*/
static struct video_device *video_device[VIDEO_NUM_DEVICES];
static DEFINE_MUTEX(videodev_lock);
-static DECLARE_BITMAP(video_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
+static DECLARE_BITMAP(devnode_nums[VFL_TYPE_MAX], VIDEO_NUM_DEVICES);
+
+/* Device node utility functions */
+
+/* Note: these utility functions all assume that vfl_type is in the range
+ [0, VFL_TYPE_MAX-1]. */
+
+#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
+/* Return the bitmap corresponding to vfl_type. */
+static inline unsigned long *devnode_bits(int vfl_type)
+{
+ /* Any types not assigned to fixed minor ranges must be mapped to
+ one single bitmap for the purposes of finding a free node number
+ since all those unassigned types use the same minor range. */
+ int idx = (vfl_type > VFL_TYPE_VTX) ? VFL_TYPE_MAX - 1 : vfl_type;
+
+ return devnode_nums[idx];
+}
+#else
+/* Return the bitmap corresponding to vfl_type. */
+static inline unsigned long *devnode_bits(int vfl_type)
+{
+ return devnode_nums[vfl_type];
+}
+#endif
+
+/* Mark device node number vdev->num as used */
+static inline void devnode_set(struct video_device *vdev)
+{
+ set_bit(vdev->num, devnode_bits(vdev->vfl_type));
+}
+
+/* Mark device node number vdev->num as unused */
+static inline void devnode_clear(struct video_device *vdev)
+{
+ clear_bit(vdev->num, devnode_bits(vdev->vfl_type));
+}
+
+/* Try to find a free device node number in the range [from, to> */
+static inline int devnode_find(struct video_device *vdev, int from, int to)
+{
+ return find_next_zero_bit(devnode_bits(vdev->vfl_type), to, from);
+}
struct video_device *video_device_alloc(void)
{
the release() callback. */
vdev->cdev = NULL;
- /* Mark minor as free */
- clear_bit(vdev->num, video_nums[vdev->vfl_type]);
+ /* Mark device node number as free */
+ devnode_clear(vdev);
mutex_unlock(&videodev_lock);
if (!vdev->fops->read)
return -EINVAL;
- if (video_is_unregistered(vdev))
+ if (!video_is_registered(vdev))
return -EIO;
return vdev->fops->read(filp, buf, sz, off);
}
if (!vdev->fops->write)
return -EINVAL;
- if (video_is_unregistered(vdev))
+ if (!video_is_registered(vdev))
return -EIO;
return vdev->fops->write(filp, buf, sz, off);
}
{
struct video_device *vdev = video_devdata(filp);
- if (!vdev->fops->poll || video_is_unregistered(vdev))
+ if (!vdev->fops->poll || !video_is_registered(vdev))
return DEFAULT_POLLMASK;
return vdev->fops->poll(filp, poll);
}
if (!vdev->fops->get_unmapped_area)
return -ENOSYS;
- if (video_is_unregistered(vdev))
+ if (!video_is_registered(vdev))
return -ENODEV;
return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
}
{
struct video_device *vdev = video_devdata(filp);
- if (!vdev->fops->mmap ||
- video_is_unregistered(vdev))
+ if (!vdev->fops->mmap || !video_is_registered(vdev))
return -ENODEV;
return vdev->fops->mmap(filp, vm);
}
vdev = video_devdata(filp);
/* return ENODEV if the video device has been removed
already or if it is not registered anymore. */
- if (vdev == NULL || video_is_unregistered(vdev)) {
+ if (vdev == NULL || !video_is_registered(vdev)) {
mutex_unlock(&videodev_lock);
return -ENODEV;
}
* video_register_device - register video4linux devices
* @vdev: video device structure we want to register
* @type: type of device to register
- * @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
+ * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ...
* -1 == first free)
+ * @warn_if_nr_in_use: warn if the desired device node number
+ * was already in use and another number was chosen instead.
*
- * The registration code assigns minor numbers based on the type
- * requested. -ENFILE is returned in all the device slots for this
- * category are full. If not then the minor field is set and the
- * driver initialize function is called (if non %NULL).
+ * The registration code assigns minor numbers and device node numbers
+ * based on the requested type and registers the new device node with
+ * the kernel.
+ * An error is returned if no free minor or device node number could be
+ * found, or if the registration of the device node failed.
