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 #define pr_fmt(fmt) "iio-core: " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/idr.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19 #include <linux/device.h>
  20 #include <linux/fs.h>
  21 #include <linux/poll.h>
  22 #include <linux/sched.h>
  23 #include <linux/wait.h>
  24 #include <linux/cdev.h>
  25 #include <linux/slab.h>
  26 #include <linux/anon_inodes.h>
  27 #include <linux/debugfs.h>
  28 #include <linux/iio/iio.h>
  29 #include "iio_core.h"
  30 #include "iio_core_trigger.h"
  31 #include <linux/iio/sysfs.h>
  32 #include <linux/iio/events.h>
  33 #include <linux/iio/buffer.h>
  34
  35 /* IDA to assign each registered device a unique id */
  36 static DEFINE_IDA(iio_ida);
  37
  38 static dev_t iio_devt;
  39
  40 #define IIO_DEV_MAX 256
  41 struct bus_type iio_bus_type = {
  42         .name = "iio",
  43 };
  44 EXPORT_SYMBOL(iio_bus_type);
  45
  46 static struct dentry *iio_debugfs_dentry;
  47
  48 static const char * const iio_direction[] = {
  49         [0] = "in",
  50         [1] = "out",
  51 };
  52
  53 static const char * const iio_chan_type_name_spec[] = {
  54         [IIO_VOLTAGE] = "voltage",
  55         [IIO_CURRENT] = "current",
  56         [IIO_POWER] = "power",
  57         [IIO_ACCEL] = "accel",
  58         [IIO_ANGL_VEL] = "anglvel",
  59         [IIO_MAGN] = "magn",
  60         [IIO_LIGHT] = "illuminance",
  61         [IIO_INTENSITY] = "intensity",
  62         [IIO_PROXIMITY] = "proximity",
  63         [IIO_TEMP] = "temp",
  64         [IIO_INCLI] = "incli",
  65         [IIO_ROT] = "rot",
  66         [IIO_ANGL] = "angl",
  67         [IIO_TIMESTAMP] = "timestamp",
  68         [IIO_CAPACITANCE] = "capacitance",
  69         [IIO_ALTVOLTAGE] = "altvoltage",
  70         [IIO_CCT] = "cct",
  71         [IIO_PRESSURE] = "pressure",
  72         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  73 };
  74
  75 static const char * const iio_modifier_names[] = {
  76         [IIO_MOD_X] = "x",
  77         [IIO_MOD_Y] = "y",
  78         [IIO_MOD_Z] = "z",
  79         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
  80         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
  81         [IIO_MOD_LIGHT_BOTH] = "both",
  82         [IIO_MOD_LIGHT_IR] = "ir",
  83         [IIO_MOD_LIGHT_CLEAR] = "clear",
  84         [IIO_MOD_LIGHT_RED] = "red",
  85         [IIO_MOD_LIGHT_GREEN] = "green",
  86         [IIO_MOD_LIGHT_BLUE] = "blue",
  87 };
  88
  89 /* relies on pairs of these shared then separate */
  90 static const char * const iio_chan_info_postfix[] = {
  91         [IIO_CHAN_INFO_RAW] = "raw",
  92         [IIO_CHAN_INFO_PROCESSED] = "input",
  93         [IIO_CHAN_INFO_SCALE] = "scale",
  94         [IIO_CHAN_INFO_OFFSET] = "offset",
  95         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
  96         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
  97         [IIO_CHAN_INFO_PEAK] = "peak_raw",
  98         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
  99         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 100         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 101         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 102         = "filter_low_pass_3db_frequency",
 103         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 104         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 105         [IIO_CHAN_INFO_PHASE] = "phase",
 106         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 107         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 108         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 109 };
 110
 111 /**
 112  * iio_find_channel_from_si() - get channel from its scan index
 113  * @indio_dev:          device
 114  * @si:                 scan index to match
 115  */
 116 const struct iio_chan_spec
 117 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 118 {
 119         int i;
 120
 121         for (i = 0; i < indio_dev->num_channels; i++)
 122                 if (indio_dev->channels[i].scan_index == si)
 123                         return &indio_dev->channels[i];
 124         return NULL;
 125 }
 126
 127 /* This turns up an awful lot */
 128 ssize_t iio_read_const_attr(struct device *dev,
 129                             struct device_attribute *attr,
 130                             char *buf)
 131 {
 132         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 133 }
 134 EXPORT_SYMBOL(iio_read_const_attr);
 135
 136 static int __init iio_init(void)
 137 {
 138         int ret;
 139
 140         /* Register sysfs bus */
 141         ret  = bus_register(&iio_bus_type);
 142         if (ret < 0) {
 143                 pr_err("could not register bus type\n");
 144                 goto error_nothing;
 145         }
 146
 147         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 148         if (ret < 0) {
 149                 pr_err("failed to allocate char dev region\n");
 150                 goto error_unregister_bus_type;
 151         }
 152
 153         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 154
 155         return 0;
 156
 157 error_unregister_bus_type:
 158         bus_unregister(&iio_bus_type);
 159 error_nothing:
 160         return ret;
 161 }
 162
 163 static void __exit iio_exit(void)
 164 {
 165         if (iio_devt)
 166                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 167         bus_unregister(&iio_bus_type);
 168         debugfs_remove(iio_debugfs_dentry);
 169 }
 170
 171 #if defined(CONFIG_DEBUG_FS)
 172 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 173                               size_t count, loff_t *ppos)
 174 {
 175         struct iio_dev *indio_dev = file->private_data;
 176         char buf[20];
 177         unsigned val = 0;
 178         ssize_t len;
 179         int ret;
 180
 181         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 182                                                   indio_dev->cached_reg_addr,
 183                                                   0, &val);
 184         if (ret)
 185                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 186
 187         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 188
 189         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 190 }
