drivers/staging/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 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/idr.h>
  15 #include <linux/kdev_t.h>
  16 #include <linux/err.h>
  17 #include <linux/device.h>
  18 #include <linux/fs.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/poll.h>
  21 #include <linux/sched.h>
  22 #include <linux/wait.h>
  23 #include <linux/cdev.h>
  24 #include <linux/slab.h>
  25 #include "iio.h"
  26 #include "trigger_consumer.h"
  27
  28 #define IIO_ID_PREFIX "device"
  29 #define IIO_ID_FORMAT IIO_ID_PREFIX "%d"
  30
  31 /* IDR to assign each registered device a unique id*/
  32 static DEFINE_IDA(iio_ida);
  33 /* IDR to allocate character device minor numbers */
  34 static DEFINE_IDA(iio_chrdev_ida);
  35 /* Lock used to protect both of the above */
  36 static DEFINE_SPINLOCK(iio_ida_lock);
  37
  38 dev_t iio_devt;
  39 EXPORT_SYMBOL(iio_devt);
  40
  41 #define IIO_DEV_MAX 256
  42 struct bus_type iio_bus_type = {
  43         .name = "iio",
  44 };
  45 EXPORT_SYMBOL(iio_bus_type);
  46
  47 void __iio_change_event(struct iio_detected_event_list *ev,
  48                         int ev_code,
  49                         s64 timestamp)
  50 {
  51         ev->ev.id = ev_code;
  52         ev->ev.timestamp = timestamp;
  53 }
  54 EXPORT_SYMBOL(__iio_change_event);
  55
  56 /* Used both in the interrupt line put events and the ring buffer ones */
  57
  58 /* Note that in it's current form someone has to be listening before events
  59  * are queued. Hence a client MUST open the chrdev before the ring buffer is
  60  * switched on.
  61  */
  62 int __iio_push_event(struct iio_event_interface *ev_int,
  63                      int ev_code,
  64                      s64 timestamp,
  65                      struct iio_shared_ev_pointer *
  66                      shared_pointer_p)
  67 {
  68         struct iio_detected_event_list *ev;
  69         int ret = 0;
  70
  71         /* Does anyone care? */
  72         mutex_lock(&ev_int->event_list_lock);
  73         if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) {
  74                 if (ev_int->current_events == ev_int->max_events) {
  75                         mutex_unlock(&ev_int->event_list_lock);
  76                         return 0;
  77                 }
  78                 ev = kmalloc(sizeof(*ev), GFP_KERNEL);
  79                 if (ev == NULL) {
  80                         ret = -ENOMEM;
  81                         mutex_unlock(&ev_int->event_list_lock);
  82                         goto error_ret;
  83                 }
  84                 ev->ev.id = ev_code;
  85                 ev->ev.timestamp = timestamp;
  86                 ev->shared_pointer = shared_pointer_p;
  87                 if (ev->shared_pointer)
  88                         shared_pointer_p->ev_p = ev;
  89
  90                 list_add_tail(&ev->list, &ev_int->det_events.list);
  91                 ev_int->current_events++;
  92                 mutex_unlock(&ev_int->event_list_lock);
  93                 wake_up_interruptible(&ev_int->wait);
  94         } else
  95                 mutex_unlock(&ev_int->event_list_lock);
  96
  97 error_ret:
  98         return ret;
  99 }
 100 EXPORT_SYMBOL(__iio_push_event);
 101
 102 int iio_push_event(struct iio_dev *dev_info,
 103                    int ev_line,
 104                    int ev_code,
 105                    s64 timestamp)
 106 {
 107         return __iio_push_event(&dev_info->event_interfaces[ev_line],
 108                                 ev_code, timestamp, NULL);
 109 }
 110 EXPORT_SYMBOL(iio_push_event);
 111
 112 /* Generic interrupt line interrupt handler */
 113 static irqreturn_t iio_interrupt_handler(int irq, void *_int_info)
 114 {
 115         struct iio_interrupt *int_info = _int_info;
 116         struct iio_dev *dev_info = int_info->dev_info;
 117         struct iio_event_handler_list *p;
 118         s64 time_ns;
 119         unsigned long flags;
