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         [IIO_PRESSURE] = "pressure",
  69 };
  70
  71 static const char * const iio_modifier_names[] = {
  72         [IIO_MOD_X] = "x",
  73         [IIO_MOD_Y] = "y",
  74         [IIO_MOD_Z] = "z",
  75         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
  76         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
  77         [IIO_MOD_LIGHT_BOTH] = "both",
  78         [IIO_MOD_LIGHT_IR] = "ir",
  79         [IIO_MOD_LIGHT_CLEAR] = "clear",
  80         [IIO_MOD_LIGHT_RED] = "red",
  81         [IIO_MOD_LIGHT_GREEN] = "green",
  82         [IIO_MOD_LIGHT_BLUE] = "blue",
  83 };
  84
  85 /* relies on pairs of these shared then separate */
  86 static const char * const iio_chan_info_postfix[] = {
  87         [IIO_CHAN_INFO_RAW] = "raw",
  88         [IIO_CHAN_INFO_PROCESSED] = "input",
  89         [IIO_CHAN_INFO_SCALE] = "scale",
  90         [IIO_CHAN_INFO_OFFSET] = "offset",
  91         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
  92         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
  93         [IIO_CHAN_INFO_PEAK] = "peak_raw",
  94         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
  95         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
  96         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
  97         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
  98         = "filter_low_pass_3db_frequency",
  99         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 100         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 101         [IIO_CHAN_INFO_PHASE] = "phase",
 102         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 103         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 104 };
 105
 106 const struct iio_chan_spec
 107 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 108 {
 109         int i;
 110
 111         for (i = 0; i < indio_dev->num_channels; i++)
 112                 if (indio_dev->channels[i].scan_index == si)
 113                         return &indio_dev->channels[i];
 114         return NULL;
 115 }
 116
 117 /* This turns up an awful lot */
 118 ssize_t iio_read_const_attr(struct device *dev,
 119                             struct device_attribute *attr,
 120                             char *buf)
 121 {
 122         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 123 }
 124 EXPORT_SYMBOL(iio_read_const_attr);
 125
 126 static int __init iio_init(void)
 127 {
 128         int ret;
 129
 130         /* Register sysfs bus */
 131         ret  = bus_register(&iio_bus_type);
 132         if (ret < 0) {
 133                 printk(KERN_ERR
 134                        "%s could not register bus type\n",
 135                         __FILE__);
 136                 goto error_nothing;
 137         }
 138
 139         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 140         if (ret < 0) {
 141                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 142                        __FILE__);
 143                 goto error_unregister_bus_type;
 144         }
 145
 146         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 147
 148         return 0;
 149
 150 error_unregister_bus_type:
 151         bus_unregister(&iio_bus_type);
 152 error_nothing:
 153         return ret;
 154 }
 155
 156 static void __exit iio_exit(void)
 157 {
 158         if (iio_devt)
 159                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 160         bus_unregister(&iio_bus_type);
 161         debugfs_remove(iio_debugfs_dentry);
 162 }
 163
 164 #if defined(CONFIG_DEBUG_FS)
 165 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 166                               size_t count, loff_t *ppos)
 167 {
 168         struct iio_dev *indio_dev = file->private_data;
 169         char buf[20];
 170         unsigned val = 0;
 171         ssize_t len;
 172         int ret;
 173
 174         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 175                                                   indio_dev->cached_reg_addr,
 176                                                   0, &val);
 177         if (ret)
 178                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 179
 180         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 181
 182         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 183 }
 184
 185 static ssize_t iio_debugfs_write_reg(struct file *file,
 186                      const char __user *userbuf, size_t count, loff_t *ppos)
 187 {
 188         struct iio_dev *indio_dev = file->private_data;
 189         unsigned reg, val;
 190         char buf[80];
 191         int ret;
 192
 193         count = min_t(size_t, count, (sizeof(buf)-1));
 194         if (copy_from_user(buf, userbuf, count))
 195                 return -EFAULT;
 196
 197         buf[count] = 0;
 198
 199         ret = sscanf(buf, "%i %i", &reg, &val);
 200
 201         switch (ret) {
 202         case 1:
 203                 indio_dev->cached_reg_addr = reg;
 204                 break;
 205         case 2:
 206                 indio_dev->cached_reg_addr = reg;
 207                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 208                                                           val, NULL);
 209                 if (ret) {
 210                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 211                                 __func__);
 212                         return ret;
 213                 }
 214                 break;
 215         default:
 216                 return -EINVAL;
 217         }
 218
 219         return count;
 220 }
