SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/cdev.h>
  23 #include "iio.h"
  24 #include "trigger_consumer.h"
  25
  26 #define IIO_ID_PREFIX "device"
  27 #define IIO_ID_FORMAT IIO_ID_PREFIX "%d"
  28
  29 /* IDR to assign each registered device a unique id*/
  30 static DEFINE_IDR(iio_idr);
  31
  32 /* IDR for general event identifiers */
  33 static DEFINE_IDR(iio_event_idr);
  34 /* IDR to allocate character device minor numbers */
  35 static DEFINE_IDR(iio_chrdev_idr);
  36 /* Lock used to protect both of the above */
  37 static DEFINE_SPINLOCK(iio_idr_lock);
  38
  39 dev_t iio_devt;
  40 EXPORT_SYMBOL(iio_devt);
  41
  42 #define IIO_DEV_MAX 256
  43 static char *iio_devnode(struct device *dev, mode_t *mode)
  44 {
  45         return kasprintf(GFP_KERNEL, "iio/%s", dev_name(dev));
  46 }
  47
  48 struct class iio_class = {
  49         .name = "iio",
  50         .devnode = iio_devnode,
  51 };
  52 EXPORT_SYMBOL(iio_class);
  53
  54 void __iio_change_event(struct iio_detected_event_list *ev,
  55                         int ev_code,
  56                         s64 timestamp)
  57 {
  58         ev->ev.id = ev_code;
  59         ev->ev.timestamp = timestamp;
  60 }
  61 EXPORT_SYMBOL(__iio_change_event);
  62
  63 /* Used both in the interrupt line put events and the ring buffer ones */
  64
  65 /* Note that in it's current form someone has to be listening before events
  66  * are queued. Hence a client MUST open the chrdev before the ring buffer is
  67  * switched on.
  68  */
  69  int __iio_push_event(struct iio_event_interface *ev_int,
  70                      int ev_code,
  71                      s64 timestamp,
  72                      struct iio_shared_ev_pointer *
  73                      shared_pointer_p)
  74 {
  75         struct iio_detected_event_list *ev;
  76         int ret = 0;
  77
  78         /* Does anyone care? */
  79         mutex_lock(&ev_int->event_list_lock);
  80         if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) {
  81                 if (ev_int->current_events == ev_int->max_events)
  82                         return 0;
  83                 ev = kmalloc(sizeof(*ev), GFP_KERNEL);
  84                 if (ev == NULL) {
  85                         ret = -ENOMEM;
  86                         goto error_ret;
  87                 }
  88                 ev->ev.id = ev_code;
  89                 ev->ev.timestamp = timestamp;
  90                 ev->shared_pointer = shared_pointer_p;
  91                 if (ev->shared_pointer)
  92                         shared_pointer_p->ev_p = ev;
  93
  94                 list_add_tail(&ev->list, &ev_int->det_events.list);
  95                 ev_int->current_events++;
  96                 mutex_unlock(&ev_int->event_list_lock);
  97                 wake_up_interruptible(&ev_int->wait);
  98         } else
  99                 mutex_unlock(&ev_int->event_list_lock);
 100
 101 error_ret:
 102         return ret;
 103 }
 104 EXPORT_SYMBOL(__iio_push_event);
 105
 106 int iio_push_event(struct iio_dev *dev_info,
 107                    int ev_line,
 108                    int ev_code,
 109                    s64 timestamp)
 110 {
 111         return __iio_push_event(&dev_info->event_interfaces[ev_line],
 112                                 ev_code, timestamp, NULL);
 113 }
 114 EXPORT_SYMBOL(iio_push_event);
 115
 116 /* Generic interrupt line interrupt handler */
 117 irqreturn_t iio_interrupt_handler(int irq, void *_int_info)
 118 {
 119         struct iio_interrupt *int_info = _int_info;
 120         struct iio_dev *dev_info = int_info->dev_info;
 121         struct iio_event_handler_list *p;
 122         s64 time_ns;
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(&int_info->ev_list_lock, flags);
 126         if (list_empty(&int_info->ev_list)) {
 127                 spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 128                 return IRQ_NONE;
 129         }
 130
 131         time_ns = iio_get_time_ns();
 132         /* detect single element list*/
 133         if (list_is_singular(&int_info->ev_list)) {
 134                 disable_irq_nosync(irq);
 135                 p = list_first_entry(&int_info->ev_list,
 136                                      struct iio_event_handler_list,
 137                                      list);
 138                 /* single event handler - maybe shared */
