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_IDR(iio_idr);
  33
  34 /* IDR for general event identifiers */
  35 static DEFINE_IDR(iio_event_idr);
  36 /* IDR to allocate character device minor numbers */
  37 static DEFINE_IDR(iio_chrdev_idr);
  38 /* Lock used to protect both of the above */
  39 static DEFINE_SPINLOCK(iio_idr_lock);
  40
  41 dev_t iio_devt;
  42 EXPORT_SYMBOL(iio_devt);
  43
  44 #define IIO_DEV_MAX 256
  45 static char *iio_devnode(struct device *dev, mode_t *mode)
  46 {
  47         return kasprintf(GFP_KERNEL, "iio/%s", dev_name(dev));
  48 }
  49
  50 struct class iio_class = {
  51         .name = "iio",
  52         .devnode = iio_devnode,
  53 };
  54 EXPORT_SYMBOL(iio_class);
  55
  56 void __iio_change_event(struct iio_detected_event_list *ev,
  57                         int ev_code,
  58                         s64 timestamp)
  59 {
  60         ev->ev.id = ev_code;
  61         ev->ev.timestamp = timestamp;
  62 }
  63 EXPORT_SYMBOL(__iio_change_event);
  64
  65 /* Used both in the interrupt line put events and the ring buffer ones */
  66
  67 /* Note that in it's current form someone has to be listening before events
  68  * are queued. Hence a client MUST open the chrdev before the ring buffer is
  69  * switched on.
  70  */
  71  int __iio_push_event(struct iio_event_interface *ev_int,
  72                      int ev_code,
  73                      s64 timestamp,
  74                      struct iio_shared_ev_pointer *
  75                      shared_pointer_p)
  76 {
  77         struct iio_detected_event_list *ev;
  78         int ret = 0;
  79
  80         /* Does anyone care? */
  81         mutex_lock(&ev_int->event_list_lock);
  82         if (test_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags)) {
  83                 if (ev_int->current_events == ev_int->max_events) {
  84                         mutex_unlock(&ev_int->event_list_lock);
  85                         return 0;
  86                 }
  87                 ev = kmalloc(sizeof(*ev), GFP_KERNEL);
  88                 if (ev == NULL) {
  89                         ret = -ENOMEM;
  90                         mutex_unlock(&ev_int->event_list_lock);
  91                         goto error_ret;
  92                 }
  93                 ev->ev.id = ev_code;
  94                 ev->ev.timestamp = timestamp;
  95                 ev->shared_pointer = shared_pointer_p;
  96                 if (ev->shared_pointer)
  97                         shared_pointer_p->ev_p = ev;
  98
  99                 list_add_tail(&ev->list, &ev_int->det_events.list);
 100                 ev_int->current_events++;
 101                 mutex_unlock(&ev_int->event_list_lock);
 102                 wake_up_interruptible(&ev_int->wait);
 103         } else
 104                 mutex_unlock(&ev_int->event_list_lock);
 105
 106 error_ret:
 107         return ret;
 108 }
 109 EXPORT_SYMBOL(__iio_push_event);
 110
 111 int iio_push_event(struct iio_dev *dev_info,
 112                    int ev_line,
 113                    int ev_code,
 114                    s64 timestamp)
 115 {
 116         return __iio_push_event(&dev_info->event_interfaces[ev_line],
 117                                 ev_code, timestamp, NULL);
 118 }
 119 EXPORT_SYMBOL(iio_push_event);
 120
 121 /* Generic interrupt line interrupt handler */
 122 static irqreturn_t iio_interrupt_handler(int irq, void *_int_info)
 123 {
 124         struct iio_interrupt *int_info = _int_info;
 125         struct iio_dev *dev_info = int_info->dev_info;
 126         struct iio_event_handler_list *p;
 127         s64 time_ns;
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&int_info->ev_list_lock, flags);
 131         if (list_empty(&int_info->ev_list)) {
 132                 spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 133                 return IRQ_NONE;
 134         }
 135
 136         time_ns = iio_get_time_ns();
 137         /* detect single element list*/
 138         if (list_is_singular(&int_info->ev_list)) {
 139                 disable_irq_nosync(irq);
 140                 p = list_first_entry(&int_info->ev_list,
 141                                      struct iio_event_handler_list,
 142                                      list);
 143                 /* single event handler - maybe shared */
 144                 p->handler(dev_info, 1, time_ns, !(p->refcount > 1));