 221
 222 static const struct file_operations iio_debugfs_reg_fops = {
 223         .open = simple_open,
 224         .read = iio_debugfs_read_reg,
 225         .write = iio_debugfs_write_reg,
 226 };
 227
 228 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 229 {
 230         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 231 }
 232
 233 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 234 {
 235         struct dentry *d;
 236
 237         if (indio_dev->info->debugfs_reg_access == NULL)
 238                 return 0;
 239
 240         if (!iio_debugfs_dentry)
 241                 return 0;
 242
 243         indio_dev->debugfs_dentry =
 244                 debugfs_create_dir(dev_name(&indio_dev->dev),
 245                                    iio_debugfs_dentry);
 246         if (indio_dev->debugfs_dentry == NULL) {
 247                 dev_warn(indio_dev->dev.parent,
 248                          "Failed to create debugfs directory\n");
 249                 return -EFAULT;
 250         }
 251
 252         d = debugfs_create_file("direct_reg_access", 0644,
 253                                 indio_dev->debugfs_dentry,
 254                                 indio_dev, &iio_debugfs_reg_fops);
 255         if (!d) {
 256                 iio_device_unregister_debugfs(indio_dev);
 257                 return -ENOMEM;
 258         }
 259
 260         return 0;
 261 }
 262 #else
 263 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 264 {
 265         return 0;
 266 }
 267
 268 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 269 {
 270 }
 271 #endif /* CONFIG_DEBUG_FS */
 272
 273 static ssize_t iio_read_channel_ext_info(struct device *dev,
 274                                      struct device_attribute *attr,
 275                                      char *buf)
 276 {
 277         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 278         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 279         const struct iio_chan_spec_ext_info *ext_info;
 280
 281         ext_info = &this_attr->c->ext_info[this_attr->address];
 282
 283         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 284 }
 285
 286 static ssize_t iio_write_channel_ext_info(struct device *dev,
 287                                      struct device_attribute *attr,
 288                                      const char *buf,
 289                                          size_t len)
 290 {
 291         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 292         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 293         const struct iio_chan_spec_ext_info *ext_info;
 294
 295         ext_info = &this_attr->c->ext_info[this_attr->address];
 296
 297         return ext_info->write(indio_dev, ext_info->private,
 298                                this_attr->c, buf, len);
 299 }
 300
 301 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 302         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 303 {
 304         const struct iio_enum *e = (const struct iio_enum *)priv;
 305         unsigned int i;
 306         size_t len = 0;
 307
 308         if (!e->num_items)
 309                 return 0;
 310
 311         for (i = 0; i < e->num_items; ++i)
 312                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 313
 314         /* replace last space with a newline */
 315         buf[len - 1] = '\n';
 316
 317         return len;
 318 }
 319 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 320
 321 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 322         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 323 {
 324         const struct iio_enum *e = (const struct iio_enum *)priv;
 325         int i;
 326
 327         if (!e->get)
 328                 return -EINVAL;
 329
 330         i = e->get(indio_dev, chan);
 331         if (i < 0)
 332                 return i;
 333         else if (i >= e->num_items)
 334                 return -EINVAL;
 335
 336         return sprintf(buf, "%s\n", e->items[i]);
 337 }
 338 EXPORT_SYMBOL_GPL(iio_enum_read);
 339
 340 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 341         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 342         size_t len)
 343 {
 344         const struct iio_enum *e = (const struct iio_enum *)priv;
 345         unsigned int i;
 346         int ret;
 347
 348         if (!e->set)
 349                 return -EINVAL;
 350
 351         for (i = 0; i < e->num_items; i++) {
 352                 if (sysfs_streq(buf, e->items[i]))
 353                         break;
 354         }
 355
 356         if (i == e->num_items)
 357                 return -EINVAL;
 358
 359         ret = e->set(indio_dev, chan, i);
 360         return ret ? ret : len;
 361 }
 362 EXPORT_SYMBOL_GPL(iio_enum_write);
 363
 364 static ssize_t iio_read_channel_info(struct device *dev,
 365                                      struct device_attribute *attr,
 366                                      char *buf)
 367 {
 368         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 369         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 370         unsigned long long tmp;
 371         int val, val2;
 372         bool scale_db = false;
 373         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 374                                             &val, &val2, this_attr->address);
 375
 376         if (ret < 0)
 377                 return ret;
 378
 379         switch (ret) {
 380         case IIO_VAL_INT:
 381                 return sprintf(buf, "%d\n", val);
 382         case IIO_VAL_INT_PLUS_MICRO_DB:
 383                 scale_db = true;
