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_format = 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_format = kasprintf(GFP_KERNEL, "%s", full_postfix);
 576                         break;
 577                 case IIO_SHARED_BY_DIR:
 578                         name_format = kasprintf(GFP_KERNEL, "%s_%s",
 579                                                 iio_direction[chan->output],
 580                                                 full_postfix);
 581                         break;
 582                 case IIO_SHARED_BY_TYPE:
 583                         name_format
 584                                 = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 585                                             iio_direction[chan->output],
 586                                             iio_chan_type_name_spec[chan->type],
 587                                             iio_chan_type_name_spec[chan->type],
 588                                             full_postfix);
 589                         break;
 590                 case IIO_SEPARATE:
 591                         if (!chan->indexed) {
 592                                 WARN_ON("Differential channels must be indexed\n");
 593                                 ret = -EINVAL;
 594                                 goto error_free_full_postfix;
 595                         }
 596                         name_format
 597                                 = kasprintf(GFP_KERNEL,
 598                                             "%s_%s%d-%s%d_%s",
 599                                             iio_direction[chan->output],
 600                                             iio_chan_type_name_spec[chan->type],
 601                                             chan->channel,
 602                                             iio_chan_type_name_spec[chan->type],
 603                                             chan->channel2,
 604                                             full_postfix);
 605                         break;
 606                 }
 607         } else { /* Single ended */
 608                 switch (shared_by) {
 609                 case IIO_SHARED_BY_ALL:
 610                         name_format = kasprintf(GFP_KERNEL, "%s", full_postfix);
 611                         break;
 612                 case IIO_SHARED_BY_DIR:
 613                         name_format = kasprintf(GFP_KERNEL, "%s_%s",
 614                                                 iio_direction[chan->output],
 615                                                 full_postfix);
 616                         break;
 617                 case IIO_SHARED_BY_TYPE:
 618                         name_format
 619                                 = kasprintf(GFP_KERNEL, "%s_%s_%s",
 620                                             iio_direction[chan->output],
 621                                             iio_chan_type_name_spec[chan->type],
 622                                             full_postfix);
 623                         break;
 624
 625                 case IIO_SEPARATE:
 626                         if (chan->indexed)
 627                                 name_format
 628                                         = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 629                                                     iio_direction[chan->output],
 630                                                     iio_chan_type_name_spec[chan->type],
 631                                                     chan->channel,
 632                                                     full_postfix);
 633                         else
 634                                 name_format
 635                                         = kasprintf(GFP_KERNEL, "%s_%s_%s",
 636                                                     iio_direction[chan->output],
 637                                                     iio_chan_type_name_spec[chan->type],
 638                                                     full_postfix);
 639                         break;
 640                 }
 641         }
 642         if (name_format == NULL) {
 643                 ret = -ENOMEM;
 644                 goto error_free_full_postfix;
 645         }
 646         dev_attr->attr.name = kasprintf(GFP_KERNEL,
 647                                         name_format,
 648                                         chan->channel,
 649                                         chan->channel2);
 650         if (dev_attr->attr.name == NULL) {
 651                 ret = -ENOMEM;
 652                 goto error_free_name_format;
 653         }
 654
 655         if (readfunc) {
 656                 dev_attr->attr.mode |= S_IRUGO;
 657                 dev_attr->show = readfunc;
 658         }
 659
 660         if (writefunc) {
 661                 dev_attr->attr.mode |= S_IWUSR;
 662                 dev_attr->store = writefunc;
 663         }
 664 error_free_name_format:
 665         kfree(name_format);
 666 error_free_full_postfix:
 667         kfree(full_postfix);
 668
 669         return ret;
 670 }
 671
 672 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 673 {
 674         kfree(dev_attr->attr.name);
 675 }
 676
 677 int __iio_add_chan_devattr(const char *postfix,
 678                            struct iio_chan_spec const *chan,
 679                            ssize_t (*readfunc)(struct device *dev,
 680                                                struct device_attribute *attr,
 681                                                char *buf),
 682                            ssize_t (*writefunc)(struct device *dev,
 683                                                 struct device_attribute *attr,
 684                                                 const char *buf,
 685                                                 size_t len),
 686                            u64 mask,
