drivers/iio/industrialio-core.c

   1 /* The industrial I/O core
   2  *
   3  * Copyright (c) 2008 Jonathan Cameron
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * Based on elements of hwmon and input subsystems.
  10  */
  11
  12 #define pr_fmt(fmt) "iio-core: " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/idr.h>
  17 #include <linux/kdev_t.h>
  18 #include <linux/err.h>
  19 #include <linux/device.h>
  20 #include <linux/fs.h>
  21 #include <linux/poll.h>
  22 #include <linux/sched.h>
  23 #include <linux/wait.h>
  24 #include <linux/cdev.h>
  25 #include <linux/slab.h>
  26 #include <linux/anon_inodes.h>
  27 #include <linux/debugfs.h>
  28 #include <linux/iio/iio.h>
  29 #include "iio_core.h"
  30 #include "iio_core_trigger.h"
  31 #include <linux/iio/sysfs.h>
  32 #include <linux/iio/events.h>
  33 #include <linux/iio/buffer.h>
  34
  35 /* IDA to assign each registered device a unique id */
  36 static DEFINE_IDA(iio_ida);
  37
  38 static dev_t iio_devt;
  39
  40 #define IIO_DEV_MAX 256
  41 struct bus_type iio_bus_type = {
  42         .name = "iio",
  43 };
  44 EXPORT_SYMBOL(iio_bus_type);
  45
  46 static struct dentry *iio_debugfs_dentry;
  47
  48 static const char * const iio_direction[] = {
  49         [0] = "in",
  50         [1] = "out",
  51 };
  52
  53 static const char * const iio_chan_type_name_spec[] = {
  54         [IIO_VOLTAGE] = "voltage",
  55         [IIO_CURRENT] = "current",
  56         [IIO_POWER] = "power",
  57         [IIO_ACCEL] = "accel",
  58         [IIO_ANGL_VEL] = "anglvel",
  59         [IIO_MAGN] = "magn",
  60         [IIO_LIGHT] = "illuminance",
  61         [IIO_INTENSITY] = "intensity",
  62         [IIO_PROXIMITY] = "proximity",
  63         [IIO_TEMP] = "temp",
  64         [IIO_INCLI] = "incli",
  65         [IIO_ROT] = "rot",
  66         [IIO_ANGL] = "angl",
  67         [IIO_TIMESTAMP] = "timestamp",
  68         [IIO_CAPACITANCE] = "capacitance",
  69         [IIO_ALTVOLTAGE] = "altvoltage",
  70         [IIO_CCT] = "cct",
  71         [IIO_PRESSURE] = "pressure",
  72         [IIO_HUMIDITYRELATIVE] = "humidityrelative",
  73 };
  74
  75 static const char * const iio_modifier_names[] = {
  76         [IIO_MOD_X] = "x",
  77         [IIO_MOD_Y] = "y",
  78         [IIO_MOD_Z] = "z",
  79         [IIO_MOD_ROOT_SUM_SQUARED_X_Y] = "sqrt(x^2+y^2)",
  80         [IIO_MOD_SUM_SQUARED_X_Y_Z] = "x^2+y^2+z^2",
  81         [IIO_MOD_LIGHT_BOTH] = "both",
  82         [IIO_MOD_LIGHT_IR] = "ir",
  83         [IIO_MOD_LIGHT_CLEAR] = "clear",
  84         [IIO_MOD_LIGHT_RED] = "red",
  85         [IIO_MOD_LIGHT_GREEN] = "green",
  86         [IIO_MOD_LIGHT_BLUE] = "blue",
  87         [IIO_MOD_QUATERNION] = "quaternion",
  88         [IIO_MOD_TEMP_AMBIENT] = "ambient",
  89         [IIO_MOD_TEMP_OBJECT] = "object",
  90         [IIO_MOD_NORTH_MAGN] = "from_north_magnetic",
  91         [IIO_MOD_NORTH_TRUE] = "from_north_true",
  92         [IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
  93         [IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
  94 };
  95
  96 /* relies on pairs of these shared then separate */
  97 static const char * const iio_chan_info_postfix[] = {
  98         [IIO_CHAN_INFO_RAW] = "raw",
  99         [IIO_CHAN_INFO_PROCESSED] = "input",
 100         [IIO_CHAN_INFO_SCALE] = "scale",
 101         [IIO_CHAN_INFO_OFFSET] = "offset",
 102         [IIO_CHAN_INFO_CALIBSCALE] = "calibscale",
 103         [IIO_CHAN_INFO_CALIBBIAS] = "calibbias",
 104         [IIO_CHAN_INFO_PEAK] = "peak_raw",
 105         [IIO_CHAN_INFO_PEAK_SCALE] = "peak_scale",
 106         [IIO_CHAN_INFO_QUADRATURE_CORRECTION_RAW] = "quadrature_correction_raw",
 107         [IIO_CHAN_INFO_AVERAGE_RAW] = "mean_raw",
 108         [IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY]
 109         = "filter_low_pass_3db_frequency",
 110         [IIO_CHAN_INFO_SAMP_FREQ] = "sampling_frequency",
 111         [IIO_CHAN_INFO_FREQUENCY] = "frequency",
 112         [IIO_CHAN_INFO_PHASE] = "phase",
 113         [IIO_CHAN_INFO_HARDWAREGAIN] = "hardwaregain",
 114         [IIO_CHAN_INFO_HYSTERESIS] = "hysteresis",
 115         [IIO_CHAN_INFO_INT_TIME] = "integration_time",
 116 };
 117
 118 /**
 119  * iio_find_channel_from_si() - get channel from its scan index
 120  * @indio_dev:          device
 121  * @si:                 scan index to match
 122  */
 123 const struct iio_chan_spec
 124 *iio_find_channel_from_si(struct iio_dev *indio_dev, int si)
 125 {
 126         int i;
 127
 128         for (i = 0; i < indio_dev->num_channels; i++)
 129                 if (indio_dev->channels[i].scan_index == si)
 130                         return &indio_dev->channels[i];
 131         return NULL;
 132 }
 133
 134 /* This turns up an awful lot */
 135 ssize_t iio_read_const_attr(struct device *dev,
 136                             struct device_attribute *attr,
 137                             char *buf)
 138 {
 139         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 140 }
 141 EXPORT_SYMBOL(iio_read_const_attr);
 142
 143 static int __init iio_init(void)
 144 {
 145         int ret;
 146
 147         /* Register sysfs bus */
 148         ret  = bus_register(&iio_bus_type);
 149         if (ret < 0) {
 150                 pr_err("could not register bus type\n");
 151                 goto error_nothing;
 152         }
 153
 154         ret = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 155         if (ret < 0) {
 156                 pr_err("failed to allocate char dev region\n");
 157                 goto error_unregister_bus_type;
 158         }
 159
 160         iio_debugfs_dentry = debugfs_create_dir("iio", NULL);
 161
 162         return 0;
 163