 145         } else
 146                 list_for_each_entry(p, &int_info->ev_list, list) {
 147                         disable_irq_nosync(irq);
 148                         p->handler(dev_info, 1, time_ns, 0);
 149                 }
 150         spin_unlock_irqrestore(&int_info->ev_list_lock, flags);
 151
 152         return IRQ_HANDLED;
 153 }
 154
 155 static struct iio_interrupt *iio_allocate_interrupt(void)
 156 {
 157         struct iio_interrupt *i = kmalloc(sizeof *i, GFP_KERNEL);
 158         if (i) {
 159                 spin_lock_init(&i->ev_list_lock);
 160                 INIT_LIST_HEAD(&i->ev_list);
 161         }
 162         return i;
 163 }
 164
 165 /* Confirming the validity of supplied irq is left to drivers.*/
 166 int iio_register_interrupt_line(unsigned int irq,
 167                                 struct iio_dev *dev_info,
 168                                 int line_number,
 169                                 unsigned long type,
 170                                 const char *name)
 171 {
 172         int ret;
 173
 174         dev_info->interrupts[line_number] = iio_allocate_interrupt();
 175         if (dev_info->interrupts[line_number] == NULL) {
 176                 ret = -ENOMEM;
 177                 goto error_ret;
 178         }
 179         dev_info->interrupts[line_number]->line_number = line_number;
 180         dev_info->interrupts[line_number]->irq = irq;
 181         dev_info->interrupts[line_number]->dev_info = dev_info;
 182
 183         /* Possibly only request on demand?
 184          * Can see this may complicate the handling of interrupts.
 185          * However, with this approach we might end up handling lots of
 186          * events no-one cares about.*/
 187         ret = request_irq(irq,
 188                           &iio_interrupt_handler,
 189                           type,
 190                           name,
 191                           dev_info->interrupts[line_number]);
 192
 193 error_ret:
 194         return ret;
 195 }
 196 EXPORT_SYMBOL(iio_register_interrupt_line);
 197
 198 /* This turns up an awful lot */
 199 ssize_t iio_read_const_attr(struct device *dev,
 200                             struct device_attribute *attr,
 201                             char *buf)
 202 {
 203         return sprintf(buf, "%s\n", to_iio_const_attr(attr)->string);
 204 }
 205 EXPORT_SYMBOL(iio_read_const_attr);
 206
 207 /* Before this runs the interrupt generator must have been disabled */
 208 void iio_unregister_interrupt_line(struct iio_dev *dev_info, int line_number)
 209 {
 210         /* make sure the interrupt handlers are all done */
 211         flush_scheduled_work();
 212         free_irq(dev_info->interrupts[line_number]->irq,
 213                  dev_info->interrupts[line_number]);
 214         kfree(dev_info->interrupts[line_number]);
 215 }
 216 EXPORT_SYMBOL(iio_unregister_interrupt_line);
 217
 218 /* Reference counted add and remove */
 219 void iio_add_event_to_list(struct iio_event_handler_list *el,
 220                           struct list_head *head)
 221 {
 222         unsigned long flags;
 223         struct iio_interrupt *inter = to_iio_interrupt(head);
 224
 225         /* take mutex to protect this element */
 226         mutex_lock(&el->exist_lock);
 227         if (el->refcount == 0) {
 228                 /* Take the event list spin lock */
 229                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 230                 list_add(&el->list, head);
 231                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 232         }
 233         el->refcount++;
 234         mutex_unlock(&el->exist_lock);
 235 }
 236 EXPORT_SYMBOL(iio_add_event_to_list);
 237
 238 void iio_remove_event_from_list(struct iio_event_handler_list *el,
 239                                struct list_head *head)
 240 {
 241         unsigned long flags;
 242         struct iio_interrupt *inter = to_iio_interrupt(head);
 243
 244         mutex_lock(&el->exist_lock);
 245         el->refcount--;
 246         if (el->refcount == 0) {
 247                 /* Take the event list spin lock */
 248                 spin_lock_irqsave(&inter->ev_list_lock, flags);
 249                 list_del_init(&el->list);
 250                 spin_unlock_irqrestore(&inter->ev_list_lock, flags);
 251         }
