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 "iio.h"
  25 #include "trigger_consumer.h"
  26
  27 #define IIO_ID_PREFIX "device"
  28 #define IIO_ID_FORMAT IIO_ID_PREFIX "%d"
  29
  30 /* IDR to assign each registered device a unique id*/
  31 static DEFINE_IDR(iio_idr);
  32
  33 /* IDR for general event identifiers */
  34 static DEFINE_IDR(iio_event_idr);
  35 /* IDR to allocate character device minor numbers */
  36 static DEFINE_IDR(iio_chrdev_idr);
  37 /* Lock used to protect both of the above */
  38 static DEFINE_SPINLOCK(iio_idr_lock);
  39
  40 dev_t iio_devt;
  41 EXPORT_SYMBOL(iio_devt);
  42
  43 #define IIO_DEV_MAX 256
  44 static char *iio_devnode(struct device *dev, mode_t *mode)
  45 {
  46         return kasprintf(GFP_KERNEL, "iio/%s", dev_name(dev));
  47 }
  48
  49 struct class iio_class = {
  50         .name = "iio",
  51         .devnode = iio_devnode,
  52 };
  53 EXPORT_SYMBOL(iio_class);
  54
  55 void __iio_change_event(struct iio_detected_event_list *ev,
  56                         int ev_code,
  57                         s64 timestamp)
  58 {
  59         ev->ev.id = ev_code;
  60         ev->ev.timestamp = timestamp;
  61 }
  62 EXPORT_SYMBOL(__iio_change_event);
  63
  64 /* Used both in the interrupt line put events and the ring buffer ones */
  65
  66 /* Note that in it's current form someone has to be listening before events
  67  * are queued. Hence a client MUST open the chrdev before the ring buffer is
  68  * switched on.
  69  */
  70  int __iio_push_event(struct iio_event_interface *ev_int,
  71                      int ev_code,
  72                      s64 timestamp,
  73                      struct iio_shared_ev_pointer *
  74                      shared_pointer_p)
  75 {
  76         struct iio_detected_event_list *ev;
  77         int ret = 0;
  78
  79         /* Does anyone care? */
  80         mutex_lock(&ev_int->event_list_lock);
  81         if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) {
  82                 if (ev_int->current_events == ev_int->max_events)
  83                         return 0;
  84                 ev = kmalloc(sizeof(*ev), GFP_KERNEL);
  85                 if (ev == NULL) {
  86                         ret = -ENOMEM;
  87                         goto error_ret;
  88                 }
  89                 ev->ev.id = ev_code;
  90                 ev->ev.timestamp = timestamp;
  91                 ev->shared_pointer = shared_pointer_p;
  92                 if (ev->shared_pointer)
  93                         shared_pointer_p->ev_p = ev;
  94
  95                 list_add_tail(&ev->list, &ev_int->det_events.list);
  96                 ev_int->current_events++;
  97                 mutex_unlock(&ev_int->event_list_lock);
  98                 wake_up_interruptible(&ev_int->wait);
  99         } else
 100                 mutex_unlock(&ev_int->event_list_lock);
 101
 102 error_ret:
 103         return ret;
 104 }
 105 EXPORT_SYMBOL(__iio_push_event);
 106
 107 int iio_push_event(struct iio_dev *dev_info,
 108                    int ev_line,
 109                    int ev_code,
 110                    s64 timestamp)
 111 {
 112         return __iio_push_event(&dev_info->event_interfaces[ev_line],
 113                                 ev_code, timestamp, NULL);
 114 }
 115 EXPORT_SYMBOL(iio_push_event);
 116
 117 /* Generic interrupt line interrupt handler */
 118 irqreturn_t iio_interrupt_handler(int irq, void *_int_info)
 119 {
 120         struct iio_interrupt *int_info = _int_info;
 121         struct iio_dev *dev_info = int_info->dev_info;
 122         struct iio_event_handler_list *p;
 123         s64 time_ns;
 124         unsigned long flags;
 125
 126         spin_lock_irqsave(&int_info->ev_list_lock, flags);
 127         if (list_empty(&int_info->ev_list)) {
 128                 spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 129                 return IRQ_NONE;
 130         }
 131
 132         time_ns = iio_get_time_ns();
 133         /* detect single element list*/
 134         if (list_is_singular(&int_info->ev_list)) {
 135                 disable_irq_nosync(irq);
 136                 p = list_first_entry(&int_info->ev_list,
 137                                      struct iio_event_handler_list,
 138                                      list);
 139                 /* single event handler - maybe shared */