 687                            enum iio_shared_by shared_by,
 688                            struct device *dev,
 689                            struct list_head *attr_list)
 690 {
 691         int ret;
 692         struct iio_dev_attr *iio_attr, *t;
 693
 694         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
 695         if (iio_attr == NULL)
 696                 return -ENOMEM;
 697         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 698                                      postfix, chan,
 699                                      readfunc, writefunc, shared_by);
 700         if (ret)
 701                 goto error_iio_dev_attr_free;
 702         iio_attr->c = chan;
 703         iio_attr->address = mask;
 704         list_for_each_entry(t, attr_list, l)
 705                 if (strcmp(t->dev_attr.attr.name,
 706                            iio_attr->dev_attr.attr.name) == 0) {
 707                         if (shared_by == IIO_SEPARATE)
 708                                 dev_err(dev, "tried to double register : %s\n",
 709                                         t->dev_attr.attr.name);
 710                         ret = -EBUSY;
 711                         goto error_device_attr_deinit;
 712                 }
 713         list_add(&iio_attr->l, attr_list);
 714
 715         return 0;
 716
 717 error_device_attr_deinit:
 718         __iio_device_attr_deinit(&iio_attr->dev_attr);
 719 error_iio_dev_attr_free:
 720         kfree(iio_attr);
 721         return ret;
 722 }
 723
 724 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
 725                                          struct iio_chan_spec const *chan,
 726                                          enum iio_shared_by shared_by,
 727                                          const long *infomask)
 728 {
 729         int i, ret, attrcount = 0;
 730
 731         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
 732                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
 733                                              chan,
 734                                              &iio_read_channel_info,
 735                                              &iio_write_channel_info,
 736                                              i,
 737                                              shared_by,
 738                                              &indio_dev->dev,
 739                                              &indio_dev->channel_attr_list);
 740                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
 741                         continue;
 742                 else if (ret < 0)
 743                         return ret;
 744                 attrcount++;
 745         }
 746
 747         return attrcount;
 748 }
 749
 750 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 751                                         struct iio_chan_spec const *chan)
 752 {
 753         int ret, attrcount = 0;
 754         const struct iio_chan_spec_ext_info *ext_info;
 755
 756         if (chan->channel < 0)
 757                 return 0;
 758         ret = iio_device_add_info_mask_type(indio_dev, chan,
 759                                             IIO_SEPARATE,
 760                                             &chan->info_mask_separate);
 761         if (ret < 0)
 762                 return ret;
 763         attrcount += ret;
 764
 765         ret = iio_device_add_info_mask_type(indio_dev, chan,
 766                                             IIO_SHARED_BY_TYPE,
 767                                             &chan->info_mask_shared_by_type);
 768         if (ret < 0)
 769                 return ret;
 770         attrcount += ret;
 771
 772         ret = iio_device_add_info_mask_type(indio_dev, chan,
 773                                             IIO_SHARED_BY_DIR,
 774                                             &chan->info_mask_shared_by_dir);
 775         if (ret < 0)
 776                 return ret;
 777         attrcount += ret;
 778
 779         ret = iio_device_add_info_mask_type(indio_dev, chan,
 780                                             IIO_SHARED_BY_ALL,
 781                                             &chan->info_mask_shared_by_all);
 782         if (ret < 0)
 783                 return ret;
 784         attrcount += ret;
 785
 786         if (chan->ext_info) {
 787                 unsigned int i = 0;
 788                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 789                         ret = __iio_add_chan_devattr(ext_info->name,
 790                                         chan,
 791                                         ext_info->read ?
 792                                             &iio_read_channel_ext_info : NULL,
 793                                         ext_info->write ?
 794                                             &iio_write_channel_ext_info : NULL,
 795                                         i,
 796                                         ext_info->shared,
 797                                         &indio_dev->dev,
 798                                         &indio_dev->channel_attr_list);
 799                         i++;
 800                         if (ret == -EBUSY && ext_info->shared)
 801                                 continue;
 802
 803                         if (ret)
 804                                 return ret;
 805
 806                         attrcount++;
 807                 }
 808         }
 809
 810         return attrcount;
 811 }
 812
 813 /**
 814  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
 815  * @attr_list: List of IIO device attributes
 816  *
 817  * This function frees the memory allocated for each of the IIO device
 818  * attributes in the list. Note: if you want to reuse the list after calling
 819  * this function you have to reinitialize it using INIT_LIST_HEAD().