 384         case IIO_VAL_INT_PLUS_MICRO:
 385                 if (val2 < 0)
 386                         return sprintf(buf, "-%d.%06u%s\n", val, -val2,
 387                                 scale_db ? " dB" : "");
 388                 else
 389                         return sprintf(buf, "%d.%06u%s\n", val, val2,
 390                                 scale_db ? " dB" : "");
 391         case IIO_VAL_INT_PLUS_NANO:
 392                 if (val2 < 0)
 393                         return sprintf(buf, "-%d.%09u\n", val, -val2);
 394                 else
 395                         return sprintf(buf, "%d.%09u\n", val, val2);
 396         case IIO_VAL_FRACTIONAL:
 397                 tmp = div_s64((s64)val * 1000000000LL, val2);
 398                 val2 = do_div(tmp, 1000000000LL);
 399                 val = tmp;
 400                 return sprintf(buf, "%d.%09u\n", val, val2);
 401         case IIO_VAL_FRACTIONAL_LOG2:
 402                 tmp = (s64)val * 1000000000LL >> val2;
 403                 val2 = do_div(tmp, 1000000000LL);
 404                 val = tmp;
 405                 return sprintf(buf, "%d.%09u\n", val, val2);
 406         default:
 407                 return 0;
 408         }
 409 }
 410
 411 /**
 412  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 413  * @str: The string to parse
 414  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 415  * @integer: The integer part of the number
 416  * @fract: The fractional part of the number
 417  *
 418  * Returns 0 on success, or a negative error code if the string could not be
 419  * parsed.
 420  */
 421 int iio_str_to_fixpoint(const char *str, int fract_mult,
 422         int *integer, int *fract)
 423 {
 424         int i = 0, f = 0;
 425         bool integer_part = true, negative = false;
 426
 427         if (str[0] == '-') {
 428                 negative = true;
 429                 str++;
 430         } else if (str[0] == '+') {
 431                 str++;
 432         }
 433
 434         while (*str) {
 435                 if ('0' <= *str && *str <= '9') {
 436                         if (integer_part) {
 437                                 i = i * 10 + *str - '0';
 438                         } else {
 439                                 f += fract_mult * (*str - '0');
 440                                 fract_mult /= 10;
 441                         }
 442                 } else if (*str == '\n') {
 443                         if (*(str + 1) == '\0')
 444                                 break;
 445                         else
 446                                 return -EINVAL;
 447                 } else if (*str == '.' && integer_part) {
 448                         integer_part = false;
 449                 } else {
 450                         return -EINVAL;
 451                 }
 452                 str++;
 453         }
 454
 455         if (negative) {
 456                 if (i)
 457                         i = -i;
 458                 else
 459                         f = -f;
 460         }
 461
 462         *integer = i;
 463         *fract = f;
 464
 465         return 0;
 466 }
 467 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 468
 469 static ssize_t iio_write_channel_info(struct device *dev,
 470                                       struct device_attribute *attr,
 471                                       const char *buf,
 472                                       size_t len)
 473 {
 474         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 475         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 476         int ret, fract_mult = 100000;
 477         int integer, fract;
 478
 479         /* Assumes decimal - precision based on number of digits */
 480         if (!indio_dev->info->write_raw)
 481                 return -EINVAL;
 482
 483         if (indio_dev->info->write_raw_get_fmt)
 484                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 485                         this_attr->c, this_attr->address)) {
 486                 case IIO_VAL_INT_PLUS_MICRO:
 487                         fract_mult = 100000;
 488                         break;
 489                 case IIO_VAL_INT_PLUS_NANO:
 490                         fract_mult = 100000000;
 491                         break;
 492                 default:
 493                         return -EINVAL;
 494                 }
 495
 496         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 497         if (ret)
 498                 return ret;
 499
 500         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 501                                          integer, fract, this_attr->address);
 502         if (ret)
 503                 return ret;
 504
 505         return len;
 506 }
 507
 508 static
 509 int __iio_device_attr_init(struct device_attribute *dev_attr,
 510                            const char *postfix,
 511                            struct iio_chan_spec const *chan,
 512                            ssize_t (*readfunc)(struct device *dev,
 513                                                struct device_attribute *attr,
 514                                                char *buf),
 515                            ssize_t (*writefunc)(struct device *dev,
 516                                                 struct device_attribute *attr,
 517                                                 const char *buf,
 518                                                 size_t len),
 519                            bool generic)
 520 {
 521         int ret;
 522         char *name_format, *full_postfix;
 523         sysfs_attr_init(&dev_attr->attr);
 524