 252         mutex_unlock(&el->exist_lock);
 253 }
 254 EXPORT_SYMBOL(iio_remove_event_from_list);
 255
 256 static ssize_t iio_event_chrdev_read(struct file *filep,
 257                                      char __user *buf,
 258                                      size_t count,
 259                                      loff_t *f_ps)
 260 {
 261         struct iio_event_interface *ev_int = filep->private_data;
 262         struct iio_detected_event_list *el;
 263         int ret;
 264         size_t len;
 265
 266         mutex_lock(&ev_int->event_list_lock);
 267         if (list_empty(&ev_int->det_events.list)) {
 268                 if (filep->f_flags & O_NONBLOCK) {
 269                         ret = -EAGAIN;
 270                         goto error_mutex_unlock;
 271                 }
 272                 mutex_unlock(&ev_int->event_list_lock);
 273                 /* Blocking on device; waiting for something to be there */
 274                 ret = wait_event_interruptible(ev_int->wait,
 275                                                !list_empty(&ev_int
 276                                                            ->det_events.list));
 277                 if (ret)
 278                         goto error_ret;
 279                 /* Single access device so noone else can get the data */
 280                 mutex_lock(&ev_int->event_list_lock);
 281         }
 282
 283         el = list_first_entry(&ev_int->det_events.list,
 284                               struct iio_detected_event_list,
 285                               list);
 286         len = sizeof el->ev;
 287         if (copy_to_user(buf, &(el->ev), len)) {
 288                 ret = -EFAULT;
 289                 goto error_mutex_unlock;
 290         }
 291         list_del(&el->list);
 292         ev_int->current_events--;
 293         mutex_unlock(&ev_int->event_list_lock);
 294         /*
 295          * Possible concurency issue if an update of this event is on its way
 296          * through. May lead to new event being removed whilst the reported
 297          * event was the unescalated event. In typical use case this is not a
 298          * problem as userspace will say read half the buffer due to a 50%
 299          * full event which would make the correct 100% full incorrect anyway.
 300          */
 301         if (el->shared_pointer) {
 302                 spin_lock(&el->shared_pointer->lock);
 303                 (el->shared_pointer->ev_p) = NULL;
 304                 spin_unlock(&el->shared_pointer->lock);
 305         }
 306         kfree(el);
 307
 308         return len;
 309
 310 error_mutex_unlock:
 311         mutex_unlock(&ev_int->event_list_lock);
 312 error_ret:
 313
 314         return ret;
 315 }
 316
 317 static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 318 {
 319         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 320         struct iio_event_interface *ev_int = hand->private;
 321         struct iio_detected_event_list *el, *t;
 322
 323         mutex_lock(&ev_int->event_list_lock);
 324         clear_bit(IIO_BUSY_BIT_POS, &ev_int->handler.flags);
 325         /*
 326          * In order to maintain a clean state for reopening,
 327          * clear out any awaiting events. The mask will prevent
 328          * any new __iio_push_event calls running.
 329          */
 330         list_for_each_entry_safe(el, t, &ev_int->det_events.list, list) {
 331                 list_del(&el->list);
 332                 kfree(el);
 333         }
 334         mutex_unlock(&ev_int->event_list_lock);
 335
 336         return 0;
 337 }
 338
 339 static int iio_event_chrdev_open(struct inode *inode, struct file *filep)
 340 {
 341         struct iio_handler *hand = iio_cdev_to_handler(inode->i_cdev);
 342         struct iio_event_interface *ev_int = hand->private;
 343
 344         mutex_lock(&ev_int->event_list_lock);
 345         if (test_and_set_bit(IIO_BUSY_BIT_POS, &hand->flags)) {
 346                 fops_put(filep->f_op);
 347                 mutex_unlock(&ev_int->event_list_lock);
 348                 return -EBUSY;
 349         }
 350         filep->private_data = hand->private;
 351         mutex_unlock(&ev_int->event_list_lock);
 352
 353         return 0;
 354 }
 355
 356 static const struct file_operations iio_event_chrdev_fileops = {
 357         .read =  iio_event_chrdev_read,
 358         .release = iio_event_chrdev_release,
