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V4L/DVB (12541): v4l: remove video_register_device_index
video_register_device_index is never actually called, instead the stream index number is always calculated automatically. This patch removes this function and simplifies the internal get_index function since that can now always just return the first free index. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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53dacb1570
commit
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3 changed files with 20 additions and 54 deletions
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@ -500,17 +500,11 @@ first free number.
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Whenever a device node is created some attributes are also created for you.
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Whenever a device node is created some attributes are also created for you.
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If you look in /sys/class/video4linux you see the devices. Go into e.g.
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If you look in /sys/class/video4linux you see the devices. Go into e.g.
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video0 and you will see 'name' and 'index' attributes. The 'name' attribute
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video0 and you will see 'name' and 'index' attributes. The 'name' attribute
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is the 'name' field of the video_device struct. The 'index' attribute is
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is the 'name' field of the video_device struct.
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a device node index that can be assigned by the driver, or that is calculated
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for you.
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If you call video_register_device(), then the index is just increased by
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The 'index' attribute is the index of the device node: for each call to
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1 for each device node you register. The first video device node you register
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video_register_device() the index is just increased by 1. The first video
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always starts off with 0.
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device node you register always starts with index 0.
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Alternatively you can call video_register_device_index() which is identical
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to video_register_device(), but with an extra index argument. Here you can
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pass a specific index value (between 0 and 31) that should be used.
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Users can setup udev rules that utilize the index attribute to make fancy
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Users can setup udev rules that utilize the index attribute to make fancy
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device names (e.g. 'mpegX' for MPEG video capture device nodes).
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device names (e.g. 'mpegX' for MPEG video capture device nodes).
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@ -520,8 +514,7 @@ After the device was successfully registered, then you can use these fields:
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- vfl_type: the device type passed to video_register_device.
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- vfl_type: the device type passed to video_register_device.
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- minor: the assigned device minor number.
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- minor: the assigned device minor number.
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- num: the device kernel number (i.e. the X in videoX).
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- num: the device kernel number (i.e. the X in videoX).
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- index: the device index number (calculated or set explicitly using
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- index: the device index number.
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video_register_device_index).
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If the registration failed, then you need to call video_device_release()
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If the registration failed, then you need to call video_device_release()
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to free the allocated video_device struct, or free your own struct if the
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to free the allocated video_device struct, or free your own struct if the
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@ -299,32 +299,28 @@ static const struct file_operations v4l2_fops = {
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};
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};
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/**
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/**
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* get_index - assign stream number based on parent device
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* get_index - assign stream index number based on parent device
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* @vdev: video_device to assign index number to, vdev->parent should be assigned
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* @vdev: video_device to assign index number to, vdev->parent should be assigned
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* @num: -1 if auto assign, requested number otherwise
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*
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*
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* Note that when this is called the new device has not yet been registered
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* Note that when this is called the new device has not yet been registered
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* in the video_device array.
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* in the video_device array, but it was able to obtain a minor number.
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*
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*
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* Returns -ENFILE if num is already in use, a free index number if
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* This means that we can always obtain a free stream index number since
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* successful.
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* the worst case scenario is that there are VIDEO_NUM_DEVICES - 1 slots in
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* use of the video_device array.
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*
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* Returns a free index number.
