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         [IIO_MOD_QUATERNION] = "quaternion",
  88         [IIO_MOD_TEMP_AMBIENT] = "ambient",
  89         [IIO_MOD_TEMP_OBJECT] = "object",
  90 };
  91
  92 /* relies on pairs of these shared then separate */
  93 static const char * const iio_chan_info_postfix[] = {
  94         [IIO_CHAN_INFO_RAW] = "raw",
  95         [IIO_CHAN_INFO_PROCESSED] = "input",
  96         [IIO_CHAN_INFO_SCALE] = "scale",
  97         [IIO_CHAN_INFO_OFFSET] = "offset",
  98         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
  99         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 100         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 101         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 102         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 103         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 104         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 105         = "filter_low_pass_3db_frequency",
 106         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 107         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 108         [IIO_CHAN_INFO_PHASE] = "phase",
 109         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 110         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 111         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 112 };
 113
 114 /**
 115  * iio_find_channel_from_si() - get channel from its scan index
 116  * @indio_dev:          device
 117  * @si:                 scan index to match
 118  */
 119 const struct iio_chan_spec
 120 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 121 {
 122         int i;
 123
 124         for (i = 0; i < indio_dev->num_channels; i++)
 125                 if (indio_dev->channels[i].scan_index == si)
 126                         return &indio_dev->channels[i];
 127         return NULL;
 128 }
 129
 130 /* This turns up an awful lot */
 131 ssize_t iio_read_const_attr(struct device *dev,
 132                             struct device_attribute *attr,
 133                             char *buf)
 134 {
 135         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 136 }
 137 EXPORT_SYMBOL(iio_read_const_attr);
 138
 139 static int __init iio_init(void)
 140 {
 141         int ret;
 142
 143         /* Register sysfs bus */
 144         ret  = bus_register(&iio_bus_type);
 145         if (ret < 0) {
 146                 pr_err("could not register bus type\n");
 147                 goto error_nothing;
 148         }
 149
 150         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 151         if (ret < 0) {
 152                 pr_err("failed to allocate char dev region\n");
 153                 goto error_unregister_bus_type;
 154         }
 155
 156         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 157
 158         return 0;
 159
 160 error_unregister_bus_type:
 161         bus_unregister(&iio_bus_type);
 162 error_nothing:
 163         return ret;
 164 }
 165
 166 static void __exit iio_exit(void)
 167 {
 168         if (iio_devt)
 169                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 170         bus_unregister(&iio_bus_type);
 171         debugfs_remove(iio_debugfs_dentry);
 172 }
 173
 174 #if defined(CONFIG_DEBUG_FS)
 175 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 176                               size_t count, loff_t *ppos)
 177 {
 178         struct iio_dev *indio_dev = file->private_data;
 179         char buf[20];
 180         unsigned val = 0;
 181         ssize_t len;
 182         int ret;
 183
 184         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 185                                                   indio_dev->cached_reg_addr,
 186                                                   0, &val);
 187         if (ret)
 188                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 189
 190         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 191
 192         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 193 }
 194
 195 static ssize_t iio_debugfs_write_reg(struct file *file,
 196                      const char __user *userbuf, size_t count, loff_t *ppos)
 197 {
 198         struct iio_dev *indio_dev = file->private_data;
 199         unsigned reg, val;
 200         char buf[80];
 201         int ret;
 202
 203         count = min_t(size_t, count, (sizeof(buf)-1));
 204         if (copy_from_user(buf, userbuf, count))
 205                 return -EFAULT;
 206
 207         buf[count] = 0;
 208
 209         ret = sscanf(buf, "%i %i", &reg, &val);
 210
 211         switch (ret) {
 212         case 1:
 213                 indio_dev->cached_reg_addr = reg;
 214                 break;
 215         case 2:
 216                 indio_dev->cached_reg_addr = reg;
 217                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 218                                                           val, NULL);
 219                 if (ret) {
 220                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 221                                 __func__);
 222                         return ret;
 223                 }
 224                 break;
 225         default:
 226                 return -EINVAL;
 227         }
 228
 229         return count;
 230 }
 231
 232 static const struct file_operations iio_debugfs_reg_fops = {
 233         .open = simple_open,
 234         .read = iio_debugfs_read_reg,
 235         .write = iio_debugfs_write_reg,
 236 };
 237
 238 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 239 {
 240         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 241 }
 242
 243 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 244 {
 245         struct dentry *d;
 246
 247         if (indio_dev->info->debugfs_reg_access == NULL)
 248                 return 0;
 249
 250         if (!iio_debugfs_dentry)
 251                 return 0;
 252
 253         indio_dev->debugfs_dentry =
 254                 debugfs_create_dir(dev_name(&indio_dev->dev),
 255                                    iio_debugfs_dentry);
 256         if (indio_dev->debugfs_dentry == NULL) {
 257                 dev_warn(indio_dev->dev.parent,
 258                          "Failed to create debugfs directory\n");
 259                 return -EFAULT;
 260         }
 261
 262         d = debugfs_create_file("direct_reg_access", 0644,
 263                                 indio_dev->debugfs_dentry,
 264                                 indio_dev, &iio_debugfs_reg_fops);
 265         if (!d) {
 266                 iio_device_unregister_debugfs(indio_dev);
 267                 return -ENOMEM;
 268         }
 269
 270         return 0;
 271 }
 272 #else
 273 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 274 {
 275         return 0;
 276 }
 277
 278 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 279 {
 280 }
 281 #endif /* CONFIG_DEBUG_FS */
 282
 283 static ssize_t iio_read_channel_ext_info(struct device *dev,
 284                                      struct device_attribute *attr,
 285                                      char *buf)
 286 {
 287         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 288         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 289         const struct iio_chan_spec_ext_info *ext_info;
 290
 291         ext_info = &this_attr->c->ext_info[this_attr->address];
 292
 293         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 294 }
 295
 296 static ssize_t iio_write_channel_ext_info(struct device *dev,
 297                                      struct device_attribute *attr,
 298                                      const char *buf,
 299                                          size_t len)
 300 {
 301         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 302         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 303         const struct iio_chan_spec_ext_info *ext_info;
 304
 305         ext_info = &this_attr->c->ext_info[this_attr->address];
 306
 307         return ext_info->write(indio_dev, ext_info->private,
 308                                this_attr->c, buf, len);
 309 }
 310
 311 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 312         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 313 {
 314         const struct iio_enum *e = (const struct iio_enum *)priv;
 315         unsigned int i;
 316         size_t len = 0;
 317
 318         if (!e->num_items)
 319                 return 0;
 320
 321         for (i = 0; i < e->num_items; ++i)
 322                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 323
 324         /* replace last space with a newline */
 325         buf[len - 1] = '\n';
 326
 327         return len;
 328 }
 329 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 330
 331 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 332         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 333 {
 334         const struct iio_enum *e = (const struct iio_enum *)priv;
 335         int i;
 336
 337         if (!e->get)
 338                 return -EINVAL;
 339
 340         i = e->get(indio_dev, chan);
 341         if (i < 0)
 342                 return i;
 343         else if (i >= e->num_items)
 344                 return -EINVAL;
 345
 346         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 347 }
 348 EXPORT_SYMBOL_GPL(iio_enum_read);
 349
 350 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 351         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 352         size_t len)
 353 {
 354         const struct iio_enum *e = (const struct iio_enum *)priv;
 355         unsigned int i;
 356         int ret;
 357
 358         if (!e->set)
 359                 return -EINVAL;
 360
 361         for (i = 0; i < e->num_items; i++) {
 362                 if (sysfs_streq(buf, e->items[i]))
 363                         break;
 364         }
 365
 366         if (i == e->num_items)
 367                 return -EINVAL;
 368
 369         ret = e->set(indio_dev, chan, i);
 370         return ret ? ret : len;
 371 }
 372 EXPORT_SYMBOL_GPL(iio_enum_write);
 373
 374 /**
 375  * iio_format_value() - Formats a IIO value into its string representation
 376  * @buf: The buffer to which the formated value gets written
 377  * @type: One of the IIO_VAL_... constants. This decides how the val and val2
 378  *        parameters are formatted.
 379  * @vals: pointer to the values, exact meaning depends on the type parameter.