*
* Zero is returned on success.
*
*
* %VFL_TYPE_RADIO - A radio card
*/
-int video_register_device(struct video_device *vdev, int type, int nr)
+static int __video_register_device(struct video_device *vdev, int type, int nr,
+ int warn_if_nr_in_use)
{
int i = 0;
int ret;
if (vdev->v4l2_dev && vdev->v4l2_dev->dev)
vdev->parent = vdev->v4l2_dev->dev;
- /* Part 2: find a free minor, kernel number and device index. */
+ /* Part 2: find a free minor, device node number and device index. */
#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
/* Keep the ranges for the first four types for historical
* reasons.
}
#endif
- /* Pick a minor number */
+ /* Pick a device node number */
mutex_lock(&videodev_lock);
- nr = find_next_zero_bit(video_nums[type], minor_cnt, nr == -1 ? 0 : nr);
+ nr = devnode_find(vdev, nr == -1 ? 0 : nr, minor_cnt);
if (nr == minor_cnt)
- nr = find_first_zero_bit(video_nums[type], minor_cnt);
+ nr = devnode_find(vdev, 0, minor_cnt);
if (nr == minor_cnt) {
- printk(KERN_ERR "could not get a free kernel number\n");
+ printk(KERN_ERR "could not get a free device node number\n");
mutex_unlock(&videodev_lock);
return -ENFILE;
}
#ifdef CONFIG_VIDEO_FIXED_MINOR_RANGES
- /* 1-on-1 mapping of kernel number to minor number */
+ /* 1-on-1 mapping of device node number to minor number */
i = nr;
#else
- /* The kernel number and minor numbers are independent */
+ /* The device node number and minor numbers are independent, so
+ we just find the first free minor number. */
for (i = 0; i < VIDEO_NUM_DEVICES; i++)
if (video_device[i] == NULL)
break;
#endif
vdev->minor = i + minor_offset;
vdev->num = nr;
- set_bit(nr, video_nums[type]);
+ devnode_set(vdev);
+
/* Should not happen since we thought this minor was free */
WARN_ON(video_device[vdev->minor] != NULL);
vdev->index = get_index(vdev);
vdev->dev.devt = MKDEV(VIDEO_MAJOR, vdev->minor);
if (vdev->parent)
vdev->dev.parent = vdev->parent;
- dev_set_name(&vdev->dev, "%s%d", name_base, nr);
+ dev_set_name(&vdev->dev, "%s%d", name_base, vdev->num);
ret = device_register(&vdev->dev);
if (ret < 0) {
printk(KERN_ERR "%s: device_register failed\n", __func__);
reference to the device goes away. */
vdev->dev.release = v4l2_device_release;
+ if (nr != -1 && nr != vdev->num && warn_if_nr_in_use)
+ printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__,
+ name_base, nr, video_device_node_name(vdev));
+
/* Part 5: Activate this minor. The char device can now be used. */
+ set_bit(V4L2_FL_REGISTERED, &vdev->flags);
mutex_lock(&videodev_lock);
video_device[vdev->minor] = vdev;
mutex_unlock(&videodev_lock);
mutex_lock(&videodev_lock);
if (vdev->cdev)
cdev_del(vdev->cdev);
- clear_bit(vdev->num, video_nums[type]);
+ devnode_clear(vdev);
mutex_unlock(&videodev_lock);
/* Mark this video device as never having been registered. */
vdev->minor = -1;
return ret;
}
+
+int video_register_device(struct video_device *vdev, int type, int nr)
+{
+ return __video_register_device(vdev, type, nr, 1);
+}
EXPORT_SYMBOL(video_register_device);
+int video_register_device_no_warn(struct video_device *vdev, int type, int nr)
+{
+ return __video_register_device(vdev, type, nr, 0);
+}
+EXPORT_SYMBOL(video_register_device_no_warn);
+
/**
* video_unregister_device - unregister a video4linux device
* @vdev: the device to unregister
void video_unregister_device(struct video_device *vdev)
{
/* Check if vdev was ever registered at all */
- if (!vdev || vdev->minor < 0)
+ if (!vdev || !video_is_registered(vdev))
return;
mutex_lock(&videodev_lock);
- set_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
+ clear_bit(V4L2_FL_REGISTERED, &vdev->flags);
mutex_unlock(&videodev_lock);
device_unregister(&vdev->dev);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff