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Sourcecode: wacom-tools version File versions

hiddev.c

/*
 *  Copyright (c) 2001 Paul Stewart
 *  Copyright (c) 2001 Vojtech Pavlik
 *
 *  HID char devices, giving access to raw HID device events.
 *
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
 */

#include <linux/autoconf.h>
#if defined(CONFIG_MODVERSIONS) && !defined(MODVERSIONS)
#   define MODVERSIONS
#endif

#ifdef MODVERSIONS
#include <linux/modversions.h>
#endif

#define HIDDEV_MINOR_BASE     96
#define HIDDEV_MINORS         16
#define HIDDEV_BUFFER_SIZE    64

#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/input.h>
#include <linux/usb.h>
#include "hid.h"
#include <linux/hiddev.h>

struct hiddev {
      int exist;
      int open;
      int minor;
      wait_queue_head_t wait;
      devfs_handle_t devfs;
      struct hid_device *hid;
      struct hiddev_list *list;
};

struct hiddev_list {
      struct hiddev_event buffer[HIDDEV_BUFFER_SIZE];
      int head;
      int tail;
      struct fasync_struct *fasync;
      struct hiddev *hiddev;
      struct hiddev_list *next;
};

static struct hiddev *hiddev_table[HIDDEV_MINORS];
static devfs_handle_t hiddev_devfs_handle;

/*
 * Find a report, given the report's type and ID.  The ID can be specified
 * indirectly by REPORT_ID_FIRST (which returns the first report of the given
 * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
 * given type which follows old_id.
 */
static struct hid_report *
hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
{
      struct hid_report_enum *report_enum;
      struct list_head *list;

      if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
          rinfo->report_type > HID_REPORT_TYPE_MAX) return NULL;

      report_enum = hid->report_enum +
            (rinfo->report_type - HID_REPORT_TYPE_MIN);
      if ((rinfo->report_id & ~HID_REPORT_ID_MASK) != 0) {
            switch (rinfo->report_id & ~HID_REPORT_ID_MASK) {
            case HID_REPORT_ID_FIRST:
                  list = report_enum->report_list.next;
                  if (list == &report_enum->report_list) return NULL;
                  rinfo->report_id = ((struct hid_report *) list)->id;
                  break;

            case HID_REPORT_ID_NEXT:
                  list = (struct list_head *)
                        report_enum->report_id_hash[rinfo->report_id &
                                             HID_REPORT_ID_MASK];
                  if (list == NULL) return NULL;
                  list = list->next;
                  if (list == &report_enum->report_list) return NULL;
                  rinfo->report_id = ((struct hid_report *) list)->id;
                  break;

            default:
                  return NULL;
            }
      }

      return report_enum->report_id_hash[rinfo->report_id];
}

/*
 * Perform an exhaustive search of the report table for a usage, given its
 * type and usage id.
 */
static struct hid_field *
hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
{
      int i, j;
      struct hid_report *report;
      struct hid_report_enum *report_enum;
      struct list_head *list;
      struct hid_field *field;

      if (uref->report_type < HID_REPORT_TYPE_MIN ||
          uref->report_type > HID_REPORT_TYPE_MAX) return NULL;

      report_enum = hid->report_enum +
            (uref->report_type - HID_REPORT_TYPE_MIN);
      list = report_enum->report_list.next;
      while (list != &report_enum->report_list) {
            report = (struct hid_report *) list;
            for (i = 0; i < report->maxfield; i++) {
                  field = report->field[i];
                  for (j = 0; j < field->maxusage; j++) {
                        if (field->usage[j].hid == uref->usage_code) {
                              uref->report_id = report->id;
                              uref->field_index = i;
                              uref->usage_index = j;
                              return field;
                        }
                  }
            }
            list = list->next;
      }

      return NULL;
}

/*
 * This is where hid.c calls into hiddev to pass an event that occurred over
 * the interrupt pipe
 */
void hiddev_hid_event(struct hid_device *hid, unsigned int usage, int value)
{
      struct hiddev *hiddev = hid->hiddev;
      struct hiddev_list *list = hiddev->list;

      while (list) {
            list->buffer[list->head].hid = usage;
            list->buffer[list->head].value = value;
            list->head = (list->head + 1) & (HIDDEV_BUFFER_SIZE - 1);

            kill_fasync(&list->fasync, SIGIO, POLL_IN);

            list = list->next;
      }

      wake_up_interruptible(&hiddev->wait);
}

/*
 * fasync file op
 */
static int hiddev_fasync(int fd, struct file *file, int on)
{
      int retval;
      struct hiddev_list *list = file->private_data;
      retval = fasync_helper(fd, file, on, &list->fasync);
      return retval < 0 ? retval : 0;
}