 191
 192 static ssize_t iio_debugfs_write_reg(struct file *file,
 193                      const char __user *userbuf, size_t count, loff_t *ppos)
 194 {
 195         struct iio_dev *indio_dev = file->private_data;
 196         unsigned reg, val;
 197         char buf[80];
 198         int ret;
 199
 200         count = min_t(size_t, count, (sizeof(buf)-1));
 201         if (copy_from_user(buf, userbuf, count))
 202                 return -EFAULT;
 203
 204         buf[count] = 0;
 205
 206         ret = sscanf(buf, "%i %i", &reg, &val);
 207
 208         switch (ret) {
 209         case 1:
 210                 indio_dev->cached_reg_addr = reg;
 211                 break;
 212         case 2:
 213                 indio_dev->cached_reg_addr = reg;
 214                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 215                                                           val, NULL);
 216                 if (ret) {
 217                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 218                                 __func__);
 219                         return ret;
 220                 }
 221                 break;
 222         default:
 223                 return -EINVAL;
 224         }
 225
 226         return count;
 227 }
 228
 229 static const struct file_operations iio_debugfs_reg_fops = {
 230         .open = simple_open,
 231         .read = iio_debugfs_read_reg,
 232         .write = iio_debugfs_write_reg,
 233 };
 234
 235 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 236 {
 237         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 238 }
 239
 240 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 241 {
 242         struct dentry *d;
 243
 244         if (indio_dev->info->debugfs_reg_access == NULL)
 245                 return 0;
 246
 247         if (!iio_debugfs_dentry)
 248                 return 0;
 249
 250         indio_dev->debugfs_dentry =
 251                 debugfs_create_dir(dev_name(&indio_dev->dev),
 252                                    iio_debugfs_dentry);
 253         if (indio_dev->debugfs_dentry == NULL) {
 254                 dev_warn(indio_dev->dev.parent,
 255                          "Failed to create debugfs directory\n");
 256                 return -EFAULT;
 257         }
 258
 259         d = debugfs_create_file("direct_reg_access", 0644,
 260                                 indio_dev->debugfs_dentry,
 261                                 indio_dev, &iio_debugfs_reg_fops);
 262         if (!d) {
 263                 iio_device_unregister_debugfs(indio_dev);
 264                 return -ENOMEM;
 265         }
 266
 267         return 0;
 268 }
 269 #else
 270 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 271 {
 272         return 0;
 273 }
 274
 275 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 276 {
 277 }
 278 #endif /* CONFIG_DEBUG_FS */
 279
 280 static ssize_t iio_read_channel_ext_info(struct device *dev,
 281                                      struct device_attribute *attr,
 282                                      char *buf)
 283 {
 284         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 285         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 286         const struct iio_chan_spec_ext_info *ext_info;
 287
 288         ext_info = &this_attr->c->ext_info[this_attr->address];
 289
 290         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 291 }
 292
 293 static ssize_t iio_write_channel_ext_info(struct device *dev,
 294                                      struct device_attribute *attr,
 295                                      const char *buf,
 296                                          size_t len)
 297 {
 298         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 299         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 300         const struct iio_chan_spec_ext_info *ext_info;
 301
 302         ext_info = &this_attr->c->ext_info[this_attr->address];
 303
 304         return ext_info->write(indio_dev, ext_info->private,
 305                                this_attr->c, buf, len);
 306 }
 307
 308 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 309         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 310 {
 311         const struct iio_enum *e = (const struct iio_enum *)priv;
 312         unsigned int i;
 313         size_t len = 0;
 314
 315         if (!e->num_items)
 316                 return 0;
 317
 318         for (i = 0; i < e->num_items; ++i)
 319                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 320
 321         /* replace last space with a newline */
 322         buf[len - 1] = '\n';
 323
 324         return len;
 325 }
 326 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 327
 328 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 329         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 330 {
 331         const struct iio_enum *e = (const struct iio_enum *)priv;
 332         int i;
 333
 334         if (!e->get)
 335                 return -EINVAL;
 336
 337         i = e->get(indio_dev, chan);
 338         if (i < 0)
 339                 return i;
 340         else if (i >= e->num_items)
 341                 return -EINVAL;
 342
 343         return sprintf(buf, "%s\n", e->items[i]);
 344 }
 345 EXPORT_SYMBOL_GPL(iio_enum_read);
 346
 347 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 348         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 349         size_t len)
 350 {
 351         const struct iio_enum *e = (const struct iio_enum *)priv;
 352         unsigned int i;
 353         int ret;
 354
 355         if (!e->set)
 356                 return -EINVAL;
 357
 358         for (i = 0; i < e->num_items; i++) {
 359                 if (sysfs_streq(buf, e->items[i]))
 360                         break;
 361         }
 362
 363         if (i == e->num_items)
 364                 return -EINVAL;
 365
 366         ret = e->set(indio_dev, chan, i);
 367         return ret ? ret : len;
 368 }
 369 EXPORT_SYMBOL_GPL(iio_enum_write);
 370
 371 /**
 372  * iio_format_value() - Formats a IIO value into its string representation
 373  * @buf: The buffer to which the formated value gets written
 374  * @type: One of the IIO_VAL_... constants. This decides how the val and val2
 375  *        parameters are formatted.