 140                 p->handler(dev_info, 1, time_ns, !(p->refcount > 1));
 141         } else
 142                 list_for_each_entry(p, &int_info->ev_list, list) {
 143                         disable_irq_nosync(irq);
 144                         p->handler(dev_info, 1, time_ns, 0);
 145                 }
 146         spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 147
 148         return IRQ_HANDLED;
 149 }
 150
 151 static struct iio_interrupt *iio_allocate_interrupt(void)
 152 {
 153         struct iio_interrupt *i = kmalloc(sizeof *i, GFP_KERNEL);
 154         if (i) {
 155                 spin_lock_init(&i->ev_list_lock);
 156                 INIT_LIST_HEAD(&i->ev_list);
 157         }
 158         return i;
 159 }
 160
 161 /* Confirming the validity of supplied irq is left to drivers.*/
 162 int iio_register_interrupt_line(unsigned int irq,
 163                                 struct iio_dev *dev_info,
 164                                 int line_number,
 165                                 unsigned long type,
 166                                 const char *name)
 167 {
 168         int ret;
 169
 170         dev_info->interrupts[line_number] = iio_allocate_interrupt();
 171         if (dev_info->interrupts[line_number] == NULL) {
 172                 ret = -ENOMEM;
 173                 goto error_ret;
 174         }
 175         dev_info->interrupts[line_number]->line_number = line_number;
 176         dev_info->interrupts[line_number]->irq = irq;
 177         dev_info->interrupts[line_number]->dev_info = dev_info;
 178
 179         /* Possibly only request on demand?
 180          * Can see this may complicate the handling of interrupts.
 181          * However, with this approach we might end up handling lots of
 182          * events no-one cares about.*/
 183         ret = request_irq(irq,
 184                           &iio_interrupt_handler,
 185                           type,
 186                           name,
 187                           dev_info->interrupts[line_number]);
 188
 189 error_ret:
 190         return ret;
 191 }
 192 EXPORT_SYMBOL(iio_register_interrupt_line);
 193
 194 /* This turns up an awful lot */
 195 ssize_t iio_read_const_attr(struct device *dev,
 196                             struct device_attribute *attr,
 197                             char *buf)
 198 {
 199         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 200 }
 201 EXPORT_SYMBOL(iio_read_const_attr);
 202
 203 /* Before this runs the interrupt generator must have been disabled */
 204 void iio_unregister_interrupt_line(struct iio_dev *dev_info, int line_number)
 205 {
 206         /* make sure the interrupt handlers are all done */
 207         flush_scheduled_work();
 208         free_irq(dev_info->interrupts[line_number]->irq,
 209                  dev_info->interrupts[line_number]);
 210         kfree(dev_info->interrupts[line_number]);
 211 }
 212 EXPORT_SYMBOL(iio_unregister_interrupt_line);
 213
 214 /* Reference counted add and remove */
 215 void iio_add_event_to_list(struct iio_event_handler_list *el,
 216                           struct list_head *head)
 217 {
 218         unsigned long flags;
 219         struct iio_interrupt *inter = to_iio_interrupt(head);
 220
 221         /* take mutex to protect this element */
 222         mutex_lock(&el->exist_lock);
 223         if (el->refcount == 0) {
 224                 /* Take the event list spin lock */
 225                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 226                 list_add(&el->list, head);
 227                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 228         }
 229         el->refcount++;
 230         mutex_unlock(&el->exist_lock);
 231 }
 232 EXPORT_SYMBOL(iio_add_event_to_list);
 233
 234 void iio_remove_event_from_list(struct iio_event_handler_list *el,
 235                                struct list_head *head)
 236 {
 237         unsigned long flags;
 238         struct iio_interrupt *inter = to_iio_interrupt(head);
 239
 240         mutex_lock(&el->exist_lock);
 241         el->refcount--;
 242         if (el->refcount == 0) {
 243                 /* Take the event list spin lock */
 244                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 245                 list_del_init(&el->list);
