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 snprintf(buf, PAGE_SIZE, "%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  * @vals: pointer to the values, exact meaning depends on the type parameter.
 377  */
 378 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 379 {
 380         unsigned long long tmp;
 381         bool scale_db = false;
 382
 383         switch (type) {
 384         case IIO_VAL_INT:
 385                 return sprintf(buf, "%d\n", vals[0]);
 386         case IIO_VAL_INT_PLUS_MICRO_DB:
 387                 scale_db = true;
 388         case IIO_VAL_INT_PLUS_MICRO:
 389                 if (vals[1] < 0)
 390                         return sprintf(buf, "-%ld.%06u%s\n", abs(vals[0]),
 391                                         -vals[1],
 392                                 scale_db ? " dB" : "");
 393                 else
 394                         return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
 395                                 scale_db ? " dB" : "");
 396         case IIO_VAL_INT_PLUS_NANO:
 397                 if (vals[1] < 0)
 398                         return sprintf(buf, "-%ld.%09u\n", abs(vals[0]),
 399                                         -vals[1]);
 400                 else
 401                         return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 402         case IIO_VAL_FRACTIONAL:
 403                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 404                 vals[1] = do_div(tmp, 1000000000LL);
 405                 vals[0] = tmp;
 406                 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 407         case IIO_VAL_FRACTIONAL_LOG2:
 408                 tmp = (s64)vals[0] * 1000000000LL >> vals[1];
 409                 vals[1] = do_div(tmp, 1000000000LL);
 410                 vals[0] = tmp;
 411                 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 412         case IIO_VAL_INT_MULTIPLE:
 413         {
 414                 int i;
 415                 int len = 0;
 416
 417                 for (i = 0; i < size; ++i)
 418                         len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
 419                                                                 vals[i]);
 420                 len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
 421                 return len;
 422         }
 423         default:
 424                 return 0;
 425         }
 426 }
 427
 428 static ssize_t iio_read_channel_info(struct device *dev,
 429                                      struct device_attribute *attr,
 430                                      char *buf)
 431 {
 432         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 433         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 434         int vals[INDIO_MAX_RAW_ELEMENTS];
 435         int ret;
 436         int val_len = 2;
 437
 438         if (indio_dev->info->read_raw_multi)
 439                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 440                                                         INDIO_MAX_RAW_ELEMENTS,
 441                                                         vals, &val_len,
 442                                                         this_attr->address);
 443         else
 444                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 445                                     &vals[0], &vals[1], this_attr->address);
 446
 447         if (ret < 0)
 448                 return ret;
 449
 450         return iio_format_value(buf, ret, val_len, vals);
 451 }
 452
 453 /**
 454  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 455  * @str: The string to parse
 456  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 457  * @integer: The integer part of the number
 458  * @fract: The fractional part of the number
 459  *
 460  * Returns 0 on success, or a negative error code if the string could not be
 461  * parsed.