 139                 p->handler(dev_info, 1, time_ns, !(p->refcount > 1));
 140         } else
 141                 list_for_each_entry(p, &int_info->ev_list, list) {
 142                         disable_irq_nosync(irq);
 143                         p->handler(dev_info, 1, time_ns, 0);
 144                 }
 145         spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 146
 147         return IRQ_HANDLED;
 148 }
 149
 150 static struct iio_interrupt *iio_allocate_interrupt(void)
 151 {
 152         struct iio_interrupt *i = kmalloc(sizeof *i, GFP_KERNEL);
 153         if (i) {
 154                 spin_lock_init(&i->ev_list_lock);
 155                 INIT_LIST_HEAD(&i->ev_list);
 156         }
 157         return i;
 158 }
 159
 160 /* Confirming the validity of supplied irq is left to drivers.*/
 161 int iio_register_interrupt_line(unsigned int irq,
 162                                 struct iio_dev *dev_info,
 163                                 int line_number,
 164                                 unsigned long type,
 165                                 const char *name)
 166 {
 167         int ret;
 168
 169         dev_info->interrupts[line_number] = iio_allocate_interrupt();
 170         if (dev_info->interrupts[line_number] == NULL) {
 171                 ret = -ENOMEM;
 172                 goto error_ret;
 173         }
 174         dev_info->interrupts[line_number]->line_number = line_number;
 175         dev_info->interrupts[line_number]->irq = irq;
 176         dev_info->interrupts[line_number]->dev_info = dev_info;
 177
 178         /* Possibly only request on demand?
 179          * Can see this may complicate the handling of interrupts.
 180          * However, with this approach we might end up handling lots of
 181          * events no-one cares about.*/
 182         ret = request_irq(irq,
 183                           &iio_interrupt_handler,
 184                           type,
 185                           name,
 186                           dev_info->interrupts[line_number]);
 187
 188 error_ret:
 189         return ret;
 190 }
 191 EXPORT_SYMBOL(iio_register_interrupt_line);
 192
 193 /* This turns up an awful lot */
 194 ssize_t iio_read_const_attr(struct device *dev,
 195                             struct device_attribute *attr,
 196                             char *buf)
 197 {
 198         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 199 }
 200 EXPORT_SYMBOL(iio_read_const_attr);
 201
 202 /* Before this runs the interrupt generator must have been disabled */
 203 void iio_unregister_interrupt_line(struct iio_dev *dev_info, int line_number)
 204 {
 205         /* make sure the interrupt handlers are all done */
 206         flush_scheduled_work();
 207         free_irq(dev_info->interrupts[line_number]->irq,
 208                  dev_info->interrupts[line_number]);
 209         kfree(dev_info->interrupts[line_number]);
 210 }
 211 EXPORT_SYMBOL(iio_unregister_interrupt_line);
 212
 213 /* Reference counted add and remove */
 214 void iio_add_event_to_list(struct iio_event_handler_list *el,
 215                           struct list_head *head)
 216 {
 217         unsigned long flags;
 218         struct iio_interrupt *inter = to_iio_interrupt(head);
 219
 220         /* take mutex to protect this element */
 221         mutex_lock(&el->exist_lock);
 222         if (el->refcount == 0) {
 223                 /* Take the event list spin lock */
 224                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 225                 list_add(&el->list, head);
 226                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 227         }
 228         el->refcount++;
 229         mutex_unlock(&el->exist_lock);
 230 }
 231 EXPORT_SYMBOL(iio_add_event_to_list);
 232
 233 void iio_remove_event_from_list(struct iio_event_handler_list *el,
 234                                struct list_head *head)
 235 {
 236         unsigned long flags;
 237         struct iio_interrupt *inter = to_iio_interrupt(head);
 238
 239         mutex_lock(&el->exist_lock);
 240         el->refcount--;
 241         if (el->refcount == 0) {
 242                 /* Take the event list spin lock */
 243                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 244                 list_del_init(&el->list);
