Re: [REVIEWv2 PATCH 12/12] v4l2-framework: update documentation

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

Thanks for the patch.

On Wednesday 12 June 2013 17:01:02 Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> 'parent' was renamed to 'dev_parent'. Clarify how/when this should be used.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

with a small comment below.

> ---
>  Documentation/video4linux/v4l2-framework.txt |   17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/video4linux/v4l2-framework.txt
> b/Documentation/video4linux/v4l2-framework.txt index 24353ec..3944d5c
> 100644
> --- a/Documentation/video4linux/v4l2-framework.txt
> +++ b/Documentation/video4linux/v4l2-framework.txt
> @@ -574,9 +574,13 @@ of the video device exits.
>  The default video_device_release() callback just calls kfree to free the
>  allocated memory.
> 
> +There is also a video_device_release_empty() function that does nothing
> +(is empty) and can be used if the struct is embedded and there is nothing
> +to do when it is released.
> +
>  You should also set these fields:
> 
> -- v4l2_dev: set to the v4l2_device parent device.
> +- v4l2_dev: must be set to the v4l2_device parent device.
> 
>  - name: set to something descriptive and unique.
> 
> @@ -613,15 +617,16 @@ You should also set these fields:
>    If you want to have a separate priority state per (group of) device
> node(s), then you can point it to your own struct v4l2_prio_state.
> 
> -- parent: you only set this if v4l2_device was registered with NULL as
> +- dev_parent: you only set this if v4l2_device was registered with NULL as
>    the parent device struct. This only happens in cases where one hardware
>    device has multiple PCI devices that all share the same v4l2_device core.
> 
>    The cx88 driver is an example of this: one core v4l2_device struct, but
> -  it is used by both an raw video PCI device (cx8800) and a MPEG PCI device
> -  (cx8802). Since the v4l2_device cannot be associated with a particular
> -  PCI device it is setup without a parent device. But when the struct
> -  video_device is setup you do know which parent PCI device to use.
> +  it is used by both a raw video PCI device (cx8800) and a MPEG PCI device
> +  (cx8802). Since the v4l2_device cannot be associated with a two PCI

s/a two/two/

> +  devices at the same time it is setup without a parent device. But when
> +  the struct video_device is initialized you *do* know which parent PCI
> +  device to use and  so you set dev_device to the correct PCI device.
> 
>  - flags: optional. Set to V4L2_FL_USE_FH_PRIO if you want to let the
> framework handle the VIDIOC_G/S_PRIORITY ioctls. This requires that you use
> struct
-- 
Regards,

Laurent Pinchart