 462  */
 463 int iio_str_to_fixpoint(const char *str, int fract_mult,
 464         int *integer, int *fract)
 465 {
 466         int i = 0, f = 0;
 467         bool integer_part = true, negative = false;
 468
 469         if (str[0] == '-') {
 470                 negative = true;
 471                 str++;
 472         } else if (str[0] == '+') {
 473                 str++;
 474         }
 475
 476         while (*str) {
 477                 if ('0' <= *str && *str <= '9') {
 478                         if (integer_part) {
 479                                 i = i * 10 + *str - '0';
 480                         } else {
 481                                 f += fract_mult * (*str - '0');
 482                                 fract_mult /= 10;
 483                         }
 484                 } else if (*str == '\n') {
 485                         if (*(str + 1) == '\0')
 486                                 break;
 487                         else
 488                                 return -EINVAL;
 489                 } else if (*str == '.' && integer_part) {
 490                         integer_part = false;
 491                 } else {
 492                         return -EINVAL;
 493                 }
 494                 str++;
 495         }
 496
 497         if (negative) {
 498                 if (i)
 499                         i = -i;
 500                 else
 501                         f = -f;
 502         }
 503
 504         *integer = i;
 505         *fract = f;
 506
 507         return 0;
 508 }
 509 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 510
 511 static ssize_t iio_write_channel_info(struct device *dev,
 512                                       struct device_attribute *attr,
 513                                       const char *buf,
 514                                       size_t len)
 515 {
 516         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 517         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 518         int ret, fract_mult = 100000;
 519         int integer, fract;
 520
 521         /* Assumes decimal - precision based on number of digits */
 522         if (!indio_dev->info->write_raw)
 523                 return -EINVAL;
 524
 525         if (indio_dev->info->write_raw_get_fmt)
 526                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 527                         this_attr->c, this_attr->address)) {
 528                 case IIO_VAL_INT_PLUS_MICRO:
 529                         fract_mult = 100000;
 530                         break;
 531                 case IIO_VAL_INT_PLUS_NANO:
 532                         fract_mult = 100000000;
 533                         break;
 534                 default:
 535                         return -EINVAL;
 536                 }
 537
 538         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 539         if (ret)
 540                 return ret;
 541
 542         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 543                                          integer, fract, this_attr->address);
 544         if (ret)
 545                 return ret;
 546
 547         return len;
 548 }
 549
 550 static
 551 int __iio_device_attr_init(struct device_attribute *dev_attr,
 552                            const char *postfix,
 553                            struct iio_chan_spec const *chan,
 554                            ssize_t (*readfunc)(struct device *dev,
 555                                                struct device_attribute *attr,
 556                                                char *buf),
 557                            ssize_t (*writefunc)(struct device *dev,
 558                                                 struct device_attribute *attr,
 559                                                 const char *buf,
 560                                                 size_t len),
 561                            enum iio_shared_by shared_by)
 562 {
 563         int ret = 0;
 564         char *name = NULL;
 565         char *full_postfix;
 566         sysfs_attr_init(&dev_attr->attr);
 567
 568         /* Build up postfix of <extend_name>_<modifier>_postfix */
 569         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 570                 if (chan->extend_name)
 571                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 572                                                  iio_modifier_names[chan
 573                                                                     ->channel2],
 574                                                  chan->extend_name,
 575                                                  postfix);
 576                 else
 577                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 578                                                  iio_modifier_names[chan
 579                                                                     ->channel2],
 580                                                  postfix);
 581         } else {
 582                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 583                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 584                 else
 585                         full_postfix = kasprintf(GFP_KERNEL,
 586                                                  "%s_%s",
 587                                                  chan->extend_name,
 588                                                  postfix);
 589         }
 590         if (full_postfix == NULL)
 591                 return -ENOMEM;
 592
 593         if (chan->differential) { /* Differential can not have modifier */
 594                 switch (shared_by) {
 595                 case IIO_SHARED_BY_ALL:
 596                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 597                         break;
 598                 case IIO_SHARED_BY_DIR:
 599                         name = kasprintf(GFP_KERNEL, "%s_%s",
 600                                                 iio_direction[chan->output],