 164 error_unregister_bus_type:
 165         bus_unregister(&iio_bus_type);
 166 error_nothing:
 167         return ret;
 168 }
 169
 170 static void __exit iio_exit(void)
 171 {
 172         if (iio_devt)
 173                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 174         bus_unregister(&iio_bus_type);
 175         debugfs_remove(iio_debugfs_dentry);
 176 }
 177
 178 #if defined(CONFIG_DEBUG_FS)
 179 static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 180                               size_t count, loff_t *ppos)
 181 {
 182         struct iio_dev *indio_dev = file->private_data;
 183         char buf[20];
 184         unsigned val = 0;
 185         ssize_t len;
 186         int ret;
 187
 188         ret = indio_dev->info->debugfs_reg_access(indio_dev,
 189                                                   indio_dev->cached_reg_addr,
 190                                                   0, &val);
 191         if (ret)
 192                 dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
 193
 194         len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 195
 196         return simple_read_from_buffer(userbuf, count, ppos, buf, len);
 197 }
 198
 199 static ssize_t iio_debugfs_write_reg(struct file *file,
 200                      const char __user *userbuf, size_t count, loff_t *ppos)
 201 {
 202         struct iio_dev *indio_dev = file->private_data;
 203         unsigned reg, val;
 204         char buf[80];
 205         int ret;
 206
 207         count = min_t(size_t, count, (sizeof(buf)-1));
 208         if (copy_from_user(buf, userbuf, count))
 209                 return -EFAULT;
 210
 211         buf[count] = 0;
 212
 213         ret = sscanf(buf, "%i %i", &reg, &val);
 214
 215         switch (ret) {
 216         case 1:
 217                 indio_dev->cached_reg_addr = reg;
 218                 break;
 219         case 2:
 220                 indio_dev->cached_reg_addr = reg;
 221                 ret = indio_dev->info->debugfs_reg_access(indio_dev, reg,
 222                                                           val, NULL);
 223                 if (ret) {
 224                         dev_err(indio_dev->dev.parent, "%s: write failed\n",
 225                                 __func__);
 226                         return ret;
 227                 }
 228                 break;
 229         default:
 230                 return -EINVAL;
 231         }
 232
 233         return count;
 234 }
 235
 236 static const struct file_operations iio_debugfs_reg_fops = {
 237         .open = simple_open,
 238         .read = iio_debugfs_read_reg,
 239         .write = iio_debugfs_write_reg,
 240 };
 241
 242 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 243 {
 244         debugfs_remove_recursive(indio_dev->debugfs_dentry);
 245 }
 246
 247 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 248 {
 249         struct dentry *d;
 250
 251         if (indio_dev->info->debugfs_reg_access == NULL)
 252                 return 0;
 253
 254         if (!iio_debugfs_dentry)
 255                 return 0;
 256
 257         indio_dev->debugfs_dentry =
 258                 debugfs_create_dir(dev_name(&indio_dev->dev),
 259                                    iio_debugfs_dentry);
 260         if (indio_dev->debugfs_dentry == NULL) {
 261                 dev_warn(indio_dev->dev.parent,
 262                          "Failed to create debugfs directory\n");
 263                 return -EFAULT;
 264         }
 265
 266         d = debugfs_create_file("direct_reg_access", 0644,
 267                                 indio_dev->debugfs_dentry,
 268                                 indio_dev, &iio_debugfs_reg_fops);
 269         if (!d) {
 270                 iio_device_unregister_debugfs(indio_dev);
 271                 return -ENOMEM;
 272         }
 273
 274         return 0;
 275 }
 276 #else
 277 static int iio_device_register_debugfs(struct iio_dev *indio_dev)
 278 {
 279         return 0;
 280 }
 281
 282 static void iio_device_unregister_debugfs(struct iio_dev *indio_dev)
 283 {
 284 }
 285 #endif /* CONFIG_DEBUG_FS */
 286
 287 static ssize_t iio_read_channel_ext_info(struct device *dev,
 288                                      struct device_attribute *attr,
 289                                      char *buf)
 290 {
 291         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 292         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 293         const struct iio_chan_spec_ext_info *ext_info;
 294
 295         ext_info = &this_attr->c->ext_info[this_attr->address];
 296
 297         return ext_info->read(indio_dev, ext_info->private, this_attr->c, buf);
 298 }
 299
 300 static ssize_t iio_write_channel_ext_info(struct device *dev,
 301                                      struct device_attribute *attr,
 302                                      const char *buf,
 303                                          size_t len)
 304 {
 305         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 306         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 307         const struct iio_chan_spec_ext_info *ext_info;
 308
 309         ext_info = &this_attr->c->ext_info[this_attr->address];
 310
 311         return ext_info->write(indio_dev, ext_info->private,
 312                                this_attr->c, buf, len);
 313 }
 314
 315 ssize_t iio_enum_available_read(struct iio_dev *indio_dev,
 316         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 317 {
 318         const struct iio_enum *e = (const struct iio_enum *)priv;
 319         unsigned int i;
 320         size_t len = 0;
 321
 322         if (!e->num_items)
 323                 return 0;
 324
 325         for (i = 0; i < e->num_items; ++i)