 120
 121         spin_lock_irqsave(&int_info->ev_list_lock, flags);
 122         if (list_empty(&int_info->ev_list)) {
 123                 spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 124                 return IRQ_NONE;
 125         }
 126
 127         time_ns = iio_get_time_ns();
 128         list_for_each_entry(p, &int_info->ev_list, list) {
 129                 disable_irq_nosync(irq);
 130                 p->handler(dev_info, 1, time_ns, !(p->refcount > 1));
 131         }
 132         spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 133
 134         return IRQ_HANDLED;
 135 }
 136
 137 static struct iio_interrupt *iio_allocate_interrupt(void)
 138 {
 139         struct iio_interrupt *i = kmalloc(sizeof *i, GFP_KERNEL);
 140         if (i) {
 141                 spin_lock_init(&i->ev_list_lock);
 142                 INIT_LIST_HEAD(&i->ev_list);
 143         }
 144         return i;
 145 }
 146
 147 /* Confirming the validity of supplied irq is left to drivers.*/
 148 int iio_register_interrupt_line(unsigned int irq,
 149                                 struct iio_dev *dev_info,
 150                                 int line_number,
 151                                 unsigned long type,
 152                                 const char *name)
 153 {
 154         int ret;
 155
 156         dev_info->interrupts[line_number] = iio_allocate_interrupt();
 157         if (dev_info->interrupts[line_number] == NULL) {
 158                 ret = -ENOMEM;
 159                 goto error_ret;
 160         }
 161         dev_info->interrupts[line_number]->line_number = line_number;
 162         dev_info->interrupts[line_number]->irq = irq;
 163         dev_info->interrupts[line_number]->dev_info = dev_info;
 164
 165         /* Possibly only request on demand?
 166          * Can see this may complicate the handling of interrupts.
 167          * However, with this approach we might end up handling lots of
 168          * events no-one cares about.*/
 169         ret = request_irq(irq,
 170                           &iio_interrupt_handler,
 171                           type,
 172                           name,
 173                           dev_info->interrupts[line_number]);
 174
 175 error_ret:
 176         return ret;
 177 }
 178 EXPORT_SYMBOL(iio_register_interrupt_line);
 179
 180 /* This turns up an awful lot */
 181 ssize_t iio_read_const_attr(struct device *dev,
 182                             struct device_attribute *attr,
 183                             char *buf)
 184 {
 185         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 186 }
 187 EXPORT_SYMBOL(iio_read_const_attr);
 188
 189 /* Before this runs the interrupt generator must have been disabled */
 190 void iio_unregister_interrupt_line(struct iio_dev *dev_info, int line_number)
 191 {
 192         /* make sure the interrupt handlers are all done */
 193         flush_scheduled_work();
 194         free_irq(dev_info->interrupts[line_number]->irq,
 195                  dev_info->interrupts[line_number]);
 196         kfree(dev_info->interrupts[line_number]);
 197 }
 198 EXPORT_SYMBOL(iio_unregister_interrupt_line);
 199
 200 /* Reference counted add and remove */
 201 void iio_add_event_to_list(struct iio_event_handler_list *el,
 202                           struct list_head *head)
 203 {
 204         unsigned long flags;
 205         struct iio_interrupt *inter = to_iio_interrupt(head);
 206
 207         /* take mutex to protect this element */
 208         mutex_lock(&el->exist_lock);
 209         if (el->refcount == 0) {
 210                 /* Take the event list spin lock */
 211                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 212                 list_add(&el->list, head);
 213                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 214         }
 215         el->refcount++;
 216         mutex_unlock(&el->exist_lock);
 217 }
 218 EXPORT_SYMBOL(iio_add_event_to_list);