 380  */
 381 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 382 {
 383         unsigned long long tmp;
 384         bool scale_db = false;
 385
 386         switch (type) {
 387         case IIO_VAL_INT:
 388                 return sprintf(buf, "%d\n", vals[0]);
 389         case IIO_VAL_INT_PLUS_MICRO_DB:
 390                 scale_db = true;
 391         case IIO_VAL_INT_PLUS_MICRO:
 392                 if (vals[1] < 0)
 393                         return sprintf(buf, "-%ld.%06u%s\n", abs(vals[0]),
 394                                         -vals[1],
 395                                 scale_db ? " dB" : "");
 396                 else
 397                         return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
 398                                 scale_db ? " dB" : "");
 399         case IIO_VAL_INT_PLUS_NANO:
 400                 if (vals[1] < 0)
 401                         return sprintf(buf, "-%ld.%09u\n", abs(vals[0]),
 402                                         -vals[1]);
 403                 else
 404                         return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 405         case IIO_VAL_FRACTIONAL:
 406                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 407                 vals[1] = do_div(tmp, 1000000000LL);
 408                 vals[0] = tmp;
 409                 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 410         case IIO_VAL_FRACTIONAL_LOG2:
 411                 tmp = (s64)vals[0] * 1000000000LL >> vals[1];
 412                 vals[1] = do_div(tmp, 1000000000LL);
 413                 vals[0] = tmp;
 414                 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 415         case IIO_VAL_INT_MULTIPLE:
 416         {
 417                 int i;
 418                 int len = 0;
 419
 420                 for (i = 0; i < size; ++i)
 421                         len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
 422                                                                 vals[i]);
 423                 len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
 424                 return len;
 425         }
 426         default:
 427                 return 0;
 428         }
 429 }
 430
 431 static ssize_t iio_read_channel_info(struct device *dev,
 432                                      struct device_attribute *attr,
 433                                      char *buf)
 434 {
 435         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 436         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 437         int vals[INDIO_MAX_RAW_ELEMENTS];
 438         int ret;
 439         int val_len = 2;
 440
 441         if (indio_dev->info->read_raw_multi)
 442                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 443                                                         INDIO_MAX_RAW_ELEMENTS,
 444                                                         vals, &val_len,
 445                                                         this_attr->address);
 446         else
 447                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 448                                     &vals[0], &vals[1], this_attr->address);
 449
 450         if (ret < 0)
 451                 return ret;
 452
 453         return iio_format_value(buf, ret, val_len, vals);
 454 }
 455
 456 /**
 457  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 458  * @str: The string to parse
 459  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 460  * @integer: The integer part of the number
 461  * @fract: The fractional part of the number
 462  *
 463  * Returns 0 on success, or a negative error code if the string could not be
 464  * parsed.
 465  */
 466 int iio_str_to_fixpoint(const char *str, int fract_mult,
 467         int *integer, int *fract)
 468 {
 469         int i = 0, f = 0;
 470         bool integer_part = true, negative = false;
 471
 472         if (str[0] == '-') {
 473                 negative = true;
 474                 str++;
 475         } else if (str[0] == '+') {
 476                 str++;
 477         }
 478
 479         while (*str) {
 480                 if ('0' <= *str && *str <= '9') {
 481                         if (integer_part) {
 482                                 i = i * 10 + *str - '0';
 483                         } else {
 484                                 f += fract_mult * (*str - '0');
 485                                 fract_mult /= 10;
 486                         }
 487                 } else if (*str == '\n') {
 488                         if (*(str + 1) == '\0')
 489                                 break;
 490                         else
 491                                 return -EINVAL;
 492                 } else if (*str == '.' && integer_part) {
 493                         integer_part = false;
 494                 } else {
 495                         return -EINVAL;
 496                 }
 497                 str++;
 498         }
 499
 500         if (negative) {
 501                 if (i)
 502                         i = -i;
 503                 else
 504                         f = -f;
 505         }
 506
 507         *integer = i;
 508         *fract = f;
 509
 510         return 0;
 511 }
 512 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 513
 514 static ssize_t iio_write_channel_info(struct device *dev,
 515                                       struct device_attribute *attr,
 516                                       const char *buf,
 517                                       size_t len)
 518 {
 519         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 520         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 521         int ret, fract_mult = 100000;
 522         int integer, fract;
 523
 524         /* Assumes decimal - precision based on number of digits */
 525         if (!indio_dev->info->write_raw)
 526                 return -EINVAL;
 527
 528         if (indio_dev->info->write_raw_get_fmt)
 529                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 530                         this_attr->c, this_attr->address)) {
 531                 case IIO_VAL_INT_PLUS_MICRO:
 532                         fract_mult = 100000;
 533                         break;
 534                 case IIO_VAL_INT_PLUS_NANO:
 535                         fract_mult = 100000000;
 536                         break;
 537                 default:
 538                         return -EINVAL;
 539                 }
 540
 541         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 542         if (ret)
 543                 return ret;
 544
 545         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 546                                          integer, fract, this_attr->address);
 547         if (ret)