 359         .open = iio_event_chrdev_open,
 360         .owner = THIS_MODULE,
 361 };
 362
 363 static void iio_event_dev_release(struct device *dev)
 364 {
 365         struct iio_event_interface *ev_int
 366                 = container_of(dev, struct iio_event_interface, dev);
 367         cdev_del(&ev_int->handler.chrdev);
 368         iio_device_free_chrdev_minor(MINOR(dev->devt));
 369 };
 370
 371 static struct device_type iio_event_type = {
 372         .release = iio_event_dev_release,
 373 };
 374
 375 int iio_device_get_chrdev_minor(void)
 376 {
 377         int ret, val;
 378
 379 idr_again:
 380         if (unlikely(idr_pre_get(&iio_chrdev_idr, GFP_KERNEL) == 0))
 381                 return -ENOMEM;
 382         spin_lock(&iio_idr_lock);
 383         ret = idr_get_new(&iio_chrdev_idr, NULL, &val);
 384         spin_unlock(&iio_idr_lock);
 385         if (unlikely(ret == -EAGAIN))
 386                 goto idr_again;
 387         else if (unlikely(ret))
 388                 return ret;
 389         if (val > IIO_DEV_MAX)
 390                 return -ENOMEM;
 391         return val;
 392 }
 393
 394 void iio_device_free_chrdev_minor(int val)
 395 {
 396         spin_lock(&iio_idr_lock);
 397         idr_remove(&iio_chrdev_idr, val);
 398         spin_unlock(&iio_idr_lock);
 399 }
 400
 401 int iio_setup_ev_int(struct iio_event_interface *ev_int,
 402                      const char *name,
 403                      struct module *owner,
 404                      struct device *dev)
 405 {
 406         int ret, minor;
 407
 408         ev_int->dev.class = &iio_class;
 409         ev_int->dev.parent = dev;
 410         ev_int->dev.type = &iio_event_type;
 411         device_initialize(&ev_int->dev);
 412
 413         minor = iio_device_get_chrdev_minor();
 414         if (minor < 0) {
 415                 ret = minor;
 416                 goto error_device_put;
 417         }
 418         ev_int->dev.devt = MKDEV(MAJOR(iio_devt), minor);
 419         dev_set_name(&ev_int->dev, "%s", name);
 420
 421         ret = device_add(&ev_int->dev);
 422         if (ret)
 423                 goto error_free_minor;
 424
 425         cdev_init(&ev_int->handler.chrdev, &iio_event_chrdev_fileops);
 426         ev_int->handler.chrdev.owner = owner;
 427
 428         mutex_init(&ev_int->event_list_lock);
 429         /* discussion point - make this variable? */
 430         ev_int->max_events = 10;
 431         ev_int->current_events = 0;
 432         INIT_LIST_HEAD(&ev_int->det_events.list);
 433         init_waitqueue_head(&ev_int->wait);
 434         ev_int->handler.private = ev_int;
 435         ev_int->handler.flags = 0;
 436
 437         ret = cdev_add(&ev_int->handler.chrdev, ev_int->dev.devt, 1);
 438         if (ret)
 439                 goto error_unreg_device;
 440
 441         return 0;
 442
 443 error_unreg_device:
 444         device_unregister(&ev_int->dev);
 445 error_free_minor:
 446         iio_device_free_chrdev_minor(minor);
 447 error_device_put:
 448         put_device(&ev_int->dev);
 449
 450         return ret;
 451 }
 452
 453 void iio_free_ev_int(struct iio_event_interface *ev_int)
 454 {
 455         device_unregister(&ev_int->dev);
 456         put_device(&ev_int->dev);
 457 }
 458
 459 static int __init iio_dev_init(void)
 460 {
 461         int err;
 462
 463         err = alloc_chrdev_region(&iio_devt, 0, IIO_DEV_MAX, "iio");
 464         if (err < 0)
 465                 printk(KERN_ERR "%s: failed to allocate char dev region\n",
 466                        __FILE__);
 467
 468         return err;
 469 }
 470
 471 static void __exit iio_dev_exit(void)
 472 {
 473         if (iio_devt)
 474                 unregister_chrdev_region(iio_devt, IIO_DEV_MAX);
 475 }
 476
 477 static int __init iio_init(void)
 478 {
 479         int ret;
 480
 481         /* Create sysfs class */
 482         ret  = class_register(&iio_class);
 483         if (ret < 0) {
 484                 printk(KERN_ERR
 485                        "%s could not create sysfs class\n",
 486                         __FILE__);
 487                 goto error_nothing;
 488         }
 489
 490         ret = iio_dev_init();
 491         if (ret < 0)
 492                 goto error_unregister_class;
 493
 494         return 0;
 495
 496 error_unregister_class:
 497         class_unregister(&iio_class);