 601                                                 full_postfix);
 602                         break;
 603                 case IIO_SHARED_BY_TYPE:
 604                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 605                                             iio_direction[chan->output],
 606                                             iio_chan_type_name_spec[chan->type],
 607                                             iio_chan_type_name_spec[chan->type],
 608                                             full_postfix);
 609                         break;
 610                 case IIO_SEPARATE:
 611                         if (!chan->indexed) {
 612                                 WARN_ON("Differential channels must be indexed\n");
 613                                 ret = -EINVAL;
 614                                 goto error_free_full_postfix;
 615                         }
 616                         name = kasprintf(GFP_KERNEL,
 617                                             "%s_%s%d-%s%d_%s",
 618                                             iio_direction[chan->output],
 619                                             iio_chan_type_name_spec[chan->type],
 620                                             chan->channel,
 621                                             iio_chan_type_name_spec[chan->type],
 622                                             chan->channel2,
 623                                             full_postfix);
 624                         break;
 625                 }
 626         } else { /* Single ended */
 627                 switch (shared_by) {
 628                 case IIO_SHARED_BY_ALL:
 629                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 630                         break;
 631                 case IIO_SHARED_BY_DIR:
 632                         name = kasprintf(GFP_KERNEL, "%s_%s",
 633                                                 iio_direction[chan->output],
 634                                                 full_postfix);
 635                         break;
 636                 case IIO_SHARED_BY_TYPE:
 637                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 638                                             iio_direction[chan->output],
 639                                             iio_chan_type_name_spec[chan->type],
 640                                             full_postfix);
 641                         break;
 642
 643                 case IIO_SEPARATE:
 644                         if (chan->indexed)
 645                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 646                                                     iio_direction[chan->output],
 647                                                     iio_chan_type_name_spec[chan->type],
 648                                                     chan->channel,
 649                                                     full_postfix);
 650                         else
 651                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 652                                                     iio_direction[chan->output],
 653                                                     iio_chan_type_name_spec[chan->type],
 654                                                     full_postfix);
 655                         break;
 656                 }
 657         }
 658         if (name == NULL) {
 659                 ret = -ENOMEM;
 660                 goto error_free_full_postfix;
 661         }
 662         dev_attr->attr.name = name;
 663
 664         if (readfunc) {
 665                 dev_attr->attr.mode |= S_IRUGO;
 666                 dev_attr->show = readfunc;
 667         }
 668
 669         if (writefunc) {
 670                 dev_attr->attr.mode |= S_IWUSR;
 671                 dev_attr->store = writefunc;
 672         }
 673
 674 error_free_full_postfix:
 675         kfree(full_postfix);
 676
 677         return ret;
 678 }
 679
 680 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 681 {
 682         kfree(dev_attr->attr.name);
 683 }
 684
 685 int __iio_add_chan_devattr(const char *postfix,
 686                            struct iio_chan_spec const *chan,
 687                            ssize_t (*readfunc)(struct device *dev,
 688                                                struct device_attribute *attr,
 689                                                char *buf),
 690                            ssize_t (*writefunc)(struct device *dev,
 691                                                 struct device_attribute *attr,
 692                                                 const char *buf,
 693                                                 size_t len),
 694                            u64 mask,
 695                            enum iio_shared_by shared_by,
 696                            struct device *dev,
 697                            struct list_head *attr_list)
 698 {
 699         int ret;
 700         struct iio_dev_attr *iio_attr, *t;
 701
 702         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
 703         if (iio_attr == NULL)
 704                 return -ENOMEM;
 705         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 706                                      postfix, chan,
 707                                      readfunc, writefunc, shared_by);
 708         if (ret)
 709                 goto error_iio_dev_attr_free;
 710         iio_attr->c = chan;
 711         iio_attr->address = mask;
 712         list_for_each_entry(t, attr_list, l)
 713                 if (strcmp(t->dev_attr.attr.name,
 714                            iio_attr->dev_attr.attr.name) == 0) {
 715                         if (shared_by == IIO_SEPARATE)
 716                                 dev_err(dev, "tried to double register : %s\n",
 717                                         t->dev_attr.attr.name);
 718                         ret = -EBUSY;
 719                         goto error_device_attr_deinit;
 720                 }
 721         list_add(&iio_attr->l, attr_list);
 722