 548                 return ret;
 549
 550         return len;
 551 }
 552
 553 static
 554 int __iio_device_attr_init(struct device_attribute *dev_attr,
 555                            const char *postfix,
 556                            struct iio_chan_spec const *chan,
 557                            ssize_t (*readfunc)(struct device *dev,
 558                                                struct device_attribute *attr,
 559                                                char *buf),
 560                            ssize_t (*writefunc)(struct device *dev,
 561                                                 struct device_attribute *attr,
 562                                                 const char *buf,
 563                                                 size_t len),
 564                            enum iio_shared_by shared_by)
 565 {
 566         int ret = 0;
 567         char *name = NULL;
 568         char *full_postfix;
 569         sysfs_attr_init(&dev_attr->attr);
 570
 571         /* Build up postfix of <extend_name>_<modifier>_postfix */
 572         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 573                 if (chan->extend_name)
 574                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 575                                                  iio_modifier_names[chan
 576                                                                     ->channel2],
 577                                                  chan->extend_name,
 578                                                  postfix);
 579                 else
 580                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 581                                                  iio_modifier_names[chan
 582                                                                     ->channel2],
 583                                                  postfix);
 584         } else {
 585                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 586                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 587                 else
 588                         full_postfix = kasprintf(GFP_KERNEL,
 589                                                  "%s_%s",
 590                                                  chan->extend_name,
 591                                                  postfix);
 592         }
 593         if (full_postfix == NULL)
 594                 return -ENOMEM;
 595
 596         if (chan->differential) { /* Differential can not have modifier */
 597                 switch (shared_by) {
 598                 case IIO_SHARED_BY_ALL:
 599                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 600                         break;
 601                 case IIO_SHARED_BY_DIR:
 602                         name = kasprintf(GFP_KERNEL, "%s_%s",
 603                                                 iio_direction[chan->output],
 604                                                 full_postfix);
 605                         break;
 606                 case IIO_SHARED_BY_TYPE:
 607                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 608                                             iio_direction[chan->output],
 609                                             iio_chan_type_name_spec[chan->type],
 610                                             iio_chan_type_name_spec[chan->type],
 611                                             full_postfix);
 612                         break;
 613                 case IIO_SEPARATE:
 614                         if (!chan->indexed) {
 615                                 WARN_ON("Differential channels must be indexed\n");
 616                                 ret = -EINVAL;
 617                                 goto error_free_full_postfix;
 618                         }
 619                         name = kasprintf(GFP_KERNEL,
 620                                             "%s_%s%d-%s%d_%s",
 621                                             iio_direction[chan->output],
 622                                             iio_chan_type_name_spec[chan->type],
 623                                             chan->channel,
 624                                             iio_chan_type_name_spec[chan->type],
 625                                             chan->channel2,
 626                                             full_postfix);
 627                         break;
 628                 }
 629         } else { /* Single ended */
 630                 switch (shared_by) {
 631                 case IIO_SHARED_BY_ALL:
 632                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 633                         break;
 634                 case IIO_SHARED_BY_DIR:
 635                         name = kasprintf(GFP_KERNEL, "%s_%s",
 636                                                 iio_direction[chan->output],
 637                                                 full_postfix);
 638                         break;
 639                 case IIO_SHARED_BY_TYPE:
 640                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 641                                             iio_direction[chan->output],
 642                                             iio_chan_type_name_spec[chan->type],
 643                                             full_postfix);
 644                         break;
 645
 646                 case IIO_SEPARATE:
 647                         if (chan->indexed)
 648                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 649                                                     iio_direction[chan->output],
 650                                                     iio_chan_type_name_spec[chan->type],
 651                                                     chan->channel,
 652                                                     full_postfix);
 653                         else
 654                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 655                                                     iio_direction[chan->output],
 656                                                     iio_chan_type_name_spec[chan->type],
 657                                                     full_postfix);
 658                         break;
 659                 }
 660         }
 661         if (name == NULL) {
 662                 ret = -ENOMEM;
 663                 goto error_free_full_postfix;
 664         }
 665         dev_attr->attr.name = name;
 666
 667         if (readfunc) {
 668                 dev_attr->attr.mode |= S_IRUGO;
 669                 dev_attr->show = readfunc;
 670         }
 671
 672         if (writefunc) {
 673                 dev_attr->attr.mode |= S_IWUSR;
 674                 dev_attr->store = writefunc;
 675         }
 676
 677 error_free_full_postfix:
 678         kfree(full_postfix);