 525         /* Build up postfix of <extend_name>_<modifier>_postfix */
 526         if (chan->modified && !generic) {
 527                 if (chan->extend_name)
 528                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 529                                                  iio_modifier_names[chan
 530                                                                     ->channel2],
 531                                                  chan->extend_name,
 532                                                  postfix);
 533                 else
 534                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 535                                                  iio_modifier_names[chan
 536                                                                     ->channel2],
 537                                                  postfix);
 538         } else {
 539                 if (chan->extend_name == NULL)
 540                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 541                 else
 542                         full_postfix = kasprintf(GFP_KERNEL,
 543                                                  "%s_%s",
 544                                                  chan->extend_name,
 545                                                  postfix);
 546         }
 547         if (full_postfix == NULL) {
 548                 ret = -ENOMEM;
 549                 goto error_ret;
 550         }
 551
 552         if (chan->differential) { /* Differential can not have modifier */
 553                 if (generic)
 554                         name_format
 555                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 556                                             iio_direction[chan->output],
 557                                             iio_chan_type_name_spec[chan->type],
 558                                             iio_chan_type_name_spec[chan->type],
 559                                             full_postfix);
 560                 else if (chan->indexed)
 561                         name_format
 562                                 = kasprintf(GFP_KERNEL, "%s_%s%d-%s%d_%s",
 563                                             iio_direction[chan->output],
 564                                             iio_chan_type_name_spec[chan->type],
 565                                             chan->channel,
 566                                             iio_chan_type_name_spec[chan->type],
 567                                             chan->channel2,
 568                                             full_postfix);
 569                 else {
 570                         WARN_ON("Differential channels must be indexed\n");
 571                         ret = -EINVAL;
 572                         goto error_free_full_postfix;
 573                 }
 574         } else { /* Single ended */
 575                 if (generic)
 576                         name_format
 577                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 578                                             iio_direction[chan->output],
 579                                             iio_chan_type_name_spec[chan->type],
 580                                             full_postfix);
 581                 else if (chan->indexed)
 582                         name_format
 583                                 = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 584                                             iio_direction[chan->output],
 585                                             iio_chan_type_name_spec[chan->type],
 586                                             chan->channel,
 587                                             full_postfix);
 588                 else
 589                         name_format
 590                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 591                                             iio_direction[chan->output],
 592                                             iio_chan_type_name_spec[chan->type],
 593                                             full_postfix);
 594         }
 595         if (name_format == NULL) {
 596                 ret = -ENOMEM;
 597                 goto error_free_full_postfix;
 598         }
 599         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 600                                         name_format,
 601                                         chan->channel,
 602                                         chan->channel2);
 603         if (dev_attr->attr.name == NULL) {
 604                 ret = -ENOMEM;
 605                 goto error_free_name_format;
 606         }
 607
 608         if (readfunc) {
 609                 dev_attr->attr.mode |= S_IRUGO;
 610                 dev_attr->show = readfunc;
 611         }
 612
 613         if (writefunc) {
 614                 dev_attr->attr.mode |= S_IWUSR;
 615                 dev_attr->store = writefunc;
 616         }
 617         kfree(name_format);
 618         kfree(full_postfix);
 619
 620         return 0;
 621
 622 error_free_name_format:
 623         kfree(name_format);
 624 error_free_full_postfix:
 625         kfree(full_postfix);
 626 error_ret:
 627         return ret;
 628 }
 629
 630 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 631 {
 632         kfree(dev_attr->attr.name);
 633 }
 634
 635 int __iio_add_chan_devattr(const char *postfix,
 636                            struct iio_chan_spec const *chan,
 637                            ssize_t (*readfunc)(struct device *dev,
 638                                                struct device_attribute *attr,
 639                                                char *buf),
