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         unsigned long long tmp;
 370         int val, val2;
 371         bool scale_db = false;
 372         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 373                                             &val, &val2, this_attr->address);
 374
 375         if (ret < 0)
 376                 return ret;
 377
 378         switch (ret) {
 379         case IIO_VAL_INT:
 380                 return sprintf(buf, "%d\n", val);
 381         case IIO_VAL_INT_PLUS_MICRO_DB:
 382                 scale_db = true;
 383         case IIO_VAL_INT_PLUS_MICRO:
 384                 if (val2 < 0)
 385                         return sprintf(buf, "-%d.%06u%s\n", val, -val2,
 386                                 scale_db ? " dB" : "");
 387                 else
 388                         return sprintf(buf, "%d.%06u%s\n", val, val2,
 389                                 scale_db ? " dB" : "");
 390         case IIO_VAL_INT_PLUS_NANO:
 391                 if (val2 < 0)
 392                         return sprintf(buf, "-%d.%09u\n", val, -val2);
 393                 else
 394                         return sprintf(buf, "%d.%09u\n", val, val2);
 395         case IIO_VAL_FRACTIONAL:
 396                 tmp = div_s64((s64)val * 1000000000LL, val2);
 397                 val2 = do_div(tmp, 1000000000LL);
 398                 val = tmp;
 399                 return sprintf(buf, "%d.%09u\n", val, val2);
 400         default:
 401                 return 0;
 402         }
 403 }
 404
 405 static ssize_t iio_write_channel_info(struct device *dev,
 406                                       struct device_attribute *attr,
 407                                       const char *buf,
 408                                       size_t len)
 409 {
 410         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 411         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 412         int ret, integer = 0, fract = 0, fract_mult = 100000;
 413         bool integer_part = true, negative = false;
 414
 415         /* Assumes decimal - precision based on number of digits */
 416         if (!indio_dev->info->write_raw)
 417                 return -EINVAL;
 418
 419         if (indio_dev->info->write_raw_get_fmt)
 420                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 421                         this_attr->c, this_attr->address)) {
 422                 case IIO_VAL_INT_PLUS_MICRO:
 423                         fract_mult = 100000;
 424                         break;
 425                 case IIO_VAL_INT_PLUS_NANO:
 426                         fract_mult = 100000000;
 427                         break;
 428                 default:
 429                         return -EINVAL;
 430                 }
 431
 432         if (buf[0] == '-') {
 433                 negative = true;
 434                 buf++;
 435         }
 436
 437         while (*buf) {
 438                 if ('0' <= *buf && *buf <= '9') {
 439                         if (integer_part)
 440                                 integer = integer*10 + *buf - '0';
 441                         else {
 442                                 fract += fract_mult*(*buf - '0');
 443                                 if (fract_mult == 1)
 444                                         break;
 445                                 fract_mult /= 10;
 446                         }
 447                 } else if (*buf == '\n') {
 448                         if (*(buf + 1) == '\0')
 449                                 break;
 450                         else
 451                                 return -EINVAL;
 452                 } else if (*buf == '.') {
 453                         integer_part = false;
 454                 } else {
 455                         return -EINVAL;
 456                 }
 457                 buf++;
 458         }
 459         if (negative) {
 460                 if (integer)
 461                         integer = -integer;
 462                 else
 463                         fract = -fract;
 464         }
 465
 466         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 467                                          integer, fract, this_attr->address);
 468         if (ret)
 469                 return ret;
 470
 471         return len;
 472 }
 473
 474 static
 475 int __iio_device_attr_init(struct device_attribute *dev_attr,
 476                            const char *postfix,
 477                            struct iio_chan_spec const *chan,
 478                            ssize_t (*readfunc)(struct device *dev,
 479                                                struct device_attribute *attr,
 480                                                char *buf),
 481                            ssize_t (*writefunc)(struct device *dev,
 482                                                 struct device_attribute *attr,
 483                                                 const char *buf,
 484                                                 size_t len),
 485                            bool generic)
 486 {
 487         int ret;
 488         char *name_format, *full_postfix;
 489         sysfs_attr_init(&dev_attr->attr);
 490
 491         /* Build up postfix of <extend_name>_<modifier>_postfix */
 492         if (chan->modified && !generic) {
 493                 if (chan->extend_name)
 494                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 495                                                  iio_modifier_names[chan