 498 error_nothing:
 499         return ret;
 500 }
 501
 502 static void __exit iio_exit(void)
 503 {
 504         iio_dev_exit();
 505         class_unregister(&iio_class);
 506 }
 507
 508 static int iio_device_register_sysfs(struct iio_dev *dev_info)
 509 {
 510         int ret = 0;
 511
 512         ret = sysfs_create_group(&dev_info->dev.kobj, dev_info->attrs);
 513         if (ret) {
 514                 dev_err(dev_info->dev.parent,
 515                         "Failed to register sysfs hooks\n");
 516                 goto error_ret;
 517         }
 518
 519         if (dev_info->scan_el_attrs) {
 520                 ret = sysfs_create_group(&dev_info->dev.kobj,
 521                                          dev_info->scan_el_attrs);
 522                 if (ret)
 523                         dev_err(&dev_info->dev,
 524                                 "Failed to add sysfs scan els\n");
 525         }
 526
 527 error_ret:
 528         return ret;
 529 }
 530
 531 static void iio_device_unregister_sysfs(struct iio_dev *dev_info)
 532 {
 533         if (dev_info->scan_el_attrs)
 534                 sysfs_remove_group(&dev_info->dev.kobj,
 535                                    dev_info->scan_el_attrs);
 536
 537         sysfs_remove_group(&dev_info->dev.kobj, dev_info->attrs);
 538 }
 539
 540 /* Return a negative errno on failure */
 541 int iio_get_new_idr_val(struct idr *this_idr)
 542 {
 543         int ret;
 544         int val;
 545
 546 idr_again:
 547         if (unlikely(idr_pre_get(this_idr, GFP_KERNEL) == 0))
 548                 return -ENOMEM;
 549
 550         spin_lock(&iio_idr_lock);
 551         ret = idr_get_new(this_idr, NULL, &val);
 552         spin_unlock(&iio_idr_lock);
 553         if (unlikely(ret == -EAGAIN))
 554                 goto idr_again;
 555         else if (unlikely(ret))
 556                 return ret;
 557
 558         return val;
 559 }
 560 EXPORT_SYMBOL(iio_get_new_idr_val);
 561
 562 void iio_free_idr_val(struct idr *this_idr, int id)
 563 {
 564         spin_lock(&iio_idr_lock);
 565         idr_remove(this_idr, id);
 566         spin_unlock(&iio_idr_lock);
 567 }
 568 EXPORT_SYMBOL(iio_free_idr_val);
 569
 570 static int iio_device_register_id(struct iio_dev *dev_info,
 571                                   struct idr *this_idr)
 572 {
 573
 574         dev_info->id = iio_get_new_idr_val(&iio_idr);
 575         if (dev_info->id < 0)
 576                 return dev_info->id;
 577         return 0;
 578 }
 579
 580 static void iio_device_unregister_id(struct iio_dev *dev_info)
 581 {
 582         iio_free_idr_val(&iio_idr, dev_info->id);
 583 }
 584
 585 static inline int __iio_add_event_config_attrs(struct iio_dev *dev_info, int i)
 586 {
 587         int ret;
 588         /*p for adding, q for removing */
 589         struct attribute **attrp, **attrq;
 590
 591         if (dev_info->event_conf_attrs && dev_info->event_conf_attrs[i].attrs) {
 592                 attrp = dev_info->event_conf_attrs[i].attrs;
 593                 while (*attrp) {
 594                         ret =  sysfs_add_file_to_group(&dev_info->dev.kobj,
 595                                                        *attrp,
 596                                                        dev_info
 597                                                        ->event_attrs[i].name);
 598                         if (ret)
 599                                 goto error_ret;
 600                         attrp++;
 601                 }
 602         }
 603         return 0;
 604
 605 error_ret:
 606         attrq = dev_info->event_conf_attrs[i].attrs;
 607         while (attrq != attrp) {
 608                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 609                                              *attrq,
 610                                              dev_info->event_attrs[i].name);
 611                 attrq++;
 612         }
 613
 614         return ret;
 615 }
 616
 617 static inline int __iio_remove_event_config_attrs(struct iio_dev *dev_info,
 618                                                   int i)
 619 {
 620         struct attribute **attrq;
 621
 622         if (dev_info->event_conf_attrs
 623                 && dev_info->event_conf_attrs[i].attrs) {
 624                 attrq = dev_info->event_conf_attrs[i].attrs;
 625                 while (*attrq) {