 246                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 247         }
 248         mutex_unlock(&el->exist_lock);
 249 }
 250 EXPORT_SYMBOL(iio_remove_event_from_list);
 251
 252 ssize_t iio_event_chrdev_read(struct file *filep,
 253                               char *buf,
 254                               size_t count,
 255                               loff_t *f_ps)
 256 {
 257         struct iio_event_interface *ev_int = filep->private_data;
 258         struct iio_detected_event_list *el;
 259         int ret;
 260         size_t len;
 261
 262         mutex_lock(&ev_int->event_list_lock);
 263         if (list_empty(&ev_int->det_events.list)) {
 264                 if (filep->f_flags & O_NONBLOCK) {
 265                         ret = -EAGAIN;
 266                         goto error_mutex_unlock;
 267                 }
 268                 mutex_unlock(&ev_int->event_list_lock);
 269                 /* Blocking on device; waiting for something to be there */
 270                 ret = wait_event_interruptible(ev_int->wait,
 271                                                !list_empty(&ev_int
 272                                                            ->det_events.list));
 273                 if (ret)
 274                         goto error_ret;
 275                 /* Single access device so noone else can get the data */
 276                 mutex_lock(&ev_int->event_list_lock);
 277         }
 278
 279         el = list_first_entry(&ev_int->det_events.list,
 280                               struct iio_detected_event_list,
 281                               list);
 282         len = sizeof el->ev;
 283         if (copy_to_user(buf, &(el->ev), len)) {
 284                 ret = -EFAULT;
 285                 goto error_mutex_unlock;
 286         }
 287         list_del(&el->list);
 288         ev_int->current_events--;
 289         mutex_unlock(&ev_int->event_list_lock);
 290         /*
 291          * Possible concurency issue if an update of this event is on its way
 292          * through. May lead to new even being removed whilst the reported event
 293          * was the unescalated event. In typical use case this is not a problem
 294          * as userspace will say read half the buffer due to a 50% full event
 295          * which would make the correct 100% full incorrect anyway.
 296          */
 297         spin_lock(&el->shared_pointer->lock);
 298         if (el->shared_pointer)
 299                 (el->shared_pointer->ev_p) = NULL;
 300         spin_unlock(&el->shared_pointer->lock);
 301
 302         kfree(el);
 303
 304         return len;
 305
 306 error_mutex_unlock:
 307         mutex_unlock(&ev_int->event_list_lock);
 308 error_ret:
 309
 310         return ret;
 311 }
 312
 313 int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 314 {
 315         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 316         struct iio_event_interface *ev_int = hand->private;
 317         struct iio_detected_event_list *el, *t;
 318
 319         mutex_lock(&ev_int->event_list_lock);
 320         clear_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags);
 321         /*
 322          * In order to maintain a clean state for reopening,
 323          * clear out any awaiting events. The mask will prevent
 324          * any new __iio_push_event calls running.
 325          */
 326         list_for_each_entry_safe(el, t, &ev_int->det_events.list, list) {
 327                 list_del(&el->list);
 328                 kfree(el);
 329         }
 330         mutex_unlock(&ev_int->event_list_lock);
 331
 332         return 0;
 333 }
 334
 335 int iio_event_chrdev_open(struct inode *inode, struct file *filep)
 336 {
 337         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 338         struct iio_event_interface *ev_int = hand->private;
 339
 340         mutex_lock(&ev_int->event_list_lock);
 341         if (test_and_set_bit(IIO_BUSY_BIT_POS, &hand->flags)) {
 342                 fops_put(filep->f_op);
 343                 mutex_unlock(&ev_int->event_list_lock);
 344                 return -EBUSY;
 345         }
 346         filep->private_data = hand->private;
 347         mutex_unlock(&ev_int->event_list_lock);
 348
 349         return 0;
 350 }
 351
 352 static const struct file_operations iio_event_chrdev_fileops = {
 353         .read =  iio_event_chrdev_read,