 245                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 246         }
 247         mutex_unlock(&el->exist_lock);
 248 }
 249 EXPORT_SYMBOL(iio_remove_event_from_list);
 250
 251 ssize_t iio_event_chrdev_read(struct file *filep,
 252                               char *buf,
 253                               size_t count,
 254                               loff_t *f_ps)
 255 {
 256         struct iio_event_interface *ev_int = filep->private_data;
 257         struct iio_detected_event_list *el;
 258         int ret;
 259         size_t len;
 260
 261         mutex_lock(&ev_int->event_list_lock);
 262         if (list_empty(&ev_int->det_events.list)) {
 263                 if (filep->f_flags & O_NONBLOCK) {
 264                         ret = -EAGAIN;
 265                         goto error_mutex_unlock;
 266                 }
 267                 mutex_unlock(&ev_int->event_list_lock);
 268                 /* Blocking on device; waiting for something to be there */
 269                 ret = wait_event_interruptible(ev_int->wait,
 270                                                !list_empty(&ev_int
 271                                                            ->det_events.list));
 272                 if (ret)
 273                         goto error_ret;
 274                 /* Single access device so noone else can get the data */
 275                 mutex_lock(&ev_int->event_list_lock);
 276         }
 277
 278         el = list_first_entry(&ev_int->det_events.list,
 279                               struct iio_detected_event_list,
 280                               list);
 281         len = sizeof el->ev;
 282         if (copy_to_user(buf, &(el->ev), len)) {
 283                 ret = -EFAULT;
 284                 goto error_mutex_unlock;
 285         }
 286         list_del(&el->list);
 287         ev_int->current_events--;
 288         mutex_unlock(&ev_int->event_list_lock);
 289         /*
 290          * Possible concurency issue if an update of this event is on its way
 291          * through. May lead to new even being removed whilst the reported event
 292          * was the unescalated event. In typical use case this is not a problem
 293          * as userspace will say read half the buffer due to a 50% full event
 294          * which would make the correct 100% full incorrect anyway.
 295          */
 296         spin_lock(&el->shared_pointer->lock);
 297         if (el->shared_pointer)
 298                 (el->shared_pointer->ev_p) = NULL;
 299         spin_unlock(&el->shared_pointer->lock);
 300
 301         kfree(el);
 302
 303         return len;
 304
 305 error_mutex_unlock:
 306         mutex_unlock(&ev_int->event_list_lock);
 307 error_ret:
 308
 309         return ret;
 310 }
 311
 312 int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 313 {
 314         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 315         struct iio_event_interface *ev_int = hand->private;
 316         struct iio_detected_event_list *el, *t;
 317
 318         mutex_lock(&ev_int->event_list_lock);
 319         clear_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags);
 320         /*
 321          * In order to maintain a clean state for reopening,
 322          * clear out any awaiting events. The mask will prevent
 323          * any new __iio_push_event calls running.
 324          */
 325         list_for_each_entry_safe(el, t, &ev_int->det_events.list, list) {
 326                 list_del(&el->list);
 327                 kfree(el);
 328         }
 329         mutex_unlock(&ev_int->event_list_lock);
 330
 331         return 0;
 332 }
 333
 334 int iio_event_chrdev_open(struct inode *inode, struct file *filep)
 335 {
 336         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 337         struct iio_event_interface *ev_int = hand->private;
 338
 339         mutex_lock(&ev_int->event_list_lock);
 340         if (test_and_set_bit(IIO_BUSY_BIT_POS, &hand->flags)) {
 341                 fops_put(filep->f_op);
 342                 mutex_unlock(&ev_int->event_list_lock);
 343                 return -EBUSY;
 344         }
 345         filep->private_data = hand->private;
 346         mutex_unlock(&ev_int->event_list_lock);
 347
 348         return 0;
 349 }
 350
 351 static const struct file_operations iio_event_chrdev_fileops = {
 352         .read =  iio_event_chrdev_read,