 376  * @val: First part of the value, exact meaning depends on the type parameter.
 377  * @val2: Second part of the value, exact meaning depends on the type parameter.
 378  */
 379 ssize_t iio_format_value(char *buf, unsigned int type, int val, int val2)
 380 {
 381         unsigned long long tmp;
 382         bool scale_db = false;
 383
 384         switch (type) {
 385         case IIO_VAL_INT:
 386                 return sprintf(buf, "%d\n", val);
 387         case IIO_VAL_INT_PLUS_MICRO_DB:
 388                 scale_db = true;
 389         case IIO_VAL_INT_PLUS_MICRO:
 390                 if (val2 < 0)
 391                         return sprintf(buf, "-%ld.%06u%s\n", abs(val), -val2,
 392                                 scale_db ? " dB" : "");
 393                 else
 394                         return sprintf(buf, "%d.%06u%s\n", val, val2,
 395                                 scale_db ? " dB" : "");
 396         case IIO_VAL_INT_PLUS_NANO:
 397                 if (val2 < 0)
 398                         return sprintf(buf, "-%ld.%09u\n", abs(val), -val2);
 399                 else
 400                         return sprintf(buf, "%d.%09u\n", val, val2);
 401         case IIO_VAL_FRACTIONAL:
 402                 tmp = div_s64((s64)val * 1000000000LL, val2);
 403                 val2 = do_div(tmp, 1000000000LL);
 404                 val = tmp;
 405                 return sprintf(buf, "%d.%09u\n", val, val2);
 406         case IIO_VAL_FRACTIONAL_LOG2:
 407                 tmp = (s64)val * 1000000000LL >> val2;
 408                 val2 = do_div(tmp, 1000000000LL);
 409                 val = tmp;
 410                 return sprintf(buf, "%d.%09u\n", val, val2);
 411         default:
 412                 return 0;
 413         }
 414 }
 415
 416 static ssize_t iio_read_channel_info(struct device *dev,
 417                                      struct device_attribute *attr,
 418                                      char *buf)
 419 {
 420         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 421         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 422         int val, val2;
 423         int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 424                                             &val, &val2, this_attr->address);
 425
 426         if (ret < 0)
 427                 return ret;
 428
 429         return iio_format_value(buf, ret, val, val2);
 430 }
 431
 432 /**
 433  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 434  * @str: The string to parse
 435  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 436  * @integer: The integer part of the number
 437  * @fract: The fractional part of the number
 438  *
 439  * Returns 0 on success, or a negative error code if the string could not be
 440  * parsed.