 820  */
 821 void iio_free_chan_devattr_list(struct list_head *attr_list)
 822 {
 823         struct iio_dev_attr *p, *n;
 824
 825         list_for_each_entry_safe(p, n, attr_list, l) {
 826                 kfree(p->dev_attr.attr.name);
 827                 kfree(p);
 828         }
 829 }
 830
 831 static ssize_t iio_show_dev_name(struct device *dev,
 832                                  struct device_attribute *attr,
 833                                  char *buf)
 834 {
 835         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 836         return sprintf(buf, "%s\n", indio_dev->name);
 837 }
 838
 839 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 840
 841 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 842 {
 843         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 844         struct iio_dev_attr *p;
 845         struct attribute **attr;
 846
 847         /* First count elements in any existing group */
 848         if (indio_dev->info->attrs) {
 849                 attr = indio_dev->info->attrs->attrs;
 850                 while (*attr++ != NULL)
 851                         attrcount_orig++;
 852         }
 853         attrcount = attrcount_orig;
 854         /*
 855          * New channel registration method - relies on the fact a group does
 856          * not need to be initialized if its name is NULL.
 857          */
 858         if (indio_dev->channels)
 859                 for (i = 0; i < indio_dev->num_channels; i++) {
 860                         ret = iio_device_add_channel_sysfs(indio_dev,
 861                                                            &indio_dev
 862                                                            ->channels[i]);
 863                         if (ret < 0)
 864                                 goto error_clear_attrs;
 865                         attrcount += ret;
 866                 }
 867
 868         if (indio_dev->name)
 869                 attrcount++;
 870
 871         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 872                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 873                                                    GFP_KERNEL);
 874         if (indio_dev->chan_attr_group.attrs == NULL) {
 875                 ret = -ENOMEM;
 876                 goto error_clear_attrs;
 877         }
 878         /* Copy across original attributes */
 879         if (indio_dev->info->attrs)
 880                 memcpy(indio_dev->chan_attr_group.attrs,
 881                        indio_dev->info->attrs->attrs,
 882                        sizeof(indio_dev->chan_attr_group.attrs[0])
 883                        *attrcount_orig);
 884         attrn = attrcount_orig;
 885         /* Add all elements from the list. */
 886         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 887                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 888         if (indio_dev->name)
 889                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 890
 891         indio_dev->groups[indio_dev->groupcounter++] =
 892                 &indio_dev->chan_attr_group;
 893
 894         return 0;
 895
 896 error_clear_attrs:
 897         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 898
 899         return ret;
 900 }
 901
 902 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 903 {
 904
 905         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 906         kfree(indio_dev->chan_attr_group.attrs);
 907 }
 908
 909 static void iio_dev_release(struct device *device)
 910 {
 911         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 912         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 913                 iio_device_unregister_trigger_consumer(indio_dev);
 914         iio_device_unregister_eventset(indio_dev);
 915         iio_device_unregister_sysfs(indio_dev);
 916
 917         iio_buffer_put(indio_dev->buffer);
 918
 919         ida_simple_remove(&iio_ida, indio_dev->id);
 920         kfree(indio_dev);
 921 }
 922
 923 struct device_type iio_device_type = {
 924         .name = "iio_device",
 925         .release = iio_dev_release,
 926 };
 927
 928 /**
 929  * iio_device_alloc() - allocate an iio_dev from a driver
 930  * @sizeof_priv:        Space to allocate for private structure.
 931  **/
 932 struct iio_dev *iio_device_alloc(int sizeof_priv)
 933 {
 934         struct iio_dev *dev;
 935         size_t alloc_size;
 936
 937         alloc_size = sizeof(struct iio_dev);
 938         if (sizeof_priv) {
 939                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 940                 alloc_size += sizeof_priv;
 941         }
 942         /* ensure 32-byte alignment of whole construct ? */
 943         alloc_size += IIO_ALIGN - 1;
 944
 945         dev = kzalloc(alloc_size, GFP_KERNEL);
 946
 947         if (dev) {
 948                 dev->dev.groups = dev->groups;
 949                 dev->dev.type = &iio_device_type;
 950                 dev->dev.bus = &iio_bus_type;
 951                 device_initialize(&dev->dev);
 952                 dev_set_drvdata(&dev->dev, (void *)dev);
 953                 mutex_init(&dev->mlock);
 954                 mutex_init(&dev->info_exist_lock);
 955                 INIT_LIST_HEAD(&dev->channel_attr_list);
 956
 957                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 958                 if (dev->id < 0) {
 959                         /* cannot use a dev_err as the name isn't available */
 960                         pr_err("failed to get device id\n");
 961                         kfree(dev);
 962                         return NULL;
 963                 }
 964                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 965                 INIT_LIST_HEAD(&dev->buffer_list);
 966         }
 967
 968         return dev;
 969 }
 970 EXPORT_SYMBOL(iio_device_alloc);
 971
 972 /**
 973  * iio_device_free() - free an iio_dev from a driver
 974  * @dev:                the iio_dev associated with the device
 975  **/
 976 void iio_device_free(struct iio_dev *dev)
 977 {
 978         if (dev)
 979                 put_device(&dev->dev);
 980 }
 981 EXPORT_SYMBOL(iio_device_free);
 982
 983 static void devm_iio_device_release(struct device *dev, void *res)
 984 {
 985         iio_device_free(*(struct iio_dev **)res);
 986 }
 987
 988 static int devm_iio_device_match(struct device *dev, void *res, void *data)
 989 {
 990         struct iio_dev **r = res;
 991         if (!r || !*r) {
 992                 WARN_ON(!r || !*r);
 993                 return 0;
 994         }
 995         return *r == data;
 996 }
 997
 998 /**
 999  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1000  * @dev:                Device to allocate iio_dev for
1001  * @sizeof_priv:        Space to allocate for private structure.
