evdev.c

来自「linux 内核源代码」· C语言 代码 · 共 974 行 · 第 1/2 页

	struct evdev *evdev = client->evdev;

	poll_wait(file, &evdev->wait, wait);
	return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
		(evdev->exist ? 0 : (POLLHUP | POLLERR));
}

#ifdef CONFIG_COMPAT

#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
#define BITS_TO_LONGS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)

#ifdef __BIG_ENDIAN
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
			unsigned int maxlen, void __user *p, int compat)
{
	int len, i;

	if (compat) {
		len = BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t);
		if (len > maxlen)
			len = maxlen;

		for (i = 0; i < len / sizeof(compat_long_t); i++)
			if (copy_to_user((compat_long_t __user *) p + i,
					 (compat_long_t *) bits +
						i + 1 - ((i % 2) << 1),
					 sizeof(compat_long_t)))
				return -EFAULT;
	} else {
		len = BITS_TO_LONGS(maxbit) * sizeof(long);
		if (len > maxlen)
			len = maxlen;

		if (copy_to_user(p, bits, len))
			return -EFAULT;
	}

	return len;
}
#else
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
			unsigned int maxlen, void __user *p, int compat)
{
	int len = compat ?
			BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) :
			BITS_TO_LONGS(maxbit) * sizeof(long);

	if (len > maxlen)
		len = maxlen;

	return copy_to_user(p, bits, len) ? -EFAULT : len;
}
#endif /* __BIG_ENDIAN */

#else

static int bits_to_user(unsigned long *bits, unsigned int maxbit,
			unsigned int maxlen, void __user *p, int compat)
{
	int len = BITS_TO_LONGS(maxbit) * sizeof(long);

	if (len > maxlen)
		len = maxlen;

	return copy_to_user(p, bits, len) ? -EFAULT : len;
}

#endif /* CONFIG_COMPAT */

static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
{
	int len;

	if (!str)
		return -ENOENT;

	len = strlen(str) + 1;
	if (len > maxlen)
		len = maxlen;

	return copy_to_user(p, str, len) ? -EFAULT : len;
}

static long evdev_do_ioctl(struct file *file, unsigned int cmd,
			   void __user *p, int compat_mode)
{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	struct input_dev *dev = evdev->handle.dev;
	struct input_absinfo abs;
	struct ff_effect effect;
	int __user *ip = (int __user *)p;
	int i, t, u, v;
	int error;

	switch (cmd) {

	case EVIOCGVERSION:
		return put_user(EV_VERSION, ip);

	case EVIOCGID:
		if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
			return -EFAULT;
		return 0;

	case EVIOCGREP:
		if (!test_bit(EV_REP, dev->evbit))
			return -ENOSYS;
		if (put_user(dev->rep[REP_DELAY], ip))
			return -EFAULT;
		if (put_user(dev->rep[REP_PERIOD], ip + 1))
			return -EFAULT;
		return 0;

	case EVIOCSREP:
		if (!test_bit(EV_REP, dev->evbit))
			return -ENOSYS;
		if (get_user(u, ip))
			return -EFAULT;
		if (get_user(v, ip + 1))
			return -EFAULT;

		input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
		input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);

		return 0;

	case EVIOCGKEYCODE:
		if (get_user(t, ip))
			return -EFAULT;

		error = dev->getkeycode(dev, t, &v);
		if (error)
			return error;

		if (put_user(v, ip + 1))
			return -EFAULT;

		return 0;

	case EVIOCSKEYCODE:
		if (get_user(t, ip) || get_user(v, ip + 1))
			return -EFAULT;

		return dev->setkeycode(dev, t, v);

	case EVIOCSFF:
		if (copy_from_user(&effect, p, sizeof(effect)))
			return -EFAULT;

		error = input_ff_upload(dev, &effect, file);

		if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
			return -EFAULT;

		return error;

	case EVIOCRMFF:
		return input_ff_erase(dev, (int)(unsigned long) p, file);

	case EVIOCGEFFECTS:
		i = test_bit(EV_FF, dev->evbit) ?
				dev->ff->max_effects : 0;
		if (put_user(i, ip))
			return -EFAULT;
		return 0;

	case EVIOCGRAB:
		if (p)
			return evdev_grab(evdev, client);
		else
			return evdev_ungrab(evdev, client);

	default:

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

		if (_IOC_DIR(cmd) == _IOC_READ) {

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

				unsigned 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;
				case EV_SW:  bits = dev->swbit;  len = SW_MAX;  break;
				default: return -EINVAL;
			}
				return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
			}

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
				return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
						    p, compat_mode);

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
				return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
						    p, compat_mode);

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
				return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
						    p, compat_mode);

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
				return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
						    p, compat_mode);

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
				return str_to_user(dev->name, _IOC_SIZE(cmd), p);

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
				return str_to_user(dev->phys, _IOC_SIZE(cmd), p);

			if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
				return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);

