "");
 389         case IIO_VAL_INT_PLUS_NANO:
 390                 if (val2 < 0)
 391                         return sprintf(buf, "-%d.%09u\n", val, -val2);
 392                 else
 393                         return sprintf(buf, "%d.%09u\n", val, val2);
 394         default:
 395                 return 0;
 396         }
 397 }
 398
 399 static ssize_t iio_write_channel_info(struct device *dev,
 400                                       struct device_attribute *attr,
 401                                       const char *buf,
 402                                       size_t len)
 403 {
 404         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 405         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 406         int ret, integer = 0, fract = 0, fract_mult = 100000;
 407         bool integer_part = true, negative = false;
 408
 409         /* Assumes decimal - precision based on number of digits */
 410         if (!indio_dev->info->write_raw)
 411                 return -EINVAL;
 412
 413         if (indio_dev->info->write_raw_get_fmt)
 414                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 415                         this_attr->c, this_attr->address)) {
 416                 case IIO_VAL_INT_PLUS_MICRO:
 417                         fract_mult = 100000;
 418                         break;
 419                 case IIO_VAL_INT_PLUS_NANO:
 420                         fract_mult = 100000000;
 421                         break;
 422                 default:
 423                         return -EINVAL;
 424                 }
 425
 426         if (buf[0] == '-') {
 427                 negative = true;
 428                 buf++;
 429         }
 430
 431         while (*buf) {
 432                 if ('0' <= *buf && *buf <= '9') {
 433                         if (integer_part)
 434                                 integer = integer*10 + *buf - '0';
 435                         else {
 436                                 fract += fract_mult*(*buf - '0');
 437                                 if (fract_mult == 1)
 438                                         break;
 439                                 fract_mult /= 10;
 440                         }
 441                 } else if (*buf == '\n') {
 442                         if (*(buf + 1) == '\0')
 443                                 break;
 444                         else
 445                                 return -EINVAL;
 446                 } else if (*buf == '.') {
 447                         integer_part = false;
 448                 } else {
 449                         return -EINVAL;
 450                 }
 451                 buf++;
 452         }
 453         if (negative) {
 454                 if (integer)
 455                         integer = -integer;
 456                 else
 457                         fract = -fract;
 458         }
 459
 460         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 461                                          integer, fract, this_attr->address);
 462         if (ret)
 463                 return ret;
 464
 465         return len;
 466 }
 467
 468 static
 469 int __iio_device_attr_init(struct device_attribute *dev_attr,
 470                            const char *postfix,
 471                            struct iio_chan_spec const *chan,
 472                            ssize_t (*readfunc)(struct device *dev,
 473                                                struct device_attribute *attr,
 474                                                char *buf),
 475                            ssize_t (*writefunc)(struct device *dev,
 476                                                 struct device_attribute *attr,
 477                                                 const char *buf,
 478                                                 size_t len),
 479                            bool generic)
 480 {
 481         int ret;
 482         char *name_format, *full_postfix;
 483         sysfs_attr_init(&dev_attr->attr);
 484
 485         /* Build up postfix of <extend_name>_<modifier>_postfix */
 486         if (chan->modified && !generic) {
 487                 if (chan->extend_name)
 488                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 489                                                  iio_modifier_names[chan
 490                                                                     ->channel2],
 491                                                  chan->extend_name,
 492                                                  postfix);
 493                 else
 494                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 495                                                  iio_modifier_names[chan
 496                                                                     ->channel2],
 497                                                  postfix);
 498         } else {
 499                 if (chan->extend_name == NULL)
 500                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 501                 else
 502                         full_postfix = kasprintf(GFP_KERNEL,
 503                                                  "%s_%s",
 504                                                  chan->extend_name,
 505                                                  postfix);
 506         }
 507         if (full_postfix == NULL) {
 508                 ret = -ENOMEM;
 509                 goto error_ret;
 510         }
 511
 512         if (chan->differential) { /* Differential can not have modifier */
 513                 if (generic)
 514                         name_format
 515                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 516                                             iio_direction[chan->output],
 517                                             iio_chan_type_name_spec[chan->type],
 518                                             iio_chan_type_name_spec[chan->type],
 519                                             full_postfix);
 520                 else if (chan->indexed)
 521                         name_format
 522                                 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
 523                                             iio_direction[chan->output],
 524                                             iio_chan_type_name_spec[chan->type],
 525                                             chan->channel,
 526                                             iio_chan_type_name_spec[chan->type],
 527                                             chan->channel2,
 528                                             full_postfix);
 529                 else {