 353         .release = iio_event_chrdev_release,
 354         .open = iio_event_chrdev_open,
 355         .owner = THIS_MODULE,
 356 };
 357
 358 static void iio_event_dev_release(struct device *dev)
 359 {
 360         struct iio_event_interface *ev_int
 361                 = container_of(dev, struct iio_event_interface, dev);
 362         cdev_del(&ev_int->handler.chrdev);
 363         iio_device_free_chrdev_minor(MINOR(dev->devt));
 364 };
 365
 366 static struct device_type iio_event_type = {
 367         .release = iio_event_dev_release,
 368 };
 369
 370 int iio_device_get_chrdev_minor(void)
 371 {
 372         int ret, val;
 373
 374 idr_again:
 375         if (unlikely(idr_pre_get(&iio_chrdev_idr, GFP_KERNEL) == 0))
 376                 return -ENOMEM;
 377         spin_lock(&iio_idr_lock);
 378         ret = idr_get_new(&iio_chrdev_idr, NULL, &val);
 379         spin_unlock(&iio_idr_lock);
 380         if (unlikely(ret == -EAGAIN))
 381                 goto idr_again;
 382         else if (unlikely(ret))
 383                 return ret;
 384         if (val > IIO_DEV_MAX)
 385                 return -ENOMEM;
 386         return val;
 387 }
 388
 389 void iio_device_free_chrdev_minor(int val)
 390 {
 391         spin_lock(&iio_idr_lock);
 392         idr_remove(&iio_chrdev_idr, val);
 393         spin_unlock(&iio_idr_lock);
 394 }
 395
 396 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 397                      const char *name,
 398                      struct module *owner,
 399                      struct device *dev)
 400 {
 401         int ret, minor;
 402
 403         ev_int->dev.class = &iio_class;
 404         ev_int->dev.parent = dev;
 405         ev_int->dev.type = &iio_event_type;
 406         device_initialize(&ev_int->dev);
 407
 408         minor = iio_device_get_chrdev_minor();
 409         if (minor < 0) {
 410                 ret = minor;
 411                 goto error_device_put;
 412         }
 413         ev_int->dev.devt = MKDEV(MAJOR(iio_devt), minor);
 414         dev_set_name(&ev_int->dev, "%s", name);
 415
 416         ret = device_add(&ev_int->dev);
 417         if (ret)
 418                 goto error_free_minor;
 419
 420         cdev_init(&ev_int->handler.chrdev, &iio_event_chrdev_fileops);
 421         ev_int->handler.chrdev.owner = owner;
 422
 423         mutex_init(&ev_int->event_list_lock);
 424         /* discussion point - make this variable? */
 425         ev_int->max_events = 10;
 426         ev_int->current_events = 0;
 427         INIT_LIST_HEAD(&ev_int->det_events.list);
 428         init_waitqueue_head(&ev_int->wait);
 429         ev_int->handler.private = ev_int;
 430         ev_int->handler.flags = 0;
 431
 432         ret = cdev_add(&ev_int->handler.chrdev, ev_int->dev.devt, 1);
 433         if (ret)
 434                 goto error_unreg_device;
 435
 436         return 0;
 437
 438 error_unreg_device:
 439         device_unregister(&ev_int->dev);
 440 error_free_minor:
 441         iio_device_free_chrdev_minor(minor);
 442 error_device_put:
 443         put_device(&ev_int->dev);
 444
 445         return ret;
 446 }
 447
 448 void iio_free_ev_int(struct iio_event_interface *ev_int)
 449 {
 450         device_unregister(&ev_int->dev);
 451         put_device(&ev_int->dev);
 452 }
 453
 454 static int __init iio_dev_init(void)
 455 {
 456         int err;
 457
 458         err = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 459         if (err < 0)
 460                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 461                        __FILE__);
 462
 463         return err;
 464 }
 465
 466 static void __exit iio_dev_exit(void)
 467 {
 468         if (iio_devt)
 469                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 470 }
 471
 472 static int __init iio_init(void)
 473 {
 474         int ret;
 475
 476         /* Create sysfs class */
 477         ret  = class_register(&iio_class);
 478         if (ret < 0) {
 479                 printk(KERN_ERR
 480                        "%s could not create sysfs class\n",
 481                         __FILE__);
 482                 goto error_nothing;
 483         }
 484
 485         ret = iio_dev_init();
 486         if (ret < 0)
 487                 goto error_unregister_class;
 488
 489         return 0;
 490
 491 error_unregister_class:
 492         class_unregister(&iio_class);