 326                 len += scnprintf(buf + len, PAGE_SIZE - len, "%s ", e->items[i]);
 327
 328         /* replace last space with a newline */
 329         buf[len - 1] = '\n';
 330
 331         return len;
 332 }
 333 EXPORT_SYMBOL_GPL(iio_enum_available_read);
 334
 335 ssize_t iio_enum_read(struct iio_dev *indio_dev,
 336         uintptr_t priv, const struct iio_chan_spec *chan, char *buf)
 337 {
 338         const struct iio_enum *e = (const struct iio_enum *)priv;
 339         int i;
 340
 341         if (!e->get)
 342                 return -EINVAL;
 343
 344         i = e->get(indio_dev, chan);
 345         if (i < 0)
 346                 return i;
 347         else if (i >= e->num_items)
 348                 return -EINVAL;
 349
 350         return snprintf(buf, PAGE_SIZE, "%s\n", e->items[i]);
 351 }
 352 EXPORT_SYMBOL_GPL(iio_enum_read);
 353
 354 ssize_t iio_enum_write(struct iio_dev *indio_dev,
 355         uintptr_t priv, const struct iio_chan_spec *chan, const char *buf,
 356         size_t len)
 357 {
 358         const struct iio_enum *e = (const struct iio_enum *)priv;
 359         unsigned int i;
 360         int ret;
 361
 362         if (!e->set)
 363                 return -EINVAL;
 364
 365         for (i = 0; i < e->num_items; i++) {
 366                 if (sysfs_streq(buf, e->items[i]))
 367                         break;
 368         }
 369
 370         if (i == e->num_items)
 371                 return -EINVAL;
 372
 373         ret = e->set(indio_dev, chan, i);
 374         return ret ? ret : len;
 375 }
 376 EXPORT_SYMBOL_GPL(iio_enum_write);
 377
 378 /**
 379  * iio_format_value() - Formats a IIO value into its string representation
 380  * @buf: The buffer to which the formated value gets written
 381  * @type: One of the IIO_VAL_... constants. This decides how the val and val2
 382  *        parameters are formatted.
 383  * @vals: pointer to the values, exact meaning depends on the type parameter.
 384  */
 385 ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals)
 386 {
 387         unsigned long long tmp;
 388         bool scale_db = false;
 389
 390         switch (type) {
 391         case IIO_VAL_INT:
 392                 return sprintf(buf, "%d\n", vals[0]);
 393         case IIO_VAL_INT_PLUS_MICRO_DB:
 394                 scale_db = true;
 395         case IIO_VAL_INT_PLUS_MICRO:
 396                 if (vals[1] < 0)
 397                         return sprintf(buf, "-%ld.%06u%s\n", abs(vals[0]),
 398                                         -vals[1],
 399                                 scale_db ? " dB" : "");
 400                 else
 401                         return sprintf(buf, "%d.%06u%s\n", vals[0], vals[1],
 402                                 scale_db ? " dB" : "");
 403         case IIO_VAL_INT_PLUS_NANO:
 404                 if (vals[1] < 0)
 405                         return sprintf(buf, "-%ld.%09u\n", abs(vals[0]),
 406                                         -vals[1]);
 407                 else
 408                         return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 409         case IIO_VAL_FRACTIONAL:
 410                 tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]);
 411                 vals[1] = do_div(tmp, 1000000000LL);
 412                 vals[0] = tmp;
 413                 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 414         case IIO_VAL_FRACTIONAL_LOG2:
 415                 tmp = (s64)vals[0] * 1000000000LL >> vals[1];
 416                 vals[1] = do_div(tmp, 1000000000LL);
 417                 vals[0] = tmp;
 418                 return sprintf(buf, "%d.%09u\n", vals[0], vals[1]);
 419         case IIO_VAL_INT_MULTIPLE:
 420         {
 421                 int i;
 422                 int len = 0;
 423
 424                 for (i = 0; i < size; ++i)
 425                         len += snprintf(&buf[len], PAGE_SIZE - len, "%d ",
 426                                                                 vals[i]);
 427                 len += snprintf(&buf[len], PAGE_SIZE - len, "\n");
 428                 return len;
 429         }
 430         default:
 431                 return 0;
 432         }
 433 }
 434
 435 static ssize_t iio_read_channel_info(struct device *dev,
 436                                      struct device_attribute *attr,
 437                                      char *buf)
 438 {
 439         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 440         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 441         int vals[INDIO_MAX_RAW_ELEMENTS];
 442         int ret;
 443         int val_len = 2;
 444
 445         if (indio_dev->info->read_raw_multi)
 446                 ret = indio_dev->info->read_raw_multi(indio_dev, this_attr->c,
 447                                                         INDIO_MAX_RAW_ELEMENTS,
 448                                                         vals, &val_len,
 449                                                         this_attr->address);
 450         else
 451                 ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
 452                                     &vals[0], &vals[1], this_attr->address);
 453
 454         if (ret < 0)
 455                 return ret;
 456
 457         return iio_format_value(buf, ret, val_len, vals);
 458 }
 459
 460 /**
 461  * iio_str_to_fixpoint() - Parse a fixed-point number from a string
 462  * @str: The string to parse
 463  * @fract_mult: Multiplier for the first decimal place, should be a power of 10
 464  * @integer: The integer part of the number
 465  * @fract: The fractional part of the number
 466  *
 467  * Returns 0 on success, or a negative error code if the string could not be
 468  * parsed.