 219
 220 void iio_remove_event_from_list(struct iio_event_handler_list *el,
 221                                struct list_head *head)
 222 {
 223         unsigned long flags;
 224         struct iio_interrupt *inter = to_iio_interrupt(head);
 225
 226         mutex_lock(&el->exist_lock);
 227         el->refcount--;
 228         if (el->refcount == 0) {
 229                 /* Take the event list spin lock */
 230                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 231                 list_del_init(&el->list);
 232                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 233         }
 234         mutex_unlock(&el->exist_lock);
 235 }
 236 EXPORT_SYMBOL(iio_remove_event_from_list);
 237
 238 static ssize_t iio_event_chrdev_read(struct file *filep,
 239                                      char __user *buf,
 240                                      size_t count,
 241                                      loff_t *f_ps)
 242 {
 243         struct iio_event_interface *ev_int = filep->private_data;
 244         struct iio_detected_event_list *el;
 245         int ret;
 246         size_t len;
 247
 248         mutex_lock(&ev_int->event_list_lock);
 249         if (list_empty(&ev_int->det_events.list)) {
 250                 if (filep->f_flags & O_NONBLOCK) {
 251                         ret = -EAGAIN;
 252                         goto error_mutex_unlock;
 253                 }
 254                 mutex_unlock(&ev_int->event_list_lock);
 255                 /* Blocking on device; waiting for something to be there */
 256                 ret = wait_event_interruptible(ev_int->wait,
 257                                                !list_empty(&ev_int
 258                                                            ->det_events.list));
 259                 if (ret)
 260                         goto error_ret;
 261                 /* Single access device so noone else can get the data */
 262                 mutex_lock(&ev_int->event_list_lock);
 263         }
 264
 265         el = list_first_entry(&ev_int->det_events.list,
 266                               struct iio_detected_event_list,
 267                               list);
 268         len = sizeof el->ev;
 269         if (copy_to_user(buf, &(el->ev), len)) {
 270                 ret = -EFAULT;
 271                 goto error_mutex_unlock;
 272         }
 273         list_del(&el->list);
 274         ev_int->current_events--;
 275         mutex_unlock(&ev_int->event_list_lock);
 276         /*
 277          * Possible concurency issue if an update of this event is on its way
 278          * through. May lead to new event being removed whilst the reported
 279          * event was the unescalated event. In typical use case this is not a
 280          * problem as userspace will say read half the buffer due to a 50%
 281          * full event which would make the correct 100% full incorrect anyway.
 282          */
 283         if (el->shared_pointer) {
 284                 spin_lock(&el->shared_pointer->lock);
 285                 (el->shared_pointer->ev_p) = NULL;
 286                 spin_unlock(&el->shared_pointer->lock);
 287         }
 288         kfree(el);
 289
 290         return len;
 291
 292 error_mutex_unlock:
 293         mutex_unlock(&ev_int->event_list_lock);
 294 error_ret:
 295
 296         return ret;
 297 }
 298
 299 static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 300 {
 301         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 302         struct iio_event_interface *ev_int = hand->private;
 303         struct iio_detected_event_list *el, *t;
 304
 305         mutex_lock(&ev_int->event_list_lock);
 306         clear_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags);
 307         /*
 308          * In order to maintain a clean state for reopening,
 309          * clear out any awaiting events. The mask will prevent
 310          * any new __iio_push_event calls running.
