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Sourcecode: wacom-tools version File versions

evdev.c

/*
 * Event char devices, giving access to raw input device events.
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#define EVDEV_MINOR_BASE      64
#define EVDEV_MINORS          32
#define EVDEV_BUFFER_SIZE     64

#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/major.h>
#include <linux/smp_lock.h>
#include <linux/device.h>
#include <linux/devfs_fs_kernel.h>

struct evdev {
      int exist;
      int open;
      int minor;
      char name[16];
      struct input_handle handle;
      wait_queue_head_t wait;
      struct evdev_list *grab;
      struct list_head list;
};

struct evdev_list {
      struct input_event buffer[EVDEV_BUFFER_SIZE];
      int head;
      int tail;
      struct fasync_struct *fasync;
      struct evdev *evdev;
      struct list_head node;
};

static struct evdev *evdev_table[EVDEV_MINORS];

static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
{
      struct evdev *evdev = handle->private;
      struct evdev_list *list;

      if (evdev->grab) {
            list = evdev->grab;

            do_gettimeofday(&list->buffer[list->head].time);
            list->buffer[list->head].type = type;
            list->buffer[list->head].code = code;
            list->buffer[list->head].value = value;
            list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);

            kill_fasync(&list->fasync, SIGIO, POLL_IN);
      } else
            list_for_each_entry(list, &evdev->list, node) {

                  do_gettimeofday(&list->buffer[list->head].time);
                  list->buffer[list->head].type = type;
                  list->buffer[list->head].code = code;
                  list->buffer[list->head].value = value;
                  list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);

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

      wake_up_interruptible(&evdev->wait);
}

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

static int evdev_flush(struct file * file)
{
      struct evdev_list *list = file->private_data;
      if (!list->evdev->exist) return -ENODEV;
      return input_flush_device(&list->evdev->handle, file);
}

static void evdev_free(struct evdev *evdev)
{
      devfs_remove("input/event%d", evdev->minor);
      class_simple_device_remove(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + evdev->minor));
      evdev_table[evdev->minor] = NULL;
      kfree(evdev);
}

static int evdev_release(struct inode * inode, struct file * file)
{
      struct evdev_list *list = file->private_data;

      if (list->evdev->grab == list) {
            input_release_device(&list->evdev->handle);
            list->evdev->grab = NULL;
      }

      evdev_fasync(-1, file, 0);
      list_del(&list->node);

      if (!--list->evdev->open) {
            if (list->evdev->exist)
                  input_close_device(&list->evdev->handle);
            else
                  evdev_free(list->evdev);
      }

      kfree(list);
      return 0;
}

static int evdev_open(struct inode * inode, struct file * file)
{
      struct evdev_list *list;
      int i = iminor(inode) - EVDEV_MINOR_BASE;
      int accept_err;

      if (i >= EVDEV_MINORS || !evdev_table[i])
            return -ENODEV;

      if ((accept_err = input_accept_process(&(evdev_table[i]->handle), file)))
            return accept_err;

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

      list->evdev = evdev_table[i];
      list_add_tail(&list->node, &evdev_table[i]->list);
      file->private_data = list;

      if (!list->evdev->open++)
            if (list->evdev->exist)
                  input_open_device(&list->evdev->handle);

      return 0;
}

static ssize_t evdev_write(struct file * file, const char * buffer, size_t count, loff_t *ppos)
{
      struct evdev_list *list = file->private_data;
      struct input_event event;
      int retval = 0;

      if (!list->evdev->exist) return -ENODEV;

      while (retval < count) {

            if (copy_from_user(&event, buffer + retval, sizeof(struct input_event)))
                  return -EFAULT;
            input_event(list->evdev->handle.dev, event.type, event.code, event.value);
            retval += sizeof(struct input_event);
      }

      return retval;
}

static ssize_t evdev_read(struct file * file, char * buffer, size_t count, loff_t *ppos)
{
      struct evdev_list *list = file->private_data;
      int retval;

      if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
            return -EAGAIN;

      retval = wait_event_interruptible(list->evdev->wait,
            list->head != list->tail && list->evdev->exist);

      if (retval)
            return retval;

      if (!list->evdev->exist)
            return -ENODEV;