 640                            ssize_t (*writefunc)(struct device *dev,
 641                                                 struct device_attribute *attr,
 642                                                 const char *buf,
 643                                                 size_t len),
 644                            u64 mask,
 645                            bool generic,
 646                            struct device *dev,
 647                            struct list_head *attr_list)
 648 {
 649         int ret;
 650         struct iio_dev_attr *iio_attr, *t;
 651
 652         iio_attr = kzalloc(sizeof *iio_attr, GFP_KERNEL);
 653         if (iio_attr == NULL) {
 654                 ret = -ENOMEM;
 655                 goto error_ret;
 656         }
 657         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 658                                      postfix, chan,
 659                                      readfunc, writefunc, generic);
 660         if (ret)
 661                 goto error_iio_dev_attr_free;
 662         iio_attr->c = chan;
 663         iio_attr->address = mask;
 664         list_for_each_entry(t, attr_list, l)
 665                 if (strcmp(t->dev_attr.attr.name,
 666                            iio_attr->dev_attr.attr.name) == 0) {
 667                         if (!generic)
 668                                 dev_err(dev, "tried to double register : %s\n",
 669                                         t->dev_attr.attr.name);
 670                         ret = -EBUSY;
 671                         goto error_device_attr_deinit;
 672                 }
 673         list_add(&iio_attr->l, attr_list);
 674
 675         return 0;
 676
 677 error_device_attr_deinit:
 678         __iio_device_attr_deinit(&iio_attr->dev_attr);
 679 error_iio_dev_attr_free:
 680         kfree(iio_attr);
 681 error_ret:
 682         return ret;
 683 }
 684
 685 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 686                                         struct iio_chan_spec const *chan)
 687 {
 688         int ret, attrcount = 0;
 689         int i;
 690         const struct iio_chan_spec_ext_info *ext_info;
 691
 692         if (chan->channel < 0)
 693                 return 0;
 694         for_each_set_bit(i, &chan->info_mask, sizeof(long)*8) {
 695                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i/2],
 696                                              chan,
 697                                              &iio_read_channel_info,
 698                                              &iio_write_channel_info,
 699                                              i/2,
 700                                              !(i%2),
 701                                              &indio_dev->dev,
 702                                              &indio_dev->channel_attr_list);
 703                 if (ret == -EBUSY && (i%2 == 0)) {
 704                         ret = 0;
 705                         continue;
 706                 }
 707                 if (ret < 0)
 708                         goto error_ret;
 709                 attrcount++;
 710         }
 711
 712         if (chan->ext_info) {
 713                 unsigned int i = 0;
 714                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 715                         ret = __iio_add_chan_devattr(ext_info->name,
 716                                         chan,
 717                                         ext_info->read ?
 718                                             &iio_read_channel_ext_info : NULL,
 719                                         ext_info->write ?
 720                                             &iio_write_channel_ext_info : NULL,
 721                                         i,
 722                                         ext_info->shared,
 723                                         &indio_dev->dev,
 724                                         &indio_dev->channel_attr_list);
 725                         i++;
 726                         if (ret == -EBUSY && ext_info->shared)
 727                                 continue;
 728
 729                         if (ret)
 730                                 goto error_ret;
 731
 732                         attrcount++;
 733                 }
 734         }
 735
 736         ret = attrcount;
 737 error_ret:
 738         return ret;
 739 }
 740
 741 static void iio_device_remove_and_free_read_attr(struct iio_dev *indio_dev,
 742                                                  struct iio_dev_attr *p)
 743 {
 744         kfree(p->dev_attr.attr.name);
 745         kfree(p);
 746 }
 747
 748 static ssize_t iio_show_dev_name(struct device *dev,
 749                                  struct device_attribute *attr,
 750                                  char *buf)
 751 {
 752         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 753         return sprintf(buf, "%s\n", indio_dev->name);
 754 }
 755
 756 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 757
 758 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 759 {
 760         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 761         struct iio_dev_attr *p, *n;
 762         struct attribute **attr;
 763
 764         /* First count elements in any existing group */
 765         if (indio_dev->info->attrs) {
 766                 attr = indio_dev->info->attrs->attrs;
 767                 while (*attr++ != NULL)
 768                         attrcount_orig++;
 769         }
 770         attrcount = attrcount_orig;
 771         /*
 772          * New channel registration method - relies on the fact a group does
 773          * not need to be initialized if its name is NULL.
