[PATCH 1/4] drm: add plane support

[Joonyoung Shim]

2011/7/22 Jesse Barnes <jbarnes at virtuousgeek.org>:
> On Thu, 21 Jul 2011 19:30:00 +0900
> Joonyoung Shim <dofmind at gmail.com> wrote:
>
>> Hi,
>>
>> simple questions :)
>>
>> 2011/6/21 Jesse Barnes <jbarnes at virtuousgeek.org>:
>> > Planes are a bit like half-CRTCs.  They have a location and fb, but
>> > don't drive outputs directly.  Add support for handling them to the core
>> > KMS code.
>> >
>> > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
>> > ---
>> >  drivers/gpu/drm/drm_crtc.c |  235 +++++++++++++++++++++++++++++++++++++++++++-
>> >  drivers/gpu/drm/drm_drv.c  |    3 +
>> >  include/drm/drm.h          |    3 +
>> >  include/drm/drm_crtc.h     |   73 ++++++++++++++-
>> >  include/drm/drm_mode.h     |   35 +++++++
>> >  5 files changed, 346 insertions(+), 3 deletions(-)
>> >
>>
>> snip
>>
>> > diff --git a/include/drm/drm_mode.h b/include/drm/drm_mode.h
>> > index c4961ea..fa6d348 100644
>> > --- a/include/drm/drm_mode.h
>> > +++ b/include/drm/drm_mode.h
>> > @@ -120,6 +120,41 @@ struct drm_mode_crtc {
>> >        struct drm_mode_modeinfo mode;
>> >  };
>> >
>> > +/* Planes blend with or override other bits on the CRTC */
>> > +struct drm_mode_set_plane {
>> > +       __u32 plane_id;
>> > +       __u32 crtc_id;
>> > +       __u32 fb_id; /* fb object contains surface format type */
>> > +
>> > +       /* Signed dest location allows it to be partially off screen */
>> > +       __s32 crtc_x, crtc_y;
>>
>> Is this location offset from base(0, 0) of fb for plane, or from base
>> of crtc(mode)?
>
> This is the offset on the crtc specifically (which could be displaying
> a nonzero offset of a given fb).
>

Then if i want to use the specific area of a given fb for overlay, how
can we know the offset on a given fb?
In other words, can we use the specific offset from fb to origin(base
pointer) of plane? or can we use each overlays from each specific
offsets of one fb?

Thanks.

-- 
- Joonyoung Shim