 723         return 0;
 724
 725 error_device_attr_deinit:
 726         __iio_device_attr_deinit(&iio_attr->dev_attr);
 727 error_iio_dev_attr_free:
 728         kfree(iio_attr);
 729         return ret;
 730 }
 731
 732 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
 733                                          struct iio_chan_spec const *chan,
 734                                          enum iio_shared_by shared_by,
 735                                          const long *infomask)
 736 {
 737         int i, ret, attrcount = 0;
 738
 739         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
 740                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
 741                         return -EINVAL;
 742                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
 743                                              chan,
 744                                              &iio_read_channel_info,
 745                                              &iio_write_channel_info,
 746                                              i,
 747                                              shared_by,
 748                                              &indio_dev->dev,
 749                                              &indio_dev->channel_attr_list);
 750                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
 751                         continue;
 752                 else if (ret < 0)
 753                         return ret;
 754                 attrcount++;
 755         }
 756
 757         return attrcount;
 758 }
 759
 760 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 761                                         struct iio_chan_spec const *chan)
 762 {
 763         int ret, attrcount = 0;
 764         const struct iio_chan_spec_ext_info *ext_info;
 765
 766         if (chan->channel < 0)
 767                 return 0;
 768         ret = iio_device_add_info_mask_type(indio_dev, chan,
 769                                             IIO_SEPARATE,
 770                                             &chan->info_mask_separate);
 771         if (ret < 0)
 772                 return ret;
 773         attrcount += ret;
 774
 775         ret = iio_device_add_info_mask_type(indio_dev, chan,
 776                                             IIO_SHARED_BY_TYPE,
 777                                             &chan->info_mask_shared_by_type);
 778         if (ret < 0)
 779                 return ret;
 780         attrcount += ret;
 781
 782         ret = iio_device_add_info_mask_type(indio_dev, chan,
 783                                             IIO_SHARED_BY_DIR,
 784                                             &chan->info_mask_shared_by_dir);
 785         if (ret < 0)
 786                 return ret;
 787         attrcount += ret;
 788
 789         ret = iio_device_add_info_mask_type(indio_dev, chan,
 790                                             IIO_SHARED_BY_ALL,
 791                                             &chan->info_mask_shared_by_all);
 792         if (ret < 0)
 793                 return ret;
 794         attrcount += ret;
 795
 796         if (chan->ext_info) {
 797                 unsigned int i = 0;
 798                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 799                         ret = __iio_add_chan_devattr(ext_info->name,
 800                                         chan,
 801                                         ext_info->read ?
 802                                             &iio_read_channel_ext_info : NULL,
 803                                         ext_info->write ?
 804                                             &iio_write_channel_ext_info : NULL,
 805                                         i,
 806                                         ext_info->shared,
 807                                         &indio_dev->dev,
 808                                         &indio_dev->channel_attr_list);
 809                         i++;
 810                         if (ret == -EBUSY && ext_info->shared)
 811                                 continue;
 812
 813                         if (ret)
 814                                 return ret;
 815
 816                         attrcount++;
 817                 }
 818         }
 819
 820         return attrcount;
 821 }
 822
 823 /**
 824  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
 825  * @attr_list: List of IIO device attributes
 826  *
 827  * This function frees the memory allocated for each of the IIO device
 828  * attributes in the list. Note: if you want to reuse the list after calling
 829  * this function you have to reinitialize it using INIT_LIST_HEAD().
 830  */
 831 void iio_free_chan_devattr_list(struct list_head *attr_list)
 832 {
 833         struct iio_dev_attr *p, *n;
 834
 835         list_for_each_entry_safe(p, n, attr_list, l) {
 836                 kfree(p->dev_attr.attr.name);
 837                 kfree(p);
 838         }
 839 }
 840
 841 static ssize_t iio_show_dev_name(struct device *dev,
 842                                  struct device_attribute *attr,
 843                                  char *buf)
 844 {
 845         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 846         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
 847 }
 848
 849 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 850
 851 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 852 {
 853         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 854         struct iio_dev_attr *p;
 855         struct attribute **attr;
 856
 857         /* First count elements in any existing group */
 858         if (indio_dev->info->attrs) {
 859                 attr = indio_dev->info->attrs->attrs;
 860                 while (*attr++ != NULL)
 861                         attrcount_orig++;
 862         }
 863         attrcount = attrcount_orig;
 864         /*
 865          * New channel registration method - relies on the fact a group does
 866          * not need to be initialized if its name is NULL.