 441  */
 442 int iio_str_to_fixpoint(const char *str, int fract_mult,
 443         int *integer, int *fract)
 444 {
 445         int i = 0, f = 0;
 446         bool integer_part = true, negative = false;
 447
 448         if (str[0] == '-') {
 449                 negative = true;
 450                 str++;
 451         } else if (str[0] == '+') {
 452                 str++;
 453         }
 454
 455         while (*str) {
 456                 if ('0' <= *str && *str <= '9') {
 457                         if (integer_part) {
 458                                 i = i * 10 + *str - '0';
 459                         } else {
 460                                 f += fract_mult * (*str - '0');
 461                                 fract_mult /= 10;
 462                         }
 463                 } else if (*str == '\n') {
 464                         if (*(str + 1) == '\0')
 465                                 break;
 466                         else
 467                                 return -EINVAL;
 468                 } else if (*str == '.' && integer_part) {
 469                         integer_part = false;
 470                 } else {
 471                         return -EINVAL;
 472                 }
 473                 str++;
 474         }
 475
 476         if (negative) {
 477                 if (i)
 478                         i = -i;
 479                 else
 480                         f = -f;
 481         }
 482
 483         *integer = i;
 484         *fract = f;
 485
 486         return 0;
 487 }
 488 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 489
 490 static ssize_t iio_write_channel_info(struct device *dev,
 491                                       struct device_attribute *attr,
 492                                       const char *buf,
 493                                       size_t len)
 494 {
 495         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 496         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 497         int ret, fract_mult = 100000;
 498         int integer, fract;
 499
 500         /* Assumes decimal - precision based on number of digits */
 501         if (!indio_dev->info->write_raw)
 502                 return -EINVAL;
 503
 504         if (indio_dev->info->write_raw_get_fmt)
 505                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 506                         this_attr->c, this_attr->address)) {
 507                 case IIO_VAL_INT_PLUS_MICRO:
 508                         fract_mult = 100000;
 509                         break;
 510                 case IIO_VAL_INT_PLUS_NANO:
 511                         fract_mult = 100000000;
 512                         break;
 513                 default:
 514                         return -EINVAL;
 515                 }
 516
 517         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 518         if (ret)
 519                 return ret;
 520
 521         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 522                                          integer, fract, this_attr->address);
 523         if (ret)
 524                 return ret;
 525
 526         return len;
 527 }
 528
 529 static
 530 int __iio_device_attr_init(struct device_attribute *dev_attr,
 531                            const char *postfix,
 532                            struct iio_chan_spec const *chan,
 533                            ssize_t (*readfunc)(struct device *dev,
 534                                                struct device_attribute *attr,
 535                                                char *buf),
 536                            ssize_t (*writefunc)(struct device *dev,
 537                                                 struct device_attribute *attr,
 538                                                 const char *buf,
 539                                                 size_t len),
 540                            enum iio_shared_by shared_by)
 541 {
 542         int ret = 0;
 543         char *name = NULL;
 544         char *full_postfix;
 545         sysfs_attr_init(&dev_attr->attr);
 546
 547         /* Build up postfix of <extend_name>_<modifier>_postfix */
 548         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 549                 if (chan->extend_name)
 550                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 551                                                  iio_modifier_names[chan
 552                                                                     ->channel2],
 553                                                  chan->extend_name,
 554                                                  postfix);
 555                 else
 556                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 557                                                  iio_modifier_names[chan
 558                                                                     ->channel2],
 559                                                  postfix);
 560         } else {
 561                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 562                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 563                 else
 564                         full_postfix = kasprintf(GFP_KERNEL,
 565                                                  "%s_%s",
 566                                                  chan->extend_name,
 567                                                  postfix);
 568         }
 569         if (full_postfix == NULL)
 570                 return -ENOMEM;
 571
 572         if (chan->differential) { /* Differential can not have modifier */
 573                 switch (shared_by) {
 574                 case IIO_SHARED_BY_ALL:
 575                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 576                         break;
 577                 case IIO_SHARED_BY_DIR:
 578                         name = kasprintf(GFP_KERNEL, "%s_%s",
 579                                                 iio_direction[chan->output],
 580                                                 full_postfix);
 581                         break;
 582                 case IIO_SHARED_BY_TYPE:
 583                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 584                                             iio_direction[chan->output],
 585                                             iio_chan_type_name_spec[chan->type],
 586                                             iio_chan_type_name_spec[chan->type],
 587                                             full_postfix);
 588                         break;
 589                 case IIO_SEPARATE:
 590                         if (!chan->indexed) {
 591                                 WARN_ON("Differential channels must be indexed\n");
 592                                 ret = -EINVAL;
 593                                 goto error_free_full_postfix;
 594                         }
 595                         name = kasprintf(GFP_KERNEL,
 596                                             "%s_%s%d-%s%d_%s",
 597                                             iio_direction[chan->output],
 598                                             iio_chan_type_name_spec[chan->type],
 599                                             chan->channel,
 600                                             iio_chan_type_name_spec[chan->type],
 601                                             chan->channel2,
 602                                             full_postfix);
 603                         break;
 604                 }
 605         } else { /* Single ended */
 606                 switch (shared_by) {
 607                 case IIO_SHARED_BY_ALL:
 608                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 609                         break;