 496                                                                     ->channel2],
 497                                                  chan->extend_name,
 498                                                  postfix);
 499                 else
 500                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 501                                                  iio_modifier_names[chan
 502                                                                     ->channel2],
 503                                                  postfix);
 504         } else {
 505                 if (chan->extend_name == NULL)
 506                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 507                 else
 508                         full_postfix = kasprintf(GFP_KERNEL,
 509                                                  "%s_%s",
 510                                                  chan->extend_name,
 511                                                  postfix);
 512         }
 513         if (full_postfix == NULL) {
 514                 ret = -ENOMEM;
 515                 goto error_ret;
 516         }
 517
 518         if (chan->differential) { /* Differential can not have modifier */
 519                 if (generic)
 520                         name_format
 521                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 522                                             iio_direction[chan->output],
 523                                             iio_chan_type_name_spec[chan->type],
 524                                             iio_chan_type_name_spec[chan->type],
 525                                             full_postfix);
 526                 else if (chan->indexed)
 527                         name_format
 528                                 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
 529                                             iio_direction[chan->output],
 530                                             iio_chan_type_name_spec[chan->type],
 531                                             chan->channel,
 532                                             iio_chan_type_name_spec[chan->type],
 533                                             chan->channel2,
 534                                             full_postfix);
 535                 else {
 536                         WARN_ON("Differential channels must be indexed\n");
 537                         ret = -EINVAL;
 538                         goto error_free_full_postfix;
 539                 }
 540         } else { /* Single ended */
 541                 if (generic)
 542                         name_format
 543                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 544                                             iio_direction[chan->output],
 545                                             iio_chan_type_name_spec[chan->type],
 546                                             full_postfix);
 547                 else if (chan->indexed)
 548                         name_format
 549                                 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 550                                             iio_direction[chan->output],
 551                                             iio_chan_type_name_spec[chan->type],
 552                                             chan->channel,
 553                                             full_postfix);
 554                 else
 555                         name_format
 556                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 557                                             iio_direction[chan->output],
 558                                             iio_chan_type_name_spec[chan->type],
 559                                             full_postfix);
 560         }
 561         if (name_format == NULL) {
 562                 ret = -ENOMEM;
 563                 goto error_free_full_postfix;
 564         }
 565         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 566                                         name_format,
 567                                         chan->channel,
 568                                         chan->channel2);
 569         if (dev_attr->attr.name == NULL) {
 570                 ret = -ENOMEM;
 571                 goto error_free_name_format;
 572         }
 573
 574         if (readfunc) {
 575                 dev_attr->attr.mode |= S_IRUGO;
 576                 dev_attr->show = readfunc;
 577         }
 578
 579         if (writefunc) {
 580                 dev_attr->attr.mode |= S_IWUSR;
 581                 dev_attr->store = writefunc;
 582         }
 583         kfree(name_format);
 584         kfree(full_postfix);
 585
 586         return 0;
 587
 588 error_free_name_format:
 589         kfree(name_format);
 590 error_free_full_postfix:
 591         kfree(full_postfix);
 592 error_ret:
 593         return ret;
 594 }
 595
 596 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 597 {
 598         kfree(dev_attr->attr.name);
 599 }
 600
 601 int __iio_add_chan_devattr(const char *postfix,
 602                            struct iio_chan_spec const *chan,
 603                            ssize_t (*readfunc)(struct device *dev,
 604                                                struct device_attribute *attr,
 605                                                char *buf),
 606                            ssize_t (*writefunc)(struct device *dev,
 607                                                 struct device_attribute *attr,