 530                         WARN_ON("Differential channels must be indexed\n");
 531                         ret = -EINVAL;
 532                         goto error_free_full_postfix;
 533                 }
 534         } else { /* Single ended */
 535                 if (generic)
 536                         name_format
 537                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 538                                             iio_direction[chan->output],
 539                                             iio_chan_type_name_spec[chan->type],
 540                                             full_postfix);
 541                 else if (chan->indexed)
 542                         name_format
 543                                 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 544                                             iio_direction[chan->output],
 545                                             iio_chan_type_name_spec[chan->type],
 546                                             chan->channel,
 547                                             full_postfix);
 548                 else
 549                         name_format
 550                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 551                                             iio_direction[chan->output],
 552                                             iio_chan_type_name_spec[chan->type],
 553                                             full_postfix);
 554         }
 555         if (name_format == NULL) {
 556                 ret = -ENOMEM;
 557                 goto error_free_full_postfix;
 558         }
 559         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 560                                         name_format,
 561                                         chan->channel,
 562                                         chan->channel2);
 563         if (dev_attr->attr.name == NULL) {
 564                 ret = -ENOMEM;
 565                 goto error_free_name_format;
 566         }
 567
 568         if (readfunc) {
 569                 dev_attr->attr.mode |= S_IRUGO;
 570                 dev_attr->show = readfunc;
 571         }
 572
 573         if (writefunc) {
 574                 dev_attr->attr.mode |= S_IWUSR;
 575                 dev_attr->store = writefunc;
 576         }
 577         kfree(name_format);
 578         kfree(full_postfix);
 579
 580         return 0;
 581
 582 error_free_name_format:
 583         kfree(name_format);
 584 error_free_full_postfix:
 585         kfree(full_postfix);
 586 error_ret:
 587         return ret;
 588 }
 589
 590 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 591 {
 592         kfree(dev_attr->attr.name);
 593 }
 594
 595 int __iio_add_chan_devattr(const char *postfix,
 596                            struct iio_chan_spec const *chan,
 597                            ssize_t (*readfunc)(struct device *dev,
 598                                                struct device_attribute *attr,
 599                                                char *buf),
 600                            ssize_t (*writefunc)(struct device *dev,
 601                                                 struct device_attribute *attr,
 602                                                 const char *buf,
 603                                                 size_t len),
 604                            u64 mask,
 605                            bool generic,
 606                            struct device *dev,
 607                            struct list_head *attr_list)
 608 {
 609         int ret;
 610         struct iio_dev_attr *iio_attr, *t;
 611
 612         iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
 613         if (iio_attr == NULL) {
 614                 ret = -ENOMEM;
 615                 goto error_ret;
 616         }
 617         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 618                                      postfix, chan,
 619                                      readfunc, writefunc, generic);
 620         if (ret)
 621                 goto error_iio_dev_attr_free;
 622         iio_attr->c = chan;
 623         iio_attr->address = mask;
 624         list_for_each_entry(t, attr_list, l)
 625                 if (strcmp(t->dev_attr.attr.name,
 626                            iio_attr->dev_attr.attr.name) == 0) {
 627                         if (!generic)
 628                                 dev_err(dev, "tried to double register : %s\n",
 629                                         t->dev_attr.attr.name);
 630                         ret = -EBUSY;
 631                         goto error_device_attr_deinit;
 632                 }
 633         list_add(&iio_attr->l, attr_list);
 634
 635         return 0;
 636
 637 error_device_attr_deinit:
 638         __iio_device_attr_deinit(&iio_attr->dev_attr);
 639 error_iio_dev_attr_free:
 640         kfree(iio_attr);
 641 error_ret:
 642         return ret;
 643 }
 644
 645 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 646                                         struct iio_chan_spec const *chan)
 647 {
 648         int ret, attrcount = 0;
 649         int i;
 650         const struct iio_chan_spec_ext_info *ext_info;
 651
 652         if (chan->channel < 0)
 653                 return 0;
 654         for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
 655                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
 656                                              chan,
 657                                              &iio_read_channel_info,
 658                                              &iio_write_channel_info,
 659                                              i/2,
 660                                              !(i%2),
 661                                              &indio_dev->dev,
 662                                              &indio_dev->channel_attr_list);
 663                 if (ret == -EBUSY && (i%2 == 0)) {
 664                         ret = 0;
 665                         continue;
 666                 }
 667                 if (ret < 0)
 668                         goto error_ret;
 669                 attrcount++;
 670         }
 671
 672         if (chan->ext_info) {
 673                 unsigned int i = 0;
 674                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 675                         ret = __iio_add_chan_devattr(ext_info->name,
 676                                         chan,
 677                                         ext_info->read ?
 678                                             &iio_read_channel_ext_info : NULL,
 679                                         ext_info->write ?