 469  */
 470 int iio_str_to_fixpoint(const char *str, int fract_mult,
 471         int *integer, int *fract)
 472 {
 473         int i = 0, f = 0;
 474         bool integer_part = true, negative = false;
 475
 476         if (str[0] == '-') {
 477                 negative = true;
 478                 str++;
 479         } else if (str[0] == '+') {
 480                 str++;
 481         }
 482
 483         while (*str) {
 484                 if ('0' <= *str && *str <= '9') {
 485                         if (integer_part) {
 486                                 i = i * 10 + *str - '0';
 487                         } else {
 488                                 f += fract_mult * (*str - '0');
 489                                 fract_mult /= 10;
 490                         }
 491                 } else if (*str == '\n') {
 492                         if (*(str + 1) == '\0')
 493                                 break;
 494                         else
 495                                 return -EINVAL;
 496                 } else if (*str == '.' && integer_part) {
 497                         integer_part = false;
 498                 } else {
 499                         return -EINVAL;
 500                 }
 501                 str++;
 502         }
 503
 504         if (negative) {
 505                 if (i)
 506                         i = -i;
 507                 else
 508                         f = -f;
 509         }
 510
 511         *integer = i;
 512         *fract = f;
 513
 514         return 0;
 515 }
 516 EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);
 517
 518 static ssize_t iio_write_channel_info(struct device *dev,
 519                                       struct device_attribute *attr,
 520                                       const char *buf,
 521                                       size_t len)
 522 {
 523         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 524         struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 525         int ret, fract_mult = 100000;
 526         int integer, fract;
 527
 528         /* Assumes decimal - precision based on number of digits */
 529         if (!indio_dev->info->write_raw)
 530                 return -EINVAL;
 531
 532         if (indio_dev->info->write_raw_get_fmt)
 533                 switch (indio_dev->info->write_raw_get_fmt(indio_dev,
 534                         this_attr->c, this_attr->address)) {
 535                 case IIO_VAL_INT_PLUS_MICRO:
 536                         fract_mult = 100000;
 537                         break;
 538                 case IIO_VAL_INT_PLUS_NANO:
 539                         fract_mult = 100000000;
 540                         break;
 541                 default:
 542                         return -EINVAL;
 543                 }
 544
 545         ret = iio_str_to_fixpoint(buf, fract_mult, &integer, &fract);
 546         if (ret)
 547                 return ret;
 548
 549         ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
 550                                          integer, fract, this_attr->address);
 551         if (ret)
 552                 return ret;
 553
 554         return len;
 555 }
 556
 557 static
 558 int __iio_device_attr_init(struct device_attribute *dev_attr,
 559                            const char *postfix,
 560                            struct iio_chan_spec const *chan,
 561                            ssize_t (*readfunc)(struct device *dev,
 562                                                struct device_attribute *attr,
 563                                                char *buf),
 564                            ssize_t (*writefunc)(struct device *dev,
 565                                                 struct device_attribute *attr,
 566                                                 const char *buf,
 567                                                 size_t len),
 568                            enum iio_shared_by shared_by)
 569 {
 570         int ret = 0;
 571         char *name = NULL;
 572         char *full_postfix;
 573         sysfs_attr_init(&dev_attr->attr);
 574
 575         /* Build up postfix of <extend_name>_<modifier>_postfix */
 576         if (chan->modified && (shared_by == IIO_SEPARATE)) {
 577                 if (chan->extend_name)
 578                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 579                                                  iio_modifier_names[chan
 580                                                                     ->channel2],
 581                                                  chan->extend_name,
 582                                                  postfix);
 583                 else
 584                         full_postfix = kasprintf(GFP_KERNEL, "%s_%s",
 585                                                  iio_modifier_names[chan
 586                                                                     ->channel2],
 587                                                  postfix);
 588         } else {
 589                 if (chan->extend_name == NULL || shared_by != IIO_SEPARATE)
 590                         full_postfix = kstrdup(postfix, GFP_KERNEL);
 591                 else
 592                         full_postfix = kasprintf(GFP_KERNEL,
 593                                                  "%s_%s",
 594                                                  chan->extend_name,
 595                                                  postfix);
 596         }
 597         if (full_postfix == NULL)
 598                 return -ENOMEM;
 599
 600         if (chan->differential) { /* Differential can not have modifier */
 601                 switch (shared_by) {
 602                 case IIO_SHARED_BY_ALL:
 603                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 604                         break;
 605                 case IIO_SHARED_BY_DIR:
 606                         name = kasprintf(GFP_KERNEL, "%s_%s",
 607                                                 iio_direction[chan->output],
 608                                                 full_postfix);
 609                         break;
 610                 case IIO_SHARED_BY_TYPE:
 611                         name = kasprintf(GFP_KERNEL, "%s_%s-%s_%s",
 612                                             iio_direction[chan->output],
 613                                             iio_chan_type_name_spec[chan->type],
 614                                             iio_chan_type_name_spec[chan->type],
 615                                             full_postfix);
 616                         break;
 617                 case IIO_SEPARATE:
 618                         if (!chan->indexed) {
 619                                 WARN_ON("Differential channels must be indexed\n");
 620                                 ret = -EINVAL;
 621                                 goto error_free_full_postfix;
 622                         }
 623                         name = kasprintf(GFP_KERNEL,
 624                                             "%s_%s%d-%s%d_%s",
 625                                             iio_direction[chan->output],
 626                                             iio_chan_type_name_spec[chan->type],
 627                                             chan->channel,
 628                                             iio_chan_type_name_spec[chan->type],
 629                                             chan->channel2,
 630                                             full_postfix);
 631                         break;
 632                 }
 633         } else { /* Single ended */
 634                 switch (shared_by) {