 608                                                 const char *buf,
 609                                                 size_t len),
 610                            u64 mask,
 611                            bool generic,
 612                            struct device *dev,
 613                            struct list_head *attr_list)
 614 {
 615         int ret;
 616         struct iio_dev_attr *iio_attr, *t;
 617
 618         iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
 619         if (iio_attr == NULL) {
 620                 ret = -ENOMEM;
 621                 goto error_ret;
 622         }
 623         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 624                                      postfix, chan,
 625                                      readfunc, writefunc, generic);
 626         if (ret)
 627                 goto error_iio_dev_attr_free;
 628         iio_attr->c = chan;
 629         iio_attr->address = mask;
 630         list_for_each_entry(t, attr_list, l)
 631                 if (strcmp(t->dev_attr.attr.name,
 632                            iio_attr->dev_attr.attr.name) == 0) {
 633                         if (!generic)
 634                                 dev_err(dev, "tried to double register : %s\n",
 635                                         t->dev_attr.attr.name);
 636                         ret = -EBUSY;
 637                         goto error_device_attr_deinit;
 638                 }
 639         list_add(&iio_attr->l, attr_list);
 640
 641         return 0;
 642
 643 error_device_attr_deinit:
 644         __iio_device_attr_deinit(&iio_attr->dev_attr);
 645 error_iio_dev_attr_free:
 646         kfree(iio_attr);
 647 error_ret:
 648         return ret;
 649 }
 650
 651 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 652                                         struct iio_chan_spec const *chan)
 653 {
 654         int ret, attrcount = 0;
 655         int i;
 656         const struct iio_chan_spec_ext_info *ext_info;
 657
 658         if (chan->channel < 0)
 659                 return 0;
 660         for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
 661                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
 662                                              chan,
 663                                              &iio_read_channel_info,
 664                                              &iio_write_channel_info,
 665                                              i/2,
 666                                              !(i%2),
 667                                              &indio_dev->dev,
 668                                              &indio_dev->channel_attr_list);
 669                 if (ret == -EBUSY && (i%2 == 0)) {
 670                         ret = 0;
 671                         continue;
 672                 }
 673                 if (ret < 0)
 674                         goto error_ret;
 675                 attrcount++;
 676         }
 677
 678         if (chan->ext_info) {
 679                 unsigned int i = 0;
 680                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 681                         ret = __iio_add_chan_devattr(ext_info->name,
 682                                         chan,
 683                                         ext_info->read ?
 684                                             &iio_read_channel_ext_info : NULL,
 685                                         ext_info->write ?
 686                                             &iio_write_channel_ext_info : NULL,
 687                                         i,
 688                                         ext_info->shared,
 689                                         &indio_dev->dev,
 690                                         &indio_dev->channel_attr_list);
 691                         i++;
 692                         if (ret == -EBUSY && ext_info->shared)
 693                                 continue;
 694
 695                         if (ret)
 696                                 goto error_ret;
 697
 698                         attrcount++;
 699                 }
 700         }
 701
 702         ret = attrcount;
 703 error_ret:
 704         return ret;
 705 }
 706
 707 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
 708                                                  struct iio_dev_attr *p)
 709 {
 710         kfree(p->dev_attr.attr.name);
 711         kfree(p);
 712 }
 713
 714 static ssize_t iio_show_dev_name(struct device *dev,
 715                                  struct device_attribute *attr,
 716                                  char *buf)
 717 {
 718         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 719         return sprintf(buf, "%s\n", indio_dev->name);
 720 }
 721
 722 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 723
 724 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 725 {
 726         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 727         struct iio_dev_attr *p, *n;
 728         struct attribute **attr;
 729
 730         /* First count elements in any existing group */
 731         if (indio_dev->info->attrs) {
 732                 attr = indio_dev->info->attrs->attrs;
 733                 while (*attr++ != NULL)
 734                         attrcount_orig++;
 735         }
 736         attrcount = attrcount_orig;
 737         /*
 738          * New channel registration method - relies on the fact a group does
 739          * not need to be initialized if its name is NULL.