 679
 680         return ret;
 681 }
 682
 683 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 684 {
 685         kfree(dev_attr->attr.name);
 686 }
 687
 688 int __iio_add_chan_devattr(const char *postfix,
 689                            struct iio_chan_spec const *chan,
 690                            ssize_t (*readfunc)(struct device *dev,
 691                                                struct device_attribute *attr,
 692                                                char *buf),
 693                            ssize_t (*writefunc)(struct device *dev,
 694                                                 struct device_attribute *attr,
 695                                                 const char *buf,
 696                                                 size_t len),
 697                            u64 mask,
 698                            enum iio_shared_by shared_by,
 699                            struct device *dev,
 700                            struct list_head *attr_list)
 701 {
 702         int ret;
 703         struct iio_dev_attr *iio_attr, *t;
 704
 705         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
 706         if (iio_attr == NULL)
 707                 return -ENOMEM;
 708         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 709                                      postfix, chan,
 710                                      readfunc, writefunc, shared_by);
 711         if (ret)
 712                 goto error_iio_dev_attr_free;
 713         iio_attr->c = chan;
 714         iio_attr->address = mask;
 715         list_for_each_entry(t, attr_list, l)
 716                 if (strcmp(t->dev_attr.attr.name,
 717                            iio_attr->dev_attr.attr.name) == 0) {
 718                         if (shared_by == IIO_SEPARATE)
 719                                 dev_err(dev, "tried to double register : %s\n",
 720                                         t->dev_attr.attr.name);
 721                         ret = -EBUSY;
 722                         goto error_device_attr_deinit;
 723                 }
 724         list_add(&iio_attr->l, attr_list);
 725
 726         return 0;
 727
 728 error_device_attr_deinit:
 729         __iio_device_attr_deinit(&iio_attr->dev_attr);
 730 error_iio_dev_attr_free:
 731         kfree(iio_attr);
 732         return ret;
 733 }
 734
 735 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
 736                                          struct iio_chan_spec const *chan,
 737                                          enum iio_shared_by shared_by,
 738                                          const long *infomask)
 739 {
 740         int i, ret, attrcount = 0;
 741
 742         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
 743                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
 744                         return -EINVAL;
 745                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
 746                                              chan,
 747                                              &iio_read_channel_info,
 748                                              &iio_write_channel_info,
 749                                              i,
 750                                              shared_by,
 751                                              &indio_dev->dev,
 752                                              &indio_dev->channel_attr_list);
 753                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
 754                         continue;
 755                 else if (ret < 0)
 756                         return ret;
 757                 attrcount++;
 758         }
 759
 760         return attrcount;
 761 }
 762
 763 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 764                                         struct iio_chan_spec const *chan)
 765 {
 766         int ret, attrcount = 0;
 767         const struct iio_chan_spec_ext_info *ext_info;
 768
 769         if (chan->channel < 0)
 770                 return 0;
 771         ret = iio_device_add_info_mask_type(indio_dev, chan,
 772                                             IIO_SEPARATE,
 773                                             &chan->info_mask_separate);
 774         if (ret < 0)
 775                 return ret;
 776         attrcount += ret;
 777
 778         ret = iio_device_add_info_mask_type(indio_dev, chan,
 779                                             IIO_SHARED_BY_TYPE,
 780                                             &chan->info_mask_shared_by_type);
 781         if (ret < 0)
 782                 return ret;
 783         attrcount += ret;
 784
 785         ret = iio_device_add_info_mask_type(indio_dev, chan,
 786                                             IIO_SHARED_BY_DIR,
 787                                             &chan->info_mask_shared_by_dir);
 788         if (ret < 0)
 789                 return ret;
 790         attrcount += ret;
 791
 792         ret = iio_device_add_info_mask_type(indio_dev, chan,
 793                                             IIO_SHARED_BY_ALL,
 794                                             &chan->info_mask_shared_by_all);
 795         if (ret < 0)
 796                 return ret;
 797         attrcount += ret;
 798
 799         if (chan->ext_info) {
 800                 unsigned int i = 0;
 801                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 802                         ret = __iio_add_chan_devattr(ext_info->name,
 803                                         chan,
 804                                         ext_info->read ?
 805                                             &iio_read_channel_ext_info : NULL,
 806                                         ext_info->write ?
 807                                             &iio_write_channel_ext_info : NULL,
 808                                         i,
 809                                         ext_info->shared,
 810                                         &indio_dev->dev,
 811                                         &indio_dev->channel_attr_list);
 812                         i++;
 813                         if (ret == -EBUSY && ext_info->shared)
 814                                 continue;
 815
 816                         if (ret)
 817                                 return ret;
 818
 819                         attrcount++;
 820                 }
 821         }
 822
 823         return attrcount;
 824 }
 825
 826 /**
 827  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
 828  * @attr_list: List of IIO device attributes
 829  *
 830  * This function frees the memory allocated for each of the IIO device
 831  * attributes in the list. Note: if you want to reuse the list after calling
 832  * this function you have to reinitialize it using INIT_LIST_HEAD().