 635                 case IIO_SHARED_BY_ALL:
 636                         name = kasprintf(GFP_KERNEL, "%s", full_postfix);
 637                         break;
 638                 case IIO_SHARED_BY_DIR:
 639                         name = kasprintf(GFP_KERNEL, "%s_%s",
 640                                                 iio_direction[chan->output],
 641                                                 full_postfix);
 642                         break;
 643                 case IIO_SHARED_BY_TYPE:
 644                         name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 645                                             iio_direction[chan->output],
 646                                             iio_chan_type_name_spec[chan->type],
 647                                             full_postfix);
 648                         break;
 649
 650                 case IIO_SEPARATE:
 651                         if (chan->indexed)
 652                                 name = kasprintf(GFP_KERNEL, "%s_%s%d_%s",
 653                                                     iio_direction[chan->output],
 654                                                     iio_chan_type_name_spec[chan->type],
 655                                                     chan->channel,
 656                                                     full_postfix);
 657                         else
 658                                 name = kasprintf(GFP_KERNEL, "%s_%s_%s",
 659                                                     iio_direction[chan->output],
 660                                                     iio_chan_type_name_spec[chan->type],
 661                                                     full_postfix);
 662                         break;
 663                 }
 664         }
 665         if (name == NULL) {
 666                 ret = -ENOMEM;
 667                 goto error_free_full_postfix;
 668         }
 669         dev_attr->attr.name = name;
 670
 671         if (readfunc) {
 672                 dev_attr->attr.mode |= S_IRUGO;
 673                 dev_attr->show = readfunc;
 674         }
 675
 676         if (writefunc) {
 677                 dev_attr->attr.mode |= S_IWUSR;
 678                 dev_attr->store = writefunc;
 679         }
 680
 681 error_free_full_postfix:
 682         kfree(full_postfix);
 683
 684         return ret;
 685 }
 686
 687 static void __iio_device_attr_deinit(struct device_attribute *dev_attr)
 688 {
 689         kfree(dev_attr->attr.name);
 690 }
 691
 692 int __iio_add_chan_devattr(const char *postfix,
 693                            struct iio_chan_spec const *chan,
 694                            ssize_t (*readfunc)(struct device *dev,
 695                                                struct device_attribute *attr,
 696                                                char *buf),
 697                            ssize_t (*writefunc)(struct device *dev,
 698                                                 struct device_attribute *attr,
 699                                                 const char *buf,
 700                                                 size_t len),
 701                            u64 mask,
 702                            enum iio_shared_by shared_by,
 703                            struct device *dev,
 704                            struct list_head *attr_list)
 705 {
 706         int ret;
 707         struct iio_dev_attr *iio_attr, *t;
 708
 709         iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
 710         if (iio_attr == NULL)
 711                 return -ENOMEM;
 712         ret = __iio_device_attr_init(&iio_attr->dev_attr,
 713                                      postfix, chan,
 714                                      readfunc, writefunc, shared_by);
 715         if (ret)
 716                 goto error_iio_dev_attr_free;
 717         iio_attr->c = chan;
 718         iio_attr->address = mask;
 719         list_for_each_entry(t, attr_list, l)
 720                 if (strcmp(t->dev_attr.attr.name,
 721                            iio_attr->dev_attr.attr.name) == 0) {
 722                         if (shared_by == IIO_SEPARATE)
 723                                 dev_err(dev, "tried to double register : %s\n",
 724                                         t->dev_attr.attr.name);
 725                         ret = -EBUSY;
 726                         goto error_device_attr_deinit;
 727                 }
 728         list_add(&iio_attr->l, attr_list);
 729
 730         return 0;
 731
 732 error_device_attr_deinit:
 733         __iio_device_attr_deinit(&iio_attr->dev_attr);
 734 error_iio_dev_attr_free:
 735         kfree(iio_attr);
 736         return ret;
 737 }
 738
 739 static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
 740                                          struct iio_chan_spec const *chan,
 741                                          enum iio_shared_by shared_by,
 742                                          const long *infomask)
 743 {
 744         int i, ret, attrcount = 0;
 745
 746         for_each_set_bit(i, infomask, sizeof(infomask)*8) {
 747                 if (i >= ARRAY_SIZE(iio_chan_info_postfix))
 748                         return -EINVAL;
 749                 ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
 750                                              chan,
 751                                              &iio_read_channel_info,
 752                                              &iio_write_channel_info,
 753                                              i,
 754                                              shared_by,
 755                                              &indio_dev->dev,
 756                                              &indio_dev->channel_attr_list);
 757                 if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
 758                         continue;
 759                 else if (ret < 0)
 760                         return ret;
 761                 attrcount++;
 762         }
 763
 764         return attrcount;
 765 }
 766
 767 static int iio_device_add_channel_sysfs(struct iio_dev *indio_dev,
 768                                         struct iio_chan_spec const *chan)
 769 {
 770         int ret, attrcount = 0;
 771         const struct iio_chan_spec_ext_info *ext_info;
 772
 773         if (chan->channel < 0)
 774                 return 0;
 775         ret = iio_device_add_info_mask_type(indio_dev, chan,
 776                                             IIO_SEPARATE,
 777                                             &chan->info_mask_separate);
 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_TYPE,
 784                                             &chan->info_mask_shared_by_type);
 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_DIR,
 791                                             &chan->info_mask_shared_by_dir);
 792         if (ret < 0)
 793                 return ret;
 794         attrcount += ret;
 795
 796         ret = iio_device_add_info_mask_type(indio_dev, chan,
 797                                             IIO_SHARED_BY_ALL,
 798                                             &chan->info_mask_shared_by_all);
 799         if (ret < 0)
 800                 return ret;
 801         attrcount += ret;
 802
 803         if (chan->ext_info) {
 804                 unsigned int i = 0;
 805                 for (ext_info = chan->ext_info; ext_info->name; ext_info++) {
 806                         ret = __iio_add_chan_devattr(ext_info->name,
 807                                         chan,
 808                                         ext_info->read ?
 809                                             &iio_read_channel_ext_info : NULL,
 810                                         ext_info->write ?
 811                                             &iio_write_channel_ext_info : NULL,
 812                                         i,
 813                                         ext_info->shared,
 814                                         &indio_dev->dev,
 815                                         &indio_dev->channel_attr_list);
 816                         i++;
 817                         if (ret == -EBUSY && ext_info->shared)
 818                                 continue;
 819
 820                         if (ret)
 821                                 return ret;
 822
 823                         attrcount++;
 824                 }
 825         }
 826
 827         return attrcount;
 828 }
 829
 830 /**
 831  * iio_free_chan_devattr_list() - Free a list of IIO device attributes
 832  * @attr_list: List of IIO device attributes
 833  *
 834  * This function frees the memory allocated for each of the IIO device
 835  * attributes in the list. Note: if you want to reuse the list after calling
 836  * this function you have to reinitialize it using INIT_LIST_HEAD().
 837  */
 838 void iio_free_chan_devattr_list(struct list_head *attr_list)
 839 {
 840         struct iio_dev_attr *p, *n;
 841
 842         list_for_each_entry_safe(p, n, attr_list, l) {
 843                 kfree(p->dev_attr.attr.name);
 844                 kfree(p);
 845         }
 846 }
 847
 848 static ssize_t iio_show_dev_name(struct device *dev,
 849                                  struct device_attribute *attr,
 850                                  char *buf)
 851 {
 852         struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 853         return snprintf(buf, PAGE_SIZE, "%s\n", indio_dev->name);
 854 }
 855
 856 static DEVICE_ATTR(name, S_IRUGO, iio_show_dev_name, NULL);
 857
 858 static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 859 {
 860         int i, ret = 0, attrcount, attrn, attrcount_orig = 0;
 861         struct iio_dev_attr *p;
 862         struct attribute **attr;
 863
 864         /* First count elements in any existing group */
 865         if (indio_dev->info->attrs) {
 866                 attr = indio_dev->info->attrs->attrs;
 867                 while (*attr++ != NULL)
 868                         attrcount_orig++;
 869         }
 870         attrcount = attrcount_orig;
 871         /*
 872          * New channel registration method - relies on the fact a group does
 873          * not need to be initialized if its name is NULL.
 874          */
 875         if (indio_dev->channels)
 876                 for (i = 0; i < indio_dev->num_channels; i++) {
 877                         ret = iio_device_add_channel_sysfs(indio_dev,
 878                                                            &indio_dev
 879                                                            ->channels[i]);
 880                         if (ret < 0)
 881                                 goto error_clear_attrs;
 882                         attrcount += ret;
 883                 }
 884
 885         if (indio_dev->name)
 886                 attrcount++;
 887
 888         indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
 889                                                    sizeof(indio_dev->chan_attr_group.attrs[0]),
 890                                                    GFP_KERNEL);
 891         if (indio_dev->chan_attr_group.attrs == NULL) {
 892                 ret = -ENOMEM;
 893                 goto error_clear_attrs;
 894         }
 895         /* Copy across original attributes */
 896         if (indio_dev->info->attrs)
 897                 memcpy(indio_dev->chan_attr_group.attrs,
 898                        indio_dev->info->attrs->attrs,
 899                        sizeof(indio_dev->chan_attr_group.attrs[0])
 900                        *attrcount_orig);
 901         attrn = attrcount_orig;
 902         /* Add all elements from the list. */
 903         list_for_each_entry(p, &indio_dev->channel_attr_list, l)
 904                 indio_dev->chan_attr_group.attrs[attrn++] = &p->dev_attr.attr;
 905         if (indio_dev->name)
 906                 indio_dev->chan_attr_group.attrs[attrn++] = &dev_attr_name.attr;
 907
 908         indio_dev->groups[indio_dev->groupcounter++] =
 909                 &indio_dev->chan_attr_group;
 910
 911         return 0;
 912
 913 error_clear_attrs:
 914         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 915
 916         return ret;
 917 }
 918
 919 static void iio_device_unregister_sysfs(struct iio_dev *indio_dev)
 920 {
 921
 922         iio_free_chan_devattr_list(&indio_dev->channel_attr_list);
 923         kfree(indio_dev->chan_attr_group.attrs);
 924 }
 925
 926 static void iio_dev_release(struct device *device)
 927 {
 928         struct iio_dev *indio_dev = dev_to_iio_dev(device);
 929         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
 930                 iio_device_unregister_trigger_consumer(indio_dev);
 931         iio_device_unregister_eventset(indio_dev);
 932         iio_device_unregister_sysfs(indio_dev);
 933
 934         iio_buffer_put(indio_dev->buffer);
 935
 936         ida_simple_remove(&iio_ida, indio_dev->id);
 937         kfree(indio_dev);
 938 }
 939
 940 struct device_type iio_device_type = {
 941         .name = "iio_device",
 942         .release = iio_dev_release,
 943 };
 944
 945 /**
 946  * iio_device_alloc() - allocate an iio_dev from a driver
 947  * @sizeof_priv:        Space to allocate for private structure.