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*/
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*/
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static int get_index(struct video_device *vdev, int num)
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static int get_index(struct video_device *vdev)
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{
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{
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/* This can be static since this function is called with the global
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/* This can be static since this function is called with the global
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videodev_lock held. */
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videodev_lock held. */
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static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
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static DECLARE_BITMAP(used, VIDEO_NUM_DEVICES);
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int i;
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int i;
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if (num >= VIDEO_NUM_DEVICES) {
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/* Some drivers do not set the parent. In that case always return 0. */
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printk(KERN_ERR "videodev: %s num is too large\n", __func__);
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return -EINVAL;
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}
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/* Some drivers do not set the parent. In that case always return
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num or 0. */
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if (vdev->parent == NULL)
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if (vdev->parent == NULL)
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return num >= 0 ? num : 0;
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return 0;
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bitmap_zero(used, VIDEO_NUM_DEVICES);
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bitmap_zero(used, VIDEO_NUM_DEVICES);
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@ -335,30 +331,15 @@ static int get_index(struct video_device *vdev, int num)
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}
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}
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}
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}
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if (num >= 0) {
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return find_first_zero_bit(used, VIDEO_NUM_DEVICES);
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if (test_bit(num, used))
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return -ENFILE;
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return num;
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}
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i = find_first_zero_bit(used, VIDEO_NUM_DEVICES);
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return i == VIDEO_NUM_DEVICES ? -ENFILE : i;
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}
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}
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int video_register_device(struct video_device *vdev, int type, int nr)
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{
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return video_register_device_index(vdev, type, nr, -1);
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}
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EXPORT_SYMBOL(video_register_device);
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/**
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/**
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* video_register_device_index - register video4linux devices
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* video_register_device - register video4linux devices
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* @vdev: video device structure we want to register
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* @vdev: video device structure we want to register
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* @type: type of device to register
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* @type: type of device to register
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* @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
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* @nr: which device number (0 == /dev/video0, 1 == /dev/video1, ...
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* -1 == first free)
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* -1 == first free)
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* @index: stream number based on parent device;
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* -1 if auto assign, requested number otherwise
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*
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*
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* The registration code assigns minor numbers based on the type
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* The registration code assigns minor numbers based on the type
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* requested. -ENFILE is returned in all the device slots for this
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* requested. -ENFILE is returned in all the device slots for this
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@ -377,8 +358,7 @@ EXPORT_SYMBOL(video_register_device);
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*
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*
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* %VFL_TYPE_RADIO - A radio card
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* %VFL_TYPE_RADIO - A radio card
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*/
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*/
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int video_register_device_index(struct video_device *vdev, int type, int nr,
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int video_register_device(struct video_device *vdev, int type, int nr)
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int index)
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{
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{
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int i = 0;
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int i = 0;
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int ret;
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int ret;
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@ -481,14 +461,9 @@ int video_register_device_index(struct video_device *vdev, int type, int nr,
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set_bit(nr, video_nums[type]);
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set_bit(nr, video_nums[type]);
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/* Should not happen since we thought this minor was free */
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/* Should not happen since we thought this minor was free */
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WARN_ON(video_device[vdev->minor] != NULL);
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WARN_ON(video_device[vdev->minor] != NULL);
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ret = vdev->index = get_index(vdev, index);
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vdev->index = get_index(vdev);
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mutex_unlock(&videodev_lock);
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mutex_unlock(&videodev_lock);
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if (ret < 0) {
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printk(KERN_ERR "%s: get_index failed\n", __func__);
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goto cleanup;
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}
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/* Part 3: Initialize the character device */
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/* Part 3: Initialize the character device */
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vdev->cdev = cdev_alloc();
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vdev->cdev = cdev_alloc();
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if (vdev->cdev == NULL) {
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if (vdev->cdev == NULL) {
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@ -543,7 +518,7 @@ int video_register_device_index(struct video_device *vdev, int type, int nr,
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vdev->minor = -1;
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vdev->minor = -1;
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return ret;
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return ret;
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}
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}
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EXPORT_SYMBOL(video_register_device_index);
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EXPORT_SYMBOL(video_register_device);
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/**
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/**
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* video_unregister_device - unregister a video4linux device
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* video_unregister_device - unregister a video4linux device
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@ -100,8 +100,6 @@ struct video_device
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Also note that vdev->minor is set to -1 if the registration failed. */
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Also note that vdev->minor is set to -1 if the registration failed. */
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int __must_check video_register_device(struct video_device *vdev, int type, int nr);
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int __must_check video_register_device(struct video_device *vdev, int type, int nr);
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int __must_check video_register_device_index(struct video_device *vdev,
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int type, int nr, int index);
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/* Unregister video devices. Will do nothing if vdev == NULL or
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/* Unregister video devices. Will do nothing if vdev == NULL or
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vdev->minor < 0. */
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vdev->minor < 0. */
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