/*
 * De-allocate a hiddev structure
 */
static void hiddev_cleanup(struct hiddev *hiddev)
{
      devfs_unregister(hiddev->devfs);
      hiddev_table[hiddev->minor] = NULL;
      kfree(hiddev);
}

/*
 * release file op
 */
static int hiddev_release(struct inode * inode, struct file * file)
{
      struct hiddev_list *list = file->private_data;
      struct hiddev_list **listptr;

      lock_kernel();
      listptr = &list->hiddev->list;
      hiddev_fasync(-1, file, 0);

      while (*listptr && (*listptr != list))
            listptr = &((*listptr)->next);
      *listptr = (*listptr)->next;

      if (!--list->hiddev->open) {
            if (list->hiddev->exist) 
                  hid_close(list->hiddev->hid);
            else
                  hiddev_cleanup(list->hiddev);
      }

      kfree(list);
      unlock_kernel();

      return 0;
}

/*
 * open file op
 */
static int hiddev_open(struct inode * inode, struct file * file) {
      struct hiddev_list *list;

      int i = MINOR(inode->i_rdev) - HIDDEV_MINOR_BASE;

      if (i >= HIDDEV_MINORS || !hiddev_table[i])
            return -ENODEV;

      if (!(list = kmalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
            return -ENOMEM;
      memset(list, 0, sizeof(struct hiddev_list));

      list->hiddev = hiddev_table[i];
      list->next = hiddev_table[i]->list;
      hiddev_table[i]->list = list;

      file->private_data = list;

      if (!list->hiddev->open++)
            if (list->hiddev->exist)
                  hid_open(hiddev_table[i]->hid);

      return 0;
}

/*
 * "write" file op
 */
static ssize_t hiddev_write(struct file * file, const char * buffer,
                      size_t count, loff_t *ppos)
{
      return -EINVAL;
}

/*
 * "read" file op
 */
static ssize_t hiddev_read(struct file * file, char * buffer, size_t count,
                     loff_t *ppos)
{
      DECLARE_WAITQUEUE(wait, current);
      struct hiddev_list *list = file->private_data;
      int retval = 0;

      if (list->head == list->tail) {

            add_wait_queue(&list->hiddev->wait, &wait);
            set_current_state(TASK_INTERRUPTIBLE);

            while (list->head == list->tail) {

                  if (file->f_flags & O_NONBLOCK) {
                        retval = -EAGAIN;
                        break;
                  }
                  if (signal_pending(current)) {
                        retval = -ERESTARTSYS;
                        break;
                  }
                  if (!list->hiddev->exist) {
                        retval = -EIO;
                        break;
                  }

                  schedule();
            }

            set_current_state(TASK_RUNNING);
            remove_wait_queue(&list->hiddev->wait, &wait);
      }

      if (retval)
            return retval;

      while (list->head != list->tail && retval + sizeof(struct hiddev_event) <= count) {
            if (copy_to_user(buffer + retval, list->buffer + list->tail,
                         sizeof(struct hiddev_event))) return -EFAULT;
            list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
            retval += sizeof(struct hiddev_event);
      }

      return retval;
}

/*
 * "poll" file op
 * No kernel lock - fine
 */
static unsigned int hiddev_poll(struct file *file, poll_table *wait)
{
      struct hiddev_list *list = file->private_data;
      poll_wait(file, &list->hiddev->wait, wait);
      if (list->head != list->tail)
            return POLLIN | POLLRDNORM;
      if (!list->hiddev->exist)
            return POLLERR | POLLHUP;
      return 0;
}

#define GET_TIMEOUT 3
#define SET_TIMEOUT 3

/*
 * "ioctl" file op
 */
static int hiddev_ioctl(struct inode *inode, struct file *file,
                  unsigned int cmd, unsigned long arg)
{
      struct hiddev_list *list = file->private_data;
      struct hiddev *hiddev = list->hiddev;
      struct hid_device *hid = hiddev->hid;
      struct usb_device *dev = hid->dev;
      struct hiddev_report_info rinfo;
      struct hiddev_usage_ref uref;
      struct hid_report *report;
      struct hid_field *field;

      if (!hiddev->exist) return -EIO;

      switch (cmd) {

      case HIDIOCGVERSION:
            return put_user(HID_VERSION, (int *) arg);

      case HIDIOCAPPLICATION:
            if (arg < 0 || arg >= hid->maxapplication)
                  return -EINVAL;
            return hid->application[arg];