 948  **/
 949 struct iio_dev *iio_device_alloc(int sizeof_priv)
 950 {
 951         struct iio_dev *dev;
 952         size_t alloc_size;
 953
 954         alloc_size = sizeof(struct iio_dev);
 955         if (sizeof_priv) {
 956                 alloc_size = ALIGN(alloc_size, IIO_ALIGN);
 957                 alloc_size += sizeof_priv;
 958         }
 959         /* ensure 32-byte alignment of whole construct ? */
 960         alloc_size += IIO_ALIGN - 1;
 961
 962         dev = kzalloc(alloc_size, GFP_KERNEL);
 963
 964         if (dev) {
 965                 dev->dev.groups = dev->groups;
 966                 dev->dev.type = &iio_device_type;
 967                 dev->dev.bus = &iio_bus_type;
 968                 device_initialize(&dev->dev);
 969                 dev_set_drvdata(&dev->dev, (void *)dev);
 970                 mutex_init(&dev->mlock);
 971                 mutex_init(&dev->info_exist_lock);
 972                 INIT_LIST_HEAD(&dev->channel_attr_list);
 973
 974                 dev->id = ida_simple_get(&iio_ida, 0, 0, GFP_KERNEL);
 975                 if (dev->id < 0) {
 976                         /* cannot use a dev_err as the name isn't available */
 977                         pr_err("failed to get device id\n");
 978                         kfree(dev);
 979                         return NULL;
 980                 }
 981                 dev_set_name(&dev->dev, "iio:device%d", dev->id);
 982                 INIT_LIST_HEAD(&dev->buffer_list);
 983         }
 984
 985         return dev;
 986 }
 987 EXPORT_SYMBOL(iio_device_alloc);
 988
 989 /**
 990  * iio_device_free() - free an iio_dev from a driver
 991  * @dev:                the iio_dev associated with the device
 992  **/
 993 void iio_device_free(struct iio_dev *dev)
 994 {
 995         if (dev)
 996                 put_device(&dev->dev);
 997 }
 998 EXPORT_SYMBOL(iio_device_free);
 999
1000 static void devm_iio_device_release(struct device *dev, void *res)
1001 {
1002         iio_device_free(*(struct iio_dev **)res);
1003 }
1004
1005 static int devm_iio_device_match(struct device *dev, void *res, void *data)
1006 {
1007         struct iio_dev **r = res;
1008         if (!r || !*r) {
1009                 WARN_ON(!r || !*r);
1010                 return 0;
1011         }
1012         return *r == data;
1013 }
1014
1015 /**
1016  * devm_iio_device_alloc - Resource-managed iio_device_alloc()
1017  * @dev:                Device to allocate iio_dev for
1018  * @sizeof_priv:        Space to allocate for private structure.
1019  *
1020  * Managed iio_device_alloc. iio_dev allocated with this function is
1021  * automatically freed on driver detach.
1022  *
1023  * If an iio_dev allocated with this function needs to be freed separately,
1024  * devm_iio_device_free() must be used.
1025  *
1026  * RETURNS:
1027  * Pointer to allocated iio_dev on success, NULL on failure.
1028  */
1029 struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv)
1030 {
1031         struct iio_dev **ptr, *iio_dev;
1032
1033         ptr = devres_alloc(devm_iio_device_release, sizeof(*ptr),
1034                            GFP_KERNEL);
1035         if (!ptr)
1036                 return NULL;
1037
1038         /* use raw alloc_dr for kmalloc caller tracing */
1039         iio_dev = iio_device_alloc(sizeof_priv);
1040         if (iio_dev) {
1041                 *ptr = iio_dev;
1042                 devres_add(dev, ptr);
1043         } else {
1044                 devres_free(ptr);
1045         }
1046
1047         return iio_dev;
1048 }
1049 EXPORT_SYMBOL_GPL(devm_iio_device_alloc);
1050
1051 /**
1052  * devm_iio_device_free - Resource-managed iio_device_free()
1053  * @dev:                Device this iio_dev belongs to
1054  * @iio_dev:            the iio_dev associated with the device
1055  *
1056  * Free iio_dev allocated with devm_iio_device_alloc().
1057  */
1058 void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev)
1059 {
1060         int rc;
1061
1062         rc = devres_release(dev, devm_iio_device_release,
1063                             devm_iio_device_match, iio_dev);
1064         WARN_ON(rc);
1065 }
1066 EXPORT_SYMBOL_GPL(devm_iio_device_free);
1067
1068 /**
1069  * iio_chrdev_open() - chrdev file open for buffer access and ioctls
1070  **/
1071 static int iio_chrdev_open(struct inode *inode, struct file *filp)
1072 {
1073         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1074                                                 struct iio_dev, chrdev);
1075
1076         if (test_and_set_bit(IIO_BUSY_BIT_POS, &indio_dev->flags))
1077                 return -EBUSY;
1078
1079         iio_device_get(indio_dev);
1080
1081         filp->private_data = indio_dev;
1082
1083         return 0;
1084 }
1085
1086 /**
1087  * iio_chrdev_release() - chrdev file close buffer access and ioctls
1088  **/
1089 static int iio_chrdev_release(struct inode *inode, struct file *filp)
1090 {
1091         struct iio_dev *indio_dev = container_of(inode->i_cdev,
1092                                                 struct iio_dev, chrdev);
1093         clear_bit(IIO_BUSY_BIT_POS, &indio_dev->flags);
1094         iio_device_put(indio_dev);
1095
1096         return 0;
1097 }
1098
1099 /* Somewhat of a cross file organization violation - ioctls here are actually
1100  * event related */
1101 static long iio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1102 {
1103         struct iio_dev *indio_dev = filp->private_data;
1104         int __user *ip = (int __user *)arg;
1105         int fd;
1106
1107         if (!indio_dev->info)
1108                 return -ENODEV;
1109
1110         if (cmd == IIO_GET_EVENT_FD_IOCTL) {
1111                 fd = iio_event_getfd(indio_dev);
1112                 if (copy_to_user(ip, &fd, sizeof(fd)))
1113                         return -EFAULT;
1114                 return 0;
1115         }
1116         return -EINVAL;
1117 }
1118
1119 static const struct file_operations iio_buffer_fileops = {
1120         .read = iio_buffer_read_first_n_outer_addr,