1002  *
1003  * Managed iio_device_alloc. iio_dev allocated with this function is
1004  * automatically freed on driver detach.
1005  *
1006  * If an iio_dev allocated with this function needs to be freed separately,
1007  * devm_iio_device_free() must be used.
1008  *
1009  * RETURNS:
1010  * Pointer to allocated iio_dev on success, NULL on failure.
1011  */
1012 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1013 {
1014         struct iio_dev **ptr, *iio_dev;
1015
1016         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1017                            GFP_KERNEL);
1018         if (!ptr)
1019                 return NULL;
1020
1021         /* use raw alloc_dr for kmalloc caller tracing */
1022         iio_dev = iio_device_alloc(sizeof_priv);
1023         if (iio_dev) {
1024                 *ptr = iio_dev;
1025                 devres_add(dev, ptr);
1026         } else {
1027                 devres_free(ptr);
1028         }
1029
1030         return iio_dev;
1031 }
1032 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1033
1034 /**
1035  * devm_iio_device_free - Resource-managed iio_device_free()
1036  * @dev:                Device this iio_dev belongs to
1037  * @iio_dev:            the iio_dev associated with the device
1038  *
1039  * Free iio_dev allocated with devm_iio_device_alloc().
1040  */
1041 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1042 {
1043         int rc;
1044
1045         rc = devres_release(dev, devm_iio_device_release,
1046                             devm_iio_device_match, iio_dev);
1047         WARN_ON(rc);
1048 }
1049 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1050
1051 /**
1052  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1053  **/
1054 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1055 {
1056         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1057                                                 struct iio_dev, chrdev);
1058
1059         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1060                 return -EBUSY;
1061
1062         iio_device_get(indio_dev);
1063
1064         filp->private_data = indio_dev;
1065
1066         return 0;
1067 }
1068
1069 /**
1070  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1071  **/
1072 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1073 {
1074         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1075                                                 struct iio_dev, chrdev);
1076         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1077         iio_device_put(indio_dev);
1078
1079         return 0;
1080 }
1081
1082 /* Somewhat of a cross file organization violation - ioctls here are actually
1083  * event related */
1084 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1085 {
1086         struct iio_dev *indio_dev = filp->private_data;
1087         int __user *ip = (int __user *)arg;
1088         int fd;
1089
1090         if (!indio_dev->info)
1091                 return -ENODEV;
1092
1093         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1094                 fd = iio_event_getfd(indio_dev);
1095                 if (copy_to_user(ip, &fd, sizeof(fd)))
1096                         return -EFAULT;
1097                 return 0;
1098         }
1099         return -EINVAL;
1100 }
1101
1102 static const struct file_operations iio_buffer_fileops = {
1103         .read = iio_buffer_read_first_n_outer_addr,
1104         .release = iio_chrdev_release,
1105         .open = iio_chrdev_open,
1106         .poll = iio_buffer_poll_addr,
1107         .owner = THIS_MODULE,
1108         .llseek = noop_llseek,
1109         .unlocked_ioctl = iio_ioctl,
1110         .compat_ioctl = iio_ioctl,
1111 };
1112
1113 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1114
1115 /**
1116  * iio_device_register() - register a device with the IIO subsystem
1117  * @indio_dev:          Device structure filled by the device driver
1118  **/
1119 int iio_device_register(struct iio_dev *indio_dev)
1120 {
1121         int ret;
1122
1123         /* If the calling driver did not initialize of_node, do it here */
1124         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1125                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1126
1127         /* configure elements for the chrdev */
1128         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1129
1130         ret = iio_device_register_debugfs(indio_dev);
1131         if (ret) {
1132                 dev_err(indio_dev->dev.parent,
1133                         "Failed to register debugfs interfaces\n");
1134                 return ret;
1135         }
1136         ret = iio_device_register_sysfs(indio_dev);