 311          */
 312         list_for_each_entry_safe(el, t, &ev_int->det_events.list, list) {
 313                 list_del(&el->list);
 314                 kfree(el);
 315         }
 316         mutex_unlock(&ev_int->event_list_lock);
 317
 318         return 0;
 319 }
 320
 321 static int iio_event_chrdev_open(struct inode *inode, struct file *filep)
 322 {
 323         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 324         struct iio_event_interface *ev_int = hand->private;
 325
 326         mutex_lock(&ev_int->event_list_lock);
 327         if (test_and_set_bit(IIO_BUSY_BIT_POS, &hand->flags)) {
 328                 fops_put(filep->f_op);
 329                 mutex_unlock(&ev_int->event_list_lock);
 330                 return -EBUSY;
 331         }
 332         filep->private_data = hand->private;
 333         mutex_unlock(&ev_int->event_list_lock);
 334
 335         return 0;
 336 }
 337
 338 static const struct file_operations iio_event_chrdev_fileops = {
 339         .read =  iio_event_chrdev_read,
 340         .release = iio_event_chrdev_release,
 341         .open = iio_event_chrdev_open,
 342         .owner = THIS_MODULE,
 343         .llseek = noop_llseek,
 344 };
 345
 346 static void iio_event_dev_release(struct device *dev)
 347 {
 348         struct iio_event_interface *ev_int
 349                 = container_of(dev, struct iio_event_interface, dev);
 350         cdev_del(&ev_int->handler.chrdev);
 351         iio_device_free_chrdev_minor(MINOR(dev->devt));
 352 };
 353
 354 static struct device_type iio_event_type = {
 355         .release = iio_event_dev_release,
 356 };
 357
 358 int iio_device_get_chrdev_minor(void)
 359 {
 360         int ret, val;
 361
 362 ida_again:
 363         if (unlikely(ida_pre_get(&iio_chrdev_ida, GFP_KERNEL) == 0))
 364                 return -ENOMEM;
 365         spin_lock(&iio_ida_lock);
 366         ret = ida_get_new(&iio_chrdev_ida, &val);
 367         spin_unlock(&iio_ida_lock);
 368         if (unlikely(ret == -EAGAIN))
 369                 goto ida_again;
 370         else if (unlikely(ret))
 371                 return ret;
 372         if (val > IIO_DEV_MAX)
 373                 return -ENOMEM;
 374         return val;
 375 }
 376
 377 void iio_device_free_chrdev_minor(int val)
 378 {
 379         spin_lock(&iio_ida_lock);
 380         ida_remove(&iio_chrdev_ida, val);
 381         spin_unlock(&iio_ida_lock);
 382 }
 383
 384 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 385                      const char *name,
 386                      struct module *owner,
 387                      struct device *dev)
 388 {
 389         int ret, minor;
 390
 391         ev_int->dev.bus = &iio_bus_type;
 392         ev_int->dev.parent = dev;
 393         ev_int->dev.type = &iio_event_type;
 394         device_initialize(&ev_int->dev);
 395
 396         minor = iio_device_get_chrdev_minor();
 397         if (minor < 0) {
 398                 ret = minor;
 399                 goto error_device_put;
 400         }
 401         ev_int->dev.devt = MKDEV(MAJOR(iio_devt), minor);
 402         dev_set_name(&ev_int->dev, "%s", name);
 403
 404         ret = device_add(&ev_int->dev);
 405         if (ret)
 406                 goto error_free_minor;
 407
 408         cdev_init(&ev_int->handler.chrdev, &iio_event_chrdev_fileops);
 409         ev_int->handler.chrdev.owner = owner;
 410
 411         mutex_init(&ev_int->event_list_lock);
 412         /* discussion point - make this variable? */
 413         ev_int->max_events = 10;
 414         ev_int->current_events = 0;
 415         INIT_LIST_HEAD(&ev_int->det_events.list);
 416         init_waitqueue_head(&ev_int->wait);
 417         ev_int->handler.private = ev_int;
 418         ev_int->handler.flags = 0;
 419
 420         ret = cdev_add(&ev_int->handler.chrdev, ev_int->dev.devt, 1);
 421         if (ret)
 422                 goto error_unreg_device;
 423
 424         return 0;
 425
 426 error_unreg_device:
 427         device_unregister(&ev_int->dev);
 428 error_free_minor:
 429         iio_device_free_chrdev_minor(minor);
 430 error_device_put:
 431         put_device(&ev_int->dev);
 432
 433         return ret;
 434 }
 435
 436 void iio_free_ev_int(struct iio_event_interface *ev_int)
 437 {
 438         device_unregister(&ev_int->dev);
 439         put_device(&ev_int->dev);