 626                         sysfs_remove_file_from_group(&dev_info->dev.kobj,
 627                                                      *attrq,
 628                                                      dev_info
 629                                                      ->event_attrs[i].name);
 630                         attrq++;
 631                 }
 632         }
 633
 634         return 0;
 635 }
 636
 637 static int iio_device_register_eventset(struct iio_dev *dev_info)
 638 {
 639         int ret = 0, i, j;
 640
 641         if (dev_info->num_interrupt_lines == 0)
 642                 return 0;
 643
 644         dev_info->event_interfaces =
 645                 kzalloc(sizeof(struct iio_event_interface)
 646                         *dev_info->num_interrupt_lines,
 647                         GFP_KERNEL);
 648         if (dev_info->event_interfaces == NULL) {
 649                 ret = -ENOMEM;
 650                 goto error_ret;
 651         }
 652
 653         dev_info->interrupts = kzalloc(sizeof(struct iio_interrupt *)
 654                                        *dev_info->num_interrupt_lines,
 655                                        GFP_KERNEL);
 656         if (dev_info->interrupts == NULL) {
 657                 ret = -ENOMEM;
 658                 goto error_free_event_interfaces;
 659         }
 660
 661         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 662                 dev_info->event_interfaces[i].owner = dev_info->driver_module;
 663                 ret = iio_get_new_idr_val(&iio_event_idr);
 664                 if (ret < 0)
 665                         goto error_free_setup_ev_ints;
 666                 else
 667                         dev_info->event_interfaces[i].id = ret;
 668
 669                 snprintf(dev_info->event_interfaces[i]._name, 20,
 670                          "event_line%d",
 671                         dev_info->event_interfaces[i].id);
 672
 673                 ret = iio_setup_ev_int(&dev_info->event_interfaces[i],
 674                                        (const char *)(dev_info
 675                                                       ->event_interfaces[i]
 676                                                       ._name),
 677                                        dev_info->driver_module,
 678                                        &dev_info->dev);
 679                 if (ret) {
 680                         dev_err(&dev_info->dev,
 681                                 "Could not get chrdev interface\n");
 682                         iio_free_idr_val(&iio_event_idr,
 683                                          dev_info->event_interfaces[i].id);
 684                         goto error_free_setup_ev_ints;
 685                 }
 686         }
 687
 688         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 689                 snprintf(dev_info->event_interfaces[i]._attrname, 20,
 690                         "event_line%d_sources", i);
 691                 dev_info->event_attrs[i].name
 692                         = (const char *)
 693                         (dev_info->event_interfaces[i]._attrname);
 694                 ret = sysfs_create_group(&dev_info->dev.kobj,
 695                                          &dev_info->event_attrs[i]);
 696                 if (ret) {
 697                         dev_err(&dev_info->dev,
 698                                 "Failed to register sysfs for event attrs");
 699                         goto error_remove_sysfs_interfaces;
 700                 }
 701         }
 702
 703         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 704                 ret = __iio_add_event_config_attrs(dev_info, i);
 705                 if (ret)
 706                         goto error_unregister_config_attrs;
 707         }
 708
 709         return 0;
 710
 711 error_unregister_config_attrs:
 712         for (j = 0; j < i; j++)
 713                 __iio_remove_event_config_attrs(dev_info, i);
 714         i = dev_info->num_interrupt_lines - 1;
 715 error_remove_sysfs_interfaces:
 716         for (j = 0; j < i; j++)
 717                 sysfs_remove_group(&dev_info->dev.kobj,
 718                                    &dev_info->event_attrs[j]);
 719         i = dev_info->num_interrupt_lines - 1;
 720 error_free_setup_ev_ints:
 721         for (j = 0; j < i; j++) {
 722                 iio_free_idr_val(&iio_event_idr,
