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