 774          */
 775         if (indio_dev->channels)
 776                 for (i = 0; i < indio_dev->num_channels; i++) {
 777                         ret = iio_device_add_channel_sysfs(indio_dev,
 778                                                            &indio_dev
 779                                                            ->channels[i]);
 780                         if (ret < 0)
 781                                 goto error_clear_attrs;
 782                         attrcount += ret;
 783                 }
 784
 785         if (indio_dev->name)
 786                 attrcount++;
 787
 788         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 789                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 790                                                    GFP_KERNEL);
 791         if (indio_dev->chan_attr_group.attrs == NULL) {
 792                 ret = -ENOMEM;
 793                 goto error_clear_attrs;
 794         }
 795         /* Copy across original attributes */
 796         if (indio_dev->info->attrs)
 797                 memcpy(indio_dev->chan_attr_group.attrs,
 798                        indio_dev->info->attrs->attrs,
 799                        sizeof(indio_dev->chan_attr_group.attrs[0])
 800                        *attrcount_orig);
 801         attrn = attrcount_orig;
 802         /* Add all elements from the list. */
 803         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 804                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 805         if (indio_dev->name)
 806                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 807
 808         indio_dev->groups[indio_dev->groupcounter++] =
 809                 &indio_dev->chan_attr_group;
 810
 811         return 0;
 812
 813 error_clear_attrs:
 814         list_for_each_entry_safe(p, n,
 815                                  &indio_dev->channel_attr_list, l) {
 816                 list_del(&p->l);
 817                 iio_device_remove_and_free_read_attr(indio_dev, p);
 818         }
 819
 820         return ret;
 821 }
 822
 823 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 824 {
 825
 826         struct iio_dev_attr *p, *n;
 827
 828         list_for_each_entry_safe(p, n, &indio_dev->channel_attr_list, l) {
 829                 list_del(&p->l);
 830                 iio_device_remove_and_free_read_attr(indio_dev, p);
 831         }
 832         kfree(indio_dev->chan_attr_group.attrs);
 833 }
 834
 835 static void iio_dev_release(struct device *device)
 836 {
 837         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 838         if (indio_dev->chrdev.dev)
 839                 cdev_del(&indio_dev->chrdev);
 840         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 841                 iio_device_unregister_trigger_consumer(indio_dev);
 842         iio_device_unregister_eventset(indio_dev);
 843         iio_device_unregister_sysfs(indio_dev);
 844         iio_device_unregister_debugfs(indio_dev);
 845
 846         ida_simple_remove(&iio_ida, indio_dev->id);
 847         kfree(indio_dev);
 848 }
 849
 850 static struct device_type iio_dev_type = {
 851         .name = "iio_device",
 852         .release = iio_dev_release,
 853 };
 854
 855 struct iio_dev *iio_device_alloc(int sizeof_priv)
 856 {
 857         struct iio_dev *dev;
 858         size_t alloc_size;
 859
 860         alloc_size = sizeof(struct iio_dev);
 861         if (sizeof_priv) {
 862                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 863                 alloc_size += sizeof_priv;
 864         }
 865         /* ensure 32-byte alignment of whole construct ? */
 866         alloc_size += IIO_ALIGN - 1;
 867
 868         dev = kzalloc(alloc_size, GFP_KERNEL);
 869
 870         if (dev) {
 871                 dev->dev.groups = dev->groups;
 872                 dev->dev.type = &iio_dev_type;
 873                 dev->dev.bus = &iio_bus_type;
 874                 device_initialize(&dev->dev);
 875                 dev_set_drvdata(&dev->dev, (void *)dev);
 876                 mutex_init(&dev->mlock);
 877                 mutex_init(&dev->info_exist_lock);
 878                 INIT_LIST_HEAD(&dev->channel_attr_list);
 879
 880                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 881                 if (dev->id < 0) {
 882                         /* cannot use a dev_err as the name isn't available */
 883                         printk(KERN_ERR "Failed to get id\n");
 884                         kfree(dev);
 885                         return NULL;
 886                 }
 887                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 888                 INIT_LIST_HEAD(&dev->buffer_list);
 889         }
 890
 891         return dev;
 892 }
 893 EXPORT_SYMBOL(iio_device_alloc);
 894