 354         .release = iio_event_chrdev_release,
 355         .open = iio_event_chrdev_open,
 356         .owner = THIS_MODULE,
 357 };
 358
 359 static void iio_event_dev_release(struct device *dev)
 360 {
 361         struct iio_event_interface *ev_int
 362                 = container_of(dev, struct iio_event_interface, dev);
 363         cdev_del(&ev_int->handler.chrdev);
 364         iio_device_free_chrdev_minor(MINOR(dev->devt));
 365 };
 366
 367 static struct device_type iio_event_type = {
 368         .release = iio_event_dev_release,
 369 };
 370
 371 int iio_device_get_chrdev_minor(void)
 372 {
 373         int ret, val;
 374
 375 idr_again:
 376         if (unlikely(idr_pre_get(&iio_chrdev_idr, GFP_KERNEL) == 0))
 377                 return -ENOMEM;
 378         spin_lock(&iio_idr_lock);
 379         ret = idr_get_new(&iio_chrdev_idr, NULL, &val);
 380         spin_unlock(&iio_idr_lock);
 381         if (unlikely(ret == -EAGAIN))
 382                 goto idr_again;
 383         else if (unlikely(ret))
 384                 return ret;
 385         if (val > IIO_DEV_MAX)
 386                 return -ENOMEM;
 387         return val;
 388 }
 389
 390 void iio_device_free_chrdev_minor(int val)
 391 {
 392         spin_lock(&iio_idr_lock);
 393         idr_remove(&iio_chrdev_idr, val);
 394         spin_unlock(&iio_idr_lock);
 395 }
 396
 397 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 398                      const char *name,
 399                      struct module *owner,
 400                      struct device *dev)
 401 {
 402         int ret, minor;
 403
 404         ev_int->dev.class = &iio_class;
 405         ev_int->dev.parent = dev;
 406         ev_int->dev.type = &iio_event_type;
 407         device_initialize(&ev_int->dev);
 408
 409         minor = iio_device_get_chrdev_minor();
 410         if (minor < 0) {
 411                 ret = minor;
 412                 goto error_device_put;
 413         }
 414         ev_int->dev.devt = MKDEV(MAJOR(iio_devt), minor);
 415         dev_set_name(&ev_int->dev, "%s", name);
 416
 417         ret = device_add(&ev_int->dev);
 418         if (ret)
 419                 goto error_free_minor;
 420
 421         cdev_init(&ev_int->handler.chrdev, &iio_event_chrdev_fileops);
 422         ev_int->handler.chrdev.owner = owner;
 423
 424         mutex_init(&ev_int->event_list_lock);
 425         /* discussion point - make this variable? */
 426         ev_int->max_events = 10;
 427         ev_int->current_events = 0;
 428         INIT_LIST_HEAD(&ev_int->det_events.list);
 429         init_waitqueue_head(&ev_int->wait);
 430         ev_int->handler.private = ev_int;
 431         ev_int->handler.flags = 0;
 432
 433         ret = cdev_add(&ev_int->handler.chrdev, ev_int->dev.devt, 1);
 434         if (ret)
 435                 goto error_unreg_device;
 436
 437         return 0;
 438
 439 error_unreg_device:
 440         device_unregister(&ev_int->dev);
 441 error_free_minor:
 442         iio_device_free_chrdev_minor(minor);
 443 error_device_put:
 444         put_device(&ev_int->dev);
 445
 446         return ret;
 447 }
 448
 449 void iio_free_ev_int(struct iio_event_interface *ev_int)
 450 {
 451         device_unregister(&ev_int->dev);
 452         put_device(&ev_int->dev);
 453 }
 454
 455 static int __init iio_dev_init(void)
 456 {
 457         int err;
 458
 459         err = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 460         if (err < 0)
 461                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 462                        __FILE__);
 463
 464         return err;
 465 }
 466
 467 static void __exit iio_dev_exit(void)
 468 {
 469         if (iio_devt)
 470                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 471 }
 472
 473 static int __init iio_init(void)
 474 {
 475         int ret;
 476
 477         /* Create sysfs class */
 478         ret  = class_register(&iio_class);
 479         if (ret < 0) {
 480                 printk(KERN_ERR
 481                        "%s could not create sysfs class\n",
 482                         __FILE__);
 483                 goto error_nothing;
 484         }
 485
 486         ret = iio_dev_init();
 487         if (ret < 0)
 488                 goto error_unregister_class;
 489
 490         return 0;
 491
 492 error_unregister_class:
 493         class_unregister(&iio_class);