 867          */
 868         if (indio_dev->channels)
 869                 for (i = 0; i < indio_dev->num_channels; i++) {
 870                         ret = iio_device_add_channel_sysfs(indio_dev,
 871                                                            &indio_dev
 872                                                            ->channels[i]);
 873                         if (ret < 0)
 874                                 goto error_clear_attrs;
 875                         attrcount += ret;
 876                 }
 877
 878         if (indio_dev->name)
 879                 attrcount++;
 880
 881         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 882                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 883                                                    GFP_KERNEL);
 884         if (indio_dev->chan_attr_group.attrs == NULL) {
 885                 ret = -ENOMEM;
 886                 goto error_clear_attrs;
 887         }
 888         /* Copy across original attributes */
 889         if (indio_dev->info->attrs)
 890                 memcpy(indio_dev->chan_attr_group.attrs,
 891                        indio_dev->info->attrs->attrs,
 892                        sizeof(indio_dev->chan_attr_group.attrs[0])
 893                        *attrcount_orig);
 894         attrn = attrcount_orig;
 895         /* Add all elements from the list. */
 896         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 897                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 898         if (indio_dev->name)
 899                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 900
 901         indio_dev->groups[indio_dev->groupcounter++] =
 902                 &indio_dev->chan_attr_group;
 903
 904         return 0;
 905
 906 error_clear_attrs:
 907         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 908
 909         return ret;
 910 }
 911
 912 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 913 {
 914
 915         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 916         kfree(indio_dev->chan_attr_group.attrs);
 917 }
 918
 919 static void iio_dev_release(struct device *device)
 920 {
 921         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 922         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 923                 iio_device_unregister_trigger_consumer(indio_dev);
 924         iio_device_unregister_eventset(indio_dev);
 925         iio_device_unregister_sysfs(indio_dev);
 926
 927         iio_buffer_put(indio_dev->buffer);
 928
 929         ida_simple_remove(&iio_ida, indio_dev->id);
 930         kfree(indio_dev);
 931 }
 932
 933 struct device_type iio_device_type = {
 934         .name = "iio_device",
 935         .release = iio_dev_release,
 936 };
 937
 938 /**
 939  * iio_device_alloc() - allocate an iio_dev from a driver
 940  * @sizeof_priv:        Space to allocate for private structure.
 941  **/
 942 struct iio_dev *iio_device_alloc(int sizeof_priv)
 943 {
 944         struct iio_dev *dev;
 945         size_t alloc_size;
 946
 947         alloc_size = sizeof(struct iio_dev);
 948         if (sizeof_priv) {
 949                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 950                 alloc_size += sizeof_priv;
 951         }
 952         /* ensure 32-byte alignment of whole construct ? */
 953         alloc_size += IIO_ALIGN - 1;
 954
 955         dev = kzalloc(alloc_size, GFP_KERNEL);
 956
 957         if (dev) {
 958                 dev->dev.groups = dev->groups;
 959                 dev->dev.type = &iio_device_type;
 960                 dev->dev.bus = &iio_bus_type;
 961                 device_initialize(&dev->dev);
 962                 dev_set_drvdata(&dev->dev, (void *)dev);
 963                 mutex_init(&dev->mlock);
 964                 mutex_init(&dev->info_exist_lock);
 965                 INIT_LIST_HEAD(&dev->channel_attr_list);
 966
 967                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 968                 if (dev->id < 0) {
 969                         /* cannot use a dev_err as the name isn't available */
 970                         pr_err("failed to get device id\n");
 971                         kfree(dev);
 972                         return NULL;
 973                 }
 974                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 975                 INIT_LIST_HEAD(&dev->buffer_list);
 976         }
 977
 978         return dev;
 979 }
 980 EXPORT_SYMBOL(iio_device_alloc);
 981
 982 /**
 983  * iio_device_free() - free an iio_dev from a driver
 984  * @dev:                the iio_dev associated with the device
 985  **/
 986 void iio_device_free(struct iio_dev *dev)
 987 {
 988         if (dev)
 989                 put_device(&dev->dev);
 990 }
 991 EXPORT_SYMBOL(iio_device_free);
 992
 993 static void devm_iio_device_release(struct device *dev, void *res)
 994 {
 995         iio_device_free(*(struct iio_dev **)res);
 996 }
 997
 998 static int devm_iio_device_match(struct device *dev, void *res, void *data)
 999 {
1000         struct iio_dev **r = res;
1001         if (!r || !*r) {
1002                 WARN_ON(!r || !*r);
1003                 return 0;
1004         }
1005         return *r == data;
1006 }
1007
1008 /**
1009  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1010  * @dev:                Device to allocate iio_dev for
1011  * @sizeof_priv:        Space to allocate for private structure.
