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