 494 error_nothing:
 495         return ret;
 496 }
 497
 498 static void __exit iio_exit(void)
 499 {
 500         iio_dev_exit();
 501         class_unregister(&iio_class);
 502 }
 503
 504 static int iio_device_register_sysfs(struct iio_dev *dev_info)
 505 {
 506         int ret = 0;
 507
 508         ret = sysfs_create_group(&dev_info->dev.kobj, dev_info->attrs);
 509         if (ret) {
 510                 dev_err(dev_info->dev.parent,
 511                         "Failed to register sysfs hooks\n");
 512                 goto error_ret;
 513         }
 514
 515         if (dev_info->scan_el_attrs) {
 516                 ret = sysfs_create_group(&dev_info->dev.kobj,
 517                                          dev_info->scan_el_attrs);
 518                 if (ret)
 519                         dev_err(&dev_info->dev,
 520                                 "Failed to add sysfs scan els\n");
 521         }
 522
 523 error_ret:
 524         return ret;
 525 }
 526
 527 static void iio_device_unregister_sysfs(struct iio_dev *dev_info)
 528 {
 529         if (dev_info->scan_el_attrs)
 530                 sysfs_remove_group(&dev_info->dev.kobj,
 531                                    dev_info->scan_el_attrs);
 532
 533         sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
 534 }
 535
 536 int iio_get_new_idr_val(struct idr *this_idr)
 537 {
 538         int ret;
 539         int val;
 540
 541 idr_again:
 542         if (unlikely(idr_pre_get(this_idr, GFP_KERNEL) == 0))
 543                 return -ENOMEM;
 544
 545         spin_lock(&iio_idr_lock);
 546         ret = idr_get_new(this_idr, NULL, &val);
 547         spin_unlock(&iio_idr_lock);
 548         if (unlikely(ret == -EAGAIN))
 549                 goto idr_again;
 550         else if (unlikely(ret))
 551                 return ret;
 552
 553         return val;
 554 }
 555 EXPORT_SYMBOL(iio_get_new_idr_val);
 556
 557 void iio_free_idr_val(struct idr *this_idr, int id)
 558 {
 559         spin_lock(&iio_idr_lock);
 560         idr_remove(this_idr, id);
 561         spin_unlock(&iio_idr_lock);
 562 }
 563 EXPORT_SYMBOL(iio_free_idr_val);
 564
 565 static int iio_device_register_id(struct iio_dev *dev_info,
 566                                   struct idr *this_idr)
 567 {
 568
 569         dev_info->id = iio_get_new_idr_val(&iio_idr);
 570         if (dev_info->id < 0)
 571                 return dev_info->id;
 572         return 0;
 573 }
 574
 575 static void iio_device_unregister_id(struct iio_dev *dev_info)
 576 {
 577         iio_free_idr_val(&iio_idr, dev_info->id);
 578 }
 579
 580 static inline int __iio_add_event_config_attrs(struct iio_dev *dev_info, int i)
 581 {
 582         int ret;
 583         /*p for adding, q for removing */
 584         struct attribute **attrp, **attrq;
 585
 586         if (dev_info->event_conf_attrs && dev_info->event_conf_attrs[i].attrs) {
 587                 attrp = dev_info->event_conf_attrs[i].attrs;
 588                 while (*attrp) {
 589                         ret =  sysfs_add_file_to_group(&dev_info->dev.kobj,
 590                                                        *attrp,
 591                                                        dev_info
 592                                                        ->event_attrs[i].name);
 593                         if (ret)
 594                                 goto error_ret;
 595                         attrp++;
 596                 }
 597         }
 598         return 0;
 599
 600 error_ret:
 601         attrq = dev_info->event_conf_attrs[i].attrs;
 602         while (attrq != attrp) {
 603                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 604                                              *attrq,
 605                                              dev_info->event_attrs[i].name);
 606                 attrq++;
 607         }
 608
 609         return ret;
 610 }
 611
 612 static inline int __iio_remove_event_config_attrs(struct iio_dev *dev_info,
 613                                                   int i)
 614 {
 615         struct attribute **attrq;
 616
 617         if (dev_info->event_conf_attrs
 618                 && dev_info->event_conf_attrs[i].attrs) {
 619                 attrq = dev_info->event_conf_attrs[i].attrs;
 620                 while (*attrq) {