 610                 case IIO_SHARED_BY_DIR:
 611                         name = kasprintf(GFP_KERNEL, "%s_%s",
 612                                                 iio_direction[chan->output],
 613                                                 full_postfix);
 614                         break;
 615                 case IIO_SHARED_BY_TYPE:
 616                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 617                                             iio_direction[chan->output],
 618                                             iio_chan_type_name_spec[chan->type],
 619                                             full_postfix);
 620                         break;
 621
 622                 case IIO_SEPARATE:
 623                         if (chan->indexed)
 624                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 625                                                     iio_direction[chan->output],
 626                                                     iio_chan_type_name_spec[chan->type],
 627                                                     chan->channel,
 628                                                     full_postfix);
 629                         else
 630                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 631                                                     iio_direction[chan->output],
 632                                                     iio_chan_type_name_spec[chan->type],
 633                                                     full_postfix);
 634                         break;
 635                 }
 636         }
 637         if (name == NULL) {
 638                 ret = -ENOMEM;
 639                 goto error_free_full_postfix;
 640         }
 641         dev_attr->attr.name = name;
 642
 643         if (readfunc) {
 644                 dev_attr->attr.mode |= S_IRUGO;
 645                 dev_attr->show = readfunc;
 646         }
 647
 648         if (writefunc) {
 649                 dev_attr->attr.mode |= S_IWUSR;
 650                 dev_attr->store = writefunc;
 651         }
 652
 653 error_free_full_postfix:
 654         kfree(full_postfix);
 655
 656         return ret;
 657 }
 658
 659 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 660 {
 661         kfree(dev_attr->attr.name);
 662 }
 663
 664 int __iio_add_chan_devattr(const char *postfix,
 665                            struct iio_chan_spec const *chan,
 666                            ssize_t (*readfunc)(struct device *dev,
 667                                                struct device_attribute *attr,
 668                                                char *buf),
 669                            ssize_t (*writefunc)(struct device *dev,
 670                                                 struct device_attribute *attr,
 671                                                 const char *buf,
 672                                                 size_t len),
 673                            u64 mask,
 674                            enum iio_shared_by shared_by,
 675                            struct device *dev,
 676                            struct list_head *attr_list)
 677 {
 678         int ret;
 679         struct iio_dev_attr *iio_attr, *t;
 680
 681         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
 682         if (iio_attr == NULL)
 683                 return -ENOMEM;
 684         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 685                                      postfix, chan,
 686                                      readfunc, writefunc, shared_by);
 687         if (ret)
 688                 goto error_iio_dev_attr_free;
 689         iio_attr->c = chan;
 690         iio_attr->address = mask;
 691         list_for_each_entry(t, attr_list, l)
 692                 if (strcmp(t->dev_attr.attr.name,
 693                            iio_attr->dev_attr.attr.name) == 0) {
 694                         if (shared_by == IIO_SEPARATE)
 695                                 dev_err(dev, "tried to double register : %s\n",
 696                                         t->dev_attr.attr.name);
 697                         ret = -EBUSY;
 698                         goto error_device_attr_deinit;
 699                 }
 700         list_add(&iio_attr->l, attr_list);
 701
 702         return 0;
 703
 704 error_device_attr_deinit:
 705         __iio_device_attr_deinit(&iio_attr->dev_attr);
 706 error_iio_dev_attr_free:
 707         kfree(iio_attr);
 708         return ret;
 709 }
 710
 711 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
 712                                          struct iio_chan_spec const *chan,
 713                                          enum iio_shared_by shared_by,
 714                                          const long *infomask)
 715 {
 716         int i, ret, attrcount = 0;
 717
 718         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
 719                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
 720                                              chan,
 721                                              &iio_read_channel_info,
 722                                              &iio_write_channel_info,
 723                                              i,
 724                                              shared_by,
 725                                              &indio_dev->dev,
 726                                              &indio_dev->channel_attr_list);
 727                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
 728                         continue;
 729                 else if (ret < 0)
 730                         return ret;
 731                 attrcount++;
 732         }
 733
 734         return attrcount;
 735 }
 736
 737 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 738                                         struct iio_chan_spec const *chan)
 739 {
 740         int ret, attrcount = 0;
 741         const struct iio_chan_spec_ext_info *ext_info;
 742
 743         if (chan->channel < 0)
 744                 return 0;
 745         ret = iio_device_add_info_mask_type(indio_dev, chan,
 746                                             IIO_SEPARATE,
 747                                             &chan->info_mask_separate);
 748         if (ret < 0)
 749                 return ret;
 750         attrcount += ret;
 751
 752         ret = iio_device_add_info_mask_type(indio_dev, chan,
 753                                             IIO_SHARED_BY_TYPE,
 754                                             &chan->info_mask_shared_by_type);
 755         if (ret < 0)
 756                 return ret;
 757         attrcount += ret;
 758
 759         ret = iio_device_add_info_mask_type(indio_dev, chan,
 760                                             IIO_SHARED_BY_DIR,
 761                                             &chan->info_mask_shared_by_dir);
 762         if (ret < 0)
 763                 return ret;
 764         attrcount += ret;
 765
 766         ret = iio_device_add_info_mask_type(indio_dev, chan,
 767                                             IIO_SHARED_BY_ALL,
 768                                             &chan->info_mask_shared_by_all);
 769         if (ret < 0)
 770                 return ret;
 771         attrcount += ret;
 772
 773         if (chan->ext_info) {
 774                 unsigned int i = 0;
 775                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 776                         ret = __iio_add_chan_devattr(ext_info->name,
 777                                         chan,
 778                                         ext_info->read ?
 779                                             &iio_read_channel_ext_info : NULL,
 780                                         ext_info->write ?