 833  */
 834 void iio_free_chan_devattr_list(struct list_head *attr_list)
 835 {
 836         struct iio_dev_attr *p, *n;
 837
 838         list_for_each_entry_safe(p, n, attr_list, l) {
 839                 kfree(p->dev_attr.attr.name);
 840                 kfree(p);
 841         }
 842 }
 843
 844 static ssize_t iio_show_dev_name(struct device *dev,
 845                                  struct device_attribute *attr,
 846                                  char *buf)
 847 {
 848         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 849         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
 850 }
 851
 852 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 853
 854 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 855 {
 856         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 857         struct iio_dev_attr *p;
 858         struct attribute **attr;
 859
 860         /* First count elements in any existing group */
 861         if (indio_dev->info->attrs) {
 862                 attr = indio_dev->info->attrs->attrs;
 863                 while (*attr++ != NULL)
 864                         attrcount_orig++;
 865         }
 866         attrcount = attrcount_orig;
 867         /*
 868          * New channel registration method - relies on the fact a group does
 869          * not need to be initialized if its name is NULL.
 870          */
 871         if (indio_dev->channels)
 872                 for (i = 0; i < indio_dev->num_channels; i++) {
 873                         ret = iio_device_add_channel_sysfs(indio_dev,
 874                                                            &indio_dev
 875                                                            ->channels[i]);
 876                         if (ret < 0)
 877                                 goto error_clear_attrs;
 878                         attrcount += ret;
 879                 }
 880
 881         if (indio_dev->name)
 882                 attrcount++;
 883
 884         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 885                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 886                                                    GFP_KERNEL);
 887         if (indio_dev->chan_attr_group.attrs == NULL) {
 888                 ret = -ENOMEM;
 889                 goto error_clear_attrs;
 890         }
 891         /* Copy across original attributes */
 892         if (indio_dev->info->attrs)
 893                 memcpy(indio_dev->chan_attr_group.attrs,
 894                        indio_dev->info->attrs->attrs,
 895                        sizeof(indio_dev->chan_attr_group.attrs[0])
 896                        *attrcount_orig);
 897         attrn = attrcount_orig;
 898         /* Add all elements from the list. */
 899         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 900                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 901         if (indio_dev->name)
 902                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 903
 904         indio_dev->groups[indio_dev->groupcounter++] =
 905                 &indio_dev->chan_attr_group;
 906
 907         return 0;
 908
 909 error_clear_attrs:
 910         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 911
 912         return ret;
 913 }
 914
 915 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 916 {
 917
 918         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 919         kfree(indio_dev->chan_attr_group.attrs);
 920 }
 921
 922 static void iio_dev_release(struct device *device)
 923 {
 924         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 925         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 926                 iio_device_unregister_trigger_consumer(indio_dev);
 927         iio_device_unregister_eventset(indio_dev);
 928         iio_device_unregister_sysfs(indio_dev);
 929
 930         iio_buffer_put(indio_dev->buffer);
 931
 932         ida_simple_remove(&iio_ida, indio_dev->id);
 933         kfree(indio_dev);
 934 }
 935
 936 struct device_type iio_device_type = {
 937         .name = "iio_device",
 938         .release = iio_dev_release,
 939 };
 940
 941 /**
 942  * iio_device_alloc() - allocate an iio_dev from a driver
 943  * @sizeof_priv:        Space to allocate for private structure.
 944  **/
 945 struct iio_dev *iio_device_alloc(int sizeof_priv)
 946 {
 947         struct iio_dev *dev;
 948         size_t alloc_size;
 949
 950         alloc_size = sizeof(struct iio_dev);
 951         if (sizeof_priv) {
 952                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 953                 alloc_size += sizeof_priv;
 954         }
 955         /* ensure 32-byte alignment of whole construct ? */
 956         alloc_size += IIO_ALIGN - 1;
 957
 958         dev = kzalloc(alloc_size, GFP_KERNEL);
 959
 960         if (dev) {
 961                 dev->dev.groups = dev->groups;
 962                 dev->dev.type = &iio_device_type;
 963                 dev->dev.bus = &iio_bus_type;
 964                 device_initialize(&dev->dev);
 965                 dev_set_drvdata(&dev->dev, (void *)dev);
 966                 mutex_init(&dev->mlock);
 967                 mutex_init(&dev->info_exist_lock);
 968                 INIT_LIST_HEAD(&dev->channel_attr_list);
 969
 970                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 971                 if (dev->id < 0) {
 972                         /* cannot use a dev_err as the name isn't available */
 973                         pr_err("failed to get device id\n");
 974                         kfree(dev);
 975                         return NULL;
 976                 }
 977                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 978                 INIT_LIST_HEAD(&dev->buffer_list);
 979         }
 980
 981         return dev;
 982 }
 983 EXPORT_SYMBOL(iio_device_alloc);
 984
 985 /**
 986  * iio_device_free() - free an iio_dev from a driver
 987  * @dev:                the iio_dev associated with the device
 988  **/
 989 void iio_device_free(struct iio_dev *dev)
 990 {
 991         if (dev)
 992                 put_device(&dev->dev);
 993 }
 994 EXPORT_SYMBOL(iio_device_free);
 995
 996 static void devm_iio_device_release(struct device *dev, void *res)
 997 {
 998         iio_device_free(*(struct iio_dev **)res);
 999 }
1000
1001 static int devm_iio_device_match(struct device *dev, void *res, void *data)
1002 {
1003         struct iio_dev **r = res;
1004         if (!r || !*r) {
1005                 WARN_ON(!r || !*r);
1006                 return 0;
1007         }
1008         return *r == data;
1009 }
1010
1011 /**
1012  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1013  * @dev:                Device to allocate iio_dev for
1014  * @sizeof_priv:        Space to allocate for private structure.