 723                                  dev_info->event_interfaces[i].id);
 724                 iio_free_ev_int(&dev_info->event_interfaces[j]);
 725         }
 726         kfree(dev_info->interrupts);
 727 error_free_event_interfaces:
 728         kfree(dev_info->event_interfaces);
 729 error_ret:
 730
 731         return ret;
 732 }
 733
 734 static void iio_device_unregister_eventset(struct iio_dev *dev_info)
 735 {
 736         int i;
 737
 738         if (dev_info->num_interrupt_lines == 0)
 739                 return;
 740         for (i = 0; i < dev_info->num_interrupt_lines; i++)
 741                 sysfs_remove_group(&dev_info->dev.kobj,
 742                                    &dev_info->event_attrs[i]);
 743
 744         for (i = 0; i < dev_info->num_interrupt_lines; i++) {
 745                 iio_free_idr_val(&iio_event_idr,
 746                                  dev_info->event_interfaces[i].id);
 747                 iio_free_ev_int(&dev_info->event_interfaces[i]);
 748         }
 749         kfree(dev_info->interrupts);
 750         kfree(dev_info->event_interfaces);
 751 }
 752
 753 static void iio_dev_release(struct device *device)
 754 {
 755         struct iio_dev *dev = to_iio_dev(device);
 756
 757         iio_put();
 758         kfree(dev);
 759 }
 760
 761 static struct device_type iio_dev_type = {
 762         .name = "iio_device",
 763         .release = iio_dev_release,
 764 };
 765
 766 struct iio_dev *iio_allocate_device(void)
 767 {
 768         struct iio_dev *dev = kzalloc(sizeof *dev, GFP_KERNEL);
 769
 770         if (dev) {
 771                 dev->dev.type = &iio_dev_type;
 772                 dev->dev.class = &iio_class;
 773                 device_initialize(&dev->dev);
 774                 dev_set_drvdata(&dev->dev, (void *)dev);
 775                 mutex_init(&dev->mlock);
 776                 iio_get();
 777         }
 778
 779         return dev;
 780 }
 781 EXPORT_SYMBOL(iio_allocate_device);
 782
 783 void iio_free_device(struct iio_dev *dev)
 784 {
 785         if (dev)
 786                 iio_put_device(dev);
 787 }
 788 EXPORT_SYMBOL(iio_free_device);
 789
 790 int iio_device_register(struct iio_dev *dev_info)
 791 {
 792         int ret;
 793
 794         ret = iio_device_register_id(dev_info, &iio_idr);
 795         if (ret) {
 796                 dev_err(&dev_info->dev, "Failed to get id\n");
 797                 goto error_ret;
 798         }
 799         dev_set_name(&dev_info->dev, "device%d", dev_info->id);
 800
 801         ret = device_add(&dev_info->dev);
 802         if (ret)
 803                 goto error_free_idr;
 804         ret = iio_device_register_sysfs(dev_info);
 805         if (ret) {
 806                 dev_err(dev_info->dev.parent,
 807                         "Failed to register sysfs interfaces\n");
 808                 goto error_del_device;
 809         }
 810         ret = iio_device_register_eventset(dev_info);
 811         if (ret) {
 812                 dev_err(dev_info->dev.parent,
 813                         "Failed to register event set \n");
 814                 goto error_free_sysfs;
 815         }
 816         if (dev_info->modes & INDIO_RING_TRIGGERED)
 817                 iio_device_register_trigger_consumer(dev_info);
 818
 819         return 0;
 820
 821 error_free_sysfs:
 822         iio_device_unregister_sysfs(dev_info);
 823 error_del_device:
 824         device_del(&dev_info->dev);
 825 error_free_idr:
 826         iio_device_unregister_id(dev_info);
 827 error_ret:
 828         return ret;
 829 }
 830 EXPORT_SYMBOL(iio_device_register);
 831
 832 void iio_device_unregister(struct iio_dev *dev_info)
 833 {
 834         if (dev_info->modes & INDIO_RING_TRIGGERED)
 835                 iio_device_unregister_trigger_consumer(dev_info);
 836         iio_device_unregister_eventset(dev_info);
 837         iio_device_unregister_sysfs(dev_info);
 838         iio_device_unregister_id(dev_info);
 839         device_unregister(&dev_info->dev);
 840 }
 841 EXPORT_SYMBOL(iio_device_unregister);
 842
 843 void iio_put(void)
 844 {
 845         module_put(THIS_MODULE);
 846 }
 847
 848 void iio_get(void)
 849 {
 850         __module_get(THIS_MODULE);
 851 }
 852
 853 subsys_initcall(iio_init);
 854 module_exit(iio_exit);
 855
 856 MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
 857 MODULE_DESCRIPTION("Industrial I/O core");
 858 MODULE_LICENSE("GPL");