      case HIDIOCGDEVINFO:
      {
            struct hiddev_devinfo dinfo;
            dinfo.bustype = BUS_USB;
            dinfo.busnum = dev->bus->busnum;
            dinfo.devnum = dev->devnum;
            dinfo.ifnum = hid->ifnum;
            dinfo.vendor = dev->descriptor.idVendor;
            dinfo.product = dev->descriptor.idProduct;
            dinfo.version = dev->descriptor.bcdDevice;
            dinfo.num_applications = hid->maxapplication;
            return copy_to_user((void *) arg, &dinfo, sizeof(dinfo));
      }

      case HIDIOCGSTRING:
            {
                  int idx, len;
                  char *buf;

                  if (get_user(idx, (int *) arg))
                        return -EFAULT;

                  if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
                        return -ENOMEM;

                  if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
                        kfree(buf);
                        return -EINVAL;
                  }

                  if (copy_to_user((void *) (arg+sizeof(int)), buf, len+1)) {
                        kfree(buf);
                        return -EFAULT;
                  }

                  kfree(buf);

                  return len;
            }

      case HIDIOCINITREPORT:

            hid_init_reports(hid);

            return 0;

      case HIDIOCGREPORT:
            if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
                  return -EFAULT;

            if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
                  return -EINVAL;

            if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                  return -EINVAL;

            hid_read_report(hid, report);

            return 0;

      case HIDIOCSREPORT:
            if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
                  return -EFAULT;

            if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
                  return -EINVAL;

            if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                  return -EINVAL;

            hid_write_report(hid, report);

            return 0;

      case HIDIOCGREPORTINFO:
            if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
                  return -EFAULT;

            if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                  return -EINVAL;

            rinfo.num_fields = report->maxfield;

            return copy_to_user((void *) arg, &rinfo, sizeof(rinfo));

      case HIDIOCGFIELDINFO:
      {
            struct hiddev_field_info finfo;
            if (copy_from_user(&finfo, (void *) arg, sizeof(finfo)))
                  return -EFAULT;
            rinfo.report_type = finfo.report_type;
            rinfo.report_id = finfo.report_id;
            if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                  return -EINVAL;

            if (finfo.field_index >= report->maxfield)
                  return -EINVAL;

            field = report->field[finfo.field_index];
            memset(&finfo, 0, sizeof(finfo));
            finfo.report_type = rinfo.report_type;
            finfo.report_id = rinfo.report_id;
            finfo.field_index = field->report_count - 1;
            finfo.maxusage = field->maxusage;
            finfo.flags = field->flags;
            finfo.physical = field->physical;
            finfo.logical = field->logical;
            finfo.application = field->application;
            finfo.logical_minimum = field->logical_minimum;
            finfo.logical_maximum = field->logical_maximum;
            finfo.physical_minimum = field->physical_minimum;
            finfo.physical_maximum = field->physical_maximum;
            finfo.unit_exponent = field->unit_exponent;
            finfo.unit = field->unit;

            return copy_to_user((void *) arg, &finfo, sizeof(finfo));
      }

      case HIDIOCGUCODE:
            if (copy_from_user(&uref, (void *) arg, sizeof(uref)))
                  return -EFAULT;

            rinfo.report_type = uref.report_type;
            rinfo.report_id = uref.report_id;
            if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                  return -EINVAL;

            if (uref.field_index >= report->maxfield)
                  return -EINVAL;

            field = report->field[uref.field_index];
            if (uref.usage_index >= field->maxusage)
                  return -EINVAL;

            uref.usage_code = field->usage[uref.usage_index].hid;

            return copy_to_user((void *) arg, &uref, sizeof(uref));

      case HIDIOCGUSAGE:
            if (copy_from_user(&uref, (void *) arg, sizeof(uref)))
                  return -EFAULT;

            if (uref.report_id == HID_REPORT_ID_UNKNOWN) {
                  field = hiddev_lookup_usage(hid, &uref);
                  if (field == NULL)
                        return -EINVAL;
            } else {
                  rinfo.report_type = uref.report_type;
                  rinfo.report_id = uref.report_id;
                  if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                        return -EINVAL;

                  if (uref.field_index >= report->maxfield)
                        return -EINVAL;

                  field = report->field[uref.field_index];
                  if (uref.usage_index >= field->maxusage)
                        return -EINVAL;
            }

            uref.value = field->value[uref.usage_index];

            return copy_to_user((void *) arg, &uref, sizeof(uref));

      case HIDIOCSUSAGE:
            if (copy_from_user(&uref, (void *) arg, sizeof(uref)))
                  return -EFAULT;

            if (uref.report_type == HID_REPORT_TYPE_INPUT)
                  return -EINVAL;