1015  *
1016  * Managed iio_device_alloc. iio_dev allocated with this function is
1017  * automatically freed on driver detach.
1018  *
1019  * If an iio_dev allocated with this function needs to be freed separately,
1020  * devm_iio_device_free() must be used.
1021  *
1022  * RETURNS:
1023  * Pointer to allocated iio_dev on success, NULL on failure.
1024  */
1025 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1026 {
1027         struct iio_dev **ptr, *iio_dev;
1028
1029         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1030                            GFP_KERNEL);
1031         if (!ptr)
1032                 return NULL;
1033
1034         /* use raw alloc_dr for kmalloc caller tracing */
1035         iio_dev = iio_device_alloc(sizeof_priv);
1036         if (iio_dev) {
1037                 *ptr = iio_dev;
1038                 devres_add(dev, ptr);
1039         } else {
1040                 devres_free(ptr);
1041         }
1042
1043         return iio_dev;
1044 }
1045 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1046
1047 /**
1048  * devm_iio_device_free - Resource-managed iio_device_free()
1049  * @dev:                Device this iio_dev belongs to
1050  * @iio_dev:            the iio_dev associated with the device
1051  *
1052  * Free iio_dev allocated with devm_iio_device_alloc().
1053  */
1054 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1055 {
1056         int rc;
1057
1058         rc = devres_release(dev, devm_iio_device_release,
1059                             devm_iio_device_match, iio_dev);
1060         WARN_ON(rc);
1061 }
1062 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1063
1064 /**
1065  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1066  **/
1067 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1068 {
1069         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1070                                                 struct iio_dev, chrdev);
1071
1072         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1073                 return -EBUSY;
1074
1075         iio_device_get(indio_dev);
1076
1077         filp->private_data = indio_dev;
1078
1079         return 0;
1080 }
1081
1082 /**
1083  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1084  **/
1085 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1086 {
1087         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1088                                                 struct iio_dev, chrdev);
1089         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1090         iio_device_put(indio_dev);
1091
1092         return 0;
1093 }
1094
1095 /* Somewhat of a cross file organization violation - ioctls here are actually
1096  * event related */
1097 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1098 {
1099         struct iio_dev *indio_dev = filp->private_data;
1100         int __user *ip = (int __user *)arg;
1101         int fd;
1102
1103         if (!indio_dev->info)
1104                 return -ENODEV;
1105
1106         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1107                 fd = iio_event_getfd(indio_dev);
1108                 if (copy_to_user(ip, &fd, sizeof(fd)))
1109                         return -EFAULT;
1110                 return 0;
1111         }
1112         return -EINVAL;
1113 }
1114
1115 static const struct file_operations iio_buffer_fileops = {
1116         .read = iio_buffer_read_first_n_outer_addr,
1117         .release = iio_chrdev_release,
1118         .open = iio_chrdev_open,
1119         .poll = iio_buffer_poll_addr,
1120         .owner = THIS_MODULE,
1121         .llseek = noop_llseek,
1122         .unlocked_ioctl = iio_ioctl,
1123         .compat_ioctl = iio_ioctl,
1124 };
1125
1126 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1127
1128 /**
1129  * iio_device_register() - register a device with the IIO subsystem
1130  * @indio_dev:          Device structure filled by the device driver
1131  **/
1132 int iio_device_register(struct iio_dev *indio_dev)
1133 {
1134         int ret;
1135
1136         /* If the calling driver did not initialize of_node, do it here */
1137         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1138                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1139
1140         /* configure elements for the chrdev */
1141         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1142
1143         ret = iio_device_register_debugfs(indio_dev);
1144         if (ret) {
1145                 dev_err(indio_dev->dev.parent,
1146                         "Failed to register debugfs interfaces\n");
1147                 return ret;
1148         }
1149         ret = iio_device_register_sysfs(indio_dev);