1121         .release = iio_chrdev_release,
1122         .open = iio_chrdev_open,
1123         .poll = iio_buffer_poll_addr,
1124         .owner = THIS_MODULE,
1125         .llseek = noop_llseek,
1126         .unlocked_ioctl = iio_ioctl,
1127         .compat_ioctl = iio_ioctl,
1128 };
1129
1130 static const struct iio_buffer_setup_ops noop_ring_setup_ops;
1131
1132 /**
1133  * iio_device_register() - register a device with the IIO subsystem
1134  * @indio_dev:          Device structure filled by the device driver
1135  **/
1136 int iio_device_register(struct iio_dev *indio_dev)
1137 {
1138         int ret;
1139
1140         /* If the calling driver did not initialize of_node, do it here */
1141         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
1142                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
1143
1144         /* configure elements for the chrdev */
1145         indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id);
1146
1147         ret = iio_device_register_debugfs(indio_dev);
1148         if (ret) {
1149                 dev_err(indio_dev->dev.parent,
1150                         "Failed to register debugfs interfaces\n");
1151                 return ret;
1152         }
1153         ret = iio_device_register_sysfs(indio_dev);
1154         if (ret) {
1155                 dev_err(indio_dev->dev.parent,
1156                         "Failed to register sysfs interfaces\n");
1157                 goto error_unreg_debugfs;
1158         }
1159         ret = iio_device_register_eventset(indio_dev);
1160         if (ret) {
1161                 dev_err(indio_dev->dev.parent,
1162                         "Failed to register event set\n");
1163                 goto error_free_sysfs;
1164         }
1165         if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
1166                 iio_device_register_trigger_consumer(indio_dev);
1167
1168         if ((indio_dev->modes & INDIO_ALL_BUFFER_MODES) &&
1169                 indio_dev->setup_ops == NULL)
1170                 indio_dev->setup_ops = &noop_ring_setup_ops;
1171
1172         cdev_init(&indio_dev->chrdev, &iio_buffer_fileops);
1173         indio_dev->chrdev.owner = indio_dev->info->driver_module;
1174         indio_dev->chrdev.kobj.parent = &indio_dev->dev.kobj;
1175         ret = cdev_add(&indio_dev->chrdev, indio_dev->dev.devt, 1);
1176         if (ret < 0)
1177                 goto error_unreg_eventset;
1178
1179         ret = device_add(&indio_dev->dev);
1180         if (ret < 0)
1181                 goto error_cdev_del;
1182
1183         return 0;
1184 error_cdev_del:
1185         cdev_del(&indio_dev->chrdev);
1186 error_unreg_eventset:
1187         iio_device_unregister_eventset(indio_dev);
1188 error_free_sysfs:
1189         iio_device_unregister_sysfs(indio_dev);
1190 error_unreg_debugfs:
1191         iio_device_unregister_debugfs(indio_dev);
1192         return ret;
1193 }
1194 EXPORT_SYMBOL(iio_device_register);
1195
1196 /**
1197  * iio_device_unregister() - unregister a device from the IIO subsystem
1198  * @indio_dev:          Device structure representing the device.
1199  **/
1200 void iio_device_unregister(struct iio_dev *indio_dev)
1201 {
1202         mutex_lock(&indio_dev->info_exist_lock);
1203
1204         device_del(&indio_dev->dev);
1205
1206         if (indio_dev->chrdev.dev)
1207                 cdev_del(&indio_dev->chrdev);
1208         iio_device_unregister_debugfs(indio_dev);
1209
1210         iio_disable_all_buffers(indio_dev);
1211
1212         indio_dev->info = NULL;
1213
1214         iio_device_wakeup_eventset(indio_dev);
1215         iio_buffer_wakeup_poll(indio_dev);
1216
1217         mutex_unlock(&indio_dev->info_exist_lock);
1218 }
1219 EXPORT_SYMBOL(iio_device_unregister);
1220
1221 static void devm_iio_device_unreg(struct device *dev, void *res)
1222 {
1223         iio_device_unregister(*(struct iio_dev **)res);
1224 }
1225
1226 /**
1227  * devm_iio_device_register - Resource-managed iio_device_register()
1228  * @dev:        Device to allocate iio_dev for
1229  * @indio_dev:  Device structure filled by the device driver
1230  *
1231  * Managed iio_device_register.  The IIO device registered with this
1232  * function is automatically unregistered on driver detach. This function
1233  * calls iio_device_register() internally. Refer to that function for more
1234  * information.
1235  *
1236  * If an iio_dev registered with this function needs to be unregistered
1237  * separately, devm_iio_device_unregister() must be used.
1238  *
1239  * RETURNS:
1240  * 0 on success, negative error number on failure.
1241  */
1242 int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev)
1243 {
1244         struct iio_dev **ptr;
1245         int ret;
1246
1247         ptr = devres_alloc(devm_iio_device_unreg, sizeof(*ptr), GFP_KERNEL);
1248         if (!ptr)
1249                 return -ENOMEM;
1250
1251         *ptr = indio_dev;
1252         ret = iio_device_register(indio_dev);
1253         if (!ret)
1254                 devres_add(dev, ptr);
1255         else
1256                 devres_free(ptr);
1257
1258         return ret;
1259 }
1260 EXPORT_SYMBOL_GPL(devm_iio_device_register);
1261
1262 /**
1263  * devm_iio_device_unregister - Resource-managed iio_device_unregister()
1264  * @dev:        Device this iio_dev belongs to
1265  * @indio_dev:  the iio_dev associated with the device
1266  *
1267  * Unregister iio_dev registered with devm_iio_device_register().
1268  */
1269 void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev)
1270 {
1271         int rc;
1272
1273         rc = devres_release(dev, devm_iio_device_unreg,
1274                             devm_iio_device_match, indio_dev);
1275         WARN_ON(rc);
1276 }
1277 EXPORT_SYMBOL_GPL(devm_iio_device_unregister);
1278
1279 subsys_initcall(iio_init);
1280 module_exit(iio_exit);
1281
1282 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
1283 MODULE_DESCRIPTION("Industrial I/O core");
1284 MODULE_LICENSE("GPL");