 895 void iio_device_free(struct iio_dev *dev)
 896 {
 897         if (dev)
 898                 put_device(&dev->dev);
 899 }
 900 EXPORT_SYMBOL(iio_device_free);
 901
 902 /**
 903  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
 904  **/
 905 static int iio_chrdev_open(struct inode *inode, struct file *filp)
 906 {
 907         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 908                                                 struct iio_dev, chrdev);
 909
 910         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
 911                 return -EBUSY;
 912
 913         filp->private_data = indio_dev;
 914
 915         return 0;
 916 }
 917
 918 /**
 919  * iio_chrdev_release() - chrdev file close buffer access and ioctls
 920  **/
 921 static int iio_chrdev_release(struct inode *inode, struct file *filp)
 922 {
 923         struct iio_dev *indio_dev = container_of(inode->i_cdev,
 924                                                 struct iio_dev, chrdev);
 925         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
 926         return 0;
 927 }
 928
 929 /* Somewhat of a cross file organization violation - ioctls here are actually
 930  * event related */
 931 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 932 {
 933         struct iio_dev *indio_dev = filp->private_data;
 934         int __user *ip = (int __user *)arg;
 935         int fd;
 936
 937         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
 938                 fd = iio_event_getfd(indio_dev);
 939                 if (copy_to_user(ip, &fd, sizeof(fd)))
 940                         return -EFAULT;
 941                 return 0;
 942         }
 943         return -EINVAL;
 944 }
 945
 946 static const struct file_operations iio_buffer_fileops = {
 947         .read = iio_buffer_read_first_n_outer_addr,
 948         .release = iio_chrdev_release,
 949         .open = iio_chrdev_open,
 950         .poll = iio_buffer_poll_addr,
 951         .owner = THIS_MODULE,
 952         .llseek = noop_llseek,
 953         .unlocked_ioctl = iio_ioctl,
 954         .compat_ioctl = iio_ioctl,
 955 };
 956
 957 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
 958
 959 int iio_device_register(struct iio_dev *indio_dev)
 960 {
 961         int ret;
 962
 963         /* configure elements for the chrdev */
 964         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
 965
 966         ret = iio_device_register_debugfs(indio_dev);
 967         if (ret) {
 968                 dev_err(indio_dev->dev.parent,
 969                         "Failed to register debugfs interfaces\n");
 970                 goto error_ret;
 971         }
 972         ret = iio_device_register_sysfs(indio_dev);
 973         if (ret) {
 974                 dev_err(indio_dev->dev.parent,
 975                         "Failed to register sysfs interfaces\n");
 976                 goto error_unreg_debugfs;
 977         }
 978         ret = iio_device_register_eventset(indio_dev);
 979         if (ret) {
 980                 dev_err(indio_dev->dev.parent,
 981                         "Failed to register event set\n");
 982                 goto error_free_sysfs;
 983         }
 984         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 985                 iio_device_register_trigger_consumer(indio_dev);
 986
 987         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
 988                 indio_dev->setup_ops == NULL)
 989                 indio_dev->setup_ops = &noop_ring_setup_ops;
 990
 991         ret = device_add(&indio_dev->dev);
 992         if (ret < 0)
 993                 goto error_unreg_eventset;
 994         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
 995         indio_dev->chrdev.owner = indio_dev->info->driver_module;
 996         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
 997         if (ret < 0)
 998                 goto error_del_device;
 999         return 0;
1000
1001 error_del_device:
1002         device_del(&indio_dev->dev);
1003 error_unreg_eventset:
1004         iio_device_unregister_eventset(indio_dev);
1005 error_free_sysfs:
1006         iio_device_unregister_sysfs(indio_dev);
1007 error_unreg_debugfs:
1008         iio_device_unregister_debugfs(indio_dev);
1009 error_ret:
1010         return ret;
1011 }
1012 EXPORT_SYMBOL(iio_device_register);
1013
1014 void iio_device_unregister(struct iio_dev *indio_dev)
1015 {
1016         mutex_lock(&indio_dev->info_exist_lock);
1017         indio_dev->info = NULL;
1018         mutex_unlock(&indio_dev->info_exist_lock);
1019         device_del(&indio_dev->dev);
1020 }
1021 EXPORT_SYMBOL(iio_device_unregister);
1022 subsys_initcall(iio_init);
1023 module_exit(iio_exit);
1024
1025 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1026 MODULE_DESCRIPTION("Industrial I/O core");
1027 MODULE_LICENSE("GPL");