 781                                             &iio_write_channel_ext_info : NULL,
 782                                         i,
 783                                         ext_info->shared,
 784                                         &indio_dev->dev,
 785                                         &indio_dev->channel_attr_list);
 786                         i++;
 787                         if (ret == -EBUSY && ext_info->shared)
 788                                 continue;
 789
 790                         if (ret)
 791                                 return ret;
 792
 793                         attrcount++;
 794                 }
 795         }
 796
 797         return attrcount;
 798 }
 799
 800 /**
 801  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
 802  * @attr_list: List of IIO device attributes
 803  *
 804  * This function frees the memory allocated for each of the IIO device
 805  * attributes in the list. Note: if you want to reuse the list after calling
 806  * this function you have to reinitialize it using INIT_LIST_HEAD().
 807  */
 808 void iio_free_chan_devattr_list(struct list_head *attr_list)
 809 {
 810         struct iio_dev_attr *p, *n;
 811
 812         list_for_each_entry_safe(p, n, attr_list, l) {
 813                 kfree(p->dev_attr.attr.name);
 814                 kfree(p);
 815         }
 816 }
 817
 818 static ssize_t iio_show_dev_name(struct device *dev,
 819                                  struct device_attribute *attr,
 820                                  char *buf)
 821 {
 822         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 823         return sprintf(buf, "%s\n", indio_dev->name);
 824 }
 825
 826 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 827
 828 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 829 {
 830         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 831         struct iio_dev_attr *p;
 832         struct attribute **attr;
 833
 834         /* First count elements in any existing group */
 835         if (indio_dev->info->attrs) {
 836                 attr = indio_dev->info->attrs->attrs;
 837                 while (*attr++ != NULL)
 838                         attrcount_orig++;
 839         }
 840         attrcount = attrcount_orig;
 841         /*
 842          * New channel registration method - relies on the fact a group does
 843          * not need to be initialized if its name is NULL.
 844          */
 845         if (indio_dev->channels)
 846                 for (i = 0; i < indio_dev->num_channels; i++) {
 847                         ret = iio_device_add_channel_sysfs(indio_dev,
 848                                                            &indio_dev
 849                                                            ->channels[i]);
 850                         if (ret < 0)
 851                                 goto error_clear_attrs;
 852                         attrcount += ret;
 853                 }
 854
 855         if (indio_dev->name)
 856                 attrcount++;
 857
 858         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 859                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 860                                                    GFP_KERNEL);
 861         if (indio_dev->chan_attr_group.attrs == NULL) {
 862                 ret = -ENOMEM;
 863                 goto error_clear_attrs;
 864         }
 865         /* Copy across original attributes */
 866         if (indio_dev->info->attrs)
 867                 memcpy(indio_dev->chan_attr_group.attrs,
 868                        indio_dev->info->attrs->attrs,
 869                        sizeof(indio_dev->chan_attr_group.attrs[0])
 870                        *attrcount_orig);
 871         attrn = attrcount_orig;
 872         /* Add all elements from the list. */
 873         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 874                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 875         if (indio_dev->name)
 876                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 877
 878         indio_dev->groups[indio_dev->groupcounter++] =
 879                 &indio_dev->chan_attr_group;
 880
 881         return 0;
 882
 883 error_clear_attrs:
 884         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 885
 886         return ret;
 887 }
 888
 889 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 890 {
 891
 892         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 893         kfree(indio_dev->chan_attr_group.attrs);
 894 }
 895
 896 static void iio_dev_release(struct device *device)
 897 {
 898         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 899         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 900                 iio_device_unregister_trigger_consumer(indio_dev);
 901         iio_device_unregister_eventset(indio_dev);
 902         iio_device_unregister_sysfs(indio_dev);
 903
 904         iio_buffer_put(indio_dev->buffer);
 905
 906         ida_simple_remove(&iio_ida, indio_dev->id);
 907         kfree(indio_dev);
 908 }
 909
 910 struct device_type iio_device_type = {
 911         .name = "iio_device",
 912         .release = iio_dev_release,
 913 };
 914
 915 /**
 916  * iio_device_alloc() - allocate an iio_dev from a driver
 917  * @sizeof_priv:        Space to allocate for private structure.