1012  *
1013  * Managed iio_device_alloc. iio_dev allocated with this function is
1014  * automatically freed on driver detach.
1015  *
1016  * If an iio_dev allocated with this function needs to be freed separately,
1017  * devm_iio_device_free() must be used.
1018  *
1019  * RETURNS:
1020  * Pointer to allocated iio_dev on success, NULL on failure.
1021  */
1022 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1023 {
1024         struct iio_dev **ptr, *iio_dev;
1025
1026         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1027                            GFP_KERNEL);
1028         if (!ptr)
1029                 return NULL;
1030
1031         /* use raw alloc_dr for kmalloc caller tracing */
1032         iio_dev = iio_device_alloc(sizeof_priv);
1033         if (iio_dev) {
1034                 *ptr = iio_dev;
1035                 devres_add(dev, ptr);
1036         } else {
1037                 devres_free(ptr);
1038         }
1039
1040         return iio_dev;
1041 }
1042 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1043
1044 /**
1045  * devm_iio_device_free - Resource-managed iio_device_free()
1046  * @dev:                Device this iio_dev belongs to
1047  * @iio_dev:            the iio_dev associated with the device
1048  *
1049  * Free iio_dev allocated with devm_iio_device_alloc().
1050  */
1051 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1052 {
1053         int rc;
1054
1055         rc = devres_release(dev, devm_iio_device_release,
1056                             devm_iio_device_match, iio_dev);
1057         WARN_ON(rc);
1058 }
1059 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1060
1061 /**
1062  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1063  **/
1064 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1065 {
1066         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1067                                                 struct iio_dev, chrdev);
1068
1069         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1070                 return -EBUSY;
1071
1072         iio_device_get(indio_dev);
1073
1074         filp->private_data = indio_dev;
1075
1076         return 0;
1077 }
1078
1079 /**
1080  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1081  **/
1082 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1083 {
1084         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1085                                                 struct iio_dev, chrdev);
1086         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1087         iio_device_put(indio_dev);
1088
1089         return 0;
1090 }
1091
1092 /* Somewhat of a cross file organization violation - ioctls here are actually
1093  * event related */
1094 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1095 {
1096         struct iio_dev *indio_dev = filp->private_data;
1097         int __user *ip = (int __user *)arg;
1098         int fd;
1099
1100         if (!indio_dev->info)
1101                 return -ENODEV;
1102
1103         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1104                 fd = iio_event_getfd(indio_dev);
1105                 if (copy_to_user(ip, &fd, sizeof(fd)))
1106                         return -EFAULT;
1107                 return 0;
1108         }
1109         return -EINVAL;
1110 }
1111
1112 static const struct file_operations iio_buffer_fileops = {
1113         .read = iio_buffer_read_first_n_outer_addr,
1114         .release = iio_chrdev_release,
1115         .open = iio_chrdev_open,
1116         .poll = iio_buffer_poll_addr,
1117         .owner = THIS_MODULE,
1118         .llseek = noop_llseek,
1119         .unlocked_ioctl = iio_ioctl,
1120         .compat_ioctl = iio_ioctl,
1121 };
1122
1123 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1124
1125 /**
1126  * iio_device_register() - register a device with the IIO subsystem
1127  * @indio_dev:          Device structure filled by the device driver
1128  **/
1129 int iio_device_register(struct iio_dev *indio_dev)
1130 {
1131         int ret;
1132
1133         /* If the calling driver did not initialize of_node, do it here */
1134         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1135                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1136
1137         /* configure elements for the chrdev */
1138         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1139
1140         ret = iio_device_register_debugfs(indio_dev);
1141         if (ret) {
1142                 dev_err(indio_dev->dev.parent,
1143                         "Failed to register debugfs interfaces\n");
1144                 return ret;
1145         }
1146         ret = iio_device_register_sysfs(indio_dev);