 440 }
 441
 442 static int __init iio_dev_init(void)
 443 {
 444         int err;
 445
 446         err = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 447         if (err < 0)
 448                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 449                        __FILE__);
 450
 451         return err;
 452 }
 453
 454 static void __exit iio_dev_exit(void)
 455 {
 456         if (iio_devt)
 457                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 458 }
 459
 460 static int __init iio_init(void)
 461 {
 462         int ret;
 463
 464         /* Register sysfs bus */
 465         ret  = bus_register(&iio_bus_type);
 466         if (ret < 0) {
 467                 printk(KERN_ERR
 468                        "%s could not register bus type\n",
 469                         __FILE__);
 470                 goto error_nothing;
 471         }
 472
 473         ret = iio_dev_init();
 474         if (ret < 0)
 475                 goto error_unregister_bus_type;
 476
 477         return 0;
 478
 479 error_unregister_bus_type:
 480         bus_unregister(&iio_bus_type);
 481 error_nothing:
 482         return ret;
 483 }
 484
 485 static void __exit iio_exit(void)
 486 {
 487         iio_dev_exit();
 488         bus_unregister(&iio_bus_type);
 489 }
 490
 491 static int iio_device_register_sysfs(struct iio_dev *dev_info)
 492 {
 493         int ret = 0;
 494
 495         ret = sysfs_create_group(&dev_info->dev.kobj, dev_info->attrs);
 496         if (ret) {
 497                 dev_err(dev_info->dev.parent,
 498                         "Failed to register sysfs hooks\n");
 499                 goto error_ret;
 500         }
 501
 502 error_ret:
 503         return ret;
 504 }
 505
 506 static void iio_device_unregister_sysfs(struct iio_dev *dev_info)
 507 {
 508         sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
 509 }
 510
 511 /* Return a negative errno on failure */
 512 int iio_get_new_ida_val(struct ida *this_ida)
 513 {
 514         int ret;
 515         int val;
 516
 517 ida_again:
 518         if (unlikely(ida_pre_get(this_ida, GFP_KERNEL) == 0))
 519                 return -ENOMEM;
 520
 521         spin_lock(&iio_ida_lock);
 522         ret = ida_get_new(this_ida, &val);
 523         spin_unlock(&iio_ida_lock);
 524         if (unlikely(ret == -EAGAIN))
 525                 goto ida_again;
 526         else if (unlikely(ret))
 527                 return ret;
 528
 529         return val;
 530 }
 531 EXPORT_SYMBOL(iio_get_new_ida_val);
 532
 533 void iio_free_ida_val(struct ida *this_ida, int id)
 534 {
 535         spin_lock(&iio_ida_lock);
 536         ida_remove(this_ida, id);
 537         spin_unlock(&iio_ida_lock);
 538 }
 539 EXPORT_SYMBOL(iio_free_ida_val);
 540
 541 static int iio_device_register_id(struct iio_dev *dev_info,
 542                                   struct ida *this_ida)
 543 {
 544         dev_info->id = iio_get_new_ida_val(&iio_ida);
 545         if (dev_info->id < 0)
 546                 return dev_info->id;
 547         return 0;
 548 }
 549
 550 static void iio_device_unregister_id(struct iio_dev *dev_info)
 551 {
 552         iio_free_ida_val(&iio_ida, dev_info->id);
 553 }
 554
 555 static inline int __iio_add_event_config_attrs(struct iio_dev *dev_info, int i)
 556 {
 557         int ret;
 558         /*p for adding, q for removing */
 559         struct attribute **attrp, **attrq;
 560
 561         if (dev_info->event_conf_attrs && dev_info->event_conf_attrs[i].attrs) {
 562                 attrp = dev_info->event_conf_attrs[i].attrs;
 563                 while (*attrp) {
 564                         ret =  sysfs_add_file_to_group(&dev_info->dev.kobj,
 565                                                        *attrp,
 566                                                        dev_info
 567                                                        ->event_attrs[i].name);
 568                         if (ret)
 569                                 goto error_ret;
 570                         attrp++;
 571                 }
 572         }
 573         return 0;
 574
 575 error_ret:
 576         attrq = dev_info->event_conf_attrs[i].attrs;
 577         while (attrq != attrp) {
 578                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 579                                              *attrq,