            if (uref.report_id == HID_REPORT_ID_UNKNOWN) {
                  field = hiddev_lookup_usage(hid, &uref);
                  if (field == NULL)
                        return -EINVAL;
            } else {
                  rinfo.report_type = uref.report_type;
                  rinfo.report_id = uref.report_id;
                  if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
                        return -EINVAL;

                  if (uref.field_index >= report->maxfield)
                        return -EINVAL;

                  field = report->field[uref.field_index];
                  if (uref.usage_index >= field->maxusage)
                        return -EINVAL;
            }

            field->value[uref.usage_index] = uref.value;

            return 0;

      default:

            if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
                  return -EINVAL;

            if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
                  int len;
                  if (!hid->name) return 0;
                  len = strlen(hid->name) + 1;
                  if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                  return copy_to_user((char *) arg, hid->name, len) ?
                        -EFAULT : len;
            }
      }
      return -EINVAL;
}

static struct file_operations hiddev_fops = {
      owner:            THIS_MODULE,
      read:       hiddev_read,
      write:            hiddev_write,
      poll:       hiddev_poll,
      open:       hiddev_open,
      release:    hiddev_release,
      ioctl:            hiddev_ioctl,
      fasync:           hiddev_fasync,
};

/*
 * This is where hid.c calls us to connect a hid device to the hiddev driver
 */
int hiddev_connect(struct hid_device *hid)
{
      struct hiddev *hiddev;
      int minor, i;
      char devfs_name[16];

      for (i = 0; i < hid->maxapplication; i++)
            if (!IS_INPUT_APPLICATION(hid->application[i]))
                  break;

      if (i == hid->maxapplication)
            return -1;

      for (minor = 0; minor < HIDDEV_MINORS && hiddev_table[minor]; minor++);
      if (minor == HIDDEV_MINORS) {
            printk(KERN_ERR "hiddev: no more free hiddev devices\n");
            return -1;
      }

      if (!(hiddev = kmalloc(sizeof(struct hiddev), GFP_KERNEL)))
            return -1;
      memset(hiddev, 0, sizeof(struct hiddev));

      init_waitqueue_head(&hiddev->wait);

      hiddev->minor = minor;
      hiddev_table[minor] = hiddev;

      hiddev->hid = hid;
      hiddev->exist = 1;

      sprintf(devfs_name, "hiddev%d", minor);
      hiddev->devfs = devfs_register(hiddev_devfs_handle, devfs_name,
                               DEVFS_FL_DEFAULT, USB_MAJOR,
                               minor + HIDDEV_MINOR_BASE,
                               S_IFCHR | S_IRUGO | S_IWUSR,
                               &hiddev_fops, NULL);
      hid->minor = minor;
      hid->hiddev = hiddev;

      return 0;
}

/*
 * This is where hid.c calls us to disconnect a hiddev device from the
 * corresponding hid device (usually because the usb device has disconnected)
 */
void hiddev_disconnect(struct hid_device *hid)
{
      struct hiddev *hiddev = hid->hiddev;

      hiddev->exist = 0;

      if (hiddev->open) {
            hid_close(hiddev->hid);
            wake_up_interruptible(&hiddev->wait);
      } else {
            hiddev_cleanup(hiddev);
      }
}

/* Currently this driver is a USB driver.  It's not a conventional one in
 * the sense that it doesn't probe at the USB level.  Instead it waits to
 * be connected by HID through the hiddev_connect / hiddev_disconnect
 * routines.  The reason to register as a USB device is to gain part of the
 * minor number space from the USB major.
 *
 * In theory, should the HID code be generalized to more than one physical
 * medium (say, IEEE 1384), this driver will probably need to register its
 * own major number, and in doing so, no longer need to register with USB.
 * At that point the probe routine and hiddev_driver struct below will no
 * longer be useful.
 */


/* We never attach in this manner, and rely on HID to connect us.  This
 * is why there is no disconnect routine defined in the usb_driver either.
 */
static void *hiddev_usbd_probe(struct usb_device *dev, unsigned int ifnum,
                    const struct usb_device_id *hiddev_info)
{
      return NULL;
}


static /* const */ struct usb_driver hiddev_driver = {
      name: "hiddev",
      probe:      hiddev_usbd_probe,
      fops: &hiddev_fops,
      minor:      HIDDEV_MINOR_BASE
};

int __init hiddev_init(void)
{
      hiddev_devfs_handle =
            devfs_mk_dir(devfs_find_handle(NULL, "usb", 0, 0, 0, 0), "hid", NULL);
      usb_register(&hiddev_driver);
      return 0;
}

void __exit hiddev_exit(void)
{
      devfs_unregister(hiddev_devfs_handle);
      usb_deregister(&hiddev_driver);
}

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