 740          */
 741         if (indio_dev->channels)
 742                 for (i = 0; i < indio_dev->num_channels; i++) {
 743                         ret = iio_device_add_channel_sysfs(indio_dev,
 744                                                            &indio_dev
 745                                                            ->channels[i]);
 746                         if (ret < 0)
 747                                 goto error_clear_attrs;
 748                         attrcount += ret;
 749                 }
 750
 751         if (indio_dev->name)
 752                 attrcount++;
 753
 754         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 755                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 756                                                    GFP_KERNEL);
 757         if (indio_dev->chan_attr_group.attrs == NULL) {
 758                 ret = -ENOMEM;
 759                 goto error_clear_attrs;
 760         }
 761         /* Copy across original attributes */
 762         if (indio_dev->info->attrs)
 763                 memcpy(indio_dev->chan_attr_group.attrs,
 764                        indio_dev->info->attrs->attrs,
 765                        sizeof(indio_dev->chan_attr_group.attrs[0])
 766                        *attrcount_orig);
 767         attrn = attrcount_orig;
 768         /* Add all elements from the list. */
 769         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 770                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 771         if (indio_dev->name)
 772                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 773
 774         indio_dev->groups[indio_dev->groupcounter++] =
 775                 &indio_dev->chan_attr_group;
 776
 777         return 0;
 778
 779 error_clear_attrs:
 780         list_for_each_entry_safe(p, n,
 781                                  &indio_dev->channel_attr_list, l) {
 782                 list_del(&p->l);
 783                 iio_device_remove_and_free_read_attr(indio_dev, p);
 784         }
 785
 786         return ret;
 787 }
 788
 789 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 790 {
 791
 792         struct iio_dev_attr *p, *n;
 793
 794         list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
 795                 list_del(&p->l);
 796                 iio_device_remove_and_free_read_attr(indio_dev, p);
 797         }
 798         kfree(indio_dev->chan_attr_group.attrs);
 799 }
 800
 801 static void iio_dev_release(struct device *device)
 802 {
 803         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 804         if (indio_dev->chrdev.dev)
 805                 cdev_del(&indio_dev->chrdev);
 806         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 807                 iio_device_unregister_trigger_consumer(indio_dev);
 808         iio_device_unregister_eventset(indio_dev);
 809         iio_device_unregister_sysfs(indio_dev);
 810         iio_device_unregister_debugfs(indio_dev);
 811
 812         ida_simple_remove(&iio_ida, indio_dev->id);
 813         kfree(indio_dev);
 814 }
 815
 816 static struct device_type iio_dev_type = {
 817         .name = "iio_device",
 818         .release = iio_dev_release,
 819 };
 820
 821 struct iio_dev *iio_device_alloc(int sizeof_priv)
 822 {
 823         struct iio_dev *dev;
 824         size_t alloc_size;
 825
 826         alloc_size = sizeof(struct iio_dev);
 827         if (sizeof_priv) {
 828                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 829                 alloc_size += sizeof_priv;
 830         }
 831         /* ensure 32-byte alignment of whole construct ? */
 832         alloc_size += IIO_ALIGN - 1;
 833
 834         dev = kzalloc(alloc_size, GFP_KERNEL);
 835
 836         if (dev) {
 837                 dev->dev.groups = dev->groups;
 838                 dev->dev.type = &iio_dev_type;
 839                 dev->dev.bus = &iio_bus_type;
 840                 device_initialize(&dev->dev);
 841                 dev_set_drvdata(&dev->dev, (void *)dev);
 842                 mutex_init(&dev->mlock);
 843                 mutex_init(&dev->info_exist_lock);
 844                 INIT_LIST_HEAD(&dev->channel_attr_list);
 845
 846                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 847                 if (dev->id < 0) {
 848                         /* cannot use a dev_err as the name isn't available */
 849                         printk(KERN_ERR "Failed to get id\n");
 850                         kfree(dev);
 851                         return NULL;
 852                 }
 853                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 854         }
 855
 856         return dev;
 857 }
 858 EXPORT_SYMBOL(iio_device_alloc);
 859
 860 void iio_device_free(struct iio_dev *dev)
 861 {
 862         if (dev)
 863                 put_device(&dev->dev);
 864 }
 865 EXPORT_SYMBOL(iio_device_free);
 866
 867 /**
 868  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
 869  **/
 870 static int iio_chrdev_open(struct inode *inode, struct file *filp)
 871 {
 872         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 873                                                 struct iio_dev, chrdev);
 874
 875         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 876                 return -EBUSY;
 877
 878         filp->private_data = indio_dev;
 879
 880         return 0;
 881 }
 882
 883 /**
 884  * iio_chrdev_release() - chrdev file close buffer access and ioctls
 885  **/
 886 static int iio_chrdev_release(struct inode *inode, struct file *filp)
 887 {
 888         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 889                                                 struct iio_dev, chrdev);
 890         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
 891         return 0;
 892 }
 893
 894 /* Somewhat of a cross file organization violation - ioctls here are actually
 895  * event related */
 896 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 897 {
 898         struct iio_dev *indio_dev = filp->private_data;
 899         int __user *ip = (int __user *)arg;
 900         int fd;
 901
 902         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 903                 fd = iio_event_getfd(indio_dev);
 904                 if (copy_to_user(ip, &fd, sizeof(fd)))
 905                         return -EFAULT;
 906                 return 0;
 907         }
 908         return -EINVAL;
 909 }
 910
 911 static const struct file_operations iio_buffer_fileops = {
 912         .read = iio_buffer_read_first_n_outer_addr,
 913         .release = iio_chrdev_release,
 914         .open = iio_chrdev_open,
 915         .poll = iio_buffer_poll_addr,
 916         .owner = THIS_MODULE,
 917         .llseek = noop_llseek,
 918         .unlocked_ioctl = iio_ioctl,
 919         .compat_ioctl = iio_ioctl,
 920 };
 921
 922 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
 923
 924 int iio_device_register(struct iio_dev *indio_dev)
 925 {
 926         int ret;
 927
 928         /* configure elements for the chrdev */
 929         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
 930
 931         ret = iio_device_register_debugfs(indio_dev);
 932         if (ret) {
 933                 dev_err(indio_dev->dev.parent,
 934                         "Failed to register debugfs interfaces\n");
 935                 goto error_ret;
 936         }
 937         ret = iio_device_register_sysfs(indio_dev);
 938         if (ret) {
 939                 dev_err(indio_dev->dev.parent,
 940                         "Failed to register sysfs interfaces\n");
 941                 goto error_unreg_debugfs;
 942         }
 943         ret = iio_device_register_eventset(indio_dev);
 944         if (ret) {
 945                 dev_err(indio_dev->dev.parent,
 946                         "Failed to register event set\n");
 947                 goto error_free_sysfs;
 948         }
 949         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 950                 iio_device_register_trigger_consumer(indio_dev);
 951
 952         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
 953                 indio_dev->setup_ops == NULL)
 954                 indio_dev->setup_ops = &noop_ring_setup_ops;
 955
 956         ret = device_add(&indio_dev->dev);
 957         if (ret < 0)
 958                 goto error_unreg_eventset;
 959         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 960         indio_dev->chrdev.owner = indio_dev->info->driver_module;
 961         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 962         if (ret < 0)
 963                 goto error_del_device;
 964         return 0;
 965
 966 error_del_device:
 967         device_del(&indio_dev->dev);
 968 error_unreg_eventset:
 969         iio_device_unregister_eventset(indio_dev);
 970 error_free_sysfs:
 971         iio_device_unregister_sysfs(indio_dev);
 972 error_unreg_debugfs:
 973         iio_device_unregister_debugfs(indio_dev);
 974 error_ret:
 975         return ret;
 976 }
 977 EXPORT_SYMBOL(iio_device_register);
 978
 979 void iio_device_unregister(struct iio_dev *indio_dev)
 980 {
 981         mutex_lock(&indio_dev->info_exist_lock);
 982         indio_dev->info = NULL;
 983         mutex_unlock(&indio_dev->info_exist_lock);
 984         device_del(&indio_dev->dev);
 985 }
 986 EXPORT_SYMBOL(iio_device_unregister);
 987 subsys_initcall(iio_init);
 988 module_exit(iio_exit);
 989
 990 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 991 MODULE_DESCRIPTION("Industrial I/O core");
 992 MODULE_LICENSE("GPL");