 493 error_nothing:
 494         return ret;
 495 }
 496
 497 static void __exit iio_exit(void)
 498 {
 499         iio_dev_exit();
 500         class_unregister(&iio_class);
 501 }
 502
 503 static int iio_device_register_sysfs(struct iio_dev *dev_info)
 504 {
 505         int ret = 0;
 506
 507         ret = sysfs_create_group(&dev_info->dev.kobj, dev_info->attrs);
 508         if (ret) {
 509                 dev_err(dev_info->dev.parent,
 510                         "Failed to register sysfs hooks\n");
 511                 goto error_ret;
 512         }
 513
 514         if (dev_info->scan_el_attrs) {
 515                 ret = sysfs_create_group(&dev_info->dev.kobj,
 516                                          dev_info->scan_el_attrs);
 517                 if (ret)
 518                         dev_err(&dev_info->dev,
 519                                 "Failed to add sysfs scan els\n");
 520         }
 521
 522 error_ret:
 523         return ret;
 524 }
 525
 526 static void iio_device_unregister_sysfs(struct iio_dev *dev_info)
 527 {
 528         if (dev_info->scan_el_attrs)
 529                 sysfs_remove_group(&dev_info->dev.kobj,
 530                                    dev_info->scan_el_attrs);
 531
 532         sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
 533 }
 534
 535 int iio_get_new_idr_val(struct idr *this_idr)
 536 {
 537         int ret;
 538         int val;
 539
 540 idr_again:
 541         if (unlikely(idr_pre_get(this_idr, GFP_KERNEL) == 0))
 542                 return -ENOMEM;
 543
 544         spin_lock(&iio_idr_lock);
 545         ret = idr_get_new(this_idr, NULL, &val);
 546         spin_unlock(&iio_idr_lock);
 547         if (unlikely(ret == -EAGAIN))
 548                 goto idr_again;
 549         else if (unlikely(ret))
 550                 return ret;
 551
 552         return val;
 553 }
 554 EXPORT_SYMBOL(iio_get_new_idr_val);
 555
 556 void iio_free_idr_val(struct idr *this_idr, int id)
 557 {
 558         spin_lock(&iio_idr_lock);
 559         idr_remove(this_idr, id);
 560         spin_unlock(&iio_idr_lock);
 561 }
 562 EXPORT_SYMBOL(iio_free_idr_val);
 563
 564 static int iio_device_register_id(struct iio_dev *dev_info,
 565                                   struct idr *this_idr)
 566 {
 567
 568         dev_info->id = iio_get_new_idr_val(&iio_idr);
 569         if (dev_info->id < 0)
 570                 return dev_info->id;
 571         return 0;
 572 }
 573
 574 static void iio_device_unregister_id(struct iio_dev *dev_info)
 575 {
 576         iio_free_idr_val(&iio_idr, dev_info->id);
 577 }
 578
 579 static inline int __iio_add_event_config_attrs(struct iio_dev *dev_info, int i)
 580 {
 581         int ret;
 582         /*p for adding, q for removing */
 583         struct attribute **attrp, **attrq;
 584
 585         if (dev_info->event_conf_attrs && dev_info->event_conf_attrs[i].attrs) {
 586                 attrp = dev_info->event_conf_attrs[i].attrs;
 587                 while (*attrp) {
 588                         ret =  sysfs_add_file_to_group(&dev_info->dev.kobj,
 589                                                        *attrp,
 590                                                        dev_info
 591                                                        ->event_attrs[i].name);
 592                         if (ret)
 593                                 goto error_ret;
 594                         attrp++;
 595                 }
 596         }
 597         return 0;
 598
 599 error_ret:
 600         attrq = dev_info->event_conf_attrs[i].attrs;
 601         while (attrq != attrp) {
 602                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 603                                              *attrq,
 604                                              dev_info->event_attrs[i].name);
 605                 attrq++;
 606         }
 607
 608         return ret;
 609 }
 610
 611 static inline int __iio_remove_event_config_attrs(struct iio_dev *dev_info,
 612                                                   int i)
 613 {
 614         struct attribute **attrq;
 615
 616         if (dev_info->event_conf_attrs
 617                 && dev_info->event_conf_attrs[i].attrs) {
 618                 attrq = dev_info->event_conf_attrs[i].attrs;
 619                 while (*attrq) {