1150         if (ret) {
1151                 dev_err(indio_dev->dev.parent,
1152                         "Failed to register sysfs interfaces\n");
1153                 goto error_unreg_debugfs;
1154         }
1155         ret = iio_device_register_eventset(indio_dev);
1156         if (ret) {
1157                 dev_err(indio_dev->dev.parent,
1158                         "Failed to register event set\n");
1159                 goto error_free_sysfs;
1160         }
1161         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
1162                 iio_device_register_trigger_consumer(indio_dev);
1163
1164         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1165                 indio_dev->setup_ops == NULL)
1166                 indio_dev->setup_ops = &noop_ring_setup_ops;
1167
1168         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1169         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1170         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1171         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1172         if (ret < 0)
1173                 goto error_unreg_eventset;
1174
1175         ret = device_add(&indio_dev->dev);
1176         if (ret < 0)
1177                 goto error_cdev_del;
1178
1179         return 0;
1180 error_cdev_del:
1181         cdev_del(&indio_dev->chrdev);
1182 error_unreg_eventset:
1183         iio_device_unregister_eventset(indio_dev);
1184 error_free_sysfs:
1185         iio_device_unregister_sysfs(indio_dev);
1186 error_unreg_debugfs:
1187         iio_device_unregister_debugfs(indio_dev);
1188         return ret;
1189 }
1190 EXPORT_SYMBOL(iio_device_register);
1191
1192 /**
1193  * iio_device_unregister() - unregister a device from the IIO subsystem
1194  * @indio_dev:          Device structure representing the device.
1195  **/
1196 void iio_device_unregister(struct iio_dev *indio_dev)
1197 {
1198         mutex_lock(&indio_dev->info_exist_lock);
1199
1200         device_del(&indio_dev->dev);
1201
1202         if (indio_dev->chrdev.dev)
1203                 cdev_del(&indio_dev->chrdev);
1204         iio_device_unregister_debugfs(indio_dev);
1205
1206         iio_disable_all_buffers(indio_dev);
1207
1208         indio_dev->info = NULL;
1209
1210         iio_device_wakeup_eventset(indio_dev);
1211         iio_buffer_wakeup_poll(indio_dev);
1212
1213         mutex_unlock(&indio_dev->info_exist_lock);
1214 }
1215 EXPORT_SYMBOL(iio_device_unregister);
1216
1217 static void devm_iio_device_unreg(struct device *dev, void *res)
1218 {
1219         iio_device_unregister(*(struct iio_dev **)res);
1220 }
1221
1222 /**
1223  * devm_iio_device_register - Resource-managed iio_device_register()
1224  * @dev:        Device to allocate iio_dev for
1225  * @indio_dev:  Device structure filled by the device driver
1226  *
1227  * Managed iio_device_register.  The IIO device registered with this
1228  * function is automatically unregistered on driver detach. This function
1229  * calls iio_device_register() internally. Refer to that function for more
1230  * information.
1231  *
1232  * If an iio_dev registered with this function needs to be unregistered
1233  * separately, devm_iio_device_unregister() must be used.
1234  *
1235  * RETURNS:
1236  * 0 on success, negative error number on failure.
1237  */
1238 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1239 {
1240         struct iio_dev **ptr;
1241         int ret;
1242
1243         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1244         if (!ptr)
1245                 return -ENOMEM;
1246
1247         *ptr = indio_dev;
1248         ret = iio_device_register(indio_dev);
1249         if (!ret)
1250                 devres_add(dev, ptr);
1251         else
1252                 devres_free(ptr);
1253
1254         return ret;
1255 }
1256 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1257
1258 /**
1259  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1260  * @dev:        Device this iio_dev belongs to
1261  * @indio_dev:  the iio_dev associated with the device
1262  *
1263  * Unregister iio_dev registered with devm_iio_device_register().
1264  */
1265 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1266 {
1267         int rc;
1268
1269         rc = devres_release(dev, devm_iio_device_unreg,
1270                             devm_iio_device_match, indio_dev);
1271         WARN_ON(rc);
1272 }
1273 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1274
1275 subsys_initcall(iio_init);
1276 module_exit(iio_exit);
1277
1278 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1279 MODULE_DESCRIPTION("Industrial I/O core");
1280 MODULE_LICENSE("GPL");