 621                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 622                                                      *attrq,
 623                                                      dev_info
 624                                                      ->event_attrs[i].name);
 625                         attrq++;
 626                 }
 627         }
 628
 629         return 0;
 630 }
 631
 632 static int iio_device_register_eventset(struct iio_dev *dev_info)
 633 {
 634         int ret = 0, i, j;
 635
 636         if (dev_info->num_interrupt_lines == 0)
 637                 return 0;
 638
 639         dev_info->event_interfaces =
 640                 kzalloc(sizeof(struct iio_event_interface)
 641                         *dev_info->num_interrupt_lines,
 642                         GFP_KERNEL);
 643         if (dev_info->event_interfaces == NULL) {
 644                 ret = -ENOMEM;
 645                 goto error_ret;
 646         }
 647
 648         dev_info->interrupts = kzalloc(sizeof(struct iio_interrupt *)
 649                                        *dev_info->num_interrupt_lines,
 650                                        GFP_KERNEL);
 651         if (dev_info->interrupts == NULL) {
 652                 ret = -ENOMEM;
 653                 goto error_free_event_interfaces;
 654         }
 655
 656         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 657                 dev_info->event_interfaces[i].owner = dev_info->driver_module;
 658                 ret = iio_get_new_idr_val(&iio_event_idr);
 659                 if (ret)
 660                         goto error_free_setup_ev_ints;
 661                 else
 662                         dev_info->event_interfaces[i].id = ret;
 663
 664                 snprintf(dev_info->event_interfaces[i]._name, 20,
 665                          "event_line%d",
 666                         dev_info->event_interfaces[i].id);
 667
 668                 ret = iio_setup_ev_int(&dev_info->event_interfaces[i],
 669                                        (const char *)(dev_info
 670                                                       ->event_interfaces[i]
 671                                                       ._name),
 672                                        dev_info->driver_module,
 673                                        &dev_info->dev);
 674                 if (ret) {
 675                         dev_err(&dev_info->dev,
 676                                 "Could not get chrdev interface\n");
 677                         iio_free_idr_val(&iio_event_idr,
 678                                          dev_info->event_interfaces[i].id);
 679                         goto error_free_setup_ev_ints;
 680                 }
 681         }
 682
 683         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 684                 snprintf(dev_info->event_interfaces[i]._attrname, 20,
 685                         "event_line%d_sources", i);
 686                 dev_info->event_attrs[i].name
 687                         = (const char *)
 688                         (dev_info->event_interfaces[i]._attrname);
 689                 ret = sysfs_create_group(&dev_info->dev.kobj,
 690                                          &dev_info->event_attrs[i]);
 691                 if (ret) {
 692                         dev_err(&dev_info->dev,
 693                                 "Failed to register sysfs for event attrs");
 694                         goto error_remove_sysfs_interfaces;
 695                 }
 696         }
 697
 698         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 699                 ret = __iio_add_event_config_attrs(dev_info, i);
 700                 if (ret)
 701                         goto error_unregister_config_attrs;
 702         }
 703
 704         return 0;
 705
 706 error_unregister_config_attrs:
 707         for (j = 0; j < i; j++)
 708                 __iio_remove_event_config_attrs(dev_info, i);
 709         i = dev_info->num_interrupt_lines - 1;
 710 error_remove_sysfs_interfaces:
 711         for (j = 0; j < i; j++)
 712                 sysfs_remove_group(&dev_info->dev.kobj,
 713                                    &dev_info->event_attrs[j]);
 714         i = dev_info->num_interrupt_lines - 1;
 715 error_free_setup_ev_ints:
 716         for (j = 0; j < i; j++) {
 717                 iio_free_idr_val(&iio_event_idr,
 718                                  dev_info->event_interfaces[i].id);
 719                 iio_free_ev_int(&dev_info->event_interfaces[j]);
 720         }
 721         kfree(dev_info->interrupts);
 722 error_free_event_interfaces:
 723         kfree(dev_info->event_interfaces);
 724 error_ret:
 725
 726         return ret;
 727 }
 728
 729 static void iio_device_unregister_eventset(struct iio_dev *dev_info)
 730 {
 731         int i;
 732
 733         if (dev_info->num_interrupt_lines == 0)
 734                 return;
 735         for (i = 0; i < dev_info->num_interrupt_lines; i++)
 736                 sysfs_remove_group(&dev_info->dev.kobj,
 737                                    &dev_info->event_attrs[i]);
 738
 739         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 740                 iio_free_idr_val(&iio_event_idr,
 741                                  dev_info->event_interfaces[i].id);
 742                 iio_free_ev_int(&dev_info->event_interfaces[i]);
 743         }
 744         kfree(dev_info->interrupts);
 745         kfree(dev_info->event_interfaces);
 746 }
 747
 748 static void iio_dev_release(struct device *device)
 749 {
 750         struct iio_dev *dev = to_iio_dev(device);
 751
 752         iio_put();
 753         kfree(dev);
 754 }
 755
 756 static struct device_type iio_dev_type = {
 757         .name = "iio_device",
 758         .release = iio_dev_release,
 759 };
 760
 761 struct iio_dev *iio_allocate_device(void)
 762 {
 763         struct iio_dev *dev = kzalloc(sizeof *dev, GFP_KERNEL);
 764
 765         if (dev) {
 766                 dev->dev.type = &iio_dev_type;
 767                 dev->dev.class = &iio_class;
 768                 device_initialize(&dev->dev);
 769                 dev_set_drvdata(&dev->dev, (void *)dev);
 770                 mutex_init(&dev->mlock);
 771                 iio_get();
 772         }
 773
 774         return dev;
 775 }
 776 EXPORT_SYMBOL(iio_allocate_device);
 777
 778 void iio_free_device(struct iio_dev *dev)
 779 {
 780         if (dev)
 781                 iio_put_device(dev);
 782 }
 783 EXPORT_SYMBOL(iio_free_device);
 784
 785 int iio_device_register(struct iio_dev *dev_info)
 786 {
 787         int ret;
 788
 789         ret = iio_device_register_id(dev_info, &iio_idr);
 790         if (ret) {
 791                 dev_err(&dev_info->dev, "Failed to get id\n");
 792                 goto error_ret;
 793         }
 794         dev_set_name(&dev_info->dev, "device%d", dev_info->id);
 795
 796         ret = device_add(&dev_info->dev);
 797         if (ret)
 798                 goto error_free_idr;
 799         ret = iio_device_register_sysfs(dev_info);
 800         if (ret) {
 801                 dev_err(dev_info->dev.parent,
 802                         "Failed to register sysfs interfaces\n");
 803                 goto error_del_device;
 804         }
 805         ret = iio_device_register_eventset(dev_info);
 806         if (ret) {
 807                 dev_err(dev_info->dev.parent,
 808                         "Failed to register event set \n");
 809                 goto error_free_sysfs;
 810         }
 811         if (dev_info->modes & INDIO_RING_TRIGGERED)
 812                 iio_device_register_trigger_consumer(dev_info);
 813
 814         return 0;
 815
 816 error_free_sysfs:
 817         iio_device_unregister_sysfs(dev_info);
 818 error_del_device:
 819         device_del(&dev_info->dev);
 820 error_free_idr:
 821         iio_device_unregister_id(dev_info);
 822 error_ret:
 823         return ret;
 824 }
 825 EXPORT_SYMBOL(iio_device_register);
 826
 827 void iio_device_unregister(struct iio_dev *dev_info)
 828 {
 829         if (dev_info->modes & INDIO_RING_TRIGGERED)
 830                 iio_device_unregister_trigger_consumer(dev_info);
 831         iio_device_unregister_eventset(dev_info);
 832         iio_device_unregister_sysfs(dev_info);
 833         iio_device_unregister_id(dev_info);
 834         device_unregister(&dev_info->dev);
 835 }
 836 EXPORT_SYMBOL(iio_device_unregister);
 837
 838 void iio_put(void)
 839 {
 840         module_put(THIS_MODULE);
 841 }
 842
 843 void iio_get(void)
 844 {
 845         __module_get(THIS_MODULE);
 846 }
 847
 848 subsys_initcall(iio_init);
 849 module_exit(iio_exit);
 850
 851 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 852 MODULE_DESCRIPTION("Industrial I/O core");
 853 MODULE_LICENSE("GPL");