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

      return retval;
}

/* No kernel lock - fine */
static unsigned int evdev_poll(struct file *file, poll_table *wait)
{
      struct evdev_list *list = file->private_data;
      poll_wait(file, &list->evdev->wait, wait);
      if (list->head != list->tail)
            return POLLIN | POLLRDNORM;
      return 0;
}

static int evdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
      struct evdev_list *list = file->private_data;
      struct evdev *evdev = list->evdev;
      struct input_dev *dev = evdev->handle.dev;
      struct input_absinfo abs;
      int i, t, u, v;

      if (!evdev->exist) return -ENODEV;

      switch (cmd) {

            case EVIOCGVERSION:
                  return put_user(EV_VERSION, (int *) arg);

            case EVIOCGID:
                  return copy_to_user((void *) arg, &dev->id, sizeof(struct input_id)) ? -EFAULT : 0;
            
            case EVIOCGKEYCODE:
                  if (get_user(t, ((int *) arg) + 0)) return -EFAULT;
                  if (t < 0 || t > dev->keycodemax || !dev->keycodesize) return -EINVAL;
                  if (put_user(INPUT_KEYCODE(dev, t), ((int *) arg) + 1)) return -EFAULT;
                  return 0;

            case EVIOCSKEYCODE:
                  if (get_user(t, ((int *) arg) + 0)) return -EFAULT;
                  if (t < 0 || t > dev->keycodemax || !dev->keycodesize) return -EINVAL;
                  if (get_user(v, ((int *) arg) + 1)) return -EFAULT;
                  u = SET_INPUT_KEYCODE(dev, t, v);
                  clear_bit(u, dev->keybit);
                  set_bit(v, dev->keybit);
                  for (i = 0; i < dev->keycodemax; i++)
                        if (INPUT_KEYCODE(dev,i) == u)
                              set_bit(u, dev->keybit);
                  return 0;

            case EVIOCSFF:
                  if (dev->upload_effect) {
                        struct ff_effect effect;
                        int err;

                        if (copy_from_user((void*)(&effect), (void*)arg, sizeof(effect)))
                              return -EFAULT;
                        err = dev->upload_effect(dev, &effect);
                        if (put_user(effect.id, &(((struct ff_effect*)arg)->id)))
                              return -EFAULT;
                        return err;
                  }
                  else return -ENOSYS;

            case EVIOCRMFF:
                  if (dev->erase_effect) {
                        return dev->erase_effect(dev, (int)arg);
                  }
                  else return -ENOSYS;

            case EVIOCGEFFECTS:
                  if (put_user(dev->ff_effects_max, (int*) arg))
                        return -EFAULT;
                  return 0;

            case EVIOCGRAB:
                  if (arg) {
                        if (evdev->grab)
                              return -EBUSY;
                        if (input_grab_device(&evdev->handle))
                              return -EBUSY;
                        evdev->grab = list;
                        return 0;
                  } else {
                        if (evdev->grab != list)
                              return -EINVAL;
                        input_release_device(&evdev->handle);
                        evdev->grab = NULL;
                        return 0;
                  }

            default:

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

                  if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {

                        long *bits;
                        int len;

                        switch (_IOC_NR(cmd) & EV_MAX) {
                              case      0: bits = dev->evbit;  len = EV_MAX;  break;
                              case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
                              case EV_REL: bits = dev->relbit; len = REL_MAX; break;
                              case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
                              case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
                              case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
                              case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
                              case EV_FF:  bits = dev->ffbit;  len = FF_MAX;  break;
                              default: return -EINVAL;
                        }
                        len = NBITS(len) * sizeof(long);
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, bits, len) ? -EFAULT : len;
                  }

                  if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) {
                        int len;
                        len = NBITS(KEY_MAX) * sizeof(long);
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, dev->key, len) ? -EFAULT : len;
                  }

                  if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) {
                        int len;
                        len = NBITS(LED_MAX) * sizeof(long);
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, dev->led, len) ? -EFAULT : len;
                  }

                  if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) {
                        int len;
                        len = NBITS(SND_MAX) * sizeof(long);
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, dev->snd, len) ? -EFAULT : len;
                  }

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

                  if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
                        int len;
                        if (!dev->phys) return -ENOENT;
                        len = strlen(dev->phys) + 1;
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, dev->phys, len) ? -EFAULT : len;
                  }

                  if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
                        int len;
                        if (!dev->uniq) return -ENOENT;
                        len = strlen(dev->uniq) + 1;
                        if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
                        return copy_to_user((char *) arg, dev->uniq, len) ? -EFAULT : len;
                  }

                  if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {

                        int t = _IOC_NR(cmd) & ABS_MAX;