 620                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 621                                                      *attrq,
 622                                                      dev_info
 623                                                      ->event_attrs[i].name);
 624                         attrq++;
 625                 }
 626         }
 627
 628         return 0;
 629 }
 630
 631 static int iio_device_register_eventset(struct iio_dev *dev_info)
 632 {
 633         int ret = 0, i, j;
 634
 635         if (dev_info->num_interrupt_lines == 0)
 636                 return 0;
 637
 638         dev_info->event_interfaces =
 639                 kzalloc(sizeof(struct iio_event_interface)
 640                         *dev_info->num_interrupt_lines,
 641                         GFP_KERNEL);
 642         if (dev_info->event_interfaces == NULL) {
 643                 ret = -ENOMEM;
 644                 goto error_ret;
 645         }
 646
 647         dev_info->interrupts = kzalloc(sizeof(struct iio_interrupt *)
 648                                        *dev_info->num_interrupt_lines,
 649                                        GFP_KERNEL);
 650         if (dev_info->interrupts == NULL) {
 651                 ret = -ENOMEM;
 652                 goto error_free_event_interfaces;
 653         }
 654
 655         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 656                 dev_info->event_interfaces[i].owner = dev_info->driver_module;
 657                 ret = iio_get_new_idr_val(&iio_event_idr);
 658                 if (ret)
 659                         goto error_free_setup_ev_ints;
 660                 else
 661                         dev_info->event_interfaces[i].id = ret;
 662
 663                 snprintf(dev_info->event_interfaces[i]._name, 20,
 664                          "event_line%d",
 665                         dev_info->event_interfaces[i].id);
 666
 667                 ret = iio_setup_ev_int(&dev_info->event_interfaces[i],
 668                                        (const char *)(dev_info
 669                                                       ->event_interfaces[i]
 670                                                       ._name),
 671                                        dev_info->driver_module,
 672                                        &dev_info->dev);
 673                 if (ret) {
 674                         dev_err(&dev_info->dev,
 675                                 "Could not get chrdev interface\n");
 676                         iio_free_idr_val(&iio_event_idr,
 677                                          dev_info->event_interfaces[i].id);
 678                         goto error_free_setup_ev_ints;
 679                 }
 680         }
 681
 682         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 683                 snprintf(dev_info->event_interfaces[i]._attrname, 20,
 684                         "event_line%d_sources", i);
 685                 dev_info->event_attrs[i].name
 686                         = (const char *)
 687                         (dev_info->event_interfaces[i]._attrname);
 688                 ret = sysfs_create_group(&dev_info->dev.kobj,
 689                                          &dev_info->event_attrs[i]);
 690                 if (ret) {
 691                         dev_err(&dev_info->dev,
 692                                 "Failed to register sysfs for event attrs");
 693                         goto error_remove_sysfs_interfaces;
 694                 }
 695         }
 696
 697         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 698                 ret = __iio_add_event_config_attrs(dev_info, i);
 699                 if (ret)
 700                         goto error_unregister_config_attrs;
 701         }
 702
 703         return 0;
 704
 705 error_unregister_config_attrs:
 706         for (j = 0; j < i; j++)
 707                 __iio_remove_event_config_attrs(dev_info, i);
 708         i = dev_info->num_interrupt_lines - 1;
 709 error_remove_sysfs_interfaces:
 710         for (j = 0; j < i; j++)
 711                 sysfs_remove_group(&dev_info->dev.kobj,
 712                                    &dev_info->event_attrs[j]);
 713         i = dev_info->num_interrupt_lines - 1;
 714 error_free_setup_ev_ints:
 715         for (j = 0; j < i; j++) {
 716                 iio_free_idr_val(&iio_event_idr,
 717                                  dev_info->event_interfaces[i].id);
 718                 iio_free_ev_int(&dev_info->event_interfaces[j]);
 719         }
 720         kfree(dev_info->interrupts);
 721 error_free_event_interfaces:
 722         kfree(dev_info->event_interfaces);
 723 error_ret:
 724
 725         return ret;
 726 }
 727
 728 static void iio_device_unregister_eventset(struct iio_dev *dev_info)
 729 {
 730         int i;
 731
 732         if (dev_info->num_interrupt_lines == 0)
 733                 return;
 734         for (i = 0; i < dev_info->num_interrupt_lines; i++)
 735                 sysfs_remove_group(&dev_info->dev.kobj,
 736                                    &dev_info->event_attrs[i]);
 737
 738         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 739                 iio_free_idr_val(&iio_event_idr,
 740                                  dev_info->event_interfaces[i].id);
 741                 iio_free_ev_int(&dev_info->event_interfaces[i]);
 742         }
 743         kfree(dev_info->interrupts);
 744         kfree(dev_info->event_interfaces);
 745 }
 746
 747 static void iio_dev_release(struct device *device)
 748 {
 749         struct iio_dev *dev = to_iio_dev(device);
 750
 751         iio_put();
 752         kfree(dev);
 753 }
 754
 755 static struct device_type iio_dev_type = {
 756         .name = "iio_device",
 757         .release = iio_dev_release,
 758 };
 759
 760 struct iio_dev *iio_allocate_device(void)
 761 {
 762         struct iio_dev *dev = kzalloc(sizeof *dev, GFP_KERNEL);
 763
 764         if (dev) {
 765                 dev->dev.type = &iio_dev_type;
 766                 dev->dev.class = &iio_class;
 767                 device_initialize(&dev->dev);
 768                 dev_set_drvdata(&dev->dev, (void *)dev);
 769                 mutex_init(&dev->mlock);
 770                 iio_get();
 771         }
 772
 773         return dev;
 774 }
 775 EXPORT_SYMBOL(iio_allocate_device);
 776
 777 void iio_free_device(struct iio_dev *dev)
 778 {
 779         if (dev)
 780                 iio_put_device(dev);
 781 }
 782 EXPORT_SYMBOL(iio_free_device);
 783
 784 int iio_device_register(struct iio_dev *dev_info)
 785 {
 786         int ret;
 787
 788         ret = iio_device_register_id(dev_info, &iio_idr);
 789         if (ret) {
 790                 dev_err(&dev_info->dev, "Failed to get id\n");
 791                 goto error_ret;
 792         }
 793         dev_set_name(&dev_info->dev, "device%d", dev_info->id);
 794
 795         ret = device_add(&dev_info->dev);
 796         if (ret)
 797                 goto error_free_idr;
 798         ret = iio_device_register_sysfs(dev_info);
 799         if (ret) {
 800                 dev_err(dev_info->dev.parent,
 801                         "Failed to register sysfs interfaces\n");
 802                 goto error_del_device;
 803         }
 804         ret = iio_device_register_eventset(dev_info);
 805         if (ret) {
 806                 dev_err(dev_info->dev.parent,
 807                         "Failed to register event set \n");
 808                 goto error_free_sysfs;
 809         }
 810         if (dev_info->modes & INDIO_RING_TRIGGERED)
 811                 iio_device_register_trigger_consumer(dev_info);
 812
 813         return 0;
 814
 815 error_free_sysfs:
 816         iio_device_unregister_sysfs(dev_info);
 817 error_del_device:
 818         device_del(&dev_info->dev);
 819 error_free_idr:
 820         iio_device_unregister_id(dev_info);
 821 error_ret:
 822         return ret;
 823 }
 824 EXPORT_SYMBOL(iio_device_register);
 825
 826 void iio_device_unregister(struct iio_dev *dev_info)
 827 {
 828         if (dev_info->modes & INDIO_RING_TRIGGERED)
 829                 iio_device_unregister_trigger_consumer(dev_info);
 830         iio_device_unregister_eventset(dev_info);
 831         iio_device_unregister_sysfs(dev_info);
 832         iio_device_unregister_id(dev_info);
 833         device_unregister(&dev_info->dev);
 834 }
 835 EXPORT_SYMBOL(iio_device_unregister);
 836
 837 void iio_put(void)
 838 {
 839         module_put(THIS_MODULE);
 840 }
 841
 842 void iio_get(void)
 843 {
 844         __module_get(THIS_MODULE);
 845 }
 846
 847 subsys_initcall(iio_init);
 848 module_exit(iio_exit);
 849
 850 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 851 MODULE_DESCRIPTION("Industrial I/O core");
 852 MODULE_LICENSE("GPL");