1147         if (ret) {
1148                 dev_err(indio_dev->dev.parent,
1149                         "Failed to register sysfs interfaces\n");
1150                 goto error_unreg_debugfs;
1151         }
1152         ret = iio_device_register_eventset(indio_dev);
1153         if (ret) {
1154                 dev_err(indio_dev->dev.parent,
1155                         "Failed to register event set\n");
1156                 goto error_free_sysfs;
1157         }
1158         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
1159                 iio_device_register_trigger_consumer(indio_dev);
1160
1161         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1162                 indio_dev->setup_ops == NULL)
1163                 indio_dev->setup_ops = &noop_ring_setup_ops;
1164
1165         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1166         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1167         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1168         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1169         if (ret < 0)
1170                 goto error_unreg_eventset;
1171
1172         ret = device_add(&indio_dev->dev);
1173         if (ret < 0)
1174                 goto error_cdev_del;
1175
1176         return 0;
1177 error_cdev_del:
1178         cdev_del(&indio_dev->chrdev);
1179 error_unreg_eventset:
1180         iio_device_unregister_eventset(indio_dev);
1181 error_free_sysfs:
1182         iio_device_unregister_sysfs(indio_dev);
1183 error_unreg_debugfs:
1184         iio_device_unregister_debugfs(indio_dev);
1185         return ret;
1186 }
1187 EXPORT_SYMBOL(iio_device_register);
1188
1189 /**
1190  * iio_device_unregister() - unregister a device from the IIO subsystem
1191  * @indio_dev:          Device structure representing the device.
1192  **/
1193 void iio_device_unregister(struct iio_dev *indio_dev)
1194 {
1195         mutex_lock(&indio_dev->info_exist_lock);
1196
1197         device_del(&indio_dev->dev);
1198
1199         if (indio_dev->chrdev.dev)
1200                 cdev_del(&indio_dev->chrdev);
1201         iio_device_unregister_debugfs(indio_dev);
1202
1203         iio_disable_all_buffers(indio_dev);
1204
1205         indio_dev->info = NULL;
1206
1207         iio_device_wakeup_eventset(indio_dev);
1208         iio_buffer_wakeup_poll(indio_dev);
1209
1210         mutex_unlock(&indio_dev->info_exist_lock);
1211 }
1212 EXPORT_SYMBOL(iio_device_unregister);
1213
1214 static void devm_iio_device_unreg(struct device *dev, void *res)
1215 {
1216         iio_device_unregister(*(struct iio_dev **)res);
1217 }
1218
1219 /**
1220  * devm_iio_device_register - Resource-managed iio_device_register()
1221  * @dev:        Device to allocate iio_dev for
1222  * @indio_dev:  Device structure filled by the device driver
1223  *
1224  * Managed iio_device_register.  The IIO device registered with this
1225  * function is automatically unregistered on driver detach. This function
1226  * calls iio_device_register() internally. Refer to that function for more
1227  * information.
1228  *
1229  * If an iio_dev registered with this function needs to be unregistered
1230  * separately, devm_iio_device_unregister() must be used.
1231  *
1232  * RETURNS:
1233  * 0 on success, negative error number on failure.
1234  */
1235 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1236 {
1237         struct iio_dev **ptr;
1238         int ret;
1239
1240         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1241         if (!ptr)
1242                 return -ENOMEM;
1243
1244         *ptr = indio_dev;
1245         ret = iio_device_register(indio_dev);
1246         if (!ret)
1247                 devres_add(dev, ptr);
1248         else
1249                 devres_free(ptr);
1250
1251         return ret;
1252 }
1253 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1254
1255 /**
1256  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1257  * @dev:        Device this iio_dev belongs to
1258  * @indio_dev:  the iio_dev associated with the device
1259  *
1260  * Unregister iio_dev registered with devm_iio_device_register().
1261  */
1262 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1263 {
1264         int rc;
1265
1266         rc = devres_release(dev, devm_iio_device_unreg,
1267                             devm_iio_device_match, indio_dev);
1268         WARN_ON(rc);
1269 }
1270 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1271
1272 subsys_initcall(iio_init);
1273 module_exit(iio_exit);
1274
1275 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1276 MODULE_DESCRIPTION("Industrial I/O core");
1277 MODULE_LICENSE("GPL");