                        abs.value = dev->abs[t];
                        abs.minimum = dev->absmin[t];
                        abs.maximum = dev->absmax[t];
                        abs.fuzz = dev->absfuzz[t];
                        abs.flat = dev->absflat[t];

                        if (copy_to_user((void *) arg, &abs, sizeof(struct input_absinfo)))
                              return -EFAULT;

                        return 0;
                  }

                  if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {

                        int t = _IOC_NR(cmd) & ABS_MAX;

                        if (copy_from_user(&abs, (void *) arg, sizeof(struct input_absinfo)))
                              return -EFAULT;

                        dev->abs[t] = abs.value;
                        dev->absmin[t] = abs.minimum;
                        dev->absmax[t] = abs.maximum;
                        dev->absfuzz[t] = abs.fuzz;
                        dev->absflat[t] = abs.flat;

                        return 0;
                  }
      }
      return -EINVAL;
}

static struct file_operations evdev_fops = {
      .owner =    THIS_MODULE,
      .read =           evdev_read,
      .write =    evdev_write,
      .poll =           evdev_poll,
      .open =           evdev_open,
      .release =  evdev_release,
      .ioctl =    evdev_ioctl,
      .fasync =   evdev_fasync,
      .flush =    evdev_flush
};

static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev, struct input_device_id *id)
{
      struct evdev *evdev;
      int minor;

      for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++) {
            if (!evdev_table[minor]->exist && evdev_table[minor]->open) /* reuse */
            {
                  evdev = evdev_table[minor];
                  evdev->handle.dev = dev;
                  evdev->handle.handler = handler;
                  evdev->handle.private = evdev; /* should already be */
                  evdev->exist = 1;
                  printk(KERN_INFO "evdev: reusing event%d for vendor/product 0x%x/0x%x\n", minor, dev->id.vendor, dev->id.product);
                  input_open_device(&evdev->handle);
                  wake_up_interruptible(&evdev->wait);
                  return &evdev->handle;
            }
      }

      if (minor == EVDEV_MINORS) {
            printk(KERN_ERR "evdev: no more free evdev devices\n");
            return NULL;
      }

      if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
            return NULL;
      memset(evdev, 0, sizeof(struct evdev));

      INIT_LIST_HEAD(&evdev->list);
      init_waitqueue_head(&evdev->wait);

      evdev->exist = 1;
      evdev->minor = minor;
      evdev->handle.dev = dev;
      evdev->handle.name = evdev->name;
      evdev->handle.handler = handler;
      evdev->handle.private = evdev;
      sprintf(evdev->name, "event%d", minor);

      evdev_table[minor] = evdev;

      devfs_mk_cdev(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
                  S_IFCHR|S_IRUGO|S_IWUSR, "input/event%d", minor);
      class_simple_device_add(input_class, 
                        MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
                        dev->dev, "event%d", minor);

      return &evdev->handle;
}

static void evdev_disconnect(struct input_handle *handle)
{
      struct evdev *evdev = handle->private;

      evdev->exist = 0;

      if (evdev->open) {
            input_close_device(handle);
            wake_up_interruptible(&evdev->wait);
      } else
            evdev_free(evdev);
}

static struct input_device_id evdev_ids[] = {
      { .driver_info = 1 },   /* Matches all devices */
      { },              /* Terminating zero entry */
};

MODULE_DEVICE_TABLE(input, evdev_ids);

static struct input_handler evdev_handler = {
      .event =    evdev_event,
      .connect =  evdev_connect,
      .disconnect =     evdev_disconnect,
      .fops =           &evdev_fops,
      .minor =    EVDEV_MINOR_BASE,
      .name =           "evdev",
      .id_table = evdev_ids,
};

static int __init evdev_init(void)
{
      input_register_handler(&evdev_handler);
      return 0;
}

static void __exit evdev_exit(void)
{
      input_unregister_handler(&evdev_handler);
}

module_init(evdev_init);
module_exit(evdev_exit);

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Input driver event char devices-2.6.5-pc0.1");
MODULE_LICENSE("GPL");

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