 918  **/
 919 struct iio_dev *iio_device_alloc(int sizeof_priv)
 920 {
 921         struct iio_dev *dev;
 922         size_t alloc_size;
 923
 924         alloc_size = sizeof(struct iio_dev);
 925         if (sizeof_priv) {
 926                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 927                 alloc_size += sizeof_priv;
 928         }
 929         /* ensure 32-byte alignment of whole construct ? */
 930         alloc_size += IIO_ALIGN - 1;
 931
 932         dev = kzalloc(alloc_size, GFP_KERNEL);
 933
 934         if (dev) {
 935                 dev->dev.groups = dev->groups;
 936                 dev->dev.type = &iio_device_type;
 937                 dev->dev.bus = &iio_bus_type;
 938                 device_initialize(&dev->dev);
 939                 dev_set_drvdata(&dev->dev, (void *)dev);
 940                 mutex_init(&dev->mlock);
 941                 mutex_init(&dev->info_exist_lock);
 942                 INIT_LIST_HEAD(&dev->channel_attr_list);
 943
 944                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 945                 if (dev->id < 0) {
 946                         /* cannot use a dev_err as the name isn't available */
 947                         pr_err("failed to get device id\n");
 948                         kfree(dev);
 949                         return NULL;
 950                 }
 951                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 952                 INIT_LIST_HEAD(&dev->buffer_list);
 953         }
 954
 955         return dev;
 956 }
 957 EXPORT_SYMBOL(iio_device_alloc);
 958
 959 /**
 960  * iio_device_free() - free an iio_dev from a driver
 961  * @dev:                the iio_dev associated with the device
 962  **/
 963 void iio_device_free(struct iio_dev *dev)
 964 {
 965         if (dev)
 966                 put_device(&dev->dev);
 967 }
 968 EXPORT_SYMBOL(iio_device_free);
 969
 970 static void devm_iio_device_release(struct device *dev, void *res)
 971 {
 972         iio_device_free(*(struct iio_dev **)res);
 973 }
 974
 975 static int devm_iio_device_match(struct device *dev, void *res, void *data)
 976 {
 977         struct iio_dev **r = res;
 978         if (!r || !*r) {
 979                 WARN_ON(!r || !*r);
 980                 return 0;
 981         }
 982         return *r == data;
 983 }
 984
 985 /**
 986  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
 987  * @dev:                Device to allocate iio_dev for
 988  * @sizeof_priv:        Space to allocate for private structure.
 989  *
 990  * Managed iio_device_alloc. iio_dev allocated with this function is
 991  * automatically freed on driver detach.
 992  *
 993  * If an iio_dev allocated with this function needs to be freed separately,
 994  * devm_iio_device_free() must be used.
 995  *
 996  * RETURNS:
 997  * Pointer to allocated iio_dev on success, NULL on failure.
 998  */
 999 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1000 {
1001         struct iio_dev **ptr, *iio_dev;
1002
1003         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1004                            GFP_KERNEL);
1005         if (!ptr)
1006                 return NULL;
1007
1008         /* use raw alloc_dr for kmalloc caller tracing */
1009         iio_dev = iio_device_alloc(sizeof_priv);
1010         if (iio_dev) {
1011                 *ptr = iio_dev;
1012                 devres_add(dev, ptr);
1013         } else {
1014                 devres_free(ptr);
1015         }
1016
1017         return iio_dev;
1018 }
1019 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1020
1021 /**
1022  * devm_iio_device_free - Resource-managed iio_device_free()
1023  * @dev:                Device this iio_dev belongs to
1024  * @iio_dev:            the iio_dev associated with the device
1025  *
1026  * Free iio_dev allocated with devm_iio_device_alloc().
1027  */
1028 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1029 {
1030         int rc;
1031
1032         rc = devres_release(dev, devm_iio_device_release,
1033                             devm_iio_device_match, iio_dev);
1034         WARN_ON(rc);
1035 }
1036 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1037
1038 /**
1039  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1040  **/
1041 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1042 {
1043         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1044                                                 struct iio_dev, chrdev);
1045
1046         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1047                 return -EBUSY;
1048
1049         iio_device_get(indio_dev);
1050
1051         filp->private_data = indio_dev;
1052
1053         return 0;
1054 }
1055
1056 /**
1057  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1058  **/
1059 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1060 {
1061         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1062                                                 struct iio_dev, chrdev);
1063         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1064         iio_device_put(indio_dev);
1065
1066         return 0;
1067 }
1068
1069 /* Somewhat of a cross file organization violation - ioctls here are actually
1070  * event related */
1071 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1072 {
1073         struct iio_dev *indio_dev = filp->private_data;
1074         int __user *ip = (int __user *)arg;
1075         int fd;
1076
1077         if (!indio_dev->info)
1078                 return -ENODEV;
1079
1080         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1081                 fd = iio_event_getfd(indio_dev);
1082                 if (copy_to_user(ip, &fd, sizeof(fd)))
1083                         return -EFAULT;
1084                 return 0;
1085         }
1086         return -EINVAL;
1087 }
1088
1089 static const struct file_operations iio_buffer_fileops = {
1090         .read = iio_buffer_read_first_n_outer_addr,
