V4L/DVB (10988): v4l2-dev: use parent field if the v4l2_device has no parent set.
Normally the parent device of v4l2_device is used as the video device node's parent. But if it was not set, then use the parent field in the video_device struct. This is needed in the cx88 driver, which has one core v4l2_device but creates multiple pci devices (one each for raw and mpeg video). So you cannot associate the core v4l2_device with a particular PCI device, but you can do that for each video_device. Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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@ -91,7 +91,8 @@ NULL, then you *must* setup v4l2_dev->name before calling v4l2_device_register.
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The first 'dev' argument is normally the struct device pointer of a pci_dev,
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usb_device or platform_device. It is rare for dev to be NULL, but it happens
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with ISA devices, for example.
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with ISA devices or when one device creates multiple PCI devices, thus making
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it impossible to associate v4l2_dev with a particular parent.
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You unregister with:
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@ -414,6 +415,15 @@ You should also set these fields:
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- ioctl_ops: if you use the v4l2_ioctl_ops to simplify ioctl maintenance
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(highly recommended to use this and it might become compulsory in the
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future!), then set this to your v4l2_ioctl_ops struct.
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- parent: you only set this if v4l2_device was registered with NULL as
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the parent device struct. This only happens in cases where one hardware
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device has multiple PCI devices that all share the same v4l2_device core.
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The cx88 driver is an example of this: one core v4l2_device struct, but
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it is used by both an raw video PCI device (cx8800) and a MPEG PCI device
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(cx8802). Since the v4l2_device cannot be associated with a particular
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PCI device it is setup without a parent device. But when the struct
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video_device is setup you do know which parent PCI device to use.
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If you use v4l2_ioctl_ops, then you should set either .unlocked_ioctl or
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.ioctl to video_ioctl2 in your v4l2_file_operations struct.
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@ -395,7 +395,7 @@ int video_register_device_index(struct video_device *vdev, int type, int nr,
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vdev->vfl_type = type;
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vdev->cdev = NULL;
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if (vdev->v4l2_dev)
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if (vdev->v4l2_dev && vdev->v4l2_dev->dev)
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vdev->parent = vdev->v4l2_dev->dev;
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/* Part 2: find a free minor, kernel number and device index. */
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