 680                                             &iio_write_channel_ext_info : NULL,
 681                                         i,
 682                                         ext_info->shared,
 683                                         &indio_dev->dev,
 684                                         &indio_dev->channel_attr_list);
 685                         i++;
 686                         if (ret == -EBUSY && ext_info->shared)
 687                                 continue;
 688
 689                         if (ret)
 690                                 goto error_ret;
 691
 692                         attrcount++;
 693                 }
 694         }
 695
 696         ret = attrcount;
 697 error_ret:
 698         return ret;
 699 }
 700
 701 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
 702                                                  struct iio_dev_attr *p)
 703 {
 704         kfree(p->dev_attr.attr.name);
 705         kfree(p);
 706 }
 707
 708 static ssize_t iio_show_dev_name(struct device *dev,
 709                                  struct device_attribute *attr,
 710                                  char *buf)
 711 {
 712         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 713         return sprintf(buf, "%s\n", indio_dev->name);
 714 }
 715
 716 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 717
 718 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 719 {
 720         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 721         struct iio_dev_attr *p, *n;
 722         struct attribute **attr;
 723
 724         /* First count elements in any existing group */
 725         if (indio_dev->info->attrs) {
 726                 attr = indio_dev->info->attrs->attrs;
 727                 while (*attr++ != NULL)
 728                         attrcount_orig++;
 729         }
 730         attrcount = attrcount_orig;
 731         /*
 732          * New channel registration method - relies on the fact a group does
 733          * not need to be initialized if its name is NULL.
 734          */
 735         if (indio_dev->channels)
 736                 for (i = 0; i < indio_dev->num_channels; i++) {
 737                         ret = iio_device_add_channel_sysfs(indio_dev,
 738                                                            &indio_dev
 739                                                            ->channels[i]);
 740                         if (ret < 0)
 741                                 goto error_clear_attrs;
 742                         attrcount += ret;
 743                 }
 744
 745         if (indio_dev->name)
 746                 attrcount++;
 747
 748         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 749                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 750                                                    GFP_KERNEL);
 751         if (indio_dev->chan_attr_group.attrs == NULL) {
 752                 ret = -ENOMEM;
 753                 goto error_clear_attrs;
 754         }
 755         /* Copy across original attributes */
 756         if (indio_dev->info->attrs)
 757                 memcpy(indio_dev->chan_attr_group.attrs,
 758                        indio_dev->info->attrs->attrs,
 759                        sizeof(indio_dev->chan_attr_group.attrs[0])
 760                        *attrcount_orig);
 761         attrn = attrcount_orig;
 762         /* Add all elements from the list. */
 763         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 764                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 765         if (indio_dev->name)
 766                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 767
 768         indio_dev->groups[indio_dev->groupcounter++] =
 769                 &indio_dev->chan_attr_group;
 770
 771         return 0;
 772
 773 error_clear_attrs:
 774         list_for_each_entry_safe(p, n,
 775                                  &indio_dev->channel_attr_list, l) {
 776                 list_del(&p->l);
 777                 iio_device_remove_and_free_read_attr(indio_dev, p);
 778         }
 779
 780         return ret;
 781 }
 782
 783 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 784 {
 785
 786         struct iio_dev_attr *p, *n;
 787
 788         list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
 789                 list_del(&p->l);
 790                 iio_device_remove_and_free_read_attr(indio_dev, p);
 791         }
 792         kfree(indio_dev->chan_attr_group.attrs);
 793 }
 794
 795 static void iio_dev_release(struct device *device)
 796 {
 797         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 798         if (indio_dev->chrdev.dev)
 799                 cdev_del(&indio_dev->chrdev);
 800         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 801                 iio_device_unregister_trigger_consumer(indio_dev);
 802         iio_device_unregister_eventset(indio_dev);
 803         iio_device_unregister_sysfs(indio_dev);
 804         iio_device_unregister_debugfs(indio_dev);
 805
 806         ida_simple_remove(&iio_ida, indio_dev->id);
 807         kfree(indio_dev);
 808 }
 809
 810 static struct device_type iio_dev_type = {
 811         .name = "iio_device",
 812         .release = iio_dev_release,
 813 };
 814
 815 struct iio_dev *iio_device_alloc(int sizeof_priv)
 816 {
 817         struct iio_dev *dev;
 818         size_t alloc_size;
 819
 820         alloc_size = sizeof(struct iio_dev);
 821         if (sizeof_priv) {
 822                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 823                 alloc_size += sizeof_priv;
 824         }
 825         /* ensure 32-byte alignment of whole construct ? */
 826         alloc_size += IIO_ALIGN - 1;
 827
 828         dev = kzalloc(alloc_size, GFP_KERNEL);
 829
 830         if (dev) {
