Announcing s3c64xx XWindows fbdrv w/ XAA+XVideo+HWcursor
David F. Carlson
dave at chronolytics.com
Fri Sep 25 08:47:18 EDT 2009
According to Ben Dooks:
>
> On Thu, Sep 24, 2009 at 01:42:20PM -0400, David F. Carlson wrote:
> >
> > S3C6410 based Xwindows fbdev with
> > o XAA accelerated fills, lines, expands, blits, offscreen pixmaps/stipples
> > o Alpha-blended HWCursor
> > o XVideo Support (using the Samsung Post-Processor colorspace driver)
> > o Tested with the Maemo Mer kernel 2.6.24.7 because...
> >
> Are the necessary changes for the s3cfb postable to the list to start
> the review process for them?
I have a near-term problem which is that I am still developing on 2.6.24.7
because my attempts to use next-s3c failed to produce an image that would
start XWindows. (SDHC, pwm, lcd support, etc.) I am not complaining, just
explaining. Patching without testing is not a good place to be.
That being said, you seem to have a preferred direction for what should be
in the s3c-fb. Allocation of offscreen memory at config time seems doable
with static testing. Is a per-screen Kconfig desirable? How should DBE and
offscreen memory play nice? (Or should they be mutually exclusive?) With
a PP handling color space conversion and onscreen bit, I am not sure
DBE buys much.
Adding the MMIO mmap interface is also "trivial". (If it is desirable.
I will not waste my time if it is "pre-rejected")
It also appears that even Samsung latests gits omit the g2d driver. Is the
plan to fold that register space into s3c-fb or "something else"? I need
suspend/resume support in the kernel for the XAA to "work". But a contig
vaddr mmap of the display controller and g2d dis-contig physical spaces
would suit me fine. We need an answer to "how do we access the g2d space?"
I am not a huge fan of the PP driver API, but it works. I also think that
XVideo is the right way for user space to access the PP. XWindows will "own"
the device (ie., baseband not shared). I would be willing to get you diffs
for PP (or Samsung could).
>
> > This driver is pretty much hardcoded for s3c64xx. If kernel hooks for
> > describing configuration this driver base could be expanded to
> > support many s3c variants (with g2d and pp).
>
> It would be good to get the discussion about these items going before
> we get too much further down the development process.
I have tried to contact Samsung but I get dead-air.
I know you (Ben) and Harald have had some discussion, but I am out of the
loop as to how Samsung/Harald/Ben/others want this thing to look when we
are done.
I have placed a marker.
And I am very willing to "get this right". But part of my problem is that I
have access to 6410 only. I do not understand the differences amongst the
10+ devices in the s3c family. With very few exceptions (Ben? :-) I am not
sure any out of Samsung really understands the whole s3c family.
David F. Carlson Chronolytics, Inc. Rochester, NY
mailto:dave at chronolytics.com http://www.chronolytics.com
"The faster I go, the behinder I get." --Lewis Carroll
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