 580                                              dev_info->event_attrs[i].name);
 581                 attrq++;
 582         }
 583
 584         return ret;
 585 }
 586
 587 static inline int __iio_remove_event_config_attrs(struct iio_dev *dev_info,
 588                                                   int i)
 589 {
 590         struct attribute **attrq;
 591
 592         if (dev_info->event_conf_attrs
 593                 && dev_info->event_conf_attrs[i].attrs) {
 594                 attrq = dev_info->event_conf_attrs[i].attrs;
 595                 while (*attrq) {
 596                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 597                                                      *attrq,
 598                                                      dev_info
 599                                                      ->event_attrs[i].name);
 600                         attrq++;
 601                 }
 602         }
 603
 604         return 0;
 605 }
 606
 607 static int iio_device_register_eventset(struct iio_dev *dev_info)
 608 {
 609         int ret = 0, i, j;
 610
 611         if (dev_info->num_interrupt_lines == 0)
 612                 return 0;
 613
 614         dev_info->event_interfaces =
 615                 kzalloc(sizeof(struct iio_event_interface)
 616                         *dev_info->num_interrupt_lines,
 617                         GFP_KERNEL);
 618         if (dev_info->event_interfaces == NULL) {
 619                 ret = -ENOMEM;
 620                 goto error_ret;
 621         }
 622
 623         dev_info->interrupts = kzalloc(sizeof(struct iio_interrupt *)
 624                                        *dev_info->num_interrupt_lines,
 625                                        GFP_KERNEL);
 626         if (dev_info->interrupts == NULL) {
 627                 ret = -ENOMEM;
 628                 goto error_free_event_interfaces;
 629         }
 630
 631         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 632                 dev_info->event_interfaces[i].owner = dev_info->driver_module;
 633
 634                 snprintf(dev_info->event_interfaces[i]._name, 20,
 635                          "%s:event%d",
 636                          dev_name(&dev_info->dev),
 637                          i);
 638
 639                 ret = iio_setup_ev_int(&dev_info->event_interfaces[i],
 640                                        (const char *)(dev_info
 641                                                       ->event_interfaces[i]
 642                                                       ._name),
 643                                        dev_info->driver_module,
 644                                        &dev_info->dev);
 645                 if (ret) {
 646                         dev_err(&dev_info->dev,
 647                                 "Could not get chrdev interface\n");
 648                         goto error_free_setup_ev_ints;
 649                 }
 650
 651                 dev_set_drvdata(&dev_info->event_interfaces[i].dev,
 652                                 (void *)dev_info);
 653                 ret = sysfs_create_group(&dev_info
 654                                         ->event_interfaces[i]
 655                                         .dev.kobj,
 656                                         &dev_info->event_attrs[i]);
 657
 658                 if (ret) {
 659                         dev_err(&dev_info->dev,
 660                                 "Failed to register sysfs for event attrs");
 661                         goto error_remove_sysfs_interfaces;
 662                 }
 663         }
 664
 665         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 666                 ret = __iio_add_event_config_attrs(dev_info, i);
 667                 if (ret)
 668                         goto error_unregister_config_attrs;
 669         }
 670
 671         return 0;
 672
 673 error_unregister_config_attrs:
 674         for (j = 0; j < i; j++)
 675                 __iio_remove_event_config_attrs(dev_info, i);
 676         i = dev_info->num_interrupt_lines - 1;
 677 error_remove_sysfs_interfaces:
 678         for (j = 0; j < i; j++)
 679                 sysfs_remove_group(&dev_info
 680                                    ->event_interfaces[j].dev.kobj,
 681                                    &dev_info->event_attrs[j]);