 831                 dev->dev.groups = dev->groups;
 832                 dev->dev.type = &iio_dev_type;
 833                 dev->dev.bus = &iio_bus_type;
 834                 device_initialize(&dev->dev);
 835                 dev_set_drvdata(&dev->dev, (void *)dev);
 836                 mutex_init(&dev->mlock);
 837                 mutex_init(&dev->info_exist_lock);
 838                 INIT_LIST_HEAD(&dev->channel_attr_list);
 839
 840                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 841                 if (dev->id < 0) {
 842                         /* cannot use a dev_err as the name isn't available */
 843                         printk(KERN_ERR "Failed to get id\n");
 844                         kfree(dev);
 845                         return NULL;
 846                 }
 847                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 848         }
 849
 850         return dev;
 851 }
 852 EXPORT_SYMBOL(iio_device_alloc);
 853
 854 void iio_device_free(struct iio_dev *dev)
 855 {
 856         if (dev)
 857                 put_device(&dev->dev);
 858 }
 859 EXPORT_SYMBOL(iio_device_free);
 860
 861 /**
 862  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
 863  **/
 864 static int iio_chrdev_open(struct inode *inode, struct file *filp)
 865 {
 866         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 867                                                 struct iio_dev, chrdev);
 868
 869         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 870                 return -EBUSY;
 871
 872         filp->private_data = indio_dev;
 873
 874         return 0;
 875 }
 876
 877 /**
 878  * iio_chrdev_release() - chrdev file close buffer access and ioctls
 879  **/
 880 static int iio_chrdev_release(struct inode *inode, struct file *filp)
 881 {
 882         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 883                                                 struct iio_dev, chrdev);
 884         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
 885         return 0;
 886 }
 887
 888 /* Somewhat of a cross file organization violation - ioctls here are actually
 889  * event related */
 890 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 891 {
 892         struct iio_dev *indio_dev = filp->private_data;
 893         int __user *ip = (int __user *)arg;
 894         int fd;
 895
 896         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 897                 fd = iio_event_getfd(indio_dev);
 898                 if (copy_to_user(ip, &fd, sizeof(fd)))
 899                         return -EFAULT;
 900                 return 0;
 901         }
 902         return -EINVAL;
 903 }
 904
 905 static const struct file_operations iio_buffer_fileops = {
 906         .read = iio_buffer_read_first_n_outer_addr,
 907         .release = iio_chrdev_release,
 908         .open = iio_chrdev_open,
 909         .poll = iio_buffer_poll_addr,
 910         .owner = THIS_MODULE,
 911         .llseek = noop_llseek,
 912         .unlocked_ioctl = iio_ioctl,
 913         .compat_ioctl = iio_ioctl,
 914 };
 915
 916 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
 917
 918 int iio_device_register(struct iio_dev *indio_dev)
 919 {
 920         int ret;
 921
 922         /* configure elements for the chrdev */
 923         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
 924
 925         ret = iio_device_register_debugfs(indio_dev);
 926         if (ret) {
 927                 dev_err(indio_dev->dev.parent,
 928                         "Failed to register debugfs interfaces\n");
 929                 goto error_ret;
 930         }
 931         ret = iio_device_register_sysfs(indio_dev);
 932         if (ret) {
 933                 dev_err(indio_dev->dev.parent,
 934                         "Failed to register sysfs interfaces\n");
 935                 goto error_unreg_debugfs;
 936         }
 937         ret = iio_device_register_eventset(indio_dev);
 938         if (ret) {
 939                 dev_err(indio_dev->dev.parent,
 940                         "Failed to register event set\n");
 941                 goto error_free_sysfs;
 942         }
 943         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 944                 iio_device_register_trigger_consumer(indio_dev);
 945
 946         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
 947                 indio_dev->setup_ops == NULL)
 948                 indio_dev->setup_ops = &noop_ring_setup_ops;
 949
 950         ret = device_add(&indio_dev->dev);
 951         if (ret < 0)
 952                 goto error_unreg_eventset;
 953         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 954         indio_dev->chrdev.owner = indio_dev->info->driver_module;
 955         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 956         if (ret < 0)
 957                 goto error_del_device;
 958         return 0;
 959
 960 error_del_device:
 961         device_del(&indio_dev->dev);
 962 error_unreg_eventset:
 963         iio_device_unregister_eventset(indio_dev);
 964 error_free_sysfs:
 965         iio_device_unregister_sysfs(indio_dev);
 966 error_unreg_debugfs:
 967         iio_device_unregister_debugfs(indio_dev);
 968 error_ret:
 969         return ret;
 970 }
 971 EXPORT_SYMBOL(iio_device_register);
 972
 973 void iio_device_unregister(struct iio_dev *indio_dev)
 974 {
 975         mutex_lock(&indio_dev->info_exist_lock);
 976         indio_dev->info = NULL;
 977         mutex_unlock(&indio_dev->info_exist_lock);
 978         device_del(&indio_dev->dev);
 979 }
 980 EXPORT_SYMBOL(iio_device_unregister);
 981 subsys_initcall(iio_init);
 982 module_exit(iio_exit);
 983
 984 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 985 MODULE_DESCRIPTION("Industrial I/O core");
 986 MODULE_LICENSE("GPL");