1091         .release = iio_chrdev_release,
1092         .open = iio_chrdev_open,
1093         .poll = iio_buffer_poll_addr,
1094         .owner = THIS_MODULE,
1095         .llseek = noop_llseek,
1096         .unlocked_ioctl = iio_ioctl,
1097         .compat_ioctl = iio_ioctl,
1098 };
1099
1100 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1101
1102 /**
1103  * iio_device_register() - register a device with the IIO subsystem
1104  * @indio_dev:          Device structure filled by the device driver
1105  **/
1106 int iio_device_register(struct iio_dev *indio_dev)
1107 {
1108         int ret;
1109
1110         /* If the calling driver did not initialize of_node, do it here */
1111         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1112                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1113
1114         /* configure elements for the chrdev */
1115         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1116
1117         ret = iio_device_register_debugfs(indio_dev);
1118         if (ret) {
1119                 dev_err(indio_dev->dev.parent,
1120                         "Failed to register debugfs interfaces\n");
1121                 return ret;
1122         }
1123         ret = iio_device_register_sysfs(indio_dev);
1124         if (ret) {
1125                 dev_err(indio_dev->dev.parent,
1126                         "Failed to register sysfs interfaces\n");
1127                 goto error_unreg_debugfs;
1128         }
1129         ret = iio_device_register_eventset(indio_dev);
1130         if (ret) {
1131                 dev_err(indio_dev->dev.parent,
1132                         "Failed to register event set\n");
1133                 goto error_free_sysfs;
1134         }
1135         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
1136                 iio_device_register_trigger_consumer(indio_dev);
1137
1138         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1139                 indio_dev->setup_ops == NULL)
1140                 indio_dev->setup_ops = &noop_ring_setup_ops;
1141
1142         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1143         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1144         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1145         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1146         if (ret < 0)
1147                 goto error_unreg_eventset;
1148
1149         ret = device_add(&indio_dev->dev);
1150         if (ret < 0)
1151                 goto error_cdev_del;
1152
1153         return 0;
1154 error_cdev_del:
1155         cdev_del(&indio_dev->chrdev);
1156 error_unreg_eventset:
1157         iio_device_unregister_eventset(indio_dev);
1158 error_free_sysfs:
1159         iio_device_unregister_sysfs(indio_dev);
1160 error_unreg_debugfs:
1161         iio_device_unregister_debugfs(indio_dev);
1162         return ret;
1163 }
1164 EXPORT_SYMBOL(iio_device_register);
1165
1166 /**
1167  * iio_device_unregister() - unregister a device from the IIO subsystem
1168  * @indio_dev:          Device structure representing the device.
1169  **/
1170 void iio_device_unregister(struct iio_dev *indio_dev)
1171 {
1172         mutex_lock(&indio_dev->info_exist_lock);
1173
1174         device_del(&indio_dev->dev);
1175
1176         if (indio_dev->chrdev.dev)
1177                 cdev_del(&indio_dev->chrdev);
1178         iio_device_unregister_debugfs(indio_dev);
1179
1180         iio_disable_all_buffers(indio_dev);
1181
1182         indio_dev->info = NULL;
1183
1184         iio_device_wakeup_eventset(indio_dev);
1185         iio_buffer_wakeup_poll(indio_dev);
1186
1187         mutex_unlock(&indio_dev->info_exist_lock);
1188 }
1189 EXPORT_SYMBOL(iio_device_unregister);
1190
1191 static void devm_iio_device_unreg(struct device *dev, void *res)
1192 {
1193         iio_device_unregister(*(struct iio_dev **)res);
1194 }
1195
1196 /**
1197  * devm_iio_device_register - Resource-managed iio_device_register()
1198  * @dev:        Device to allocate iio_dev for
1199  * @indio_dev:  Device structure filled by the device driver
1200  *
1201  * Managed iio_device_register.  The IIO device registered with this
1202  * function is automatically unregistered on driver detach. This function
1203  * calls iio_device_register() internally. Refer to that function for more
1204  * information.
1205  *
1206  * If an iio_dev registered with this function needs to be unregistered
1207  * separately, devm_iio_device_unregister() must be used.
1208  *
1209  * RETURNS:
1210  * 0 on success, negative error number on failure.
1211  */
1212 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1213 {
1214         struct iio_dev **ptr;
1215         int ret;
1216
1217         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1218         if (!ptr)
1219                 return -ENOMEM;
1220
1221         *ptr = indio_dev;
1222         ret = iio_device_register(indio_dev);
1223         if (!ret)
1224                 devres_add(dev, ptr);
1225         else
1226                 devres_free(ptr);
1227
1228         return ret;
1229 }
1230 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1231
1232 /**
1233  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1234  * @dev:        Device this iio_dev belongs to
1235  * @indio_dev:  the iio_dev associated with the device
1236  *
1237  * Unregister iio_dev registered with devm_iio_device_register().
1238  */
1239 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1240 {
1241         int rc;
1242
1243         rc = devres_release(dev, devm_iio_device_unreg,
1244                             devm_iio_device_match, indio_dev);
1245         WARN_ON(rc);
1246 }
1247 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1248
1249 subsys_initcall(iio_init);
1250 module_exit(iio_exit);
1251
1252 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1253 MODULE_DESCRIPTION("Industrial I/O core");
1254 MODULE_LICENSE("GPL");