 682 error_free_setup_ev_ints:
 683         for (j = 0; j < i; j++)
 684                 iio_free_ev_int(&dev_info->event_interfaces[j]);
 685         kfree(dev_info->interrupts);
 686 error_free_event_interfaces:
 687         kfree(dev_info->event_interfaces);
 688 error_ret:
 689
 690         return ret;
 691 }
 692
 693 static void iio_device_unregister_eventset(struct iio_dev *dev_info)
 694 {
 695         int i;
 696
 697         if (dev_info->num_interrupt_lines == 0)
 698                 return;
 699         for (i = 0; i < dev_info->num_interrupt_lines; i++)
 700                 sysfs_remove_group(&dev_info
 701                                    ->event_interfaces[i].dev.kobj,
 702                                    &dev_info->event_attrs[i]);
 703
 704         for (i = 0; i < dev_info->num_interrupt_lines; i++)
 705                 iio_free_ev_int(&dev_info->event_interfaces[i]);
 706         kfree(dev_info->interrupts);
 707         kfree(dev_info->event_interfaces);
 708 }
 709
 710 static void iio_dev_release(struct device *device)
 711 {
 712         struct iio_dev *dev = to_iio_dev(device);
 713
 714         iio_put();
 715         kfree(dev);
 716 }
 717
 718 static struct device_type iio_dev_type = {
 719         .name = "iio_device",
 720         .release = iio_dev_release,
 721 };
 722
 723 struct iio_dev *iio_allocate_device(void)
 724 {
 725         struct iio_dev *dev = kzalloc(sizeof *dev, GFP_KERNEL);
 726
 727         if (dev) {
 728                 dev->dev.type = &iio_dev_type;
 729                 dev->dev.bus = &iio_bus_type;
 730                 device_initialize(&dev->dev);
 731                 dev_set_drvdata(&dev->dev, (void *)dev);
 732                 mutex_init(&dev->mlock);
 733                 iio_get();
 734         }
 735
 736         return dev;
 737 }
 738 EXPORT_SYMBOL(iio_allocate_device);
 739
 740 void iio_free_device(struct iio_dev *dev)
 741 {
 742         if (dev)
 743                 iio_put_device(dev);
 744 }
 745 EXPORT_SYMBOL(iio_free_device);
 746
 747 int iio_device_register(struct iio_dev *dev_info)
 748 {
 749         int ret;
 750
 751         ret = iio_device_register_id(dev_info, &iio_ida);
 752         if (ret) {
 753                 dev_err(&dev_info->dev, "Failed to get id\n");
 754                 goto error_ret;
 755         }
 756         dev_set_name(&dev_info->dev, "device%d", dev_info->id);
 757
 758         ret = device_add(&dev_info->dev);
 759         if (ret)
 760                 goto error_free_ida;
 761         ret = iio_device_register_sysfs(dev_info);
 762         if (ret) {
 763                 dev_err(dev_info->dev.parent,
 764                         "Failed to register sysfs interfaces\n");
 765                 goto error_del_device;
 766         }
 767         ret = iio_device_register_eventset(dev_info);
 768         if (ret) {
 769                 dev_err(dev_info->dev.parent,
 770                         "Failed to register event set\n");
 771                 goto error_free_sysfs;
 772         }
 773         if (dev_info->modes & INDIO_RING_TRIGGERED)
 774                 iio_device_register_trigger_consumer(dev_info);
 775
 776         return 0;
 777
 778 error_free_sysfs:
 779         iio_device_unregister_sysfs(dev_info);
 780 error_del_device:
 781         device_del(&dev_info->dev);
 782 error_free_ida:
 783         iio_device_unregister_id(dev_info);
 784 error_ret:
 785         return ret;
 786 }
 787 EXPORT_SYMBOL(iio_device_register);
 788
 789 void iio_device_unregister(struct iio_dev *dev_info)
 790 {
 791         if (dev_info->modes & INDIO_RING_TRIGGERED)
 792                 iio_device_unregister_trigger_consumer(dev_info);
 793         iio_device_unregister_eventset(dev_info);
 794         iio_device_unregister_sysfs(dev_info);
 795         iio_device_unregister_id(dev_info);
 796         device_unregister(&dev_info->dev);
 797 }
 798 EXPORT_SYMBOL(iio_device_unregister);
 799
 800 void iio_put(void)
 801 {
 802         module_put(THIS_MODULE);
 803 }
 804
 805 void iio_get(void)
 806 {
 807         __module_get(THIS_MODULE);
 808 }
 809
 810 subsys_initcall(iio_init);
 811 module_exit(iio_exit);
 812
 813 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 814 MODULE_DESCRIPTION("Industrial I/O core");
 815 MODULE_LICENSE("GPL");