1137         if (ret) {
1138                 dev_err(indio_dev->dev.parent,
1139                         "Failed to register sysfs interfaces\n");
1140                 goto error_unreg_debugfs;
1141         }
1142         ret = iio_device_register_eventset(indio_dev);
1143         if (ret) {
1144                 dev_err(indio_dev->dev.parent,
1145                         "Failed to register event set\n");
1146                 goto error_free_sysfs;
1147         }
1148         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
1149                 iio_device_register_trigger_consumer(indio_dev);
1150
1151         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1152                 indio_dev->setup_ops == NULL)
1153                 indio_dev->setup_ops = &noop_ring_setup_ops;
1154
1155         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1156         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1157         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1158         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1159         if (ret < 0)
1160                 goto error_unreg_eventset;
1161
1162         ret = device_add(&indio_dev->dev);
1163         if (ret < 0)
1164                 goto error_cdev_del;
1165
1166         return 0;
1167 error_cdev_del:
1168         cdev_del(&indio_dev->chrdev);
1169 error_unreg_eventset:
1170         iio_device_unregister_eventset(indio_dev);
1171 error_free_sysfs:
1172         iio_device_unregister_sysfs(indio_dev);
1173 error_unreg_debugfs:
1174         iio_device_unregister_debugfs(indio_dev);
1175         return ret;
1176 }
1177 EXPORT_SYMBOL(iio_device_register);
1178
1179 /**
1180  * iio_device_unregister() - unregister a device from the IIO subsystem
1181  * @indio_dev:          Device structure representing the device.
1182  **/
1183 void iio_device_unregister(struct iio_dev *indio_dev)
1184 {
1185         mutex_lock(&indio_dev->info_exist_lock);
1186
1187         device_del(&indio_dev->dev);
1188
1189         if (indio_dev->chrdev.dev)
1190                 cdev_del(&indio_dev->chrdev);
1191         iio_device_unregister_debugfs(indio_dev);
1192
1193         iio_disable_all_buffers(indio_dev);
1194
1195         indio_dev->info = NULL;
1196
1197         iio_device_wakeup_eventset(indio_dev);
1198         iio_buffer_wakeup_poll(indio_dev);
1199
1200         mutex_unlock(&indio_dev->info_exist_lock);
1201 }
1202 EXPORT_SYMBOL(iio_device_unregister);
1203
1204 static void devm_iio_device_unreg(struct device *dev, void *res)
1205 {
1206         iio_device_unregister(*(struct iio_dev **)res);
1207 }
1208
1209 /**
1210  * devm_iio_device_register - Resource-managed iio_device_register()
1211  * @dev:        Device to allocate iio_dev for
1212  * @indio_dev:  Device structure filled by the device driver
1213  *
1214  * Managed iio_device_register.  The IIO device registered with this
1215  * function is automatically unregistered on driver detach. This function
1216  * calls iio_device_register() internally. Refer to that function for more
1217  * information.
1218  *
1219  * If an iio_dev registered with this function needs to be unregistered
1220  * separately, devm_iio_device_unregister() must be used.
1221  *
1222  * RETURNS:
1223  * 0 on success, negative error number on failure.
1224  */
1225 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1226 {
1227         struct iio_dev **ptr;
1228         int ret;
1229
1230         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1231         if (!ptr)
1232                 return -ENOMEM;
1233
1234         *ptr = indio_dev;
1235         ret = iio_device_register(indio_dev);
1236         if (!ret)
1237                 devres_add(dev, ptr);
1238         else
1239                 devres_free(ptr);
1240
1241         return ret;
1242 }
1243 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1244
1245 /**
1246  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1247  * @dev:        Device this iio_dev belongs to
1248  * @indio_dev:  the iio_dev associated with the device
1249  *
1250  * Unregister iio_dev registered with devm_iio_device_register().
1251  */
1252 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1253 {
1254         int rc;
1255
1256         rc = devres_release(dev, devm_iio_device_unreg,
1257                             devm_iio_device_match, indio_dev);
1258         WARN_ON(rc);
1259 }
1260 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1261
1262 subsys_initcall(iio_init);
1263 module_exit(iio_exit);
1264
1265 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1266 MODULE_DESCRIPTION("Industrial I/O core");
1267 MODULE_LICENSE("GPL");