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

				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(p, &abs, sizeof(struct input_absinfo)))
					return -EFAULT;

				return 0;
			}

		}

		if (_IOC_DIR(cmd) == _IOC_WRITE) {

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

				t = _IOC_NR(cmd) & ABS_MAX;

				if (copy_from_user(&abs, p,
						sizeof(struct input_absinfo)))
					return -EFAULT;

				/*
				 * Take event lock to ensure that we are not
				 * changing device parameters in the middle
				 * of event.
				 */
				spin_lock_irq(&dev->event_lock);

				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;

				spin_unlock_irq(&dev->event_lock);

				return 0;
			}
		}
	}
	return -EINVAL;
}

static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
				void __user *p, int compat_mode)
{
	struct evdev_client *client = file->private_data;
	struct evdev *evdev = client->evdev;
	int retval;

	retval = mutex_lock_interruptible(&evdev->mutex);
	if (retval)
		return retval;

	if (!evdev->exist) {
		retval = -ENODEV;
		goto out;
	}

	retval = evdev_do_ioctl(file, cmd, p, compat_mode);

 out:
	mutex_unlock(&evdev->mutex);
	return retval;
}

static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
}

#ifdef CONFIG_COMPAT
static long evdev_ioctl_compat(struct file *file,
				unsigned int cmd, unsigned long arg)
{
	return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
}
#endif

static const struct file_operations evdev_fops = {
	.owner		= THIS_MODULE,
	.read		= evdev_read,
	.write		= evdev_write,
	.poll		= evdev_poll,
	.open		= evdev_open,
	.release	= evdev_release,
	.unlocked_ioctl	= evdev_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= evdev_ioctl_compat,
#endif
	.fasync		= evdev_fasync,
	.flush		= evdev_flush
};

static int evdev_install_chrdev(struct evdev *evdev)
{
	/*
	 * No need to do any locking here as calls to connect and
	 * disconnect are serialized by the input core
	 */
	evdev_table[evdev->minor] = evdev;
	return 0;
}

static void evdev_remove_chrdev(struct evdev *evdev)
{
	/*
	 * Lock evdev table to prevent race with evdev_open()
	 */
	mutex_lock(&evdev_table_mutex);
	evdev_table[evdev->minor] = NULL;
	mutex_unlock(&evdev_table_mutex);
}

/*
 * Mark device non-existent. This disables writes, ioctls and
 * prevents new users from opening the device. Already posted
 * blocking reads will stay, however new ones will fail.
 */
static void evdev_mark_dead(struct evdev *evdev)
{
	mutex_lock(&evdev->mutex);
	evdev->exist = 0;
	mutex_unlock(&evdev->mutex);
}

static void evdev_cleanup(struct evdev *evdev)
{
	struct input_handle *handle = &evdev->handle;

	evdev_mark_dead(evdev);
	evdev_hangup(evdev);
	evdev_remove_chrdev(evdev);

	/* evdev is marked dead so no one else accesses evdev->open */
	if (evdev->open) {
		input_flush_device(handle, NULL);
		input_close_device(handle);
	}
}

/*
 * Create new evdev device. Note that input core serializes calls
 * to connect and disconnect so we don't need to lock evdev_table here.
 */
static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
			 const struct input_device_id *id)
{
	struct evdev *evdev;
	int minor;
	int error;

	for (minor = 0; minor < EVDEV_MINORS; minor++)
		if (!evdev_table[minor])
			break;

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

	evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
	if (!evdev)
		return -ENOMEM;

	INIT_LIST_HEAD(&evdev->client_list);
	spin_lock_init(&evdev->client_lock);
	mutex_init(&evdev->mutex);
	init_waitqueue_head(&evdev->wait);

	snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
	evdev->exist = 1;
	evdev->minor = minor;

	evdev->handle.dev = dev;
	evdev->handle.name = evdev->name;
	evdev->handle.handler = handler;
	evdev->handle.private = evdev;

	strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id));
	evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
	evdev->dev.class = &input_class;
	evdev->dev.parent = &dev->dev;
	evdev->dev.release = evdev_free;
	device_initialize(&evdev->dev);

	error = input_register_handle(&evdev->handle);
	if (error)
		goto err_free_evdev;

	error = evdev_install_chrdev(evdev);
	if (error)
		goto err_unregister_handle;

	error = device_add(&evdev->dev);
	if (error)
		goto err_cleanup_evdev;

	return 0;

 err_cleanup_evdev:
	evdev_cleanup(evdev);
 err_unregister_handle:
	input_unregister_handle(&evdev->handle);
 err_free_evdev:
	put_device(&evdev->dev);
	return error;
}

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

	device_del(&evdev->dev);
	evdev_cleanup(evdev);
	input_unregister_handle(handle);
	put_device(&evdev->dev);
}

static const 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)
{
	return input_register_handler(&evdev_handler);
}

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

module_init(evdev_init);
module_exit(evdev_exit);

MODULE_AUTHOR("Vojtech Pavlik <[e-mail]>");
MODULE_DESCRIPTION("Input driver event char devices");
MODULE_LICENSE("GPL");